EP2139708A2

EP2139708A2 - Heating device and method for supplying fuel to a heating device

Info

Publication number: EP2139708A2
Application number: EP08757967A
Authority: EP
Inventors: Nils Elm; Karsten Köhler
Original assignee: Webasto SE
Current assignee: Webasto SE
Priority date: 2007-05-03
Filing date: 2008-04-22
Publication date: 2010-01-06
Also published as: DE102007020758A1; WO2008135010A2; WO2008135010A3; WO2008135010A9; DE102007020758B4

Abstract

The invention relates to a heating device (10; 100; 200; 300; 400) for a vehicle, comprising a fuel-operated heating unit (30; 130; 230; 330; 430) independent of the engine, wherein the heating unit can be coupled to a fuel supply system of the vehicle such that the heating unit is connected to a vehicle tank (18; 118; 218; 318; 418) via a fuel transfer pump (22; 122; 222; 322; 422) of the fuel supply system. According to a first consideration, a metering and transfer device (28) is provided for feeding and metering fuel to the heating unit (30). According to the invention, according to the first consideration of the invention provision is made for a control device (32) to be provided that is suitable for controlling the metering and transfer device (28) when the fuel transfer pump (22) is turned off or not transferring fuel such that it transfers fuel directly from the vehicle tank (18) via the fuel transfer pump (22) to the heating unit (30) and meters a corresponding fuel feed. According to a second consideration, a valve device (128; 228; 328; 428) for metering a fuel feed to the heating unit is connected downstream of the fuel transfer pump and upstream of the heating unit. According to the invention, according to the second consideration of the invention, provision is made for a control device (32; 132; 232; 332; 432) to be provided that is suitable for controlling the fuel transfer pump for transferring fuel in a park heating mode of the heating unit such that it is operated at a power input that is lower than a power input of the fuel transfer pump operated in an auxiliary heating mode of the heating unit. The invention further relates to a method for supplying fuel to a heating device according to the invention according to the first and second consideration.

Description

Heating device and method for supplying fuel to a heating device

According to a first aspect, the invention relates to a heating device for a vehicle, comprising an engine-independent, fuel-operated heating device which can be coupled to a fuel supply system of the vehicle such that the heating device is connected to a vehicle tank at least via a fuel feed pump of the fuel supply system, and with a metering and conveying device for supplying and metering fuel to the heating device, wherein the metering and conveying device downstream of the fuel feed pump and upstream of the heating device.

In connection with the first aspect, the invention further relates to a method for controlling a fuel supply of a motor-independently operable Heating device of such a heater for a vehicle.

According to a second aspect, the invention relates to a heating device for a vehicle, with a motor-independent, fuel-operated heating device, wherein the heating device with a fuel supply system of the vehicle is coupled such that the heater at least via a fuel feed pump of the fuel supply system with a vehicle tank is connected, wherein a valve device for metering a fuel supply to the heating device downstream of the fuel feed pump and the heater is upstream.

In connection with the second aspect, the invention furthermore relates to a method for controlling / regulating a fuel supply of a motor-independently operable heating device of such a heating device.

A conventional prior art heater is shown, for example, in Figure 1, which is coupleable to a conventional fuel supply system of a vehicle. In this case, the fuel supply system comprises a fuel tank 18 ', which is at least partially filled with fuel and in which a swirl pot 20' is provided in the usual way. A feed line 14 ', via which an internal combustion engine 12' can be supplied with fuel, flows into the swirl pot 20 "For the purpose of supplying fuel to the internal combustion engine 12 ', a fuel feed pump 22' is coupled to the feed line 14 ', which is preferably in the area of the swirl pot 20 ' is arranged. Furthermore, a return line 16 'originating from the internal combustion engine 12' flows into the swirl pot 20 ', via which residual fuel from the internal combustion engine 12' can be returned to the vehicle tank 18 '. In the illustrated case, a heater 10 'is coupled to the fuel supply system of the vehicle. In particular, a heating device 30 'is directly connected via a fuel line 24' to the vehicle tank 18 'or the fuel line 24' opens into the swirl pot 20 ', whereby a fuel supply of the

