• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The present invention relates to a fuel system (4) for an internal combustion engine (2), the fuel system (4) comprising a first fuel pump (16) in fluid connection with a main fuel tank (10) and being arranged to feed fuel from the main fuel tank (10) to a high pressure system (19) arranged to inject fuel to the internal combustion engine (2), and a first fuel filter (18) which is arranged to filter particles and water from the fuel before the fuel enters the high pressure system (19). At least a first sensor (22) for measuring conductivity of the fuel is arranged downstream of the first fuel filter (18) and upstream of the high pressure system (19) to indicate a water content of the fuel after filtration. In this way it is possible to get an indication of too high water content and insufficient filtration capacity of the first fuel filter (18). The invention also relates to an internal combustion engine (2) with such a fuel system, a vehicle (1) with such internal combustion engine (2) and a method to reduce the risk of operational disturbances caused by excess of water in a fuel in the fuel system.Fig. 1
    公开号:SE1550187A1
    申请号:SE1550187
    申请日:2015-02-19
    公开日:2016-08-20
    发明作者:Lind Christoffer；Jonsson Anders
    申请人:Scania Cv Ab；
    IPC主号:
    专利说明:

    1Fuel system for an internal combustion engineTECHNICAL FIELDThe present invention relates to a fuel system for an internal combustion engine and to ainternal combustion engine with such a fuel system, a vehicle with such internal combustionengine and a method to reduce the risk of operational disturbances caused by excess of waterin a fuel.
    BACKGROUND ARTAn internal combustion engine, such as a piston engine, which is driven by diesel or petrol, isequipped with a fuel system to transport fuel from one or several fuel tanks to the internalcombustion engine's injection system. The fuel system comprises one or several fuel pumpswhich may be driven mechanically by the internal combustion engine or be driven by anelectrical engine. The fuel pumps create a fuel flow and pressure to transport the fuel to anaccumulator which may be in the form of a so-called common rail, and further to the internalcombustion engine's injection system, which supplies the fuel to the internal combustionengine's combustion chamber. Common rail may be excluded, and the fuel system mayinstead comprise another form of an injection system, for example a piezo or a unit injectionsystem. Fuel systems also comprise at least one or more fuel filters for filtration of the fuelbefore it reaches the internal combustion engine's injection system.
    The internal combustion engine and its injection system are sensitive to contaminations andmay be negatively affected if the fuel contains a large amount of contaminations.Contaminations may relate to solid particles, gas or liquid. Even if the fuel only comprises asmall amount of contaminations, the consequence may be that the internal combustionengine may not be driven satisfactorily by the fuel. Further, an excessive amount of water maycause undesired wear and corrosion of components in fuel systems. Fuel systems thereforecomprise a fuel filter, which both filters away particles and separates water occurring in thefuel. ln today's fuel systems, water separation is a requirement in the low pressure circuit inconnection with filtration to enable disturbance free function of for example fuel pumps.2For example WO 2012/023638 A1 shows a device to protect an engine against inflow of waterby dropping the engine RPM if water drain does not occur. Water drain is detected by meansof a water-in-fuel (W|F)-sensor adapted to detect whether water drain occurs or not, thesensor being installed in a water separator. However, the disclosed system is directed todetect if water drain occurs but does not indicate how well the water drain functions orwhether the fuel fed to the fuel system actually contains water or not.
    Thus, despite prior art solutions in the area, there is a need to further develop a fuel system,which reduces the risk of complications and operational disturbances due to insufficient waterseparation.
    SUMMARY OF THE INVENTIONThe requirements are increasing both in relation to long service intervals of fuel filters andhigh efficiency of water separation, but it has been difficult to fulfil both of theserequirements. Today, it is common to drive a vehicle until the fuel filter is clogged or nearlyclogged, at which point the water separation has long been at an unacceptable level due tothe degradation of the filter. This entails driving with aqueous fuel in the injection system,which may cause damages as a consequence. Thus, there is a need for more accurate systemsto detect and indicate to the driver whether the fuel in the fuel system contains water or not.
    The object of the present invention is thus to improve the current fuel systems by obtaining anearlier indication of the fuel filter's function in respect of water separation.lt is also an object of the present invention to improve the current fuel systems by obtainingan indication ofthe actual water content of a fuel to be fed into a fuel system and whether thecontent is acceptable or not.
    Another object of the invention is to achieve a fuel system for an internal combustion engine,which reduces the risk of disturbances in fuel systems due to high water content in fuel.
