Smoke low-temperature waste heat indirect heating heat supply network water supplement system and method

Abstract

The invention provides a smoke low-temperature waste heat indirect heating heat supply network water supplement system and method. The system comprises a coal-fired boiler, a dust remover, a wet desulphurization tower, a flash evaporation tower, an ejector, a steam turbine and a heat supply network heater. A smoke outlet of the coal-fired boiler is connected with an inlet of the dust remover, an outlet of the dust remover is connected with an inlet formed in the bottom of the wet desulphurization tower, and a desulphurized slurry outlet formed in the bottom of the wet desulphurization tower isconnected with an inlet of the flash evaporation tower. A clean smoke outlet is formed in the top of the wet desulphurization tower. A cold slurry outlet of the flash evaporation tower is connected with a cold slurry inlet formed in the top of the wet desulphurization tower, and a negative-pressure steam outlet of the flash evaporation tower is connected with an inlet of the ejector. A heat supply network water supplement inlet is formed in the ejector, an outlet of the ejector is connected with an inlet of the heat supply network heater, and a heat supply network water supply outlet is formed in the heat supply network heater. A steam outlet of the coal-fired boiler is connected with an inlet of the steam turbine, and a steam extraction opening which is formed in the middle of the steamturbine is connected with the heat supply network heater. The smoke low-temperature waste heat indirect heating heat supply network water supplement system and method are simple in structure, can improve the energy utilization efficiency, enhance the heat supply capacity of a unit, and have the remarkable economic benefit.

Description

technical field [0001] The invention belongs to the field of energy saving and emission reduction of thermal power generation, and in particular relates to a system and method for indirect heating of a heating network with low-temperature residual heat of flue gas. Background technique [0002] The smoke loss of coal-fired cogeneration units accounts for a considerable proportion of the calorific value of fuel, and reducing the loss of smoke exhaust can effectively improve the energy utilization efficiency of the unit. At present, the recovery of flue gas waste heat mainly adopts the method of partition wall heat exchanger. Since the coal-fired flue gas is ash-containing and acid-containing gas, it is easy to cause wear and corrosion of the heat exchanger, and the reliability of the equipment is generally poor. [0003] The wet desulfurization towers of most coal-fired cogeneration units are already close to the critical point of water balance, and low-temperature economizer...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to provide a system and method for indirect heating of flue gas with low-temperature waste heat and heat network replenishment, which can indirectly recover the waste heat of flue gas after wet desulfurization, reduce the amount of water replenishment in the heat network, solve the problem of water balance in the desulfurization tower, and at the same time reduce the amount of water in the flue gas. Water vapor content, eliminating the visual pollution of white plumes

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