Research On The On-line Heat Metering Device

With the reform of the heat supply system in China, the trend that the heat users are charged according to the heat consumption of every household has become inevitable. The heat meters are used to measure the heat absorbed or released in a heat flow loop. They are the basis for measuring the heat, and play the key role in the reforms of urban heat supply system and the charge methods.Usually, a heat meter is composed of flow meter, a thermometer and an integrating instrument. The measurement outcome of the traditional heat meters is accurate, but the demand to the water quality is relatively high, and their maintenance and management are very complicated. Besides, their costs are high enough on account of the need to the flow meters. On the other hand the installation of flow meters will have the original piping lines damaged, which is intolerable to the most of the heat users. The heat distribution meters are usually used abroad, although cheap and easy to install, they can not be used widely in China due to their low precision and inconvenient reading. Therefore, it becomes urgent working on a practical, cost-effective and easily installed heat metering device for the existing residential heat systems.Based on the theory of temperature difference correction, the on-line heat metering device is low-invested, easily installed, and the flow meter unneeded. It mainly includes the three parts: the terminal signals acquisition, data communication, and display and control in the base station. The part of the terminal heat signals acquisition implements the functions of acquisition of temperature signals, the dynamic correction of flow coefficients, and the heat integration and etc. by way of the low-power-dissipated microprocessor MSP430F149. The acquired heat signals are sent to the base station for the centralized display and control, with the wired and wireless, public network and the specialized one combined. The base station monitors and displays the heat values of all the users on-lined with the Samsung Corporation's ARM9 processor S3C2410 as its hardware platform, and the embedded Windows CE5.0 as its operating system. It also displays the real-time and historical heat curves, and stores and prints the data. The overall system realizes the charging task according to the household heat consumption.