Analysis of the Characteristics of Low NOx Combustion Using Exhaust Gas Recirculation

2014 ◽  
Vol 700 ◽  
pp. 220-224
Author(s):  
Yan Liu ◽  
Feng Li Kang ◽  
Rong Liu ◽  
Chi Jia Li ◽  
Qing Yu Wang
Keyword(s):  
Combustion Process ◽  
The United States ◽  
Air Pollutant ◽  
National Bureau ◽  
Nox Emissions ◽  
Health It ◽  
Combustion Phase ◽  
Low Nox Combustion ◽  
Nitric Oxide Emissions ◽  
Gas Recirculation

NOx damages to the environment. It also endangers human body health. It has become a major air pollutant. Only the nitric oxide emissions could be reduced by the improvement of combustion. The economical and reasonable technical measures, which is through selecting rational parameters and combustion process, could decrease the formation of NOx in fuel combustion phase. According to the national bureau of statistics data released, the national NOx emissions will reach 29.14 million ~ 42.96 million t in 2030,what is more ,China will surpass the United States to be the world's largest NOx emissions country. Environmental pollution has become one of the main factors restricting the development of economy in China [1].

On the Influence of Fuel Mixing and Flue Gas Recirculation on the Emissions of a Fuel Flexible Gas Turbine Combustor

2015 ◽  
Author(s):  
Stefan Fischer ◽  
David Kluß ◽  
Franz Joos
Keyword(s):  
Nitric Oxide ◽  
Flue Gas ◽  
Nox Emissions ◽  
Combined Effects ◽  
Fuel Gas ◽  
Flue Gas Recirculation ◽  
Mixing Behavior ◽  
Nitric Oxide Emissions ◽  
Fuel Mixing ◽  
Gas Recirculation

The main benefits of operating a combustor under flue gas recirculation conditions are the increase in efficiency of the post combustion carbon capture and storage process and the potential to reduce NOX emissions while keeping the thermal load of the gas turbine constant. The latter is primarily caused by the change in thermodynamic properties of the combustive mixture with increasing vitiation. As a result, the dominant NOX formation pathways change with increasing FGR ratio. In a partially premixed combustor, the formation of NOX emissions can also be influenced by the fuel mixing behavior. Different setups lead to combustive mixtures with different degrees of homogeneity as well as influencing the distribution of the mixture within the combustion chamber. In this paper the combined effects of the variation of mixture homogeneity and the flue gas recirculation ratio on the NOX emissions and the stability range is experimentally investigated for different fuel gases. The experiments are performed on the atmospheric laboratory test rig, which is equipped with a partially premixed combustor. The burner is equipped with modular fuel gas nozzles allowing for the variation of the fuel mixing behavior. Exhaust gas measurements are performed to evaluate the influence of the parameters on the emissions profile of the combustor and to compare the results to a theoretical study. The results of this study show that the level of nitric oxide emissions as well as the potential to decrease said emissions with FGR operation is dependent on the mixing behavior of the combustor. Furthermore, the combined effects of fuel gas nozzle and FGR operation lead to a proposal of an operational strategy for the combustor which combines the advantages of low nitric oxide emissions and a broad range of stability.

Premixing Gas and Air to Reduce NOx Emissions With Existing Proven Gas Turbine Combustion Chambers

1986 ◽  
Author(s):  
B. Becker ◽  
P. Berenbrink ◽  
H. Brandner
Keyword(s):  
Gas Turbine ◽  
Nox Reduction ◽  
Combustion Process ◽  
Liquid Fuels ◽  
Nox Emissions ◽  
Combustion Chambers ◽  
Load Range ◽  
Usual Manner ◽  
Low Nox Combustion ◽  
Gas Turbine Combustion

