System for reducing discharge smoke temperature of power station boiler

Abstract

The invention relates to a system for reducing discharge smoke temperature of a power station boiler and belongs to the technical field of waste heat recovery, and the system is characterized that a heat transfer pipeline is arranged in the hot primary air pipeline of the boiler, the two ends of the heat transfer pipeline are respectively connected with a water inlet pipeline and a water outlet pipeline, the other ends of the water inlet pipeline and the water outlet pipeline are connected to a heater on the secondary air inlet air flue of an air pre-heater; and simultaneously a bypass flue is additionally arranged, thus the original smoke is divided into two paths, one path of the original smoke is sent into the air pre-heater through the original flue, and the other path of the originalsmoke is sent into a low-pressure high-temperature economizer through the bypass flue. The hot primary air is utilized to heat the cold secondary air, thereby improving the air temperature of a secondary air inlet; the primary air temperature is controlled by changing the quantity of a cooling medium in the heat transfer pipeline, thereby reducing the amount of the cold primary air doped in a coal pulverizing system; and a method of increasing the amount of the smoke in the bypass flue is adopted, thereby reducing the temperature of the discharge smoke. On the premise of ensuring the temperature of the secondary air, the surplus heat of the primary air is recycled, thus the coal consumption of the boiler and the heat rate of a steam turbine are reduced, and the economical efficiency of a power plant is improved.

Description

technical field [0001] The invention belongs to the technical field of waste heat recovery and utilization, and in particular relates to a system for reducing the exhaust gas temperature of a power plant boiler. Background technique [0002] At present, the energy saving and emission reduction of large thermal power units is one of the important national policies. The development of waste heat utilization technology for power station boilers will help reduce boiler coal consumption, improve unit operation economy, and reduce carbon dioxide, nitrogen oxides, sulfur oxides and other pollutants The discharge has important engineering practical value. The exhaust heat loss of power plant boilers is the largest among the various heat losses of boilers, generally about 5% to 12%, accounting for 60% to 70% of boiler heat losses. The main factor affecting the heat loss of the exhaust gas is the exhaust gas temperature, and the reasons for the increase of the exhaust gas temperature...

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Problems solved by technology

To achieve this without affecting the exhaust gas and secondary air temperature, and to ensure a reasonable air powder temperature at the outlet of the coal mill, it is impossible to solve the problem with the existing system and equipment

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