Method for buffering waste heat of a refrigerant circuit as part of an indirect heat-transport-medium circuit system of an electric vehicle
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-02-09
- Publication Date
- 2026-08-13
Smart Images
Figure DE2026100148_13082026_PF_FP_ABST
Abstract
Description
[0001] Description
[0002] METHOD FOR BUFFING WASTE HEAT FROM A REFRIGERANT CIRCUIT AS PART OF AN INDIRECT HEAT TRANSPORTATION CIRCUIT SYSTEM OF AN ELECTRIC VEHICLE
[0003] The invention relates to a method for buffering waste heat from a
[0004] A cold medium circuit as part of an indirect heat transfer medium circuit system of an electric vehicle. In this context, one can also speak of a method for avoiding thermally induced switching on and off of such a compressor.
[0005] Such an indirect heat transfer medium circuit system is also referred to as an indirect thermal management system or heat management system.
[0006] The invention also relates to a computer program product representing this method, a computer-readable storage medium on which this computer program product is stored, a control unit, a thermo module, a vehicle or electric vehicle, and an indirect heat transfer medium circuit system.
[0007] Electric vehicles require so-called intelligent thermal management, which operates individual components of the electric vehicle within an assigned optimal temperature range.
[0008] The switching off and on again, or the switching on and off of a compressor in such a refrigerant circuit, describes a so-called...
[0009] Compressor cycle, also referred to as a compressor cycle or compressor phase. Therefore, the proposed method can also be described as avoiding compressor cycles. These cycles or phases of the compressor are generally necessary to regulate desired or set temperatures and thereby save energy.
[0010] In general, the following applies: If the temperature set for a consumer using such a cold intermediate circuit exceeds a definable or desired temperature value for that consumer, the compressor of the cold intermediate circuit switches on to cool that consumer, for example, a vehicle cabin. And as soon as the desired temperature of the consumer is reached, the compressor switches off again to save energy.
[0011] With regard to such a cold intermediate circuit of an electric vehicle, such a compressor is designed with a view to the largest possible load or stress that may occur. Such a load typically occurs during so-called fast charging of a battery under hot ambient conditions.
[0012] Consequently, the cold intermediate circuit delivers too much power at low loads – and even at minimum speed – of the compressor.
[0013] Energy is consumed, so that the compressor has to be switched off and then on again repeatedly due to waste heat generated by the cold central circuit.
[0014] This is accompanied by undesirable noise and also reduces the compressor's lifespan.
[0015] The object of the present invention is to improve and further develop such thermal management.
[0016] This problem is solved by a method proposed and protected according to claim 1 for avoiding such compressor cycles. According to the invention, the wording – for buffering waste heat – refers to storing this waste heat by a consumer in the form of the battery or vehicle battery and / or at least one component of the electric drive train, or to dissipating this waste heat to this or these consumers.
[0017] However, this wording also implies avoiding or at least reducing such thermally induced compressor cycles or this thermally induced switching off and on of the compressor.
[0018] The proposed method allows a compressor to be operated at a more favorable operating point and thus more efficiently.
[0019] The proposed method also makes it possible to reduce unwanted noise from such a compressor to a minimum.
[0020] Furthermore, the proposed method helps to increase the service life of such a compressor.
[0021] And the larger the thermal mass of the battery and / or at least one component of the electric powertrain, the higher its thermal storage capacity or buffering effect, which should be utilized.
[0022] In particular, a vehicle battery with a large thermal mass proves to be advantageous for the proposed operating method.
[0023] Procedure.
[0024] In one embodiment, the valve system is configured such that the liquid heating circuit is also routed via a first (front) radiator and / or a second (front) radiator for heat exchange between the liquid circuit system and the vehicle environment. This delays or postpones the process of exhausting the thermal storage capacity of the battery and / or at least one component of the electric powertrain.
[0025] In another version, the valve system is set up in such a way that the liquid heating circuit is also or additionally routed via a first heat exchanger to heat a vehicle cabin.
