Pump-free direct current furnace starting system capable of recycling working medium and heat comprehensively

Abstract

The invention relates to a pump-free direct current furnace starting system capable of recycling a working medium and heat comprehensively, and provides a direct current furnace starting system which is used for a supercritical direct current furnace without a starting furnace water circulation pump at a power station and can recycle the working medium and heat comprehensively. According to the invention, during the starting period of the direct current furnace, three high-pressure heaters at the side of a turbine are utilized as a water heat exchanger, heat is emitted in echelon by the starting of the drainage with high enthalpy, pressure is reduced, thus the enthalpy is reduced to be suitable for the safe recovery by a deaerator; double control logic of the high-pressure heater by a machine set DCS (data conversion system) with special design ensures each high-pressure heater to complete the starting whole process of the direct current furnace and a heat regenerative system working pattern safely and economically under two different working patterns; the working medium and heat can be recycled comprehensively by each starting working condition and starting whole process, and therecycled effect is superior to the direct current furnace starting system with a starting furnace water circulation pump; and the maintaining expense of the infrastructural construction investment and operation can be reduced greatly by the starting furnace-free circulation pump and a subsystem thereof.

Description

(1) Technical field: [0001] The invention relates to a pumpless DC furnace start-up system capable of fully recovering working fluid and heat, which relates to a DC furnace starting system capable of fully recovering working fluid and heat without using a water circulation pump for starting a supercritical DC furnace of a power station. (two) background technology: [0002] The start-up system of the supercritical once-through boiler of the power station in the prior art is an important part of the supercritical once-through boiler of the power station. The purpose of setting up the start-up system is to establish and maintain the water-cooled wall through the start-up system during the boiler start-up, low-load operation and shutdown process. The minimum mass flow rate within the unit is used to protect the safety of the water wall; at the same time, it meets the requirements of safe and economical start-up and shutdown of the unit; low-load operation of the unit, rapid acci...

AI Technical Summary

Problems solved by technology

[0008] Type A once-through furnace start-up system is generally considered to be able to fully recover the working medium and heat except for a few minutes during the expansion period of the once-through furnace when the boiler water circulation pump is started to work normally. Pipelines and valves are protected from excessive thermal shocks. Since the ignition of the DC furnace, about 20% of the start-up flow has been sent to the atmospheric drain expander, and this part of the working medium and heat are basically lost; It can still start the DC furnace safely when it fails, but it has degenerated into a C type DC furnace starting system

[0009] Type B once-through furnace start-up system is generally considered to be able to fully recover working fluid and heat except for a few minutes during the expansion period of the once-through furnace when the boiler water circulation pump is started to work normally. The pipeline is protected from excessive thermal shock, and about 20% of the start-up flow has been sent to the condenser since the ignition of the once-through furnace, and this part of the heat is basically lost; when the water circulation pump of the start-up furnace fails, the once-through furnace can still be started safely , but it has degenerated into D type DC furnace start-up system

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