MCFC-GT Hybrid System Aiming at 70% Thermal Efficiency

2006 ◽  
Author(s):  
Eiichi Koda ◽  
Toru Takahashi
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Cell Voltage ◽  
Combined Cycle ◽  
Efficiency Improvement ◽  
Class System ◽  
Exhaust Heat ◽  
Calculation Results ◽  
Gas Turbine Exhaust ◽  
Co2 Recovery

The thermal efficiency improvement of fossil power generation is important to reduce both CO2 emission and power generating cost. To date, 60% (LHV) has been achieved with ACC (Advanced Combined Cycle) and a calculation result of 70% (LHV) or more has been reported for SOFC-GT hybrid. Then, we examined the thermal efficiency improvement considering the features of the gas turbine and the fuel cell, and designed the epoch-making cycle. By markedly improving the single-cell voltage of MCFC using oxygen as an oxidant, and having adopted a semiclosed cycle configuration in which gas turbine exhaust heat is effectively used almost completely, this cycle not only enables us to obtain an ultrahigh efficiency, but also can facilitate CO2 recovery. First, the thermal efficiency of a 300MW-class power plant using this cycle was examined, and it was confirmed that a net efficiency of 70% (HHV) or more was possible. Then, a 1MW-class system that can be realized in the near future is examined. As a result, it has been understood that it is promising as a small power supply, too. In this paper, the concept and basic configuration of this cycle were explained, and the detailed configuration and the thermal efficiency calculation results for both the 300MW-class system and the 1MW-class system are described.

Theoretical Study of the Operation Performance of a Natural Gas CCHP System under Variable Loads

2011 ◽  
Vol 71-78 ◽  
pp. 1765-1768
Author(s):  
Hong Mei Zhu ◽  
Heng Sun ◽  
Tian Quan Pan
Keyword(s):  
Natural Gas ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Theoretical Study ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Operation Performance ◽  
Exhaust Heat ◽  
Calculation Results ◽  
Cooling Loads

A theoretical study of the performance of a CCHP system using natural gas as fuel which consists of gas turbine-steam turbine combined cycle, absorption refrigeration unit and exhaust heat boiler under variable loads was carried out. Two methods to adjust the electric and cooling loads are employed here. One method is to increase the outlet pressure of the steam turbine in the Rankine cycle. Another way is to change the air coefficient of the gas turbine. The calculation results show that the first method can obtain higher energy efficient and is the preferred method. The second way can be employed in case that further more cooling is required.

System Study on Partial Gasification Combined Cycle With CO2 Recovery

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
Yujie Xu ◽  
Hongguang Jin ◽  
Rumou Lin ◽  
Wei Han
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Energy Utilization ◽  
Working Fluid ◽  
The Novel ◽  
Integrated Gasification Combined Cycle ◽  
Partial Gasification ◽  
Co2 Recovery

A partial gasification combined cycle with CO2 recovery is proposed in this paper. Partial gasification adopts cascade conversion of the composition of coal. Active composition of coal is simply gasified, while inactive composition, that is char, is burnt in a boiler. Oxy-fuel combustion of syngas produces only CO2 and H2O, so the CO2 can be separated through cooling the working fluid. This decreases the amount of energy consumption to separate CO2 compared with conventional methods. The novel system integrates the above two key technologies by injecting steam from a steam turbine into the combustion chamber of a gas turbine to combine the Rankine cycle with the Brayton cycle. The thermal efficiency of this system will be higher based on the cascade utilization of energy level. Compared with the conventional integrated gasification combined cycle (IGCC), the compressor of the gas turbine, heat recovery steam generator (HRSG) and gasifier are substituted for a pump, reheater, and partial gasifier, so the system is simplified obviously. Furthermore, the novel system is investigated by means of energy-utilization diagram methodology and provides a simple analysis of their economic and environmental performance. As a result, the thermal efficiency of this system may be expected to be 45%, with CO2 recovery of 41.2%, which is 1.5–3.5% higher than that of an IGCC system. At the same time, the total investment cost of the new system is about 16% lower than that of an IGCC. The comparison between the partial gasification technology and the IGCC technology is based on the two representative cases to identify the specific feature of the proposed system. The promising results obtained here with higher thermal efficiency, lower cost, and less environmental impact provide an attractive option for clean-coal utilization technology.

