Cooling method of waste heat boiler inner wall during commissioning and blowing of gas-steam unit

Abstract

The invention relates to a method for cooling the inner wall of a waste heat boiler during adjustment of a blowpipe of a fuel-steam unit. The method comprises the steps that (1) a gas turbine turningmotor is started, and a gas turbine is made to turn at a low speed, specifically, the rotation speed is 8 rpm, and duration is 30 min; (2) an LCI system is started, the turning motor disengages and exits, and the gas turbine is turned at a high speed; (3) a smoke baffle at an outlet flue of the waste heat boiler is opened; and (4) wind power generated by an impeller of a gas turbine is blown towards the inner pipe wall of the waste heat boiler for cooling, the LCI system exits when the temperature of the inner wall of the waste heat boiler is decreased to be about 60-70 DEG C, the idling rotation speed of the gas turbine is gradually decreased to 0 rpm, and the smoke baffle is closed. With adoption of the method, the gas turbine turning at a high speed is used as an electric fan, the generated strong airflow is blown towards the inner pipe wall of the waste heat boiler for cooling, and the phenomenon of high temperature of the inner pipe wall of the waste heat boiler caused by variousreasons can be quickly and effectively solved.

Description

technical field [0001] The invention belongs to the technical field of safety of thermal power generation, and in particular relates to a method for cooling the inner wall of a waste heat boiler during debugging and blowing of a gas-steam unit. Background technique [0002] During the commissioning of the capital construction before the gas-steam combined cycle unit is put into production, in order to remove all kinds of sundries left in the superheater, reheater and steam pipeline during the manufacturing, transportation and installation of equipment and pipelines, the commissioning personnel must check the waste heat boiler Superheater, reheater, and steam pipes are blown, that is, steam flushing equipment and pipes. According to the "Guidelines for Steam Blowing of Thermal Power Construction Engineering Units", each waste heat boiler should be shut down for cooling at least twice during the blowing process. Each steam drum of the waste heat boiler should discharge water u...

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Problems solved by technology

[0003] When the operating personnel operate the steam drums of the waste heat boiler under pressure to discharge water during the shutdown cooling period, the temperature of the inner tube wall of the waste heat boiler will continue to be maintained at a relatively high temperature (80°C-100°C) due to various improper operations. The temperature difference between the inner tube wall of the waste heat boiler and the water is greater than 55°C. In such a situation, the temperature of the inner tube wall of the waste heat boiler can only be reduced to the appropriate temperature of the upper water by natural cooling at present, and it has not been able to achieve a rapid and effective reduction. The method of high temperature in the inner tube wall of the waste heat boiler caused by improper operation leads to the lack of necessary technical support for the safe operation of the gas-steam combined cycle unit during the commissioning blowpipe

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