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    • 专利摘要:
    air driven gearbox delivery system. a dosing system to deliver reducer to an internal combustion engine exhaust gas treatment system using air driven hydraulic pumps to closed loop control of reducer pressure and a two-stage pwm control method to control the rate of dosage. Reducer residue in the dosing system is purged by the use of compressed air after a dosing process is completed, and when air-driven hydraulic pumps are positioned inside a reducer tank, dedicated heating device(s) for the pumps it is not necessary. air-driven hydraulic pumps can also use low-pressure compressed air, and the closed-loop pressure control in conjunction with the two-stage pwm control enables metering accuracy insensitive to pressure variations in compressed air. these new features enable the dosing system to use a variety of compressed air sources, including an engine turbo.
    公开号:BR112014032495B1
    申请号:R112014032495-6
    申请日:2013-08-17
    公开日:2021-06-01
    发明作者:Mi Yan；Baohua Qi
    申请人:Nanjing Keyi Environmental Protection Science And Technology Co.Ltd；
    IPC主号:
    专利说明:

    FIELD OF THE INVENTION
    [001] This present application claims priority from provisional application US 61/575,469 having the same title as the present invention and filed on 08/22/2011.
    [002] The present invention relates to an apparatus and method for delivering reducer to an internal combustion engine exhaust gas treatment system to remove regulated species in exhaust gas, and more specifically to an apparatus and method using pump air-driven hydraulics to deliver liquid reducing agents to an internal combustion engine exhaust gas treatment system. BACKGROUND OF THE INVENTION
    [003] Environmentally harmful species in the exhaust gas emitted by an internal combustion engine, such as hydrocarbons (HC), carbon monoxide (CO), particulate matter (PM) and nitric oxides (NOx) are regulated species that need to be removed of the exhaust gas. In lean combustion engines, because of the large amount of excess oxygen, passive media without extra dosing agents, such as those using a three-way catalyst, are usually not able to effectively remove oxidative NOx species, such as in most spark ignition engines. To reduce NOx in lean combustion engines, a variety of active media with reducing agents (reducing) being metered into exhaust gas are developed. In these technologies, normally the reducer is measured and injected into the exhaust gas, and the resulting mixture flows into an SCR (Selective Catalytic Reduction) catalyst, where the reducer selectively reacts with NOx generating non-poisonous species such as nitrogen, dioxide carbon and water.
    [004] A variety of reducers, such as ammonia (NH3), HC and hydrogen (H2), can be used in SCR systems. Among them, SCR with ammonia is used more widely because of high conversion efficiency and wide temperature window. Ammonia can be directly dosed. However, because of safety issues and difficulties in handling pure ammonia, typically urea solution is used in SCR systems with ammonia. Urea can be thermalized and hydrolyzed to ammonia in exhaust gas.
    [005] Typically, in an SCR control system, the required ammonia dosing rate is calculated in an ECU (Engine Control Unit). Then, according to the urea to ammonia ratio, the required urea flow rate is calculated and the dose rate command is sent to a dosing system, where urea solution is measured and injected into the exhaust gas. Generally speaking, similar to supply control, there are two methods for measuring reducer. One method is to use a metering pump, with which the reducer flow rate is precisely controlled by controlling the pump rate. The other method is more similar to that used in a common rail supply control system. In this method, a pressure is developed and kept constant in a reducer rail or BUFFER, and the reducer flow rate is controlled by adjusting the opening time of an injector, which is fluidly connected to the BUFFER, in a cycle of repeat control.
    [006] Reducer atomization is important for SCR conversion efficiency, especially in a urea SCR system, where metered urea needs to be thermalized and hydrolyzed to ammonia and the thermal energy supplied through the exhaust gas is limited. In the first gearbox measurement method, although the control is simple, the gearbox pressure is not controlled. Therefore, in order to have a good atomization, in addition to having a well-designed nozzle facilitating atomization, normally the reducer dosage needs to be mixed with an extra air supply providing a continuous air flow. The requirements of a continuous flow of air and a precisely controlled metering pump limit the application of this method. The second reducer measurement method does not need an extra air supply to facilitate atomization, since at high pressure the reducer injected by a well-designed nozzle has good atomization. However, in this method, because of the pressure control requirement, typically a liquid pump, such as a membrane pump, driven by a motor, is required to establish and maintain rail pressure, and an engine control system. complex is required.
    [007] Additionally, to avoid reducer frozen at low ambient temperature, reducer residues inside the dosing system need to be purged before the dosing system is turned off. In a system using the first reducer measurement method, an air supply can be used to push the reducer residue back into the tank, while in this one using the second method, an extra reducer flow control is needed to drive the residue. of reducer back. In dosing systems that have reducer residue in connecting lines, line heating means are also required. Different from reducer tank heating control, line heating is distributed heating and it is difficult and expensive to use closed loop controls. Except using special PTC (Positive Temperature Coefficient) heaters, heating energy and line durability need to be carefully balanced to avoid damage from local overheating.
    [008] To decrease the complexity of a gearbox dosing system while at the same time achieving good performance, a primary objective of the present invention is to provide a gearbox dosing apparatus using air driven hydraulic pumps with a simple pressure control to build and maintain high pressure on a rail. The air driven hydraulic pump does not have a motor on the inside and therefore does not need electrical power and complex motor control to drive it. The air driven hydraulic pump also does not need a continuous air supply.
    [009] A further objective of the present invention is to provide a method of controlling dosing rate insensitive to variations in reducer pressure, so that accurate dosage rate is obtained under variable reducer pressure.
    [010] Another objective of the present invention is to provide a dosing apparatus with a hydraulic pump driven by air using compressed air generated by an engine turbo, so that extra air source is not required.
    [011] Also another objective of the present invention is to provide a means of control using compressed air to drain reducer waste back into the tank when a dosing process is completed.
    [012] Yet another object of the present invention is to provide a metering apparatus with an air-driven hydraulic pump positioned within a reducer tank, thus an extra heating means other than tank heating is not needed for the pump. SUMMARY OF THE INVENTION
    [013] The present invention provides an apparatus and method for delivering reducer to an exhaust gas treatment system of an internal combustion engine. More specifically, this apparatus includes a gearbox supply module with an air-driven hydraulic pump and a hydraulic BUFFER, a pressure sensor, a gearbox, a dosing control unit (DCU) and an injector. In one embodiment of the present invention, a pressure sensor is positioned on a hydraulic BUFFER to measure the reducer pressure provided by an air-driven hydraulic pump, which has an inlet port fluidly coupled to a source of compressed air by via a solenoid valve and an outlet port fluidly coupled to the environment via another solenoid valve and an optional silencer. The air driven hydraulic pump has a compression stroke and a suction stroke. The strokes and pressure in the air driven hydraulic pump are controlled by a DCU through operating the solenoid valves to supply and release air. In the compression stroke, the reducer pressure in the hydraulic BUFFER is controlled by a feedback controller in the DCU using detection values obtained from the pressure sensor, while in the suction stroke the pressure feedback controller is disabled and the reducer pressure is maintained by the hydraulic BUFFER. The hydraulic BUFFER is fluidly connected to an injector for gearbox dosing, and the injector inlet is coupled to the gearbox tank via a shut-off valve. After dosing, the shut-off valve is opened. The reducer residue in the air driven hydraulic pump and hydraulic BUFFER is drained under pressure in the pump, and that in the injector is purged. The gearbox dosing rate is controlled with a pulse width modulation (PWM) controller, which generates a PWM signal to drive the injector according to dosing commands. The PWM controller has two stages. The first-stage controller creates a first-stage PWM signal by periodically setting control parameters for the second-stage controller to generate a second-stage PWM signal. The values of the control parameters are calculated by the first controller stage according to the detection values obtained from the pressure sensor positioned inside the hydraulic BUFFER. In this way pressure variations are compensated by the PWM controller, and the dose rate accuracy is therefore insensitive to pressure variations. The gearbox temperature in the dosing system needs to be maintained above its freezing point to allow dosing in a low temperature environment. In the embodiment of the present invention, with the reducer waste purged by compressed air after dosing, the air driven hydraulic pump can be positioned inside the reducer tank to save heating means for the pump.
    [014] The air driven hydraulic pump is capable of working with a source of compressed air with a pressure lower than the reducer pressure in the hydraulic BUFFER. In another embodiment of the present invention, an air driven hydraulic pump has a piston within it. The piston has two surfaces and separates the inner space of the pump into an upper air chamber and a lower gear chamber. The surface facing the upper air chamber has a larger area than that of the surface facing the lower gear chamber, and thus a greater gear pressure is obtained. A fluid passage fluidly connects the upper air chamber to the lower gear chamber when the piston moves to a position to drain gear after metering.
