Multi-connected intelligent defrosting method

Abstract

The invention discloses an intelligent defrosting method for a multi-split air conditioner. The method comprises the following steps: (a) in a heating mode, after a compressor continuously operates by 5 minutes and the accumulated operation time reaches 40 minutes, the multi-split air conditioner enters a defrosting mode if the following conditions are synchronously satisfied in the following continuous 5 minutes: (1) Pd is not more than 19 bar; (2) Tdef is not more than C*Tao-alpha, wherein alpha is 8 DEG C; when Tao is lower than 0 DEG C, C is 0.8; and when Tao is not lower than 0 DEG C, C is 0.6; (b) if the condition (1) is satisfied and the condition (2) is not satisfied, the multi-split air conditioner enters the defrosting mode after the compressor continuously operates by 90 minutes; and (c) if the condition (2) is satisfied and the condition (1) is not satisfied, the multi-split air conditioner enter the defrosting mode after the compressor continuously operates by 90 minutes. The method has the following advantages: the multi-compressors can be normally used under different weather conditions in winter in the south and the north; and sending out a wrong defrosting instruction to the multi-split air conditioner by a controller can be effectively prevented.

Description

technical field [0001] The invention relates to a multi-connection system, in particular to a multi-connection intelligent defrosting method. Background technique [0002] The multi-connected air conditioner unit is referred to as multi-connected unit, which includes a controller, an outdoor unit, multiple indoor units connected in parallel, and two refrigerant circulation main pipes connecting each indoor unit and outdoor unit. The multiple indoor units are connected, and the controller is simultaneously connected with the outdoor unit and multiple indoor electromechanical devices connected in parallel. The outdoor unit includes a compressor, an oil separator, a four-way reversing valve, an outdoor heat exchanger (a condenser for cooling and an evaporator for heating) and a gas-liquid separator. The outlet of the compressor is connected to the inlet of the oil separator. The outlet of the oil separator is connected with the first valve port of the four-way reversing valve,...

AI Technical Summary

Problems solved by technology

Although the above multi-line defrosting method is simple, it also has the following defects: 1. Because the winter temperature in the north is generally low, the outdoor ambient temperature will be lower than the multi-line preset defrosting temperature for a long time or even all day long. Therefore, the temperature measured by the temperature sensor used to monitor the heat inlet temperature of the outdoor heat exchanger coil can easily meet the controller's standard for frosting of the outdoor heat exchanger coil, which will cause the multiple units to frequently enter defrosting We know that although the temperature in winter in the north is low, the outdoor air is relatively dry and there is less water vapor in the air. Therefore, after a long period of multi-line use, the frost on the heat exchanger coil of the outdoor unit will not be too serious. It will not affect the normal use of the multi-connector, so the frequent entry of the multi-connector into the defrosting mode will cause frequent fluctuations in the indoor temperature, which will easily cause discomfort for customers; 2. Compared with the north, the temperature in the south is generally cooler in winter. High, the outdoor ambient temperature will be higher than the defrosting temperature preset by the controller for a long time or even all day long, so the temperature measured by the temperature sensor used to monitor the heat inlet temperature of the heat exchanger coil of the outdoor unit is difficult to control However, due to the high humidity of the outdoor air in the south, after using the multi-line for a long time, the frost on the heat exchanger coil of the outdoor unit tends to increase. Serious, which will affect the normal use of the multi-line; 3. The temperature sensor used to monitor the heat inlet temperature of the heat exchanger coil of the outdoor unit may drift after long-term use, which will directly lead to control failure. Due to the wrong temperature signal received by the controller, the multi-split unit will issue wrong commands, which will affect the normal use of the multi-split unit. For example, when the heat exchanger coil of the outdoor unit does not need to defrost, the multi-split unit will switch from heating mode When entering the defrosting mode, or when the heat exchanger coil of the outdoor unit needs to be defrosted, the multi-split unit cannot enter the defrosting mode