Vehicle refrigerant system using hot gas bypass with vapor injection

A vehicle comprising a refrigerant system, the refrigerant system comprising:

• a compressor including at least a first stage input, a second stage input, and an output arranged to provide an output vapor refrigerant;
• a condenser fluidly coupled to the output of the compressor to receive the output vapor refrigerant;
• an evaporator fluidly coupled between the condenser and the first stage input, wherein the evaporator is arranged to provide refrigerant in vapor form to the first stage input of the compressor;
• a chiller fluidly coupled between the condenser and both the first and second stage inputs, wherein the chiller is arranged to inject refrigerant in vapor form into the first stage input or the second stage input;
• an accumulator fluidly coupled between the first stage input and both the chiller and the evaporator;
• and
• a bypass branch fluidly coupling the output of the compressor to the accumulator;
• and
• an outside heat exchanger with a forward mode during a cooling operation, wherein the heat exchanger operates as a condenser in a forward mode and as an evaporator in a reverse mode;
• and wherein in the reverse mode, at least part of the bypass branch forms at least part of a fluid passage to the accumulator.

A heating and cooling system on a vehicle, comprising:

• a compressor including a first stage input, a second stage input, and an output arranged to provide an output vapor refrigerant;
• a condenser fluidly coupled to the output of the compressor to receive the output vapor refrigerant;
• an evaporator fluidly coupled between the condenser and the first stage input, wherein the evaporator is arranged to provide refrigerant in vapor form to the first stage input of the compressor;
• a chiller fluidly coupled between the condenser and the first stage input to provide a two-phase refrigerant;
• an accumulator fluidly coupled between the first stage input and the chiller to receive the two-phase refrigerant;
• a bypass branch fluidly coupling the output of the compressor to the accumulator to heat the two-phase refrigerant;
• and
• a heat exchanger having an expansion control valve and being between the condenser and the second stage input to inject vapor into the second stage input at a first pressure higher than a second pressure of vapor entering the first stage input;
• a pressure and temperature sensor coupled between the first stage input and the accumulator;
• and
• at least one processor receiving signals from the sensor and used to determine an amount of refrigerant to flow through the bypass.