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EP-4299346-B1 - AIR CONDITIONING SYSTEM WITH HIGH CAPACITY CENTRIFUGAL REFRIGERANT COMPRESSOR

EP4299346B1EP 4299346 B1EP4299346 B1EP 4299346B1EP-4299346-B1

Inventors

  • MEHTA, DARIUS
  • CADLE, ROBERT

Dates

Publication Date
20260506
Application Date
20230601

Claims (15)

  1. An electric vehicle thermal management system comprising: a user interface for receiving a HVAC setting; a centrifugal compressor (210) for compressing a low pressure refrigerant in a refrigerant loop (130, 320) to generate a high pressure refrigerant; an expansion valve (134) for reducing a pressure of the high pressure refrigerant in the refrigerant loop (130, 320) to generate the low pressure refrigerant; a heat exchanger (310) coupled to the refrigerant loop (130, 320), a battery coolant loop (330) and a cabin coolant loop (110, 340); and a processor for detecting a battery cooling condition, routing one of the low pressure refrigerant and the high pressure refrigerant to the heat exchanger (310) in response to the battery cooling condition, wherein routing one of the low pressure refrigerant and the high pressure refrigerant to the heat exchanger in response to the battery cooling condition includes routing one of the high pressure refrigerant and the low pressure refrigerant to the heat exchanger (310) via a first reversing valve (215) or via the first reversing valve (215) and a second reversing valve (225), regulating the transfer of heat between the refrigerant loop (130, 320) and the battery cooling loop (330) in response to a temperature of the battery coolant within the battery cooling loop and the battery cooling condition, and regulating the transfer of heat between the battery coolant loop (330) and a cabin coolant loop (110, 340) in response to the HVAC setting and a cabin coolant temperature within the cabin coolant loop.
  2. The electric vehicle thermal management system of claim 1, wherein the processor is further operative for isolating a cabin portion of the cabin coolant loop (340) from a heat exchanger portion (250) of the cabin coolant loop in response to the cabin coolant temperature being less than a threshold temperature wherein the threshold temperature is determined in response to the HVAC setting and a vehicle cabin temperature, and activating a coolant heater (352) within the cabin portion of the cabin coolant loop in response to the HVAC setting and the cabin coolant temperature being less than the threshold temperature.
  3. The electric vehicle thermal management system of any preceding claim, wherein the low pressure refrigerant is routed to the heat exchanger (310) in response to the battery cooling condition being a cooling condition and wherein the high pressure refrigerant is routed to the heat exchanger (310) in response to the battery cooling condition being a heating condition.
  4. The electric vehicle thermal management system of any preceding claim, wherein the cabin coolant temperature is measured within the cabin portion of the cabin coolant loop (340).
  5. The electric vehicle thermal management system of any preceding claim, wherein the transfer of heat between the refrigerant loop (320) and the battery cooling loop (330) is performed by regulating a speed of a battery coolant pump (335).
  6. The electric vehicle thermal management system of any preceding claim, wherein the transfer of heat between the cabin coolant loop (110, 340) and the battery cooling loop is performed by regulating a speed of a cabin coolant pump (354).
  7. The electric vehicle thermal management system of any preceding claim, further including a heater core coupled to the cabin coolant loop (110, 340) for exchanging heat between the cabin coolant and a vehicle cabin (171).
  8. The electric vehicle thermal management system of any preceding claim, wherein the battery cooling condition is determined in response to a charging state of a battery.
  9. The electric vehicle thermal management system of any preceding claim, wherein the battery cooling condition is determined in response to a battery temperature.
  10. A method comprising: compressing a low pressure refrigerant with a centrifugal compressor (210) to generate a high pressure refrigerant; determining a battery cooling condition; routing one of the low pressure refrigerant and the high pressure refrigerant to the heat exchanger in response to the battery cooling condition, wherein routing one of the low pressure refrigerant and the high pressure refrigerant to the heat exchanger in response to the battery cooling condition includes routing one of the high pressure refrigerant and the low pressure refrigerant to the heat exchanger (310) via a first reversing valve (215) or via the first reversing valve (215) and a second reversing valve (225); regulating a transfer of heat between the refrigerant loop and the battery cooling loop in response to a temperature of the battery coolant within the battery cooling loop and the battery cooling condition; and regulating the transfer of heat between the battery coolant loop and a cabin coolant loop (340) in response to the HVAC setting and a cabin coolant temperature within the cabin coolant loop.
  11. The method of claim 10, further including: isolating a cabin portion of the cabin coolant loop (340) from a heat exchanger portion of the cabin coolant loop in response to the cabin coolant temperature being less than a threshold temperature wherein the threshold temperature is determined in response to the HVAC setting and a vehicle cabin temperature; and activating a coolant heater (352) within the cabin portion of the cabin coolant loop in response to the HVAC setting and the cabin coolant temperature being less than the threshold temperature.
  12. The method of claim 10 or 11, wherein the low pressure refrigerant is coupled to the heat exchanger (310) for cooling the battery and the high pressure refrigerant is coupled to the heat exchanger for warming the battery, and / or wherein a rotational speed of the centrifugal compressor (210) is regulated in response to the battery cooling condition, and / or wherein the battery cooling condition is determined in response to an ambient temperature.
  13. The method of claim 10, 11 or 12, wherein the transfer of heat between the battery coolant loop (330) and a cabin coolant loop (340) is regulated by varying a flow rate of a cabin coolant pump, and / or wherein the transfer of heat between the refrigerant loop (320) and the battery cooling loop (330) is regulated by varying a flow rate of a battery coolant pump, and / or wherein the transfer of heat between the battery cooling loop (330) and a vehicle cabin is regulated by varying a flow rate of a battery coolant pump (335) and a speed of a vehicle cabin fan.
  14. The electric vehicle thermal management system of claim 1, further comprising: a valve for coupling one of the high pressure refrigerant and the low pressure refrigerant to the heat exchanger via the refrigerant loop in response to a valve control signal; a battery coolant pump (335) for regulating the flow of a battery coolant in response to a battery coolant pump control signal; a cabin coolant pump (354) for regulating the flow of a cabin coolant in response to a cabin coolant pump control signal; and wherein the processor is configured to determine the battery cooling condition also on the basis of a battery temperature, wherein the processor is configured to generate the valve control signal and the battery coolant pump control signal in response to the battery cooling condition and the battery temperature, and to generate the cabin coolant pump control signal in response to the HVAC setting and the cabin coolant temperature.
  15. The system of claim 14, wherein the system further comprises: a bypass valve (118) for isolating a cabin portion of the cabin coolant loop from a heat exchanger portion of the cabin coolant loop in response to the cabin coolant temperature being less than a threshold temperature wherein the threshold temperature is determined in response to the HVAC setting; and a coolant heater within the cabin portion of the cabin coolant loop for heating the cabin coolant in response to the cabin coolant temperature being less than the threshold temperature.

