Start control method and system for variable-frequency air conditioner and air conditioner

Abstract

The invention relates to a start control method and system for a variable-frequency air conditioner and the air conditioner. The start control method for the variable-frequency air conditioner comprises the following steps that a target frequency Fd, a first frequency Fa and a second frequency Fb are set; a variable-frequency compressor is controlled to operate at the frequency Fa till a pressure difference is established, and a four-way valve of the variable-frequency air conditioner reverses; the frequency of the variable-frequency compressor is controlled to drop to the frequency Fb from the frequency Fa, the variable-frequency compressor operates at the frequency Fb for the time T1, and pressure buffering and preheating are conducted on the variable-frequency air conditioner; the target frequency Fd is compared with the frequency Fb, and the frequency of the variable-frequency compressor is controlled to directly drop to the target frequency Fd if the target frequency Fd is smaller than the frequency Fb; the second frequency Fb of the variable-frequency compressor is controlled to be stabilized at the target frequency Fb after frequency rising and frequency dropping are conducted multiple times if the target frequency Fd is larger than the frequency Fb. According to the start control method and system for the variable-frequency air conditioner and the air conditioner, frequency rising of an air-conditioning system can be achieved, and the situations that safe operation of the compressor is affected due to the fact that oil is excessively discharged during frequency rising of the compressor and other components of the system are damaged due to the fact that the pressure difference changes too rapidly are avoided.

Description

Technical field [0001] The invention relates to the field of air conditioning control, in particular to a start-up control method, a control system and an air conditioner of an inverter air conditioner. Background technique [0002] When the inverter compressor is started, it is often necessary to take into account the cooling / heating effect and the reliability of the compressor operation. The existing general starting method is to increase the compressor frequency step by step to achieve the cooling or heating effect. The step-by-step increase of the frequency of the inverter compressor, for some special harsh working conditions, such as ultra-low temperature heating, because of the hysteresis of the refrigerant flowing in the system, it will produce a larger pressure ratio, which will affect the compressor. Large abrasion can reduce the service life of the system; at the same time, reaching a higher frequency quickly will cause the compressor's oil discharge rate to be larger,...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide a start-up control method for an inverter air conditioner, a control system and its air conditioner, which solves the technical problem that the existing technology will cause large wear to the compressor and cause poor oil return in the system

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