Heating device 30 'directly from the vehicle tank 18' is made possible. In order to make the fuel supply or fuel delivery to the heater 30 ', a reciprocating metering pump 28' is provided in the fuel line 24 ', which can be controlled by a control device 32' for fuel delivery to the heater 30 '. The control device 32 'is coupled for this purpose for controlling the reciprocating piston metering pump 28' via a control line 34 'with the reciprocating metering pump 28'. The fuel is thus sucked via the reciprocating dosing pump 28 'from the swirl pot 20' mounted in the vehicle tank 18 'or alternatively directly from the vehicle tank 18' via a further fuel line 26 'and to the heating device 30', which is designed, for example, as a combustion heater is, encouraged. In this case, a volume or mass flow of the conveyed fuel to the heating device 30 'is varied by the control device 32' in accordance with the operating conditions of the heating device 30 ', for example via a drive frequency of the reciprocating piston metering pump 28'. However, the heating device 10 'shown in FIG. 1 does not use any of the vehicle's own components, that is to say components which are already used in the vehicle for fuel injection. supply of the internal combustion engine 12 'are located. In the case of the heating device 10 'illustrated in FIG. 1, there is therefore the necessity of mounting the reciprocating piston metering pump 28', a holder of the reciprocating piston metering pump 28 ', the fuel line 24 etc. in addition to the vehicle-specific components or in or on the vehicle to obstruct. Even the material prices of components of the fuel supply system represent a significant proportion of the total costs of a heater application. This proportion is thus further increased when using a heating device, in particular because this known heating device uses a separate fuel supply for the heating device 30 '. Likewise, additional costs arise through the installation of such a heater. Furthermore, some difficulties arise to provide the necessary space for the heater available. In general, the vehicle tank is due to the ever-smaller space also difficult to access, so that the assembly or connection of the heater to the vehicle tank for Brennstoffentnähme is much more difficult. Current vehicle tank design is leading to increasingly dense vehicle tanks to minimize fuel delivery to the vehicle's environment. As a result, access to the vehicle tank and the assembly of components in or on the vehicle tank are becoming increasingly complicated. Furthermore, the vehicle is equipped via the swirl pot arranged in the vehicle tank and a strainer at an inlet of the fuel feed pump with a system which promotes fuel as bubble-free as possible or at least low-bubble to the vehicle engine. However, if the fuel for the heater is taken directly from the vehicle tank, the fuel can be removed during dynamic driving. Swing away movements on a sampling tube or the fuel line, so that air is sucked in. This is at least partially avoided by the fuel from the swirl pot is sucked. However, the fuel in the swirl pot may still partially contain bubbles, for example, due to strong dynamic driving movements of the vehicle and / or by a little filled vehicle tank and / or by an inclined position of the vehicle. The heater is dependent on a continuous and low-bubble fuel supply. In the worst case, the fuel sloshing away from the vehicle fuel tank or the bubbles present in the fuel, despite the use of the baffles, may result in high exhaust emissions combustion or extinction of a flame in a heater burner.

A known, generic heating device according to the first aspect is known for example from DE 100 60 355 Al. In this heating device, the heating device is coupled to the vehicle tank via a fuel feed pump. By coupling this heater to the fuel supply system of the vehicle, the application can be realized in a cost effective manner. However, operation of the fuel delivery pump is always necessary when a fuel filler is to be filled to a certain degree of filling with fuel. In order to remove fuel from the fuel tank, in turn, a conveyor is provided, which promotes the fuel from the fuel storage to the heater. For example, the case occurs that in the fuel storage tank too little fuel for the operation of the heater is present, it is imperative that the fuel delivery pump of the fuel supply system must be operated to promote fuel, even if an internal combustion engine of the vehicle is turned off. This leads to a high power take-off of a vehicle battery of the vehicle, which must provide the power required for the operation of the fuel feed pump.

Furthermore, a known, generic heating device according to the second aspect of DE 102 18 900 Al is known. In this heater is provided to ensure a fuel supply to the heater by the vehicle's own fuel pump is driven. For this purpose, the fuel pump of the vehicle is always operated when the heater is to be put into operation.

In both cases, the fuel delivery pump is therefore always operated when the operation of the heater is to be ensured. This may in some cases lead to faster discharge of the vehicle battery when the heater is operated in a parking heating operation with the internal combustion engine switched off. Under certain circumstances, this leads to the fact that the vehicle can not be started due to the strong discharge of the vehicle battery.

The invention is therefore based on the object, the generic heating devices and methods for controlling / regulating the fuel supply of such heating devices in such a way that the aforementioned disadvantages can be overcome at least partially. In particular, it is an object of the invention to at least reduce a risk of excessive discharge of the vehicle battery by stationary operations of the heating devices.

This object is solved by the features of the independent claims.

Advantageous embodiments and modifications of the invention will become apparent from the dependent claims.

According to the first aspect of the invention, the heating device according to the invention builds on the generic state of the art in that a control device is provided which is suitable to control the metering and conveying device with switched off or non-promoting fuel delivery pump so that they directly via the fuel feed pump fuel from the vehicle tank to the heater promotes and dosed a corresponding fuel supply. By coupling the heating device according to the invention to the already existing fuel supply system of the vehicle thus components can be used, which are already provided on the vehicle already. The promotion of the fuel to the heater is thus carried out by an interaction of the metering and conveying device of the heater and the fuel pump of the vehicle. In the case of a stationary heating operation, only the metering and conveying device conveys and meters fuel to the heating device. In this case, the fuel delivery pump of the vehicle is supercharged, that is to say the fuel is removed from the vehicle tank, in particular from a swirl pot in the vehicle tank, via the fuel feed pump and the fuel line to the heating unit. supported. In a Zuheizbetrieb the heater while the internal combustion engine of the vehicle, however, promotes the fuel pump of the vehicle at full power, the dosing and conveying device doses only the fuel to the heater. In addition to these two borderline cases, however, all intermediate stages are possible. A corresponding fuel volume flow or fuel mass flow to the heating device can be set, for example, via the metering and conveying device of the heating device.

