Air source heat pump system and control method thereof

Abstract

The invention provides an air source heat pump system and a control method thereof, and relates to the technical field of heat pumps. The air source heat pump system comprises a first subsystem and asecond subsystem; the first subsystem comprises a first compressor, a first condenser, a first gas-liquid separator, a first heat exchanger, a first throttle valve, a second throttle valve and a firstevaporator; and the second subsystem comprises a second compressor, a second condenser, a second gas-liquid separator, a second heat exchanger, a fourth throttle valve, a fifth throttle valve, a sixth throttle valve and a second evaporator. The air source heat pump system and the control method thereof can simultaneously conduct defrosting on the first evaporator in the case of continuous heating.

Description

technical field [0001] The invention relates to the technical field of heat pumps, in particular to an air source heat pump system and a control method thereof. Background technique [0002] The self-cascading air source heat pump cycle can achieve a high compression ratio, and can operate in a working environment with a large temperature difference, especially at a low ambient temperature, it can still provide hot water above 65°C, which can be widely used in people's production or Domestic heating or water. However, there are few studies on self-cascading air-source heat pump defrosting at present. When the existing self-cascading air-source heat pump cycle is heating in a low-temperature and high-humidity environment, the evaporator frosting phenomenon is more serious. When the frost on the evaporator is thick, it will lead to poor heating effect. If the traditional compressor exhaust is directly introduced into the evaporator for direct hot gas bypass defrosting, the de...

AI Technical Summary

Problems solved by technology

However, there are few studies on self-cascading air-source heat pump defrosting at present. When the existing self-cascading air-source heat pump cycle is heating in a low-temperature and high-humidity environment, the evaporator frosting phenomenon is more serious.

When the frost on the evaporator is thick, it will lead to poor heating effect. If the traditional compressor exhaust is directly introduced into the evaporator for direct hot gas bypass defrosting, the defrosting energy used only comes from the power consumption of the compressor. As a result, the defrosting speed is slow, and the liquid working medium produced by the evaporator cannot be evaporated after the hot gas defrosting, so it is easy to cause the compressor to absorb liquid during the defrosting process and cannot continue heating.

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