WO2016046297A1

WO2016046297A1 - Fuel supply device for a vehicle operated with liquefied or compressed gas, method for operating a fuel supply device and computer program product

Info

Publication number: WO2016046297A1
Application number: PCT/EP2015/071935
Authority: WO
Inventors: Andreas Heinrich
Original assignee: Continental Automotive Gmbh
Priority date: 2014-09-26
Filing date: 2015-09-24
Publication date: 2016-03-31
Also published as: DE102014219500A1

Abstract

A fuel supply device, for a vehicle (1) operated with liquefied or compressed gas, has an intake path (14) by means of which combustion air is drawn in from the surroundings of the vehicle (1), and a preparation device for preparing the gas upstream of a fuel injection device (4). It also has a heat exchanger (29) for exchanging heat energy between the preparation device and the combustion air drawn in.

Description

description

Fuel supply device for a vehicle operated with liquefied or compressed gas, method for operating a fuel supply device and computer program product

The invention relates to a fuel supply device for a vehicle operated with liquefied or compressed gas and to a method for operating a device for fuel supply and a computer program product.

A compressed gas is understood here and below to mean a gaseous fuel which is stored in the vehicle in a pressure vessel. A liquefied gas is understood here and below as a gaseous fuel under normal conditions, which is liquefied by cooling to low temperatures and / or compression. For example, it is understood to mean natural gas or hydrogen.

From DE 102007036958 AI a fuel supply device for a compressed natural gas (CNG) operated vehicle is known. In this device, a pressure reducing device is provided to reduce the tank pressure of, for example, 250 bar to the lower system pressure of the injector.

With this reduction of the pressure accrued on the pressure Minde ^¬ approximate device cold, which can cause reduction device to a freezing of the pressure. From DE 10 2008 034 581 AI it is known to perform the pressure reducing device in two stages and to use the released at a proportional valve of the second stage heat for heating a mechanical valve of the first stage to prevent icing. An alternative solution, which is already realized in the market ^{¬ be} sensitive systems, is the connection of components of the pressure reducing device to the engine cooling circuit and its heating by engine coolant. However, this typically leads to excessive heating of the components and thus of the fuel and thus to a reduction in efficiency.

Even with liquefied natural gas ("liquefied natural gas", LNG) operated vehicles falls in the preparation of the

Natural gas for burning cold, because the liquid natural gas changes the state of aggregation and becomes gaseous before injection in an evaporator. It is an object of the present invention to provide an apparatus for supplying fuel to a vehicle operated with liquefied or compressed gas, which operates as energy-efficiently as possible. Furthermore, a method suitable for operating the device should be specified.

This object is achieved with the subject matter of the independent claims. Advantageous developments emerge from the dependent claims. According to one embodiment of the invention, a fuel supply device is provided for a vehicle operated with liquefied or compressed gas, which has an intake tract, by means of which combustion air is drawn in from the surroundings of the vehicle, and a treatment device for conditioning the gas upstream of a fuel injection device. Furthermore, the device for supplying fuel has a heat exchange device for exchanging heat energy between the treatment device and the intake combustion air. The processing device has the task of converting the gas taken from a tank container into a form suitable for the injection. This can be, for example, evaporation in an evaporator and / or expansion in a pressure reduction device. In the treatment device falls during operation cold, which would remain unused or even in the case of icing of the pressure reducing device could lead to failure of components. Low temperatures can also damage plastic components and reduce their service life.

The embodiment described has the advantage that the resulting cooling energy is used to cool the intake air. This leads to a higher filling and thus to an increase in the efficiency of the combustion process. At the same time components of the treatment device are heated and thus protected against icing. In LNG vehicles, the heat energy of the intake air is used for the evaporation of the fuel, which causes a further increase in efficiency.

In one embodiment, the heat exchange device is designed to be adjustable. For example, it may be provided to make the heat exchange switched on and off. This has the advantage that the heat exchange can be adapted to the operating conditions of the vehicle. Typically, however, heat exchange will usually be advantageous because the intake air is always an available source of heat and its cooling causes an increase in the efficiency of the combustion process. In one embodiment of the invention, the treatment device is designed as an evaporator for liquefied gas. This embodiment particularly relates to the use of the invention in vehicles powered by liquefied gas, particularly liquid natural gas. In this case, it can be provided as a heat exchange device, an intake air duct, which passes an intake air flow directly to an outside of the evaporator. An intake air flow passing directly by is understood here and below to mean that, during operation, intake air is in direct contact with the outside of the evaporator.

