Power Output Increase due to Decreasing Gas Turbine Inlet Temperature by Mist Atomization

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):  
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):  
Minking K. Chyu ◽  
Sin Chien Siw

The performance goal of modern gas turbine engines, both land-base and air-breathing engines, can be achieved by increasing the turbine inlet temperature (TIT). The level of TIT in the near future can reach as high as 1700 °C for utility turbines and over 1900 °C for advanced military engines. Advanced and innovative cooling techniques become one of the crucial major elements supporting the development of modern gas turbines, both land-based and air-breathing engines with continual increment of turbine inlet temperature (TIT) in order to meet higher energy demand and efficiency. This paper discusses state-of-the-art airfoil cooling techniques that are mainly applicable in the mainbody and trailing edge section of turbine airfoil. Potential internal cooling designs for near-term applications based on current manufacturing capabilities are identified. A literature survey focusing primarily on the past four to five years has also been performed.


2020 ◽  
Vol 13 (3) ◽  
pp. 215-222
Author(s):  
Akram Luaibi Ballaoot ◽  
Naseer Hamza

The gas turbine engines are occupied an important sector in the energy production and aviation industry and this important increase day after day for their features. One of the most important parameters that limit the gas turbine engine power output is the turbine inlet temperature. The higher is the turbine inlet temperature, the higher is the power output or thrust but this increases of risks of blade thermal failure due to metallurgical limits. Thus the need for a good and efficient process of blade cooling can lead to the best compromise between a powerful engine and safe operation. There are two major methods: film or external cooling and internal cooling inside the blade itself. . In the past number of years there has been considerable progress in turbine cooling research and this paper is limited to review a few selected publications to reflect recent development in turbine blade film cooling. The maximum drop in the surface temperature of the gas turbine blade and associated thermal stress – due to incorporating cooling systems- were 735 ˚C, 1217 N/mm2 respectively.


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.


Author(s):  
Tsubura Nishiyama ◽  
Masumi Iwai ◽  
Norio Nakazawa ◽  
Masafumi Sasaki ◽  
Haruo Katagiri ◽  
...  

The seven-year program, designated “Research & Development of Automotive Ceramic Gas Turbine Engine (CGT Program)”, was started in 1990 with the object of demonstrating the advantageous potentials of ceramic gas turbines for automotive use. This CGT Program is conducted by Petroleum Energy Center. The basic engine is a 100kW, single-shaft regenerative engine having turbine inlet temperature of 1350°C and rotor speed of 110000rpm. In the forth year of the program, the engine components were experimentally evaluated and improved in the various test rigs, and the first assembly test including rotating and stationary components, was performed this year under the condition of turbine inlet temperature of 1200°C.


Author(s):  
Ana C. Ferreira ◽  
Senhorinha F. Teixeira ◽  
José C. Teixeira ◽  
Manuel L. Nunes ◽  
Luís B. Martins

Energy degradation can be calculated by the quantification of entropy and loss of work and is a common approach in power plant performance analysis. Information about the location, amount and sources of system deficiencies are determined by the exergy analysis, which quantifies the exergy destruction. Micro-gas turbines are prime movers that are ideally suited for cogeneration applications due to their flexibility in providing stable and reliable power. This paper presents an exergy analysis by means of a numerical simulation of a regenerative micro-gas turbine for cogeneration applications. The main objective is to study the best configuration of each system component, considering the minimization of the system irreversibilities. Each component of the system was evaluated considering the quantitative exergy balance. Subsequently the optimization procedure was applied to the mathematical model that describes the full system. The rate of irreversibility, efficiency and flaws are highlighted for each system component and for the whole system. The effect of turbine inlet temperature change on plant exergy destruction was also evaluated. The results disclose that considerable exergy destruction occurs in the combustion chamber. Also, it was revealed that the exergy efficiency is expressively dependent on the changes of the turbine inlet temperature and increases with the latter.


Author(s):  
Mirko Baratta ◽  
Francesco Cardile ◽  
Daniela Anna Misul ◽  
Nicola Rosafio ◽  
Simone Salvadori ◽  
...  