In the case of the burners employed in KWU gas turbine combustion chambers, the entire primary air is supplied through the swirlers associated with the burners. It is thus relatively easy to add natural gas to this air uniformly before it enters the combustion zone. This results in a particularly low NOx combustion process provided that the air to fuel ratio is being maintained within a certain range. The supplementary equipment to premix the fuel and air does not affect the burner performance when the fuel is supplied in the conventional way by means of gas or oil nozzles. Consequently, the gas turbine will be started up and loaded in the usual manner. In the high load range the burners are then switched over to premixed combustion operation. A small amount of fuel through the central gas nozzle stabilizes the flame in the case of a sudden load decrease. Combustion chambers already in service can be retrofitted with the new premixing equipment to reduce NOx emissions to about one third of the original values. The combustors can be operated with liquid fuels together with steam or water for NOx reduction in the conventional way.

Characteristics Study of Knocking, Fuel Consumption and Emissions with Cooled External EGR on SIDI Turbo Charged Gasoline Engine

2011 ◽  
Vol 66-68 ◽  
pp. 102-107
Author(s):  
Ying Li Zu ◽  
Zheng Xin Zhou ◽  
Hong Yang Yu
Keyword(s):  
Fuel Consumption ◽  
Gasoline Engine ◽  
Direct Injection ◽  
Combustion Process ◽  
Spark Timing ◽  
Study Results ◽  
Combustion Phase ◽  
Variable Valve ◽  
Gas Recirculation ◽  
Fuel Consumption And Emissions

Based on 2.0L spark ignition direct-injection(SIDI) turbo charged gasoline engine with variable valve timing(VVT), the spark timing effects on combustion process, fuel consumption, knock limitation and emissions were studied with external exhaust gas recirculation(EGR) on different loads and speeds. For the purpose of easily comparing data results, the location of 50% mass fraction burned(CA50) was widely used in this paper. The study results show that CA50 is changing linearly with spark timing. To reach the same combustion phase, spark timing need to be further advanced with external EGR. Combustion variability of IMEP(COV) increase sharply with retarding of CA50 with external EGR. The external EGR can greatly improve knock limitation and knock intensity(KI). To reach the best fuel consumption, CA50 need to be advanced to 6 °CA to 8 °CA for both with external EGR and without external EGR. NOx emissions increase with advancing of spark timing. HC show different trends when retarding spark timing with and without external EGR.

An Experimental Study on the Effects of Intake Charge and Pilot Injection on Premixed Burn Fraction and NOx Emission Characteristics of a CRDI Turbocharged Diesel Engine

2019 ◽  
Author(s):  
Nivin Chacko ◽  
Thangaraja Jeyaseelan ◽  
Vijay Anirudh Premnath
Keyword(s):  
Experimental Study ◽  
Diesel Engine ◽  
Combustion Process ◽  
Premixed Combustion ◽  
Nox Emission ◽  
Pilot Injection ◽  
Turbocharged Diesel Engine ◽  
Combustion Phase ◽  
Pilot Fuel ◽  
Gas Recirculation

Abstract The engine-out NOx emission from the combustion process depends on the fraction of premixed fuel burned. Hence, the study of the premixed combustion phase provides the flexibility to understand the NOx and other emissions. Here we performed an experimental study by modifying the intake charge along with pilot fueling on a twin-cylinder turbocharged CRDi diesel engine. The operating parameters, exhaust gas recirculation (EGR) and pilot injection were controlled to study about the premixed combustion phase, which gives minimum NOx emission without compromising other emissions particularly smoke. The results indicate that the premixed burn fraction decreased with an increase in pilot fuel quantity, dwell period and increased with higher EGR percentage. The optimum pilot sequences yielded a 41% reduction in NOx and 60% with smoke emissions. Also, the combination of pilot injection and EGR resulted in a drastic reduction of HC and CO emissions ∼54%.

scholarly journals Study of Indicators of CI Engine Running on Conventional Diesel and Chicken Fat Mixtures Changing EGR

