Electronic expansion valve control method and device and refrigerating system

Abstract

The invention relates to an electronic expansion valve control method and device and a refrigerating system. The control method comprises the steps of obtaining the temperature difference Tp of the ends of an evaporator; comparing Tp with a control target value Ts of the temperature difference of the ends of the evaporator, so that a difference value delta Tp of Tp and Ts is obtained; according to the comparison relationship between delta Tp and a preset deviation value, determining an opening degree value of an electronic expansion valve; and controlling and adjusting the opening degree of the electronic expansion valve to reach the determined opening value. According to the electronic expansion valve control method and device and the refrigerating system, the real-time value of the temperature difference Tp of the ends of the evaporator is detected, and the real-time value of Tp is compared with the control target value Ts of the temperature difference of the ends of the evaporator, so that if the difference value delta Tp between Tp and Ts is greater than the allowed deviation value, the opening degree of the valve is increased; and if the difference value is smaller than the allowed deviation value, the opening degree of the valve is decreased, and thus variation of the opening degree of the electronic expansion valve is adjusted; the most proper liquid supply amount is provided for the evaporator; and the temperature difference Tp of the heat exchange ends of the evaporator is lowered to the minimum, and it is guaranteed that heat exchange performance of the evaporator is brought into the fullest play.

Description

technical field [0001] The invention relates to the technical field of air conditioning, in particular to a control method and device for an electronic expansion valve and a refrigeration system. Background technique [0002] The throttling structures commonly used in refrigeration systems include orifice plates, thermal expansion valves, electronic expansion valves, etc. Due to the working principle, orifice plates and thermal expansion valves are not suitable for flooded and falling film evaporators. For refrigeration cycle systems using flooded and falling film evaporators, electronic expansion valves are usually used as throttling structures, which can achieve high-precision, approximately linear refrigerant liquid supply control. The control method is generally to control the exhaust of the compressor. The superheat is within a certain range. [0003] However, the limitation of using the exhaust superheat as the control target is that: the most reasonable target value ...

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Problems solved by technology

[0003] However, the limitation of using the exhaust superheat as the control target is that: the most reasonable target value of the compressor exhaust superheat varies greatly under different operating conditions and compressor loads, resulting in the inability to achieve the optimum refrigerant liquid supply into the evaporator , the capacity of the evaporator cannot be fully utilized

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