Coatings for Advanced Large Frame Combustion Turbines for Power Generation

Author(s):  
R. Viswanathan ◽  
N. S. Cheruvu ◽  
K. S. Chan

Use of metallic coatings for protecting hot section blades and vanes of combustion turbines for power generation has been a common practice for the last three decades. Since these coatings have to be optimized both with respect to different forms of corrosion and operation (base load vs. peak load) their performance can be machine specific. Power company users generally do not have sufficient knowledge of the failure mechanisms of the coatings and the basis for selecting coatings to suit their specific requirements. This paper describes the evolution of metallic coatings, discusses failure mechanisms, and describes a methodology for comparing and selecting machine-specific coatings. The methodology, which can be used to rank and predict the remaining life of coatings and for optimizing operation, forms the basis of a computer code known as COATLIFE. The ingredients of this methodology, i.e., degradation modeling and thermomechanical fatigue life (TMF) prediction, are reviewed in the paper.

2020 ◽  
Vol 10 (21) ◽  
pp. 7822
Author(s):  
Sang Hun Lee ◽  
Wonbin Lee ◽  
Jin Hee Hyun ◽  
Byeong Gwan Bhang ◽  
Jinho Choi ◽  
...  

In this paper, a design technique for constructing a renewable-energy-based power system based on a customer’s power load is proposed. The proposed design technique adopts a second renewable energy power source in charge of the base load and is an improved method of the referenced studies with one type of renewable energy power source. In this proposed method, fuel cells are adopted as the base power source, and PV (photovoltaic) power generation and an ESS (energy storage system) are adopted as the power generation sources that supply the middle-load and peak-load power. When the fuel cell is applied as a base power source through the method designed in this study, a cost reduction of approximately 30.03% is expected, compared to a system that does not use a base power source. In addition, the criteria for securing a system’s power supply stability and the economics when fuel cells are adopted are analyzed in terms of the system’s installation cost.


Author(s):  
Sooyong Kim ◽  
Sungryong Lee ◽  
Jewook Ryu ◽  
V. E. Spitsyn

Gas turbine engine has been applied to the aircraft and ship propulsion with its advantages of compactness and comparatively short starting time. With a significant improvement in gas turbine efficiency with development of super alloy materials and advancement in cooling technologies in the second half of 1990s, its importance as a source of base load as well as peak load power generation has been increasing. However, with increased demand in nuclear power and renewable energy in the 21st century, there seems to be speculations among the power generation industries that gas turbine will take more or less a buffering role supplementing the irregular inflow of electricity to the grid rather than acting as a base load power source. With the shift in the role of gas turbine from base to supplementary, CHP application based on small powered gas turbine utilizing biogas or syngas as its fuel is expected to increase in the future. In this context, this paper describes the development result of 5MW gas turbine engine for CHP application. It can be operated with LNG or syngas of low LHV fuel. Originally, the engine was designed for LNG as its primary fuel, but since the importance of syngas power generation market will be increasing in the future, a complementary work for modification of combustor part has been carried out and has been tested. However, this paper deals with the parts developed with the use of LNG fuel. The test result of emission characteristics meets the standards required in Korea. The development has been made through the cooperation of Doosan Heavy Industry (DHI, Korea) and Zory-Mashproekt (Ukraine).


2010 ◽  
Vol 27 (02) ◽  
pp. 271-286 ◽  
Author(s):  
RYUTA TAKASHIMA ◽  
MAKOTO GOTO ◽  
MOTOH TSUJIMURA

We consider an optimal investment problem when a firm such as an electric power company has the operational flexibility to expand and contract capacity with fixed cost. This problem is formulated as an impulse control problem combined with optimal stopping. Consequently, we obtain optimal investment timing, optimal capacity expansion and contraction timing, and the investment value. We also show investment, capacity expansion and contraction rule are influenced by the price volatility and the initial capacity is also influenced by the ratio between base-load plant and peak-load plant. In addition, we investigate how time lag between investment and operation influences the investment rule.


