The present invention provides a system and method for an improved multistage, cascade refrigeration system using hot gas defrost to rid the evaporator of ice build-up which accumulates over time, while the air in the evaporator enclosure remains below the freezing point of water. The present invention thus provides greater defrost flexibility with increased ease of design and implementation than current refrigeration systems, which allows for more robust hot gas defrost function for multistage refrigeration systems, such that it is unaffected by temperature changes of the condensing fluid (ambient air temperature for air cooled condensers, water temperature for water cooled condensers), and can be readily adapted to any refrigerant suitable for a selected temperature range.

The present invention provides a system and method for an improved multistage, cascade refrigeration system using hot gas defrost to rid the evaporator of ice build-up which accumulates over time, while the air in the evaporator enclosure remains below the freezing point of water. The present invention thus provides greater defrost flexibility with increased ease of design and implementation than current refrigeration systems, which allows for more robust hot gas defrost function for multistage refrigeration systems, such that it is unaffected by temperature changes of the condensing fluid (ambient air temperature for air cooled condensers, water temperature for water cooled condensers), and can be readily adapted to any refrigerant suitable for a selected temperature range.

Provided is a binary refrigeration apparatus including: a low-temperature side refrigeration circuit including a spiral heat exchanger including a main tube and a spiral tube wound around the main tube in a spiral form, the main tube being a tube where a low-temperature side refrigerant that flows into a low-temperature side compressor enters, the spiral tube being a tube where the low-temperature side refrigerant flown out from the low-temperature side compressor enters; and a high-temperature side refrigeration circuit where a high-temperature side refrigerant that exchanges heat with the low-temperature side refrigerant through a plate heat exchanger circulates.

Provided is a binary refrigeration apparatus including: a low-temperature side refrigeration circuit including a spiral heat exchanger including a main tube and a spiral tube wound around the main tube in a spiral form, the main tube being a tube where a low-temperature side refrigerant that flows into a low-temperature side compressor enters, the spiral tube being a tube where the low-temperature side refrigerant flown out from the low-temperature side compressor enters; and a high-temperature side refrigeration circuit where a high-temperature side refrigerant that exchanges heat with the low-temperature side refrigerant through a plate heat exchanger circulates.

The present application provides a compound refrigeration system for a heat pipe of a supergravity centrifuge. The compound refrigeration system for the heat pipe of the supergravity centrifuge includes a rotor rotating around a vertical axis, an experimental cabin covering outside the rotor, and a corresponding cooling system. The rotor is provided with a shaft part which is in running fit with the experimental cabin. The shaft part is provided with a shaft top end located outside the experimental cabin. The cooling system includes a liquid cooling device and an evaporative cooling device. The liquid cooling device comprises a refrigeration source, and a first cooling medium circulating pipeline communicated with the refrigeration source and thermally coupled with a cabin wall of the experimental cabin. The evaporative cooling device includes a condensation chamber arranged outside the experimental cabin, and a heat pipe radiator thermally coupled with the rotor.

The present application provides a compound refrigeration system for a heat pipe of a supergravity centrifuge. The compound refrigeration system for the heat pipe of the supergravity centrifuge includes a rotor rotating around a vertical axis, an experimental cabin covering outside the rotor, and a corresponding cooling system. The rotor is provided with a shaft part which is in running fit with the experimental cabin. The shaft part is provided with a shaft top end located outside the experimental cabin. The cooling system includes a liquid cooling device and an evaporative cooling device. The liquid cooling device comprises a refrigeration source, and a first cooling medium circulating pipeline communicated with the refrigeration source and thermally coupled with a cabin wall of the experimental cabin. The evaporative cooling device includes a condensation chamber arranged outside the experimental cabin, and a heat pipe radiator thermally coupled with the rotor.

A thermal management system for a gas turbine engine includes a primary vapor compression system including a primary evaporator defining thermal communication between a primary refrigerant and a flow of fuel to cool the fuel. A boost vapor compression system includes a boost heat exchanger defining thermal communication between the primary refrigerant. A boost refrigerant cools the primary refrigerant and a boost condenser in thermal communication with an air stream cools the boost refrigerant.

In one instance, a multistage microchannel condenser is provided for use as an aspect of a heating, ventilating, and air conditioning (HVAC) system. The multistage microchannel condenser includes at least two pluralities of flat tubes having microchannels, each associated with a different refrigeration circuit, that are interspersed so that when only one refrigeration circuit is operational, the multistage microchannel condenser still does not have any substantial thermal dead spots. Manifolds are used on each end of the multistage microchannel condenser to fluidly couple members of the at least two pluralities of flat tubes such that the refrigerant in each refrigeration circuit remains separated while still using a majority of the area of the face of the multistage microchannel condenser. Other aspects are presented.

In one instance, a multistage microchannel condenser is provided for use as an aspect of a heating, ventilating, and air conditioning (HVAC) system. The multistage microchannel condenser includes at least two pluralities of flat tubes having microchannels, each associated with a different refrigeration circuit, that are interspersed so that when only one refrigeration circuit is operational, the multistage microchannel condenser still does not have any substantial thermal dead spots. Manifolds are used on each end of the multistage microchannel condenser to fluidly couple members of the at least two pluralities of flat tubes such that the refrigerant in each refrigeration circuit remains separated while still using a majority of the area of the face of the multistage microchannel condenser. Other aspects are presented.

The disclosed technology includes a heat pump having a thermal energy storage (TES) material. The heat pump can include a first heat exchanger to exchange heat between ambient air and refrigerant, a second heat exchanger to exchange heat between the refrigerant and air supplied to a climate-controlled space, and a third heat exchanger to exchange heat between the TES material and the refrigerant in a first fluid path and the refrigerant in a second fluid path. The heat pump can include a first compressor to circulate refrigerant to the first, second, and third heat exchangers and a second compressor to circulate refrigerant to the second and third heat exchangers. The first compressor can facilitate heat exchange between the ambient air and the TES material and the second compressor can facilitate heat exchange between the TES material and the air supplied to the climate-controlled space.