Reaction of Fuel NOx Formation for Gas Turbine Conditions

1998 ◽  
Vol 120 (3) ◽  
pp. 474-480 ◽  
Author(s):  
T. Nakata ◽  
M. Sato ◽  
T. Hasegawa
Keyword(s):  
Gas Turbine ◽  
Coal Gasification ◽  
Combustion Process ◽  
Combined Cycle ◽  
Inlet Section ◽  
Mixing Condition ◽  
Nox Formation ◽  
Air Inlet ◽  
Secondary Air ◽  
Fuel Nox

Ammonia contained in coal-gasified fuel is converted to nitrogen oxides (NOx) in the combustion process of a gas turbine in integrated coal gasification combined cycle (IGCC) system. Research data on fuel-NOx formation are insufficient, and there still remains a wide explored domain. The present research aims at obtaining fundamental knowledge of fuel-NOx formation characteristics by applying reaction kinetics to gas turbine conditions. An instantaneous mixing condition was assumed in the cross section of a gas turbine combustor and both gradual mixing condition and instantaneous mixing condition were assumed at secondary air inlet section. The results may be summarized as follows: (1) in the primary combustion zone under fuel rich condition, HCN and other intermediate products are formed as ammonia contained in the fuel decomposes; (2) formation characteristics of fuel-NOx are affected by the condition of secondary air mixing; and (3) the conversion ratio from ammonia to NOx declines as the pressure inside the combustor rises under the condition of gradual mixing at the secondary air inlet. These results obtained agreed approximately with the experimentation.

A Study on Low NOx Combustion in LBG-Fueled 1500°C-Class Gas Turbine

1994 ◽  
Author(s):  
Toshihiko Nakata ◽  
Mikio Sato ◽  
Toru Ninomiya ◽  
Takeharu Hasegawa
Keyword(s):  
Power Generation ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Coal Gasification ◽  
Combustion Process ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Gas Temperature ◽  
Secondary Air

Developing integrated coal gasification combined cycle systems ensures cost-effective and environmentally sound options for supplying future power generation needs. The reduction of NOx emissions and increasing the inlet temperature of gas turbines are the most significant issues in gas turbine development in an Integrated Coal Gasification Combined Cycle (IGCC) power generation systems. The coal gasified fuel, which is produced in a coal gasifier of air-blown entrained-flow type has calorific value as low as 1/10 of natural gas. Furthermore the fuel gas contains ammonia when a gas cleaning system is a hot type, and ammonia will be converted to nitrogen oxides in the combustion process of a gas turbine. This study is performed in a 1500°C-class gas turbine combustor firing low-Btu coal-gasified fuel in IGCC systems. An advanced rich-lean combustor of 150-MW class gas turbine was designed to hold stable combustion burning low-Btu gas and to reduce fuel NOx emission that is produced from the ammonia in the fuel. The main fuel and the combustion air is supplied into fuel-rich combustion chamber with strong swirl flow and make fuel-rich flame to decompose ammonia into intermediate reactants such as NHi and HCN. The secondary air is mixed with primary combustion gas dilatorily to suppress the oxidization of ammonia reactants in fuel-lean combustion chamber and to promote a reducing process to nitrogen. By testing it under atmospheric pressure conditions, the authors have obtained a very significant result through investigating the effect of combustor exit gas temperature on combustion characteristics. Since we have ascertained the excellent performance of the tested combustor through our extensive investigation, we wish to report on the results.

Combustion Performance in a Semiclosed Cycle Gas Turbine for IGCC Fired With CO-Rich Syngas and Oxy-Recirculated Exhaust Streams

2012 ◽  
Vol 134 (9) ◽  
Author(s):  
Takeharu Hasegawa
Keyword(s):  
Gas Turbine ◽  
Coal Gasification ◽  
Combustion Process ◽  
Equilibrium Concentration ◽  
Combined Cycle ◽  
Reaction Heat ◽  
Highly Efficient ◽  
Coal Fuel ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

