Heat pump system with multi-way-position valve

A vehicle heat pump system comprising:

• a thermal loop including a compressor and an expansion device to reduce a pressure of refrigerant flow, and an internal heat exchanger upstream of the expansion device;
• a first portion of a thermal loop including an outside heat exchanger;
• a second portion of the thermal loop including a cabin heat exchanger and a flash tank upstream of the cabin heat exchanger and downstream of the expansion device to separate vapor-liquid mixture;
• an eight-way valve downstream of the compressor and having a first position in which refrigerant flows within the portions in a cooling mode and a second position in which refrigerant flows within the portions in a heating mode;
• and
• a controller to switch the eight-way valve between the first and second positions,
• wherein the outside heat exchanger operates as a condenser in the cooling mode and the eight-way valve directs refrigerant flow from the outside heat exchanger to the cabin heat exchanger, wherein the outside heat exchanger operates as an evaporator in the heating mode and the eight-way valve directs refrigerant flow from the cabin heat exchanger to the outside heat exchanger, and wherein the flash tank is arranged with the eight-way valve to substantially remove vapor from the refrigerant such that the refrigerant is substantially entirely liquid when entering the cabin heat exchanger in the cooling mode or entering the outside heat exchanger in the heating mode, and the flash tank balances a pressure of the refrigerant flowing from the flash tank and the eight-way valve via a control valve downstream of the flash tank.