[0026] This allows the electric vehicle's air conditioning system to activate a so-called reheat mode. This is an operating mode in which the air conditioning system not only cools but also heats the air flowing into the vehicle cabin. This allows the humidity and temperature in the vehicle cabin to be regulated or set.
[0027] In another version, once the battery's thermal storage capacity is exhausted, the valve system is adjusted so that a liquid cooling circuit – routed via an evaporator of the refrigerant circuit – is directed over the battery to heat or cool it. For this purpose, the liquid heating circuit can be routed over the first (front) radiator and / or the second (front) radiator.
[0028] In another version, the valve system is adjusted so that the liquid cooling circuit is also or additionally routed via a second heat exchanger to cool the vehicle cabin.
[0029] In this context, reference is made to the previously described reheat mode.
[0030] Furthermore, a computer program product is proposed, comprising instructions that, when executed by a computer, cause it to perform the procedure of the type described above. A computer-readable storage medium is also proposed, comprising instructions that, when executed by a computer, cause it to perform the procedure of the type described above.
[0031] Furthermore, a control unit for a thermomodule is proposed, comprising a computer-readable storage medium of the type described above, on which the computer program product of the type described above is stored, wherein the control unit is received by a housing of the thermomodule or arranged at a distance from the housing of the thermomodule.
[0032] Furthermore, a thermomodule for an indirect heat transfer medium circuit system is proposed, comprising:
[0033] a multi-part housing that accommodates at least two electric liquid pumps;
[0034] of which at least one first liquid pump for operating a liquid cooling circuit - guided via an evaporator of a refrigerant circuit and
[0035] at least one second liquid pump is provided for operating a liquid heating circuit (run) that is routed via a condenser of the refrigerant circuit;
[0036] an electrically adjustable valve system incorporated through the housing, through which, in conjunction with a multitude of liquid channel sections formed in the housing, corresponding liquid circuits of the indirect heat transfer medium circuit system can be adjusted,
[0037] as well as
[0038] a control unit of the type described above for adjusting the thermo module.
[0039] Furthermore, a vehicle or electric vehicle with a control unit of the type described above is proposed. An indirect heat transfer medium circuit system for an electric vehicle is also proposed, wherein the heat transfer medium circuit system includes a control unit of the type described above. Such an indirect heat transfer medium circuit system is also referred to as an indirect thermal management system.
[0040] The invention will now be explained in detail with reference to the figures. Further advantageous embodiments of the invention will become apparent from the dependent claims and the subsequent description of preferred embodiments. These are shown schematically and functionally:
[0041] Fig. 1 shows an indirect heat transfer medium circuit system of an electric vehicle in a first operating mode and
[0042] Fig. 2 shows the heat transfer medium circuit system shown in Fig. 1 in a second operating mode.
[0043] The indirect heat transfer medium circuit system 2 - also called thermal management system or heat management system - according to Figs. 1 and 2 of an electric vehicle has a refrigerant circuit 4 that is dimensioned as small or compactly as possible and a liquid circuit system 6, which is thermally connected to the refrigerant circuit 4 via a first heat exchanger 8 in the form of an evaporator - for the cold section of the refrigerant circuit 4 - and a second heat exchanger 10 in the form of a condenser - for the hot section of the refrigerant circuit 4.
[0044] The refrigerant circuit 4 – also referred to as CRU (Compact Refrigerant Unit) – comprises, in addition to the two heat exchangers 8 and 10, a compressor K for circulating a refrigerant and an expansion valve. Furthermore, at least one pressure sensor and at least one temperature sensor are provided or arranged in the refrigerant circuit 4 upstream and downstream of the compressor K. Additionally, at least one further pressure sensor and one further temperature sensor can be provided or arranged between the expansion valve and the heat exchanger 10.
[0045] In such an indirect heat transfer medium circuit system 2, heat or energy can be transported or distributed indirectly, i.e., indirectly via the liquid circuit system 6 to the individual heat sinks of the electric vehicle.
[0046] In this process, heat and energy distribution can largely be implemented via the liquid cycle system 6, i.e., based on a liquid, for example in the form of a water-glycol mixture.
