Design And Research Of Calibration Device For Large Diameter Heat Meter

With the reform of the heat supply system going quickly in China, there need more and more heat meters, the accurate measurement of heat energy and the scientifically rational price have become the focus of society. Heat Meter celibration device is used for production of business-to-heat table factory test, and also suitable for heating business and quality management department of the calorimeter of the first mandatory test, follow-up test and quality management department of the production enterprises in the table type of heat experiments and prototype experiments.At present, China already has the ability to product the small diameter heat meter and the celibration device, furthermore, its measurement accuracy and test accuracy have reached the international advanced level. However, study of greater than 50 large-diameter heat meter started late, although the country has to produce large diameter heat meter, large-diameter heat meter calibration device were in the initial stage, and rely on imports, while the price is too high, which prompted China's study, the R & D institutions have studied obtain the corresponding achievements, and test procedures are further improved.With the production capacity of large diameter heat meter, large-diameter heat meter calibration device for the beginning of a fruitful, based on national certification on the relevant provisions and requirements of heat meter. The PC and acquisition card are used to design the measurement and control system on the large-diameter heat meter based on LabVIEW in the paper.The main contents are as follows:First,the basic principles of heat meter calibration device are expounded;the small and large-diameter heat meter calibration devices are analyzed.Second, applicating U.S. NI's development platform virtual instrument (LabVIEW), hardware board (PXI-6281), MAX to configure PCI-6014 data acquisition card, ADAM-3013 isolated RTD input/out module and other hardware facilities, control hardware schematic are designed. It realizes the real-time acquisition of signals, data processing, data display, data management and output of control signal. The system has many strong points such as strong visibility, high real-time performance, friendly interface, easy operations and high visibility and so on, and the analog running proves that this system works stably and meets the demands.Third, there are many sensors which are used for measuring the data in the heat meter calibration device, 80% of the failure in calibration process are instrument failure. Above on the design fault diagnosis module, this paper sets up an automatic calibration and fault diagnosis system for large-diameter heatmeter, taking the LabVIEW virtual instrument as development platform using modulation designd and the rapid sensor fault detection algorithm, which decreases the uncertainty of measurement. The paper has realistic meanings to develop our calibration technology about heat meter and reform of heat measurement.The temperature stability of heating boiler to the accuracy of the calibration plays a key role, dual-mode controller is designed by introducting fuzzy control in original PI control and simulated by LabVIEW. The simulation results show that operating characteristics of Fuzzy-PI control, Fuzzy operating characteristics while maintaining the premise of the dynamic characteristics of the steady-state error with PI than under the control of the stability state error with an order of magnitude reduction can help reduce heat sheet verification process heat losses.Finally, the paper does summarizations, indicates the shortages and changing thinks in system design lading a foundation for further research. The work in this paper is helpful to end the history by import about large diameter calibration device and fill the gaps in our country, which will bring great contribution for reform.