VEHICLE COMPONENT, IN PARTICULAR FUEL PUMP, HOUSING AS A HEAT SEAT FOR SUCH A PUMP AND METHOD FOR DISCONTINUED HEAT DISTRIBUTION

Abstract

Fuel pump (2), which is attached to an internal combustion engine (6) of a vehicle by a mounting side (8) and with a pump chamber (16) through which a fuel flows during operation of the vehicle, wherein a heat sink (26) is arranged, with a heat storage medium (32), wherein the heat sink (26) is designed such that in a shutdown mode of the vehicle during a post-heating period (N) the heating of the fuel due to post-heating heat is limited to a maximum temperature (M), wherein the heat sink (26) is arranged on a side of the fuel pump (2) that is facing away from the mounting side (8).

Description

[0001] The invention relates to a vehicle component, in particular a fuel pump for a vehicle, with a pump chamber through which fuel flows during vehicle operation. The invention further relates to a heat sink designed as a housing. The invention also relates to a method for dissipating residual heat, particularly from a vehicle's fuel pump.

[0002] Fuel pumps for vehicles are well-known and typically serve to deliver fuel from the vehicle's fuel tank to an internal combustion engine. For this purpose, the fuel tank and the engine are connected by a suitable fuel line system, along which the fuel pump is located. This is often a high-pressure pump that divides the fuel line system into a low-pressure system on the tank side and a high-pressure system on the engine side. The low-pressure system maintains a pre-supply pressure, which is typically up to about 6 bar. An additional tank pump, often an electric fuel pump, is also usually installed on the tank side.Typically, the fuel pump therefore includes a pump chamber that is divided into a low-pressure side and a high-pressure side, with the fuel pump being, for example, a piston pump that transfers fuel from the low-pressure side to the high-pressure side by means of a periodically moving piston.

[0003] The internal combustion engine typically generates waste heat, which warms the fuel pump and the fuel it contains, often mounted close to the engine. This can cause the fuel to heat up above its vaporization temperature and evaporate, starting with its more volatile components. The vaporization temperature is primarily determined by the fuel delivery pressure and the type of fuel, and is typically around 100 °C. Modern fuels tend to have lower vaporization temperatures, especially due to the addition or use of ethanol. When the fuel evaporates, the fuel pump no longer operates correctly, and it becomes impossible to achieve the required pressure build-up in the high-pressure fuel line.Such a malfunction of the fuel pump subsequently leads to a corresponding drop in pressure on the high-pressure side and usually to the engine stalling and possibly a breakdown.

[0004] During operation and with the combustion engine running, sufficient cooling is typically achieved through the continuous flow of low-temperature fuel, for example, between 40 and 80 °C. Often, additional cooling of at least the combustion engine is also provided by airflow. However, the waste heat generated by the combustion engine when the vehicle is switched off (i.e., when the engine is off) poses a problem. In this case, there is no additional cooling via airflow or fuel circulation, and the risk of evaporation is particularly high.Although thermal equilibrium with the surroundings does occur after a certain period, such that the fuel temperature eventually falls below its vaporization temperature, there is a risk that the combustion engine cannot be restarted due to potential fuel vaporization in the fuel pump. The reheating period, during which the combustion engine is not yet in thermal equilibrium with the surroundings, typically depends on the type of engine. For example, the time it takes to cool below 100 °C is approximately one hour. The problem described above then arises particularly with correspondingly shorter shutdown times.

[0005] Reference is made to US 2011 / 0203947A1, DE 19957742A1, FR 2996880A1 and JP 2013-185452A.

[0006] JP 2013- 185 452 A describes an injection valve with latent heat storage.

[0007] DE 199 57 742 A1 describes a high-pressure fuel pump which is cooled with water as a coolant.

[0008] Therefore, it is an object of the invention to provide a vehicle component, in particular a fuel pump for a vehicle, and a method for dissipating residual heat in order to prevent malfunction of the vehicle component due to overheating, especially to prevent malfunction due to vaporized fuel in the event of restarting the vehicle's internal combustion engine. In particular, the fuel pump should also be as simple and cost-effective to manufacture as possible. Furthermore, it is an object to provide a housing that serves as a suitable heat sink for attachment to the vehicle component, preferably the fuel pump.

