AIR-SURROUNDING-FUEL(ASF) PULVERIZED COAL BIAS COMBUSTION TECHNOLOGY WITH LOW Nox EMISSION

2002 ◽  
Vol 38 (01) ◽  
pp. 108 ◽  
Author(s):  
Shaohua Wu
Keyword(s):  
Pulverized Coal ◽  
Nox Emission ◽  
Combustion Technology ◽  
Low Nox Emission

Application Analysis on the Bias and Air Staged Combustion Technology in the Opposed Firing Boiler

2011 ◽  
Author(s):  
Tai-sheng Liu
Keyword(s):  
Recirculation Zone ◽  
Nox Reduction ◽  
Pulverized Coal ◽  
Nox Emission ◽  
Unburned Carbon ◽  
Staged Combustion ◽  
Bias Model ◽  
Combustion Technology ◽  
Radial Model ◽  
Low Nox Emission

The bias combustion technology has been widely used in the swirling burner. Take the distribution of the pulverized-coal concentration at the primary air outlet as the division principle, there are three kinds of bias combustion models: radial model with inside dense and outside lean, radial model with outside dense and inside lean, and circumferential model. Considering stable ignition and low NOx emission, at the phase of the pulverized-coal ignition, the dense pulverized-coal flow should be heated by the high temperature flue gas intensively and quickly to ensure the coal’s timely ignition and form an In-flame NOx reduction zone for low NOx emission. Hence the bias combustion technology should be in accordance with the recirculation zone. So the radial bias model with inside dense and outside lean suits to central recirculation zone while radial bias model with outside dense and inside lean suits to annular recirculation zone. The circumferential bias model suits to both recirculation zones. Furthermore, appropriate measures should be taken on the burner’s arrangement and furnace’s design to prevent the obvious increase of slagging problem and unburned carbon in fly ash when using bias and air staged combustion technology.

The combustion and NOx emission characteristics of the ultra-low volatile fuel using the novel pulverized coal self-sustained preheating combustion technology

Fuel ◽  
2020 ◽  
Vol 271 ◽  
pp. 117592 ◽  
Author(s):  
Wenhao Song ◽  
Ziqu Ouyang ◽  
Minghao Wang ◽  
Shiyuan Li ◽  
Jingzhang Liu ◽  
...  
Keyword(s):  
Pulverized Coal ◽  
Nox Emission ◽  
Emission Characteristics ◽  
The Novel ◽  
Combustion Technology

Environmental Protection and Fuel Consumption Reduction by Flameless Combustion Technology: A Review

2013 ◽  
Vol 388 ◽  
pp. 292-297 ◽  
Author(s):  
Seyed Ehsan Hosseini ◽  
Mazlan A. Wahid ◽  
Saber Salehirad
Keyword(s):  
Fuel Consumption ◽  
High Performance ◽  
High Efficiency ◽  
Combustion Process ◽  
The Other ◽  
Nox Emission ◽  
Flameless Combustion ◽  
Combustion Technology ◽  
Oil Crisis ◽  
Low Nox Emission

In recent years global fuel consumption has increased in the world due to modernization and progress in the standard of living. The conspicuous rate of carbon dioxide and nitrogen oxide released to the environment and fuel resources are depleted day by day due to inconsiderate fuel consumption. Requirement for efficient use of any kinds of fuel has become the other concern due to the oil crisis and limitation of fuel resources. In combustion process, the abatement of pollutants often associates with efficiency loss. In the other word, high efficiency and low pollutant which are the main requirements of combustion are not fulfilled by the existing combustion. Today, flameless combustion has received more attention because of its low NOx emission and significant energy saving. Generally, compatibility between high performance and low NOx emission has been observed by preheated air application and changing the combustion characteristics from traditional flame to flameless mode. This paper aims to review the concepts and the applications of flameless combustion and gathers useful information to understand the necessity of transient from traditional flame mode to flameless combustion.

The ultra-low NOx emission characteristics of pulverized coal combustion after high temperature preheating

Fuel ◽  
2020 ◽  
Vol 277 ◽  
pp. 118050 ◽  
Author(s):  
Yi Zhang ◽  
Jianguo Zhu ◽  
Qinggang Lyu ◽  
Jingzhang Liu ◽  
Fei Pan ◽  
...  
Keyword(s):  
High Temperature ◽  
Coal Combustion ◽  
Pulverized Coal ◽  
Nox Emission ◽  
Emission Characteristics ◽  
Pulverized Coal Combustion ◽  
Low Nox Emission

The mechanisms of flame stabilization and low NOx emission in an eccentric jet pulverized coal combustor

