Electronic expansion valve control system and method

Abstract

The invention discloses an electronic expansion valve control system which comprises sensors and a controller. A suction pressure sensor which is used for detecting suction pressure Ps and a suction temperature sensor which is used for detecting suction temperature Ts are arranged in a pipeline from an evaporator to a compressor, and an exhaust pressure sensor which is used for detecting exhaust pressure Pd and an exhaust temperature sensor which is used for detecting exhaust temperature Td are arranged in another pipeline from the compressor to a condenser; the controller takes a Ps signal, a Ts signal, a Pd signal and a Td signal collected through the sensors as criterion of control logic of the compressor and an electronic expansion valve. Accordingly, the advantages of controlling the degree of overheat of the suction and controlling the degree of overheat of the exhaust are combined, and at the same time the electronic expansion valve conducts control according to the suction pressure in a certain time after the compressor is stared up. The electronic expansion valve control system and method are used for controlling a water chilling unit, the stability of the electronic expansion valve control of the water chilling unit is guaranteed, the reliability of the water chilling unit is improved, and requirements of users for water chilling unit products are met.

Description

technical field [0001] The invention relates to the field of electronic technology, in particular to an electronic expansion valve control system, and also to an electronic expansion valve control method. Background technique [0002] With the development of domestic and foreign economies, there are more and more large-scale public buildings, factories, and residential applications, and a large number of places have strong demand for chillers. [0003] When people need chillers, the stability of the product is one of the basic requirements. Generally, according to the condensation method, chillers can be divided into water-cooled chillers and air-cooled chillers. Whether it is an air-cooled chiller or a water-cooled chiller, the main control components are the compressor, expansion valve (throttle device), etc., and the control of the expansion valve is very important in terms of system stability. [0004] Traditional expansion valves include electronic expansion valve (EXV...

AI Technical Summary

Problems solved by technology

[0011] The above-mentioned liquid level control method is characterized in that the opening of the electronic expansion valve EXV follows the change of the liquid level measured by the liquid level sensor, and the control of the electronic expansion valve EXV is more stable than the suction superheat or exhaust superheat, but its The disadvantage is that it is necessary to add a liquid level sensor to the system to sense the liquid level, which will undoubtedly lead to a substantial increase in cost

Generally, liquid level control methods are not used except in very important cases

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