Isentropic air heat exchangers for boilers

Abstract

The invention discloses an isentropic air heat exchanger of a boiler, which is characterized in that a heat release piping line is additionally arranged in the air duct of the boiler, a heat absorbing piping line is additionally arranged in the inlet gas flue of the boiler, a plurality of groups of fin plates are fixedly arranged on the two sides of the heat absorbing piping line and the heat release piping line, the heat absorbing piping line and the heat release piping line form a circulating system through pipelines, a plurality of headers and valves, one header of the heat absorbing piping line is connected with the inlet header of a coal economizer of the boiler through a pipeline and a water inlet valve, and the header is provided with a drain pipe and a drain valve; a steam exhaust pipe is arranged on the heat release inlet header of the heat release piping line and a steam exhaust valve is arranged on the steam exhaust pipe; and the heat release piping line and the header of the heat release piping line are higher than the heat absorbing piping line and the header of the heat absorbing piping line. The isentropic air heat exchanger of the boiler has the advantages that the heat loss during flue gas exhaust is greatly reduced, the temperature adjusting capability of the air-flue gas system of the boiler is increased, the thermal efficiency of the boiler is improved, the problems of cyanamide sulfate corrosion, blockage and the like caused by denitration are thoroughly solved and the energy consumption of the boiler is reduced.

Description

technical field [0001] The invention relates to an air heat exchanger for a boiler. Background technique [0002] At the Copenhagen Conference in 2004, China announced that by 2020, China's carbon emissions will be reduced to 40% of the carbon emissions in 1996. Since SCR denitrification technology is commonly used in boilers at present, the so-called SCR denitrification technology is to install a denitrification device in the inlet flue above the rotary air preheater after the boiler economizer, and use the flue gas temperature of 300 ℃ ~ 400 ℃ after the boiler economizer. Under the action of the catalyst, the diluted ammonia gas is injected to chemically react with the nitrogen oxides in the original flue gas to generate nitrogen and water vapor, thereby reducing NO X emission! Due to the limitations of denitrification technology, the design allows ammonia escape of ≤3ppmV. In terms of operation, there is currently no reliable operation method to control ammonia escape w...

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Problems solved by technology

[0003] The object of the present invention is to address the above-mentioned deficiencies in the prior art, to provide an isentropic air heat exchanger for a boiler, which can not only greatly reduce the heat loss of the exhaust gas, increase the temperature adjustment ability of the boiler flue air system, and improve the thermal efficiency of the boiler, Moreover, it reduces the heat transfer pressure of the original rotary air preheater, completely solves the problems of cyanamide sulfate corrosion and blockage caused by denitrification, and reduces the energy consumption of the boiler to achieve maximum energy saving and emission reduction.

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