The Development Of Thermal Expansion Valve Performance Automatic Detection And Control System

This project is sponsored by a company.The paper study deeply on the automatic adjustment of the static superheat value,and the detection of the general performance of TEV(thermal expansion valve).Based on the research,an automatic detection and control system of the performance of TEV is designed and developed.The main contents are as follows:(1)Firstly,the paper describes the working pr inc ip le and structure of t he TEV,as well as its importance in the regulat io n of air condit io ning and the limitat ions of artific ia l detection.The n determine the testing indexes of t he TEV genera l perfor mance a nd the auto mat ic adjust me nt o f t he static superheat value.The test ing indexes inc lude static superheat va lue test and leakage test.(2)Second,according to industr y standards and business needs,then make the design require me nts of t his syste m,put forward the overa ll design of t he TEV per for mance auto mat ic detectio n and contro l s yste m w hich inc ludes the control unit,pneumat ic unit,adjustme nt unit,temperature-controlling unit and software unit.The syste m software design inc ludes PLC software design and HMI software design.(3)This paper adopts motor wit h sensor techno logy to realize TEV static superheat auto mat ic feedback regulat ion.A iming at t he no nlinearit y a nd time-varying stat ic superheat va lue regulat ion,t he syste m introduces the dichoto my seeking va lue method in the control algor it hm,so that static superheat adjust and control to meet the beats,but also has a high adjust accuracy.Through a large number of experimenta l data to verify t hat the system meets the design requirements.(4)Fina lly,thro ugh the exper iment ver ifies the production cyc le of t his system,adjust-accuracy ver ificat ion.Then t he develop ment o f TEV performa nce wit h automat ic control syste m is eva luated by importing the machine capabilit y indexes.The mac hine capability indexes Cm.Cm k of this device are more than or equal to 1.67 which meet to the design requireme nts.