    [015] To avoid possible pressure drop in a suction stroke, in another embodiment of the present invention, two air driven hydraulic pumps are used to provide continuous pressure feedback control. The two pumps are controlled by working alternately, that is, when the first pump is in compression stroke with pressure feedback control, a suction stroke is activated for the second pump, and the second pump goes to compression stroke when the first pump needs to be refilled using a suction stroke. This way, at any time, there is a pump in compression stroke with pressure feedback control, and in this way gearbox pressure in the hydraulic BUFFER is always kept constant.
    [016] Closed-loop pressure control and two-stage PWM control allow the reducer pressure to be insensitive to pressure variations in the compressed air supply, and the air-driven hydraulic pump is capable of working with a pressure of compressed air less than the reducer pressure. Also, because of the nature of the air driven hydraulic pump, the air consumption is equal to the reducer dosing amount, and continuous air flow is not required. These new features enable the dosing system of the present invention to use a variety of compressed air sources, including an engine turbo. BRIEF DESCRIPTION OF THE DRAWINGS
    [017] Figure 1 is a schematic representation of an internal combustion engine with an exhaust gas treatment system;
    [018] Figure 2a represents an air driven hydraulic pump system with a hydraulic BUFFER and solenoid control valves;
    [019] Figure 2b is a flowchart of a stroke control algorithm to control the air driven hydraulic pump system of figure 2a;
    [020] Figure 2c is a flowchart of a pressure control algorithm used to control the air driven hydraulic pump system of figure 2a;
    [021] Figure 3a is a diagrammatic and cross-sectional illustration of an air driven hydraulic pump system with a piston inside during normal dosing;
    [022] Figure 3b is a diagrammatic and cross-sectional illustration of an air driven hydraulic pump system with a piston inside in reducer purging;
    [023] Figure 4 represents an air-driven hydraulic pump positioned in a reducer tank;
    [024] Figure 5a is a block diagram with a flowchart of signals from a PWM controller to control reducer dosage rate;
    [025] Figure 5b is a block diagram with a flowchart of signals from the PWM control block in the PWM controller of figure 5a;
    [026] Figure 5c is a block diagram with signal flowchart of a PWM signal generation circuit;
    [027] Figure 5d is a flowchart of an interrupt service routine used in time and period determination control of Figure 5b;
    [028] Figure 5e is a graph of signal synchronization in a PWM signal generation using the interrupt service routine of Figure 5d;
    [029] Figure 6 shows a reducer pumping system with two hydraulic pumps driven by air;
    [030] Figure 7a is a flowchart of states of a gearbox delivery control;
    [031] Figure 7b is a flowchart of an interrupt service routine for pre-activation control;
    [032] Figure 7c is a flowchart of an interrupt service routine for purge control;
    [033] Figure 8 shows a hydraulic pump using compressed air supplied by an engine turbo. DETAILED DESCRIPTION OF THE INVENTION Reducer Delivery System
    [034] Referring to Figure 1, in an engine aftertreatment system, exhaust gas generated by an engine 100 enters a passage 166 through a manifold 101. In passage 166, a reducer injector 130 is installed . The injector solenoid valve 130 is controlled by a Dosing Control Unit (DCU) 140 via a signal line 145 connected to a port 136. pressure 131 fluidly connected to a port 133. To prevent damage from high temperature exhaust gas, engine coolant is cycled from an inlet port 134 to an outlet port 135. The reducer injected by the injector 130 mixture with exhaust gas, and through a mixer 161 the resulting gas enters a catalyst 163, where SCR reactions reduce NOx from the exhaust gas.
    [035] The reducer supply module 110 has a port 115 fluidly connected to port 133 of injector 130 with line 131 to deliver pressurized reducer supply to the injector. A pressure sensor (not shown in figure 1) reports pressure value within the reducer supply module to the DCU through a line 143 connected to a port 114. The reducer supply module extracts reducer from a reducer tank 120 through a port 117, a supply line 123 and a port 122 of the reductant tank. And compressed air enters the reducer supply module through an inlet port 111 to pressurize the reducer from the inside, while the reducer pressure is controlled by the DCU through line 146 connected to a port 116. Compressed air is released through an output port 112.
    [036] A tank level sensor and a temperature sensor respectively report the reducer level and temperature inside the reducer tank 120 to the DCU through lines 141 and 142, which are connected to a port 126. And the reducer tank is heated by engine coolant circulating in cycles through an inlet port 127 and an outlet port 128. Engine coolant flow is controlled by a solenoid shutoff valve 171 commanded by the DCU by the middle of a line 147. To prevent reducer residue within pressure line 131 from freezing to a low temperature when the motor is turned off, a return line 125 and port 121 are used as a passage for reducer to flow back to the tank in a purge process. Reducer flow within return line 125 is controlled by a shutoff valve 137 commanded by the DCU through line 148. Electric heaters 132, 129, 124 and 113 commanded by the DCU through line 144 are used to defrost reducer frozen in pressure line 131, return line 125, supply line 123 and reducer supply module 110, and to maintain the temperature above the reducer freezing point.
    [037] Reducer dose rate commands for the DCU are generated in the ECU according to catalyst inlet exhaust temperature reported by a sensor 162 via a line 155, catalyst output temperature reported by a sensor 164 by via a line 154, catalyst output NOx concentration obtained from a sensor 165 via a communication line 153, and engine information such as engine status, coolant and oil temperature, engine speed, fill rate, exhaust flow rate, NOx concentration and NO2/NOx ratio, obtained from sensors in engine 100 via line 152, or calculated using detection values obtained from the sensors. Air Actuated Hydraulic Pump
    [038] One modality of the reducer supply module 110 in figure 1 is an air driven pumping system depicted in figure 2a. In the pumping system, a pump body 200 holds reducer supplied by the reducer tank 120 through port 117 and a check valve (CHECK VALVE) 205, which prevents reducer from flowing back into the tank. On top of the pump body 200, a port 202 connected to a T 220 connector is used to pass compressed air in and out. One side of the T 220 connector is connected via a line 209 to the output of a normally open solenoid valve 201, the inlet of which is port 111 (figure 1) connected to a source of compressed air. The other side of the T-connector is connected to the inlet of a normally closed solenoid valve 203 via a line 211, and a muffler 204 is mounted on the outlet of the solenoid valve 203 to decrease air release noise. The muffler output is port 112 (figure 1). Under pressure inside the pump body, reducer is pressed into a hydraulic BUFFER body 210 through a port 208, a line 207, a port 218 and a check valve 217, which prevents reducer from flowing back for the pump body. A cover 212 is screwed to the hydraulic BUFFER body 210, and a spring 213 is positioned between a slot 221 in the cover 212 and another slot 222 in a piston 214, the lowermost position of which is defined by a stop 216. With the piston 214 and the hydraulic BUFFER body 210, a high pressure chamber 230 is enclosed, and an O-ring 215 in a groove 223 of the piston 214 prevents reducer in the high pressure chamber 230 from leaking out. Upon injector 130 being energized, reducer within chamber 230 flows through port 115, while pressure in chamber 230 is monitored by a pressure sensor 219 and pressure sensing values are sent to the DCU through port 114.
    [039] Reducer inside pump body 200 needs to be reset periodically, and pump pressure is controlled to stay constant after refill. Typically, a refill action of the pumping system is called a suction stroke, and a pumping action a compression stroke. Both stroke control and pump system pressure control are accomplished using the combination of controls for solenoid valves 201 and 203. The controls for the two valves have the four modes shown in the table below.

    [040] In Mode 0, both solenoid valves 201 and 203 are not energized, and the pump releases air to the environment. In Mode 1, once solenoid valve 201 is energized, the pump is disconnected from the environment. At the same time, the solenoid valve 203 is not energized and therefore air is trapped in the pump in this mode. Mode 2 is a special mode. In this mode, compressed air is released to the environment. Mode 2 can be used with a T Venturi 220 connector to create a low pressure in the pump body to facilitate refill on a suction stroke; however on a compression stroke Mode 2 should be avoided. Mode 3 is an aspiration mode. In this mode, solenoid valve 201 disconnects the pump from the environment, while solenoid valve 203 connects the pump to the compressed air supply.
