Cooling system of battery

1. A cooling system of a battery in a vehicle which mounts said battery which supplies electric power for driving the vehicle, an air-conditioning system which is provided with an electric compressor, an outside heat exchanger, and an inside heat exchanger which are connected by a refrigerant path through which a first refrigerant flows, and a control unit, said system comprising:

a branch path which connects a downstream side of said outside heat exchanger and an upstream side of said electric compressor in said refrigerant path,

a battery heat exchanger which is provided in said branch path,

a medium path which is connected to said battery heat exchanger and through which a second refrigerant which cools said battery runs, and

a cooling control device which adjusts the flow rates of said first refrigerant which flows through said refrigerant path and said branch path, wherein

when said cooling control device directs said first refrigerant to both said refrigerant path and said branch path, it makes said control unit increase a target speed of said electric compressor,

when control of said air-conditioning system by said control unit is given priority, said cooling control device adjusts said flow regulators to run the entire amount of said first refrigerant to said refrigerant path, while

when cooling of said battery by said cooling control device is given priority over control of said air-conditioning system by said control unit, said cooling control device adjusts said flow regulators to make an amount of said first refrigerant which flows to said branch path increase and runs the entire amount of said first refrigerant to said branch path when the cooling priority of said battery is higher than a predetermined level

when said cooling control device controls said flow regulators to run said first refrigerant to said branch path and, furthermore, makes a target speed of said electric compressor increase, said cooling control device first increases the target speed of said electric compressor, then, after a predetermined time elapses, controls said flow regulators to run said first refrigerant to said branch path; and

said cooling control device increases the flow rate of said second refrigerant after running said first refrigerant to said branch path.

2. The cooling system of a battery as set forth in claim 1 , wherein

said cooling control device is provided with flow regulators which regulate the flow rates of said first refrigerant which flows through said refrigerant path and said branch path;

when control of said air-conditioning system by said control unit is given priority, said cooling control device adjusts said flow regulators to run the entire amount of said first refrigerant to said refrigerant path, while

when cooling of said battery by said cooling control device is given priority over control of said air-conditioning system by said control unit, said cooling control device adjusts said flow regulators to make an amount of said first refrigerant which flows to said branch path increase and runs the entire amount of said first refrigerant to said branch path when the cooling priority of said battery is higher than a predetermined level.

3. The cooling system of a battery as set forth in claim 2 , wherein said cooling control device determines the cooling priority of said battery in accordance with a temperature of said second refrigerant or a temperature of said battery and makes a target speed of said electric compressor increase when cooling of the battery is given priority by the control unit.

4. The cooling system of a battery as set forth in claim 1 , wherein said cooling control device makes a target speed of said electric compressor increase if an outside air temperature becomes higher than a predetermined temperature.

5. The cooling system of a battery as set forth in claim 3 , wherein said cooling control device makes a target speed of said electric compressor increase if an outside air temperature becomes higher than a predetermined temperature.

6. The cooling system of a battery as set forth in claim 1 , wherein said cooling control device makes a target speed of said electric compressor increase in accordance with a vehicle speed if the vehicle speed becomes higher than a predetermined speed.

7. The cooling system of a battery as set forth in claim 4 , wherein said cooling control device makes a target speed of said electric compressor increase in accordance with a vehicle speed if the vehicle speed becomes higher than a predetermined speed.

8. The cooling system of a battery as set forth in claim 1 , wherein said cooling control device determines an increase of a target speed of said electric compressor increase in accordance with a combination of a temperature of said second refrigerant, a temperature of said battery, an outside air temperature, a the vehicle speed.

9. The cooling system of a battery as set forth in claim 2 , wherein said cooling control device determines an increase of a target speed of said electric compressor in accordance with a combination of a temperature of said second refrigerant, a temperature of said battery, an outside air temperature, and a vehicle speed.

10. The cooling system of a battery as set forth in claim 8 , wherein when said cooling control device controls said flow regulators to run said first refrigerant to said branch path and, furthermore, makes the target speed of said electric compressor increase, said cooling control device first increases the target speed of said electric compressor, then, after a predetermined time elapses, controls said flow regulators to run said first refrigerant to said branch path.

11. The cooling system of a battery as set forth in claim 1 , wherein said vehicle is either an electric vehicle or a hybrid vehicle.