scholarly journals Modeling of advanced fossil fuel power plants

2021 ◽  
Author(s):  
Farshid Zabihian
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Power Plants ◽  
Fossil Fuel ◽  
Specific Power ◽  
Operating Pressure ◽  
Utilization Factor ◽  
Fuel Switching ◽  
Wide Range ◽  
Cycle Efficiency

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.

scholarly journals Modeling of advanced fossil fuel power plants

2021 ◽  
Author(s):  
Farshid Zabihian
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Power Plants ◽  
Fossil Fuel ◽  
Specific Power ◽  
Operating Pressure ◽  
Utilization Factor ◽  
Fuel Switching ◽  
Wide Range ◽  
Cycle Efficiency

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.

Gas Turbine With Constant Volume Heat Addition

2010 ◽  
Author(s):  
S. Can Gu¨len
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Power Plants ◽  
Fossil Fuel ◽  
Combined Cycle ◽  
Brayton Cycle ◽  
Heat Addition ◽  
Volume Heat

Increasing the thermal efficiency of fossil fuel fired power plants in general and the gas turbine power plant in particular is of extreme importance. In the face of diminishing natural resources and increasing carbon emissions that lead to a heightened greenhouse effect and greater concerns over global warming, thermal efficiency is more critical today than ever before. In the science of thermodynamics, the best yardstick for a power generation system’s performance is the Carnot efficiency — the ultimate efficiency limit, set by the second law, which can be achieved only by a perfect heat engine operating in a cycle. As a fact of nature this upper theoretical limit is out of reach, thus engineers usually set their eyes on more realistic goals. For the longest time, the key performance benchmark of a combined cycle (CC) power plant has been the 60% net electric efficiency. Land-based gas turbines based on the classic Brayton cycle with constant pressure heat addition represent the pinnacle of fossil fuel burning power generation engineering. Advances in the last few decades, mainly driven by the increase in cycle maximum temperatures, which in turn are made possible by technology breakthroughs in hot gas path materials, coating and cooling technologies, pushed the power plant efficiencies to nearly 40% in simple cycle and nearly 60% in combined cycle configurations. To surpass the limitations imposed by available materials and other design considerations and to facilitate a significant improvement in the thermal efficiency of advanced Brayton cycle gas turbine power plants necessitate a rethinking of the basic thermodynamic cycle. The current paper highlights the key thermodynamic considerations that make the constant volume heat addition a viable candidate in this respect. First using fundamental air-standard cycle formulas and then more realistic but simple models, potential efficiency improvement in simple and combined cycle configurations is investigated. Existing and past research activities are summarized to illustrate the technologies that can transform the basic thermodynamics into a reality via mechanically and economically feasible products.

Parametric Analysis of Combined Cycles Equipped With Inlet Fogging

2006 ◽  
Vol 128 (2) ◽  
pp. 326-335 ◽  
Author(s):  
R. Bhargava ◽  
M. Bianchi ◽  
F. Melino ◽  
A. Peretto
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Advanced Technology ◽  
Fuel Prices ◽  
Power Enhancement ◽  
Wide Range ◽  
Combined Cycles

In recent years, deregulation in the power generation market worldwide combined with significant variation in fuel prices and a need for flexibility in terms of power augmentation specially during periods of high electricity demand (summer months or noon to 6:00 p.m.) has forced electric utilities, cogenerators and independent power producers to explore new power generation enhancement technologies. In the last five to ten years, inlet fogging approach has shown more promising results to recover lost power output due to increased ambient temperature compared to the other available power enhancement techniques. This paper presents the first systematic study on the effects of both inlet evaporative and overspray fogging on a wide range of combined cycle power plants utilizing gas turbines available from the major gas turbine manufacturers worldwide. A brief discussion on the thermodynamic considerations of inlet and overspray fogging including the effect of droplet dimension is also presented. Based on the analyzed systems, the results show that high pressure inlet fogging influences performance of a combined cycle power plant using an aero-derivative gas turbine differently than with an advanced technology or a traditional gas turbine. Possible reasons for the observed differences are discussed.