In this embodiment, therefore, the evaporator is at least partially disposed in the intake air flow. This has the advantage that a good heat exchange between the evaporator and the intake air is possible without the need for expensive additional installations.

In one embodiment, a branch line is branched off from the intake air flow in the flow direction after the heat exchange device. This has the advantage that the partial air flow in the branch line can be supplied to a consumer in the vehicle which requires extremely dry air at ^¬ play, a disc drying. Due to the very low temperatures at the evaporator, the sucked air is dried by freezing the water components.

In an alternative embodiment, the treatment plant is designed as a pressure reduction device and has a housing, wherein an expansion region is formed within the housing, is expanded in the compressed gas. This embodiment particularly relates to the use of the invention in vehicles powered by compressed gas, in particular compressed natural gas. This embodiment has the advantage that the released during the treatment of the gas cooling energy is fully implemented in an increase in efficiency of the combustion process: on the one hand by the only warmed up necessary gas, on the other hand by the cooled intake air. A vehicle operated with compressed gas is understood here and below to mean a vehicle in which gas stored in a tank is used as the fuel of an internal combustion engine under pressure, for example under a pressure of 200 or 250 bar.

The pressure reduction device is designed such that it enables the reduction of the tank pressure to the supply pressure of a fuel injection device. Typically, the supply pressure of fuel injectors is 5 to 20 bar. The reduction of the pressure is effected by a controllable expansion, wherein an actuator may be provided for the control. The pressure reduction device can be formed in one or more stages, ie, the expansion can take place in one or more steps. At least at one stage, a heat exchange device is provided according to an embodiment of the invention. If the pressure reduction device has a multi-stage design, then the heat exchange ^{device is} typically provided at least at that stage at which the strongest expansion takes place, that is to say the largest amount of refrigerant is produced. However, it can also be provided at several or at all stages a heat exchange device.

In one embodiment, the heat exchange device is designed as a channel structure in a housing wall of the housing. In this embodiment, the housing has a kind of heat jacket which, for example, surrounds that area of the housing in which the expansion takes place, that is to say the cold is produced. In this area, the housing is supplied with heat by the intake air. This has the advantage that the housing or housed therein components are protected from icing.

In one embodiment of the invention, the heat exchange device is formed by a flow path for compressed gas is formed by the pressure reducing device, wherein intake air in this flow path through the

Pressure reduction device is durchleitbar. In this embodiment, the pressure reduction device is flushable with intake air. This allows a good heat exchange.

In an alternative embodiment, the heat exchange device is formed in that a flow path for intake air is formed on an outer side of the housing. Thus, an intake air line or a part thereof is guided directly past the housing of the pressure reducing device, so that during operation, intake air is in contact with the housing. This has the advantage that a good heat exchange is achieved with little technical effort.

In one embodiment, the processing device further comprises a portion of a supply line from the pressure reduction device to a fuel injection device, wherein the heat exchange device is connected in the portion of the supply line. Accordingly, in this embodiment, the resulting cold is not absorbed directly where it is produced by the expansion, namely at the pressure reducing device, but shortly behind it.

This has the advantage that the heat exchange device can be designed as a se ^¬ parates component and installed as needed in the vehicle. This embodiment may also be advantageous when partially used or the pressure reducing means accumulating refrigerant for a different purpose components of the pressure reducing means to prevent icing for example, be electrically heated, but the accessing of the force ^¬ stoffeinblasvorrichtung gas anyway, is still so cold that a cooling of the Inlet air is advantageously possible. In one embodiment, the heat exchange device is embodied as line loops through which the fuel can flow, wherein an intake air line is designed such that an intake air flow can flow around the line loops. In this embodiment, the heat exchange device is designed in the manner of a cooler. This has the advantage that a large interface for heat exchange is available and the heat transfer is accordingly effective.

