Joint heat regenerative system

Abstract

The invention discloses a joint heat regenerative system which comprises a high-pressure cylinder of a steam turbine, a main steam pipeline, a conventional last-stage steam extraction pipeline, an additional pipeline, heat exchangers, a feed water heater and a steam-side adjusting valve. The additional pipeline is additionally arranged on the main steam pipeline, main steam in the main steam pipeline is used as a heat source for the heat exchangers, exhausted steam of the heat exchangers is used as a heat source for the feed water heater, and the steam-side adjusting valve is arranged on the additional pipeline and is used for adjusting main steam in the additional pipeline, so that steam extraction pressures adjusted by the steam-side adjusting valve can be controlled, outlet temperatures of the feed water heater can be controlled, and requirements on ultimate feed water temperatures can be met. The joint heat regenerative system has the advantages that heat of steam of boilers can be recycled at starting phases of units by the aid of the joint heat regenerative system, and the problems of low pulverized coal burnout rates, black smoke of fuel oil and easiness in low-temperature moisture condensation, ash clogging, corrosion and the like of equipment such as air preheaters of tail flues in starting phases can be solved by the aid of the joint heat regenerative system.

Description

technical field [0001] The invention relates to the field of thermal power generation, in particular to a combined heat recovery system. Background technique [0002] At present, my country's electricity is mainly undertaken by thermal power generation units for peak regulation, 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 bo...

AI Technical Summary

Problems solved by technology

It takes about 8-10 hours for a traditional thermal power generating set to start from ignition to grid connection. During this period, a large amount of steam is sent to the condenser through the bypass system. Although the working fluid is recovered, the heat is lost.

In addition, there are still problems such as low pulverized coal combustion rate, black smoke from fuel oil, and air preheater in the tail flue, which are prone to low-temperature condensation, ash blocking, and corrosion during the start-up phase.

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