The heating device according to the invention can be developed in an advantageous manner so that the control device is suitable for controlling the metering and conveying device in such a way that, in a stationary heating operation of the heating device with the fuel feed pump switched off or not conveying fuel to the heating device, directly from the vehicle tank via the fuel feed pump promotes and meters the fuel supply. The fuel pump with high power consumption in this case need not be controlled separately as in the prior art, to allow a fuel supply to the heater, but only the metering and conveying device with lower power consumption. The control or regulation of the fuel delivery pump of the vehicle, as well as the control of the metering and conveying device of the heater by the control unit or the control device of the heater or by an on-board control unit via an electric bus or its own electrical line done. The operation of the metering and conveying device instead of the fuel delivery device of the vehicle, the Fahrzeugbat- terie not so heavily loaded, since the power consumption of the metering and conveying device is less than the high power consumption of the fuel pump. The power consumption of an unregulated fuel pump is typically in the range of 60 to 100 watts. In order to reduce the discharge of the vehicle battery, the power to be output by the vehicle battery is reduced in accordance with the invention by operating the metering and conveying device of the heating device in the auxiliary heating mode. Furthermore, the heater according to the invention leads to the elimination of a separate tank removal and a separate conduit system for the heater, which costs are saved considerably. The vehicle's fuel and fuel lines are used. As a result, the long suction-side and pressure-side fuel lines of the heater are replaced by short lines.

Furthermore, the heating device according to the invention can be further developed such that the control device is suitable for controlling the metering and conveying device such that it merely meters the fuel supply to the heating device during a heating operation of the heating device while the fuel feed pump is running. Thus, the fuel delivery pump of the vehicle is operated during Zuheizbetriebs with the vehicle engine or engine running. The Leistungsentnähme the vehicle battery is thus not increased, since the fuel pump is taken in any case for fuel supply of the internal combustion engine in operation.

In addition, the heating device according to the invention can be realized so that the control device suitable is to operate both the fuel delivery pump and the metering and conveying device at least for fuel delivery at the same time, if the operating conditions of the vehicle and / or the heater require it.

Furthermore, the heating device according to the invention can be realized such that the control device is suitable for controlling the fuel feed pump at predetermined time intervals despite the present auxiliary heating operation in order to operate the fuel feed pump at least temporarily. As a result, a bubble-free fuel can be ensured with greater certainty. The fuel delivery pump is driven only in variable, predetermined time intervals for a defined period or a defined period of time to promote a certain amount of fuel. This ensures that the surge pot is sufficiently filled at all times and the fuel system of the vehicle is purged. The temporary intake of bubbles into the fuel system of the vehicle can be accepted to some extent if the system is sufficiently purged at defined intervals and thereby the bubbles are discharged from the fuel. The reliability of the heater is thereby increased because the occurrence of bubbles in the heater supplied fuel is greatly reduced.

Furthermore, the heating device according to the invention can be realized in such a way that the control device is suitable for controlling the fuel dispenser pump for conveying fuel, if the control of the metering and conveying device for conveying fuel to the heating device or the fuel delivery to the heating device are controlled by the door. sier and conveyor failed. Should the control or the fuel delivery through the metering and delivery device fail, the heating device can nevertheless be operated, since in this case the fuel pump of the vehicle conveys fuel.

Furthermore, the heating device according to the invention can be developed such that the heating device can be coupled to the fuel supply system of the vehicle via a fuel feed line of an internal combustion engine of the vehicle and / or a fuel return line of the internal combustion engine and / or a fuel-flow component on or in the internal combustion engine.

In connection with the first aspect of the invention, the method according to the invention builds on the generic state of the art in that the metering and conveying device with fuel pump switched off or not conveying fuel via the fuel delivery pump directly from the vehicle tank to the heater promotes and a corresponding fuel supply dosed. This results in the advantages explained in connection with the heating device according to the invention according to the first aspect of the invention in a similar or similar manner, and reference is therefore made to avoid repetition to the statements in connection with the heating device according to the invention according to the first aspect of the invention.

The same applies mutatis mutandis to the following preferred embodiments of the inventive method according to the first aspect of the invention, wherein in order to avoid weighing derholungen also in this regard, reference is made to the corresponding statements in connection with the heating device according to the invention according to the first aspect of the invention.

The inventive method can be developed in an advantageous manner such that the metering and conveying device in a stationary heating operation of the heater with switched off or not conveying fuel feed pump fuel to the heater directly from the

Vehicle tank via the fuel pump promotes and meters the fuel supply.

Furthermore, the method according to the invention can be realized in such a way that the metering and conveying device merely meters the fuel supply to the heating device in a heating operation of the heating device while the fuel feed pump is running.

In addition, the method according to the invention can be carried out so that both the fuel feed pump and the metering and conveying device are operated at the same time at least for fuel delivery, if the operating conditions of the vehicle and / or the heating device so require.

Furthermore, the method according to the invention can be designed so that the fuel feed pump is operated at least temporarily at predetermined time intervals despite the present auxiliary heating operation. In a preferred embodiment of the method according to the invention can be provided that the fuel pump is driven to fuel delivery when the control of the metering and conveying device for fuel delivery to the heater or the fuel delivery to the heater has failed by the metering and delivery.

Furthermore, the method according to the invention can be implemented such that the fuel for the heating device is taken from the fuel supply system of the vehicle via a fuel supply line of an internal combustion engine of the vehicle and / or a fuel return line of the internal combustion engine and / or a component through which fuel flows on or in the internal combustion engine becomes.

