The Research Of Intelligent Detecting Systerm For Heat Meter

The domestic need for heat meters is exploding because of the heating system reform and the enforcement of the policy about household heat metering with central heating. As the national key management of measuring instrument, heat meters have the equal status of household water meter, gas meter and electric meter. Therefore, the verification of heat meter accuracy is more and more urgent.At present, two kinds of verification methods were commonly used in heat meter calibration device: constant velocity method and constant pressure method. Constant velocity method using high precision flow meter and variable frequency pump form a single closed loop system, realize the flow stability, but due to the pressure loss in the pipeline, the flow rate is low, so the test result is poor. Constant pressure method using pressure tank, pressure sensor and frequency pump form a single closed loop system, realize the pressure stability of the inlet. However, we need to manually adjust the valve opening of the water outlet end in the calibration system, so that the flow rate can meet the requirements. In addition, the manual adjustment valve is very frequent, verification efficiency is very low. For that reason, this paper proposes a two-parameter system. A closed-loop system which consist of pressure tank and frequency pump was designed at the inlet of the device, this system can adjust the inlet pressure of the calibration device. A closed-loop system which consist of high precision flow meter and electronic flow control valve was designed at the outlet of the device, this system can adjust the size of the flow. This design can guarantee a stable flow and a constant pressure. This design not only can ensure the constant pressure of the device but also can guarantee a stable flow of the device.The study includes the following aspects: Firstly, analyzes the technical indicators of the heat meter calibration device and the common heat meter test methods. By analyzing the advantages and disadvantages of each test method, to determine the design scheme of two-parameter intelligent heat meter calibration device. Secondly, introduced the hardware design of the heat meter calibration device in detail, and introduces the selection scheme of the main devices. In addition, simulated the state change of the liquid when flow into the heat meter by Solid Works software, proved the necessity of a steady flow tube,and determined the shortest length of the steady flow tube. Then, introduced the upper-computer software of the heat meter calibration device. The upper-computer software mainly consists of several parts, including login system, main menu, operator management system, modify the operator information system, heat meter calibrate system and data management system. Finally, analysis of the uncertainty of heat meter calibration device, the results showed that the device arrived requirements.