[0047] This has the advantage that the refrigerant circuit or the CRU (Compact Refrigerant Unit) can be greatly simplified and designed to be very compact or as small as possible. Consequently, the amount of refrigerant used, whether a synthetic refrigerant like R134a or R1234yf, or a natural refrigerant like R744 or R290, can be reduced to a minimum.
[0048] Thus, such a heat transfer medium circuit system 2 contributes to saving weight and costs.
[0049] The fluid circuit system 6 features a proposed thermomodule TM with an electrically adjustable valve system (not illustrated), which allows for the selective and energy-efficient setting of various heating scenarios or heating modes as well as cooling scenarios or cooling modes.
[0050] This thermomodule TM has a multi-part housing to which the electric vehicle's heat sources and heat sinks are connected via fluid lines – for example, in the form of hoses and / or pipes – that are linked to the housing (see connections Ai to A14). Connections Ar, As 1 and A 1 In contrast, these are connections that are provided, arranged, or formed within the housing of the thermomodule TM. This housing of the thermomodule TM is schematically illustrated as a rectangle in Figures 1 and 2.
[0051] By means of the valve system of the thermomodule TM, in conjunction with a large number of liquid channel sections formed in the housing of the thermomodule TM, corresponding liquid circuits of the heat transfer medium circuit system 2 can be adjusted as required.
[0052] The heat sources and heat sinks of the electric vehicle include a first heat exchanger 12 (also called HVAC heater; HVAC
[0053]
[0054] Heating, Ventilation and Air Conditioning) for heating a vehicle cabin (not shown), a second heat exchanger 14 (also called HVAC Cooler) for cooling the vehicle cabin, a first radiator 16 for heat exchange with an environment, at least one component of an electric powertrain 18, a second radiator 20 for heat exchange with the environment (optionally or as required) via a proportional valve P, a battery B, and the evaporator 8 as well as the condenser 10 of the CRU (Compact Refrigerant Unit).
[0055] The aforementioned at least one component of the electric powertrain 18 shall be understood to mean at least one electric motor or e-motor for driving the electric vehicle and at least one power electronics, for example in the form of an inverter, an on-board charger (OBC), a DC-DC converter and / or possibly in the form of at least one further control unit in the form of a high-performance computer.
[0056] The fluid circuit system 6 also includes a heating element HE, located approximately downstream of the capacitor 10, which can be activated to heat the pumped fluid as needed. This heating element HE can, for example, be housed within an associated fluid line section and located between the capacitor 10 and connection A4, i.e., outside the housing of the thermomodule TM. Alternatively, or in addition, such a heating element HE can also be housed within the thermomodule TM and be located on or at least partially within the housing.
[0057] The housing of the thermomodule TM is designed in the form of a multi-part housing with liquid-carrying channels, through which, in addition to the valve system, a first electric liquid pump EWP1 for pumping liquid in a liquid cooling circuit KK of the liquid circuit system 6 and a second electric liquid pump EWP2 for pumping liquid in a liquid heating circuit HK of the liquid circuit system 6 are accommodated.
[0058] This housing of the thermomodule TM also accommodates a third electric liquid pump EWP3, by means of which liquid can be pumped in a liquid circuit via a battery B.
[0059] The heat transfer medium circuit system 2 also includes a large number of temperature sensors, whereby each heat source and each heat sink - for example in relation to an associated liquid pipe section - is or can be assigned at least one temperature sensor in order to be able to detect or determine a temperature of a liquid flowing around and / or through the heat source / heat sink.
[0060] Battery B can be thermally connected to the liquid circuit system 6 indirectly via at least one coupling element, for example, in the form of a plate-like coupling element, wherein the coupling element, located on battery B, is through which and / or around which the liquid of the liquid circuit system 6 flows. Additionally or alternatively, battery B itself can also be supplied with a liquid, such as the aforementioned liquid of the liquid circuit system 6 itself and / or a separate liquid, whereby in the latter case battery B has its own liquid circuit, which as such is thermally connected to the liquid circuit system 6 via an associated heat exchanger.