According to the second aspect of the invention, the heating device according to the invention builds on the generic state of the art in that a control device is provided which is suitable for driving the fuel delivery pump for fuel delivery in a heating operation of the heating device so that it is operated with a power consumption is lower than a power consumption of the operated in a Zuheizbetrieb the heater fuel feed pump. Thus, according to the invention, it is provided that the fuel delivery pump is operated in the usual manner with the power consumption required for the operation of the internal combustion engine during a heating operation when the internal combustion engine of the vehicle is running. In the auxiliary heating mode with the vehicle engine switched off, however, the fuel delivery pump is activated differently. This may be related by the controller. or the control device of the heater or by an on-board control device via an electronic bus or a separate electrical line done. Usually, the vehicle battery is heavily loaded or even widely discharged due to the high power consumption of the fuel pump. The power consumption of an uncontrolled fuel delivery pump is typically in the range of 60 to 100 watts. The discharge of the battery is therefore reduced in Vorliegendem Standheizbetrieb the heater so as not to jeopardize the next vehicle start. For this purpose, the heating device according to the invention provides to control the fuel feed pump during the parking heating operation so that their power consumption is reduced. This can be done, for example, by regulating or controlling to a low speed by means of pulse width modulation. In tests, it has been proven that a fuel delivery pump of the vehicle at a power consumption of 10 to 15 watts sufficient fuel to operate the heater or the heater. Otherwise, the advantages of the heating device according to the invention according to the first aspect of the invention arise mutatis mutandis.

The heating device according to the invention can be developed in an advantageous manner such that the valve device is preceded by a volumetric flow and / or mass flow sensor, via whose measured values a fuel volume flow can be controlled / regulated by the valve device. The fuel flow is thus determined via a mass flow or volume flow sensor. On the basis of the measured values of the sensor, the control device or the Control the fuel flow through the valve device accordingly control / regulate.

Furthermore, the heating device according to the invention can advantageously be further developed in such a way that an exhaust gas sensor is located downstream of the valve device and the heating device, via the measured values of which a fuel volume flow through the valve device can be controlled / regulated. Thus, with the exhaust gas sensor, the composition of the exhaust gas with respect to a substance relevant for the combustion in the heating device can be determined. For example, the concentration of carbon monoxide (CO), carbon dioxide (CO ₂ ) or oxygen (O ₂ ) can be measured. This can be concluded that a fuel-air ratio in a combustion chamber of the heater. For the relevant

Substance is set according to the operating conditions of the heater, a target value, wherein the control unit on the basis of the measured values of the exhaust gas sensor and the exhaust gas setpoint values controls the Brennstoffström via the valve means.

Furthermore, the heating device according to the invention can be formed so that the valve device is preceded by a pressure-reducing valve or a pressure sensor. By means of the pressure reducing valve, a pressure of the fuel supply system can be reduced to a pressure required for the operation of the heating device. Alternatively, a pressure sensor may be provided which measures a pressure in front of the valve device. On the basis of the detected pressure, for example, the volume / mass flow of the

Fuel are controlled by the valve device / regulated. In this context, the heating device according to the invention can be developed so that a heating unit upstream of the valve device and upstream or downstream of the pressure reducing valve or the pressure sensor. By providing the heating unit or the heating element of the fuel can be heated to a certain temperature, which is monitored for example by a temperature sensor. Knowing the fuel temperature and the type of fuel can be concluded that a certain viscosity of the fuel.

Furthermore, the heating device according to the invention can be realized such that the control device is suitable for controlling a fuel volume flow through the valve device based on a detected temperature and / or a detected pressure of the fuel by controlling the valve device. Thus, the controllable heating element or the heating unit heats the fuel before the valve device to a specific setpoint temperature. The actual temperature of the fuel can be measured and the heating power of the heating unit can thus be regulated accordingly. It is also possible to determine the temperature via the electrical resistance of the heating element. The heating power is controlled in this case exclusively on the electrical resistance of the heating element. When using the pressure reducing valve, a predetermined pressure is set in front of the valve device. Thus, knowing the fuel temperature using a temperature map, the fuel flow through the valve device can be controlled. If, however, instead of the pressure reducing valve, the pressure sensor used, the flow rate through the valve device can be controlled by means of a pressure-temperature map.

In connection with the second aspect of the invention, the method according to the invention builds on the generic state of the art in that the fuel feed pump for fuel delivery in a stationary heating operation of the heating device is controlled such that it is operated with a power consumption which is less than one

Power consumption of operated in a Zuheizbetrieb the heater fuel pump is. As a result, the advantages mentioned in connection with the heating device according to the invention according to the second aspect of the invention result in a similar or the same way, to avoid repetition reference is made to the statements in connection with the heating device according to the invention according to the second aspect of the invention.

The same applies mutatis mutandis to the following preferred embodiments of the method according to the invention according to the second aspect of the invention, reference being made in this regard to the corresponding embodiments in connection with the heating device according to the invention according to the second aspect of the invention.

The method according to the invention can be advantageously developed in such a way that the valve device is activated in the form of a clocking solenoid valve or a motor-operated control valve. Furthermore, the method according to the invention can be realized such that a fuel volume flow is controlled / regulated by the valve device on the basis of measured values of a volume flow and / or mass flow sensor arranged upstream of the valve device.

In addition, the method according to the invention can be implemented in such a way that a fuel volume flow through the valve device is controlled on the basis of measured values of an exhaust gas sensor downstream of the valve device and the heating device.

Furthermore, the inventive method can be implemented so that the valve device is controlled, which is preceded by a pressure reducing valve or a pressure sensor.