[0009] The problem is solved according to the invention by a vehicle component, in this case a fuel pump, with the features of claim 1, and by a housing with the features of claim 6. Furthermore, the invention is solved by a method with the features of claim 7. Advantageous embodiments, further developments, and variants are the subject of the dependent claims. The advantages and embodiments mentioned in connection with the fuel pump also apply mutatis mutandis to the housing and the method.

[0010] The fuel pump is designed for use in a vehicle and has a pump chamber through which fuel flows during vehicle operation. Specifically, the fuel pump is a high-pressure pump and not a tank pump. Furthermore, a heat sink is provided, containing a heat storage medium. The heat sink is designed such that, during a vehicle shutdown period, the heating of the fuel due to residual heat is limited to a maximum temperature.

[0011] A particular advantage of the invention is that the heat sink limits the temperature rise in the vehicle component, especially in the fuel pump, thus acting as a kind of thermal safety device. The residual heat generated during the vehicle's shutdown mode, particularly by an internal combustion engine, but potentially also by an exhaust system or other components, is absorbed by the heat sink, thereby preventing excessive fuel evaporation. This can occur either directly with the heat storage medium of the heat sink absorbing the residual heat, or alternatively or additionally, with the fuel initially partially evaporating but then immediately condensing again by absorbing heat into the heat sink. In either case, excessive fuel evaporation is advantageously prevented.This ensures that the combustion engine can be restarted at any time, particularly after the vehicle has been switched off. This prevents fuel pump malfunctions. This is especially important given the increasing gap between engine temperature and vaporization temperature: firstly, newer combustion engines are increasingly operated at higher temperatures and consequently generate more waste heat and higher fuel pump temperatures when switched off; secondly, new fuels often have lower vaporization temperatures. Both trends combined lead to an increased risk of vaporization.

[0012] The presented concept of thermal protection against residual heat can also be applied to other vehicle components, such as temperature-sensitive electronics. In such cases, it may only be necessary to adapt the chosen heat storage medium to the prevailing temperature conditions and, if necessary, to modify the heat sink's design. The advantages then become particularly apparent, as described above and below in connection with the fuel pump. In a preferred embodiment, the heat sink thus serves as thermal protection for a vehicle component. The same applies to the described method for dissipating residual heat. The principle of thermal protection is explained below, without loss of generality, using the fuel pump as an example.

[0013] A further advantage of the invention is that, in order to limit the heating of the fuel due to post-heating, no active cooling is required; rather, passive cooling is achieved by the heat sink and the heat storage medium. In other words, no additional energy is required for cooling, which has a particularly positive impact on the vehicle's CO2 balance.

[0014] When the vehicle is switched off, the combustion engine and the fuel pump are shut down. This occurs, for example, when the vehicle is parked, but it is also conceivable that the vehicle is driven in stop-and-go traffic, where the combustion engine is repeatedly switched on and off. Additionally, a hybrid vehicle, in particular, can be operated in a standby mode in which the combustion engine is switched off, but the vehicle continues to move using an electric drive. In all these examples, the fuel flow in the fuel line system to the combustion engine also comes to a standstill, and the fuel can be heated by absorbing waste heat from the combustion engine, which was just running.Immediately after being switched off, the combustion engine, for example, has a surface temperature of about 120 °C, whereas the fuel pump and the fuel contained within it have a temperature of about 20 to 90 °C at the beginning of the shutdown mode.

