An apparatus includes a flash tank that stores a refrigerant, a first load that uses the refrigerant to cool a first space, second and third loads, first and second compressors, and a high side heat exchanger configured to remove heat from the refrigerant. During a first mode of operation: the second load uses the refrigerant to cool a second space, the third load uses the refrigerant to cool a third space, the second compressor compresses the refrigerant from the second and third loads, and the first compressor compresses the refrigerant from the first load and the second compressor. During a second mode of operation, the second compressor compresses the refrigerant from the second load and directs the compressed refrigerant to the third load to defrost the third load.

An apparatus includes a flash tank that stores a refrigerant, a first load that uses the refrigerant to cool a first space, second and third loads, first and second compressors, and a high side heat exchanger configured to remove heat from the refrigerant. During a first mode of operation: the second load uses the refrigerant to cool a second space, the third load uses the refrigerant to cool a third space, the second compressor compresses the refrigerant from the second and third loads, and the first compressor compresses the refrigerant from the first load and the second compressor. During a second mode of operation, the second compressor compresses the refrigerant from the second load and directs the compressed refrigerant to the third load to defrost the third load.

A refrigeration system includes a dedicated defrost-mode compressor that delivers high pressure, high temperature refrigerant to one or more evaporators to defrost the evaporators.

A refrigeration system includes an expansion valve downstream of one or more medium temperature compressors. The expansion valve is configured to decrease pressure of a portion of refrigerant output by the one or more medium temperature compressors. When defrost operation of an evaporator is indicated, the refrigerant with decreased pressure from the expansion valve is provided to the evaporator for at least a period of time sufficient to defrost the evaporator.

A refrigeration assembly includes a receiver tank, a heat exchanger, a first piping assembly, and a second piping assembly. The receiver tank has a fluid outlet and a fluid inlet that receives a working fluid. The heat exchanger is disposed within the receiver tank. The heat exchanger has coiled tubing that is fluidly coupled to the fluid inlet and to the fluid outlet. The first piping assembly is disposed between and is fluidly coupled to the fluid inlet and the coiled tubing. The first piping assembly has a first double riser and a first P-trap. The second piping assembly is disposed between and is fluidly coupled to the fluid outlet and the coiled tubing. The second piping assembly includes a second double riser and a second P-trap.

The disclosed technology includes devices, systems, and methods for heat pump systems configured to operate in low ambient temperatures. The disclosed technology can include a heat pump water heater system having an evaporator, a first compressor configured to compress refrigerant to a first pressure, and a second compressor configured to compress the refrigerant to a second pressure. The second pressure can be greater than the first pressure. The heat pump water heater system can include a preheater configured to receive the refrigerant at the first pressure and heat water and a condenser configured to receive the refrigerant at the second pressure and heat water. The water can be passed through the preheater before being passed through the condenser.

The disclosed technology includes systems and methods for a heat pump water heater. The disclosed technology can include a heat pump water heater system having an evaporator, a condenser, a vapor injection line, a compressor, and a multi-fluid heat exchanger. The vapor injection line can include an expansion valve to transition refrigerant received from the condenser at a first pressure to a second pressure. The compressor can be configured to circulate refrigerant through the condenser, the multi-fluid heat exchanger, the vapor injection line, and the evaporator. The multi-fluid heat exchanger can be configured to receive refrigerant at a first pressure from the condenser, refrigerant at a second pressure from the vapor injection line, and water. The multi-fluid heat exchanger can further facilitate heat transfer between the refrigerants at the first and second pressures and the water to preheat the water before the water is passed through the condenser.

The following invention relates to a dual loop conventional chiller plant, hereafter referred to as the enhanced air conditioning chiller. Where the first loop, primary circuit, typifies refrigeration compression closed loop containing the air conditioning companion stabilizer (“aka” stabilizer); establishing efficiency enhancements. The refrigeration loop is configured to provide refrigerant at a set point temperature amenable to the charging, ice production or freezing brine solution, contained within the ice storage tank static reservoir. The enhanced air conditioning chiller air handler(s) provides space/zones climate control via a fluid at a prescribed temperature, hereafter referred to as a hydronic solution, maintaining the air temperature to the space/zones.

Methods, systems, and device for cycle enhancement are provided in accordance with various embodiments. Various embodiments generally pertain to refrigeration and heat pumping. Different embodiments may be applied to a variety of heat pump architectures. Some embodiments may integrate with vapor compression heat pumps in industrial, commercial, and/or residential applications. Some embodiments include a method that may include at least: removing a first heat from a vapor compression cycle; utilizing the first removed heat from the vapor compression cycle to drive a thermally driven heat pump; or removing a second heat from the vapor compression cycle utilizing the thermally driven heat pump to reduce a temperature of a refrigerant of the vapor compression cycle below an ambient temperature.

Methods, systems, and device for cycle enhancement are provided in accordance with various embodiments. Various embodiments generally pertain to refrigeration and heat pumping. Different embodiments may be applied to a variety of heat pump architectures. Some embodiments may integrate with vapor compression heat pumps in industrial, commercial, and/or residential applications. Some embodiments include a method that may include at least: removing a first heat from a vapor compression cycle; utilizing the first removed heat from the vapor compression cycle to drive a thermally driven heat pump; or removing a second heat from the vapor compression cycle utilizing the thermally driven heat pump to reduce a temperature of a refrigerant of the vapor compression cycle below an ambient temperature.