    [041] The suction stroke and compression stroke are alternately activated in a pump control, and pump control can be accomplished using a service routine running periodically for a timer-based interruption. Referring to Figure 2b, in an exemplary pump control routine, a suction stroke activation state is first examined. If a suction stroke is activated, then the pump control goes to Mode 0, in which the pump releases air to the environment, and after the air pressure inside the pump body drops, under gravity or due to a difference in pressure between the reducer tank and the pump body, fluid flows into the pump. In the suction stroke, fluid does not flow out of the pump, and the reducer boosting pressure is maintained by the hydraulic BUFFER. After pump control is set to Mode 0, a suction stroke execution status is checked in a step 236. If the suction stroke is complete, then before the routine ends pump control resets stroke activation suction stroke and sets compression stroke activation to initiate a compression stroke in the next cycle. Otherwise, the suction stroke time is examined in a step 231, and if it is too long then a failure is reported in a step 232 and the routine ends. Referring again to the suction stroke activation state examination, if a suction stroke is not activated then a compression stroke activation state is checked. If a compression stroke is not activated, then the suction stroke activation is established and pressure control is disabled before the routine ends, otherwise, in a step 235, the pressure control is enabled to maintain pressure. of hydraulic BUFFER at a constant level commanded by the DCU. A compression stroke execution status is examined in a step 237 after step 235. If the compression stroke is not completed, then the routine ends. Otherwise, the compression stroke activation is reset and the suction stroke activation is established. Pressure control is then disabled and the Mode 1 time in pump control is examined in a step 233. A fault is reported in a step 234 if the Mode 1 time is too short.
    [042] According to the ideal gas law, the hydraulic BUFFER pressure is determined by the amount of compressed air trapped in the pump body at a given temperature and volume, and therefore this pressure can be controlled by adjusting the amount of air compressed with solenoid valves 201 and 203. One embodiment of the pressure control mentioned in step 235 of Figure 2b is a service routine running periodically for a timer-based interruption, as shown in Figure 2c. In this routine, a pressure control state is checked first. If pressure control is not enabled, then all three timer modes, Timer_Mode0, Timer_Mode1 and Timer_Mode3 are cleared and the routine ends. Otherwise, the pressure detection value obtained from sensor 219 (Fig. 2a) is examined. If the pressure value is above a Th1 threshold and below another Th2 threshold, the controller switches to Mode 1, in which compressed air is held inside the pump housing, and the Timer_Mode1 of timer is incremented. If the pressure is greater than the Th2 threshold, then the controller goes to Mode 0 to release air and increment the timer's Timer_Mode0, and if the pressure drops below the Th1 threshold the controller switches to Mode 3 to supply air in pump to increase air pressure and increment Mode 3 of Timer_Mode3 timer. As mentioned earlier, Mode 2 must not be allowed in pressure control. To maintain pump control momentarily going to Mode 2, when switching from Mode 3 to Mode 0, the controller must de-energize solenoid valve 201 first, while when changing modes back to Mode 3 from Mode 0 the controller must energize solenoid valve 203 first.
    [043] In the pump control of figure 2b, a refill event and a pump full event can be used, respectively, when initiating a suction stroke and a compression stroke in steps 236 and 237. A refill event is activated when detecting reducer level in pump body or using injection time to calculate reducer level. To detect reducer level in the pump, a level sensor needs to be installed inside the pump (not shown in figure 2a), although the amount of accumulated flow, which is calculated using injection time and pressure or mass flow rate, can be used to determine the reducer level in the pump housing. Similar to the refill event, the pump full event can be activated by detecting reducer level or calculating refill time, which is a function of the reducer level in the tank, and the pressure difference between the reducer in the pump housing and the one in the reducer tank. Since on a suction stroke, reducer boosting pressure is only supplied by the hydraulic BUFFER and not controlled, suction stroke time must be kept small so as not to cause significant pressure drop. When a level sensor is used in refill enable and pump full events, if the reductant tank is empty then a pump full event will not activate for a long time resulting in a long suction stroke. Therefore, upon detecting a failed pump full event, an empty liquid tank can be detected. Steps 231 and 232 in Figure 2b show this detection. After a compression stroke is activated, if it is difficult to establish the actuating pressure, then there may be a pump problem, eg leaking, or a compressed air problem. In this way, excessively long Mode 1 time on a compression stroke can be used to detect these failures. Steps 233 and 234 in Figure 2b show this detection.
    [044] When a motor is shut down, reducer in pump body, hydraulic BUFFER and lines must be drained to prevent leakage or freezing. In the dosing system shown in figure 1 and figure 2a, draining of the reducer can be performed by using shut-off valve 137 in Mode 1 of the pressure control; for example, when the shutoff valve 137 is opened, reducer in the pump body, hydraulic BUFFER and in the lines is pressed back into the reducer tank by the compressed air inside the pump body through line 131 and line 125. After Purging, compressed air trapped inside the pump housing in Mode 1 is released to the reductant tank. The purge process may not be able to drain all the residue trapped in the injector 130. To further clean the injector, a Mode 3 can be activated while the shutoff valve 137 is closed and the injector nozzle is energized to blow out the residue in the gun 130.
    [045] Boost pressure in the air driven hydraulic pumping system shown in figure 2a can only be controlled below that of the compressed air supply. In a gearbox delivery system, however, a high boost pressure is required for good atomization, which is important to obtain high conversion efficiency and avoid collision and droplet deposition. To raise thrust pressure so that we can use a low pressure compressed air supply, a pump with a piston inside as shown in Figure 3a can be used. Referring to Figure 3a, within a pump housing 300, a piston 302 has a large diameter surface 303 contacting compressed air. The other side of piston 302 has a small diameter surface 304 contacting reducer. The piston 302 divides the pump housing 300 into three spaces: a compressed air space 340, an intermediate space 310, which forms an air chamber, and a reducer chamber 330. The compressed air space 340 is sealed off from the space. intermediate 310 by an O-ring 301 on piston 302, while reducer chamber 330 is sealed from intermediate space 310 using a seal 321 in bore 320. A spring 305 is used to support piston 302. When pressure Pc is applied to compressed air space 340, with the force delivered by piston 302, the thrust pressure obtained in reducer chamber 330 is Pl, ePl = (Pc * A303 - ks * x - f0)/A304 (1), where A303 is a large diameter surface area 303, ks is the spring constant of the spring 305, x is the distance from the highest position of the piston 302 to the current position, f0 is the friction force plus the static spring force, and A304 is the surface area of small diameter 304. According to equation (1), if the spring constant ks and attrition force if they are small, the ratio between the areas 303 and 304, A303/A304, determines the thrust pressure.
    [046] In a compression stroke, when compressed air builds up pressure in space 340, the piston goes down under pressure, depressing the spring and generating thrust pressure in reducer chamber 330. In a suction stroke, when air compressed is released, the piston goes upward under the force provided by spring 305. In this way the reducer is pulled into chamber 330 from the tank. Compared to the pump shown in figure 2a, in the pump in figure 3a, the suction stroke has a forced suction process.
    [047] The controls for the pump in figure 3a are the same as those for the pump in figure 2a. However, the boost pressure control range is different. For the pump in figure 2a, the boost pressure control range is from the opening pressure of the check valve 205, Pb205, to the compressed air pressure Pc, while for the pump in figure 3a, according to the equation ( 1), the boost pressure range is from Pb205 to Pl(0), ePl(0) = (Pc * A303 - f0)/A304.
    [048] In addition to pumping reducer, the pump in figure 3a is also capable of purging reducer residue after a dosing process is completed. Referring to Figure 3a, in the pump, the air chamber has a port 311 fluidly connected to a port 313 in the reducer chamber by means of a line 312, and a check valve 314 prevents the reducer from flowing back to the air chamber. The air chamber also has another port 315 to release trapped compressed air into the room. Ports 311 and 315 are fluidly connected to space 310 except when piston 302 is moved to its lowest position as shown in Figure 3b. In the lowest position, port 311 is fluidly connected to space 340. During normal operations, the pressure within reducer chamber 330 is always greater than that in space 310. Therefore, blocked by check valve 314, there is no flow in line 312. When dosing is complete, shut-off valve 137 (figure 1) is opened, and the DCU stops activating the suction stroke to refill the pump. Once the reducer in the pump is exhausted, the piston 302 moves to its lowest position, connecting compressed air to port 313 through port 311 and line 312. When the reducer in the hydraulic BUFFER is exhausted, under compressed air pressure , reducer residue in the pump and in the hydraulic BUFFER will be pressed back into the tank through line 125 (figure 1). After the purge process, a Mode 3 can be activated while shut-off valve 137 (figure 1) is closed and the injector nozzle is energized to blow out the residue in injector 130 (figure 1). Reducer Tank
    [049] After purging, the compressed air in the pump and hydraulic BUFFER is released, and the hydraulic BUFFER is empty. However, the reducer in the tank will enter the pump body under gravity and pressure difference, although the hydraulic BUFFER and reducer lines are still empty. Consequently, as shown in figure 1, the pump needs a heating device (113) to defrost the gearbox and maintain its temperature above freezing point in cold ambient conditions. The heating apparatus can be eliminated if the pump is positioned inside the reducer tank as shown in figure 4. Referring to figure 4, the tank body 200 is enclosed by a reducer tank 400 with the output line of reducer 207 connected to the hydraulic BUFFER through a port 401 and the compressed air port 202 connected to connector T 220 through a port 402. A refrigerant heater 405 with inlet 127 and outlet 128 is used to heat the reducer when ambient temperature is low. Along with the refrigerant heater, a 403 level sensor is used to detect the reducer volume inside the tank and a 404 temperature sensor is used to monitor and control the reducer temperature. Reducer level sensor 403 and temperature sensor 404 are connected to DCU 140 via lines 141 and 142 respectively.