[0015] In shutdown mode, the combustion engine undergoes thermalization, releasing heat to the surroundings and, in particular, to the fuel pump and the fuel it contains. As time progresses, the engine temperature and the amount of heat it releases decrease. This initially results in a temperature increase for the fuel pump and the fuel, reaching a certain peak temperature. Following this, as the heat generated by the pump diminishes, they cool down towards the ambient temperature. During this initial temperature rise, the fuel temperature may exceed its vaporization temperature, only to fall below it again after a certain period of cooling.The heat sink limits the heating of the fuel by absorbing any heat energy that would cause it to rise above a maximum temperature. Advantageously, the maximum temperature is lower than the peak temperature, thus preventing it from reaching the latter. The heat absorbed by the heat storage medium is then no longer available for fuel vaporization, thereby reducing or even completely preventing it. In other words, the heat storage medium of the heat sink absorbs residual heat that would otherwise lead to fuel vaporization. Alternatively or additionally, the heat sink extracts heat from the heated fuel, thereby enabling the condensation of already vaporized fuel. Here, too, excessive fuel vaporization is advantageously prevented by returning the fuel to its liquid state.

[0016] In a particularly suitable embodiment, the heat storage medium is a latent heat storage device, that is, in particular, a heat storage device in which heat is stored not merely in the form of a temperature increase but additionally or even exclusively through a phase transition. Such latent heat storage devices are known per se and usually serve to store heat for later heat release or heating. Here, however, the heat storage device primarily serves to absorb heat and thus represents a kind of thermal safety device. This safety function is realized in particular by the fact that heat is absorbed at the phase transition, but no temperature increase occurs, especially at least when heat transfer effects are neglected. Thus, the temperature is advantageously limited to the respective phase transition temperature of the heat storage device.

[0017] Both solid-to-liquid and liquid-to-gas phase transitions are suitable for heating. Up to the phase transition temperature, the heat storage medium, and especially the fuel, heats up. However, upon reaching the phase transition temperature, the temperature does not rise further; instead, the heat storage medium melts or vaporizes. The fuel temperature is therefore limited by the maximum temperature, which in turn is determined by the phase transition temperature.

[0018] The heat storage medium is preferably selected with regard to its phase transition temperature, its heat capacity, and, in particular, with regard to safety-relevant properties such as toxicity or flammability. Suitable options from this perspective include xylitol and fructose, which are also particularly cost-effective. Water is another suitable alternative, exhibiting a favorable phase transition temperature, especially compared to conventional fuels. Sugars, alcohols, paraffins, or hydrated salts are also generally suitable, particularly with regard to their phase transition temperature.

[0019] To ensure good heat dissipation to the environment, both generally and especially in the relatively uncritical case of only moderate heating (i.e., without exceeding the evaporation temperature), the heat storage medium expediently possesses the highest possible thermal conductivity. To further improve thermal conductivity, an additive, such as graphite or another material with suitable thermal conductivity, is mixed into the heat storage medium in a preferred embodiment. In an advantageous further development, or alternatively, the addition of an additive also achieves a targeted impurity, which advantageously allows for control of the phase transition during cooling, i.e., during crystallization or condensation.

[0020] To prevent fuel evaporation as effectively as possible, in a suitable design the maximum temperature is a phase transition temperature, corresponding at most to the fuel's evaporation temperature and falling no more than 15 °C below it. This means, in particular, that ideally the maximum temperature corresponds to the phase transition temperature, and that an actual maximum temperature may differ slightly from this due to technical and / or design reasons. In particular, a temperature gradient often occurs across the entire fuel pump. If, for example, the fuel is positioned closer to the combustion engine than the heat storage medium, the fuel is exposed to a correspondingly higher temperature.In this example, the actual maximum temperature is then slightly higher, for example about 5 to 10 °C, than the ideal maximum temperature and the phase transition temperature.

[0021] The maximum temperature to which fuel heating is limited corresponds to the evaporation temperature or is slightly below it. The lower limit is determined in particular by the operating temperature present in the fuel pump during operation and is preferably higher to prevent premature phase transition and stress on the heat storage medium, ensuring that it is available with full heat capacity after shutdown. This prevents the phase transition of the heat storage medium before the fuel evaporates, thus preventing evaporation particularly effectively and reliably.

