Waste heat recovery power electronics device cooling

Abstract

A cooling system for an electric vehicle includes a first cooling circuit that circulates coolant to cool at least one of the vehicle's power electronics and a motor / generator. The first coolant circuit includes a heat exchanger for exchanging heat with the coolant in the first cooling circuit. A second cooling circuit is configured to circulate coolant to cool the vehicle's battery. The second cooling circuit includes a coolant cooler connected to the vehicle's refrigeration system to exchange heat received from the battery in the coolant with the vehicle's refrigeration system.

Description

[0001] Declaration on Government Rights

[0002] This invention was carried out with government support through a Department of Energy certificate, DE-EE0007761. The government holds certain rights to this invention.

[0003] Cross-reference to related applications

[0004] This application claims the benefit of a U.S. provisional application serial number filed on November 9, 2018, which is incorporated herein by reference.

[0005] background

[0006] This application relates to apparatus, methods, systems, and techniques for determining and regulating the temperature conditions of one or more electronic components in cooling systems used in electric powertrains, mild hybrid powertrains, and strong hybrid powertrains. Under certain operating conditions, the motors / generators and power electronics in such powertrains can withstand sufficiently warm temperatures that temperature regulation using working fluids near ambient temperature is adequate. However, batteries require temperature regulation for approximately half the duration of normal operating temperature. Therefore, there remains a substantial need for the unique apparatus, methods, systems, and techniques disclosed herein.

[0007] The content of the explanatory implementation plan

[0008] To clearly, concisely, and accurately describe the illustrative embodiments of this disclosure, the manner and procedures for making and using this disclosure, and to enable the practice, making, and use of this disclosure, reference will now be made to certain exemplary embodiments, including those shown in the figures, and this disclosure will be described using specific language. However, it should be understood that this does not constitute any limitation on the scope of the invention, and that the invention includes and protects such changes, modifications, and additional applications of the exemplary embodiments that would occur to those skilled in the art. Summary of the Invention

[0009] Exemplary embodiments include unique devices, methods, systems, and techniques for cooling electric powertrains, mild hybrid powertrains, and strong hybrid powertrains to manage the temperature conditions of one or more electronic components in the system. Further embodiments, forms, objectives, features, advantages, aspects, and benefits should become apparent from the following description and figures. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of one embodiment of an exemplary cooling system for electronic components in an electric powertrain system.

[0011] Figure 2 This is a schematic diagram of the cooling system in another implementation scheme.

[0012] Figure 3 This is a schematic diagram of the cooling system in another implementation scheme.

[0013] Figure 4 This is a schematic diagram of the cooling system in another implementation scheme.

[0014] Figure 5 This is a schematic diagram of the cooling system in another implementation scheme.

[0015] Figure 6 During high-temperature environmental conditions Figure 5 A schematic diagram of the cooling system.

[0016] Figure 7 During low temperature environmental conditions Figure 5 A schematic diagram of the cooling system. Detailed Implementation

[0017] The various cooling systems disclosed herein include arrangements in which separate cooling circuits can be used to cool certain electronic components to improve efficiency. For example, to reduce cooler energy consumption and improve system efficiency, batteries may have a different coolant circuit than motors / generators and power electronics during periods of high environmental conditions.

[0018] refer to Figure 1 The illustration shows an exemplary cooling system 100, including a coolant reservoir 120 that supplies coolant to an external coolant circuit 111 and a fan 124 operable to supply cooling air to a cryogenic radiator 122. The cryogenic radiator 122 lowers the temperature of the coolant in the external coolant circuit 111 and, under certain operating conditions, lowers the temperature of the coolant in an internal coolant circuit 113. The external coolant circuit 111 supplies the lower-temperature coolant from the cryogenic radiator 122 to power electronics 110 and to a motor / generator 112 downstream of power electronics 110. Heat from power electronics 110 and motor / generator 112 is transferred to the coolant in the external coolant circuit 111 and supplied to a pump 132 downstream of motor / generator 112 to circulate through the cryogenic radiator 122, thereby lowering the coolant temperature.

