scholarly journals Conceptual Design of a Pulverized Coal Furnace for a Utility Size Closed-Cycle, Gas-Turbine Power Plant

1979 ◽  
Author(s):  
H. J. Strumpf

A study has recently been completed for the Department of Energy on the conceptual design of coal-fired, closed-cycle, gas-turbine power plants that operate at high turbine-inlet temperatures and use air as the cycle fluid. This paper describes the design of one type of heater system for such a power plant — a pulverized coal furnace. Designs are presented for a 1550 F (843 C) turbine inlet temperature cycle that utilizes metallic superalloy heat exchanger tubes and a 1750 F (954 C) turbine inlet temperature cycle that utilizes ceramic heat exchanger tubes. The heaters consist of two sections — a radiant section where heat is transferred primarily by radiation from the pulverized coal luminous flame, and a convective section where heat is transferred primarily by forced convection from the nonluminous combustion gas. To maintain flame stability in the furnace, a minimum power density criterion must be met. This requires modularization of the radiant heaters.

2011 ◽  
Vol 189-193 ◽  
pp. 3007-3013 ◽  
Author(s):  
M.M. Rahman ◽  
Thamir K. Ibrahim ◽  
K. Kadirgama ◽  
R. Mamat ◽  
Rosli A. Bakar

This paper presents the effect of ambient temperature and operation conditions (compression ratio, turbine inlet temperature, air to fuel ratio and efficiency of compressor and turbine) on the performance of gas turbine power plant. The computational model was developed utilizing the MATLAB codes. Turbine work found to be decreases as ambient temperature increases as well as the thermal efficiency decreases. It can be seen that the thermal efficiency increases linearly with increases of compression ratio while decreases of ambient temperature. The specific fuel consumption increases with increases of ambient temperature and lower turbine inlet temperature. The effect of variation of SFC is more significance at higher ambient temperature than lower temperature. It is observed that the thermal efficiency linearly increases at lower compressor ratio as well as higher turbine inlet temperature until certain value of compression ratio. The variation of thermal efficiency is more significance at higher compression ratio and lower turbine inlet temperature. Even though at lower turbine inlet temperature is decrement the thermal efficiency dramatically and the SFC decreases linearly with increases of compression ratio and turbine inlet temperature at lower range until certain value then increases dramatically for lower turbine inlet temperature.


Author(s):  
Feliciano Pava´n ◽  
Marco Romo ◽  
Juan Prince

The present paper is a thermodynamics analysis, i.e. both energy and exergy analyses for a natural gas based combined cycle power plant. The analysis was performed for an existing 240 MW plant, where the steam cycle reduces the irreversibilities during heat transfer from gas to water/steam. The effect of operating variables such as pressure ratio, gas turbine inlet temperature on the performance of combined cycle power plant has been investigated. The pressure ratio and maximum temperature (gas turbine inlet temperature) are identified as the dominant parameters having impact on the combined cycle plant performance. The work output of the topping cycle is found to increase with pressure ratio, while for the bottoming cycle it decreases. However, for the same gas turbine inlet temperature the overall work output of the combined cycle plant increases up to a certain pressure ratio, and thereafter not much increase is observed. The exergy losses of the individual components in the plant are evaluated based on second law of thermodynamics. The present results form a basis on which further work can be conducted to improve the performance of these units.


Author(s):  
Yukiko Agata ◽  
Shinichi Akabayashi ◽  
Shinya Ishikawa ◽  
Yuji Matsumura

Decreases in inlet mass flow due to rises in ambient temperature during the summer lead to a decrease in the power output of gas turbines. In order to recover lost output, this study employed a mist atomization system using efficient spray nozzles, developed mainly as a technology for urban heat-island mitigation, installing the system in an inlet air flow path of a gas turbine at Higashi-Niigata thermal power station No.4 train, a commercial plant. The nozzles can efficiently decrease inlet air temperature of gas turbines because of their minute atomized mist size and highly-efficient evaporation properties. A flow path in the upstream of the inlet filter was used for mist evaporation by the system. This path is unique to the power plant, and is intended to prevent snow particles from direct entry. Model and field tests to confirm safe and effective operation of the system developed were performed in order to address possible concerns associated with the introduction of this system. As a basic consideration, wind tunnel experiments using nozzles were performed. Through the experiments, the most suitable nozzles were chosen, and effectiveness of the mist atomization was evaluated. The basic specifications of the system were determined from the evaluation results. At the same time, flow-field in the inlet air channel of the intended gas turbine was analyzed, and positioning of the atomization devices optimized. The mist atomization system that was developed was installed in a gas turbine at the power plant. To prevent excessive atomization from possibly causing erosion, a target value of 95% humidity at the compressor inlet was set, and a thermo-hygrometer was installed downstream of the inlet silencer to monitor humidity. As a result of the operation, no signs of erosion were detected in a major inspection conducted about one year following the introduction of the system. Another concern had to do with immediate changes in the state of the gas turbine due to mist atomization stoppages. To evaluate effects of the stoppages, field tests in the plant were performed, resulting in no significant changes in turbine inlet temperature and exhaust gas temperature. Combustion pressure oscillations was also not observed. From these results, it has been confirmed that the system can be operated safely. After activating the atomization system, inlet temperature decreased by up to about 7.5 degrees Celsius and power output increased by up to 13 MW in the gas turbine.


