Development of testing system for performance of thermal 

expansion valve for automobile airconditioning

 

 

 

DING Hao1, GU Xiaohong2, LAI Yufei1

 

(1. Zhejiang Institute of Quality Inspection Science, Hangzhou 310023, China;

 

2. College of Mechanical and Electrical Engineering, Hangzhou 310018, China)

 

 

Abstract: The thermal expansion valve is one of the important parts in automobile airconditioning, which affect the refrigerating effect, operation life and so on. Aiming at the weakness of current test methods and the lack of performance test system, the performances test methods were investigated for degree of superheat, interleakage and durability. The test methods for degree of superheat and interleakage were proposed based on the flow principle and differential pressure principle separately, and the time parameters for durability test were optimized. Meantime, a kind of testing system was investigated based on PLC control technology, in which the graphical programming language VB was used as control software development tool. The test system could implement automatic test of thermal expansion valve on the degree of superheat, interleakage and endurance performance according to standard testing requirements. The experimental results indicate that the proposed test methods can meet the primary performance test demand and the designed test system has higher measurement accuracy, test efficiency and automatic level for thermal expansive valve.

 

Key words: thermal expansive valve; performance test; PLC; testing system