[0019] The internal coolant circuit 113 is flow-connected to the external coolant circuit 111 via a first three-way valve 134 and a second three-way valve 136. Under certain low ambient temperature conditions, coolant from the cryogenic radiator 122 is supplied from the external coolant circuit 111 to the internal coolant circuit 113 via the first three-way valve 134 to circulate through the coolant cooler 126 and the battery cooling plate 118. The coolant, heated by the battery 114, then returns to the external circuit 111 via the second three-way valve 136. Although the discussion herein specifically relates to batteries, any suitable energy storage device for electric powertrain systems can be contemplated, as is known in the art.

[0020] Under high ambient temperature conditions, three-way valves 134 and 136 can be used to isolate the inner circuit 113 from the outer coolant circuit 111, and a second coolant pump 130 can be used to circulate the coolant within the closed inner circuit 113. The coolant chiller 126 is connected to the cabin A / C refrigerant circuit 140, which is fluidly isolated from but thermally connected to the coolant in the inner coolant circuit 113 within the coolant chiller 126. The inner coolant circuit 113 supplies coolant to the battery cooling plate 118 downstream of the coolant chiller 126, which is cooled by the A / C refrigerant circuit 140 during periods of higher ambient temperature. The battery cooling plate 118 can be thermally coupled to the battery 114 via an electric heater 116 between it and the battery 114, but any suitable battery arrangement is contemplated.

[0021] refer to Figure 2 The diagram illustrates a schematic depiction of certain portions of a cooling system 200 according to another embodiment, similar to cooling system 100 except that the cryogenic radiator 122 is replaced by a waste heat recovery system (WHR) 220. The WHR system 220 includes a WHR working fluid 236 that circulates through a WHR heat exchanger 222 and a WHR boiler 234 downstream of the WHR heat exchanger 222. The working fluid 236 is isolated from but thermally connected to the coolant in the external coolant circuit 111 within the WHR heat exchanger 222. The WHR heat exchanger 222 receives heat from the coolant in the external coolant circuit 111 and, under certain low ambient temperature conditions, from the internal coolant circuit 213 to provide a lower-temperature coolant for circulation through the power electronics 110, the motor / generator 112, and the battery 114.

[0022] During periods of higher ambient temperature, the WHR heat exchanger 222 does not supply coolant at a lower temperature to the internal coolant circuit 113. Instead, as described above, the coolant in the internal circuit 113 is flow-isolated from the external circuit 111, and the coolant circulates within the internal circuit 113 and is cooled by the cabin A / C refrigerant circulating through the coolant chiller 126.

[0023] refer to Figure 3 The diagram illustrates another embodiment of a cooling system 300, similar to cooling system 200, except that a second coolant circuit 313 is provided as a separate cooling system 302, which does not share coolant with the external coolant circuit 111 under any operating conditions. Cooling system 302 includes a first coolant reservoir 310 that supplies coolant to the second coolant circuit 313.

[0024] Coolant is supplied from the second coolant reservoir 310 to the second coolant circuit 313. The second coolant circuit 313 supplies coolant to the battery cooling plate 318. The battery cooling plate 318 is thermally coupled to the battery 314 via an electric heater 316 between it and the battery 314. The second coolant circuit 313 then supplies the coolant heated from the battery 314 to a second pump 330 downstream of the battery cooling plate 318. The second pump 330 circulates the heated coolant to a coolant cooler 326 downstream of the second pump 330. Cabin A / C refrigerant 140 is supplied to the coolant cooler 326 via cabin A / C refrigerant circuit 117 to cool the battery cooling plate 318 before the heated coolant is circulated back to it. In this embodiment, the cabin A / C refrigerant provides all the cooling for the battery 314, while... Figure 1 and Figure 2 In the implementation scheme, the cabin A / C refrigerant only provides cooling for the battery during periods of higher ambient temperature.

[0025] refer to Figure 4 The illustration shows a schematic depiction of a cooling system 400 according to another embodiment, which includes a WHR refrigerant 416 and a supply of coolant to a first coolant circuit 411. The first coolant circuit 411 provides coolant to cool power electronic devices 410 and a motor / generator 412, and the heated coolant circulates through a WHR heat exchanger 422. The heated working fluid from the WHR heat exchanger 422 circulates through a WHR boiler 414.

