The present disclosure relates to the technical field of heat pumps, in particular to an air source CO.sub.2 heat pump system for preventing an evaporator from frosting by using heat of a heat regenerator. The air source CO.sub.2 heat pump system mainly includes an air source heat pump system, a regenerative heat exchange tank and a cooling pump. Through the regenerative heat exchange tank, on the one hand, the temperature drop of regenerative heat of the system is further increased and throttling loss is reduced; on the other hand, the heat generated by the regenerative temperature drop is configured for heat storage used for defrosting, and configured for overheating temperature rise.

A projector includes first and second cooling targets and a cooling device. The cooling device includes a first compressor, a condenser, a first expander, a first evaporator configured to change the working fluid into a working fluid in a gas phase by using heat of the first cooling target, a heat exchanger including a first flow path through which the working fluid from the first expander flows and a second flow path, a second expander configured to decompress the working fluid from the first flow path, a second evaporator configured to change the working fluid flowing into the second flow path into the working fluid in a gas phase by using heat of the second cooling target, and a second compressor. The heat exchanger cools the working fluid flowing through the first flow path by the working fluid flowing through the second flow path.

Provided are a superhigh temperature heat pump system and method capable of preparing boiling water not lower than 100° C., belonging to the technical field of heat pumps. The system comprises a compressor (1), primary and secondary evaporators (5, 6), an expansion mechanism (4), primary and secondary condenser/coolers (2, 3), water pumps (7, 8, 13), water tanks (9, 10), and a valve (14). The solution is based on the compressor exhaust heat enthalpy utilization minimum entropy gain principles/technology, and utilizes exhaust heat enthalpy sensible heat and latent heat in stages. The present invention has an output water temperature higher than 100° C., expands the functions of current heat pump water heaters which can only prepare hot water lower than 100° C., and can replace electric water heaters, save energy and increase energy utilization rates.

A heat transfer system for controlling two or more heat loads, including a high transient heat load, is provided. The heat transfer system may include sensible-heat thermal energy storage. A method of transferring heat from two or more heat loads to an ambient environment is further provided.

A system and method for reducing the refrigerant charge in a refrigeration system by preheating the liquid refrigerant before it is introduced to the evaporator inlet. When refrigerant liquid is introduced to the evaporator inlet, a portion of the refrigerant liquid vaporizes. This refrigerant vapor displaces refrigerant liquid at the inlet of the evaporator. As more refrigerant vapor is introduced, the amount of liquid inside the evaporator is reduced. A heat exchanger is placed before the liquid refrigerant inlet of the evaporator to generate more vapor when the refrigerant enters the evaporator.

The disclosed subject matter includes an active control alternating-direct flow hybrid mechanical cryogenic system, and relates to the field of cryogenic refrigeration technologies. The active control alternating-direct flow hybrid mechanical cryogenic system includes a main compressor, a Stirling cold finger, an intermediate heat exchanger, a pulse tube cold finger, a first dividing wall type heat exchanger, a final precooled heat exchanger, a second dividing wall type heat exchanger, and an evaporator that are communicated successively, where the second dividing wall type heat exchanger is connected to the evaporator through a second connecting pipeline, and a throttling element is disposed on the second connecting pipeline; a pulse tube cold head of the pulse tube cold finger is communicated with the final precooled heat exchanger through a cold chain; and a check valve is disposed on the intermediate heat exchanger.

Disclosed is a cold energy recovery-type variable-capacity air-source heat pump system, relating to combined heating and refrigerating systems running in an alternating or synchronous manner, wherein a first subsystem and a second subsystem share a double-channel variable-capacity heat exchanger; a heat exchanger main body includes two manually independent refrigerant pipe pass channels, and a refrigerant in the two channels synchronously carries out heat exchange with hot medium water in a shell pass channel; the shell pass channel establishes a water-medium heat-supplying circulation via a hot water circulation pipeline and a hot water circulation pump; the first subsystem and the second subsystem are connected to the two refrigerant pipe pass channels via a control valve group.

The refrigerant device includes a refrigerant circuit, an injection circuit, an inlet temperature sensor, an outlet temperature sensor, and a controller configured to control the operation of the refrigerant circuit. The controller includes an evaluation value calculation unit and a refrigerant amount detection unit. The evaluation value calculation unit calculates an evaluation value indicating a capability of a subcooling heat exchanger in accordance with an inlet temperature detected by the inlet temperature sensor and an outlet temperature detected by the outlet temperature sensor. The refrigerant amount detection unit determines whether there is a shortage of refrigerant in accordance with the evaluation value calculated by the evaluation value calculation unit.

A control system includes processing and memory circuitry, the memory circuitry storing a temperature-based capacity control scheme for a chiller system and the processing circuitry being configured to perform the temperature-based capacity control scheme. The motor temperature-based capacity control scheme is performed as a function of a monitored temperature in a motor configured to drive a compressor of the chiller system, a first temperature threshold corresponding to the monitored temperature, and a second temperature threshold corresponding to the monitored temperature higher than the first temperature threshold.

A projector includes first and second cooling targets and a cooling device. The cooling device includes a first compressor, a condenser, a first expander, a first evaporator configured to change the working fluid into a working fluid in a gas phase by using heat of the first cooling target, a heat exchanger including a first flow path through which the working fluid from the first expander flows and a second flow path, a second expander configured to decompress the working fluid from the first flow path, a second evaporator configured to change the working fluid flowing into the second flow path into the working fluid in a gas phase by using heat of the second cooling target, and a second compressor. The heat exchanger cools the working fluid flowing through the first flow path by the working fluid flowing through the second flow path.