In one embodiment, a coolant circuit is provided as the heat exchange device, which discharges cold occurring at the treatment device to the intake combustion air. In this embodiment, a coolant circuit is connected between the treatment device and the intake combustion air, so that the heat transfer takes place in two steps. This has the advantage that more De ^¬ sign freedom is made possible for the processing device and the intake advantage. This embodiment is in particular ^¬ special for use in LNG vehicles.

The term "coolant" is used herein to refer to a heat transfer medium.

According to one aspect of the invention, a vehicle is provided with the described fuel supply device.

The vehicle is a vehicle operated with liquefied or compressed gas, in particular a passenger car, a truck or a bus.

According to a further aspect of the invention, a method for operating the device for supplying fuel is specified, which includes determining at least one parameter as a measure of a cooling time currently available in the conditioning device. energy and the transfer of cooling energy from the Aufberei ^¬ processing device comprises at least into an intake air in dependence on the one determined parameter.

In one embodiment of the method, at least one parameter is a parameter used is selected from the group which includes: an outside temperature, a Tem ^¬ temperature of the conditioning device, an operating temperature of the internal combustion engine of the vehicle, a temperature in the Mo ^¬ goal area, a load requirement the internal combustion engine and a temperature of the fuel. It can be used as parameters and predicted values, such as a soon he ^¬ following high load demand.

These parameters are suitable individually or in combination to identify the available cooling energy as accurately as possible at the treatment facility.

Another aspect of the invention relates to a Computerpro ^¬ program product comprising a computer readable medium and stored on the computer readable medium program code which, when executed on a computing unit, instructs the calculating unit to perform a method according to one of the above embodiments.

The arithmetic unit is designed in particular as an engine control unit.

Embodiments of the invention will now be described with reference to the accompanying figures.

FIG. 1 shows schematically a compressed natural gas

operated vehicle with a Fuel supply device according to an embodiment of the invention;

FIG. 2 schematically shows a sectional view of the housing of the fuel supply device according to FIG

1 and

FIG. 3 shows schematically a liquid natural gas

operated vehicle with a

Device for fuel supply according to a

Embodiment of the invention.

Figure 1 shows a dashed line indicated only vehicle 1, which is designed in particular as a passenger car, truck or bus. The vehicle 1 is operated with compressed natural gas as fuel.

For this purpose, the vehicle 1 has an internal combustion engine 2 with a number of cylinders 3, in which the natural gas is burned. In the embodiment shown, the internal combustion engine 2 has four cylinders 3, but only one of which is shown.

The fuel passes through a Kraftstoffeinblasvorrichtung 4 in the combustion chamber of the cylinder 3, not shown, via an intake manifold 14, combustion air is processed and supplied. Upstream of the Kraftstoffeinblasvorrichtung 4 is a fuel rail 5, the associated ^¬ led from the feed line 10 into the individual fuel Kraftstoffeinblasvor- directions 4 and their associated cylinder 3 distributed.

The fuel injector 4 typically operates at a fuel pressure of about 5-20 bar. This pressure p2 also prevails in the supply line 10. In contrast, the compressed natural gas is formed in a tank 6 formed as a pressure vessel under a Pressure pi of about 200 to 250 bar held. This pressure pi also prevails in the supply line 7, which leads from the tanks 6 via a filter 8 to the processing device designed as a pressure reduction device 9. The pressure reducer 9 reduces the pressure pi to the pressure p2.

To reduce the pressure of the fuel in the pressure reducing device 9 is expanded. He cools down considerably. In the pressure reducing device 9 thus falls during operation to cold, which is discharged via components of the pressure reduction ^¬ device 9. There is a risk that these components will freeze and fail.

In order to prevent this, a heat exchange device 29, not shown in detail in FIG. 1, is provided, in which cold energy arising at the pressure reduction device 9 is released to the combustion air in the intake tract 14.

A possible embodiment of the pressure reduction device 9 with heat exchange device 29 is shown in FIG.

At present, there are various technologies with which the injection of the fuel is implemented. For example, an injection of the fuel into the intake tract 14 or directly into the combustion chamber of the cylinder 3 can take place. The

Pressure reducer 9 according to an embodiment of the invention can be used in conjunction with the various technologies, it is not limited to a particular design of the fuel injector 4. It is also not limited to a specific design of the internal combustion ^¬ machine 2 or a certain number of cylinders 3.