Description

TECHNICAL FIELD The present disclosure generally relates to an electric vehicle air conditioning system and, more particularly, relates to an integrated electric vehicle battery and cabin air conditioning system employing a high capacity centrifugal refrigerant compressor to compress refrigerant for heating and cooling of an electric vehicle battery and a vehicle cabin. BACKGROUND Electric vehicles are now becoming more and more common in the passenger vehicle marketplace. A barrier to widespread adoption of electric vehicles is that a vehicle's range is limited by its battery capacity. As electrical vehicles take longer to recharge than combustion engine vehicles take to fill a fuel tank, this extra charging time may discourage some people from purchasing an electrical vehicle. As more features and/or increased vehicle range require more battery capacity, it is desirable to be able to recharge the batteries as quickly as possible to allow for vehicle trips longer than the range of one battery charge. Increased battery capacity, along with increased battery discharge rates and increased DC fast charging rates result in increased heat generated during fast battery charging and discharge. Newly introduced "extreme" fast charging levels will soon be 300+ kWdc. The vehicles being charged will require enhanced cooling systems to reduce the heat generated during the "extreme" fast charging operations. In addition, as more and more features are added to an electric vehicle, such as heating and cooling, safety features, infotainment and communications features, autonomous driving vehicle controllers and the like, the need for enhanced cooling will also be required during vehicle operation. Currently to meet the demand for electric vehicle cooling, conventional scroll type air conditioning (AC) compressors are used. These scroll type AC compressors suffer from excessive noise, vibration, and harshness (NVH) levels. As the requirements for enhanced cooling increase, larger and larger AC compressors are required to meet the cooling demands for these batteries during vehicle operation and during fast charging, thereby exacerbating the NVH issues. The larger the scroll type AC compressor the greater the NVH levels. The peak cooling requirements are typically only required during fast charging making the large scroll compressor a liability during normal vehicle operation. Thus, it is desirable to provide increased battery and cabin air conditioning capabilities while reducing the NVH levels. Other desirable features and characteristics of the present disclosure will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background discussion. Documents cited during prosecution include EP 1 329 344 A1. BRIEF SUMMARY The invention is defined in the appended claims. The scope of the invention is defined in claims 1 and 10. Preferred further features are defined in the dependent claims. Disclosed herein is an electric vehicle thermal management system including a user interface for receiving a HVAC setting, a centrifugal compressor for compressing a low pressure refrigerant in a refrigerant loop to generate a high pressure refrigerant, an expansion valve for reducing a pressure of the high pressure refrigerant in the refrigerant loop to generate the low pressure refrigerant, a heat exchanger coupled to the refrigerant loop, a battery coolant loop and a cabin coolant loop, and a processor for detecting a battery cooling condition, routing one of the low pressure refrigerant and the high pressure refrigerant to the heat exchanger in response to the battery cooling condition, regulating the transfer of heat between the refrigerant loop and the battery cooling loop in response to a temperature of the battery coolant within the battery cooling loop and the battery cooling condition, and regulating the transfer of heat between the battery coolant loop and a cabin coolant loop in response to the HVAC setting and a cabin coolant temperature within the cabin coolant loop. Also disclosed herein is a method including compressing a low pressure refrigerant with a centrifugal compressor to generate a high pressure refrigerant, determining a battery cooling condition, routing one of the low pressure refrigerant and the high pressure refrigerant to the heat exchanger in response to the battery cooling condition, regulating a transfer of heat between the refrigerant loop and the battery cooling loop in response to a temperature of the battery coolant within the battery cooling loop and the battery cooling condition, and regulating the transfer of heat between the battery coolant loop and a cabin coolant loop in response to the HVAC setting and a cabin coolant temperature within the cabin coolant loop. Moreover, disclosed herein is a heat exchanger configured to exchange heat between a refrigerant loop, a battery coolant loop and a cabin coolant loop, a c