[0022] The heat storage medium is therefore expediently selected depending on the approved fuels and their respective minimum evaporation temperatures. Particular attention must also be paid to the pressure conditions in the fuel line system, which correspondingly influence the evaporation temperature. Fuels used today in conventional systems mostly have an evaporation temperature of around 100 °C, so materials with a melting point in the range of approximately 85 to 100 °C are particularly suitable as heat storage media.

[0023] The heat storage medium is expediently dimensioned with respect to its heat absorption capacity such that the heat to be absorbed during the reheating phase corresponds at most to this heat absorption capacity. The amount of heat storage medium used is therefore preferably designed with a worst-case scenario in mind, involving maximum generation of reheating heat. In a conventional vehicle, for example, under maximum load in standby mode, a waste heat of approximately 7.9 to 10.6 kJ needs to be absorbed, which, with a safety margin, can be absorbed by approximately 30 to 40 g of xylitol as a heat storage medium.

[0024] To compensate for any temperature difference between the evaporation and melting temperatures, additional insulation is appropriately provided. For example, the heat storage medium surrounds the pump chamber and is itself enclosed by insulation. Due to the heat storage medium's external location relative to the pump chamber, a temperature gradient initially arises without insulation, such that the heat storage medium, due to thermalization with the surroundings, is cooler than the fuel in the pump chamber; a corresponding temperature difference is the result. The additional insulation then makes it possible to reduce this temperature difference and, by appropriately selecting the insulation material and wall thickness, to control heat loss and thus the temperature difference by reducing heat transfer to the surroundings.The temperature present at the heat storage medium can therefore be adjusted to its melting point, and the maximum temperature can be optimally adjusted with respect to the evaporation temperature.

[0025] The fuel pump is often mounted directly to the vehicle's combustion engine. In this case, the heat sink is located on the side of the fuel pump facing away from the mounting side. In other words, the heat sink is located on the side of the fuel pump facing away from the combustion engine. This prevents excessive heat buildup on the heat sink from the engine's residual heat and ensures that only the heat that would otherwise cause the fuel to evaporate is absorbed, or actually does evaporate, and is subsequently removed by the heat sink. The fuel pump is specifically mounted to the combustion engine in such a way that liquid fuel collects on the mounting side. As it evaporates, this liquid fuel rises towards the heat sink, where it is cooled below its evaporation temperature by transferring heat to the heat storage medium.The heat capacity present in the heat storage medium is thus used particularly efficiently. However, an equally suitable alternative is to position the heat sink at the mounting point, thereby completely preventing fuel evaporation.

[0026] To ensure a particularly stable construction, the heat sink is designed as a suitable housing for mounting on the fuel pump. The housing has a cavity to hold the heat storage medium. For example, the housing is designed like a cap or cover and is simply placed onto a conventional fuel pump for installation and preferably additionally secured, for example, by screws or a plug-in mechanism. The heat sink is therefore particularly suitable as an adapter for upgrading existing fuel pumps. This eliminates the need to develop a completely new fuel pump. Furthermore, its design as a separate component allows for easy replacement of the heat sink.

[0027] Generally, various housing designs with regard to the cavity are conceivable: In one suitable variant, the cavity is completely enclosed by the housing; in another variant, the cavity is limited by the rest of the fuel pump. In an advantageous alternative, the housing is designed as a casing or as a ring with an annular cavity that runs around the pump chamber.

[0028] In another suitable and particularly compact design, the heat sink is integrated into the fuel pump in such a way that no separate housing is required; instead, the cavity or cavities are incorporated directly into the walls of the fuel pump. In a suitable variant, the heat sink is located directly within the pump chamber, for example, as a housing filled with the heat storage medium.

[0029] The housing is preferably made of a material with the best possible thermal conductivity to ensure optimal heat transfer to the heat storage medium. For example, the housing is made of steel or sheet metal, and is particularly cost-effective to manufacture using a deep-drawing process, or alternatively from aluminum and as a die-cast part. Alternatively, the housing can be made of plastic, which is also particularly cost-effective.