Our study found that burning a CO-rich gasified coal fuel, derived from an oxygen–CO2 blown gasifier, with oxygen under stoichiometric conditions in a closed cycle gas turbine produced a highly-efficient, oxy-fuel integrated coal gasification combined cycle (IGCC) power generation system with CO2 capture. We diluted stoichiometric combustion with recycled gas turbine exhaust and adjusted for given temperatures. Some of the exhaust was used to feed coal into the gasifier. In doing so, we found it necessary to minimize not only CO and H2 of unburned fuel constituents but also residual O2, not consumed in the gas turbine combustion process. In this study, we examined the emission characteristics of gasified-fueled stoichiometric combustion with oxygen through numerical analysis based on reaction kinetics. Furthermore, we investigated the reaction characteristics of reactant gases of CO, H2, and O2 remaining in the recirculating gas turbine exhaust using present numerical procedures. As a result, we were able to clarify that since fuel oxidation reaction is inhibited due to reasons of exhaust recirculation and lower oxygen partial pressure, CO oxidization is very sluggish and combustion reaction does not reach equilibrium at the combustor exit. In the case of a combustor exhaust temperature of 1573 K (1300 °C), we estimated that high CO exhaust emissions of about a few percent, in tens of milliseconds, corresponded to the combustion gas residence time in the gas turbine combustor. Combustion efficiency was estimated to reach only about 76%, which was a lower value compared to H2/O2-fired combustion while residual O2 in exhaust was 2.5 vol%, or five times as much as the equilibrium concentration. On the other hand, unburned constituents in an expansion turbine exhaust were slowed to oxidize in a heat recovery steam generator (HRSG) flue processing, and exhaust gases reached equilibrium conditions. In this regard, however, reaction heat in HRSG could not devote enough energy for combined cycle thermal efficiency, making advanced combustion technology necessary for achieving highly efficient, oxy-fuel IGCC.

scholarly journals Design and Test of a Low-NOx Advanced Rich-Lean Combustor for LBG Fueled 1300°C-Class Gas Turbine

1992 ◽  
Author(s):  
T. Nakata ◽  
M. Sato ◽  
T. Ninomiya ◽  
T. Yoshine ◽  
M. Yamada
Keyword(s):  
Gas Turbine ◽  
Coal Gasification ◽  
Combustion Process ◽  
Calorific Value ◽  
Ammonia Concentration ◽  
Combined Cycle ◽  
Combustion Stability ◽  
Fuel Gas ◽  
Gas Cleaning ◽  
Coal Gasifier

Research and development of an IGCC (Integrated Coal Gasification Combined Cycle) power generation system is being carried out as one of the advanced coal utilization technology in Japan. The coal gasified fuel, which is produced in a coal gasifier of air-blown entrained-flow type has calorific value as low as 1/10 of LNG. Furthermore, the fuel gas contains ammonia when a gas cleaning system is a hot type, and ammonia will be converted to nitrogen oxides in the combustion process of a gas turbine. The authors have designed and made an 1300°C-class advanced rich-lean combustor mainly designed for achieving low fuel-NOx combustion. By testing it under atmospheric pressure conditions, we have successfully reduced the NOx emissions (to 60 ppm corrected at 16 percent O2) by more than half the level previously achieved when the ammonia concentration was 1000 ppm. Combustion stability was adequate even when the calorific value of the fuel decreased to 2700 kJ/m3N.

A Study on Low NOx Combustion in LBG-Fueled 1500°C-Class Gas Turbine

1996 ◽  
Vol 118 (3) ◽  
pp. 534-540 ◽  
Author(s):  
T. Nakata ◽  
M. Sato ◽  
T. Ninomiya ◽  
T. Hasegawa
Keyword(s):  
Power Generation ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Coal Gasification ◽  
Combustion Process ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Nox Emissions ◽  
Gas Temperature

Developing integrated coal gasification combined-cycle systems ensures cost-effective and environmentally sound options for supplying future power generation needs. The reduction of NOx emissions and increasing the inlet temperature of gas turbines are the most significant issues in gas turbine development in Integrated Coal Gasification Combined Cycle (IGCC) power generation systems. The coal gasified fuel, which is produced in a coal gasifier of an air-blown entrained-flow type has a calorific value as low as 1/10 of natural gas. Furthermore, the fuel gas contains ammonia when a gas cleaning system is a hot type, and ammonia will be converted to nitrogen oxides in the combustion process of a gas turbine. This study is performed in a 1500°C-class gas turbine combustor firing low-Btu coal-gasified fuel in IGCC systems. An advanced rich-lean combustor of 150-MW class gas turbine was designed to hold stable combustion burning low-Btu gas and to reduce fuel NOx emissions from the ammonia in the fuel. The main fuel and the combustion air are supplied into a fuel-rich combustion chamber with strong swirl flow and make fuel-rich flame to decompose ammonia into intermediate reactants such as NHi and HCN. The secondary air is mixed with primary combustion gas dilatorily to suppress the oxidization of ammonia reactants in fuel-lean combustion chamber and to promote a reducing process to nitrogen. By testing under atmospheric pressure conditions, the authors have obtained a very significant result through investigating the effect of combustor exit gas temperature on combustion characteristics. Since we have ascertained the excellent performance of the tested combustor through our extensive investigation, we wish to report on the results.