[0026] The cooling system 400 also includes a second coolant circuit 413. The second coolant circuit 413 includes a pump 430 that circulates coolant heated by the battery 414 for cooling by a coolant WHR heat exchanger 422 during lower temperature ambient conditions. The second coolant circuit 413 circulates coolant from the WHR heat exchanger 422 to a coolant cooler 426, and then to a battery cooling plate 418, which is thermally coupled to the battery 414 via an electric heater 416 between itself and the battery 414.

[0027] Depending on the position of the three-way valve 436, the pump 430 circulates coolant to the coolant WHR heat exchanger 422 during low-temperature conditions, or circulates coolant within the second coolant circuit 413 (bypassing the WHR heat exchanger 422) during high-temperature conditions. During lower-temperature conditions, the coolant in the second coolant circuit 413 circulates through the coolant WHR heat exchanger 422 to lower its temperature. During high-temperature conditions, cabin A / C refrigerant 140 is supplied to the coolant chiller 426 via a cabin A / C refrigerant circuit 117 isolated from the second coolant circuit 413 to cool the coolant in the second coolant circuit 413.

[0028] refer to Figure 5 The diagram illustrates a cooling system 500 of another embodiment, comprising a WHR refrigerant 534 supplied from, for example, a supply pump (not shown). The WHR refrigerant 534 is supplied to a WHR refrigerant circuit 515, which, during certain operating conditions, supplies refrigerant to a refrigerant heat exchanger 532 to exchange heat with refrigerant from a coolant cooler 526. The refrigerant circuit 515 then supplies refrigerant to a coolant heat exchanger 530 downstream of the refrigerant heat exchanger 532. The refrigerant circuit 515 then supplies refrigerant to a WHR system 536 downstream of the coolant heat exchanger 530. In one embodiment, the WHR system 536 and... Figures 2 to 4 The WHR system is an organic Rankine cycle WHR system.

[0029] Coolant reservoir 524 supplies coolant to first coolant circuit 511. First coolant circuit 511 includes first pump 528, which circulates coolant through coolant heat exchanger 530, power electronics 510, and motor / generator 512. The coolant in first coolant circuit 511 is isolated from but thermally connected to the WHR refrigerant in refrigerant circuit 515 within coolant heat exchanger 530.

[0030] The first coolant circuit 511 also supplies coolant to a three-way valve 534 located between a first portion 513a and a second portion 513b of a second coolant circuit 513 downstream of the coolant heat exchanger 530. As described below, the positioning of the three-way valve 534 can be used to control whether the coolant from the first circuit 511 circulates in the second coolant circuit 513 to receive heat from the battery 514 and return to the first coolant circuit 511, or circulates in a closed loop within the second coolant circuit 513, partially formed by the second portion 513b, to exchange heat with the refrigerant circulating in the third coolant circuit 519.

[0031] The third coolant circuit 519 provides a coolant flow path from the coolant chiller 526 to the refrigerant heat exchanger 532 during certain operating conditions. For example, as Figure 6 As shown, the improved cooling system 500' is illustrated as having an effective flow path during hotter or higher ambient temperature conditions. In the cooling system 500', a three-way valve 534 and a two-way valve 520 are positioned such that a first coolant or refrigerant circulates through a third coolant circuit 519 and a coolant cooler 526, and that the coolant from the first circuit 511 is recirculated through the coolant cooler 526 in a closed loop formed by a second portion 513a of a second coolant circuit 513 using a pump 538. Therefore, the first coolant circuit 511 is isolated from the third coolant circuit 519 and does not provide coolant for cooling a battery 514, which may include a cooling plate 516 and a heater 518. The refrigerant or coolant in the third coolant circuit 519 receives heat from the battery 514 via heat exchange in the coolant cooler 526 and can be compressed by a compressor 522 in a vapor compression cycle before returning to the refrigerant heat exchanger 532.

