Air source heat pump water heating unit and defrosting control method thereof

Abstract

The invention provides an efficient-defrosting air source heat pump water heating unit and a defrosting control method thereof. The air source heat pump water heating unit comprises a compressor, a condenser, an expansion throttling device, an evaporator, a gas-liquid separator and a controller, wherein an exhaust opening of the compressor is connected with an inlet of the condenser through a first electromagnetic valve, an outlet of the condenser is connected with an inlet of the evaporator sequentially through a drying and filtering device, a second electromagnetic valve, a one-way valve and the expansion throttling device, an inlet of the compressor is connected with an outlet of the evaporator through the gas-liquid separator, an outlet of the compressor is connected with an inlet of the expansion throttling device through a bypass electromagnetic valve, and the inlet of the expansion throttling device is connected with an outlet of the expansion throttling device through a third electromagnetic valve and a pore plate. The air source heat pump water heating unit provided by the invention is wide in application region range and high in defrosting efficiency, can be used for solving intractable problems resulting from a defrosting process in the prior art and can operate for a long term in a safe, efficient and stable manner.

Description

technical field [0001] The invention relates to the technical field of air-conditioning unit heating, in particular to an air-source heat pump hot water unit with high-efficiency defrosting and a defrosting control method thereof. Background technique [0002] As a national key energy-saving technology promotion project, heat pump energy-saving technology has been widely promoted in my country. In recent years, air-source heat pump water heaters have been more and more widely used in my country due to their energy-saving and safety characteristics. [0003] However, the promotion of air source heat pumps in the northern market of our country has been greatly restricted, mainly due to the constraints of climatic conditions. When the outside air temperature is too low, frost will form on the surface of the evaporator of the air source heat pump hot water unit, reducing the heat exchange effect, resulting in a decrease in heating capacity, and even the unit cannot start normall...

AI Technical Summary

Problems solved by technology

[0003] However, the promotion of air source heat pumps in the northern market of my country has been greatly restricted, mainly due to the constraints of climatic conditions.

When the outside air temperature is too low, frost will form on the surface of the evaporator of the air source heat pump hot water unit, reducing the heat exchange effect, resulting in a decrease in heating capacity, and even the unit cannot start normally

At present, the common defrosting methods include fin electric heating defrosting, hot water spray defrosting, hot air defrosting and four-way valve defrosting, the details are as follows: 1. Fin electric heating defrosting consumes a lot of power and does not save energy , part of the energy will be lost to the air, and it is easy to defrost when the ambient temperature is low; 3. In hot gas defrosting, if the working medium does not evaporate, it will not form gas, which will affect the suction of the compressor. If the suction is not good, the compressor will It is also difficult to return the oil, and poor oil return may burn out the compressor; 4. The four-way valve defrosting system in the reverse cycle defrosting stage, not only cannot provide heat to the room, but will absorb heat from the room, which affects the heating Operating efficiency, resulting in lower water temperature, and frequent reversing of the four-way valve will affect its reliability and life

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