    These objectives are achieved with a fuel system of the present invention defined in theappended claims. Especially, the present invention relates to a fuel system for an internalcombustion engine, the fuel system comprising a first fuel pump in fluid connection with amain fuel tank and being arranged to feed fuel from the main fuel tank to a high pressure3system, which is arranged to inject fuel to the internal combustion engine. The system furthercomprises a first fuel filter which is arranged to filter particles and water from the fuel beforethe fuel enters the high pressure system. At least a first sensor for measuring conductivity ofthe fuel is arranged downstream of the first fuel filter and upstream of the high pressuresystem to indicate a water content of the fuel after filtration. By using a conductivity sensor, asimple control of the water content can be provided since the conductivity of the fuelincreases with increased water content.
    Preferably, a second sensor for measuring conductivity of the fuel is arranged upstream of thefirst fuel filter to indicate a water content of the fuel before filtration. ln this way it will bepossible to compare the measured conductivity values and get an indication of theperformance of the fuel filter.
    The fuel system may comprise two or more fuel filters. The first sensor for measuring theconductivity of the fuel is arranged downstream of the first fuel filter and upstream of asecond fuel filter. This makes it possible to detect water early in the fuel system, before thewater-containing fuel will be in contact with many components in the fuel system.ln one embodiment of the invention, the values measured for the conductivity can besubmitted to a control device for further analysis. Thus, the first sensor preferably comprises,or the first and second sensors comprise, means arranged to generate a measuring signalcomprising data relating to a measured conductivity value. Also, the first sensor may be, or thefirst and second sensors may be, connected to a control device, wherein the control devicecomprises means for receiving the measuring signal from each of the first sensor and/orsecond sensor, respectively. ln this way, it is possible for the control device to use theinformation from the measurements and thus make calculations usable for control of the fuelsystem and/or the vehicle.
    According to one embodiment, the control device comprises means arranged to compare thereceived measuring signal from the first sensor with a predetermined conductivity value andcreate an error code if the measured conductivity value exceeds the predetermined value. lnthis way the operator of the vehicle may be warned in case of malfunction of the fuel filter.
    Also, it is possible to store an error code for example in the control device of the vehicle. ln4this way the error code will be detected by personnel at service of the vehicle. The fuel filtercan then be replaced before the water filtration grade has become too low.
    According to another embodiment, the fuel system comprises a second sensor for measuringconductivity of the fuel arranged upstream of the first fuel filter to indicate a water content ofthe fuel before filtration, and wherein the control device comprises means arranged tocalculate a water filtration grade of the first fuel filter from the received measuring signal fromthe first sensor and the received measuring signal from the second sensor and to compare thecalculated water filtration grade with a predetermined value for water filtration grade andcreate an error code if the calculated water filtration grade is lower than the predeterminedwater filtration grade. ln this way a relative performance of the first fuel filter may bedetected, i.e. it can be seen if the reduction of water content in the fuel is achieved throughfiltration.
    The control device may be arranged to control the performance of the first fuel pump,wherein the performance is arranged to be dependent on the measured conductivity valueand/or the measured water filtration grade. ln this way, the operator of the vehicle can beforced to take the vehicle to service and change the fuel filter.
    The control device may be adapted to receive the measuring signals continuously. lt is alsopossible that the control device is adapted to receive the measuring signals periodically, i.e.for example at certain intervals or in case of manually controlled random intervals. Anexample of a random interval is for example at start of the vehicle or for example after fillingof fuel.
    Preferably, the first sensor and/or second sensor are connected to the control unit via acommunication bus. Thus, the conductivity measurements may be made a part of the totalcontrol system of the vehicle.
    The invention also relates to an internal combustion engine comprising the fuel system asdefined above. Further, the invention relates to a vehicle comprising the internal combustionengine as defined above.
    Also, the present invention relates to a method to detect the conductivity ofthe fuel and thusget an indication of the water content of the fuel. Therefore, the method reduces the risk for5operational disturbances caused by excessive water content in fuel. Thus, the presentinvention relates to a method to reduce the risk for operational disturbances caused byexcessive water content in fuel in a fuel system for an internal combustion engine, which fuelsystem comprises a first fuel pump in fluid connection with a main fuel tank containing fuel,the first fuel pump being arranged to feed fuel from the fuel tank to a high pressure system,the high pressure system being arranged to inject fuel to an internal combustion engine, and afirst fuel filter being arranged to filter particles and water from the fuel before the fuel is fedto the high pressure system. The method comprises the steps of:to carry out conductivity measurement of the fuel downstream of the first fuel filter bymeans of a first sensor;to generate a measuring signal comprising a measured conductivity value to indicate awater content of the fuel downstream of the first fuel filter.