[0032] refer to Figure 7 The diagram illustrates an effective coolant flow path for the cooling system 500 during operation at lower ambient temperatures, as shown in Cooling System 500”. Figure 7 In this operation, the two-way valve 520 is closed to prevent circulation through the third coolant circuit 519, and the three-way valve 534 is positioned such that coolant from the first coolant circuit 511 circulates through the coolant cooler 526, receives heat from the battery 514, and returns to the first coolant circuit 511. During this operation, heat from the battery 514 is transferred to the coolant and returned to the coolant heat exchanger 530, instead of as in... Figure 6 In operation, the refrigerant returns to the refrigerant heat exchanger 532 through the third loop 519.

[0033] refer to Figure 1 and Figure 2The implementation scheme can improve cooler energy consumption by isolating the second or internal coolant circuit 113 used for the battery from the first or external coolant circuit 111 used for the motor / generator 112 and power electronics 114 during higher temperature environmental conditions. During warmer ambient temperature conditions, the internal coolant circuit 113 is isolated by utilizing three-way valves 134, 136 and pump 130 to isolate cooling of the battery 114. Figure 3 In one implementation, a separate second cryogenic (lower coolant temperature for cooling) circuit 313 for cooling battery 314 is used in conjunction with a separate first high-temperature (higher coolant temperature for cooling) circuit 111 for power electronics 110 and motor / generator 112. This implementation may have the benefit of reducing the total coolant cooler 326 load from the high-temperature circuit 111, but for the cryogenic circuit 313, it relies solely on the coolant cooler 326, even during colder ambient conditions.

[0034] Figure 2 , Figure 3 , Figure 4 and Figure 5 An implementation scheme using a WHR system is shown. The WHR working fluids 236, 416, 534 exiting the WHR heat exchanger provide heat-absorbing components at near-ambient temperatures within the coolant WHR heat exchangers 222, 422, 532, which can be used without the need for integrated separate cryogenic radiators.

[0035] refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 In one implementation, cabin A / C refrigerant 140 is used to cool areas requiring lower-temperature cooling, such as batteries 114, 314, and 414. These implementations can be modified to include a separate vapor compression cycle, such as cooling system 500, to transfer heat from the battery cooling circuit to another cooling circuit, either a WHR working fluid circuit or a refrigerant coolant circuit, particularly when the ambient temperature is too high for direct cooling with WHR working fluid 534 or a cryogenic coolant.

[0036] According to one aspect of this disclosure, a cooling system for an electric vehicle includes a first cooling circuit and a second cooling circuit. The first cooling circuit circulates coolant to cool at least one of the vehicle's power electronics and a motor / generator. The first cooling circuit includes a heat exchanger for exchanging heat with the coolant in the first cooling circuit. The second cooling circuit circulates coolant to cool the vehicle's energy storage device. The second cooling circuit includes a coolant cooler connected to the vehicle's refrigeration system to exchange heat received from the energy storage device in the coolant with the vehicle's refrigeration system.

[0037] In one embodiment, the heat exchanger is a radiator. In one embodiment, at least one of the first cooling circuit and the second cooling circuit includes a pump for circulating coolant. In one embodiment, each of the first cooling circuit and the second cooling circuit includes a pump for circulating coolant. In one embodiment, the refrigeration system is part of a cabin refrigeration system for the vehicle.

[0038] In one embodiment, the heat exchanger is part of the vehicle's WHR system. In one embodiment, the second cooling circuit is connected to the first cooling circuit via a flow control valve, and in response to a first ambient temperature condition, the flow control valve is positioned to isolate coolant in the second cooling circuit, and in response to a second ambient temperature condition, the flow control valve is positioned to allow coolant to flow from the second cooling circuit to the first cooling circuit.

[0039] In one embodiment, the second cooling circuit is completely separate from the first cooling circuit. In one embodiment, the coolant in the first cooling circuit is in thermal communication with the WHR refrigerant from the WHR system. In one embodiment, the refrigeration system is part of the WHR system and includes a refrigerant heat exchanger, and the refrigerant cooler is connected to the refrigerant heat exchanger via a third cooling circuit.

[0040] In one embodiment, the third cooling circuit includes a compressor for compressing refrigerant from the coolant accelerator. In another embodiment, the third cooling circuit includes a flow control valve to selectively allow refrigerant circulation in the third cooling circuit in response to ambient temperature conditions exceeding a threshold.

