Based On The Phase Difference Method Of Ultrasonic Heat Meter Measurement Technology Research

Under the time background of energy saving and emission reduction which is strongly advocated by the country, as well as strong demand in markets to achieve household heat metering, after extensive consult domestic and foreign relevant technical information and access to the research and development of heat meter production enterprise for research and practice, the author thinks that with the continuous improvement of the technology of heat meter, ultrasonic heat meter has become more in line with the present situation of domestic demand for household heating metering of heat measurement instruments. However, due to the design adopted by various manufacturers and design academy for ultrasonic heat meter is different, the finished products of the ultrasonic heat meter still exist many problems in some aspects such as heat metering accuracy and running stability.Considering that the heat flow measurement is the key to the target of accurate heat measure, while the measurement of interval time about the ultrasonic transducer sending and receiving ultrasonic is the core part of the flow measurement. In this paper, on the basis of making a comparison between the principle of time difference method and the principle of phase difference method of ultrasonic heat meter, then phase difference method is choosed for heat meter hardware system design and related software system programming. With low-power MSP430 processor as the core operation, through the flow measurement module in time-voltage conversion circuit, to realize the phase difference pulse signal measured by the front-end circuit which is in the form of voltage signal, by A/D transforming in MSP430 processor which is expressed as phase difference count data form, to represent propagation time difference, and ultimately to achieve accurate measurement of small time.After the completion of the sample heat meter produced, use the special detecting device of heat meter based on phase difference method of ultrasonic heat meter sample table to realize the actual measured flow information, then analysis the actual measurement data. By using MATLAB software to make the curve fitting of the different detected temperature points and the different flow points that obtained from the detection corresponding to heat meter display of phase difference data(namely tiny time), and make comprehensive curve fitting to the experimental data of a single sample heat meter, import the correction equation to the software system, correct the error of ultrasonic heat meter in actual operation. Reclosure the heat meter sample after error correction to the special detecting device for flow detection, so as to gain new experimental data. With other ways to compensate, make the flow measurement more accurate. Through the above work, with the other component detection, proved that the ultrasonic heat meter based on phase difference method can achieve the measurement of high precision, to realize the heat of accurate measurement ultimately.