2021 ◽  
Vol 11 (4) ◽  
pp. 1411
Author(s):  
Alfredas Rimkus ◽  
Tadas Vipartas ◽  
Jonas Matijošius ◽  
Saulius Stravinskas ◽  
Donatas Kriaučiūnas
Keyword(s):  
Combustion Process ◽  
Fuel Mixture ◽  
Nox Emissions ◽  
Brake Thermal Efficiency ◽  
Chicken Fat ◽  
Rate Of Heat Release ◽  
Ci Engine ◽  
Hc Emissions ◽  
Gas Recirculation ◽  
Conventional Diesel Fuel

This article presents a change in the indicators of a compression ignition (CI) engine by replacing conventional diesel fuel (D100) with pure chicken fat (F100) and mixtures of these fuels. Mixtures of diesel and fat with volume ratios of 70/30, 50/50 and 30/70 were used. Research of the fuel properties was conducted. In order to reduce the fuel viscosity, blends of fat and diesel were heated. The experimental research was conducted at different engine loads with exhaust gas recirculation (EGR) both off and on. The conducted analysis of the combustion process revealed a significant change in the rate of heat release (ROHR) when replacing diesel with chicken fat. Chicken fat was found to increase the CO2 and CO emissions, leaving hydrocarbon (HC) emissions nearly unchanged. Having replaced the D100 with diesel and chicken fat mixtures or F100, a significant reduction in smoke and nitrogen oxide (NOx) emissions was observed when EGR was off. When EGR was on, the smoke level increased, but the blends with chicken fat reduced it significantly, and the increased fat content in the fuel mixture reduced the NOx emissions. The engine’s brake specific fuel consumption (BSFC) increased while the brake thermal efficiency (BTE) decreased, having replaced conventional diesel with chicken fat due to differences in the fuel energy properties and the combustion process.

Interest Rate, Foreign Exchange Rate, and Stock Market Development in Nigeria

2018 ◽  
Vol 9 (3) ◽  
pp. 247-253 ◽  
Author(s):  
Edward Adedoyin Adebowale ◽  
Akindele Iyiola Akosile
Keyword(s):  
Exchange Rate ◽  
Interest Rate ◽  
Stock Market ◽  
Foreign Exchange ◽  
The United States ◽  
Ordinary Least Squares ◽  
Foreign Exchange Rate ◽  
Market Development ◽  
National Bureau ◽  
Stock Market Development

This research investigated the effect of interest rate and foreign exchange rate on stock market development in Nigeria. This research was centered on two research problems. First, it was whether interest rate had a significant effect on stock market development in Nigeria. Second, it was whether foreign exchange rate had a significant impact on stock market development in Nigeria. The scope of the research covered the period from 1981 to 2017. Data for this period were chosen because it covered pre and post-liberalization periods of Nigerian financial system. This research made use of ex post facto research design. Secondary data were sourced from Nigerian Stock Exchange reports, Central Bank of Nigeria statistical bulletins, and National Bureau of Statistics publications. Data were collected on Stock Market Capitalization (SMC), Prime Lending Rate (PLR) and Real Exchange Rate (RER) (Nigerian Naira in relation to American Dollars of the United States). Data analysis was carried out with Ordinary Least Squares (OLS) and Cochrane-Orcutt Iterative techniques. The findings reveal that interest rate has a significant negative effect, and foreign exchange rate has a significant positive effect on Nigerian stock market development during the period covered. It is suggested that monetary authorities should strive to formulate policies that will make interest and foreign exchange rates stable, competitive, and at a level that will stimulate the investment of funds in the stock market.

scholarly journals Combustion Optimization for Coal Fired Power Plant Boilers Based on Improved Distributed ELM and Distributed PSO

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1036 ◽  
Author(s):  
Xinying Xu ◽  
Qi Chen ◽  
Mifeng Ren ◽  
Lan Cheng ◽  
Jun Xie
Keyword(s):  
Power Plant ◽  
Combustion Process ◽  
Optimization Method ◽  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Combustion Model ◽  
Nox Emissions ◽  
Coupling Characteristics ◽  
Learning Machine ◽  
Combustion Optimization