    The method may further comprise a step of:C.to carry out conductivity measurements additionally with a second sensor upstream ofthe first fuel filter and to generate a measuring signal comprising measuredconductivity values to indicate a water content of the fuel upstream of the first fuelfilter.
    Additionally the method may further comprise steps of:d.to communicate the measuring signal or signals to a control device comprising aprocessing unit, andto compare the measuring signal from the first sensor, or the measuring signals fromthe first and the second sensors with predetermined conductivity values stored in amemory unit of the processing unit, and/orto compare the received measuring signals from the first sensor with the receivedmeasuring signals from the second sensor to indicate a measured water filtration gradeof the first fuel filter and compare the measured water filtration grade with apredetermined water filtration grade stored in a memory unit of the processing unit.
    Preferably, the method further comprises steps of:6g. to create an error code if the measured conductivity values exceed the predeterminedvalues, and/orh. to create an error code if the measured water filtration grade is lower than thepredetermined water filtration grade.
    The present invention also relates to a computer program comprising a program code which,when the program code is executed in a computer, achieves that said computer carries outthe method as defined above. Further, according to the present invention a computerprogram product comprising a data storage medium which is readable by a computer isachieved, the computer program code of a computer program according to above beingstored on the data storage medium.
    The invention and the advantages thereof will be further defined in the following detaileddescription with reference to the appended drawings.BRIEF DESCRIPTION OF THE DRAWINGSFig. 1 shows a schematic side view of a vehicle, comprising a fuel system for an internalcombustion engine according to the present invention,Fig. 2 shows a coupling diagram for a fuel system according to a first embodiment of thepresent invention,Fig. 3 shows a coupling diagram for a fuel system according to a second embodiment of thepresent invention,Fig. 4 shows a coupling diagram for a fuel system according to a third embodiment of thepresent invention,Fig. 5 shows a flow chart of a method according to the present invention, andFig. 6 shows a control device according to the present invention.
    DETAILED DESCRIPTIONIn the fuel systems a fuel pump is arranged in fluid connection with the internal combustionengine and a fuel tank containing fuel. The fuel pump feeds the fuel from the tank to theinternal combustion engine and can be driven mechanically. In this case the fuel pump is7connected to the internal combustion engine and operated by the engine's driving shaft. lnanother type of fuel system for internal combustion engines, the fuel pump is insteadarranged in connection with the fuel tank and pressurises the fuel via fuel pipes to the engine.ln this type of fuel system, the fuel pump is often electrically, pneumatically or hydraulicallydriven, and is operated independently of the internal combustion engine's driving shaft.
    The present invention is suitable for use in connection with both types of fuel pumps and fuelsystems, i.e. where the fuel pump is mechanically driven by the engine's driving shaft and therevolutions thereof and where the fuel pump is arranged in connection with the fuel tank andpushes the fuel to the engine. The fuel pump can be e.g. electrically, pneumatically orhydraulically operated, independently of the internal combustion engine's driving shaft.
    According to one variant, the fuel system may comprise more than one electrically driven fuelpump. For example, the system comprises a first fuel pump arranged to feed fuel from one orseveral main tanks (large tanks) further in the fuel system and suitably to a smaller tank, oftencalled a transfer tank. A second pump can then be arranged downstream of the smaller tankto feed fuel from the smaller tank to the engine, via e.g. a high pressure system including ahigh pressure pump and which is often arranged in connection with the engine. One reasonfor arranging a smaller tank and for feeding the fuel via this tank is that the fuel may gather inlarge tanks when driving in an uneven terrain comprising many hills and valleys, so that thefuel armature (the pipe that sucks up the fuel in the tank) may not be able to suck up the fuelif there is relatively little fuel left in the tank.
    A first fuel filter, which is arranged to filter particles and water from the fuel before the fuelenters the high pressure system, is arranged downstream of the first fuel pump, which isarranged to feed fuel from the one or several main tanks. ln connection with a fuel systemcomprising only one fuel pump, the filter is arranged downstream of this fuel pump. Also inconnection with a fuel system comprising two or more fuel pumps, a fuel filter is arranged atleast downstream of the first fuel pump, which is arranged to feed fuel from the one orseveral main tanks. Alternatively, a fuel filter may be arranged downstream of each pump.
