Research On Furnace Temperature Measurement By Acoustic Technologies

Our country's thermal power generating capacity accounted for about 70% of the total installed capacity, and in the next period of time, thermal power based pattern will not change.In large thermal power plant, the combustion conditions of the boiler furnace unreasonable will lead to overheating, heating surface of furnace tube leakage and furnace coking etc, good combustion conditions can improve combustion efficiency, reduce coal consumption and reduce emissions. Therefore, the effective monitoring and control of the combustion temperature field in the furnace directly affect the safety and economy of the unit.However, the environment in the furnace is bad, which has the characteristics of high temperature, dust, turbulence and so on, Lack of real-time, accurate and comprehensive methods to obtain temperature information for a long time. Therefore, it is very important and urgent to find a new method which can be applied to the above characteristics. Acoustic method as a non-contact method for high temperature measurement has recently been concerned, This paper based on the 600 MW boiler, power plant as the research object, research on engineering application of acoustic pyrometry.First, the acoustic sound field characteristics in a power plant boiler is carried on simulation study, The results show that the air is the medium of the enclosed space in the boiler, which is not operated at room temperature. Sound acoustic temperature measurement equipment, across the border will sound reflection, space will stimulate a great deal of standing wave, standing wave superimposed on each other, the acoustic energy tends to be uniform in all directions, generating a reverberation sound, forming a diffuse sound field, acoustic travel time measurement will consider the reverberation factor.Then, according to the actual layout of the boiler, it is suggested that the location of the central position of the furnace is arranged in the middle of the furnace, and the edge of the observation point is arranged at the edge of the observation point, and the arrangement of the measuring points of the 24 paths is taken by 4 launched and 8 received. Such optimization arrangement, which is combined with the actual situation of the boiler, the spatial resolution of the sound, the 4 time to form a measurement cycle, but also can greatly improve the system time resolution.Finally, the boiler is installed on a 600 MW unit, and the boiler is running under normal temperature and thermal state, and the furnace outlet temperature is obtained. The furnace temperature field visualization is realized by the satisfactory temperature map of the furnace, the temperature display and the isotherm diagram. The use of infrared thermometer for the acoustic temperature measurement system for the initial calibration, measurement results accurate and reliable.