Adjustable joint heat regenerative system

Abstract

The invention discloses an adjustable joint heat regenerative system which comprises a high-pressure cylinder of a steam turbine, an additional adjustable rear last-stage steam extraction opening in the high-pressure cylinder, heat exchangers, an additional adjustable rear last-stage feed water heater, an additional adjustable rear last-stage steam extraction pipeline and an adjustable steam extraction adjusting valve. Additional adjustable rear last-stage extracted steam of the high pressure cylinder is used as a heat source for the heat exchangers, and exhausted steam of the heat exchangers is used as a heat source for the additional adjustable rear last-stage feed water heater; the adjustable steam extraction adjusting valve is arranged on the additional adjustable rear last-stage steam extraction pipeline. The adjustable joint heat regenerative system has the advantages that the additional adjustable rear last-stage extracted steam can be exhausted to the additional adjustable rear last-stage feed water heater to further additionally heat feed water after hot secondary air of boilers or / and hot primary air of the boilers or / and fed powder of the boilers are heated by the heat exchangers, accordingly, the superheat degree of the last-stage extracted steam can be effectively utilized, the hot secondary air of the boilers or / and the hot primary air of the boilers or / and the fed powder of the boilers can be heated, output of powder manufacturing systems can be enhanced, the combustion stability and the combustion efficiency of the boilers can be enhanced, and the cost further can be reduced.

Description

technical field [0001] The invention relates to the field of thermal power generation, in particular to an adjustable combined heat recovery system. Background technique [0002] At present, my country's electricity is mainly regulated by thermal power generation units, and low-load operation of thermal power generation units has become the norm. With the official release of my country's "Thirteenth Five-Year Plan for Electric Power Development (2016-2020)", "strengthening peak peak capacity building and improving system flexibility" has become one of the important tasks of thermal power generating units, which means that the thermal power The deep peak shaving and system flexibility of the generating set put forward higher requirements. In fact, the thermal power generating set operates at low load, and there are many problems such as environmental protection, safety, and economy, including the need to withdraw the operation of the SCR denitrification device, the boiler Hydr...

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Problems solved by technology

[0004] However, the system and method provided by this patent still have deficiencies. At each load stage of the unit, the extraction steam of this stage needs to be throttled to maintain the pressure of the extraction steam regulating valve, especially at lower loads, the extraction steam superheat will be relatively large, resulting in a large heat transfer temperature difference of the additional feed water heater and an increase in irreversible losses. High, it will lead to an increase in the cost of the corresponding pipes and feed water heaters, especially with the continuous improvement of unit parameters, such as 700 ℃ units, due to the corresponding high extraction temperature, it will make it difficult for the feed water heater to meet the current manufacturing process. accomplish

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