    A fuel filter suitable for use in the present fuel system is preferably a filter which comprises awater-separating layer or a membrane with a water-repelling effect, i.e. a membrane throughwhich the smaller fuel molecules may pass, while the water molecules are stopped. Water8exists in the fuel partly as "free water", which is easily separated from the fuel, and partly asan emulsion in the fuel, which is harder to separate from the fuel since the water is morefinely divided in the emulsion. ln the filter water is separated from the fuel. The fuel filter alsohas a particle collecting layer with the objective of stopping particles in the fuel. The separatedwater is usually collected in a water container in connection with the filter, and contains in therange of 0.05-1.5 litres. Often the container is placed below the filter and the separated watertrickles down into the container due to gravitation. The container is then emptied manually.The water-separating layer or membrane gradually degrades, i.e. the water-repelling effect isimpaired, with the consequence that more and more water molecules pass through themembrane. The fuel system may comprise more than one fuel filter, and preferably each ofthe fuel filters have a capability of separating water.ln Europe and the USA, fuel contains very small amounts of water, in the range of 200 ppm,i.e. 200 x 106 litres per litre of fuel. ln countries with high air humidity, the water content maybe as high as 2-3%, i.e. representing 20,000-30,000 ppm.
    The fuel is pumped with the fuel pump towards and through the fuel filter. ln case the fuelpump is electrically driven, the fuel pump has a controllable pump capacity, i.e. the fuel flowmay be altered depending on an electrical fuel control signal. The fuel flow naturally variesdepending on how much fuel the engine requires, and is normally within the range 0.5-5 litresper minute.
    Conductivity is a measure of the ability of a substance to conduct electricity. By conductivitymeasurements the electrolytes in a solution are measured and thus the ability of the solutionto conduct electric current. The conductivity ofthe fuel increases when water is present in thefuel. Thus, conductivity of the fuel gives an indication of the water content in the fuel.Conductivity may be measured by means of different kinds of conductivity sensors whichdetermine the ionic content of a solution by measuring its conductivity. For example, theconductivity sensor can be a conductivity meter including a probe which is suitable for use inapplications including organic compounds. Conductivity sensors are available on the marketfor example by a company Cole-Parmer®, and the sensor may be adapted to be used within aconductivity range of 0 pS to 200 mS and within a temperature range of -20 to 110°C.9The fuel system of the present invention reduces the risk for water entering the fuel systemand the injection system due to the system comprising means for evaluating the watercontent of the fuel after the filtration. Thus it is possible to indicate an insufficient filtercapacity and warn the operator. The means comprises a first sensor for measuringconductivity of the fuel arranged downstream of the first fuel filter and upstream of the highpressure system to indicate a water content of the fuel after filtration. The conductivity of thefuel correlates with the water content: basically, the more water is present in the fuel thehigher is the conductivity. The invention will now be described more in detail with referenceto the appended drawings.
    Fig. 1 shows a schematic side view of a vehicle 1, which vehicle comprises a fuel system 4 foran internal combustion engine 2 according to the present invention. The internal combustionengine 2 is connected to a gearbox 6, which is further connected to the driving wheels 8 of thevehicle 1 via a transmission. The vehicle also comprises a chassis 10.
    Fig. 2 shows a coupling diagram for a fuel system 4 according to one variant of the presentinvention. The fuel system 4 comprises a first fuel pump 16 in fluid connection with fuel 11 in amain fuel tank 10 via a first fuel conduit 14. The first fuel pump 16 is arranged to feed fuelfrom the main fuel tank 10 to a high pressure system 19 and can be mechanically orelectrically driven. The fuel system may comprise several fuel tanks.
    The fuel system comprises a first fuel filter 18 arranged downstream of the first fuel pump 16arranged to feed fuel from the main tank 10, and upstream of the high pressure system 19,also called an injection system 19. The first fuel filter 18 is arranged downstream of the firstfuel pump 16 and is a fine mesh, water separating filter. At one end ofthe first fuel conduit 14,located in the main fuel tank 10, a coarse mesh sieve 52 is arranged. The coarse mesh sieve 52is thus arranged upstream ofthe first fuel pump 16, entailing that the first fuel pump 16 sucksfuel through the coarse mesh sieve 52. The coarse mesh sieve 52 filters away particles above acertain predetermined size. The first fuel pump 16 then pressurizes the fuel and feeds itthrough the first fuel filter 18, via the first fuel pipe 14, further to the high pressure system 19.The fuel in the fuel tank 10 has thus passed both a coarse mesh sieve 52 and a fine mesh fuelfilter 18, entailing that the high pressure system 19 is protected against water and otherimpurities. By arranging the first fuel filter 18 downstream ofthe first fuel pump 16, the fuel ispressed through the first fuel filter 18, entailing that the fuel passes through the first fuel filter18 more easily, and the risk that the first filter 18 becomes clogged is thus reduced.
    A container 20 for collecting the separated water from the filter is arranged below the firstfuel filter 18. The high pressure system 19 is arranged in the internal combustion engine 2(illustrated in Fig. 1) or in direct connection with the internal combustion engine 2. The highpressure system 19 comprises a plurality of components including a high pressure pump 30,an accumulator 32 in the form of a so-called common rail and an injection device 34 which areshown more in detail in Fig. 4 of the drawings. Alternatively, the common rail may be replacedby another form of an injection device, e.g. a piezo or a unit injection device.