    [050] As mentioned above, in the pumping system of figure 2a and figure 3a, once the purging is done, the reducer residues in the pump, hydraulic BUFFER and in the lines are drained back to the tank, and the residue in the injector is blown out, melt control for frozen reducer in line 131 is not required and heater 129 (figure 1) is not required. In the system of Figure 4, once the pump is positioned inside the tank, line 123, heater 124 and heater 113 are eliminated. As a result, in this system, the only heating controls required are a reducer tank heating control and a line maintenance heating control, which is used to prevent line 131 from freezing during dosing. In this way, heating control is greatly simplified. Two-Stage PWM Dosing Control
    [051] Reducer feed rate in the system of figure 1 can be controlled by using a PWM signal to control the open time of injector 130 in one PWM cycle. With PWM control, the mass reducer flow rate is determined by the following equation:
    where to is the PWM time, Pr the pressure in the hydraulic BUFFER, Pc the pressure in the exhaust passage 166. Only the PWM period. CD the discharge coefficient. An is the minimum nozzle area, epa working fluid density. Pressure Pc is a function of volumetric exhaust flow rate and ambient pressure. However. because of the engine back pressure requirement, the pressure Pc is limited to a small value compared to the pressure Pr, which is normally greater than 4 bar (400 kPa). As a result, given a PWM control signal, the mass reducer flow rate is mainly affected by the pressure Pr in the hydraulic BUFFER, which is measured by pressure sensor 219 (figure 2a). Therefore, to make the gearbox dosing accurate, we need to compensate for the pressure variation in the hydraulic BUFFER in the PWM control or eliminate pressure variation.
    [052] A two-stage PWM control as shown in figure 5a can be used to compensate for pressure variation. In this control, via line 143, the signal obtained from the pressure sensor (for example, sensor 219 in figure 2) is sent to a sensor signal processing unit 502 on the DCU 140, where the pressure detection signal Analog is filtered and converted to digital signal. The resulting signal is sent to a PWM 510 control module in a PWM 501 signal controller along with a mass reducer flow rate command. The PWM control module then calculates the values for control parameters of a 520 PWM signal generator. A PWM signal is generated by the 520 PWM signal generator and supplied to a 503 power switch circuit, where the PWM signal is converted to a switching signal actuating the injector solenoid valve 130 (figure 1) through the control line 145.
    [053] PWM signal creation on the 501 PWM signal controller includes two stages. In the first stage, the control parameters for the PWM signal generator 520 are set to generate a first stage PWM signal, which consists of second stage PWM signals created by the PWM signal generator 520 in second stage signal generation. The first stage PWM signal generation has an execution rate matching the pressure sensor response rate, while the frequency of the second stage PWM signal is independent of the first stage PWM signal, and for this reason it can be set high to increase control accuracy.
    [054] One mode of the PWM 510 control module is shown in figure 5b. In this module, upon receiving the mass flow rate command, in blocks 511 and 512, the duty cycle and period of the first stage PWM signal are calculated and provided for a block 514, where a target value is determined. The target value is then compared to a current value calculated in a block 513 with the pressure feedback value provided by the sensor signal processing unit 502 (figure 5a). The resulting error value is used by a 515 block to calculate the set value in time, and the period set value for the second stage PWM signal is determined with the mass flow rate command in a 516 block.
    [055] A variety of circuits can be used in the 520 PWM signal generator to generate a PWM signal. The block diagram and signal flowchart of an exemplary circuit is shown in Figure 5c. In this circuit, period and time values of a PWM signal are set to a period value register 521 and a time value register 522 respectively. Upon the falling edge of an LD signal, the values in the period value register 521 and the time value register 522, respectively, are additionally loaded into a period value counter 523 and a time value counter 524 Both of the period value counter 523 and the time value counter 524 are countdown counters and a clock signal synchronizes their counting actions. When period value counter 523 counts to 0, in load control logic 525, an LD pulse is generated with the clock signal, and a new cycle starts at the falling edge of the LD pulse. The DA period counter value, the LD signal, the DB period register value, the clock signal, the DC time register value and the value counter value at DD times are used in a control logic. signal 526 to generate the PWM signal. In signal control logic 526, if DC is equal to or greater than DB, that is, the value-in-time register setting value is equal to or greater than the period register setting value, then a high level signal or 100% duty cycle PWM signal is generated by a falling edge of the LD signal. When DC is set to 0, then a low level signal ie 0% duty cycle PWM signal is generated on a falling edge of the LD signal. If DC is within 0 and DB, then on a rising edge of the clock signal, the PWM signal is determined by the values of the period value counter and the time value counter, DA and DB: the PWM signal is at high level only when both the DA and DB are greater than 0.
    [056] The PWM 510 control block can be realized with a service routine running periodically for a timer-based interrupt. A flowchart of this interrupt service routine is shown in Figure 5d. In the flowchart, tv and Thd are constant values; P1 is the period value of the first stage PWM signal, and P3 is the break period value. Status is the PWM pulse status signal. When a constant on_time value of tv is set for the second PWM signal, Status value is ON, otherwise it is OFF. The variable target_value contains the target on_time value for the first stage PWM signal, while the variable current_value saves the calculated on_time value of the first stage PWM signal at the current time. P2 and On_time2 are respectively the period and time registers in second stage PWM signal generation, and the Timer variable saves the current time in a first stage PWM cycle.
    [057] When the interrupt routine is activated, the Timer value is compared to the P1 period value of the first stage PWM signal. If the current cycle is finished, ie Timer >= P1, then the on_time value of the second stage PWM signal is examined. When the on_time value is less than tv, the total error of this PWM cycle, ie previous_error, is calculated. And after the Timer value is reset to P3 and the current_value is initialized in a step 532, the P2 register and the target_value variable are updated to a new cycle, which starts with calculating the error to be corrected in the current cycle by adding the current error to the error in the previous cycle. If the error to be corrected is greater than tv, then the on_time of the second PWM signal, On_time2, is set to tv and Status signaling is set, otherwise On_time2 is set to error value and Status signaling is reset . The routine ends then. Referring again to the comparison between the value On_time2 and tv, if the value On_time2 is not less than tv then it means that the error cannot be corrected in this PWM cycle. In this case, the error in the previous cycle is calculated and after the Timer is set to P3 and the current_value is initialized, Status flag is set. Once the error is not corrected, it accumulates. When the accumulated error is greater than the Thd threshold, a fault is reported, and the routine ends. Referring again to the comparison between Timer value and P1, when Timer value is less than P1, ie, in the current PWM cycle, Timer value is incremented by P3, and then Status signaling is examined. If the Status flag is OFF then On_time2 is cleared to 0, and the routine ends, otherwise current_value is calculated in a step 531 and the error is updated thereafter. Before the routine ends, the error value is compared to tv. If the error value is equal to or greater than tv, then On_Time2 is set to tv, otherwise the error value is set to On_time2 and Status flag is reset to OFF. The routine ends then.
    [058] In the interrupt routine, normally tv is selected greater than the error to be corrected (eg tv equals the value of P2). And the interrupt period value (P3) can be equal to that of the second stage PWM signal (P2). With the interrupt routine of figure 5d, a graph of signal synchronization when tv equals P3 and P2 is shown in figure 5e. An interrupt is activated at a time 546. Since the error, which is calculated by comparing the value of current_value and a target value of 547, is greater than tv, On_time2 is set to tv. Upon a falling edge of the LD signal, at a time 541, the value On_time2 is loaded into the value counter in times (for example, 524 in figure 5c) and a PWM pulse is activated. The current_value accumulates over time. At a time 542, when the calculated error is less than tv, the error value is assigned to On_time2. At the next interrupt activated at a time 543, On_time2 is set to 0 and the variable current_value is locked at a value 548. The counter value on_time is then updated on the falling edge of an LD signal at a time 544, and the pulse PWM is complete. At a time 545 the current PWM cycle ends, and the previous_error (figure 5d) is updated to the next cycle by adding the error between the current_value 548 and the target value 547.