[0030] In the method for dissipating residual heat from the fuel pump, the heating of the fuel in the fuel pump during a post-heating period is limited to a maximum temperature by absorbing residual heat during the vehicle's shutdown mode. This post-heating period extends from the start of the shutdown mode, i.e., when the combustion engine is switched off, until the point at which extensive thermalization with the environment has occurred. "Extensive" here means that the heat dissipation to the environment significantly exceeds the absorption of residual heat, for example, by a factor of four. During the post-heating phase, the fuel initially heats up, potentially exceeding the vaporization temperature, reaches a peak temperature, and finally falls below the vaporization temperature again.In the case of the fuel pump with an attached heat sink, heating only occurs up to the maximum temperature, which preferably corresponds to no more than the evaporation temperature. Once the maximum temperature is reached, heat is absorbed by the heat storage medium through a phase transition.

[0031] Towards the end of the post-heating phase, the heat storage medium cools down below its maximum temperature, specifically below its phase transition temperature. The period up to this point is also referred to as the hot phase. In a suitable further development, the heat storage medium is then at least partially regenerated by heat release during a subsequent cooling phase following this hot phase. In this way, the heat storage medium is again available as a thermal buffer when the combustion engine is switched on and then off again. The cooling phase thus represents, in particular, a regeneration phase in which the heat initially stored in the hot phase is released. This also involves a corresponding phase transition in the opposite direction, for example, from liquid to solid.However, crystallization does not necessarily occur at the phase transition temperature, but may only occur at a lower temperature due to subcooling of the heat storage medium. In a particularly advantageous configuration, by selectively triggering crystallization, it is also possible to release the heat generated during the phase transition at a specific time and use it for heating purposes.

[0032] An embodiment of the invention is explained in more detail below with reference to a drawing. The drawing shows: Fig. 1 a fuel pump with a heat sink, Fig. 2 schematically a fuel line system, and Fig. 3. Temperature profiles at the fuel pump as a function of time.

[0033] In Fig. Figure 1 shows a cross-section of a fuel pump 2, for use in a fuel line system 4, such as that found, for example, in Fig. Figure 2 is shown schematically. In the embodiment shown here, the fuel pump 2 is mounted on an internal combustion engine 6 of a vehicle (not shown in detail). The fuel pump 2 includes a mounting side 8 facing the internal combustion engine 6. In this embodiment, the fuel pump 2 is a high-pressure pump (HPP), specifically not a tank pump, and is designed as a piston pump. It includes a piston 10, which serves to pump fuel from a low-pressure side 12 of the fuel pump 2 to a high-pressure side 14. In the variant shown here, the piston 10 is driven by the internal combustion engine 6. The low-pressure side 12 and the high-pressure side 14 are fluidically connected and together form a pump chamber 16 of the fuel pump 2. Fuel is supplied to the fuel pump 2 from a fuel tank 18 via a feed line (not shown in detail here).In addition, a tank pump 19, designed as an electric fuel pump, is arranged. The fuel is then pumped by the periodic movement of the piston 10 during operation, brought to a higher pressure level and supplied to the internal combustion engine 6 via a return line 20 of the fuel pump 2.

[0034] On the side facing away from the combustion engine 6, i.e., at the pump head, the fuel pump 2 has a pressure damper 22, which is in particular part of the low-pressure side 12. This pressure damper 22 is fluidically connected to a mounting-side stepped chamber 24 by means of a transverse bore (not shown here). This makes it possible to use fuel from the low-pressure side 12 for the purpose of lubricating the piston 10.

[0035] In the Fig. In the variant shown in Figure 1, a heat sink 26 is arranged on the side of the fuel pump 2 facing away from the mounting side. In the embodiment shown here, this heat sink is designed as a cap or hood and is specifically mounted on the pressure damper 22. The heat sink 26 comprises a housing 28, which is adapted to fit snugly against the pump head and, in particular, encloses a large part of the low-pressure side 12. A cavity 30 is formed in the housing 28, in which a heat storage medium 32 is arranged. In the variant shown here, the cavity 30 is completely enclosed by the housing 28, so that the heat storage medium 32 does not come into contact with the other parts of the fuel pump 2. The material from which the housing 28 is made also serves, in particular, as insulation and for adjusting the heat transfer to and from the environment.In a variant not shown here, however, it is possible that further, additional insulation is arranged around the heat sink 26.