The method according to the invention is preferably configured in such a way that the valve device is actuated, upstream of which a heating unit upstream or downstream of the pressure-reducing valve or the pressure sensor is arranged.

In a further embodiment of the method according to the invention it can be provided that a fuel volume flow through the valve device based on a detected temperature and / or a detected pressure of the

Fuel is controlled by controlling the valve device / regulated.

Preferred embodiments of the invention are explained below by way of example with reference to the figures.

Show it: Figure 1 is a schematic representation of a heating device according to the prior art;

Figure 2 is a schematic representation of a heating device according to the invention according to a first embodiment of the invention, which is suitable for carrying out the method according to the invention;

Figure 3 is a schematic representation of a heating device according to a second embodiment of the invention, which is suitable for carrying out the method according to the invention;

Figure 4 is a schematic representation of a heating device according to the invention according to a third embodiment of the invention, which is suitable for carrying out the method according to the invention;

Figure 5 is a schematic representation of a heating device according to the invention according to a fourth embodiment of the invention, which is suitable for carrying out the method according to the invention; and

Figure 6 is a schematic representation of a heating device according to the invention according to a fifth embodiment of the invention, which is suitable for carrying out the method according to the invention.

FIG. 2 shows a schematic representation of a heating device 10 according to the invention according to a first embodiment. Example of the invention. The heating device 10 according to the invention comprises a heating device 30, which in this exemplary embodiment is a combustion heater that can be operated with fuel and engine-independently, in particular a parking heater, which has conventional components known to the person skilled in the art. The heater 30 is coupled to a fuel supply system of a vehicle via a fuel line 24. In the fuel line 24, a metering and conveying device 28, in particular a reciprocating metering pump, is provided. The metering and conveying device 28 is activated for operation by a control device 32 assigned to the heating device 10. The fuel supply system supplies a combustion engine 12 of a vehicle with fuel and for this purpose comprises a vehicle tank 18 with a surge pot 20 provided therein. For supplying fuel to the combustion engine 12, the combustion engine 12 is coupled to the vehicle tank 18 via a supply line 14. In particular, the feed line 14 opens into the swirl pot 20 within the vehicle tank 18. To convey the fuel, a fuel feed pump 22 is provided in the feed line 14, which is preferably arranged in the vicinity of the swirl pot 20. Furthermore, the internal combustion engine 12 is equipped with a return line 16, which just as the supply line 14 opens into the swirl pot 20 within the vehicle tank 18. The heater 30 is coupled to the vehicle tank 18 by at least one of three coupling lines 36, 38, 40 in this embodiment. A first coupling line 36 connects the fuel line 24 to the flow line 14. Preferably, the heater 30 is connected to the vehicle tank 18 only via the first coupling line 36. A second Coupling line 38 connects the fuel line 24 to the return line 16. Furthermore, a third coupling line 40 is provided, which couples the fuel line 24 with a component through which fuel flows in or on the internal combustion engine 12. For controlling the metering and conveying device 28, the control device 32 is provided, which is coupled in particular via a control line 34 with the metering and conveying device 28. The control device 32 may be an already existing control device of the vehicle or a separate control device 32 provided for the heating device 10. Therefore, the control device 32 is either coupled via a bus system to a vehicle-specific control device, not shown, or coupled directly to the fuel delivery pump 22 of the vehicle's own fuel supply system.

The operation of the heating device according to the invention or the method according to the invention for controlling / regulating a fuel supply of the engine-independently operable heating device 30 is as follows. In a Zuheizbetrieb the internal combustion engine 12 of the vehicle is running. Therefore, the fuel delivery pump 22. operated, which provides the internal combustion engine 12 via the vehicle tank 18, in particular via the swirl pot 20 within the vehicle tank 18, fuel via the flow line 14. A portion of this fuel can pass through the return line 16 back into the swirl pot 20 within the vehicle tank 18. Through the pressure built up by the fuel feed pump 22, fuel passes via at least one of the three coupling lines 36, 38, 40 into the fuel line 24 of the heating device 10. The fuel flows from the fuel line 24 via the metering and conveying device 28 to the heater 30. In this case, the control device 32 controls the metering and conveying device 28 such that it only meters and sets a required for the operation of the heater 30 fuel flow or fuel mass flow. A promotion by the metering and delivery device is not required in this case due to the current fuel delivery pump 22 of the vehicle.

In a parking heating mode, the internal combustion engine 12 is switched off. Therefore, the fuel delivery pump 22 of the vehicle is not operated because the fuel supply of the engine 12 is not required. However, in order to supply the heating device 30 with fuel for the auxiliary heating operation, the control device 32 controls the metering and conveying device 28, so that it is operated in a conveying operation for fuel supply of the heating device 30. Thus, the metering and delivery device 28 sucks via the fuel line 24 and at least one of

Coupling lines 36, 38, 40 fuel from the vehicle tank 18, in particular from the swirl pot 20. Preferably, fuel is sucked only via the first coupling line 36 from the flow line 14 via the fuel pump 22 from the swirl pot 20 within the vehicle tank 18. As a result, the fuel feed pump 22 is sucked by the metering and conveying device 28. Accordingly, the auxiliary heating operation of the heating device 30 can be ensured by the metering and conveying device 28, wherein the metering and conveying device 28 in this case promotes and doses. In an alternative embodiment of the heating device according to the invention, the metering and conveying device 28 of Figure 2 is replaced by a valve device which is formed by a clocking solenoid valve or a motorized control valve and thus only for dosing the fuel flow to the heater 30 is capable.