Parametric Analysis of Combined Cycles Equipped With Inlet Fogging

2003 ◽  
Author(s):  
R. Bhargava ◽  
M. Bianchi ◽  
F. Melino ◽  
A. Peretto
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Advanced Technology ◽  
Fuel Prices ◽  
Power Enhancement ◽  
Wide Range ◽  
Combined Cycles

In recent years, deregulation in the power generation market worldwide combined with significant variation in fuel prices and a need for flexibility in terms of power augmentation specially during periods of high electricity demand (summer months or noon to 6 PM) has forced electric utilities, cogenerators and independent power producers to explore new power generation enhancement technologies. In the last 5–10 years, inlet fogging approach has shown more promising results to recover lost power output due to increased ambient temperature compared to the other available power enhancement techniques. This paper presents the first systematic study on the effects of both inlet evaporative and overspray fogging on a wide range of combined cycle power plants utilizing gas turbines available from the major gas turbine manufacturers worldwide. A brief discussion on the thermodynamic considerations of inlet and overspray fogging including the effect of droplet dimension is also presented. Based on the analyzed systems, the results show that high pressure inlet fogging influences performance of a combined cycle power plant using an aero-derivative gas turbine differently than with an advanced technology or a traditional gas turbine. Possible reasons for the observed differences are discussed.

Natural Gas Decarbonization to Reduce CO2 Emission From Combined Cycles—Part II: Steam-Methane Reforming

2000 ◽  
Vol 124 (1) ◽  
pp. 89-95 ◽  
Author(s):  
G. Lozza ◽  
P. Chiesa
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Partial Oxidation ◽  
Power Plants ◽  
Combined Cycle ◽  
Performance Estimation ◽  
Thermodynamic Efficiency ◽  
Methane Reforming ◽  
Operating Pressure ◽  
Carbon Conversion

This paper discusses novel schemes of combined cycle, where natural gas is chemically treated to remove carbon, rather than being directly used as fuel. Carbon conversion to CO2 is achieved before gas turbine combustion. The first part of the paper discussed plant configurations based on natural gas partial oxidation to produce carbon monoxide, converted to carbon dioxide by shift reaction and therefore separated from the fuel gas. The second part will address methane reforming as a starting reaction to achieve the same goal. Plant configuration and performance differs from the previous case because reforming is endothermic and requires high temperature heat and low operating pressure to obtain an elevated carbon conversion. The performance estimation shows that the reformer configuration has a lower efficiency and power output than the systems addressed in Part I. To improve the results, a reheat gas turbine can be used, with different characteristics from commercial machines. The thermodynamic efficiency of the systems of the two papers is compared by an exergetic analysis. The economic performance of natural gas fired power plants including CO2 sequestration is therefore addressed, finding a superiority of the partial oxidation system with chemical absorption. The additional cost of the kWh, due to the ability of CO2 capturing, can be estimated at about 13–14 mill$/kWh.

scholarly journals Thermodynamic Analysis of Different Configurations of Combined Cycle Power Plants

2015 ◽  
Vol 5 (2) ◽  
pp. 89
Author(s):  
Munzer S. Y. Ebaid ◽  
Qusai Z. Al-hamdan
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Combined Cycle ◽  
Cycle Performance ◽  
Maximum Efficiency ◽  
Specific Work ◽  
Slight Effect ◽  
Turbine Engine ◽  
Gas Turbine Cycle ◽  
Cycle Efficiency