[0036] In an alternative embodiment, not shown here, the housing 28 is not designed as a cap, but, for example, as a ring with a torus-shaped cavity 30. In another variant, the housing 28 completely covers the remaining fuel pump 2 and extends down to the combustion engine 6.

[0037] To illustrate the thermal dynamics and to explain a method for removing residual heat, the following is shown. Fig. Figure 3 shows a graph in which exemplary temperature profiles TK, TPCM for the fuel and the heat storage medium 32 are plotted against time Z. The vehicle is in operation until time Z0, at which point it is switched off, which also means that the combustion engine 6 and the fuel pump 2 are switched off. Up to time Z0, the vehicle operates in stop-and-go mode, clearly recognizable by the wave-like profile of the fuel temperature TK within the fuel pump 2. During stop phases, the fuel temperature rises, particularly due to insufficient cooling, and drops accordingly during go phases. The heat storage medium 32, on the other hand, undergoes a substantially continuous heating process.

[0038] At time Z0, the vehicle is switched to a shutdown mode, so that in particular, active cooling of the combustion engine 6 and the fuel pump 2 ceases. This is clearly evident from the fact that the fuel temperature TK initially rises starting at time Z0 due to residual heat emitted by the combustion engine 6. For the heat storage medium 32, a decrease in temperature TPCM is initially observed in the case described here, primarily due to the onset of thermalization with the environment and the heat sink 26 being located further away from the combustion engine 6 compared to the pump compartment 16. After a certain period of time, however, for example a few minutes, the temperature TPCM of the heat storage medium 32 also rises.Time Z0 also marks the beginning of a post-heating period N, during which the component temperatures are essentially determined on the one hand by heat absorption from the combustion engine 6 and on the other hand by heat dissipation to the environment. As shown in... Fig. As is clearly evident in Figure 3, at the beginning of the post-heating period N, a hot phase H initially results in increased heating of the fuel pump 2 and the heat storage medium 32, which consequently exceeds the heat dissipation due to thermalization with the environment.

[0039] In the case of a fuel pump 2 without a heat sink 26, the fuel temperature TK would rise to a peak temperature S, which in Fig. Figure 3 is represented by a dashed line depicting the fuel temperature TK. The fuel temperature TK exceeds, in particular, the fuel's evaporation temperature V, which is shown here as a horizontal, dashed line. Within the corresponding dashed section of the fuel temperature TK curve, there is a risk of fuel evaporation. The area F enclosed by the temperature curve TK and the evaporation temperature V essentially represents the amount of energy that must be dissipated to prevent evaporation. The heat of vaporization of the fuel's components is not included here, but is negligible in any case.

[0040] To limit the fuel temperature TK to the evaporation temperature V during the reheating period N, the heat storage medium 32 in the heat sink 26 has a phase transition temperature P, which in the embodiment shown here corresponds to the evaporation temperature V of the fuel. Upon reaching this phase transition temperature P, the heat storage medium 32 is not heated further, but undergoes a phase change. In the case shown here, xylitol is used as the heat storage medium 32, and the phase transition occurs from solid to liquid upon heat input. The phase transition is clearly visible in Fig.Figure 3 shows that the temperature TPCM of the heat storage unit 32 only rises to the phase transition temperature P and then assumes a horizontal profile. The heat extracted in this way does not contribute to heating the fuel, thus effectively limiting the fuel temperature TK to the phase transition temperature P, which then represents a maximum temperature M.

