coal fired boilers pdf
(3) air preheater. Located in the coal fired boilers pdf backpass, whose role is to use waste heat of flue gas to heat the fuel required for the combustion air, exhaust gas temperature can be further reduced not only, but also for strengthening the furnace combustion, improve the economy of combustion, pulverized coal drying and conveying is advantageous of. Boiler efficiency can be increased by 2%. And rotary two kinds of charge.
Major effects of fuel on coal fired boilers pdf design
1.A wide range of coal properties can lead to over-sized pulverizing/firingequipmentwhich will in turn lead to a limitation on turn down and a possible increase in auxiliarypower consumption. This will also increase the furnace size and the SH and RH will need to be sized properly, which can be difficult at times, to get the rated outlet temperature.
2.Over-sizing of pulverize-rs and air heaters to handle occasionally high moisture coals will require excessive tempering air when handling normal moisture coals. Ultimately all these will result in higher gas outlet temperature, reducing the horizontal boiler efficiency.
3.The behavior of the ash during the combustion process and managing the coal-ash are the major issues in horizontal industrial boiler design. Deposition and slagging, heat transfer upsets, and fouling in convection passages are some of the major issues to be dealt during operation of the boiler.
Our case with 10-ton coal fired boilers pdf. Operating costs 10 tons of coal-fired boilers coal 600 yuan / ton, compared with 0.6 yuan / kg; calorific value 5500 kcal / kg; required heat 6 million kcal / hour and 10 ton boiler; coal boiler thermal efficiency 70-80 % (75% in accordance with our calculated): 10 tons of coal fired boiler 1 hour the desired amount: 6000000kcal / h ÷ 5500kcal ÷ 75% = 1455kg / h; 10 tons of coal boiler 1 hour investment costs: 1455 × 0.6 = about 873 yuan. 10 tons of gas boiler running costs of piped natural gas price of about 2.8 yuan / Nm3; calorific value of 8600 kcal / Nm3; thermal efficiency between 90% -95% (we calculated 90%); caloric needs 6 million is 10 ton boiler cards / hour, i.e. 77.52Nm3 / h; 10 tons of gas required for the gas boiler 1 hour: 6000000kcal / h ÷ 8600kcal ÷ 90% = 775.2Nm3 / h; 10 tons of gas boiler 1 hour run investment costs: 2.8 yuan / Nm3 × 775Nm3 / h = 2170 dollars.
Recently, Taiyuan, Shanxi Province Environmental Protection Leading Group issued a circular on promoting the transformation of ultra-low emissions and low nitrogen transformation of biomass coal fired boilers pdfs gas-fired boiler. Resolutely implement - the latest requirements "2018 in Beijing, Tianjin and the surrounding areas in 2019 autumn and winter tackling air pollution comprehensive management action plan" in, and further reduces boiler emissions standards.
1, 2019 until October 31, the use of boiler tail decoration efficient dust removal, desulfurization, stock device is accomplished ultra-low emission biomass boilers transformation of the necessary funds by the counties (cities, districts) and users together to solve, not the municipal finance I grant.
2, October 31, 2019 update for ultra-low emissions of nitrogen gas boilers, electric boilers biomass boilers, municipal finance one-time grant 30 yuan / square meter construction costs, in part by the lack of counties (cities, districts) and user common solutions.
Way: by transformation to replace the low NOx combustion, a flue gas recirculation device installation mode, NOx emission is less than 30 mg / m item.
NOx emission cuts ≥50%, and the concentration value of less than 30 mg / cubic meter project, to give up prize money of 30% in accordance with the transformation of investment.
3, after December 31, 2017 the new gas boiler, should meet the emission requirements on Taiyuan low NOx combustion, but does not enjoy the low NOx combustion subsidies.