    A first sensor 22 for measuring conductivity is arranged downstream of the first fuel filter 18and upstream of the high pressure system 19. As shown in more detail in Fig. 2, the firstsensor, i.e. a conductivity measurement device, is connected to a communication bus 44, suchas CAN-bus, via a connection 41, and preferably, the CAN-bus 44 communicates with a controldevice 42 of the vehicle. The first sensor 22 is arranged to generate a measuring signalcomprising data relating to a measured conductivity value. The control device 42 comprisesmeans for receiving the measuring signal from the first sensor 22. The control device 42 maycomprise means arranged to compare the received measuring signal from the first sensor 22with a predetermined conductivity value and create an error code if the measuredconductivity value exceeds the predetermined value. ln this way, the operator of the vehiclewill get an indication that the fuel filter needs to be changed.ln another variant of the invention as shown in Fig. 3 it is alternatively or additionally to thefirst variant described in Fig. 2 possible to evaluate the water filtration grade of the first fuelfilter. The system in Fig. 3 corresponds to the system in Fig. 2 except that a second sensor 24for measuring conductivity of the fuel is arranged upstream of the first fuel filter 18 to indicatea water content of the fuel before filtration. The second sensor is also connected to thecommunication bus 44, such as CAN-bus, via a connection 43, and the CAN-bus 44communicates with the control device 42 of the vehicle. ln this embodiment of the invention,the control device 42 comprises means arranged to calculate a water filtration grade of thefirst fuel filter 18 from the received measuring signal from the first sensor 22 and the receivedmeasuring signal from the second sensor 24. Then the control device 42 is arranged to11compare the calculated water filtration grade with a predetermined value for water filtrationgrade and create an error code if the calculated water filtration grade is lower than thepredetermined water filtration grade. ln this way it can be controlled that the water filtrationlevel is acceptable, and a relative value for the water filtration capacity of the fuel filter can beobtained. Thus, the accuracy of the system can be further improved. Therefore, it is possibleto warn the operator of the vehicle that the filter has an insufficient filtering capacity,whereby the operator is advised to change the filter as soon as possible.
    The fuel system may according to one further embodiment ofthe invention comprise two fuelpumps and two fuel filters and an example of such a fuel system 4 is illustrated in Fig. 4. Thefuel system 4 comprises a first fuel pump 16 which is an electrically driven pump by anelectrical motor I/|1 and arranged to feed fuel from a first main fuel tank 10. The systemcomprises also a second fuel tank 12 and a third fuel tank 13 and a second fuel pump 26. Afirst fuel filter 18 is arranged downstream of the first fuel pump 16 and upstream of thesecond fuel pump 26 and the high pressure system 19. A container 20 for collecting theseparated water from the filter is arranged below the first fuel filter 18. A second fuel filter 28is arranged downstream of the second fuel pump 26 and upstream of the high pressuresystem 19. These components may be arranged in the vehicle's chassis 10 (the chassis 10 isshown in Fig.1).
    The third fuel tank 13 is adapted to hold a smaller volume than the fuel tank 10 and thesecond fuel tank 12. The fuel tank 10 and the second fuel tank 12 correspond to main fueltanks and hold substantially the same volume, and have a self-regulating flow between eachother via a connection conduit 54, arranged between the lower part of the fuel tank 10 andthe second fuel tank 12.
    The first fuel pump 16 is arranged between the fuel tank 10 and the third fuel tank 13. Thefirst fuel pump 16 is operated by a first electrical engine I/|1 and its main task is to feed orsupply fuel from the fuel tank 10 to the third fuel tank 13 via a first fuel conduit 14. Thesecond fuel pump 26 is operated by a second electrical engine I/|2 and is arranged inside thethird fuel tank 13, and is thus protected from the environment and cooled by the fuel. Themain task of the second fuel pump 26 is to feed the fuel from the third fuel tank 13 via asecond fuel conduit 40 through the second fuel filter 28 and further to the high pressure12system 19. The fuel is then fed, at a high pressure, to the common rail 32 and further along tothe injection device 34.ln a similar manner as in connection with the embodiments shown in Fig. 2 and 3, a firstsensor 22 for measuring conductivity is arranged downstream of the first fuel filter 18 andupstream ofthe high pressure system 19.
