Transcritical CO2 compound heat pump and control method thereof

Abstract

The invention discloses a transcritical CO2 compound heat pump and a control method thereof. The transcritical CO2 compound heat pump comprises a CO2 main path compressor, an air cooling-air cooling recombiner, a supercooling-evaporation recombiner, an evaporator and a CO2 auxiliary compressor, wherein the air cooling-air cooling recombiner comprises a CO2 main path, a CO2 auxiliary path and a water path; and the supercooling-evaporation recombiner comprises a CO2 main path supercooling section and a CO2 auxiliary evaporation section. According to the invention, the transcritical CO2 compound heat pump comprises two working modes according to the return water temperature, the application range of a unit is wider, and daily requirements are met; the transcritical CO2 compound heat pump only has one refrigerant and water heat exchanger, and compared with a conventional transcritical CO2 compound heat pump with three water and refrigerant heat exchangers, the transcritical CO2 compound heat pump has the advantages that a circulating water path is a single loop with one inlet and one outlet, the system is simple, and the failure rate is decreased; and an auxiliary loop adopts an inverter compressor, a heat pump water heater system can stably and reliably operate for a long time under the conditions of wider load and temperature, the power consumption is reduced, and the starting current of the compressor can be decreased.

Description

technical field [0001] The invention belongs to the technical field of heat pumps, in particular to a transcritical CO 2 Compound heat pump and its control method. Background technique [0002] The heat pump can absorb the heat in the ambient air, transfer the heat to the circulating water through the circulation of the working medium, and play the role of heating. Traditional heat pumps mostly use traditional working fluids such as R134a and R410a, which are poor in environmental protection and are facing a trend of being phased out. [0003] G Lorentzen, former president of the International Institute of Refrigeration, proposed the CO 2 The transcritical cycle theory points out that it will have extremely broad development prospects in the field of heat pumps. CO 2 The critical temperature is very low at 31.1°C, so CO 2 Heat pump systems generally use a transcritical cycle. CO 2 The exhaust temperature of the transcritical cycle compressor is relatively high (up to ...

AI Technical Summary

Problems solved by technology

[0009] The object of the present invention is to provide a kind of transcritical CO 2 Compound heat pump and its control method to solve existing transcritical CO 2 The performance of the composite heat pump is severely restricted by the outlet temperature of the gas cooler, the complexity of water distribution and connection, and the waste of energy

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