    [059] In the interrupt routine of figure 5d, the target_value can be calculated with the gear flow rate command using the following formula: target_value (i) = Mass_flow_rate_cmd * S0 (F1), where Mass_flow_rate_cmd is the rate command mass flow for PWM control, and S0 is the period value of the first stage PWM signal. And the formula to calculate the current_value in step 531 can be: current_value(i) = K * sqrt(Pr(i) - Pc) * P3 + current_value (i-1) (F2), where sqrt is the square root calculation , Pr(i) the pressure detection value for the calculation in the i-th interrupt cycle, and Pc the pressure in the exhaust passage 166; K is the C‘D A'nP2P term in equation (2), and i is the number of interrupts after the Timer is reset:i= Timer/P3 (F3);current_value(0) is set to 0 in step 532.
    [060] Hydraulic BUFFER pressure in the pumping system is kept constant during compression stroke. However, in a suction stroke, the pressure varies as the closed loop pressure control has to be disabled. Two-stage PWM control is a method of accurately controlling the reducer flow rate with pressure variation. Another method is to use a dual pump system as shown in figure 6. Referring to figure 6, the two pumps 610 and 620 and a hydraulic BUFFER 630 work together to provide a pressure-controlled liquid flow. A normally closed air inlet solenoid 601 with its outlet fluidly connected to pump 610 has its inlet fluidly connected to a side port of a T 603 connector via an air passage 602. connector T 603 is fluidly connected to the inlet of another normally closed air inlet solenoid 606, the outlet of which is fluidly connected to pump 620. The center port of the T connector 603 is fluidly connected to an air supply tablet. Likewise, the normally open air release solenoids 605 and 611 of pumps 610 and 620 are fluidly connected together via a T 608 connector, whose center port can be fluidly connected to a muffler 609 to reduce noise of air release. In the reducer delivery path, a passage 613 fluidly connects the reducer supply port of the pump 610 to a side port of a T connector 614, which other side port is fluidly connected to the reducer supply port of the pump. 620 via a port 615. The center port of the T connector 614 is fluidly connected to a reducer supply via port 117. Similarly, the reducer output ports of pumps 610 and 620 are fluidly connected. The central port of the T 618 connector is fluidly connected to the two side ports of a T 618 connector separately via passages 616 and 617. The center port of the T 618 connector is fluidly connected to the reducer supply port of a hydraulic BUFFER 630. of the hydraulic BUFFER 630 is electrically connected to the DCU 140 via port 114 and line 143, and the DCU 140 also electrically controls solenoid valves 601, 605, 606 and 611 via control lines 146. Both b Both 610 and 620 can work alternately to avoid a closed-loop pressure control period of wasted time. Dosage Control
    [061] The dosing control is for delivering reducer to an exhaust gas treatment system. Referring to Figure 7a, with the pumping system of Figure 1, the total dose control has five main states: an Off state 701, a Sleep state 702, a Pre-Activate state 710, a Dosage state 720 and a Purge state 730. In the Off state 701, the pump control is in Mode 0, and injector 130 and return line shutoff valve 137 are de-energized, while in the Idle 702 state with injector 130 and the shutoff valve 137 still being off, the pump control goes to Mode 1, in which air inside the pump body is isolated from the environment.
    [062] In the pre-activation state, there are two substates: a PR1 state in which reducer pressure is established, and a PR2 state to release trapped air in reducer lines and the injector. One modality of pre-activation control is an interrupt service routine with its flowchart shown in figure 7b. This service routine runs periodically for a timer-based interrupt. When the service routine starts, once preactivation control is enabled, the DoserState is examined. If it is neither PR1 nor PR2, then the shutoff valve and injector are de-energized first and then pump control is set to Mode 3, with which compressed air flows into the pump housing. Then the DoserState is set to PR1 and the routine ends thereafter. When the routine is called next time, the DoserState becomes PR1, then the routine examines the pressure in the hydraulic BUFFER, and if it is equal to or less than a Pr_Thd threshold then the routine ends, otherwise the DoserState is set to PR2 , and the pump pressure control as shown in figure 2c is enabled to keep the pump pressure constant. Before the routine ends, shutoff valve 137 is energized to release trapped air back into the tank. When the routine is called with DoserState being set to PR2, then a Timer_PR2 of timer is used to control the opening time of stop valve 137. When the timer value is greater than a threshold PR_Thd2, with the timer value being reset , stop valve 137 is cleared and the DoserState is set to PRIME_COMPLETE. The routine ends then.
    [063] Referring again to figure 7a, in dosing state 720, in addition to pump control, which includes two states: a suction stroke state 721 and a compression stroke state 722, there is another control , dose rate control 703 running in parallel. A stroke control interrupt routine shown in figure 2b with the pressure control routine shown in figure 2c can be used for pump control. And a two-stage PWM feed control routine from figure 5d can be used for feed rate control.
    [064] The purge control state also includes two substates: a PU1 731 state, in which reducer is drained from the pump, hydraulic and lines BUFFER to the tank, and a PU2 732 state, in which reducer residue inside the injector that is not drained in PU1 is blown out. A service routine running periodically for a timer-based interrupt such as shown in Figure 7c can be used for purge control. In this routine, when a purge control is enabled, the DoserState is first examined. If it is neither PU1 nor PU2, then the hydraulic pressure is compared to a threshold value PU_Thd1. If the pressure is greater than the threshold, then with DoserState being set to PU1, pump control is set to Mode 1, whereby the air in the pump body is isolated from both the compressed air supply and the environment, and shut-off valve 137 is energized, otherwise pump control is set to Mode 3, and shut-off valve 137 is de-energized to build up pressure. Injector 130 is de-energized, and the routine ends thereafter. When the routine starts with the DoserState being set to PU1, then the hydraulic BUFFER pressure is examined. If the pressure is equal to or greater than a threshold value PU_Thd2, then the routine ends, otherwise a Timer_PU1 of timer is used to control the opening time of stop valve 137. If the opening time is greater than a threshold PU_Thd4, then with the timer reset, stop valve 137 is cleared. Pump control is then set to Mode 3 and injector 130 is energized to blow the reducer residue out. The routine ends after the DoserState is set to PU2. When the routine is called with DoserState being set to PU2, a timer Timer_PU2 is used to control the injector open time. If the injector open time is greater than a PU_Thd3 threshold, then the injector is de-energized, and pump control is set to Mode 0, at which air in the pump body is released. The timer is then reset, and the routine ends after the DoserState is set to PURGE_COMPLETE.
    [065] Referring again to Figure 7a, dosing control states change with motor switch status or with commands received from a higher level controller, which determines dosing control strategies. The dosing control enters the Idle 702 state from the Off state by means of a key on signal. If a CMD-Preactivation preactivation command is received, dosing control then starts preactivation, otherwise upon a key off signal the dosing control returns to the Off state. After pre-activation is complete, if a CMD-Normal Dosing command is received, then dose control enters dose state 720, in which pressure control, stroke control, and dose rate control are enabled. In preactivation state 710 and dosing state 720, any time a switch off signal or a CMD-idle command is received, the pump control will enter purge state 730 to remove reducer residue in the pump , hydraulic BUFFER, lines and in the gun. After the purge is completed, if there is a CMD-idle command, then the dose control goes to the idle state, otherwise, upon a key off signal, the dose control goes to the Off state.