1992 ◽  
Vol 1 (4) ◽  
pp. 278-285
Author(s):  
Wenchao Sun ◽  
Yezhu Sun ◽  
Feng Qin ◽  
Chengkang Wu
Keyword(s):  
Flame Stabilization ◽  
Pulverized Coal ◽  
Nox Emission ◽  
Low Nox Emission

Effects of Over Fire Air on the Combustion and NOx Emission Characteristics of a 600 MW Opposed Swirling Fired Boiler

2012 ◽  
Vol 512-515 ◽  
pp. 2135-2142 ◽  
Author(s):  
Yu Peng Wu ◽  
Zhi Yong Wen ◽  
Yue Liang Shen ◽  
Qing Yan Fang ◽  
Cheng Zhang ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Empirical Method ◽  
Nox Emission ◽  
Emission Characteristics ◽  
Cfd Model ◽  
Nitrogen Release ◽  
Computational Fluid Dynamics Cfd ◽  
Low Nox Emission

A computational fluid dynamics (CFD) model of a 600 MW opposed swirling coal-fired utility boiler has been established. The chemical percolation devolatilization (CPD) model, instead of an empirical method, has been adapted to predict the nitrogen release during the devolatilization. The current CFD model has been validated by comparing the simulated results with the experimental data obtained from the boiler for case study. The validated CFD model is then applied to study the effects of ratio of over fire air (OFA) on the combustion and nitrogen oxides (NOx) emission characteristics. It is found that, with increasing the ratio of OFA, the carbon content in fly ash increases linearly, and the NOx emission reduces largely. The OFA ratio of 30% is optimal for both high burnout of pulverized coal and low NOx emission. The present study provides helpful information for understanding and optimizing the combustion of the studied boiler

Study of Medium-Btu Fueled Gas Turbine Combustion Technology for Reducing Both Fuel-NOx and Thermal-NOx Emissions in Oxygen-Blown IGCC

2002 ◽  
Author(s):  
Takeharu Hasegawa ◽  
Mikio Sato ◽  
Yasunari Katsuki ◽  
Tohru Hisamatsu
Keyword(s):  
Direct Injection ◽  
Combustion Method ◽  
Nox Emission ◽  
Two Stage ◽  
Gas Cleaning ◽  
Stage Combustion ◽  
Combustion Technology ◽  
Thermal Nox ◽  
Combustion Tests ◽  
Fuel Nox

In order to improve the thermal efficiency of the oxygen-blown IGCC (Integrated Gasification Combined Cycle) for stricter environmental standards and cost-effective option, it is necessary to adopt the hot/dry gas cleaning system. In this system, the flame temperature of medium-btu gasified fuel is higher and so NOx production from nitrogen fixation is expected to increase significantly. Also the gasified fuel contains fuel nitrogen, such as ammonia, in the case of employing the hot/dry gas cleaning system. This ammonia is easily oxidized into fuel-NOx in the combustor. For contribution to the protection of the environment and low cost operations of all kinds of oxygen-blown IGCC, low NOx combustion technology for reducing both the fuel-NOx and thermal-NOx emission has to be developed. In this paper, we clarified effectiveness of applying both the two-stage combustion and the nitrogen injection, and the useful engineering guidelines for the low-NOx combustor design of oxygen-blown gasified, medium-btu fuels. Main results obtained are as follows: (1) Based on the fundamental combustion tests using the small diffusion burner, we clarified that equivalence ratio at the primary combustion zone has to be adjusted due to the fuel conditions, such as methane concentration, CO/H2 molar ratio, and calorific values of gasified fuels in the case of the two-stage combustion method for reducing fuel-NOx emission. (2) From the combustion tests of the medium-btu fueled combustor the two-stage combustion with nitrogen direct injection into the combustor results in reduction of NOx emission to 80ppm (corrected at 16% O2) or less, the conversion rate of ammonia to NOx was 35% under the gas turbine operational conditions for IGCC in the case where fuel contains 3% of methane and 2135ppm of ammonia. By means of nitrogen direct injection, the thermal efficiency of the plant improved by approximately 0.3 percent (absolute), compared with a case where nitrogen is premixed with gasified fuel. The CO emission concentration decreased drastically, as low as 20ppm, or combustion efficiency was kept higher than 99.9%. Furthermore, based on the fundamental combustion tests’ results, the ammonia conversion rate is expected to decrease to 16% and NOx emission to 26ppm in the case of gasified fuel that contains 0.1% methane and 500ppm of ammonia. From the above results, it is clarified that two-stage combustion method with nitrogen injection is very effective for reducing both the fuel-NOx and thermal-NOx emissions at once in IGCC and it shows the bright prospects for low NOx and stable combustion technology of the medium-btu fuel.

Sign in / Sign up

Export Citation Format

Share Document