<p class="1Body">Several modifications have been made to the simple gas turbine cycle in order to increase its thermal efficiency but within the thermal and mechanical stress constrain, the efficiency still ranges between 38 and 42%. The concept of using combined cycle power or CPP plant would be more attractive in hot countries than the combined heat and power or CHP plant. The current work deals with the performance of different configurations of the gas turbine engine operating as a part of the combined cycle power plant. The results showed that the maximum CPP cycle efficiency would be at a point for which the gas turbine cycle would have neither its maximum efficiency nor its maximum specific work output. It has been shown that supplementary heating or gas turbine reheating would decrease the CPP cycle efficiency; hence, it could only be justified at low gas turbine inlet temperatures. Also it has been shown that although gas turbine intercooling would enhance the performance of the gas turbine cycle, it would have only a slight effect on the CPP cycle performance.</p>

scholarly journals Coal Mine Methane Utilization in Gas Turbine Units for Electricity and Heat Production

2015 ◽  
Vol 4 (5) ◽  
pp. 41-48 ◽  
Author(s):  
Кулаков ◽  
D. Kulakov ◽  
Щёголев ◽  
N. Shchegolev ◽  
Тумашев ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Coal Mining ◽  
Coal Mine ◽  
Power Plants ◽  
Negative Impact ◽  
Inlet Temperature ◽  
Ecological Situation ◽  
Modern Approach ◽  
Coal Mine Methane ◽  
Wide Range

Coal mining is accompanied by the release of coal mine methane. Its emissions into the atmosphere within methane-air mixture have a negative impact on the ecological situation. The modern approach involves the use of methane-air-mixture for heat boilers or units to generate electricity. For the generation of heat and electrical energy the coal mine methane could be used in cogeneration gas turbine plants with an altered sequence of processes. Thermo — and gas dynamics studies were conducted in a wide range of parameters of gas turbine plants. For small power plants recommended are: 2.8 compression ratio, turbine inlet — 1173 K, gas cooler inlet temperature — 303 K, 0.8 regeneration ratio. In this case the electrical efficiency of gas turbine plant is 25–26% and even 63–64% if produced heat is counted. Cogeneration gas turbine plant with an altered sequence of process has smaller capital and operating costs compared to traditional gas turbine unit. The use of methane-air mixture as fuel in such gas turbine units increases the profitability of coal mining and improves the ecological situation in the region.

Preliminary Study on Combustion of Biodiesel for Power Generation

2006 ◽  
Author(s):  
Ee Sann Tan ◽  
Kumaran Palanisamy ◽  
Ibrahim Hussein ◽  
Farid Nasir Ani
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Fossil Fuel ◽  
Alternative Fuel ◽  
Waste Cooking Oil ◽  
Combustion Efficiency ◽  
Test Facility ◽  
Animal Fats ◽  
Cooking Oil ◽  
Crude Oil Prices

In the recent wake of escalating crude oil prices due to depletion of fossil fuel, biodiesel has generated a significant interest as an alternative fuel for the future. The use of biodiesel to fuel microturbines or gas turbine application is envisaged to solve problems of diminishing supplies of fossil fuel reserves and environmental concerns. This paper examines the combustion of biodiesel derived from Malaysian Waste Cooking Oil (WCO) in a combustion test facility to study the feasibility of using the designated fuel at five various volumetric ratios for gas turbine application. Biodiesel was produced from waste cooking oil in Malaysia, mainly from palm oil sources and animal fats. The oil burner was able to fire the five blends of fuel without any modification or pretreatment. The combustion performance of Malaysian WCO biodiesel and distillate blends was examined with respect to the combustion efficiency. The results indicated biodiesel combustion required less air for stoichiometric combustion due to presence of oxygen in the fuel. Indeed biodiesel stand as a potential alternative fuel for power generation application with the best efficiency at blended ratio of 20% biodiesel and 80% distillate.