    [066] In addition to dosing control, the dosing system also needs to heat the gearbox in low temperature ambient conditions to prevent it from freezing. As mentioned earlier, in a dosing system of figure 4, when the pump is positioned inside the tank, the system only needs to control the temperature of the reductant tank and the pass-through line (eg line 131 in figure 1) to prevent it from falling below the reducer freezing point. In tank temperature control, with the temperature sensor (for example, temperature sensor 404 in figure 4) inside the tank, a simple feedback control, such as a relay control, can be used to heat the gearbox, whereas in pass-through line heating control, since reducer melting is not required, only a small current needs to be applied to the heater (eg, line heater 132 in figure 1) to maintain the line temperature above freezing point during dosing. If the pump is positioned outside the tank, then in addition to the tank temperature control and heating control for the through line, extra heating controls are needed to control the pump temperature (eg control the pump temperature using the heater 113 in Figure 1) and the supply line temperature (for example, heating the supply line 123 with the heater 124 in Figure 1). Normally heating for the return line (eg 125 line in figure 1) is not needed. However, if the return line is positioned lower than the reductant tank, then there may be reductant residue in the return line, and an extra heater (eg heater 117 in figure 1) is needed to prevent the temperature from occurring. on the return line is too low. Compressed Air Supply
    [067] The closed-loop control of the hydraulic BUFFER pressure and the two-stage PWM dosing control makes the dosing rate insensitive to pressure variations in the compressed air supply, and the use of a pressure booster pump as shown in figure 3a and in figure 3b it allows low pressure compressed air supply. Thus a variety of compressed air sources can be used for the dosing system in the present invention. A convenient source of compressed air in a diesel engine is compressed intake air generated by a turbo. As shown in figure 8, the exhaust gas produced by engine 100 goes to a turbo 840 through exhaust manifold 101. In the turbo compressor, pure air is compressed and the resulting air flow exchanges thermal energy with refrigerant fluid in a Chiller of Charge Air (CAC) to lower its temperature. Clean compressed air goes to an engine intake manifold directly for applications without Exhaust Gas Recirculation (EGR) devices. For applications using EGR (High Pressure EGR), the exhaust gas line is branched to an EGR 830 device before reaching the 840 turbo. The exhaust gas regulated by the EGR 830 device is then mixed with pure compressed air, and the resulting charge flow goes to the 801 inlet manifold. Low temperature compressed air (typically less than 50 °C) arriving from the CAC can be used as an air source for the dosing system. Referring to Figure 8, an air tank 810 is used as a BUFFER to supply compressed air to the dosing system through a port 811. An inlet port 812 is connected to the compressed air through a check valve 813 and an 814 solenoid valve controlled by the DCU 140 (figure 1) through the 815 control lines. The 814 solenoid valve is used to control the flow of air supplied to the air tank. When the engine control allows fresh air to be drawn in from the load flow, the DCU energizes solenoid 814. Compressed air then flows into air tank 810 if its pressure is greater than that set by check valve 813. Compressed air flow rate can be controlled by the DCU by applying a PWM signal to solenoid 814.
    [068] In the present invention, although compressed air can also be used in mixture with reducer to improve atomization such as in an air-assisted dosing system, this is not necessary since the reducer pressure is kept constant. Because of the nature of air-driven hydraulic pumps, which are then the only component consuming compressed air in the dosing system of the present invention, compared to an air-assisted dosing system, air consumption is low: it is equal to reducer consumption and is typically less than 7 L/hour (10 bars (1,000 kPa)) in most applications. Low air consumption is also an enabler to use pure compressed engine intake air as the air source, since the compressed air needed in the dosing system is only a small fraction of the engine intake air.
    [069] Although the present invention has been represented and described with reference to only a limited number of particular preferred embodiments, as will be understood by those skilled in the art, changes, modifications and equivalences in form and function can be made to the invention without departing. of its essential characteristics. Accordingly, the invention is intended to be limited only in spirit and scope as defined in the appended claims, giving full jurisdiction for equivalences in all respects.
    权利要求:
    Claims (13)
    [0001]
    1. Apparatus for delivering reducers to an internal combustion engine exhaust gas system (100), comprising: a reducer tank (120, 400); a source of compressed air; an air-driven hydraulic pump arrangement ( 200, 300) comprising a reducer inlet port (117) fluidly coupled to said reducer tank by means of a check valve (205), the apparatus being CHARACTERIZED by the fact that the hydraulic pump is driven by air (200 , 300) further comprises an air inlet/outlet port (202) to allow compressed air to pass into and out of the tank, a first valve (201) to control the supply of compressed air to the tank, a second valve ( 203) to control the release of compressed air from the tank and a reducer outlet port (208) to allow the reducer within said air driven hydraulic pump to flow out; an injector (130) to control flow rate of reducer for said exhaust gas system; a hydraulic BUFFER (210) having an inlet port (218) fluidly coupled to said reducer outlet port (208) of said hydraulic pump actuated by air by means of a check valve (217) and having a port of outlet (115) fluidly coupled to said injector (130); a controller (501) configured to control reducer pressure by controlling the flow of air supplied from said source of compressed air to said hydraulic pump driven by air through of said first valve (201), and air flow released through said second valve (203), and configured to control a reducer dosage amount to said exhaust gas system by adjusting the opening time of said injector ( 130).
    [0002]
    2. Apparatus, according to claim 1, CHARACTERIZED by the fact that a volume change means (214) is positioned inside said hydraulic BUFFER (210), adapted to change volume depending on the pressure of the reducer inside the called hydraulic BUFFER.
    [0003]
    Apparatus according to claim 1, characterized in that it further comprises: a fluid passage (125) fluidly coupling said injector (130) to said reducer tank (120) and a control valve (137) controlling fluid flow in said fluid passage.
    [0004]
    4. Apparatus, according to claim 3, CHARACTERIZED by the fact that said controller (501) is additionally configured to drain reducer in said hydraulic pump actuated by air (200) when opening said control valve (137).
    [0005]
    5. Apparatus, according to claim 1, CHARACTERIZED by the fact that said air driven hydraulic pump (200) is positioned inside said reducer tank (400).
    [0006]
    6. Apparatus according to claim 1, CHARACTERIZED by the fact that said source of compressed air includes a turbo (840) of said internal combustion engine (100).
    [0007]
    7. Apparatus according to claim 1, CHARACTERIZED by the fact that said air-driven hydraulic pump (200) comprises: a piston (302) adapted to move up and down within said air-driven hydraulic pump (300), separating its internal space into an upper space (340) fluidly connected to said air inlet/outlet port (202) and a lower space (330) fluidly connected to said reducer inlet port ( 117) and to said reducer output port (208); and a fluid passage (312) fluidly coupling said head space (340) to said head space (330) by means of a check valve (314) when said piston moves to a certain position.
    [0008]
    8. Apparatus according to claim 7, CHARACTERIZED by the fact that said piston (302) additionally creates an intermediate space (310) in said internal space of said air-driven hydraulic pump, and said intermediate space is connected by fluid form to the environment.
    [0009]
    9. Apparatus according to claim 7, CHARACTERIZED by the fact that said piston (302) additionally creates an intermediate space (310) in the internal space of said air-driven hydraulic pump, and said intermediate space is connected in a manner fluid to the environment except when said piston is in said certain position.
    [0010]
    Apparatus according to claim 1, CHARACTERIZED in that the air driven hydraulic pump arrangement comprises: an alternative air driven hydraulic pump (610, 620) having a reducer inlet port (117) fluidly coupled to said reducer tank by means of a check valve, an air inlet port (603) fluidly coupled to said source of compressed air, an air outlet port (608) for releasing compressed air from said hydraulic pump air actuated, and a reducer outlet port (618) to allow the reducer within said air actuated hydraulic pump to flow out.
    [0011]
    11. Apparatus according to claim 10, CHARACTERIZED by the fact that said controller (501) is additionally configured to control said alternative air driven hydraulic pump (610, 620) by switching alternately between a suction stroke and a stroke of compression, in which said alternative air driven hydraulic pump arrangement is adapted to provide a constant reducer pressure.
    [0012]
    12. Apparatus, according to claim 1, CHARACTERIZED by further comprising: a Venturi device (220) with its high pressure inlet fluidly coupled to said source of compressed air and its outlet fluidly coupled to the environment, adapted to create a low pressure in the pump making it easier to refill in a suction stroke.
    [0013]
    13. Method for controlling a fluid dosing system for delivering reducers in an exhaust gas system of an internal combustion engine (100), CHARACTERIZED by the fact that the system comprises the apparatus as defined in claim 10 and including a tank of reducer, a first pump (610) with a first pump suction stroke and a first pump compression stroke, a second pump (620) with a second pump suction stroke and a second pump compression stroke, a Hydraulic BUFFER (630), a pressure sensor adapted to provide a detection value indicative of a fluid pressure in said hydraulic BUFFER, and an injector (130), the method comprising: developing fluid pressure (711) in said hydraulic BUFFER (630) in said first pump compression stroke of said first pump (610); enabling a feedback control to maintain said fluid pressure constant within a predetermined range in said first compression stroke. pumping (722) said first pump with at least said detection value obtained from said pressure sensor, and initiating said second pump suction stroke (721) of said second pump (620) thereafter; enabling a feedback control to maintain said fluid pressure within a predetermined range in said second pump compression stroke of said second pump with at least said detection value obtained from said pressure sensor, and initiating said first stroke pump suction of said first pump thereafter; and controlling (733) fluid delivery amount by adjusting an opening time of said injector (130).