In this case, the method according to the invention is designed as follows. In a Zuheizbetrieb the heater

30, the engine 12 is operated. Accordingly, the fuel delivery pump 22 is also operated to provide fuel to the engine 12 via the supply line 14. As a result, the heating device 30 is supplied with fuel via at least one of the coupling lines 36, 38, 40 and the fuel line 24. The control device 32 controls the valve device such that a corresponding volume flow or mass flow of fuel flows to the heating device 30. Accordingly, the operation of the heater 30 is ensured.

In a parking heating operation of the heater 30, the engine 12 is turned off. Since the metering and conveying device 28 is replaced by the valve device, it is necessary to control the fuel feed pump 22 via the control device 32. However, the fuel delivery pump 22 for the operation of the heater 30 does not need to be driven with a power consumption that would be required for the operation of the internal combustion engine 12. Therefore, the control device 32 controls the fuel feed pump 22 for fuel delivery to the heating Device 30 such that the fuel delivery pump 22 is operated with a power consumption that is less than a power consumption with which the fuel delivery pump 22 would have to be operated during operation of the internal combustion engine 12. Preferably, the fuel delivery pump 22 is driven with a power consumption of 10 to 15 watts, so that the heater 30 can be supplied with sufficient fuel from the vehicle tank 18.

FIG. 3 shows a schematic representation of a heating device 100 according to the invention in accordance with a second exemplary embodiment of the invention. In order to avoid repetition, in describing this exemplary embodiment, only the differences from the alternative exemplary embodiment in FIG. 2 will be discussed, wherein identical or similar components are designated by similar reference numerals. In this exemplary embodiment, the heating device 130 is preceded by a volumetric flow or mass flow sensor 142 in the fuel line 124, wherein the valve device 128 is arranged between the volumetric flow or mass flow sensor 142 and the heating device 130. Thus, the volume flow or mass flow of the fuel in the fuel line 124 can be detected both in the auxiliary heating mode and in the auxiliary heating mode. On this basis, the control device 132 controls the volume flow or mass flow of the fuel in the fuel line 124, in that the control device 132 controls the valve device 128 for volume flow metering accordingly.

FIG. 4 shows a schematic representation of a heating device 200 according to the invention in accordance with a third exemplary embodiment of the invention. To avoid recurrence In the description of this exemplary embodiment, only the differences from the alternative exemplary embodiment of FIG. 2 are discussed, wherein identical or similar components are designated by similar reference numerals. In this embodiment, only one valve means 228 in the fuel line 224 of the heater 230 is upstream, and further downstream of an exhaust gas sensor 244 of the heater. In this case, the exhaust gas sensor 244 is coupled to the control device 232, as a result of which the control device 232 receives the measured values of the

Exhaust gas sensor 244 can be provided. In accordance with the measured values of the exhaust gas sensor 244, the control device 232 controls the volume flow or mass flow of the fuel through the fuel line 224 by actuating the valve device 228. Preferably, the exhaust gas sensor 244 detects a concentration of carbon monoxide (CO), carbon dioxide (CO ₂ ), or oxygen (O ₂ ). Based on the composition of the exhaust gas from the heater 230, a fuel-air ratio in a combustion chamber of the heater 230 may be deduced, with the valve device 228 being driven accordingly based on a detected combustion relevant material. Thus, the control of the volumetric flow or mass flow in the fuel line 224 to the heater 230 is based on the detected readings of the exhaust gas sensor 244.

FIG. 5 shows a schematic representation of a heating device 300 according to the invention in accordance with a fourth exemplary embodiment of the invention. To avoid repetition, the description of this embodiment Play only on the differences to the alternative embodiment of Figure 2, with the same or similar components are designated by like reference numerals. In this case, in the fuel passage 324 in the flow direction of the fuel supplied from the vehicle tank 318, a pressure reducing valve 346, a heating unit 348, a temperature sensor 350, and the valve device 328 precede the heater 330. In this case, the pressure reducing valve 346 sets a certain pressure in front of the valve device 328. The controllable heating unit 348 heats the delivered fuel to a certain desired temperature. The actually present temperature of the fuel is detected by the temperature sensor 350, the measured values being made available to the control device 332 and the control device 332 correspondingly regulating the heating power of the heating unit 348 in order to possibly vary the actual temperature and the setpoint temperature to keep low. Alternatively, it is also possible to determine the temperature via an electrical resistance of the heating unit 348 and thus not to provide a temperature sensor 350. By means of a temperature characteristic map and in knowledge of the pressure of the fuel prespecified by the pressure reducing valve 346, the fuel flow, ie the volume flow or mass flow of the fuel, can thus be controlled by triggering the fuel flow

Valve device 328 control / regulate, for example by appropriate timing of a valve device 328 forming Magnetventi1s.

