scholarly journals RECONSTRUCTION OF GAS DUCTS OF WATER BOILERS WITH INSTALLATION OF FLUE GAS PUMPS

2021 ◽  
Vol 10 (4) ◽  
pp. 42-49
Author(s):  
Svetlana A. MINKINA ◽  
Maxim I. URYADOV
Keyword(s):  
Flue Gas ◽  
Combustion Products ◽  
Hot Water ◽  
Thermal Calculation ◽  
Parallel Operation ◽  
Load Range ◽  
Full Capacity ◽  
Regime Map

The work is devoted to solving the problem of the lack of draft of the existing chimney when operating hot water boilers at full capacity. Thermal and aerodynamic calculations were performed. Thermal calculation was carried out with diff erent loading of hot water boilers and the number of operating burners. The options for the operation of boilers according to the regime map and test protocols are considered. In the aerodynamic calculation for the sections, the resistance of the gas ducts was determined, the chimney was calculated. A fl ue gas pump is installed to remove combustion products from hot water boilers. This will ensure the parallel operation of two hot water boilers over the entire load range.

scholarly journals Reliable simple zonal method of the furnace thermal calculation

2005 ◽  
Vol 9 (2) ◽  
pp. 45-55
Author(s):  
Vladan Ivanovic
Keyword(s):  
Energy Consumption ◽  
Flue Gas ◽  
Thermal Load ◽  
Operating Conditions ◽  
Thermal Calculation ◽  
Gas Temperature ◽  
Zonal Method ◽  
One Dimensional ◽  
Furnace Performance ◽  
Steam Boilers

The calculation of the furnace in the industrial and power boilers is the most important and the most responsible part of the thermal calculation, and it has important influence on the rationalization of energy consumption. In the paper one-dimensional zonal method of the furnace thermal calculation of steam boilers is presented. It can successfully define disposition of flue gas temperature and specific thermal load of screen walls with height of the furnace in case of uneven deposits distribution which vary in size and quality. Its greatest use is for comparing furnace performance under various operating conditions.

scholarly journals Energy-saving biomass stove

2014 ◽  
Vol 6 (2) ◽  
pp. 115-119
Author(s):  
Tri Hoang
Keyword(s):  
Energy Saving ◽  
Rice Husk ◽  
Flue Gas ◽  
Particle Concentration ◽  
Combustion Process ◽  
Combustion Products ◽  
Raw Material ◽  
Gas Emission ◽  
Biomass Stove ◽  
Residual Oxygen

This paper introduces an energy-saving biomass stove. The principle of energy-saving biomass stove is gasification. It is a chemical process, transforms solid fuel into a gas mixture, called (CO + H2 + CH4) gas. Emission lines in the stove chimneys typically remain high temperatures around 90° to 120°C. The composition of the flue gas consists of combustion products of rice husk which are mainly CO2, CO, N2. A little volatile in the rice husk, which could not burn completely, residual oxygen and dust will fly in airflow. The amount of dust in the outlet gas is a combination of un-burnt amount of impurity and firewood, usually occupied impurity rate of 1 % by weight of dry husk. Outlet dust of rice husk furnace has a normal size from 500μm to 0.1 micron and a particle concentration ranges from 200-500 mg/m3. Gas emissions is created when using energy-saving stove and they will be used as the main raw material in combustion process Therefore the CO2 emission into the environment when using the stove will be reduced up to 95% of a commonly used stove. Bài báo giới thiệu một bếp tiết kiệm dùng năng lượng sinh khối. Bếp tiết kiệm năng lượng thực hiện nguyên lý khí hóa sinh khối. Đó là một quá trình hóa học, chuyển hóa các loại nhiên liệu dạng rắn thành một dạng hỗn hợp khí đốt, gọi là khí Gas (CO + H2 + CH4). Dòng khí thải ra ở ống khói của bếp thông thường có nhiệt độ vẫn còn cao khoảng 90° ~ 120°C. Thành phần của khói thải bao gồm các sản phẩm cháy của trấu, chủ yếu là các khí CO2, CO, N2, một ít các chất bốc trong trấu không kịp cháy hết, oxy dư và tro bụi bay theo dòng khí. Lượng bụi tro có trong khói thải chính là một phần của lượng không cháy hết và lượng tạp chất không cháy có trong củi, lượng tạp chất này thường chiếm tỷ lệ 1% trọng lượng trấu khô. Bụi trong khói thải lò đốt trấu thông thường có kích thước hạt từ 500μm tới 0,1μm, nồng độ dao động trong khoảng từ 200-500 mg/m3. Lượng khí thải được sinh ra khi sử dụng bếp tiết kiệm năng lượng, sẽ được dùng làm nguyên liệu đốt cháy chính của quá trình đó. Do đó lượng khí CO2 thải ra môi trường khi sử dụng bếp tiết kiệm sẽ được giảm xuống 95 % so với sử dụng bếp thường.

