Two-stage compression heat pump system capable of realizing two-time throttling and intermediate incomplete cooling

Abstract

The invention discloses a two-stage compression heat pump system capable of realizing two-time throttling and intermediate incomplete cooling, and aims to provide a system for defrosting through a heat pump with low-pressure-stage compressors during heating in winter. The two-stage compression heat pump system comprises a high-pressure-stage compressor set, an indoor heat exchanger, a first throttling valve, a first solenoid valve, a second solenoid valve, a third solenoid valve, an intermediate cooler and a plurality of low-pressure-stage units. Each low-pressure-stage unit comprises the corresponding low-pressure-stage compressor, a four-way reversing valve, a second throttling valve, an outdoor heat exchanger, a first one-way valve, a second one-way valve, a third one-way valve and a fourth one-way valve. Two-time throttling, intermediate incomplete cooling and heating / defrosting cycle in winter and single-stage compression refrigerating cycle in summer are achieved through connector switching of a first four-way reversing valve and opening and closing of a first two-way valve, a second two-way valve and a third two-way valve. Defrosting cycle and heating cycle are both two-stage compression cycle, temperature fluctuation is small, the defrosting efficiency high, the compressors can operate stably, and the service life of the system is prolonged.

Description

technical field [0001] The present invention relates to the technical field of heat pump air conditioners, and more specifically, relates to a two-stage compression heating cycle in which hot gas is used to defrost outdoor heat exchangers in turn in winter, and incomplete cooling in the middle of secondary throttling, and single-stage compression refrigeration in summer. Cyclic heat pump system. Background technique [0002] The air source heat pump is an energy-saving device based on a low-temperature heat source that uses low-grade heat energy in the air to produce hot water or air that is higher than the ambient temperature. The operation of air source heat pumps is greatly affected by the temperature and humidity of the surrounding environment. When operating in cold regions or under extreme weather conditions, the system's low heating efficiency and frosting problems restrict its promotion scope and development speed. [0003] Existing heat pump systems mainly use a si...

AI Technical Summary

Problems solved by technology

However, for the two-stage compression cycle, due to the complex structure of the high and low pressure stage compressors and the intercooler, the connection method is complicated, there are many inlets and outlets with different functions, the inlets and outlets cannot be used in reverse, and it is difficult to realize the system pipe connection

At the same time, the temperature difference between the surface temperature of the evaporator and the ambient temperature is large, the defrosting time is long, the temperature fluctuation of the indoor environment is large, and the comfort of the indoor environment is low

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