Design Of Ultrasonic Heat Meter Based On MSP430 And TDC-GP21

Heat meter is the instrument used for measuring the heat consumption in heat exchange system, and displays time, quantity of heat, water temperature of inlet and outlet, serial number, or other information through the LCD. In recent years, with the quickening of the urbanization process in China, Urban heating system dominated by the government gets rapid development. Heating becomes more and more common, but in the process, some problems also appear, among them, waste heat is the most serious. The phenomenon is extremely unfavorable to low carbon environmental protection which is the concern of the whole society and the environment. Therefore, how to do heat economy become the most written topics. Traditional billing methods, according to the heating area, is the main cause of the waste heat. The only way to solve the problem is changing the billing methods, according to the head billing implement the realization of "one household and one table", this can not only avoid waste of resources, but also gives users more convenient with a clear understanding of their usage of heat, make the user and heating supplier understand each other.According to the working principle, the heat meter can be divided into mechanical, electromagnetic and ultrasonic heat meter, the mechanical and electromagnetic heat meter have obvious shortcomings, mainly for the mechanical wear, high power consumption, low accuracy of measurement. With the development of science and technology, ultrasonic heat meter solves the problems of the traditional heat meter, implement ultra-low power consumption, high precision, strong anti-interference ability, long service life.Ultrasonic heat meter, designed by this project, obtains fluid flow by using the theory of ultrasonic fluid velocity, measuring water temperature with the temperature sensor in pairs of inlet and outlet, finally, obtain the heat released through the heat exchange system by integrating instrument. Users can see the import and export temperature, flow, heat and other data clearly with the keyboard.This project, uses MSP430F417 ultra-low power MCU as the core processor, measures fluid flow and temperature of import and export with picosecond level high resolution TDC-GP21 which to be the dedicated time to digital conversion chip, and implements external communication through the M-BUS which to be special instrument bus. After the experimental verification, the accuracy of the ultrasonic heat meter can meet the state requirements, lower power consumption and the cost is effectively controlled.