2013 ◽  
Vol 684 ◽  
pp. 680-685 ◽  
Author(s):  
Md. Shahinur Islam ◽  
Tausif Ali ◽  
Ahsan Uddin Ahmed ◽  
Syed Ashraful Karim ◽  
Hossain Mursalin

World climate change challenges and the world’s consistent growing demand for energy during the past decade have brought the need to explore for more renewable energy resources. The continuation of exploring green energy sources results Osmotic Power- a new emission-free source of sustainable energy that can be used to generate electricity. Osmotic power plant is only feasible in places where rivers flow out to the ocean. The leading virtue of osmotic power is that it would be capable to produce a steady and reliable supply of renewable base load power as an alternative of other variable sources like solar or wind. There are some hurdles to generate osmotic power. Developing suitable membrane and initial construction cost are top on of them. Though Osmotic power is years from commercial feasibility but researchers think that it could provide thousands of terawatts of base load power per year around the globe. This paper presents an overview of osmotic power generation system with the analysis of potential benefits and limitations of it.


2021 ◽  
Vol 124 ◽  
pp. 105301
Author(s):  
Benyamin Piri ◽  
Rasool Amini ◽  
Erfan Asadinia ◽  
Shirin Vardak ◽  
Reza Mehdilouee ◽  
...  

Author(s):  
Charles Forsberg

A combined-cycle power plant is proposed that uses heat from a high-temperature nuclear reactor and hydrogen produced by the high-temperature reactor to meet base-load and peak-load electrical demands. For base-load electricity production, air is compressed; flows through a heat exchanger, where it is heated to between 700 and 900°C; and exits through a high-temperature gas turbine to produce electricity. The heat, via an intermediate heat-transport loop, is provided by a high-temperature reactor. The hot exhaust from the Brayton-cycle turbine is then fed to a heat recovery steam generator that provides steam to a steam turbine for added electrical power production. To meet peak electricity demand, after nuclear heating of the compressed air, hydrogen is injected into the combustion chamber, combusts, and heats the air to 1300°C—the operating conditions for a standard natural-gas-fired combined-cycle plant. This process increases the plant efficiency and power output. Hydrogen is produced at night by electrolysis or other methods using energy from the nuclear reactor and is stored until needed. Therefore, the electricity output to the electric grid can vary from zero (i.e., when hydrogen is being produced) to the maximum peak power while the nuclear reactor operates at constant load. Because nuclear heat raises air temperatures above the auto-ignition temperatures of the hydrogen and powers the air compressor, the power output can be varied rapidly (compared with the capabilities of fossil-fired turbines) to meet spinning reserve requirements and stabilize the grid.


Author(s):  
Wolfgang Kappis ◽  
Stefan Florjancic ◽  
Uwe Ruedel

Market requirements for the heavy duty gas turbine power generation business have significantly changed over the last few years. With high gas prices in former times, all users have been mainly focusing on efficiency in addition to overall life cycle costs. Today individual countries see different requirements, which is easily explainable picking three typical trends. In the United States, with the exploitation of shale gas, gas prices are at a very low level. Hence, many gas turbines are used as base load engines, i.e. nearly constant loads for extended times. For these engines reliability is of main importance and efficiency somewhat less. In Japan gas prices are extremely high, and therefore the need for efficiency is significantly higher. Due to the challenge to partly replace nuclear plants, these engines as well are mainly intended for base load operation. In Europe, with the mid and long term carbon reduction strategy, heavy duty gas turbines is mainly used to compensate for intermittent renewable power generation. As a consequence, very high cyclic operation including fast and reliable start-up, very high loading gradients, including frequency response, and extended minimum and maximum operating ranges are required. Additionally, there are other features that are frequently requested. Fuel flexibility is a major demand, reaching from fuels of lower purity, i.e. with higher carbon (C2+), content up to possible combustion of gases generated by electrolysis (H2). Lifecycle optimization, as another important request, relies on new technologies for reconditioning, lifetime monitoring, and improved lifetime prediction methods. Out of Alstom’s recent research and development activities the following items are specifically addressed in this paper. Thermodynamic engine modelling and associated tasks are discussed, as well as the improvement and introduction of new operating concepts. Furthermore extended applications of design methodologies are shown. An additional focus is set ono improve emission behaviour understanding and increased fuel flexibility. Finally, some applications of the new technologies in Alstom products are given, indicating the focus on market requirements and customer care.


