| Haze weather occurred frequently in recent years and local policy enacted against coal-fired boiler, make people have great prejudice on coal-fired industrial boilers. At present, our country in about 0.6 million units in industrial boiler, fuel consumption of about 700 million tons of standard coal, accounts for about one 5 of the total coal production in our country, and there exists such problems as low efficiency, severe pollutant emission. Industrial boiler pollutant total amount each year is about: 1.6 million tons of dust, SO2718 ten thousand tons, 2.71 million tons of NO_x. As one of the important pollutants, including NO_x both selective catalytic reduction(SCR) and selective catalytic reduction(SNCR), industrial boiler structure and load fluctuation are unable to meet the needs of the process. In such a background, the application in industrial boilers pulverized coal efficient clean combustion technology, can effectively solve the above problems. This topic is based on the cooperation unit of a ma YLW- 7000 type organic heat medium boiler,chain furnace in the boiler with independent research and development of high efficiency low NO_x liquid slag pulverized coal burner, and built a set of pulverized coal industry boiler system that could satisfy the requirement of enterprise production.1. Open type pulverized coal preparation system: first, to the traditional grinding drying system and system integration, optimization, and then through the technology import and export temperature dryer, air leakage rate is calculated, the raw coal moisture,balance duct air volume of the system, the influence of the thought appropriate for enhancing the inlet temperature, reduce the air leakage rate, and balance the dryer duct air volume, strengthening the drying efficiency of the dryer oxygen content of raw coal consumption of hot air stove, and system load, induced draft fan is good; The raw coal moisture to dry the high oxygen content of the system, more should pay attention to;According to the hidden trouble in security system, targeted for protection and monitoring measures.2. Venturi feeder: according to the requirement of the system for powder venturi feeder is calculated by the theory of the theory of parameter. The no-load and load experiments to measure the venturi nozzle inlet pressure, receiving chamber pressure and the parameters of the powder pipeline back pressure change, get the nozzle size, thethrottling ratio, nozzle distance to accept chamber and lose powder for powder to the stability of the pipe flow. Results show that the transmission speed, same Φ 60 mm powder pipeline condition, the back pressure significantly decreased; Φ 17 mm nozzle is helpful to improve the negative pressure of nozzle flow rate in order to improve the reception room;Throttle than 0.34 help powder pipeline in the cross section of uniform speed and reduce the negative pressure of the pipe resistance and improve reception room; Nozzle distance to accept the room take 40 mm lose powder is relatively stable; Powder pipeline flow cannot be less than 25 m/s, can appear otherwise pulverized coal subsidence phenomenon.3. The performance of high efficiency low NO_x pulverized coal industry boiler: first of all to the organic heat medium high efficiency low NO_x pulverized coal furnace, to carry out the excess air coefficient, burning wind rate, burner way of air distribution, load of hot state experimental research, the results show that excess air coefficient is about 1.1 a certain control of NO_x emissions and can ensure efficiency; Burning wind rate of NO_x generation, liquid slag discharge amount and combustion efficiency, according to the different load adjustment for burning rate of the wind. Finally, the modified organic heat carrier according to pulverized coal furnace according to test standard for energy efficiency and environmental protection, boiler thermal efficiency is within the scope of 60% ~ 100%can reach more than 90%; In the case of without denitration equipment, implements the NO_x emissions below 150 mg/m after, fully meet the boiler air pollutant emission standard"(GB 13271-2014) emissions limits in the key areas.4. High efficiency low NO_x pulverized coal industry boiler performance: first of all,in organic heat medium high efficiency low NO_x pulverized coal furnace on excess air coefficient, burning wind rate, hot burner way of air distribution, load test and research.Results show that the excess air coefficient is about 1.1 a certain control of NO_x emissions and can guarantee the combustion efficiency; Burning wind rate of NO_x generation, liquid slag discharge amount and combustion efficiency, according to the different load adjustment for burning wind rate; Burner three times the wind rate of slag film formation location and NO_x generation has a direct relationship. Then under the condition of low NO_x emission test for energy efficiency and environmental protection, boiler thermal efficiency is about 90% within the range 60% ~ 100%; In the case of without denitration equipment, NO_x realized below 150 mg/m after discharge, are comparable to those obtained with gas furnace. |
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