Dry and wet state undisturbed switching system suitable for supercritical unit in deep peak regulation state and control method

Abstract

The invention provides a dry and wet state undisturbed switching system suitable for a supercritical unit in a deep peak regulation state and a control method. The dry and wet state undisturbed switching system comprises a water storage tank; an outlet is connected with a T-connector; an inlet is communicated with the outlet of a separator; a hot water circulation system is communicated with the outlet of the water storage tank and is configured to circulate saturated water in the water storage tank to an inlet of an economizer by adopting a hot water circulation pump; then the saturated water flows through a water cooling wall to reach the separator to realize working medium recirculation; a water level fine adjustment system for the water storage tank comprises a deaerator and a high-pressure heater which are communicated with the outlet of the water storage tank, and is used for leading saturated water of the water storage tank into the deaerator; and the saturated water is heated by the high-pressure heater, circulated to the economizer and the water cooling wall and then reaches the separator. According to the switching system, flexible conversion of a dry state and a wet state of the unit and long-period flexible peak regulation of 20%-100% load of the supercritical unit can be achieved; safe and stable operation of the unit is guaranteed; starting time and working medium and heat emission are reduced in the starting stage of the unit; and effective heat recovery is achieved.

Description

technical field [0001] The invention relates to the technical field of coal-fired generating sets, in particular to a dry-wet state disturbance-free switching system and control method suitable for supercritical generating sets in deep peak-shaving states. Background technique [0002] A coal-fired generator set is a mechanical device that converts the chemical energy of coal fuel into electrical energy. The working principle of the coal-fired generator set is to convert the heat energy generated by coal combustion into electrical energy through the power generation power device (power plant boiler, steam turbine, generator and its auxiliary devices, etc.). Coal-fired generating units are mainly composed of combustion system (with boiler as the core), steam-water system (mainly composed of various pumps, feed water heaters, condensers, pipes, water walls, etc.), electrical system (with turbine generator, main Transformer, etc.), control system and other components. The for...

AI Technical Summary

Problems solved by technology

Under low load conditions, when the unit is guaranteed to operate with a high superheat, it is very easy to cause overtemperature problems in the vertical pipe section of the water wall

In addition, it is difficult to adjust the degree of superheat under the low load condition of the unit. Therefore, it is very necessary to study how to conduct the non-disruptive switching between dry and wet states under the deep peak regulation state of supercritical units.

Images