    The first sensor 22, i.e. a conductivity measurement device, is connected to a communicationbus 44, such as CAN-bus, via a connection 41, and preferably, the CAN-bus 44 communicateswith a control device 42 ofthe vehicle. The first sensor 22 is arranged to generate a measuringsignal comprising data relating to the measured conductivity value. The control device 42comprises means for receiving the measuring signal from the first sensor 22. A second sensor24 for measuring conductivity of the fuel is optionally arranged upstream of the first fuel filter18 to indicate a water content of the fuel before filtration. The second sensor is alsoconnected to the communication bus 44, such as CAN-bus, via a connection 43, and the CAN-bus 44 communicates with the control device 42 of the vehicle, and the measurement datacan be handled in a similar manner as explained above in connection with Fig. 2 and 3. Thus,also in this embodiment of the invention, the control device 42 comprises means arranged tocalculate a water filtration grade of the first fuel filter 18 from the received measuring signalfrom the first sensor 22 and the received measuring signal from the second sensor 24. Thenthe control device 42 is arranged to compare the calculated water filtration grade with apredetermined value for the water filtration grade and create an error code if the calculatedwater filtration grade is lower than the predetermined water filtration grade. ln this way it canbe controlled that the water filtration level is acceptable, and a relative value for the waterfiltration capacity of the fuel filter can be obtained. Thus, the accuracy of the system may beimproved. Therefore, it is possible to warn the operator of the vehicle that the filter has aninsufficient filtering capacity, whereby the operator is advised to change the filter as soon aspossible.
    The second fuel pump 26 and the first fuel pump 16 can also be controlled by the controldevice 42 via the CAN bus 44. Thus, the control device 42 can be arranged to control theperformance of the electrical first fuel pump 16 and/or the second fuel pump 26. Thus, theperformance of the first fuel pump 16 and/or the second fuel pump 26 can be arranged to be13dependent on the measured conductivity value and/or the measured water filtration grade.This means that if the fuel has conductivity more than a predetermined value and thuscontains more water than a desired, the pumping rate of the first fuel pump 16 and/or thesecond fuel pump 26 may be arranged to be lower than required by the internal combustionengine 2, whereby the rate of the internal combustion engine needs to be lowered and thefilter changed as soon as possible.lt is possible that the control device 42 is adapted to receive the measuring signalscontinuously. Alternatively, the control device 42 is adapted to receive measuring signalsperiodically at a pre-determined time interval.lt is also possible that additionally the conductivity of the fuel is measured upstream and/ordownstream of the second fuel filter 28 by means of a third and/or a fourth sensor (not shownin the drawings). The sensors function in a similar manner as the first and/or the secondsensors, and in this way it is also possible to collect information about the filtration capacity ofthe additional second fuel filter.
    Fig. 5 shows a flow chart of a method to reduce the risk of operational disturbances caused byexcessive water content in fuel in a fuel system 4 for an internal combustion engine 2. The fuelsystem 4 comprises a first fuel pump 16 in fluid connection with a main fuel tank 10 containingfuel 11, the first fuel pump 16 being arranged to feed fuel from the main fuel tank 10 to a highpressure system 19, the high pressure system 19 being arranged to inject fuel to an internalcombustion engine 2. A first fuel filter 18 is arranged to filter particles and water from the fuelbefore the fuel is fed to the high pressure system. The method comprises the steps of:a. to carry out a conductivity measurement of the fuel downstream of the first fuel filter18 by means of a first sensor;b. to generate a measuring signal comprising a measured conductivity value to indicate awater content of the fuel downstream of the first fuel filter 18.The method further may further comprise a step of:c. to carry out conductivity measurements additionally with a second sensor 24 upstreamof the first fuel filter 18 and to generate a measuring signal comprising measured14conductivity values to indicate a water content of the fuel upstream of the first fuelfilter 18.Further, the method may comprise steps of:d. to communicate the measuring signal or signals to a control device 42 comprising aprocessing unit 120, ande. to compare the measuring signal from the first sensor 22, or the measuring signalsfrom the first and the second sensors 22, 24 with predetermined conductivity valuesstored in a memory unit 121 of the processing unit 120, and/orf. to compare the received measuring signals from the first sensor with the receivedmeasuring signals from the second sensor to indicate a measured water filtration gradeof the first fuel filter 18 and compare the measured water filtration grade with apredetermined water filtration grade stored in a memory unit 121 of the processingunit 120.Further, the method may comprise a step of:g. to create an error code if the measured conductivity values exceed the predeterminedvalues, and/orh. to create an error code if the measured water filtration grade is lower than thepredetermined water filtration grade.
