The Research Of Constant Power Flow Measurement Based On The Thermal Diffusion

In modern society, the rapid development of science and technology, flow measurement technology in the industrial pipeline transportation and people’s lives have been widely used, more and more important role in the flow meter. Since conventional turbine flowmeter can not accurately detect a low flow velocity, and use will be a long time after a severe blockage scale, long-term stability is not easy to use, have a serious impact on production and life, this article is not for traditional instruments precise measurement of small flow defects, developed a new type of thermal mass flowmeters.Current research on thermal mass flow meters is divided into two areas: CTD mass flowmeter, mass flowmeter constant power. Measurement constant power flow measurement in the measurement of the pipe inserted into the two temperature sensors PT100, were used to measure the fluid temperature and speed, and the speed sensor constant power heating, the temperature difference between the two sensors to calculate the fluid velocity, since the measurement process using only two temperature sensors, the device does not need power, it almost does not affect the water flow rate. The design of the advantages and disadvantages of constant power and constant temperature differential flowmeter flowmeter detailed comparison shows that constant power mass flowmeter has more advantages.Through detailed analysis of constant power thermal mass flowmeter measurement principle is designed to TMS320F2812 as the core of the system of measurement circuit. The case for the current mass flow meter constant power control unstable power, the proposed fuzzy PID algorithm to control the digital potentiometer to ensure speed sensor heating power is constant, not only improve the measurement accuracy constant power meter, and it has a broader scope. Finally, the experimental design of the circuit is measured by the experimental results show that this system has on small flow measurement accuracy, wide measurement range, wide application of environmental advantages.