System Study on Partial Gasification Combined Cycle With CO2 Recovery

2006 ◽  
Author(s):  
Yujie Xu ◽  
Hongguang Jin ◽  
Rumou Lin ◽  
Wei Han
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Energy Utilization ◽  
Working Fluid ◽  
The Novel ◽  
Attractive Option ◽  
Partial Gasification ◽  
Co2 Recovery

A partial gasification combined cycle with CO2 recovery is proposed in this paper. Partial gasification adopts cascade conversion of the composition of coal. Active composition of coal is simply gasified, while inactive composition, that is char, is burnt in a boiler. Oxy-fuel combustion of syngas produces only CO2 and H2O, so the CO2 can be separated through cooling the working fluid. This decreases the amount of energy consumed to separate CO2 compared with conventional methods. The novel system integrates the above two key technologies, by injecting steam from a steam turbine into the combustion chamber of a gas turbine, to combine the Rankine cycle with the Brayton cycle. The thermal efficiency of this system will be higher based on the cascade utilization of energy level. Compared to the conventional IGCC, the compressor of the gas turbine, HRSG and gasifier are substituted for a pump, reheater and partial gasifier, so the system is simplified obviously. Furthermore, the novel system is investigated by means of EUD (Energy-Utilization Diagram) methodology and provides a simple analysis of their economic and environmental performance. As a result, the thermal efficiency of this system may be expected to be 46%, with recovery of 50% of CO2, which is 3–5% higher than that of an IGCC system. At the same time, the total investment cost of the new system is about 21.5% lower than that of an IGCC. The promising results obtained here with higher thermal efficiency, lower cost and less environmental impact provide an attractive option for clean coal utilization technology.

Mirror Gas Turbines: A Newly Proposed Method of Exhaust Heat Recovery

2000 ◽  
Vol 123 (3) ◽  
pp. 481-486 ◽  
Author(s):  
S. Fujii ◽  
K. Kaneko ◽  
K. Otani ◽  
Y. Tsujikawa
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Preliminary Test ◽  
Combined Cycle ◽  
Conceptual Combination ◽  
Steam Turbines ◽  
Generation Plant ◽  
Exhaust Heat ◽  
Actual Operation

A new conceptual combination of Brayton and inverted Brayton cycles with a heat sink by intercooling, which is dubbed the mirror gas turbine, has been evaluated and proposed in this paper. Prior to such evaluations, a preliminary test on the inverted cycle without intercooling was made experimentally to confirm the actual operation. The conventional method of recuperation in gas turbines can be replaced by the mirror gas turbine with a low working temperature of about 450°C at heat exchanger. The combined cycle of Brayton/Rankine for electricity generation plant may be improved by our concept into a system with steam turbines completely removed and with still high thermal efficiency. Ultra-micro turbines will be possible, producing the output power less than 10 kW as well as thermal efficiency of 20 percent.

scholarly journals General Design Considerations for Gas Turbine Waste Heat Steam Generators

1968 ◽  
Author(s):  
W. V. Hambleton
Keyword(s):  
Gas Turbine ◽  
Heat Recovery ◽  
Waste Heat ◽  
Steam Generation ◽  
Steam Generators ◽  
Design Considerations ◽  
Exhaust Heat ◽  
Gas Turbine Exhaust ◽  
Exhaust Heat Recovery ◽  
Turbine Exhaust

This paper represents a study of the overall problems encountered in large gas turbine exhaust heat recovery systems. A number of specific installations are described, including systems recovering heat in other than the conventional form of steam generation.

scholarly journals Gas Turbine Heat Recovery Steam Generators for Combined Cycles Natural or Forced Circulation Considerations

1988 ◽  
Author(s):  
Akber Pasha
Keyword(s):  
Gas Turbine ◽  
Steam Generator ◽  
Heat Recovery ◽  
Power Plants ◽  
Natural Circulation ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Steam Generators ◽  
Forced Circulation ◽  
Gas Turbine Exhaust

In recent years the combined cycle has become a very attractive power plant arrangement because of its high cycle efficiency, short order-to-on-line time and flexibility in the sizing when compared to conventional steam power plants. However, optimization of the cycle and selection of combined cycle equipment has become more complex because the three major components, Gas Turbine, Heat Recovery Steam Generator and Steam Turbine, are often designed and built by different manufacturers. Heat Recovery Steam Generators are classified into two major categories — 1) Natural Circulation and 2) Forced Circulation. Both circulation designs have certain advantages, disadvantages and limitations. This paper analyzes various factors including; availability, start-up, gas turbine exhaust conditions, reliability, space requirements, etc., which are affected by the type of circulation and which in turn affect the design, price and performance of the Heat Recovery Steam Generator. Modern trends around the world are discussed and conclusions are drawn as to the best type of circulation for a Heat Recovery Steam Generator for combined cycle application.

scholarly journals Thermodynamic analysis of high temperature nuclear reactor coupled with advanced gas turbine combined cycle

2019 ◽  
Vol 23 (Suppl. 4) ◽  
pp. 1187-1197 ◽  
Author(s):  
Marek Jaszczur ◽  
Michal Dudek ◽  
Zygmunt Kolenda
Keyword(s):  
High Temperature ◽  
Power Plant ◽  
Gas Turbine ◽  
Thermodynamic Analysis ◽  
Thermal Efficiency ◽  
Nuclear Power ◽  
Coal Gasification ◽  
Nuclear Reactor ◽  
Combined Cycle ◽  
Oil Processing

One of the most advanced and most effective technology for electricity generation nowadays based on a gas turbine combined cycle. This technology uses natural gas, synthesis gas from the coal gasification or crude oil processing products as the energy carriers but at the same time, gas turbine combined cycle emits SO2, NOx, and CO2 to the environment. In this paper, a thermodynamic analysis of environmentally friendly, high temperature gas nuclear reactor system coupled with gas turbine combined cycle technology has been investigated. The analysed system is one of the most advanced concepts and allows us to produce electricity with the higher thermal efficiency than could be offered by any currently existing nuclear power plant technology. The results show that it is possible to achieve thermal efficiency higher than 50% what is not only more than could be produced by any modern nuclear plant but it is also more than could be offered by traditional (coal or lignite) power plant.