[0061] The operating method or process underlying the invention is explained below:
[0062] For clarity, Figures 1 and 2 illustrate a liquid cooling circuit (CC) with dashed lines and a liquid heating circuit (HC) with solid lines. This makes it easier to distinguish between these two liquid circuits.
[0063] Fig. 1 illustrates a first operating mode of the system 2, in which the - not illustrated - valve system of the thermomodule TM is set such that the liquid heating circuit HK is routed via the heat exchanger 12, the at least one component of the electric drive train 18, the radiator 16, - if required or optionally or possibly also via - the radiator 20 and the battery B.
[0064] The radiator 16 can, for example, be fluidically connected upstream of the battery B and fluidically connected downstream of the radiator 20 or the component of the electric drive train 18 (Fig. 1).
[0065] The liquid pump EWP2 and the liquid pump EWP3 are connected fluidically in series with each other.
[0066] In this process, waste heat from the refrigerant circuit 4 is transferred to all these consumers or heat sinks until the thermal storage capacity of the battery B is reached or exhausted. The battery B has a high thermal mass, which is advantageously utilized here to avoid thermally induced switching on and off, i.e., cycling, of the compressor K. In this configuration of the thermomodule TM's valve system (according to Fig. 1), the liquid cooling circuit KK is routed via the heat exchanger 14. This liquid cooling circuit KK can optionally be interrupted if the vehicle cabin (not shown) does not require cooling. This option is illustrated by a shut-off valve, which can be implemented, adjusted, or controlled by the thermomodule's valve system in this liquid cooling circuit KK.
[0067] Fig. 1 therefore illustrates, with the liquid heating circuit HK shown, a heating of the battery B, the - not shown - vehicle cabin and at least one component of the electric powertrain 18.
[0068] Figure 2, however, illustrates a second operating mode – namely, after the thermal storage capacity of battery B has been exhausted – in which the (not illustrated) valve system of the thermomodule TM is set such that the liquid cooling circuit KK is routed via battery B and, if necessary, optionally, or possibly, also via the heat exchanger 14. This option is illustrated by a shut-off valve, which can be implemented, adjusted, or controlled by the thermomodule's valve system in this liquid cooling circuit KK.
[0069] The liquid pump EWPi and the liquid pump EWP3 are connected fluidically in series with each other.
[0070] Figure 2 illustrates the cooling of the battery B and the vehicle cabin (not shown) using the liquid cooling circuit KK. This cooling is achieved via radiator 16 and, if necessary, optionally, or additionally via radiator 20. This delays the depletion of the thermal storage capacity of the battery B, thus preventing thermally induced switching on and off of the compressor K for as long as possible. In Figures 1 and 2, the vehicle cabin (not shown) is both heated and cooled to ensure a comfortable interior climate, for example, in situations where the outside temperature is low and the cabin should not be cooled too much.
[0071] By alternately using these two modes shown, it is possible to avoid switching the compressor K off and on again, or at least to reduce the frequency or number of such cycles to a minimum.
[0072] This also minimizes unwanted noise emissions from such a compressor K. Consequently, this proposed operating method contributes to extending the service life of such a compressor K.
[0073] The previously described method is implemented by a computer program. This computer program includes instructions that, when executed by a computer, cause it to carry out the method as described above.
[0074] This computer program product is stored on a computer-readable storage medium or data carrier, which as such comprises instructions which, when the program is executed by the computer, cause it to perform the procedure of the type described above.
[0075] This method is based on sensor-based monitoring of the liquid circuit system, which has a number of temperature and pressure sensors.
[0076] A control unit for the thermomodule TM incorporates such a storage medium or data carrier. This control unit can be integrated into the housing of the thermomodule TM or positioned at a distance from the housing of the thermomodule TM.
[0077] This control unit also includes a digital microprocessor unit (CPU) connected to a bus system and a working memory (RAM). The CPU is designed to execute instructions that are stored as a program in a higher-level memory system or on the aforementioned storage medium or data carrier, to acquire input signals from the data bus, and to output signals to the data bus. The memory system and / or the aforementioned storage medium or data carrier can be various storage media in the form of magnetic, solid-state, and other non-volatile media on which a corresponding computer program or...