[0041] From a certain point Z1 during the post-heating period N, the heat output from the fuel pump 2 to the environment is significantly greater than the absorption of post-heating heat by the combustion engine 6, and cooling occurs in a cooling phase K following the hot phase H, which begins specifically at time Z1. The drop in temperature at the fuel pump 2 towards an outside temperature A then also allows the heat storage medium 32 to regenerate such that the energy stored therein is also released to the environment. The heat sink 26 then serves primarily as a thermal safety device, similar to an overflow protection system, whereby the heat introduced during the hot phase H is initially stored in the heat storage medium 32 in order to release it again at a later time.Accordingly, during the cooling phase K, the heat storage medium 32 cools below the phase transition temperature P and a corresponding phase transition occurs, so that the heat storage medium 32 is available again for heat absorption during a renewed on- and off-process.

[0042] The three temperatures – evaporation temperature V, phase transition temperature P, and maximum temperature M – do not necessarily have to correspond to the same temperature, as in the embodiment shown here. Rather, it is possible, particularly due to the design, especially because of different spatial arrangements of the heat sink 26 relative to the pump chamber 16 and the combustion engine 6, that certain temperature differences exist, but without adversely affecting the functionality.In particular, in an alternative variant not shown here, the design is such that the phase transition temperature P does not correspond to the evaporation temperature V of the fuel due to the choice of material for the heat storage medium 32, but the maximum temperature M is suitably equal to or lower than the evaporation temperature V, since by means of additional insulation and / or a corresponding spatial arrangement of the heat sink 32 a maximum temperature M that differs from the phase transition temperature P is effectively set. Reference symbol list 2 Fuel pump 4 Fuel line system 6 Internal combustion engine 8 Assembly page 10 pistons 12 Low-pressure side 14 High-pressure side 16 Pump room 18 Fuel tank 19 Tank pump 20 return 22 pressure dampers 24-step room 26 Heat sink 28 cases 30 cavity 32 Heat storage medium Outside temperature F area H Hot phase K Cooling phase N Post-heating period Maximum temperature P Phase transition temperature TK fuel temperature TPCM temperature of the heat storage medium V Evaporation temperature (of the fuel) Z0 Start of shutdown mode Z1 End of hot phase

Claims

[1] Fuel pump (2) which is attached to an internal combustion engine (6) of a vehicle by a mounting side (8) and with a pump chamber (16) through which a fuel flows during operation of the vehicle, wherein a heat sink (26) is arranged, with a heat storage medium (32), wherein the heat sink (26) is designed such that in a shutdown mode of the vehicle during a post-heating period (N) the heating of the fuel due to post-heating heat is limited to a maximum temperature (M), wherein the heat sink (26) is arranged on a side of the fuel pump (2) that is facing away from the mounting side (8). [2] Vehicle component according to the preceding claim, characterized by , that the heat storage medium (32) is a latent heat storage medium. [3] Vehicle component according to any one of the preceding claims, characterized by, that an additive is mixed into the heat storage medium (32) to improve its thermal conductivity. [4] Vehicle component according to any one of the preceding claims, characterized by , that the maximum temperature (M) is a phase transition temperature (P) of the heat storage medium (32) and corresponds at most to an evaporation temperature (V) of the fuel and falls below it by no more than 15 °C. [5] Vehicle component according to any one of the preceding claims, characterized by , that the heat sink (26) is designed as a housing (28) for attachment to the fuel pump (2), and that the housing (28) has a cavity (30) for receiving the heat storage medium (32). [6] Housing (28) configured as a heat sink (26) for a fuel pump (2) according to one of the preceding claims. [7] Method for removing residual heat from a fuel pump (2) of a vehicle, on which a heat sink (26) is arranged, with a heat storage medium (32), wherein in a shutdown mode of the vehicle, the heating of fuel in the fuel pump (2) during a residual heat period is limited to a maximum temperature (M) by absorbing residual heat, wherein the fuel pump (2) is attached to an internal combustion engine (6) of the vehicle with a mounting side (8) and the heat sink (26) is arranged on a side of the fuel pump (2) that is opposite the mounting side (8). [8] Method according to the preceding claim, characterized by , that in a hot phase (H) of the shutdown mode the post-heating heat is absorbed by the heat storage medium (32) and in a cooling phase (K) following the hot phase (H) the heat storage medium (32) is at least partially regenerated by heat release.

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