Control method for solving thermal power plant coal-fired boiler Nox signal upside-down hanging

Abstract

According to the problem that flue gas NOx signals of denitration control systems generally exist in boilers of some thermal power plants in China at present, a control method of the present inventionutilizes installation equipment and DCS control systems of existing boiler denitration control systems according to the flowing characteristic of flue gas serving as fluid and the working principle of measurement and installation of thermal instrument sensors; under the condition that equipment and investment are not increased, related data of a DCS control system are comprehensively analyzed andreasonably distributed to adjust the ammonia spraying amount of each nozzle, so that the problem that a clean flue gas Nox signal of a coal-fired boiler of a thermal power plant is larger than a desulfurization inlet flue gas Nox signal, and the desulfurization inlet flue gas Nox signal is larger than an outlet Nox signal of a denitration device is solved. According to the invention, the automatic control level of the denitration system is improved, and the ammonia spraying amount at the outlet of the denitration device matched with the load is controlled as much as possible in different stages of the load, so that the purposes of energy conservation and environmental protection are achieved, and more solution benefits are created for enterprises.

Description

[0001] 1. Technical field [0002] The patent of the invention relates to a control method for solving Nox signal inversion of a coal-fired boiler in a thermal power plant, and is especially suitable for a large-scale coal-fired boiler in a thermal power plant that uses multiple nozzles for the SCR denitrification device. [0003] 2. Background technology [0004] At present, with the further improvement of the country's requirements for energy saving and emission reduction, coal-fired units in large-scale thermal power plants must be installed with denitrification devices. In a rectangular flat flue between the outlet and the air preheater inlet baffle, a reactor containing a catalyst is installed inside, and the NOx measurement device at the denitrification outlet is installed on the horizontal flue behind the air preheater inlet baffle, and the desulfurization inlet flue gas NOx The measurement device is installed on the horizontal flue after the outlets of the two induced d...

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Problems solved by technology

[0009] In order to overcome the shortcomings of the background technology, the patent of the present invention provides a control method for solving the NOx signal inversion of the coal-fired boiler in the thermal power plant. The flue gas Nox signal, the flue gas Nox signal at the desulfurization inlet is greater than the NOx at the denitrification outlet, so as to facilitate the automatic adjustment and control of the denitrification system to meet environmental protection requirements and avoid the assessment of excessive NOx emissions

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