scholarly journals Combined NOx and NH3 Slip Reduction in a Stoker Boiler Equipped with the Hybrid SNCR + SCR System FJBS+

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8599
Author(s):  
Robert Wejkowski ◽  
Sylwester Kalisz ◽  
Przemysław Garbacz ◽  
Izabella Maj
Keyword(s):  
Fly Ash ◽  
Flue Gas ◽  
Full Range ◽  
Nox Reduction ◽  
Main Idea ◽  
Cost Effective ◽  
Combustion Products ◽  
Ammonia Removal ◽  
Ammonia Content ◽  
Ammonia Slip

The application of secondary NOx control methods in medium to low-capacity furnaces is a relatively new topic on the energy market and thus requires further research. In this paper, the results of full-scale research of SNCR and hybrid SNCR + SCR methods applied into a 29 MWth solid fuel fired stoker boiler is presented. The tests were performed for a full range of boiler loads, from 33% (12 MWth) to 103% (30 MWth) of nominal load. A novel SNCR + SCR hybrid process was demonstrated based on an enhanced in-furnace SNCR installation coupled with TiO2-WO3-V2O5 catalyst, which provides extra NOx reduction and works as an excess NH3 “catcher” as well. The performance of a brand-new catalyst was evaluated in comparison to a recovered one. The emission of NOx was reduced below 180 mg NOx/Nm3 at 6% O2, with ammonia slip in flue gas below 10 mg/Nm3. Special attention was paid to the analysis of ammonia slip in combustion products: flue gas and fly ash. An innovative and cost-effective method of ammonia removal from fly ash was presented and tested. The main idea of this method is fly ash recirculation onto the grate. As a result, ammonia content in fly ash was reduced to a level below 6.1 mg/kg.

Gasified boiler units

2021 ◽  
Author(s):  
Vyacheslav Kuznecov ◽  
Oleg Bryuhanov
Keyword(s):  
Vocational Education ◽  
Thermal Control ◽  
Combustion Products ◽  
Hot Water ◽  
Automatic Regulation ◽  
Federal State ◽  
Auxiliary Equipment ◽  
Secondary Vocational Education ◽  
Supply Systems ◽  
Gas Supply

The textbook gives the basic concepts of gasified heat generating (boiler) installations and the terminology used in boiler technology, the principle of operation and device of gasified heat generating (boiler) installations. The types and device of heat generators (boilers) of their furnace devices are considered; types and device of gas-burning devices, the number and places of their installation in furnace devices; auxiliary equipment-devices for air supply and removal of combustion products, devices for water treatment, steam supply and circulation of the coolant of hot water boilers; device for thermal control and automatic regulation of the boiler installation. The issues of operation and efficiency of gasified heat generating (boiler) installations and their gas supply systems; requirements for conducting gas-hazardous and emergency recovery operations of gas supply systems are considered. Meets the requirements of the federal state educational standards of secondary vocational education of the latest generation. For students of secondary vocational education in the specialty 08.02.08 "Installation and operation of equipment and gas supply systems".

