Cascade heat pump air-conditioning unit

Abstract

The invention discloses a cascade heat pump air-conditioning unit comprising a surface cooling type heat exchanger whose shell side inlet and outlet are sequentially in serial connection and the first level and second level cryogen-air heat exchanger. The shell side outlet of a second level cryogen-air heat exchanger is connected with the fan inlet. A compressor, a cryogen-water heat exchanger and a capillary pipe are connected between the outlet and the inlet of the tube side of the first level and second level cryogen-air heat exchanger. One end of a water supply pipe connected with the water source and installed with a first stop valve is communicated with the tube side inlet of the surface cooling type heat exchanger and the water supply pipe is communicated with a water supply branch tube provided with a second stop valve. The other end of the water supply branch tube is connected with the tube side inlet of the cryogen-water heat exchanger. The tube side outlet of the surface cooling type heat exchanger is communicated with the water supply branch tube through a water supply return pipe. The tube side outlet of the cryogen-water heat exchanger is communicated with a water output pipe. The invention can perform cascade refrigeration and heating circulation and balance underground temperature field.

Description

technical field [0001] The invention relates to refrigeration air-conditioning and heat pump technology, in particular to cascade heat pump air-conditioning units. Background technique [0002] At present, the heat pump system has been recognized by more and more people for its advantages of energy saving, environmental protection and good operation effect. Although the heat pump technology is becoming more and more mature, the existing problems cannot be ignored. For example, how to further improve the economy of the system and save operating costs for the household-type ground source heat pump system that is being promoted and applied, so that the heat pump system can become an air-conditioning system that ordinary residents can choose; Most areas have different loads in winter and summer, and the resulting changes in the underground temperature field will not only affect the operating efficiency of the system, but also affect the local ecological environment; R22 is still...

AI Technical Summary

Problems solved by technology

Although the heat pump technology is becoming more and more mature, the existing problems cannot be ignored. For example, how to further improve the economy of the system, save operating costs, and make the heat pump system an air-conditioning system that ordinary residents can choose; Most areas have different loads in winter and summer, and the resulting changes in the underground temperature field will not only affect the operating efficiency of the system, but also affect the local ecological environment; R22 is still the main refrigerant in the current air-conditioning and heating systems. In the global environment, the use of HCFCs refrigerants is being gradually restricted, and

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