Heat pump refrigerant loop arrangements

A heat pump, comprising:

• a refrigerant loop, wherein the refrigerant loop comprises:
• a compressor;
• a first condenser downstream of the compressor and coupled to an outlet port of the compressor;
• a vapor generator downstream of the first condenser, wherein the vapor generator comprises a first region and a second region;
• a branching point positioned between the first condenser and the vapor generator, wherein the branching point diverts a portion of a first heat exchange fluid circulating through the refrigerant loop to the first region of the vapor generator;
• a first expansion valve positioned between the branching point and the second region of the vapor generator, wherein an outlet of the second region of the vapor generator is coupled to a mid-pressure inlet port of the compressor, wherein the vapor generator transfers heat from the first region of the vapor generator to the second region of the vapor generator such that a vapor percentage and a temperature of the first heat exchange fluid flowing through the second region of the vapor generator increases, and wherein the higher temperature, higher vapor percentage first heat exchange fluid is provided to the mid-pressure inlet port of the compressor;
• a second expansion valve positioned downstream of the vapor generator and coupled to an outlet of the second region of the vapor generator, wherein an inlet of the second region of the vapor generator is coupled to the first condenser;
• and
• a first evaporator downstream of the second expansion valve and coupled to the second expansion valve, wherein the first evaporator is upstream of the compressor and is coupled to a low-pressure inlet port of the compressor.