Effect of Coolant Injection Angle on Nozzle Endwall Film Cooling: Experimental and Numerical Analysis in Linear Cascade

2018 ◽  
Author(s):  
Lamyaa El-Gabry ◽  
Hongzhou Xu ◽  
Kevin Liu ◽  
James Chang ◽  
Michael Fox
Keyword(s):  
Flow Field ◽  
Gas Turbine ◽  
Surface Film ◽  
Combined Cycle ◽  
Gas Temperature ◽  
Injection Angle ◽  
Linear Cascade ◽  
Cfd Models ◽  
Coolant Injection ◽  
Exhaust Heat

Gas turbine components can withstand gas temperatures exceeding the melting point of the alloys they’re made of due to increasingly effective cooling methods. Increasing the operating temperature of a gas turbine is key to improving its power density and exhaust heat for steam or combined-cycle efficiency. In the turbine, the component that experiences the highest gas temperature is the vane directly downstream of the combustor; the most complex flow field in a vane occurs near the endwall. In this study, an experimental investigation is carried out to determine the effect of coolant injection angle and mass flow ratio on film effectiveness on the endwall using the pressure sensitive paint technique for various configurations of jump cooling hole configurations. Two rows of angled holes are upstream of an uncooled vane in a three-vane linear cascade. Injection angle including compound angle is varied from 20 to 60 and coolant to mainstream massflux ratio is varied from 0.5% to 3%. Contours of endwall surface film effectiveness are presented along with span-averaged film effectiveness. CFD models of the cascade are developed using a commercial solver to predict film effectiveness for some of the test conditions and comparisons are made between the experimental and numerical results. The CFD models provide further insight into the flow field and explain trends observed in the experiment by understanding the interaction of jump coolant flow with the 3D endwall mainstream flows.

The Elephant in the Room–Gas Turbine Power

2010 ◽  
Vol 132 (12) ◽  
pp. 57-57
Author(s):  
Lee S. Langston
Keyword(s):  
Power Plant ◽  
Electric Power ◽  
Gas Turbine ◽  
Power Plants ◽  
Electrical Power ◽  
Electric Power Industry ◽  
Hydrocarbon Fuel ◽  
Combined Cycle ◽  
Electrical Generator ◽  
Gas Turbine Exhaust

This article presents an overview of gas turbine combined cycle (CCGT) power plants. Modern CCGT power plants are producing electric power as high as half a gigawatt with thermal efficiencies approaching the 60% mark. In a CCGT power plant, the gas turbine is the key player, driving an electrical generator. Heat from the hot gas turbine exhaust is recovered in a heat recovery steam generator, to generate steam, which drives a steam turbine to generate more electrical power. Thus, it is a combined power plant burning one unit of fuel to supply two sources of electrical power. Most of these CCGT plants burn natural gas, which has the lowest carbon content of any other hydrocarbon fuel. Their near 60% thermal efficiencies lower fuel costs by almost half compared to other gas-fired power plants. Their installed capital cost is the lowest in the electric power industry. Moreover, environmental permits, necessary for new plant construction, are much easier to obtain for CCGT power plants.

PerformanceAnalysis of Integrated Solar Combined Cycle Power Plant for Dhahran, Saudi Arabia

2014 ◽  
Vol 492 ◽  
pp. 568-573 ◽  
Author(s):  
Yinka Sofihullahi Sanusi ◽  
Palanichamy Gandhidasan ◽  
Esmail M.A. Mokheimer
Keyword(s):  
Saudi Arabia ◽  
Gas Turbine ◽  
Combined Cycle ◽  
Plant Performance ◽  
Steam Turbines ◽  
Steam Generation ◽  
Power Requirement ◽  
Gas Turbine Exhaust ◽  
Auxiliary Heater ◽  
Solar Field

Saudi Arabia is blessed with abundant solar energywhichcan be use to meet its ever increasing power requirement. In this regard, the energy analysis and plant performance of integrated solar combined cycle (ISCC) plant with direct steam generation (DSG) was carried out for Dhahran, Saudi Arabia using four representative months of March, June, September and December. The plant consists of 180MW conventional gas turbine plant and two steam turbines of 80MW and 60MW powered by the solar field and gas turbine exhaust. With high insolation during the summer month of June the plant can achieve up to 25% of solar fraction with ISCC plant efficiency of 45% as compared to gas turbine base of 38%.This can however be improved by increasing the number of collectors or/and the use of auxiliary heater .

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