Device for reducing cold air doping rate of hot primary air

Abstract

The invention relates to a device for reducing the cold air doping rate of hot primary air. The device comprises a blower, an air preheating device and a combustor, wherein the blower, the air preheating device and the combustor are sequentially connected in the air inlet direction. The air preheating device is connected with the combustor through a primary air pipe. The device for reducing the cold air doping rate of the hot primary air is characterized in that a bypass air channel is arranged, the initial end and the tail end of the bypass air channel are connected to different positions of the primary air pipe, the flow direction of the inner air of the bypass air channel is identical with the flow direction of the inner air of the primary air pipe and an inlet closing baffle, a hot primary air cooler, an outlet closing baffle, a pressurizing fan and an air channel compensator are sequentially arranged on the bypass air channel in the air inlet direction. A regulating baffle and a first closing baffle are sequentially arranged on the part, located between the initial end and the tail end of the bypass air channel, of the primary air pipe in the air inlet direction. A pulverized coal feeding machine is arranged behind the tail end, located on the bypass air channel, on the primary air pipe in a connected mode. The device for reducing the cold air doping rate of the hot primary air has the advantages of being simple in structure, convenient to use, low in cost of coal in generating electricity and capable of improving the efficiency of a boiler and saving the operation cost.

Description

technical field [0001] The invention belongs to boiler equipment, and relates to a device for reducing the mixing rate of hot primary air and cold air. Background technique [0002] An important reason for the high exhaust gas temperature of power plant units is that the pulverizing system is mixed with cold air. According to the analysis of operation data, the mixing rate of cold air in the pulverizing system is not less than 25%. This point causes the exhaust gas temperature to rise by 8°C to 10°C. Limited by the minimum wind speed of the powder pipe, the desiccant recirculation door can no longer be opened (the air pressure at the outlet is maintained at about 4.2kpa). According to the above situation, it is decided to adopt hot primary air cooling technology to reduce the mixing rate of cold air in the milling system to close to zero, so as to reduce the loss of exhaust smoke and improve the efficiency of the unit. [0003] 1. Current status of boiler units [0004] ...

AI Technical Summary

Problems solved by technology

[0008] 2.3 The effect is not good after the boiler has undergone low-nitrogen modification of the burner

Cause boiler efficiency deviation of 1.0 to 1.5 percentage points

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