scholarly journals Coal Gaseous Fueled, Low Fuel-NOx Gas Turbine Combustor

1990 ◽  
Author(s):  
M. Sato ◽  
T. Ninomiya ◽  
T. Nakata ◽  
T. Yoshine ◽  
M. Yamada ◽  
...  
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Coal Gasification ◽  
Combustion Method ◽  
Combined Cycle ◽  
Gas Turbine Combustor ◽  
Lean Combustion ◽  
Combustion Technology ◽  
Fuel Nox

From the view point of future coal utilization technology for the thermal power generation systems, the coal gasification combined cycle system has drawn special interest recently. In the coal gasification combined cycle power generation system, it is necessary to develop a high temperature gas turbine combustor using a low–BTU gas (LBG) which has high thermal efficiency and low emissions. In Japan a development program on the coal gasification combined cycle power generation system has started in 1985 by the national government and Japanese electric companies. In this program, is planned to develop the 1300 °C class gas turbines. However, in the case of using a hot type fuel gas cleaning system, the coal gas fuel to be supplied to gas turbines will contain ammonia. Ammonia will be converted to nitric oxides in the combustion process in gas turbines. Therefore, low fuel–NOx combustion technology is one of the most important research subjects. This paper describes low fuel–NOx combustion technology for 1300 °C class gas turbine combustor using low BTU coal gas fuel. Authors have showed that the rich–lean combustion method is effective to decrease fuel–NOx (1). In general in rich–lean combustion method, the fuel–NOx decreases, as the primary zone becomes richer. But flameholding becomes very difficult in even rich primary zone. For this reason this combustor was designed to have a flameholder with pilot flame. Combustion tests were conducted by using a full scale combustor used in 150 MW gas turbine at the atmospheric pressure condition.

Effect of Pressure on Combustion Characteristics in LBG-Fueled 1300°C-Class Gas Turbine

1994 ◽  
Vol 116 (3) ◽  
pp. 554-558 ◽  
Author(s):  
T. Nakata ◽  
M. Sato ◽  
T. Ninomiya ◽  
T. Yoshine ◽  
M. Yamada
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Coal Gasification ◽  
Combustion Process ◽  
Combined Cycle ◽  
Combustion Characteristics ◽  
Inlet Temperature ◽  
Effect Of Pressure ◽  
Coal Gasifier

Developing integrated coal gasification combined cycle systems ensures that Japan will have cost-effective and environmentally sound options for supplying future power generation needs. Reduction of NOx emissions and increasing the inlet temperature of gas turbines are the most significant issues in gas turbine development in IGCC. The coal gasified fuel, which is produced in a coal gasifier of air blown entrained-flow type has a calorific value as low as 1/10 of natural gas. Furthermore, the fuel gas contains ammonia when a gas cleaning system is a hot type, and ammonia will be converted to nitrogen oxides in the combustion process of a gas turbine. The study is performed in 1300°C-class gas turbine combustor firing coal-gasifier fuel in IGCC power generation systems. In the previous study [1] the advanced rich-lean combustor of 150-MW class gas turbine was designed to hold stable combustion burning low-Btu gas fuel and to reduce fuel NOx emission that is produced from the ammonia in the fuel. By testing it under atmospheric pressure conditions, we have studied the effects of fuel parameters on combustor performances and listed the basic data for development applications. In this study, by testing it under pressurized conditions, we have obtained a very significant result through investigating the effect of pressure on combustion characteristics and wish to provide herein a summary of our findings.

scholarly journals Effect of Pressure on Combustion Characteristics in LBG–Fueled 1300°C–Class Gas Turbine

1993 ◽  
Author(s):  
Toshihiko Nakata ◽  
Mikio Sato ◽  
Toru Ninomiya ◽  
Toshiyuki Yoshine ◽  
Masahiko Yamada
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Coal Gasification ◽  
Combustion Process ◽  
Combined Cycle ◽  
Combustion Characteristics ◽  
Inlet Temperature ◽  
Gas Cleaning ◽  
Effect Of Pressure

