The Differential Pressure Method Flow Measurement Technology In Application Of Direct Fired Boiler

Primary air online monitoring of power plant boiler is of great importance to the boiler safety and economic operation, but the primary air in direct blow boiler due to carrying large amounts of coal, the wind speed measurement is actually the gas-solid two-phase flow measurement. With the development of gas solid two phase flow measurement technology, the technical problems of primary air online monitoring in direct blow boiler had also been studied and applied in many, but each had advantages and disadvantages in practical application. This paper aims to seek solutions to a simple but reliable and accurate.Through analysis of the measuring principle of two-phase flow based on differential pressure method, this paper puts forward the pulverized coal flow measurement project, parameters, environmental conditions and other basic measurement requirements, as well as the necessary condition to realize the accurate measurement of pulverized coal gas velocity. Based on the above analysis, selected the traditional differential pressure measurement model of the single phase flow as the theory foundation, designed and reformed the dust cleaning and abrasion proof structure of the measuring element. Through wind tunnel test, analysed the characteristics of wind speed measurement element, and improved the structure of the measuring element and monitoring system, in order to made it suitable for gas-solid two-phase flow velocity measurement, and applied to the primary air online monitoring in direct blow boiler.Through installing the measuring element in the technical transformation projects at the actual industrial field, building online monitoring system, programming the corresponding monitoring system software, to realized the primary air velocity data real-time processing and display of direct blow boiler pulverizing system. On this basis, calibration and Verification test was progressed when the boiler was in cold and hot state, which was to determine the actual use effect, and the test results and problems were summarized. Finally, further deepening and development on this subject was put forward.