Figure 2 shows the housing 11 of the pressure reducing device 9 in cross section. The housing 11 has an inlet 12 on which Fuel enters at pressure pi. It also has an outlet 13 at which fuel exits at the pressure p2. In front of the inlet 12, an unillustrated shut-off valve is typically provided. In particular, a shut-off valve may be arranged directly on the tank 6, with which the

Fuel supply, for example, when stopping the

Let internal combustion engine 2 or switch off when switching to another type of fuel. The pressure reduction device 9 shown in Figure 2, as an actuator to a controlled by the engine control, not shown piezoelectric actuator 15. The actuator 15 is connected to a valve 16, via which the flow through an opening 17 can be regulated. On the output side of the valve 16, a first chamber 18 is arranged, in which a piston 19 is movably mounted. The piston 19 is arranged in a cylinder 21 and movable against the force of a spring 20.

In the second chamber the pressure p2 is applied. An outlet throttle 23 connects the first chamber 18 with the outlet 13 of the

Pressure reduction device 9. For a control of the piezoelectric actuator 15, the pressures pi and P2 are typically measured by means of pressure sensors. In operation, the piezoelectric actuator 15 displaces the ^closure piece of the valve 16 against the valve seat and thus controls the flow of fuel through the opening 17. A change in this flow causes a change in the pressure prevailing in the first chamber 18 and thus a change in the force on the piston 19. The piston 19 is thereby displaced within the cylinder 21. This allows fuel to flow from the first chamber 18 into the second chamber 22. When the piston 19 is moved downward against the spring force, the pressure p2 in the second chamber 22 increases. Since the first chamber 18 with the outlet 13th is connected via the outlet throttle 23, also flows via the outlet throttle 23 fuel to the outlet 13th

During the expansion of the fuel at the valve 16, in the first chamber 18 and at the outlet throttle 23 is due to the strong cooling of the fuel to cold. In a housing wall 24 of the housing 11, therefore, a heating area 26 is provided with a heat exchange device 29 to which the housing 11 heat is supplied. For this purpose, in the housing wall 24, the channel structure 25 as a heat exchange device 29, flows through the sucked combustion air. The duct structure 25 is thus part of the intake tract 14. In operation, the combustion air releases heat to the housing 11 and thus prevents icing. At the same time, the efficiency of the combustion process is increased by the cooled combustion air.

FIG. 3 schematically shows a liquefied natural gas vehicle 1 with a fuel supply device according to an embodiment of the invention. This vehicle 1 differs from that shown in FIG. 1 in that an evaporator 30 is provided as the treatment device. In the evaporator 30, the liquid natural gas taken from the tanks 6 is converted into the gaseous state and leaves the evaporator 30 at a pressure pi 'of at least 1 bar. In order to achieve the supply pressure p2 'of the fuel injection device 4 of about 5 to 20 bar, a pressure control device 9 ^{λ is} used in this embodiment.

In the evaporation process falls on the evaporator 30 cooling energy, which is used in the embodiment shown to cool the intake combustion air intake air 14. For this purpose, the evaporator 30 is a heat exchanging means ^¬ 29 is not shown in detail, is provided which allows a transfer of heat from the combustion air in the evaporator 30th For regulating the heat exchange device 29, a regulating device, for example a valve 31, is provided. The valve 31 is controllable via a signal line 32 by a computing unit 3, which may be designed in particular as an engine control unit.

The arithmetic unit 33 has a computer-readable medium 35 and a processing unit 34. The processing unit 34 may be designed, for example, as an electronic processor, in particular as a microprocessor or microcontroller. The computer-readable medium 35 can be used, for example, as an EEPROM,

Flash memory or flash EEPROM or NVRAM be formed. On the computer readable medium 35 stores program code is abge ^¬ which, when executed on the computing unit 33, instructs the arithmetic unit 33, the above-mentioned exemplary embodiments of the method execute.

