Deep peak regulation dry and wet state switching system for supercritical boiler

Abstract

The invention discloses a deep peak regulation dry and wet state switching system for a supercritical boiler, which comprises a multi-stage flow limiting device and a flash tank, after the supercritical boiler is switched to a wet state, high-temperature saturated water flows through the multi-stage flow limiting device through a pipeline for pressure reduction, and then enters the flash tank; expansion steam generated after expansion evaporation in the flash tank is divided into two paths, namely a first pipeline and a second pipeline, and the expansion steam in the first pipeline is drained to a steam inlet pipeline of a second high-pressure heater through a pipeline so as to replace part of extracted steam of the second high-pressure heater to heat feed water. The method is suitable for the supercritical boiler without a boiler water circulating pump to be converted from a dry state to a wet state for operation, and full recovery of working media and heat after the supercritical boiler is converted into the wet state for operation and continuous operation after deep peak regulation is converted into the wet state are achieved.

Description

technical field [0001] The application belongs to the technical field of heat supply and energy saving for thermal power generation equipment, and in particular relates to a deep peak-shaving dry-wet state switching system for a supercritical boiler. Background technique [0002] In recent years, with the rapid growth of my country's power generation installed capacity, especially the rapid development of new energy power generation, in order to better accommodate new energy power generation, it has become normal for large thermal power units to participate in deep peak-shaving operations. Affected by factors such as power peak regulation, as the load rate of the unit decreases, when the unit is deeply peaked to a lower load (below 30% load), the boiler of the supercritical unit will have a dry-wet transition phenomenon. During the dry-wet state switching process of the boiler, many systems are involved, the system is complex, and there are many equipment operating procedure...

AI Technical Summary

Problems solved by technology

Affected by factors such as power peak regulation, as the load rate of the unit decreases, when the unit is deeply peaked to a lower load (below 30% load), the boiler of the supercritical unit will have a dry-wet transition phenomenon. During the dry-wet state switching process of the boiler, many systems are involved, the system is complex, and there are many equipment operating procedures. When the operation is improper, frequent dry-wet state switching, hydrodynamic instability, and violent fluctuations in unit parameters will easily occur, resulting in equipment failure.

There may even be accidents such as overheating of the heating surface, explosion of the tube, water inflow of the superheater caused by the separator being full of water, etc., seriously endangering the safe operation of the unit

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