Control method for electronic expansion valve

Abstract

The invention provides a control method for an electronic expansion valve. When the outdoor environment temperature(Tho-A)is larger than or equal to 43 DEG C, opening of the electronic expansion valve is determined according to frequency change of a compressor. When the outdoor environment temperature(Tho-A)is smaller than 43 DEG C, the temperature is divided into different sections, and linear calculation curves of different target exhaust superheat degrees are set for each section; after the target exhaust superheat degrees and actual exhaust superheat degrees are obtained, fuzzy control is conducted, and then the opening transformation quantity of the electronic expansion valve is obtained. According to the section control method, fuzzy control is used, and different temperature ranges correspond to the calculation curves of the different exhaust superheat degrees, so that precise and optimal control is achieved. In addition, in combination with feedforward control technology, the reply efficiency of the electronic expansion valve is improved; accordingly, all air conditioner systems running in the different temperature ranges can run smoothly, and vibration is completely avoided. The control method has the advantages of being high in energy efficiency ratio, good in low-temperature heating effect, and the like.

Description

technical field [0001] The invention relates to a control method of an electronic expansion valve applied in an air conditioner. Background technique [0002] In the design of the air conditioning system, the electronic expansion valve is used as an electronic control component, and its opening is controlled by the superheat of the system to achieve the purpose of controlling the discharge temperature of the compressor. There are a wide range of applications in air conditioning. According to national standards, the operating temperature range of the air conditioning system is -7 to 43 degrees, and the frequency range of the inverter air conditioner is generally 15Hz to 110Hz. [0003] Most of the existing inverter air conditioner electronic expansion valves use PID control. The core logic of the mainstream PID control is the algorithm control of the electronic expansion valve at an outdoor temperature of 25 degrees to 36 degrees during cooling, and this algorithm is applied...

AI Technical Summary

Problems solved by technology

However, the operation of the air conditioner is very different under different external temperature conditions. At the same time, due to the large hysteresis and high nonlinearity of the air-conditioning refrigeration system, it is difficult for this control method to comprehensively consider all temperature ranges and establish an accurate mathematical model to control the electronic expansion valve. opening

At present, although there are also control methods by setting certain multiple values ​​and adding different multiples in different temperature ranges, it is still difficult to meet the superheat standard of the entire operating range

[0004] Moreover, in some Middle East regions, the ambient temperature reaches more than 50 degrees. When operating at such a temperature beyond the rated operating range, the load of the air conditioner changes greatly, and the cooling and heating effects of the air conditioner are difficult to satisfy.

Moreover, when the air-conditioning load changes greatly, the electronic expansion valve cannot respond in time, and the response is relatively slow, which will easily cause the entire system to vibrate, and even cause serious consequences such as component damage.

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