The computing unit 33 is in particular for determining at least one parameter as a measure of a currently available in the United ^¬ evaporator 30 cooling energy and for controlling the valve 31 in dependence on the at least one determined parameter for the transfer of cooling energy from the evaporator 30 into the intake air in Dependent on the at least one determined parameter is formed. As parameters, an outside temperature, a temperature of the evaporator 30, an operating temperature of the internal combustion engine 2 of the vehicle 1, a temperature in the Mo ^¬ goal area, a load requirement of the internal combustion engine 2 and a temperature of the fuel are particularly suitable. To determine at least of a parameter, the arithmetic unit 33 is connected to corresponding sensors, not shown.

In the flow direction after the heat exchange device 29, a branch line 36 is branched off from the intake tract 14 and fed to a consumer in the vehicle 1, which requires particularly dry air, for example a disc drying.

Reference sign list

1 vehicle

2 internal combustion engine

3 cylinders

4 fuel injection orrichtui

5 fuel rail

6 tank

7 supply line

8 filters

9 pressure reducing device

9 ^λ pressure control device

10 supply line

11 housing

12 inlet

13 outlet

14 intake tract

15 piezoelectric actuator

16 valve

17 opening

18 first chamber

19 pistons

20 spring

21 cylinders

22 second chamber

23 drainage aisle

24 housing wall

25 channel structure

26 heating area

28 branch line

29 heat exchanger

30 evaporator

31 valve

32 signal line computer unit

Processing unit computer readable medium branch line

Claims

claims

Fuel supply device for a liquefied or compressed gas powered vehicle (1), comprising:

an intake duct (14), by means of which combustion air from the environment of the vehicle (1) is sucked in;

a treatment device for treating the gas in front of a fuel injection device (4), a heat exchange device (29) for exchanging heat energy between the treatment device and the intake combustion air.

Device according to claim 1,

wherein the heat exchange device (29) is designed to be adjustable.

Apparatus according to claim 1 or 2,

wherein the treatment device is designed as a liquefied gas evaporator (30).

Device according to claim 3,

wherein as a heat exchange device (29) an intake air ^¬ line is provided which passes an intake air flow directly to an outside of the evaporator (30).

Apparatus according to claim 3 or 4,

wherein a branch line (36) is branched off from the intake air flow in the flow direction after the heat exchange device (29).

6. Apparatus according to claim 1 or 2, wherein the treatment plant is designed as Druckminderungsein ^¬ direction (9) and a housing (11), wherein within the housing (11) an expansion region is formed, is expanded in the compressed gas.

7. Apparatus according to claim 6,

wherein the heat exchange device (29) as a channel structure (25) in a housing wall (24) of the housing (11) is formed.

8. Apparatus according to claim 6 or 7,

wherein the heat exchange means (29) is formed by providing a flow path for compressed gas through the pressure reducing means (9) is formed, said intake air flow path by the pressure at this Minde ^¬ approximating means (9) is durchleitbar.

9. Device according to one of claims 6 to 8,

wherein the heat exchange device (29) is formed in that a flow path for intake air on an outside of the housing ^¬ (11) is formed.

10. Apparatus according to claim 8,

wherein the treatment device further comprises a portion of a supply line from the pressure reduction device (9) to a fuel injection device (4), wherein the heat exchange device (29) is connected in the section of the supply line.

11. The device according to claim 10,

wherein the heat exchange means (29) as of the

Fuel-flowable line loops is formed, wherein an intake air pipe is formed such that the line loops can be flowed around by an intake air flow.

Apparatus according to claim 1 or 2,

wherein as a heat exchange device (29), a coolant circuit is provided, which emits at the Aufbereitungsein resulting refrigeration to the sucked combustion ^¬ tion air.

Vehicle (1) with a device for supplying fuel according to one of Claims 1 to 12.

A method of operating a fuel supply apparatus according to any one of claims 1 to 12, comprising:

Determining at least one parameter as a measure of a currently available in the treatment device cooling energy and

Transfer of cooling energy from the treatment ^¬ device in an intake air flow in dependence on the at least one determined parameter.

A computer program product comprising a computer readable medium and stored on the computer readable medium program code which, when executed on a computing unit ^¬, the computing unit instructs to execute a method according to claim fourteenth