[0041] In one embodiment, the second cooling circuit is connected to the first cooling circuit via a second flow control valve, and in response to an ambient temperature condition greater than a threshold for recirculating the coolant in the second cooling circuit, the second flow control valve is configured to isolate the coolant in the second cooling circuit, and in response to an ambient temperature condition less than the threshold, the second flow control valve is configured to allow coolant to flow from the first cooling circuit through the second cooling circuit and the coolant cooler and back to the first cooling circuit.

[0042] According to another aspect, a method for operating a cooling system of an electric vehicle includes: circulating a coolant in a first cooling circuit to cool at least one of the vehicle's power electronics and a motor / generator, wherein the first cooling circuit includes a heat exchanger for exchanging heat with the coolant in the first cooling circuit; and circulating the coolant in a second cooling circuit to cool an energy storage device of the vehicle, wherein the second cooling circuit includes a coolant cooler connected to the vehicle's refrigeration system to exchange heat received from the energy storage device in the coolant with the vehicle's refrigeration system.

[0043] In one embodiment, the method includes: in response to a first ambient temperature condition, positioning a flow control valve connecting a second cooling circuit to a first cooling circuit to isolate coolant in the second cooling circuit; and in response to a second ambient temperature condition, positioning the flow control valve to allow coolant to flow from the second cooling circuit to the first cooling circuit.

[0044] In one embodiment, the second cooling circuit is completely separate from the first cooling circuit, and the coolant in the first cooling circuit is in thermal communication with the WHR refrigerant from the vehicle's WHR system. In one embodiment, the refrigeration system is part of the WHR system and includes a refrigerant heat exchanger, and the refrigerant cooler is connected to the refrigerant heat exchanger via a third cooling circuit.

[0045] In one embodiment, the third cooling circuit includes a compressor for compressing refrigerant from the coolant accelerator and a flow control valve for selectively allowing the circulation of refrigerant in the third cooling circuit in response to ambient temperature conditions exceeding a threshold.

[0046] In one embodiment, the method includes: in response to an ambient temperature condition greater than a threshold for recirculating coolant in the second cooling circuit, positioning a second flow control valve connecting the second cooling circuit to the first cooling circuit to isolate coolant in the second cooling circuit. The method further includes: in response to an ambient temperature condition less than the threshold, positioning the second flow control valve to allow coolant to flow from the first cooling circuit through the second cooling circuit and the coolant cooler and back to the first cooling circuit.

[0047] In one embodiment, the refrigeration system is part of the cabin refrigeration system for the vehicle.

[0048] This disclosure also envisions that an electronic control device could be used to operate the system and / or to perform the methods disclosed herein.

[0049] Although illustrative embodiments of the present disclosure have been shown and described in detail in the accompanying drawings and the foregoing description, this is to be considered illustrative rather than restrictive in nature. It should be understood that only certain exemplary embodiments have been shown and described, and all changes and modifications falling within the spirit of the claimed invention are protected. It should be understood that although the use of words such as preferred, preferred, or more preferred in the above description indicates that such described features may be more desirable, but may not be necessary, and embodiments lacking said features are conceivable within the scope of the invention, defined by the appended claims. When reading the claims, it is intended that the use of words such as “a,” “an,” “at least one,” or “at least a portion” is not intended to limit the claim to only one item unless explicitly stated otherwise in the claims. When the language “at least a portion” and / or “a portion” is used, an item may include a portion and / or the entire item unless explicitly stated otherwise. Non-limiting examples of content that may be claimed in one or more non-provisional applications claiming priority to this application include the following.

Claims

1. A cooling system for an electric vehicle, the system comprising: a first cooling circuit for circulating coolant to cool at least one of power electronics and a motor / generator of the vehicle, wherein the first cooling circuit includes a heat exchanger for exchanging heat with the coolant in the first cooling circuit; and a second cooling circuit for circulating coolant to cool an energy storage device of the vehicle, wherein the second cooling circuit includes a coolant chiller connected to a refrigeration system of the vehicle to exchange heat in the coolant received from the energy storage device with the refrigeration system of the vehicle, wherein the second cooling circuit is connected to the first cooling circuit by a flow control valve and the flow control valve is positionable to isolate the coolant in the second cooling circuit in response to a first ambient temperature condition and to allow coolant to flow from the second cooling circuit to the first cooling circuit in response to a second ambient temperature condition.