Increasing the combustion efficiency of power plant boilers and reducing pollutant emissions are important for energy conservation and environmental protection. The power plant boiler combustion process is a complex multi-input/multi-output system, with a high degree of nonlinearity and strong coupling characteristics. It is necessary to optimize the boiler combustion model by means of artificial intelligence methods. However, the traditional intelligent algorithms cannot deal effectively with the massive and high dimensional power station data. In this paper, a distributed combustion optimization method for boilers is proposed. The MapReduce programming framework is used to parallelize the proposed algorithm model and improve its ability to deal with big data. An improved distributed extreme learning machine is used to establish the combustion system model aiming at boiler combustion efficiency and NOx emission. The distributed particle swarm optimization algorithm based on MapReduce is used to optimize the input parameters of boiler combustion model, and weighted coefficient method is used to solve the multi-objective optimization problem (boiler combustion efficiency and NOx emissions). According to the experimental analysis, the results show that the method can optimize the boiler combustion efficiency and NOx emissions by combining different weight coefficients as needed.

scholarly journals The health and relationship dynamics of late-life couples: a systematic review of the literature

2009 ◽  
Vol 29 (3) ◽  
pp. 455-480 ◽  
Author(s):  
RUTH B. WALKER ◽  
MARY A. LUSZCZ
Keyword(s):  
Systematic Review ◽  
Marital Quality ◽  
Late Life ◽  
The United States ◽  
Health It ◽  
Social Emotional ◽  
Marital Relations ◽  
The Impact ◽  
The Relationship ◽  
Adequate Communication

ABSTRACTLate-life husband and wife relationships are increasingly recognised as an important factor in promoting wellbeing, particularly in terms of the health, social, emotional, financial and practical needs of older people. Knowledge of marital dynamics and how they affect both members of a couple remains scarce. This systematic review aimed to identify and appraise research that has focused explicitly on the dynamics of the relationship, as evinced by data frombothspouses. Implementing rigorous identification strategies, 45 articles were identified and reviewed. These studies were grouped into three broad thematic areas: marital relations and satisfaction; concordance in emotional state or physical health; and the interplay between marital quality and wellbeing. The issues found to affect marital relations and satisfaction in late life included equality of roles, having adequate communication, and transitions to living apart. There is strong evidence for couple concordance in depression, that marital relationships affect ill-health, longevity and recovery from illness, and reciprocally that ill-health impacts on the marriage itself. The research also suggests important gender differences in the impact of marital dynamics on health. It has led to the conclusion that there is a need for more diverse studies of late-life marriages, particularly ones that examine the dynamics of non-traditional elderly couples and that extend beyond a predominant focus on the Caucasian population of the United States.

The impact of electronic health records on diagnosis

Diagnosis ◽  
2017 ◽  
Vol 4 (4) ◽  
pp. 211-223 ◽  
Author(s):  
Mark L. Graber ◽  
Colene Byrne ◽  
Doug Johnston
Keyword(s):  
Safety Concern ◽  
Diagnostic Error ◽  
The United States ◽  
Unintended Consequences ◽  
Diagnostic Process ◽  
Health It ◽  
Health Care Information ◽  
Health Care Information Technology ◽  
Electronic Health ◽  
The Impact

AbstractDiagnostic error may be the largest unaddressed patient safety concern in the United States, responsible for an estimated 40,000–80,000 deaths annually. With the electronic health record (EHR) now in near universal use, the goal of this narrative review is to synthesize evidence and opinion regarding the impact of the EHR and health care information technology (health IT) on the diagnostic process and its outcomes. We consider the many ways in which the EHR and health IT facilitate diagnosis and improve the diagnostic process, and conversely the major ways in which it is problematic, including the unintended consequences that contribute to diagnostic error and sometimes patient deaths. We conclude with a summary of suggestions for improving the safety and safe use of these resources for diagnosis in the future.

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