Vehicle thermal management system, heat transfer medium and method for cooling vehicle driving battery

Abstract

A vehicle thermal management system includes a vehicle driving battery that generates heat during charging and discharging and a liquid heat transfer medium that transfers the heat received from the battery. The system further includes a heat receiver that causes the heat transfer medium to receive the heat and a refrigerant heat exchanger that causes the heat transfer medium to release the heat. The heat transfer medium includes a liquid base material including water and an orthosilicic acid ester compatible with the liquid base material and does not include an ionic rust inhibitor. The orthosilicic acid ester is present, as a concentration of silicon, relative to a total mass of the heat transfer medium within a range between 1 mass ppm, inclusive, and 2000 mass ppm, inclusive or within a range between 2000 mass ppm, non-inclusive, and 10000 mass ppm, inclusive.

1 . A vehicle thermal management system mounted in a vehicle, the system comprising:
 a vehicle driving battery that is configured to be charged with electric power supplied from an external power source and generates heat during charging and discharging;   a liquid heat transfer medium that transfers the heat received from the battery;   a heat receiver that is configured to cause the heat transfer medium to receive the heat through heat exchange with the battery, the heat receiver including a portion that is in contact with the heat transfer medium and is made of a material containing aluminum; and   a refrigerant heat exchanger that is configured to cause the heat transfer medium to release the heat through heat exchange with a refrigerant for a cooling cycle system, the refrigerant heat exchanger including a portion that is in contact with the heat transfer medium and is made of a material containing aluminum, wherein   the heat transfer medium includes a liquid base material including water and an orthosilicic acid ester compatible with the liquid base material and does not include an ionic rust inhibitor, and   the orthosilicic acid ester is present, as a concentration of silicon, relative to a total mass of the heat transfer medium within a range between 1 mass ppm, inclusive, and 2000 mass ppm, inclusive, or within a range between 2000 mass ppm, non-inclusive, and 10000 mass ppm, inclusive.   
     
     
         2 . The vehicle thermal management system according to  claim 1 , further comprising
 an air heat exchanger that is configured to cause the heat transfer medium to release heat through heat exchange with an air outside of the vehicle, wherein   the air heat exchanger includes a portion that is in contact with the heat transfer medium and is made of a material containing aluminum.   
     
     
         3 . The vehicle thermal management system according to  claim 1 , further comprising
 an oil heat exchanger that is configured to cause the heat transfer medium to receive heat through heat exchange with an oil for cooling a motor generator, wherein   the oil heat exchanger includes a portion that is in contact with the heat transfer medium and is made of a material containing aluminum.   
     
     
         4 . The vehicle thermal management system according to  claim 1 , further comprising
 an inverter heat exchanger that is configured to cause the heat transfer medium to receive heat through heat exchange with an inverter, wherein   the inverter heat exchanger includes a portion that is in contact with the heat transfer medium and is made of a material containing aluminum.   
     
     
         5 . The vehicle thermal management system according to  claim 1 , further comprising
 an ion exchanger that is configured to capture ions generated in the heat transfer medium.   
     
     
         6 . A vehicle thermal management system mounted in a vehicle, the system comprising:
 a vehicle driving battery that is configured to be charged with electric power supplied from an external power source and generates heat during charging and discharging;   a liquid heat transfer medium that transfers the heat received from the battery;   a heat receiver that is configured to cause the heat transfer medium to receive the heat through heat exchange with the battery, the heat receiver including a portion that is in contact with the heat transfer medium and is made of a material containing aluminum; and   a refrigerant heat exchanger that is configured to cause the heat transfer medium to release the heat through heat exchange with a refrigerant for a cooling cycle system, the refrigerant heat exchanger including a portion that is in contact with the heat transfer medium and is made of a material containing aluminum, wherein   the heat transfer medium includes a liquid base material including water, an orthosilicic acid ester compatible with the liquid base material, and an azole derivative and has an electric insulation property.   
     
     
         7 . The vehicle thermal management system according to  claim 6 , wherein
 the heat transfer medium has an electrical conductivity of 50 μS/cm or less.   
     
     
         8 . A heat transfer medium for a vehicle thermal management system that includes:
 a vehicle driving battery that is configured to be charged with electric power supplied from an external power source and generates heat during charging and discharging;   a heat receiver that is configured to cause the heat transfer medium to receive the heat through heat exchange with the battery, the heat receiver including a portion that is in contact with the heat transfer medium and is made of a material containing aluminum; and   a refrigerant heat exchanger that is configured to cause the heat transfer medium to release the heat through heat exchange with a refrigerant for a cooling cycle system, the refrigerant heat exchanger including a portion that is in contact with the heat transfer medium and is made of a material containing aluminum, the heat transfer medium comprising:   a liquid base material including water;   an orthosilicic acid ester compatible with the liquid base material; and   an azole derivative, wherein   the heat transfer medium has an electric insulation property.   
     
