Study On Prepaid Intelligent Heat Meter Based On MSP430

Now, regional central heating system has been well implemented in northern China's towns and cities, and heat meter is also having a good application in the system. Because of the heat meter's prices which are bought from foreign countries are very high, and they also can't meet national water quality, so it is very necessary to strengthen the research on the heat meter. The research purpose of this paper is to get some useful exploration in the heat calculation theory and practice of heat meter. A kind of low-power, high precision, multi-functional and high cost performance heat meter is designed according to the industry's latest standard of heat meter.Firstly, the composition of heat meter and its calculation principle are introduced in this paper. The hardware design process of heat meter and the device's selection process are defined, the detailed calculation process of heat meter's parameters are also given. Through ultra-low power MSP430 microcontroller and other low-power devices being used, and sharing-power supply technology and multi-interrupt mode are selected to achieve the system's low power consumption.Secondly, research focused on the important module of the heat meter. In order to improve the temperature acquisition unit's accuracy and efficiency, the mathematical model of the temperature acquisition unit which based on the least square method is established. The temperature unit's accuracy and reliability are very high because of using the distribution curve and the omission errors are exclude. The pre-paid unit which based on MF RC522 to solve the difficulty problem of charges of the heating centre. the"fist purchase hot, then use hot"consumption pattern is realized. In order to improve the efficiency of heat meter reading, a remote communication unit which has a multi-standard communication interfaces, multi-standard communication protocols is designed, and the heat meter's network capability is greatly enhanced. An external storage unit is designed to protect the user's thermal data, which is used to store user's thermal data periodicity. It is very convenient to query the user's historical datas.Finally, the system modules are tested, the data of the temperature acquisition unit and the flow collection unit are analyzed. The error data is given, the communication unit, IC card reading unit, display unit, storage unit and other units are also functionally verified. The results show that all the performances are meeting the design requirements.