The Research And Implementation Of Rapid Assessment Methods For Refrigeration Ability In The Small Refrigeration System

In this dissertation, a new assessment method for refrigeration abilityin small refrigeration system is studied. It estimates the refrigerationability through analyzing the curve characteristic of inlet and outlet pipetemperature in twenty minutes after starting. Standard curves whichdescribe the changing process of inlet and outlet pipe temperature in thesame model small refrigeration systems whose refrigeration ability areassessed as subcooled, normal and uncooled are created. After fitted byleast square method, inlet and outlet pipe temperature curves gained fromthe refrigeration system to be assessed are compared with standard inletand outlet pipe temperature curves in slope, curve similarity and so on.Based on it, the refrigeration ability is assessed. This method avoids thedisadvantage of consuming lots of time in testing and excludes the effectcaused by environment temperature and other external factors on the testresult. The whole test process can be finished in about twenty minutes.The method studied in this dissertation is demonstrated to be feasiblefrom aspects of theory and experiments. A least system that based on CAN-bus is designed and implemented to assess the refrigeration abilityof small refrigeration system. It can control eighty workstations at thesame time, and each workstation is a data acquisition terminal whichcontains six channels of temperature. The results of the A/D conversionare transmitted to the industrial control computer through CAN-bus. Theapplication software designed with Delphi 7 on industrial controlcomputer finishes drawing temperature curves, analyzing curves andassessing the refrigeration ability.