Lean Blowout Limit and NOx Production of a Premixed Sub-ppm NOx Burner With Periodic Recirculation of Combustion Products

2004 ◽  
Vol 128 (2) ◽  
pp. 247-254 ◽  
Author(s):  
Jochen R. Kalb ◽  
Thomas Sattelmayer
Keyword(s):  
Natural Gas ◽  
Flue Gas ◽  
Combustion Products ◽  
Gas Content ◽  
Stable Operation ◽  
Reacting Flow ◽  
Nox Emissions ◽  
Current Standard ◽  
Lean Blowout ◽  
Fresh Mixture

The technological objective of this work is the development of a lean-premixed burner for natural gas. Sub-ppm NOx emissions can be accomplished by shifting the lean blowout limit (LBO) to slightly lower adiabatic flame temperatures than the LBO of current standard burners. This can be achieved with a novel burner concept utilizing spatially periodic recirculation of combustion products: Hot combustion products are admixed to the injected premixed fresh mixture with a mass flow rate of comparable magnitude, in order to achieve self-ignition. The subsequent combustion of the diluted mixture again delivers products. A fraction of these combustion products is then admixed to the next stream of fresh mixture. This process pattern is to be continued in a cyclically closed topology, in order to achieve stable combustion of, for example, natural gas in a temperature regime of very low NOx production. The principal ignition behavior and NOx production characteristics of one sequence of the periodic process was modeled by an idealized adiabatic system with instantaneous admixture of partially or completely burnt combustion products to one stream of fresh reactants. With the CHEMKIN-II package, a reactor network consisting of one perfectly stirred reactor (PSR, providing ignition in the first place) and two plug flow reactors (PFR) has been used. The effect of varying burnout and the influence of the fraction of admixed flue gas has been evaluated. The simulations have been conducted with the reaction mechanism of Miller and Bowman and the GRI-Mech 3.0 mechanism. The results show that the high radical content of partially combusted products leads to a massive decrease of the time required for the formation of the radical pool. As a consequence, self-ignition times of 1 ms are achieved even at adiabatic flame temperatures of 1600 K and less, if the flue gas content is about 50–60% of the reacting flow after mixing is complete. Interestingly, the effect of radicals on ignition is strong, outweighs the temperature deficiency and thus allows stable operation at very low NOx emissions.

Analysis on the Calculation Methods of Acid Dew Point of Flue Gas

2014 ◽  
Vol 960-961 ◽  
pp. 414-421
Author(s):  
Chen Zong ◽  
Xiao Hui Zhang ◽  
Qi Min Wang
Keyword(s):  
Soviet Union ◽  
Flue Gas ◽  
Former Soviet Union ◽  
Bituminous Coal ◽  
Dew Point ◽  
Thermal Calculation ◽  
Calculation Methods ◽  
Typical Instance ◽  
New Formula

At present, there are lots of calculation methods of acid dew point of flue gas; formula of acid dew point in the thermal calculation from the former U.S.S.R has been widely applied in China. But this formula still has some problems, such as the desulphurization ability of different fuels, classification of sulfur content in fuel and the factors of SO2 transferred into SO3.In order to solve these problems,the formula of the acid dew point in the thermal calculation from the former U.S.S.R is adjusted. It was found that the precision of A.G.O kkes formula is the highest by comparing several formulas. So the last will be the compilation of the new formula and A.G.O kkes formula, the former Soviet union formula and the calculation of burning lean coal,bituminous coal and lignite typical instance of 600 MW,it was found that the precision of new formula calculation has improved.