[0078] The computer program product for carrying out the proposed procedure and its advantageous configurations is stored.
[0079] At this point, it is clarified that the previously used notation of terms with brackets, such as liquid circuit system, refrigerant circuit, etc., is intended to cover possible alternative designations that, as such, each describe the same thing (e.g., refrigerant circuit = refrigerant circuit; liquid circuit system = liquid circuit system).
[0080] Although the preceding description explains exemplary embodiments, it should be noted that a multitude of variations are possible. Furthermore, it should be emphasized that the exemplary embodiments are merely examples and are not intended to restrict the scope of protection, applications, or structure in any way. Rather, the preceding description provides the skilled person with a guideline for implementing at least one exemplary embodiment, whereby various modifications, particularly with regard to the function and arrangement of the described components, can be made without departing from the scope of protection as defined by the claims and these equivalent combinations of features.
Claims
Patent claims 1. Method for buffering waste heat from a cold medium circuit (4) as part of an indirect heat transfer medium circuit (2) of an electric vehicle, wherein the heat transfer medium circuit (2) has, in addition to the refrigerant circuit (4), a liquid circuit (6) thermally connected to the cold medium circuit (4); wherein an electrically adjustable valve system of a liquid-carrying thermomodule (TM) of the liquid circuit system (6) is set such that the waste heat of the refrigerant circuit (4) is supplied via a liquid heating circuit (HK) of a battery (B) and / or at least one component of an electric powertrain (18) of the electric vehicle by utilizing its thermal storage capacity in order to avoid thermally induced switching off and on of the compressor (K).
2. Method according to claim 1, wherein the valve system is adjusted such that the liquid heating circuit (HC) is also routed via a first radiator (16) and / or second radiator (20) for the exchange of heat between the liquid heating circuit (HC) system (6) and a vehicle environment.
3. Method according to claim 1 or 2, wherein the valve system is adjusted such that the liquid heating circuit (HC) is also routed via a first heat exchanger (12) to heat a vehicle cabin.
4. A method according to any one of the preceding claims, wherein – after the thermal storage capacity of the battery (B) has been exhausted – the valve system is adjusted such that a liquid cooling circuit (CC) – which is routed via an evaporator (8) of the refrigerant circuit (4) – is routed over the battery (B) to cool the battery (B).
5. A method according to claim 4, wherein the valve system is adjusted such that the liquid cooling circuit (CC) is also routed via a second heat exchanger (14) to cool the vehicle cabin.
6. Computer program product comprising instructions which, when the program is executed by a computer, cause it to execute the method according to any one of claims 1 to 5.
7. Computer-readable storage medium comprising instructions which, when executed by a computer, cause the computer to execute the method according to any one of claims 1 to 5.
8. Control unit for a thermomodule (TM) according to one of claims 1 to 5, comprising a computer-readable storage medium according to claim 7, on which the computer program product according to claim 6 is stored, wherein the control unit is received by a housing of the thermomodule (TM) or is arranged spaced apart from the housing of the thermomodule (TM).
9. Thermomodule (TM) for an indirect heat transfer medium circuit system (2) according to one of claims 1 to 5, comprising: a multi-part housing through which at least two electric liquid pumps (EWPi, EWP2) are accommodated; of which at least one first liquid pump (EWP1) for operating a liquid cooling circuit (CC) guided via an evaporator (8) of a refrigerant circuit (4) and at least one second liquid pump (EWP2) is provided for operating a liquid heating circuit (HK) which is routed via a condenser (10) of the refrigerant circuit (4); an electrically adjustable valve system received through the housing, by which, in conjunction with a plurality of liquid channel sections formed in the housing, corresponding liquid circuits of the indirect heat transfer medium circuit system (2) according to one of claims 1 to 5 are adjustable, as well as a control unit according to claim 8 for adjusting the thermomodule (TM).
10. Vehicle with a control unit according to claim 8.
11. Indirect heat transfer medium circuit system (2) for an electric vehicle, wherein the heat transfer medium circuit system (2) comprises a control unit according to claim 8.