Expansion valve opening controlling method for preventing oscillating of expansion valve

Abstract

The invention provides an expansion valve opening controlling method for preventing the oscillating of an expansion valve, which aims at solving the problem of valve oscillating caused by the factors that the regulating steps of the valve are fluctuated and a system is controlled misorderly due to the lagging influence of the system in existing expansion valve opening control. The expansion valve opening controlling method comprises the following steps of: S1. setting target superheat degree and standard valve opening; S2. initiating the valve, setting the valve opening as the standard opening after a compressor is started; S3. judging whether the starting time of the compressor achieves t1, and if yes, executing the S4; S4. determining the practical superheat degree of the valve after t1; S5. determining the superheat degree SH, controlling and regulating the valve opening of the expansion valve according to the difference delta SH between the current superheat degree SH and the superheat degree SH' at the last moment; S6. regulating the step number of the valve to be 1 or minus 1 after the compressor continuously runs for a certain time t (t is larger than t1) and within the time t2 after the absolute SH is equal to 0 and retreating is carried out; and S7. after the time t2, returning the S4. With the expansion valve opening controlling method, the valve oscillating phenomenon due to improper valve regulating steps can be avoided, and the system can safely and reliably run.

Description

technical field [0001] The invention relates to an air conditioner expansion valve, in particular to an expansion valve opening control method capable of preventing the expansion valve from oscillating and fluctuating. Background technique [0002] Inverter air conditioners generally use expansion valves to adjust the flow of refrigerant to meet the needs of precise, high-speed, and large-scale load adjustments. Usually, the difference between the temperature of the air return port of the compressor and the temperature of the indoor unit coil is used to calculate the superheat to control the expansion valve. The opening degree realizes the automatic adjustment of the refrigerant flow. [0003] The opening adjustment of the electronic expansion valve is driven by a stepping motor. The minimum angular range of the stepping motor is called one step. Therefore, the opening adjustment of the electronic expansion valve is generally measured by "step". For example, the opening of ...

AI Technical Summary

Problems solved by technology

[0005] The invention provides a method for controlling the opening of the expansion valve to prevent the oscillation of the expansion valve, which can solve the problem that the number of valve adjustment steps fluctuates up and down due to the rapid change of temperature and the influence of the hysteresis of the system in the opening control of the expansion valve in the prior art. The system control is disordered, causing the expansion valve to oscillate

Images