Advanced refrigeration system

A transportation refrigeration system operable in a cooling mode, a defrost mode, and a heating mode to condition air in an air-conditioned space, the system comprising:

• a refrigeration circuit fluidly connecting a compressor, a condenser, a tank, and an evaporator, the evaporator being in thermal communication with the air-conditioned space;
• a heating circuit fluidly connecting the compressor, the tank, the evaporator, and a heater;
• and
• a defrost circuit fluidly connecting the compressor, the tank, the evaporator, and the heater;
• wherein a quantity of oil is mixed with the refrigerant in the compressor, the tank separating at least some of the oil from the refrigerant.

A transportation refrigeration system for conditioning air in an air-conditioned space, the refrigeration system comprising:

• a storage tank having a first opening, a second opening, and a third opening;
• a refrigeration circuit coupled to the first and second openings and being in thermal communication with the air-conditioned space;
• a heating circuit coupled to the first and third openings and being in thermal communication with the air-conditioned space;
• and
• a defrost circuit coupled to the first and third openings, wherein the tank separates oil and refrigerant from an oil/refrigerant mixture.

A method of conditioning air in an air-conditioned space with a transportation refrigeration system, the refrigeration system housing a refrigerant, the method comprising:

• directing substantially all of the refrigerant through a refrigeration circuit during operation in a cooling mode, the refrigeration circuit including a tank and an evaporator, the evaporator being in thermal communication with the air-conditioned space;
• directing substantially all of the refrigerant through a heating circuit during operation in a heating mode, the heating circuit including the tank, the evaporator coil, and a heater;
• and
• directing substantially all of the refrigerant through a defrost circuit during operation in a defrost mode, the defrost circuit extending through the tank, the heater, and the evaporator.

A method of conditioning air in an air-conditioned space with a transportation refrigeration system, the refrigeration system housing a refrigerant, the method comprising:

• directing substantially all of the refrigerant through a refrigeration circuit during operation in a cooling mode, the refrigeration circuit including a tank and an evaporator, the evaporator being in thermal communication with the air-conditioned space;
• directing substantially all of the refrigerant through a heating circuit during operation in a heating mode, the heating circuit including the tank, the evaporator coil, and a heater;
• directing substantially all of the refrigerant through a defrost circuit during operation in a defrost mode, the defrost circuit extending through the tank, the heater, and the evaporator;
• and
• mixing a quantity of oil with the refrigerant in the compressor and separating at least some of the oil from the refrigerant in the tank.

A method of conditioning air in an air-conditioned space with a transportation refrigeration system, the method comprising:

• directing a refrigerant along a refrigeration circuit through a compressor, a condenser, a tank, and an evaporator coil;
• removing substantially all of the refrigerant from the condenser;
• directing the refrigerant along a heating circuit through the compressor, the tank, a heater, and the evaporator coil;
• moving air from an air-conditioned space across the evaporator coil, transferring heat between the air and the evaporator coil, and returning the air to the air-conditioned space;
• and
• separating an oil and the refrigerant from an oil/refrigerant mixture.

A transportation refrigeration system operable in a cooling mode, a defrost mode, and a heating mode to condition air in an air-conditioned space, the system comprising:

• a refrigeration circuit fluidly connecting a compressor, a condenser, a tank, and an evaporator, the evaporator being in thermal communication with the air-conditioned space;
• a heating circuit fluidly connecting the compressor, the tank, the evaporator, and a heater;
• and
• a defrost circuit fluidly connecting the compressor, the tank, the evaporator, and the heater;
• a first flow path extending between the compressor and the condenser, the first flow path including a first valve having a first open condition allowing the flow of fluid along the first flow path and a first closed condition preventing flow of fluid along the first flow path;
• a second flow path extending between the condenser and the tank, the second flow path having a check valve operable to prevent fluid flow into the condenser;
• a third flow path extending between the compressor and the evaporator, the third flow path including a second valve having a second open condition allowing the flow of fluid along the third flow path and a second closed condition preventing flow of fluid along the third flow path;
• a fourth flow path extending between the compressor and the tank, the fourth flow path including a third valve having a third open condition allowing the flow of fluid along the fourth flow path and a third closed condition preventing flow of fluid along the fourth flow path;
• a fifth flow path extending between the condenser and the compressor, the fifth flow path including a fourth valve having a fourth open condition allowing the flow of fluid along the fifth flow path and a fourth closed condition preventing flow of fluid along the fifth flow path;
• and
• a sixth flow path extending between the evaporator and the compressor, the sixth flow path having a fifth valve operable to regulate flow between the evaporator and the compressor.