Method for monitoring intra-furnace dynamic wall temperature in high-temperature tube system of power station boiler

Abstract

A method for monitoring the dynamic wall temperature inside the high-temperature tube system of a power station boiler in the technical field of power station boilers. The present invention obtains, through pre-calculation, the measurement and collection of the outer wall temperature of the representative furnace inner wall with the smallest temperature margin in the tube group. point; read the data required in the calculation of boiler real-time operation and furnace outer wall temperature from the real-time database of the power plant, and save it in the relational database of the local server; Real-time dynamic calculation of the working fluid temperature and metal wall temperature in the tube system of the reheater and reheater; the data of the metal tube section that exceeds the overtemperature value of the metal stress intensity of the tube wall is separated and stored in the overtemperature summary database. The invention effectively combines the dynamic online calculation and online monitoring of the actual working conditions, achieves the technical effect of prolonging the service life of the piping system, and solves the technical problem of preventing the boiler piping system from overheating and bursting.

Description

technical field [0001] The invention relates to a method in the technical field of power plant boilers, in particular to a method for monitoring dynamic wall temperature in a high temperature tube system furnace of a power plant boiler. Background technique [0002] In recent years, with the rapid development of my country's power generation industry, a large number of supercritical and ultra-supercritical generating units have been put into operation, and parameters such as boiler grade, temperature, and pressure have been improved. At present, metal materials have been used close to the highest temperature-resistant grade, and the corresponding materials have smaller and smaller margins in terms of stress over-temperature. Many factors will cause over-temperature phenomena during operation, and also cause internal oxidation due to material over-temperature. The generation of the skin is too fast and falls off, causing problems such as plugging and bursting tubes. Boiler t...

AI Technical Summary

Problems solved by technology

[0010] The disadvantages of this technology are: (1) As stated in the subject of this patent application, it only performs intelligent wall temperature management on the two tube groups of the final stage superheater and the final stage reheater of the utility boiler, while the large-capacity boiler The reheater piping system of the superheater has a total of 6 tube groups, namely the first-stage superheater (or low-temperature superheater), the second-stage superheater (or partition superheater), and the third-stage superheater (rear screen superheater). ), four-stage superheater (ie final stage superheater), low-temperature reheater and high-temperature reheater

In the actual operation of the boiler, about 30-40% of the over-temperature explosion occurs in the primary superheater and the secondary superheater. This patent does not involve solving the over-temperature explosion of the two tube groups of the primary superheater and the secondary superheater (2) In step 1 and step 2 of the patented method, there is no technical solution and measure for the selection of the measurement collection points for obtaining monitoring data and their layout, the accuracy and reliability of the relationship measurement value, so all The calculation of steam temperature and wall temperature at the calculation point (monitoring point) in the furnace lacks basis and is difficult to meet the actual operating conditions of the boiler. If the measurement collection point is not selected on the pipe with the highest temperature, or the accuracy of the measurement value is not high, the monitoring The calculation of the furnace steam temperature and wall temperature at the point will seriously affect the technical effect of the entire technical solution; (3) Step 3 in this technical method, the calculation model of the steam temperature and tube wall temperature at each calculation point also has a lack of modeling According to the situation that does not meet the actual operating conditions of the boiler, such as: the lack of radiation of the smoke chamber of the front pipe screen upstream of the calculation point (front and front radiation), the radiation heat of the radiation in the screen and the radiation behind the screen to the calculation point, and the lack of various Deviation of point convective heat absorption, radiation heat absorption between screens and radiation heat absorption in front of the screen calculated by row of pipes

To sum up, this patent cannot realize the fast online real-time calculation and online monitoring and control of the wall temperature of the entire power plant boiler tube system, nor can it realize the safe operation of the power plant boiler during its service period and prolong the service life of the boiler

Due to the lack of modeling basis and the problems of accuracy and reliability, it is difficult to obtain positive technical results for the specific final superheater and final reheater

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