A method for controlling low-temperature refrigeration of an air conditioner

Abstract

The invention provides a method for controlling low temperature refrigeration of an air conditioner. The method comprises the following steps: (1) measuring middle temperature T3 of an outer unit condenser; (2) comparing T3 with first preset values T1 and T3 and a second preset value T2 respectively, wherein T1 is greater than T2; (3) when T3 is greater than T1, raising output voltage U of an external motor so as to increase the rotating speed of an external fan; when T3 is smaller than T2, decreasing the U so as to reduce the rotating speed of the external fan. According to the method for controlling the low temperature refrigeration of the air conditioner, the output voltage U of the external motor is adjusted according to the middle temperature T3 of the condenser so as to adjust the rotating speed of the external fan, and then the T3 is stabilized in a range of T2 to T1. The T3 can reflect the system operation pressure of the air conditioner better, thus the T3 stabilized in the certain range can ensure the working pressure of the condenser, thus the system operation pressure is controlled better; therefore, stable operation of the system is ensured during the low temperature refrigeration of the air conditioner, thus the start and stop times of a compressor are reduced, and the comfort of room is improved.

Description

technical field [0001] The invention relates to the technical field of air-conditioning equipment, and more specifically, relates to a control method for low-temperature refrigeration of an air-conditioner. Background technique [0002] In western countries and regions, many high-end restaurants and bakeries have high requirements for indoor air comfort and cleanliness. In winter, because the heating is turned on indoors, and there is a bread oven in the room and the heat generated by the restaurant kitchen is large, the indoor temperature is easy to rise. In addition, such high-end restaurants and bakeries cannot open windows to cool down. Therefore, it is necessary to install an air conditioner with a low-temperature refrigeration function to cool down the indoor air. However, for ordinary air conditioners, the outdoor temperature range of their cooling operation is 21-43°C, which cannot meet the requirements of reliable cooling operation in such a low temperature enviro...

AI Technical Summary

Problems solved by technology

[0005] However, since the above-mentioned low-temperature refrigeration module regulates the low-temperature refrigeration of the air conditioner, it adjusts the output voltage of the external motor according to the outlet temperature of the condenser of the external unit of the air conditioner, so that the pressure of the condenser fluctuates greatly, making it difficult to ensure stable operation of the system, resulting in The compressor is easy to switch on and off frequently, the indoor temperature fluctuates greatly, and the comfort is poor

[0006] At the same time, due to the unstable operating pressure of the system, liquid-filled operation is prone to occur, and the system reliability is poor

[0007] In addition, under different outdoor ambient temperatures, the output voltage range of the outdoor fan is the same, and the speed adjustment range is the same, which may easily lead to frequent adjustment of the speed of the outdoor fan. During the adjustment process, the system is prone to vibration, which affects the stable operation of the system.

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