Developing integrated coal gasification combined cycle systems ensures that Japan will have cost–effective and environmentally sound options for supplying future power generation needs. The reduction of NOx emissions and increasing the inlet temperature of gas turbines are the most significant issues in gas turbine development in IGCC. The coal gasified fuel, which is produced in a coal gasifier of air–blown entrained–flow type has calorific value as low as 1/10 of natural gas. Furthermore the fuel gas contains ammonia when a gas cleaning system is a hot type, and ammonia will be converted to nitrogen oxides in the combustion process of a gas turbine. The study is performed in 1300°C–class gas turbine combustor firing coal–gasified fuel in IGCC power generation systems. In the previous study the advanced rich–lean combustor of 150–MW class gas turbine was designed to hold stable combustion burning low–Btu gas fuel and to reduce fuel NOx emission that is produced from the ammonia in the fuel. By testing it under atmospheric pressure conditions, we have studied the effects of fuel parameters on combustor performances and listed the basic data for development applications. In this study, by testing it under pressurized conditions, we have obtained a very significant result through investigating the effect of pressure on combustion characteristics and wish to provide herein a summary of our findings.

scholarly journals Comprehensive Thermodynamic Analysis of the Humphrey Cycle for Gas Turbines with Pressure Gain Combustion

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3521 ◽  
Author(s):  
Panagiotis Stathopoulos
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Process ◽  
Ideal Gas ◽  
Point Of View ◽  
Pressure Gain Combustion ◽  
Combustion Technology ◽  
Secondary Air ◽  
And Performance ◽  
The Impact

Conventional gas turbines are approaching their efficiency limits and performance gains are becoming increasingly difficult to achieve. Pressure Gain Combustion (PGC) has emerged as a very promising technology in this respect, due to the higher thermal efficiency of the respective ideal gas turbine thermodynamic cycles. Up to date, only very simplified models of open cycle gas turbines with pressure gain combustion have been considered. However, the integration of a fundamentally different combustion technology will be inherently connected with additional losses. Entropy generation in the combustion process, combustor inlet pressure loss (a central issue for pressure gain combustors), and the impact of PGC on the secondary air system (especially blade cooling) are all very important parameters that have been neglected. The current work uses the Humphrey cycle in an attempt to address all these issues in order to provide gas turbine component designers with benchmark efficiency values for individual components of gas turbines with PGC. The analysis concludes with some recommendations for the best strategy to integrate turbine expanders with PGC combustors. This is done from a purely thermodynamic point of view, again with the goal to deliver design benchmark values for a more realistic interpretation of the cycle.

scholarly journals Simulation and optimization integrated gasification combined cycle by used aspen hysys and aspen plus

2015 ◽  
Vol 3 (1) ◽  
pp. 178
Author(s):  
Mohsen Darabi ◽  
Mohammad Mohammadiun ◽  
Hamid Mohammadiun ◽  
Saeed Mortazavi ◽  
Mostafa Montazeri
Keyword(s):  
Gas Turbine ◽  
Coal Gasification ◽  
Aspen Plus ◽  
Combined Cycle ◽  
Parameters Estimation ◽  
Integrated Gasification Combined Cycle ◽  
Support Tool ◽  
Simulation And Optimization ◽  
Aspen Hysys ◽  
Integrated Gasification

<p>Electricity is an indispensable amenity in present society. Among all those energy resources, coal is readily available all over the world and has risen only moderately in price compared with other fuel sources. As a result, coal-fired power plant remains to be a fundamental element of the world's energy supply. IGCC, abbreviation of Integrated Gasification Combined Cycle, is one of the primary designs for the power-generation market from coal-gasification. This work presents a in the proposed process, diluted hydrogen is combusted in a gas turbine. Heat integration is central to the design. Thus far, the SGR process and the HGD unit are not commercially available. To establish a benchmark. Some thermodynamic inefficiencies were found to shift from the gas turbine to the steam cycle and redox system, while the net efficiency remained almost the same. A process simulation was undertaken, using Aspen Plus and the engineering equation solver (EES).The The model has been developed using Aspen Hysys® and Aspen Plus®. Parts of it have been developed in Matlab, which is mainly used for artificial neural network (ANN) training and parameters estimation. Predicted results of clean gas composition and generated power present a good agreement with industrial data. This study is aimed at obtaining a support tool for optimal solutions assessment of different gasification plant configurations, under different input data sets.</p>

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