Vehicle heat pump system

A vehicle including a heat pump system comprising:

• a vehicle structure and a passenger compartment within the vehicle structure;
• a compressor coupled to the vehicle structure, the compressor including an inlet side and an outlet side;
• a first valve fluidly coupled to the outlet side of the compressor to receive compressed refrigerant exiting the outlet side of the compressor;
• a cooling circuit being fluidly coupled between the first valve and the inlet side of the compressor to cool the passenger compartment of the vehicle;
• a heating circuit fluidly coupled between the first valve and the inlet side of the compressor to heat the passenger compartment of the vehicle, the heating circuit including a heating circuit evaporator positioned to absorb heat from airflow exhausting the passenger compartment, the heating circuit further including a second valve located between the heating circuit evaporator and the inlet side of the compressor;
• and
• a controller operatively coupled to the first and second valves, the controller controlling the first and second valves by:
• operating the first valve to block refrigerant flow to the heating circuit and direct refrigerant flow to the cooling circuit to establish a cooling mode,
• operating the first valve to block refrigerant flow to the cooling circuit and direct refrigerant flow to the heating circuit to establish a heating mode,
• cycling the second valve between an open state where refrigerant flows from the heating circuit to the inlet of the compressor and a closed state where the second valve blocks refrigerant flow from the heating circuit to the inlet side of the compressor while the first valve is operated to establish the heating mode, such that with the second valve in the closed state the compressor draws refrigerant out of the cooling circuit and refrigerant pressure builds up within the heating circuit, and
• maintaining the second valve in the open state upon the controller determining that sufficient refrigerant has been drawn out of the cooling circuit during the cycling of the second valve.

A vehicle including a heat pump system comprising:

• a vehicle structure and a passenger compartment within the vehicle structure;
• a compressor coupled to the vehicle structure, the compressor including an inlet side and an outlet side;
• a first valve fluidly coupled to the outlet side of the compressor to receive compressed refrigerant exiting the outlet side of the compressor, the first valve being movable between a first setting establishing a cooling mode and a second setting establishing a heating mode;
• a cooling circuit being fluidly coupled between the first valve and the inlet side of the compressor to cool the passenger compartment of the vehicle in the cooling mode, the cooling circuit including a cooling circuit evaporator located within the passenger compartment;
• a heating circuit fluidly coupled between the first valve and the inlet side of the compressor to heat the passenger compartment of the vehicle in the heating mode, the heating circuit including a heating circuit evaporator positioned to absorb heat from airflow exhausting the passenger compartment, the heating circuit being fluidly coupled to the cooling circuit evaporator such that, the cooling circuit evaporator operates as a heating circuit condenser in the heating circuit in the heating mode, and
• a controller operatively coupled to the first valves to control the first valve.