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    同族专利:
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    CN203257620U|2013-10-30|
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    US20140053537A1|2014-02-27|
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    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    JPH0219664A|1988-07-07|1990-01-23|Asei Giken:Kk|Hydraulic pump unit by means of pressure gas|
    CN2166255Y|1993-05-28|1994-05-25|衢州凿岩机厂|Double-directional topping-up pump|
    US5806304A|1993-09-21|1998-09-15|Orbital Engine Company Pty. Limited|Catalytic treatment of engine exhaust gas|
    JPH0913955A|1995-06-27|1997-01-14|Komatsu Ltd|Exhaust gas purifying device for diesel engine|
    CN1096566C|1996-09-14|2002-12-18|付连起|Hydraulic or pneumatic driven pump and air compressor|
    US6273120B1|1998-11-12|2001-08-14|Siemens Aktiengesellschaft|Device for introducing a liquid reducing agent into an exhaust gas purification system|
    DE19750138A1|1997-11-12|1999-05-27|Siemens Ag|Device for introducing a liquid reducing agent into an exhaust gas cleaning system|
    DE19819579C1|1998-04-30|1999-09-30|Siemens Ag|Secondary treatment of exhaust from lean burn diesel engine with SCR catalyst, minimizing pump usage and energy consumption|
    US6293097B1|1999-08-16|2001-09-25|Ford Global Technologies, Inc.|On-board reductant delivery system|
    DE19946902A1|1999-09-30|2001-04-05|Bosch Gmbh Robert|Device for the aftertreatment of exhaust gases from an internal combustion engine|
    DE19947197A1|1999-10-01|2001-04-12|Bosch Gmbh Robert|Device and method for dosing a reducing agent|
    DE60200491T2|2001-03-02|2005-06-09|Haldor Topsoe A/S|SCR NOx emission reduction method and apparatus|
    DE10155675A1|2001-08-18|2003-05-28|Bosch Gmbh Robert|Method and device for storing and dosing a reducing agent|
    DE20119514U1|2001-12-03|2002-02-28|Purem Abgassysteme Gmbh & Co|Reduktionsmitteldosiereinrichtung|
    DE10161132A1|2001-12-12|2003-06-26|Siemens Ag|Diaphragm pump with integrated pressure sensor|
    US20040047747A1|2002-09-06|2004-03-11|Kun-Shan Hsu|Pneumatically driven hydraulic pump|
    US20040093856A1|2002-11-18|2004-05-20|Dingle Philip J. G.|Apparatus and method for reductant dosing of an exhaust|
    US7107759B2|2003-07-11|2006-09-19|Denso Corporation|Apparatus for reducing hydrocarbon emission of internal combustion engine|
    JP2005307769A|2004-04-19|2005-11-04|Hino Motors Ltd|Exhaust emission control device|
    US20050252201A1|2004-05-17|2005-11-17|Lecea Oscar A|Method and apparatus for reducing NOx emissions|
    JP4290114B2|2004-12-07|2009-07-01|日産ディーゼル工業株式会社|Exhaust purification equipment|
    DE102004063071B4|2004-12-28|2021-10-14|Robert Bosch Gmbh|Vehicle with a supply unit|
    AT360137T|2004-12-30|2007-05-15|Grundfos Management As|metering pump|
    JP2007154732A|2005-12-02|2007-06-21|Toyota Motor Corp|Control system of internal combustion engine|
    EP3421744A1|2005-12-22|2019-01-02|Emitec Denmark A/S|A fluid transfer system and method|
    SE529591C2|2006-02-08|2007-09-25|Stt Emtec Ab|injection device|
    CN101158306A|2006-02-10|2008-04-09|张家口百通环保科技有限公司|Internal-combustion engines exhaust gas purifying device and working method thereof|
    CN2864112Y|2006-02-14|2007-01-31|重庆宗申技术开发研究有限公司|Complex air pump|
    US7497077B2|2006-07-26|2009-03-03|Southwest Research Institute|System and method for dispensing an aqueous urea solution into an exhaust gas stream|
    WO2008082492A2|2006-12-22|2008-07-10|Volvo Group North America, Inc.|Method and apparatus for controlling exhaust temperature of a diesel engine|
    FR2911643B1|2007-01-19|2009-03-13|Inergy Automotive Systems Res|METHOD AND SYSTEM FOR MONITORING THE OPERATION OF A PUMP|
    JP4165896B2|2007-02-19|2008-10-15|ボッシュ株式会社|Reducing agent path clogging determination device and reducing agent path clogging determination method|
    JP4407705B2|2007-02-26|2010-02-03|株式会社デンソー|Exhaust purification agent addition amount control device and exhaust purification system|
    EP2014886A1|2007-07-09|2009-01-14|Delphi Technologies, Inc.|Reservoir for a fluid dosing system|
    FR2921107A1|2007-09-14|2009-03-20|Inergy Automotive Systems Res|METHOD AND SYSTEM FOR INJECTING A LIQUID|
    FR2926542A1|2008-01-17|2009-07-24|Inergy Automotive Systems Res|PROCESS FOR THE TRANSFER OF A LIQUID USING A PUMP|
    JP2010053847A|2008-03-19|2010-03-11|Denso Corp|Exhaust emission control system for internal combustion engine|
    CN101660442B|2008-05-28|2011-12-07|中国第一汽车集团公司|Vehicle-mounted SCR metering and ejecting system taking NOx in exhaust gas as variable|
    US20090301064A1|2008-06-05|2009-12-10|Eugen Maier|Urea pump assembly for an exhaust gas treatment system|
    CN101737127B|2008-11-25|2012-01-25|无锡油泵油嘴研究所|SCP urea injection system for post treatment of diesel engine emissions|
    DE102009005790A1|2009-01-22|2010-07-29|Albonair Gmbh|dosing|
    US8555613B2|2009-03-02|2013-10-15|GM Global Technology Operations LLC|Model-based diagnostics of NOx sensor malfunction for selective catalyst reduction system|
    CN201416529Y|2009-05-20|2010-03-03|泰安凯瑞特包装材料有限公司|Pneumatic-hydraulic membrane pump for pharmacy|
    JP5388286B2|2009-06-19|2014-01-15|ボッシュ株式会社|Exhaust purification device and control method thereof|
    EP2454482B1|2009-07-13|2020-05-13|Saint-Gobain Performance Plastics Corporation|Dispensing pump|
    US8783022B2|2009-08-17|2014-07-22|Donaldson Company, Inc.|Retrofit aftertreatment system for treating diesel exhaust|
    FR2949505B1|2009-09-03|2011-09-02|Peugeot Citroen Automobiles Sa|REDUCER INJECTION DEVICE FOR SELECTIVE CATALYTIC REDUCTION AND ASSEMBLY COMPRISING AN ENGINE AND AN EXHAUST LINE PROVIDED WITH SUCH AN INJECTION DEVICE|
    DE102009029188A1|2009-09-03|2011-03-17|Robert Bosch Gmbh|Dosing system for injecting fluid into exhaust tract of internal combustion engine, comprises pumping unit, which is hydraulically connected with fuel injection system|
    JP5534602B2|2009-11-06|2014-07-02|ボッシュ株式会社|Abnormality detection device and abnormality detection method for reducing agent injection valve|
    US20110138787A1|2009-12-15|2011-06-16|Delphi Technologies, Inc.|Liquid reductant dosing reservoir and method for its manufacture|
    CN101806238A|2010-03-13|2010-08-18|中国第一汽车集团公司|Air-assisted atomized urea reducing agent spraying controlling system of pump power|
    CN201738996U|2010-03-13|2011-02-09|中国第一汽车集团公司|Air-powered atomized urea reductant jetting control system|
    US8393142B2|2010-04-30|2013-03-12|Caterpillar Inc.|Reductant dosing manifold|
    DE102010030058A1|2010-06-15|2011-12-15|Robert Bosch Gmbh|Extensible pumping unit for internal combustion engine of motor car, has reducing agent connected to metering valve, work membranes operating expansion material elements, and pressure chamber accommodated in buffer|
    CN201696246U|2010-06-19|2011-01-05|汕头市通力机械制造有限公司|Pneumatic hydraulic pump|
    CN102116188B|2010-07-21|2013-01-09|苏州派格力减排系统有限公司|Constant-pressure type metering injection system|
    CN102400742B|2010-09-07|2013-12-25|博世汽车柴油系统股份有限公司|Vehicle SCR system and reducing agent supply device thereof|
    US8943808B2|2010-09-27|2015-02-03|Caterpillar Inc.|Reductant dosing system|