Preliminary Calculations on Post Combustion Carbon Capture From Gas Turbines With Flue Gas Recycle

2013 ◽  
Author(s):  
Muhammad Akram ◽  
Bhupendra Khandelwal ◽  
Simon Blakey ◽  
Christopher W. Wilson
Keyword(s):  
Gas Turbine ◽  
Flue Gas ◽  
Gas Turbines ◽  
Carbon Capture ◽  
Hot Water ◽  
Low Carbon ◽  
Air Inlet ◽  
Carbon Combustion ◽  
Set Up ◽  
The University

Carbon capture is getting increased attention recently due to the fact that it seems to be the only answer to decrease emissions. Gas turbines exhaust have 3–5 % concentration of CO2 which is very low to be captured by an amine carbon capture plant effectively. The amine based plants are most effective at around 10 – 15% CO2 in the flue gas. In order to increase the concentration of CO2 in the exhaust of the gas turbine, part of the exhaust gas needs to be recycled back to the air inlet. On reaching the concentration of CO2 around 10% it can be fed to the amine capture plant for effective carbon capture. A 100 kWe (plus 150 kW hot water) CHP gas turbine Turbec T100 is installed at the Low Carbon Combustion Centre of the University of Sheffield. The turbine set up will be modified to make it CO2 capture ready. The exhaust gases obtained will be piped to amine capture plant for testing capture efficiency. Preliminary calculations have been done and presented in this paper. The thermodynamic properties of CO2 are different from nitrogen and will have an effect on compressor, combustor and turbine performance. Preliminary calculations of recycle ratios and other performance based parameters have been presented in this paper. This paper also covers the aspects of turbine set up machinery which needs to be modified and what kind of modifications may be needed.

Design Optimization of Convective Heat Transfer Surface of Pressurized Oxy-Fuel Coal-Fired Boiler

2012 ◽  
Vol 614-615 ◽  
pp. 20-24
Author(s):  
Kai Ma ◽  
Wei Ping Yan ◽  
Fei Jin ◽  
Hai Xin Li
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Flue Gas ◽  
Convective Heat Transfer Coefficient ◽  
Heating Surface ◽  
Fuel Combustion ◽  
Thermal Calculation ◽  
Heat Output ◽  
Atmospheric Air

Based on the thermal calculation, the paper makes a contrastive analysis on the parameters of flue gas, and convection heat properties of the coal-fired boiler under atmospheric air combustion, atmospheric oxy-fuel combustion and pressurized (6MPa) oxy-fuel combustion conditions. It takes a 300MW pressurized(6MPa) oxy-fuel combustion boiler as research object, the result indicates that: compared to the coal-fired boiler atmospheric air combustion, the flue gas volume flow in the pressurized oxy-fuel combustion has a decrease of 98.79%; convective heat output has a decrease of 24.69% with the same difference in temperature. In the pressurized oxy-fuel combustion, both the flue gas convective heat transfer coefficient and the pressure drop are greater than the atmospheric oxy-fuel combustion, flue cross-sectional area is smaller than conventional boiler, and heating surface area is less than atmospheric oxy-fuel combustion. With a method named dynamic minimization of costs the best flue gas velocity in this paper is 1.07m/s

scholarly journals Use of condensing economizers with developed surfaces to improve the energy efficiency of conventional gas-fired heat generators in boilers

2021 ◽  
Vol 263 ◽  
pp. 04024
Author(s):  
Dmitriy Kosorukov ◽  
Andrey Aksenov
Keyword(s):  
Energy Efficiency ◽  
Local Heating ◽  
Combustion Products ◽  
Hot Water ◽  
Dew Point ◽  
Efficient Design ◽  
Cold Surface ◽  
Boiler Plant ◽  
Temperature Combustion ◽  
The Russian Federation

The current financial and economic programme in the Russian Federation is aimed at increasing energy efficiency in all areas of society. The most effective way of increasing the efficiency of boiler plant operation is to improve the technology of deep heat recovery from the heated flue gas from the chimney system of hot-water boilers. The physical essence of this phenomenon consists in cooling the escaping high-temperature combustion products of gaseous fuel, through contact with the cold surface of the heat exchanger, to a temperature below the dew point under the pressure in the convective bundle of the boiler. In this regard, we set a goal to develop the most efficient design of condensing economizer, which would allow us to obtain fuel economy of gas boiler at the level of operation of condensing heat generators. A practical model of a condensing economizer for increasing the efficiency of heat generators based on convection-type gas boilers has been created. A study has been carried out, the results of which allow us to conclude on the effectiveness of its use for individual and local heating of residential and public buildings.

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