FIG. 6 shows a schematic representation of the heating device 400 according to the invention in accordance with a fifth exemplary embodiment of the invention. To avoid repetition In the description of this exemplary embodiment, only the differences from the preceding fourth exemplary embodiment are described, wherein identical or similar components are designated by similar reference numerals. In this embodiment, the pressure reducing valve 346 is replaced by a pressure sensor 452. In this case, the pressure sensor 452 measures a pressure of the fuel present in the fuel line 424 in front of the valve device 428. The controllable heating unit 448 heats the fuel to a specific desired temperature, this temperature being detected by the temperature sensor 450. The fuel flow, that is to say the volumetric flow or mass flow of the fuel, is regulated by actuation of the valve device 428 via a pressure-temperature characteristic diagram or a pure pressure characteristic diagram at a fixed predetermined temperature by the heating unit 448.

The features of the invention disclosed in the foregoing description, in the drawings and in the claims may be essential to the realization of the invention both individually and in any combination.

List of reference numbers:

10 'heater 12' internal combustion engine

14 'supply line

16 'return line

18 'vehicle tank

20 'swirl pot 22' fuel pump

24 'fuel line

26 'further fuel line

28 'reciprocating dosing pump

30 'heating device 32' control device

34 'control line

10 heating device

12 internal combustion engine

14 supply line 16 return line

18 vehicle tank

20 baffle pot

22 fuel pump

24 fuel line 28 metering and conveying device

30 heating device 32 control device 34 control line

36 first coupling line 38 second coupling line

40 third coupling line 100 heating device 112 internal combustion engine

114 flow line

116 return line

118 Vehicle tank 120 Swirl pot

122 fuel pump

124 fuel line

128 valve device

130 heating device 132 control device

136 first coupling line

138 second coupling line

140 third coupling line

142 Flow or mass flow sensor 200 Heating device

212 internal combustion engine

214 flow line

216 return line

218 Vehicle tank 220 Swirl pot

222 fuel pump

224 fuel line

228 valve device

230 heating device 232 control device

236 first coupling line

238 second coupling line

240 third coupling line

244 Exhaust gas sensor 300 Heating device

312 internal combustion engine

314 supply line 316 return line

318 vehicle tank

320 baffle pot

322 fuel pump 324 fuel line

328 valve device

330 heating device

332 control device

336 first coupling line 338 second coupling line

340 third coupling line

346 Pressure reducing valve

348 heating unit

350 temperature sensor 400 heating device

412 combustion engine

414 flow line

416 return line

418 Vehicle tank 420 Swirl pot

422 fuel pump

424 fuel line

428 valve device

430 heating device 432 control device

436 first coupling line

438 second coupling line

440 third coupling line

448 Heating unit 450 Temperature sensor

452 pressure sensor

Claims

A heater (10) for a vehicle having a motor-driven, fuel-operable heater

(30) which can be coupled to a fuel supply system of the vehicle such that the heating device (30) is connected to a vehicle tank (18) at least via a fuel delivery pump (22) of the fuel supply system, and to a metering and conveying device (28). for supplying and metering fuel to the heating device (30), wherein the metering and conveying device (28) downstream of the fuel feed pump (22) and upstream of the heating device (30), characterized in that a control device (32) is provided which is suitable is to control the metering and conveying device (28) with switched off or not conveying fuel pump (22) such that it promotes fuel via the fuel pump (22) directly from the vehicle tank (18) to the heating device (30) and a corresponding fuel - dispensing dosed.

2. Heating device according to claim 1, characterized in that the control device (32) is suitable for controlling the metering and conveying device (28) in such a way that it can be operated in a stand heating mode of the heating device (30) when the fuel feed pump (22) is switched off or not ) Fuel to the heater (30) directly from the Vehicle tank via the fuel pump (22) promotes and meters the fuel supply.

3. Heating device according to one of claims 1 or 2, characterized in that the control device (32) is adapted to control the metering and conveying device (28) such that they in a Zuheizbetrieb the heater (30) while the fuel feed pump ( 22) merely metered the fuel supply to the heating device (30).

4. Heating device according to one of claims 1 to 3, characterized in that the control device (32) is adapted to operate both the fuel delivery pump (22) and the metering and conveying device (28) at least for fuel delivery at the same time, if the operating conditions of Vehicle and / or the heater (30) require it.

5. Heating device according to one of claims 1 to 4, characterized in that the control device (32) is adapted to control the fuel delivery pump (22) despite prevailing stationary heating at predetermined time intervals in order to operate the fuel delivery pump (22) at least temporarily.

6. Heating device according to one of claims 1 to 5, characterized in that the control device is adapted to control the fuel delivery pump (22) for fuel delivery, when the control of the metering and conveying device (28) for conveying fuel to the heater (30) or the fuel delivery to the heating tion (30) by the metering and conveying device (28) failed.

7. Heating device according to one of claims 1 to 6, characterized in that the heating device (30) with the fuel supply system of the vehicle via a fuel feed line (14) of an internal combustion engine (12) of the vehicle and / or a fuel return line (16) of the internal combustion engine (12) and / or a component through which fuel flows can be coupled to or in the internal combustion engine (12).

8. A method for controlling a fuel supply of a motor-independently operable heater (30) for a vehicle, wherein the heater (30) is coupled to a fuel supply system of the vehicle such that the heater (30) at least via a fuel delivery pump (22) of the fuel supply system is connected to a vehicle tank (18), wherein a metering and conveying device (28) for supplying and metering of fuel to the heater (30) of the fuel delivery pump (22) downstream and the heater (30) upstream, characterized in that the dosing - And conveyor (28) with switched off or not promoting fuel pump (22) fuel via the fuel pump (22) directly from the vehicle tank (18) to the heater (30) promotes and meters a corresponding fuel supply.

