High efficiency catalytic denitration device with function of phase change temperature control

Abstract

The invention relates to a high efficiency catalytic denitration device with a function of phase change temperature control. The device comprises a catalytic denitration reactor; a rectifying unit isarranged at the upper part of the catalytic denitration reactor; a diversion unit is arranged at the upper part of the rectifying unit; a plurality of honeycomb catalyst bed layers are arranged in thecatalytic denitration reactor, positioned at the lower part of the rectifying unit, in parallel; an ammonia water grille is arranged at the front end of an inlet flue; cavities of the diversion unitand the rectifying unit are respectively and internally filled with a first type of solid-liquid phase change heat storage material and a second type of solid-liquid phase change heat storage material; a solid-solid phase change thermal storage insulation layer is attached at the periphery of a flue gas pipeline of the catalytic denitration reactor between the ammonia water grille and the catalystbed layers. The high efficiency catalytic denitration device can effectively solve the problems of large fluctuation of smoke temperature and low catalytic efficiency in the denitration reactor of acoal-fired power plant, is large in temperature adjustment range and good in the temperature control effect, and can improve the removal efficiency of nitrogen oxides.

Description

technical field [0001] The invention relates to a phase change temperature control denitrification device, in particular to a phase change temperature control high-efficiency catalytic denitrification device. Background technique [0002] At present, selective catalytic reduction flue gas denitrification technology has become the mainstream technology for denitrification equipment in thermal power plants. The variable load operation of power plant boilers and frequent peak regulation of power grids lead to large fluctuations in flue gas temperature, and it is impossible to ensure that the denitrification catalyst is in the best condition. Participate in catalytic reactions in the active temperature range, resulting in a significant reduction in catalytic efficiency or even inactivation. At the same time, due to the decrease in temperature, the solubility of the ammonium salt is also reduced and agglomerated, blocking the honeycomb catalyst framework, increasing the flow resi...

AI Technical Summary

Problems solved by technology

At the same time, an economizer bypass is also installed to increase the flue gas temperature at the inlet of the SCR denitrification system, which is used to increase the catalytic temperature under low load conditions, but the problem is that part of the flue gas not passing through the economizer will inevitably lead to boiler efficiency. The mixture of economizer bypass flue gas and main flue gas will also cause uneven flow field inside the flue and denitrification device, and increase the pressure loss

In addition, when the temperature of the flue gas flowing through the reactor is low, the catalyst activity decreases, and the reductant ammonia and SO in the flue gas 3 The reaction produces ammonium bisulfate and ammonium sulfate, which will be deposited on the catalyst, further reducing the activity of the catalyst, and even causing an irreversible reduction in the activity of the catalyst.

[0003] Chinese patent CN203829919U proposes a device for the SCR boiler denitrification system of a coal-fired power plant boiler. Although the temperature of the catalytic reaction can be adjusted to a certain extent, this method attaches a solid-liquid phase change material around the honeycomb catalyst. On the one hand It takes time for phase change materials to melt and solidify. This arrangement cannot fully release the latent heat of phase change, resulting in the flue gas temperature not reaching the ideal catalytic temperature, and the catalytic efficiency is low.

On the other hand, phase change materials will inevitably occupy the space for flue gas circulation, reducing the amount of flue gas flowing through, increasing the flow resistance of flue gas, and possibly changing the working environment of subsequent devices.

In addition, the narrow space around the catalyst bed is filled with phase change materials, which is not enough to meet the large heat capacity requirements for adjusting the internal temperature of the denitrification device when the large unit is running at low load.

Images