2. The cooling system of claim 1, wherein the heat exchanger is a radiator.

3. The cooling system of claim 1, wherein at least one of the first cooling circuit and the second cooling circuit includes a pump for circulating coolant.

4. The cooling system of claim 1, wherein each of the first cooling circuit and the second cooling circuit includes a pump for circulating coolant.

5. The cooling system of claim 1, wherein the heat exchanger is part of a waste heat recovery system of the vehicle.

6. The cooling system of claim 5, wherein the second cooling circuit is completely separate from the first cooling circuit.

7. The cooling system of claim 5, wherein the coolant in the first cooling circuit is in thermal communication with a waste heat recovery refrigerant from the waste heat recovery system.

8. The cooling system of claim 5, wherein the refrigeration system is part of the waste heat recovery system and includes a refrigerant heat exchanger, and the coolant chiller is connected to the refrigerant heat exchanger by a third cooling circuit.

9. The cooling system of claim 8, wherein the third cooling circuit includes a compressor for compressing refrigerant from the coolant chiller.

10. The cooling system of claim 8, wherein the third cooling circuit includes a flow control valve for selectively allowing circulation of refrigerant in the third cooling circuit in response to an ambient temperature condition that is greater than a threshold value.

11. The cooling system of claim 10, wherein the second cooling circuit is connected to the first cooling circuit by a second flow control valve and, in response to the ambient temperature condition being greater than a threshold for recirculating coolant in the second cooling circuit, the second flow control valve is positionable to isolate the coolant in the second cooling circuit and, in response to the ambient temperature condition being less than the threshold, the second flow control valve is positionable to allow coolant to flow from the first cooling circuit through the second cooling circuit and the coolant chiller and back to the first cooling circuit.

12. The cooling system of claim 1, wherein the refrigeration system is part of a passenger cabin refrigeration system for the vehicle.

13. A method for operating an electric vehicle cooling system, comprising: circulating coolant in a first cooling circuit to cool at least one of power electronics and a motor / generator of the vehicle, wherein the first cooling circuit includes a heat exchanger for exchanging heat with coolant in the first cooling circuit; circulating coolant in a second cooling circuit to cool an energy storage device of the vehicle, wherein the second cooling circuit includes a coolant chiller connected to a refrigeration system of the vehicle to exchange heat in the coolant received from the energy storage device with the refrigeration system of the vehicle, in response to a first ambient temperature condition, positioning a flow control valve connecting the second cooling circuit to the first cooling circuit to isolate coolant in the second cooling circuit; and in response to a second ambient temperature condition, positioning the flow control valve to allow coolant to flow from the second cooling circuit to the first cooling circuit.

14. The method of claim 13, wherein the second cooling circuit is completely separate from the first cooling circuit and coolant in the first cooling circuit is in thermal communication with waste heat recovery refrigerant from a waste heat recovery system of the vehicle.

15. The method of claim 14, wherein the refrigeration system is part of the waste heat recovery system and includes a refrigerant heat exchanger and the coolant chiller is connected to the refrigerant heat exchanger by a third cooling circuit.

16. The method of claim 15, wherein the third cooling circuit includes: a compressor for compressing refrigerant from the coolant chiller; and a flow control valve for selectively allowing circulation of refrigerant in the third cooling circuit in response to an ambient temperature condition being greater than a threshold.

17. The method of claim 16, further comprising: in response to the ambient temperature condition being greater than a threshold for recirculating coolant in the second cooling circuit, positioning a second flow control valve connecting the second cooling circuit to the first cooling circuit to isolate coolant in the second cooling circuit; and ​ responsive to the ambient temperature condition being less than the threshold value, positioning the second flow control valve to allow coolant to flow from the first cooling circuit, through the second cooling circuit and the coolant chiller, and back to the first cooling circuit.

18. The method of claim 13, wherein the refrigeration system is part of a passenger cabin refrigeration system for the vehicle.

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