Method for monitoring influence of water-cooled wall tube weld beading on tube wall safety

Abstract

The invention discloses a method for monitoring influence of water-cooled wall tube weld beading on tube wall safety. The method comprises the steps that three-dimensional flow and heat transfer calculation are conducted on a same-screen water-cooled wall under various load working conditions; the working medium flow and the tube wall temperature under each load working condition in the water-cooled wall are calculated by changing the shape of weld beading in a water-cooled wall tube and changing an area ratio parameter of the weld beading in the water-cooled wall tube, the tube wall temperature is compared with the allowable temperature of the water-cooled wall tube to obtain a safety margin of the water-cooled wall tube under each load working condition, and meanwhile, a relation characteristic that the safety margin of the water wall tube changes along with the change of the shape of the weld beading in the water-cooled wall tube and the area ratio of the weld beading of the water-cooled wall tube is obtained; a relation model among the weld beading shape, the weld beading area, the boiler load and the safety margin of the water-cooled wall tube is established based on a supportvector machine algorithm; and the water-cooled wall tube wall temperature and a unit load parameter which are acquired on line are compared with the water-cooled wall tube wall temperature calculatedby the water-cooled wall safety margin model, a thermal deviation condition of the water-cooled wall tube is determined, and the safety margin is monitored.

Description

technical field [0001] The invention relates to a method for monitoring the safety influence of water-cooled wall tube weld bumps on the tube wall, and belongs to the technical field of electric power and power engineering. Background technique [0002] Boiler water wall tubes are prone to welding bumps during butt welding. The shape and size of the welding bumps will cause changes in the fluid flow in the water wall tubes, thereby affecting the tube wall temperature and affecting the safety of the water wall tubes. Moreover, under different working conditions, the presence of weld bumps has different impacts on the safety of water-cooled wall tubes. Long-term overtemperature of the tube wall will cause the tubes to fail and burst, threatening the safe operation of the boiler. [0003] At present, the overtemperature monitoring of the tube wall is generally completed through the temperature measuring points installed on the water-cooled wall tubes. Since the temperature meas...

AI Technical Summary

Problems solved by technology

[0002] Boiler water wall tubes are prone to welding bumps during butt welding. The shape and size of the welding bumps will cause changes in the fluid flow in the water wall tubes, thereby affecting the temperature of the tube wall and affecting the safety of the water wall tubes.

In addition, under different working conditions, the presence of welding bumps has different impacts on the safety of water-cooled wall tubes. Long-term overheating of the tube wall will cause the tubes to fail and burst, threatening the safe operation of the boiler.

[0003] At present, the overtemperature monitoring of the tube wall is generally completed through the temperature measuring points installed on the water-cooled wall tubes. Since the temperature measuring points are installed on the backfire side, it cannot effectively reflect the temperature of the water-cooled wall tubes on the fire side. In addition, the temperature measuring points on the tube wall are generally It is only installed at one or two height positions of some water-cooled wall tubes, and cannot fully monitor the safety status of each tube

Images