2013 ◽  
Vol 772 ◽  
pp. 705-710
Author(s):  
Li Wei Ju ◽  
Zhong Fu Tan ◽  
He Yin ◽  
Zhi Hong Chen

In order to be able to absorb the abandoned wind, increasing wind-connect amount, the paper study the way of wind power, thermal power joint run and puts forward wind power, thermal power joint run optimization model based on the energy-saving generation dispatching way under the environment of TOU price and the target of minimizing the cost of coal-fired cost, unit commitment and pollution emissions. The numerical example finds, the TOU price can realize the goal of peak load shifting, increasing the electricity demand in the low load and reducing electricity demand in the peak load. The model can increase the amount of wind-connect grid, absorb the abandoned wind, reduce the use of coal-fired units under the environment, increase the average electricity sales price and profit of Power Company. Therefore, the model has significant economical environmental benefits


2021 ◽  
Author(s):  
Farshid Zabihian

The first part of this thesis deals with greenhouse gas (GHG) emissions from fossil fuel-fired power stations. The GHG emission estimation from fossil fuel power generation industry signifies that emissions from this industry can be significantly reduced by fuel switching and adaption of advanced power generation technologies. In the second part of the thesis, steady-state models of some of the advanced fossil fuel power generation technologies are presented. The impacts of various parameters on the solid oxide fuel cell (SOFC) overpotentials and outputs are investigated. The detail analyses of operation of the hybrid SOFC-gas turbine (GT) cycle when fuelled with methane and syngas demonstrate that the efficiencies of the cycles with and without anode exhaust recirculation are close, but the specific power of the former is much higher. The parametric analysis of the performance of the hybrid SOFC-GT cycle indicates that increasing the system operating pressure and SOFC operating temperature and fuel utilization factor improves cycle efficiency, but the effects of the increasing SOFC current density and turbine inlet temperature are not favourable. The analysis of the operation of the system when fuelled with a wide range of fuel types demonstrates that the hybrid SOFC-GT cycle efficiency can be between 59% and 75%, depending on the inlet fuel type. Then, the system performance is investigated when methane as a reference fuel is replaced with various species that can be found in the fuel, i.e., H₂, CO₂, CO, and N₂. The results point out that influence of various species can be significant and different for each case. The experimental and numerical analyses of a biodiesel fuelled micro gas turbine indicate that fuel switching from petrodiesel to biodiesel can influence operational parameters of the system. The modeling results of gas turbine-based power plants signify that relatively simple models can predict plant performance with acceptable accuracy. The unique feature of these models is that they are developed based on similar assumptions and run at similar conditions; therefore, their results can be compared. This work demonstrates that, although utilization of fossil fuels for power generation is inevitable, at least in the short- and mid-term future, it is possible and practical to carry out such utilization more efficiently and in an environmentally friendlier manner.


Author(s):  
Xinli Lu ◽  
Arnold Watson ◽  
Joe Deans

Since the first geothermal power plant was built at Larderello (Italy) in 1904, many attempts have been made to improve conversion efficiency. Among innovative technologies, using the Kalina cycle is considered as one of the most effective means of enhancing the thermodynamic performance for both high and low temperature heat source systems. Although initially used as the bottoming cycle of gas turbines and diesel engines, in the late 1980s the Kalina cycle was found to be attractive for geothermal power generation [1, 2, 3]. Different versions (KSC11, KSC12 and KSC13) were designated. Comparison between Kalina cycle and other power cycles can be found in later studies [4, 5, 6]. Here we examine KSC11, because it is specifically designed for geothermal power generation, with lower capital cost [3]. We compare this design with the existing Kawerau ORMAT binary plant in New Zealand. In addition, parametric sensitivity analysis of KCS11 has been carried out for the specific power output and net thermal efficiency by changing the temperatures of both heat source and heat sink for a given ammonia-water composition.


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