Direct-current frequency-conversion carbon dioxide heat pump chilling and heating unit

Abstract

The invention discloses a direct-current frequency-conversion carbon dioxide heat pump chilling and heating unit. The direct-current frequency-conversion carbon dioxide heat pump chilling and heatingunit comprises a compressor, an air cooler, a first expansion valve, a second expansion valve, an evaporator, a four-way valve and an air-supplying enthalpy-adding heat exchanger, wherein a first heat-exchange pipe and a heat-exchange water way are arranged in the air cooler, and heat can be exchanged between the first heat-exchange pipe and the heat-exchange water way; a second heat-exchange pipeand a third heat-exchange pipe are arranged in the air-supplying enthalpy-adding heat exchanger, and heat can be exchanged between the second heat-exchange pipe and the third heat-exchange pipe; thecompressor is a direct-current frequency-conversion compressor. Switching between a heating mode and a refrigeration mode of the heat pump unit is achieved by controlling valve ports of the four-way valve to be opened and closed; in the heating mode, the compressor, the first valve port, the fourth valve port, the first heat-exchange pipe, the second heat-exchange pipe, the first expansion valve,the evaporator, the third valve port and the second valve port are communicated in sequence through a refrigeration agent pipeline; in the refrigeration mode, the compressor, the first valve port, thethird valve pot, the evaporator, the first expansion valve, the second heat-exchange pipe, the first heat-exchange pipe, the fourth valve port and the second valve port are communicated in sequence through the refrigeration agent pipeline.

Description

technical field [0001] The invention belongs to the technical field of carbon dioxide heat pumps, and in particular relates to a direct-current variable frequency carbon dioxide heat pump cooling and heating unit. Background technique [0002] The carbon dioxide heat pump unit uses carbon dioxide as a refrigerant. The heat release of carbon dioxide is a supercritical cycle. Using the thermophysical properties of carbon dioxide, the compressor has a high exhaust temperature and relatively high energy efficiency. It is widely used in various heating systems and hot water projects. A carbon dioxide heat pump unit usually includes a compressor, an air cooler, an expansion valve, and an evaporator connected in sequence through a refrigerant pipeline. On the side of the air cooler, the refrigerant pipeline can exchange heat with the water circuit at the user end to supply heat to the user Water, the single-stage carbon dioxide heat pump unit can work normally at around -25°C, and ...

AI Technical Summary

Problems solved by technology

However, the existing carbon dioxide heat pumps generally do not have cooling and heating units, that is, they cannot achieve both heating and cooling like air conditioners, and their application range is relatively single.

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