Abstract The even more stringent limitations set by the European Commission on pollutant emissions are forcing gas turbine manufacturers towards the redesign of the most important components to increase efficiency and specific power. Current trends in gas turbine design include an increased attention to the design of cooling systems and enhanced best practices for the study of components interaction. At the same time, the recent crisis suffered by the oil and gas industry reduced the interest in brand new gas turbines, thus increasing the service market. Therefore, original equipment manufacturers would rather propose the replacement of specific components within the gas turbine plant during its maintenance with compatible elements that are likely to guarantee increased performance and longer residual lifetime at a more desirable nominal working point. In the present activity the cooling system of the TG20 heavy-duty gas turbine has been redesigned to increase the turbine inlet temperature while contemporaneously reducing the total amount of coolant mass-flow. Specifically, the cooling scheme of the rotating blade of the first turbine row has been reviewed at the Department of Energy (DENERG) of Politecnico di Torino in cooperation with EthosEnergy Italia S.p.a.. The paper presents a new design, which, starting from the original solution featuring fifteen smooth pipes, adopts an improved geometry characterized by the presence of turbulators. The activity has been carried out using Computational Fluid Dynamics (CFD) for the coolant/blade interaction and one-dimensional models developed at EthosEnergy for the redistribution of the cooling flows in the cavities. The mutual effects between the coolant fluid and the blade are analyzed using a Conjugate Heat Transfer (CHT) approach with Star-CCM+. The validation of the computational approach has been performed exploiting the experimental data available for the NASA C3X test case. The TG20 rotating blade of the first turbine row has been analyzed considering the two different coolant configurations. The impact of the main flow on the thermal field has initially been included by imposing a temperature field on the blade surface. The latter field has in turn been obtained by means of a separate computation for the solid only. Full CHT simulations has hence been performed, thus quantifying the accuracy of the proposed approach. The obtained results are discussed in terms of thermo-fluid-dynamic effects.


Author(s):  
Hideto Moritsuka ◽  
Tomoharu Fujii ◽  
Takeshi Takahashi

The thermal efficiency of gas turbine combined cycle power generation plants increase significantly in accordance with turbine inlet temperature. Gas turbine combined cycle power plants operating at high turbine inlet temperature are popular as a main thermal power station among our electric power companies in Japan. Thus, gas turbine hot gas parts are working under extreme conditions which will strongly affect their lifetime as well as maintenance costs for repaired and replaced parts. To reduce the latter is of major importance to enhance cost effectiveness of the plant. This report describes a gas turbine maintenance management program of main hot gas parts (combustor chambers, transition peices, turbine 1st. stage nozzles and 1st. stage buckets) for management persons of gas turbine combined cycle power stations in order to obtain an optimal gas turbine maintenance schedule considering rotation, repair and replacement or exchange of those parts.


2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Chao Deng ◽  
Ahmed N. Abdalla ◽  
Thamir K. Ibrahim ◽  
MingXin Jiang ◽  
Ahmed T. Al-Sammarraie ◽  
...  

In this article, the adaptive neuro-fuzzy inference system (ANFIS) and multiconfiguration gas-turbines are used to predict the optimal gas-turbine operating parameters. The principle formulations of gas-turbine configurations with various operating conditions are introduced in detail. The effects of different parameters have been analyzed to select the optimum gas-turbine configuration. The adopted ANFIS model has five inputs, namely, isentropic turbine efficiency (Teff), isentropic compressor efficiency (Ceff), ambient temperature (T1), pressure ratio (rp), and turbine inlet temperature (TIT), as well as three outputs, fuel consumption, power output, and thermal efficiency. Both actual reported information, from Baiji Gas-Turbines of Iraq, and simulated data were utilized with the ANFIS model. The results show that, at an isentropic compressor efficiency of 100% and turbine inlet temperature of 1900 K, the peak thermal efficiency amounts to 63% and 375 MW of power resulted, which was the peak value of the power output. Furthermore, at an isentropic compressor efficiency of 100% and a pressure ratio of 30, a peak specific fuel consumption amount of 0.033 kg/kWh was obtained. The predicted results reveal that the proposed model determines the operating conditions that strongly influence the performance of the gas-turbine. In addition, the predicted results of the simulated regenerative gas-turbine (RGT) and ANFIS model were satisfactory compared to that of the foregoing Baiji Gas-Turbines.


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