A method of heating NOx water injection to improve the performance of combined cycle power plants

Abstract

The invention relates to a method for improving the performance of a combined-cycle power plant, and particularly relates to a method for improving the performance of a combined-cycle power plant by heating NOx injected water. The method is characterized in that an exhaust-heat boiler auxiliary equipment part in a closed cooling water system of a conventional combined-cycle power plant is an independent open cooling water system, and the rest of the closed cooling water system is correspondingly adjusted according to the quantity of circulating cooling water; demineralized water is supplied to the exhaust-heat boiler auxiliary equipment as cooling water by an independent pipeline, so as to exchange heat with a cooler matched with the exhaust-heat boiler auxiliary equipment and cool a cooling component of the auxiliary equipment, and additionally, the demineralized water is preliminarily heated; the demineralized water is further led to a chimney heater arranged in a chimney flue at the tail of an exhaust-heat boiler nearby and is heated by tail smoke to the maximum operating temperature permitted by an NOx water injection module of a gas turbine; and finally, the demineralized water is conveyed to the NOx water injection module of the gas turbine through a pipeline and is sprayed into a combustion chamber of the gas turbine, so as to participate in fuel combustion. On the premise that the NOx emission requirement is satisfied, the effects of absorbing dissipated heat of the auxiliary equipment and reducing the fuel consumption and the heat consumption rate are achieved, thereby improving the performance of the fuel combined-cycle power plant.

Description

technical field [0001] The invention relates to a method for improving the performance of a combined cycle power plant, in particular to a method for heating NOx injection water to improve the performance of a combined cycle power plant. Background technique [0002] Gas-steam combined cycle power plants mainly burn natural gas, light diesel oil and heavy oil and other fuels. In countries and regions that mainly use liquid fuels such as light diesel oil and heavy oil, it is necessary to make the gas turbine NO X Emissions meet environmental protection requirements, and gas turbines are usually equipped with NO X The water injection module is used to spray desalted water with qualified water quality into the combustion chamber to participate in combustion. In addition, combined cycle power plants are usually equipped with a closed-loop cooling water system to continuously absorb heat dissipation and cool auxiliary equipment from auxiliary equipment. Closed circulation cool...

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Problems solved by technology

[0007] However, the problem with this solution is that it is necessary to add a set of medium-pressure feed water heat exchanger and piping system to increase the initial investment. Moreover, the heater 11, as an independent device, needs to do a series of protective treatments and place the waste heat nearby. Near the boiler, in this way, the factory area needs to be increased for auxiliary equipment, and the practicability and applicability of the scheme are not high

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