    CN102477892B|2010-11-30|2013-09-25|苏州派格丽减排系统有限公司|Automatic calibration system for urea metering jet pumps and calibration method thereof|
    CN202132088U|2011-07-01|2012-02-01|吉林大学|Universal SCR spraying system|
    US8881507B2|2011-08-22|2014-11-11|Mi Yan|Air driven reductant delivery system|
    CN102733913B|2012-07-02|2016-07-20|中国第一汽车股份有限公司|The aftertreatment control unit of two-stage afterheat manner storing and supplying ammonia|US9383406B2|2009-11-30|2016-07-05|Essai, Inc.|Systems and methods for conforming device testers to integrated circuit device with pressure relief valve|
    US8881507B2|2011-08-22|2014-11-11|Mi Yan|Air driven reductant delivery system|
    US9255512B2|2011-08-22|2016-02-09|Cummins Emission Solutions, Inc.|Urea injection systems wash cycles|
    CN105008691B|2013-02-27|2018-01-16|康明斯知识产权公司|For diagnosing the device, method and system of reducing agent transportation performance|
    US20140318630A1|2013-04-24|2014-10-30|Vopak North America, Inc.|Handling Bituminous Crude Oil in Tank Cars|
    US9926822B2|2013-08-16|2018-03-27|Cummins Emission Solutions, Inc.|Air curtain for urea mixing chamber|
    CN103438029A|2013-09-09|2013-12-11|青岛格兰德新能源有限公司|Wind-power-valley-powered pneumatic spring energy storage and circulation type water pumping system|
    CN103511044B|2013-09-30|2015-12-02|天津亿利汽车环保科技有限公司|Scr temperature control system|
    CN103511039A|2013-09-30|2014-01-15|天津亿利汽车环保科技有限公司|Pneumatic type urea injection system|
    DE102013226796B4|2013-12-20|2018-04-05|Continental Automotive Gmbh|A method of testing a temperature sensor in an SCR exhaust aftertreatment system|
    NL2012105C2|2014-01-17|2015-07-20|Aqua Safe B V|METHOD FOR PUMPING A LIQUID, A PUMP DEVICE AND AN INSTALLATION|
    US9140166B1|2014-04-04|2015-09-22|Caterpillar Inc.|Reductant dosing system|
    CN103993936A|2014-05-19|2014-08-20|西南交通大学|Air pressure type urea metering spraying system easy to control|
    CN104005819A|2014-05-19|2014-08-27|西南交通大学|Air pressure type urea metering injection system with two urea pressure containers|
    CN104033348B|2014-06-09|2016-09-21|四川大学|The continuous topping-up pump of digital quantitative|
    SE539369C2|2014-06-12|2017-08-15|Scania Cv Ab|System and method for transferring and evacuating fluid from the secondary tank to a main tank in a vehicle|
    US20140326325A1|2014-07-21|2014-11-06|Caterpillar Inc.|System and method for filling reductant tank|
    CN105890971B|2014-10-09|2019-08-23|中国科学院地质与地球物理研究所|The continuous servo liquid feed device of rock fracture seepage flow|
    US9845717B2|2014-10-28|2017-12-19|Ford Global Technologies, Llc|Systems and methods for managing diesel exhaust fluid stratification|
    US9512763B2|2014-12-05|2016-12-06|Caterpillar Inc.|Diesel exhaust fluid dosing system for diesel engine aftertreatment module|
    US10513960B2|2014-12-25|2019-12-24|Volvo Truck Corporation|Exhaust purification device for engine|
    CN104742891B|2015-03-05|2017-09-29|郑州宇通客车股份有限公司|Proportion adjustable valve gear and brake control method based on switch electromagnetic valve|
    CN107250499B|2015-03-06|2019-12-13|康明斯排放处理公司|System and method for purging an exhaust reductant delivery system|
    GB2537598B|2015-04-13|2017-09-13|Perkins Engines Co Ltd|Method of controlling an engine system|
    US10260394B2|2015-05-01|2019-04-16|Cummins Emission Solutions Inc.|Automatic performance tuning for diesel exhaust fluid dosing unit|
    US9670818B2|2015-08-07|2017-06-06|Caterpillar Inc.|Air-assist dosing system having priming detection|
    US9850832B2|2015-09-21|2017-12-26|Ford Global Technologies, Llc|System and methods for preventing hydrocarbon breakthrough emissions|
    US9664084B2|2015-09-22|2017-05-30|Caterpillar Inc.|Emission reduction system|
    US10087806B2|2016-02-18|2018-10-02|Cummins Emission Solutions Inc.|Self-tuning circuit for controlling input pressure values for an aftertreatment system|
    JP6373291B2|2016-03-02|2018-08-15|日立建機株式会社|Construction machinery|
    CN106050369B|2016-06-12|2019-03-08|山东康钧环保科技有限公司|A kind of SCR aftertreatment system urea supply device and processing method|
    US10273848B2|2016-09-14|2019-04-30|Caterpillar Inc.|Reductant delivery system|
    CN106438322B|2016-10-10|2017-09-29|长春市科意试验仪器有限公司|A kind of double core flooding pumping discharge opeing control systems tested based on rock indoor|
    EP3333387B1|2016-12-12|2021-03-24|Perkins Engines Company Limited|Injector deposit detection for scr injection system|
    DE102017203878A1|2017-03-09|2018-09-13|Robert Bosch Gmbh|A method of purging a dosing module for injecting a liquid into an exhaust stream of an internal combustion engine of a road vehicle|
    CN109386629B|2017-08-04|2020-01-10|惠州市唐群座椅科技股份有限公司|Charging and discharging valve seat with adjustable flow|
    IT201700094931A1|2017-08-22|2019-02-22|Hutchinson Srl|CONNECTOR FOR A DUCT FOR A HEATING FLUID, IN PARTICULAR OF A SCR SYSTEM OR A WATER INJECTION SYSTEM|
    US20190078570A1|2017-09-14|2019-03-14|Milton Roy, Llc|Automatic Initiation of Priming Sequence for Metering Pumps|
    US10415450B2|2017-10-31|2019-09-17|Cummins Emission Solutions Inc.|Systems and methods for reductant dosing including on-time correction for switching delays|
    CN108036504A|2017-12-01|2018-05-15|苏州印丝特纺织数码科技有限公司|A kind of efficient hot-air heating installation|
    CN108104917A|2017-12-31|2018-06-01|中船动力研究院有限公司|A kind of Urea-SCR spraying systems|
    US10570797B2|2018-01-05|2020-02-25|Cnh Industrial America Llc|Exhaust after-treatment system with improved DEF purge cycling in agricultural vehicles|
    CN111828148B|2019-04-15|2021-10-26|康明斯排放处理公司|System and method for detecting incomplete purge events|
    WO2020248141A1|2019-06-11|2020-12-17|海安县石油科研仪器有限公司|Circulating constant-flow constant-pressure metering pump device|
    WO2021016120A1|2019-07-19|2021-01-28|Chemoil Corporation|Automated diesel exhaust fluidsystem and method|
    CN110552769B|2019-09-18|2021-07-30|山推工程机械股份有限公司|Control method of tail gas aftertreatment system and tail gas aftertreatment system|
    CN110645071B|2019-09-23|2020-11-03|南京科益环保科技有限公司|External hydrocarbon injection device|
    CN111622829A|2020-05-26|2020-09-04|宁波楷世环保科技有限公司|Injection rate control system of ammonia gas generation metering injection device|
    CN111577430A|2020-05-26|2020-08-25|宁波楷世环保科技有限公司|Ammonia gas generation metering injection device with short response time and injection rate control system|
    CN111622828A|2020-05-26|2020-09-04|宁波楷世环保科技有限公司|Ammonia gas generation metering injection device|
    法律状态:
    2018-11-21| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|
    2020-03-17| B06U| Preliminary requirement: requests with searches performed by other patent offices: procedure suspended [chapter 6.21 patent gazette]|
    2021-05-11| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|
    2021-06-01| B16A| Patent or certificate of addition of invention granted|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 17/08/2013, OBSERVADAS AS CONDICOES LEGAIS. |
    优先权:
    申请号 | 申请日 | 专利标题
    US13/592,091|US8881507B2|2011-08-22|2012-08-22|Air driven reductant delivery system|
    US13/592.091|2012-08-22|
    PCT/CN2013/081709|WO2014029301A1|2012-08-22|2013-08-17|Air driven reductant delivery system|
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