Operation Experiences of Siemens IGCC Gas Turbines Using Gasification Products From Coal and Refinery Residues

2000 ◽  
Author(s):  
M. Huth ◽  
A. Heilos ◽  
G. Gaio ◽  
J. Karg
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Strong Impact ◽  
Coal Gas ◽  
Operation Conditions ◽  
Wide Range ◽  
Commercial Operation ◽  
Burner Design

The Integrated Gasification Combined Cycle concept is an emerging technology that enables an efficient and clean use of coal as well as residuals in power generation. After several years of development and demonstration operation, now the technology has reached the status for commercial operation. SIEMENS is engaged in 3 IGCC plants in Europe which are currently in operation. Each of these plants has specific characteristics leading to a wide range of experiences in development and operation of IGCC gas turbines fired with low to medium LHV syngases. The worlds first IGCC plant of commercial size at Buggenum/Netherlands (Demkolec) has already demonstrated that IGCC is a very efficient power generation technology for a great variety of coals and with a great potential for future commercial market penetration. The end of the demonstration period of the Buggenum IGCC plant and the start of its commercial operation has been dated on January 1, 1998. After optimisations during the demonstration period the gas turbine is running with good performance and high availability and has exceeded 18000 hours of operation on coal gas. The air-side fully integrated Buggenum plant, equipped with a Siemens V94.2 gas turbine, has been the first field test for the Siemens syngas combustion concept, which enables operation with very low NOx emission levels between 120–600 g/MWh NOx corresponding to 6–30 ppm(v) (15%O2) and less than 5 ppm(v) CO at baseload. During early commissioning the syngas nozzle has been recognised as the most important part with strong impact on combustion behaviour. Consequently the burner design has been adjusted to enable quick and easy changes of the important syngas nozzle. This design feature enables fast and efficient optimisations of the combustion performance and the possibility for easy adjustments to different syngases with a large variation in composition and LHV. During several test runs the gas turbine proved the required degree of flexibility and the capability to handle transient operation conditions during emergency cases. The fully air-side integrated IGCC plant at Puertollano/Spain (Elcogas), using the advanced Siemens V94.3 gas turbine (enhanced efficiency), is now running successfully on coal gas. The coal gas composition at this plant is similar to the Buggenum example. The emission performance is comparable to Buggenum with its very low emission levels. Currently the gas turbine is running for the requirements of final optimization runs of the gasifier unit. The third IGCC plant (ISAB) equipped with Siemens gas turbine technology is located at Priolo near Siracusa at Sicilly/Italy. Two Siemens V94.2K (modified compressor) gas turbines are part of this “air side non-integrated” IGCC plant. The feedstock of the gasification process is a refinery residue (asphalt). The LHV is almost twice compared to the Buggenum or Puertollano case. For operation with this gas, the coal gas burner design was adjusted and extensively tested. IGCC operation without air extraction has been made possible by modifying the compressor, giving enhanced surge margins. Commissioning on syngas for the first of the two gas turbines started in mid of August 1999 and was almost finished at the end of August 1999. The second machine followed at the end of October 1999. Since this both machines are released for operation on syngas up to baseload.

Advanced Control for Clusters of SOFC/Gas Turbine Hybrid Systems

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Iacopo Rossi ◽  
Valentina Zaccaria ◽  
Alberto Traverso
Keyword(s):  
Fuel Cell ◽  
Power Systems ◽  
Gas Turbine ◽  
Power Plants ◽  
Numerical Approach ◽  
Computational Time ◽  
Target System ◽  
Wide Range ◽  
Advanced Control ◽  
Complex Target

The use of model predictive control (MPC) in advanced power systems can be advantageous in controlling highly coupled variables and optimizing system operations. Solid oxide fuel cell/gas turbine (SOFC/GT) hybrids are an example where advanced control techniques can be effectively applied. For example, to manage load distribution among several identical generation units characterized by different temperature distributions due to different degradation paths of the fuel cell stacks. When implementing an MPC, a critical aspect is the trade-off between model accuracy and simplicity, the latter related to a fast computational time. In this work, a hybrid physical and numerical approach was used to reduce the number of states necessary to describe such complex target system. The reduced number of states in the model and the simple framework allow real-time performance and potential extension to a wide range of power plants for industrial application, at the expense of accuracy losses, discussed in the paper.

Sign in / Sign up

Export Citation Format

Share Document