    Overall, the present invention provides a method that reduces the risk for water entering thefuel system. The method of the invention can be arranged to be carried out by any applicablecontrol unit in the vehicle control device, and may e.g. be arranged to be performed by thecontrol device 42. The control device 42 may comprise any relevant control unit 120 in thevehicle control device. The invention can also be implemented by a dedicated controller forconductivity measurement sensors 22, 24.
    Generally the control device 42 comprises or is connected to a CAN bus 44, as shown in Fig. 2-4, comprising one or more communication busses to interconnect a number of electroniccontrol units (ECUs), or controllers, and various components of the vehicle 1. Such a controldevice 42 may comprise a large number of control units. The control device 42 function maybe arranged to receive signals from various sensors in the vehicle and thus control the vehicleaccordingly. Further, the control of the vehicle can be performed by programmed instructions.These programmed instructions typically include a computer program, which when theprogram code is executed in a computer, achieves that said computer carries out the desiredaction such as the method steps ofthe present invention described above.
    The invention further relates to a computer program product comprising a data storagemedium which is readable by a computer, the computer program code of a computer programas described above being stored on the data storage medium. The computer program typicallyforms part of a computer program product. The computer program product comprises anappropriate storage medium with the computer program stored on said storage medium. Thedigital storage medium may e.g. be any of the group: ROM (Read-Only I/|emory), PROM(Programmable Read-Only I/|emory), EPROM (Erasable PROM), Flash memory, EEPROM(Electrically Erasable PROM), hard disk drive, etc., and may be provided in or in connectionwith the control device 42, and wherein the computer program is executed by the controldevice 42. By changing the computer program instructions the vehicle behaviour may thus beadapted to a specific situation.
    An example control device 42 is shown schematically in Fig. 6, the control device 42 can inturn comprise a processing unit 120 which may comprise e.g. any suitable type of processor ormicroprocessor, e.g. a circuit for digital signal processing digital signal processor (DSP), or acircuit with a predetermined specific function (Application Specific Integrated Circuit, ASIC).The processing unit 120 is connected to a memory unit 121 which provides the processing unit120 e.g. the stored program code and / or the stored data the processing unit 120 needs toperform calculations, such as to determine whether an error code is to be activated. Theprocessing unit 120 is also adapted to store interim or final results of the measurementsand/or calculations in the memory unit 121.
    Further, the control unit is equipped with devices 122, 123, 124, 125 for receiving andtransmitting of in- and output signals. These input and output signals may contain measureddata signals as waveforms, pulse, or other attributes, which of the devices 122, 125 forreceiving input signals can be detected as information for the use in the processing device. Thedevices 123, 124 for transmitting output signals are provided to convert the calculation resultsfrom the processing unit 120 to output signals for transmission to other parts of the vehicle16control device 42 and /or the /the components for which the signals are intended. Each ofthe connections to the devices for receiving and transmitting of in- and output signals can beone or more of a cable, a data bus such as a CAN bus (Controller Area Network bus), a I/IOSTbus (Media Oriented Systems Transport), or any other bus configuration, or a wirelessconnection.
    The components and features specified above may within the framework of the invention becombined between different embodiments specified.
    权利要求:
    Claims (1)
    [1] 17CLAll/IS
    1. Fuel system (4) for an internal combustion engine (2), the fuel system (4) comprising a first fuel pump (16) in fluid connection with a main fuel tank (10) and being arranged tofeed fuel from the main fuel tank (10) to a high pressure system (19) arranged to injectfuel to the internal combustion engine (2), and a first fuel filter (18) which is arrangedto filter particles and water from the fuel before the fuel enters the high pressuresystem (19), characterized in that at least a first sensor (22) for measuring conductivityof the fuel is arranged downstream of the first fuel filter (18) and upstream of the highpressure system (19) to indicate a water content of the fuel after filtration. Fuel system (4) according to claim 1, characterized in that a second sensor (24) formeasuring conductivity of the fuel is arranged upstream of the fuel filter (18) toindicate a water content of the fuel before filtration. Fuel system (4) according to claim 1 or 2, characterized in that the fuel system (4)comprises two or more fuel filters (18, 28), and wherein the first sensor (22) formeasuring conductivity of the fuel is arranged downstream of the first fuel filter (18)and upstream of a second fuel filter (28). Fuel system (4) according to any one of claims 1 to 3, characterized in that the firstsensor (22) comprises, or the first and second sensors (22, 24) comprise, meansarranged to generate a measuring signal comprising data relating to a measuredconductivity value. Fuel system (4) according to claim 4, characterized in that the first sensor (22) is, or thefirst and second sensors (22, 24) are, connected to a control device (42), wherein thecontrol device (42) comprises means for receiving the measuring signal from each ofthe first sensor (22) and/or second sensor (24), respectively. Fuel system (4) according to claim 5, characterized in that the control device (42)comprises means arranged to compare the received measuring signal from the firstsensor (22) with a predetermined conductivity value and create an error code if themeasured conductivity value exceeds the predetermined value. Fuel system (4) according to claim 5 or 6, characterized in that the fuel system (4)comprises a second sensor (24) for measuring conductivity of the fuel arranged upstream of the first fuel filter (18) to indicate a water content of the fuel before 10. 