     
         9 . The heat transfer medium according to  claim 8 , wherein
 the heat transfer medium has an electrical conductivity of 50 μS/cm or less.   
     
     
         10 . A heat transfer medium for a vehicle thermal management system that includes:
 a vehicle driving battery that is configured to be charged with electric power supplied from an external power source and generates heat during charging and discharging;   a heat receiver that is configured to cause the heat transfer medium to receive the heat through heat exchange with the battery, the heat receiver including a portion that is in contact with the heat transfer medium and is made of a material containing aluminum; and   a refrigerant heat exchanger that is configured to cause the heat transfer medium to release the heat through heat exchange with a refrigerant for a cooling cycle system, the refrigerant heat exchanger including a portion that is in contact with the heat transfer medium and is made of a material containing aluminum, the heat transfer medium comprising   a liquid base material including water; and   an orthosilicic acid ester compatible with the liquid base material, wherein   the heat transfer medium does not include an ionic rust inhibitor, and   the orthosilicic acid ester is present, as a concentration of silicon, relative to a total mass of the heat transfer medium within a range between 1 mass ppm, inclusive, and 2000 mass ppm, inclusive or within a range between 2000 mass ppm, non-inclusive, and 10000 mass ppm, inclusive.   
     
     
         11 . A method for cooling a vehicle driving battery that generates heat during charging and discharging, the method comprising:
 circulating a heat transfer medium through a heat transfer medium circuit, the heat transfer medium comprising:
 a liquid base material including water; 
 an orthosilicic acid ester compatible with the liquid base material; and 
 an azole derivative, wherein 
 the heat transfer medium has an electric insulation property; 
   causing, at a heat receiver including a portion that is in contact with the heat transfer medium and is made of a material containing aluminum, the heat transfer medium to receive the heat through heat exchange between the heat transfer medium and the battery that is configured to be charged with electric power supplied from an external power source; and   causing, at a refrigerant heat exchanger including a portion that is in contact with the heat transfer medium and is made of a material containing aluminum, the heat transfer medium to release the heat through heat exchange between a refrigerant for a cooling cycle circuit and the heat transfer medium having received the heat.   
     
     
         12 . A method for cooling a vehicle driving battery that generates heat during charging and discharging, the method comprising:
 circulating a heat transfer medium through a heat transfer medium circuit, the heat transfer medium comprising:
 a liquid base material including water; and 
 an orthosilicic acid ester compatible with the liquid base material, the orthosilicic acid ester being present, as a concentration of silicon, relative to a total mass of the heat transfer medium within a range between 1 mass ppm, inclusive, and 2000 mass ppm, inclusive or within a range between 2000 mass ppm, non-inclusive, and 10000 mass ppm, inclusive, wherein 
 the heat transfer medium does not include an ionic rust inhibitor; 
   causing, at a heat receiver including a portion that is in contact with the heat transfer medium and is made of a material containing aluminum, the heat transfer medium to receive the heat through heat exchange between the heat transfer medium and the battery that is configured to be charged with electric power supplied from an external power source; and   causing, at a refrigerant heat exchanger including a portion that is in contact with the heat transfer medium and is made of a material containing aluminum, the heat transfer medium to release the heat through heat exchange between a refrigerant for a cooling cycle circuit and the heat transfer medium having received the heat.   
     
     
         13 . The method according to  claim 11 , further comprising
 causing, at an air heat exchanger including a portion that is in contact with the heat transfer medium and is made of a material containing aluminum, the heat transfer medium to further release the heat through heat exchange between the heat transfer medium and an air outside of a vehicle.   
     
     
         14 . The method according to  claim 11 , further comprising
 causing, at an oil heat exchanger including a portion that is in contact with the heat transfer medium and is made of a material containing aluminum, the heat transfer medium to further receive the heat through heat exchange between the heat transfer medium and an oil for cooling a motor generator.   
     
     
         15 . The method according to  claim 11 , further comprising
 causing, at an inverter heat exchanger including a portion that is in contact with the heat transfer medium and is made of a material containing aluminum, the heat transfer medium to further receive the heat through heat exchange between the heat transfer medium and an inverter.