9. The method according to claim 8, characterized in that the metering and conveying device (28) in a stationary heating operation of the heating device (30) when switched off o- the non-promoting fuel delivery pump (22) promotes fuel to the heater (30) directly from the vehicle tank via the fuel delivery pump (22) and dosed the fuel supply.

10. The method according to any one of claim 8 or 9, characterized in that the metering and conveying device (28) in a Zuheizbetrieb the heater (30) while the fuel feed pump (22), the fuel supply to the heater (30) only dosed.

11. The method according to any one of claims 8 to 10, characterized in that both the fuel delivery pump (22) and the metering and conveying device (28) are operated at least for fuel delivery at the same time when the operating conditions of the vehicle and / or the heating device (30 ) require this.

12. The method according to any one of claims 8 to 11, characterized in that the fuel feed pump (22) is operated at least temporarily at predetermined time intervals, despite the present auxiliary heating operation.

13. The method according to any one of claims 8 to 12, characterized in that the fuel delivery pump (22) for

Fuel supply is controlled when the control of the metering and conveying device (28) for fuel delivery to the heater (30) or the fuel delivery to the heater (30) by the metering and conveying device (28) failed.

14. The method according to any one of claims 8 to 13, characterized in that the fuel for the heater (30) from the fuel supply system of the vehicle via a fuel supply line (14) of an internal combustion engine (12) of the vehicle and / or a fuel return line (16) of the Internal combustion engine (12) and / or a fuel-flow component on or in the internal combustion engine (12) is removed.

15. A heater (10; 100; 200; 300; 400) for a vehicle having an engine independent fuel operable heater (30; 130; 230; 330; 430), the heater being coupled to a fuel supply system of the vehicle such, in that the heating device is at least connected via a fuel feed pump (22; 122; 222;

322; 422) of the fuel supply system is connected to a vehicle tank (18; 118; 218; 318; 418), downstream of which a valve device (128; 228; 328; 428) for metering a fuel supply to the heating device of the fuel delivery pump and upstream of the heating device, characterized in that a control device (32; 132; 232; 332; 432) is provided, which is suitable for controlling the fuel feed pump for fuel delivery in a heating operation of the heating device so that it is operated with a power consumption which is less than a power consumption of the in a Zuheizbe- drive the heater operated fuel pump is.

16. Heating device according to claim 15, characterized in that the valve device (128; 228; 328; 428) a clocking solenoid valve or a motorized control valve is.

17, heating device (100) according to claim 15 or 16, characterized in that the valve device (128) is preceded by a volume flow and / or mass flow sensor (142), on the measured values of a fuel flow through the valve means (128) controllable / controllable is.

18. Heating device (200) according to claim 15 or 16, characterized in that the valve device (228) and the heating device (230) an exhaust gas sensor (244) is downstream, via the measured values of a fuel flow through the valve means (228) is controllable / controllable ,

19. A heating device (300; 400) according to claim 15 or 16, characterized in that the valve device (328; 428) is preceded by a pressure reducing valve (346) or a pressure sensor (452).

20. A heating device (300; 400) according to claim 19, characterized in that a heating unit (348) upstream of the valve device (328; 428) and upstream or downstream of the pressure reducing valve (346) or the pressure sensor (452).

21. A heating device (300; 400) according to claim 19 or 20, characterized in that the control device (332; 432) is adapted to a fuel volume flow through the valve means (328; 428) based on a detected temperature and / or pressure of the fuel by controlling the valve means (328, 428) to control.

22. A method for controlling / regulating a fuel supply of a motor-independently operable heater

(30; 130; 230; 330; 430) for a vehicle, wherein the heater is coupleable to a fuel supply system of the vehicle such that the heater is at least via a fuel delivery pump (22; 122; 222; 322; 422) of the fuel supply system with a vehicle tank (18; 118; 218; 318; 418), wherein a valve device (128; 228; 328; 428) for metering a fuel supply to the heating device downstream of the fuel feed pump and upstream of the heating device, characterized in that the fuel feed pump for fuel delivery in a stationary heating operation of the heating device is driven in such a way that it is operated with a power consumption which is lower than a power consumption of the operated in a Zuheizbetrieb the heating device fuel pump.

A method according to claim 22, characterized in that the valve means (128; 228; 328; 428) is driven in the form of a clocking solenoid valve or a motor operated control valve.

24. The method according to claim 22 or 23, characterized in that a fuel volume flow through the valve device (128) on the basis of measured values of the valve device (128) upstream volume flow and / or mass flow sensor (142) is controlled / regulated.

25. A method according to claim 22 or 23, characterized in that a fuel volume flow through the valve means (228) is controlled based on measurements of one of the valve means (228) and the exhaust gas sensor (244) downstream of the heater (230). is regulated.

26. The method according to claim 22 or 23, characterized in that the valve device (328; 428) is driven, which is preceded by a pressure reducing valve (346) or a pressure sensor (452).

27. The method according to claim 26, characterized in that the valve device (328, 428) is controlled, which is upstream of a pressure reducing valve (346) or the pressure sensor (452) upstream or downstream heating unit (348; 448).

28. The method according to claim 26 or 27, characterized in that a fuel volume flow through the valve means (328; 428) is controlled based on a detected temperature and / or a detected pressure of the fuel by driving the heating unit (348).