Vehicle HVAC system

1. A vehicle heating, ventilation, and air conditioning (HVAC) system, comprising:

a compressor;

an interior condenser positioned on a downstream side of the compressor;

a water-cooled heat exchanger positioned on a downstream side of the interior condenser, the water-cooled heat exchanger being configured to transfer heat between a refrigerant and a coolant circulating in a coolant system;

an exterior heat exchanger positioned on a downstream side of the water-cooled heat exchanger, the exterior heat exchanger being configured to transfer heat between the refrigerant and ambient air;

a refrigerant heat exchanger configured to transfer heat between the refrigerant discharged from the water-cooled heat exchanger and the refrigerant discharged from the interior condenser; and

a first control valve located between the water-cooled heat exchanger and the interior condenser, the first control valve being configured to allow the refrigerant discharged from the interior condenser to be directed to at least one of the water-cooled heat exchanger, the refrigerant heat exchanger, and the exterior heat exchanger.

2. The vehicle HVAC system according to claim 1 , wherein the refrigerant heat exchanger includes:

a first passage through which the refrigerant discharged from the water-cooled heat exchanger passes; and

a second passage through which the refrigerant discharged from at least one of the interior condenser and the exterior heat exchanger passes.

3. The vehicle HVAC system according to claim 2 , further comprising a first bypass line configured to allow at least a portion of the refrigerant discharged from the interior condenser to be directed from an upstream point of the water-cooled heat exchanger to a downstream point of the exterior heat exchanger, wherein the first bypass line is fluidly connected to the second passage of the refrigerant heat exchanger.

4. The vehicle HVAC system according to claim 3 , further comprising a second bypass line configured to allow at least a portion of the refrigerant discharged from the interior condenser to be directed from the upstream point of the water-cooled heat exchanger to an upstream point of the exterior heat exchanger, wherein the second bypass line is fluidly connected to an inlet of the exterior heat exchanger.

5. The vehicle HVAC system according to claim 4 , wherein the first control valve includes:

an inlet port communicating with the interior condenser;

a first outlet port communicating with the water-cooled heat exchanger;

a second outlet port communicating with the first bypass line; and

a third outlet port communicating with the second bypass line.

6. The vehicle HVAC system according to claim 5 , wherein the opening degree of the first outlet port is adjusted based on a discharge pressure and a discharge temperature of the compressor.

7. The vehicle HVAC system according to claim 2 , further comprising a third bypass line configured to allow at least a portion of the refrigerant discharged from the water-cooled heat exchanger to be directed from an upstream point of the exterior heat exchanger to an upstream point of the compressor, wherein the third bypass line is fluidly connected to an inlet of the first passage of the refrigerant heat exchanger.

8. The vehicle HVAC system according to claim 7 , further comprising a second control valve configured to allow the refrigerant discharged from the water-cooled heat exchanger to be directed to at least one of the exterior heat exchanger and the first passage of the refrigerant heat exchanger.

9. The vehicle HVAC system according to claim 8 , wherein the second control valve includes:

an inlet port communicating with the water-cooled heat exchanger;

a first outlet port communicating with the exterior heat exchanger; and

a second outlet port communicating with the third bypass line.

10. The vehicle HVAC system according to claim 2 , further comprising a check valve positioned between the exterior heat exchanger and the second passage of the refrigerant heat exchanger, wherein the check valve is configured to allow the refrigerant to flow from the exterior heat exchanger to the second passage of the refrigerant heat exchanger, and to prevent the refrigerant from flowing backward from the second passage of the refrigerant heat exchanger to the exterior heat exchanger.

11. The vehicle HVAC system according to claim 2 , further comprising:

a cooling-side expansion valve positioned on a downstream side of the second passage of the refrigerant heat exchanger;

an evaporator positioned on a downstream side of the cooling-side expansion valve;

a distribution line configured to allow at least a portion of the refrigerant discharged from the second passage of the refrigerant heat exchanger to be directed from an upstream point of the cooling-side expansion valve to a downstream point of the evaporator; and

a battery chiller fluidly connected to the distribution line, and thermally connected to a battery cooling system.

12. The vehicle HVAC system according to claim 11 , further comprising a third control valve configured to allow the refrigerant discharged from the second passage of the refrigerant heat exchanger to be directed to at least one of the cooling-side expansion valve and the battery chiller.

13. The vehicle HVAC system according to claim 12 , wherein the third control valve includes:

an inlet port communicating with the second passage of the refrigerant heat exchanger;

a first outlet port communicating with the cooling-side expansion valve; and

a second outlet port communicating with the distribution line.

14. The vehicle HVAC system according to claim 13 , wherein the opening degree of the first outlet port is adjusted based on a discharge pressure of the compressor.

15. The vehicle HVAC system according to claim 13 , wherein the opening degree of the second outlet port is adjusted based on a suction pressure of the compressor.