Energy gradient efficient utilization system of supercritical coal-fired generator set

Abstract

The invention relates to an energy gradient efficient utilization system of a supercritical coal-fired generator set. The energy gradient efficient utilization system is characterized in that air is heated by utilizing superheat degree energy of steam extraction on the side of a steam turbine of the supercritical coal-fired generator set, so that the heat exchange temperature difference between steam and water in a regenerative heater is effectively reduced, and the irreversible loss is reduced; one part of the heated air provides enough oxygen for a boiler to enter a hearth to participate incombustion; and the other part of air can be continuously utilized to heat feedwater and condensed water, so that part of backheating extracted steam extracted from a steam turbine is squeezed, and correspondingly, the squeezed backheating extracted steam returns to the steam turbine to continuously expand and do work, therefore, under the condition that the amount of coal input in the boiler is not changed, the total work of the steam turbine is increased, the power generation capacity is increased, and the power generation efficiency of the unit is improved. And on the other hand, heat absorption of air in a tail flue is reduced on the boiler side, the amount of fuel needed by the boiler side is reduced, and the purposes of energy conservation and emission reduction are achieved. The energy gradient efficient utilization system is reasonable in structure, high in applicability and good in effect.

Description

technical field [0001] The invention relates to a coal-fired generating set, in particular to a system for energy cascading and high-efficiency utilization of a supercritical coal-fired generating set. Background technique [0002] In my country's primary energy consumption structure, the proportion of coal has remained above 70% for a long time, and the amount of raw coal consumed by coal-fired power generation has exceeded 50% of the domestic coal consumption. In addition, with the large-scale development of renewable energy such as wind energy and solar energy, coal-fired power generation still occupies the dominant position in my country's energy structure. Coal-fired power generation units have the advantages of controllable power supply load, little impact on the natural environment, and relatively mature technology. . However, with the increasingly serious environmental pollution and the lack of fossil energy year by year, as a provider of clean energy and an emitter ...

AI Technical Summary

Problems solved by technology

However, the energy on both sides of the boiler and steam turbine of the coal-fired power generation unit has not yet been fully utilized, and the energy loss caused by the high superheat of the steam turbine extraction is still very large due to the mismatch of energy levels

As the working medium necessary for combustion, air directly exchanges heat with high-temperature flue gas, and the heat exchange temperature difference is large, resulting in large irreversible losses during the heat transfer process.

For the in-depth optimization of the thermal system of supercritical coal-fired power generation units, there is no effective high-efficiency utilization system in the existing technology

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