Low-temperature heating refrigerant flow rate matching control method and air conditioner

Abstract

The invention discloses a low-temperature heating refrigerant flow rate matching control method and an air conditioner. The low-temperature heating refrigerant flow rate matching control method comprises the following steps that S1, the air conditioner enters a heating mode, whether a condition of entering defrosting control is achieved or not is judged, and if the condition is achieved, S2 is executed; S2, the air conditioner performs defrosting operation, when defrosting is finished, an electronic expansion valve recovers an initial opening degree, defrosting timing is started, and after thedefrosting time is achieved with defrosting timing, S3 is executed; S3, valve regulation timing is started; S4, after a regulation time of the expansion valve is achieved with regulation timing, theelectronic expansion valve performs one-step valve closing, and whether the opening degree of the electronic expansion valve is declined to a lower limit opening degree or not is judged, and if the opening degree of the electronic expansion valve is not declined to the lower limit opening degree, S5 is executed; S5, whether the condition of entering defrosting control is achieved or not is judged,and if the condition is achieved, S6 is executed; S6, the opening degree of the electronic expansion valve is kept invariable; and S7, when the condition of entering defrosting control is achieved ornot is judged, the step S2 is executed, or otherwise, the step 6 is executed. By adopting the low-temperature heating refrigerant flow rate matching control method provided by the invention, the refrigerant flow rate in the defrosting process and the heat exchange ability of an evaporator perform dynamic matching, the low-temperature heating ability is improved, the defrosting period is prolonged, the energy consumption is lowered, noise pollution is reduced, and the use comfort is improved.

Description

technical field [0001] The invention belongs to the technical field of air conditioners, and in particular relates to a low-temperature heating and refrigerant flow matching control method and an air conditioner. Background technique [0002] At present, the flow control of the low-temperature heating electronic expansion valve of the inverter heat pump air conditioner is too rough. One is that the expansion valve is set to a fixed opening during the entire frosting process. At the beginning of frosting, the refrigerant flow through the fixed opening can meet the matching requirements of the heat exchanger. It is required that the refrigerant can be completely evaporated, but in the process of low-temperature heating and frosting, as the frost layer increases, the heat transfer capacity of the evaporator gradually decreases, and the fixed refrigerant flow rate cannot be completely evaporated, resulting in less and less refrigerant and heat transfer capacity. Matching makes t...

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Problems solved by technology

[0002] At present, the flow control of the low-temperature heating electronic expansion valve of the inverter heat pump air conditioner is too rough. One is that the expansion valve is set to a fixed opening during the entire frosting process. At the beginning of frosting, the refrigerant flow through the fixed opening can meet the matching requirements of the heat exchanger. It is required that the refrigerant can be completely evaporated, but in the process of low-temperature heating and frosting, as the frost layer increases, the heat transfer capacity of the evaporator gradually decreases, and the fixed refrigerant flow rate cannot be completely evaporated, resulting in less and less refrigerant and heat transfer capacity. Matching makes the capacity attenuate rapidly and deteriorates the use effect of the air conditioner; one is to adjust the electronic expansion valve once according to the change of the evaporation temperature during the low-temperature frosting process, but this adjustment range is often too large, which will cause the evaporation pressure and evaporation temperature to increase. Instantaneous mutations occur, resulting in rapid growth of ice crystals, destroying the stability of the system's frosting process, thereby shortening the frosting cycle, causing frequent defrosting of the air conditioner, and bringing discomfort

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