High-pressure industrial heat supply method for thermal power plant

Abstract

Provided is a high-pressure industrial heat supply method for a thermal power plant. Optimization design is conducted on a large high pressure-intermediate pressure combined cylinder turbine generator set, and unconventional high-pressure industrial heat supply extraction steam is provided for heat consumers. The method specifically includes the following steps that a high pressure flow extractor 1 is shrunk to reach a high output flow area and an intermediate flow area, so that the pressure of the extractor 1 is about 10% higher than industrial heat supply extraction steam pressure when industrial heat supply steam is not extracted under a rated condition; consideration is given to reasonable feed-water temperature and a minimal pressure difference between the front and back of an intermediate regulating valve when heat supply extraction steam is rated; an industrial heat supply extraction steam opening is added to an extraction steam pipe of the extractor 1, namely, regenerative extraction steam and industrial extraction steam of the set are located in the same extraction opening, and meanwhile, a fast closing adjusting valve and a check valve are arranged on an industrial heat supply extraction steam pipeline; when loads of the heat consumers change, high output pressure is adjusted by changing the opening degree of the intermediate regulating valve, and therefore the pressure of the upstream separated extractor 1 is influenced and kept stable; the heat supply amount of the set is small, the extraction steam pressure is in a naturally pressure rising state, the intermediate regulating valve does not act, and the heat supply extraction steam pressure is kept stable through pressure reduction by a regulating valve on the heat supply extraction steam pipeline.

Description

technical field [0001] The invention relates to an industrial heating method of a thermal power plant, in particular to an unconventional high-voltage industrial heating method, which belongs to the technical field of thermal power generation. Background technique [0002] While generating electricity, thermal power plants also provide industrial heating to other thermal installations or provide heating and heating to cities. As far as industrial heating is concerned, the requirements for steam parameters are also different according to the heat load required by heat users. The industrial steam whose extraction pressure is about 1.0~2.5MPa can be adjusted by setting a seat cylinder valve in the steam turbine cylinder structure, and adding a butterfly valve on the rotating partition or connecting pipe. The door parameters are adjusted, and steam is extracted in the reheat hot section to meet the heating requirements. For industrial heating with higher parameters, such as ...

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Problems solved by technology

[0003] 1) The direct heat supply of small boilers is reliable and stable, but the combustion efficiency of small boilers is low, the economy is poor, the emission is difficult to meet the standards, the pressure on environmental protection is huge, and it is facing elimination, and it cannot provide electricity and has a single function

[0004] 2) The heat supply of the small back pressure machine is reliable and stable, but the steam comes from a small boiler, and the combustion efficiency of the boiler is also low, and the emission is difficult to meet the environmental protection standards. The conversion efficiency of through-flow is also low, and the economy is very poor

[0005] 3) The adjustment of the large high-pressure seat cylinder valve can realize the high-pressure adjustable heat supply of the large steam turbine unit. The unit sets the seat cylinder valve to adjust after the first pumping of the high-pressure flow, and the pressure response is sensitive; , The structure is complex, the high-pressure inner cylinder needs to be divided into two sections, and steam introduction and extraction devices are added, the seat cylinder valve has a new design, the upper half of the high-pressure outer cylinder needs to install the seat cylinder valve and bear its dynamic load, the rigidity of the cylinder is difficult to guarantee, and the design is difficult Large, long cycle; compared with the combined cylinder unit, one cylinder and one bearing box are added, even if the cost of a 300MW unit increases by more than 10 million yuan, and the length increases by more than 7m, the cost of the power plant building also increases

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