Author(s):  
Phillip Waniczek ◽  
Dirk Therkorn ◽  
Darrel Lilley

This paper describes a method that optimizes the commercial benefit by modifying gas turbine control parameters like turbine inlet temperature and variable inlet guide vane position for any dispatched power plant load. The method is a trade-off between best efficiency in the component characteristic together with higher efficiency due to increased turbine inlet temperature and lifetime. With commercial data, both effects are transferred into costs and an optimization routine identifies controller settings for minimum power plant operation cost. Test cases demonstrate the advantage of the operational cost optimization. Costs are calculated based on historic plant data with the original and the optimized operation concept. Although savings per operating hour are small, the accumulated savings over years or major inspection intervals are significant. It could be demonstrated that in regions with high fuel prices the commercial benefit of the optimized gas turbine operating concept sums up to “several million dollars” of savings. Parametric and sensitivity studies show the effect of the main parameters. Dispatch power optimization is not subject of the presented model, but can be implemented on top of the proposed concept. All in all, this work demonstrates and quantifies the commercial benefits when todays and future digital industrial capabilities are applied to gas turbine operation concepts and strategies. The proposed digital approach has the advantage of minimum investment and is attractive for gas turbine operators to generate electricity at lower costs and fuel consumption, increasing revenues and minimizing environmental impact.


Author(s):  
Anoop Kumar Shukla ◽  
Onkar Singh

Gas/steam combined cycle power plants are extensively used for power generation across the world. Today’s power plant operators are persistently requesting enhancement in performance. As a result, the rigour of thermodynamic design and optimization has grown tremendously. To enhance the gas turbine thermal efficiency and specific power output, the research and development work has centered on improving firing temperature, cycle pressure ratio, adopting improved component design, cooling and combustion technologies, and advanced materials and employing integrated system (e.g. combined cycles, intercooling, recuperation, reheat, chemical recuperation). In this paper a study is conducted for combining three systems namely inlet fogging, steam injection in combustor, and film cooling of gas turbine blade for performance enhancement of gas/steam combined cycle power plant. The evaluation of the integrated effect of inlet fogging, steam injection and film cooling on the gas turbine cycle performance is undertaken here. Study involves thermodynamic modeling of gas/steam combined cycle system based on the first law of thermodynamics. The results obtained based on modeling have been presented and analyzed through graphical depiction of variations in efficiency, specific work output, cycle pressure ratio, inlet air temperature & density variation, turbine inlet temperature, specific fuel consumption etc.


Author(s):  
Katsuyoshi Tada ◽  
Kei Inoue ◽  
Tomo Kawakami ◽  
Keijiro Saitoh ◽  
Satoshi Tanimura

Gas-turbine combined-cycle (GTCC) power generation is clean and efficient, and its demand will increase in the future from economic and social perspectives. Raising turbine inlet temperature is an effective way to increase combined cycle efficiency and contributes to global environmental conservation by reducing CO2 emissions and preventing global warming. However, increasing turbine inlet temperature can lead to the increase of NOx emissions, depletion of the ozone layer and generation of photochemical smog. To deal with this issue, MHPS (MITSUBISHI HITACHI POWER SYSTEMS) and MHI (MITSUBISHI HEAVY INDUSTRIES) have developed Dry Low NOx (DLN) combustion techniques for high temperature gas turbines. In addition, fuel flexibility is one of the most important features for DLN combustors to meet the requirement of the gas turbine market. MHPS and MHI have demonstrated DLN combustor fuel flexibility with natural gas (NG) fuels that have a large Wobbe Index variation, a Hydrogen-NG mixture, and crude oils.


Author(s):  
Hideto Moritsuka

In order to estimate the possibility to improve thermal efficiency of power generation use gas turbine combined cycle power generation system, benefits of employing the advanced gas turbine technologies proposed here have been made clear based on the recently developed 1500C-class steam cooling gas turbine and 1300C-class reheat cycle gas turbine combined cycle power generation systems. In addition, methane reforming cooling method and NO reducing catalytic reheater are proposed. Based on these findings, the Maximized efficiency Optimized Reheat cycle Innovative Gas Turbine Combined cycle (MORITC) Power Generation System with the most effective combination of advanced technologies and the new devices have been proposed. In case of the proposed reheat cycle gas turbine with pressure ratio being 55, the high pressure turbine inlet temperature being 1700C, the low pressure turbine inlet temperature being 800C, combined with the ultra super critical pressure, double reheat type heat recovery Rankine cycle, the thermal efficiency of combined cycle are expected approximately 66.7% (LHV, generator end).


Author(s):  
Francesco Fantozzi ◽  
Bruno D’Alessandro ◽  
Pietro Bartocci ◽  
Umberto Desideri ◽  
Gianni Bidini

The Integrated Pyrolysis Regenerated Plant (IPRP) concept is based on a rotary kiln pyrolyzer that converts biomass or wastes (B&W) in a rich gas used to fuel a gas turbine (GT); the combustion of pyrolysis by-products (char or tar), is used to provide heat to the pyrolyzer together with the GT exhaust gases. The IPRP concept was modelled through an homemade software, that utilizes thermodynamic relations, energy balances and data available in the Literature for BW pyrolysis products. The analysis was carried out investigating the influence on the plant performances of main thermodynamic parameters like the Turbine Inlet Temperature (TIT), the Regeneration Ratio (RR) and the manometric compression ratio (β) of the gas turbine; when data on the pyrolysis process where available for different pyrolysis temperature, also the different pyrolysis temperature (TP) was considered. Finally, data obtained from the analysis where collected for the typical parameters of different GT sizes, namely the manometric compression ratio and the turbine inlet temperature. For the other parameters, where considered the ones that give the highest efficiencies. The paper shows the IPRP efficiency, when fuelled with different biomass or wastes materials and for different GT (plant) size.


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