Refrigeration System Comprehensive Test Instrument

With the rapid development of science and technology,the application of refrigeration system is more and more widely,the use of refrigeration equipment is increasing,the demand for refrigeration system maintenance is increasing day by day.Maintenance and fault analysis of the refrigeration system will help to improve the efficiency of refrigeration equipment,service life and energy saving effect.Maintenance of the refrigeration system need to carry a large number of tools and manual data recording,resulting in refrigeration system fault analysis time-consuming,maintenance costs.In view of this,developed for refrigeration system fault detection instrument has important significance.Based on the theoretical research of vapor compression refrigeration cycle and the analysis of actual demand,the intelligent instrument of refrigeration system can be achieved on the refrigeration system parameters of the measurement and analysis.The instrument has a refrigeration system parameter measurement,vacuum testing,air tightness testing and refrigerant charging and other testing methods.The thermodynamic parameters and performance parameters of the refrigeration system can be obtained by the combination of pressure enthalpy,temperature entropy,saturation vapor and thermodynamics equations,which can be used to measure the supercooling temperature,superheat temperature,vapor pressure and condensing pressure.The hardware and software design,data processing method,function realization and performance test of the intelligent instrument are discussed in detail.The design of the hardware circuit mainly includes the design of the main control module,the peripheral integrated data acquisition module,the USB communication module,the key and the display module,and the power supply module.The software design follows the modular programming idea,completes the main program,the function program,the driver program.In the process of data processing,the first-order inertia filter and Kalman filter are designed by analyzing the time-domain and frequency-domain of the sampled-value signal.In the process of data processing,the first-order inertia filter and Kalman filter are designed by analyzing the time-domain and frequency-domain of the sampled-value signal.After the prototype development is completed,various functions and performance tests were carried out.The test results show that the temperature measurement error is ± 0.3?,the pressure measurement error is ± 0.35% FS,the functions and performance indicators meet the requirements.