11. 12. 13. 14. 18 filtration, and wherein the control device (42) comprises means arranged to calculate awater filtration grade of the first fuel filter (18) from the received measuring signalfrom the first sensor (22) and the received measuring signal from the second sensor(24) and to compare the calculated water filtration grade with a predetermined valuefor water filtration grade and create an error code if the calculated water filtrationgrade is lower than the predetermined water filtration grade. Fuel system (4) according to any one of claims 5 to 7, characterized in that the controldevice (42) is arranged to control the performance of the first fuel pump (16), whereinthe performance is arranged to be dependent on the measured conductivity valueand/or the measured water filtration grade. Fuel system (4) according to any one of claims 5 to 8, characterized in that the controldevice (42) is adapted to receive the measuring signals continuously. Fuel system (4) according to any one of the preceding claims 5 to 9, characterized inthat the first sensor (22) and/or second sensor (24) are connected to the control unit(42) via a communication bus (44). Internal combustion engine (2), characterized in that it comprises the fuel system (4)according to any one ofthe claims 1-10. Vehicle (1), characterized in that it comprises the internal combustion engine (2)according to claim 11. Method to reduce the risk for operational disturbances caused by excessive watercontent in fuel in a fuel system (4) for an internal combustion engine (2), which fuelsystem (4) comprises a first fuel pump (16) in fluid connection with a main fuel tank(10) containing fuel (11), the first fuel pump (16) being arranged to feed fuel from themain fuel tank (10) to a high pressure system (19), the high pressure system (19) beingarranged to inject fuel to an internal combustion engine (2), and a first fuel filter (18)being arranged to filter particles and water from the fuel (11) before the fuel (11) is fedto the high pressure system (19), characterized by the steps of: a. to carry out conductivity measurement of the fuel (11) downstream of the first fuel filter (18) by means of a first sensor (22);b. to generate a measuring signal comprising a measured conductivity value toindicate a water content of the fuel (11) downstream of the first fuel filter (18). Method according to claim 13, wherein the method further comprises a step of: 5 19to carry out conductivity measurements additionally with a second sensor (24)upstream of the first fuel filter (18) and to generate a measuring signal comprisingmeasured conductivity values to indicate a water content of the fuel (11) upstream of the first fuel filter (18).
    15. Method according to claim 13 or 14, wherein the method further comprises steps of: d. to communicate the measuring signal or signals to a control device (42) comprisinga processing unit (120), and to compare the measuring signal from the first sensor (22), or the measuringsignals from the first and the second sensors (22, 24) with predeterminedconductivity values stored in a memory unit (121) of the processing unit (120),and/or to compare the received measuring signals from the first sensor (22) with thereceived measuring signals from the second sensor (24) to indicate a measuredwater filtration grade of the first fuel filter (18) and compare the measured waterfiltration grade with a predetermined water filtration grade stored in a memory unit (121) ofthe processing unit (120).
    16. Method according to claim 15, wherein the method further comprises a step of: g. h. to create an error code if the measured conductivity values exceed thepredetermined values, and/orto create an error code if the measured water filtration grade is lower than the predetermined water filtration grade.
    17. A computer program comprising a program code which, when the program code is executed in a computer, achieves that said computer carries out the method according to any of the claims 14-17.
    18. A computer program product comprising a data storage medium which is readable by a computer, the computer program code of a computer program according to claim 17 being stored on the data storage medium.
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    同族专利:
    公开号 | 公开日
    SE540260C2|2018-05-15|
    DE102016001599A1|2016-08-25|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    JP2013534294A|2010-08-17|2013-09-02|ボルボコンストラクションイクイップメントアーベー|Engine protection device to prevent moisture inflow|
    法律状态:
    2021-09-28| NUG| Patent has lapsed|
    优先权:
    申请号 | 申请日 | 专利标题
    SE1550187A|SE540260C2|2015-02-19|2015-02-19|Fuel system and method for indicating water in fuel by use of a conductivity sensor|SE1550187A| SE540260C2|2015-02-19|2015-02-19|Fuel system and method for indicating water in fuel by use of a conductivity sensor|
    DE102016001599.3A| DE102016001599A1|2015-02-19|2016-02-11|Fuel system for an internal combustion engine|
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