Current Status and Future Applications of Supercritical Pressures in Power Engineering

2012 ◽  
Author(s):  
Anastasiia Zvorykina ◽  
Sahil Gupta ◽  
Wargha Peiman ◽  
Igor Pioro ◽  
Natalia Fialko
Keyword(s):  
Carbon Dioxide ◽  
Natural Gas ◽  
Thermal Efficiency ◽  
Nuclear Power ◽  
Power Plants ◽  
Fossil Fuels ◽  
Thermal Power ◽  
Combustion Process ◽  
Electrical Energy ◽  
Electrical Generation

It is well known that the electrical-power generation is the key factor for advances in any other industries, agriculture and level of living. In general, electrical energy can be produced by: 1) non-renewable sources such as coal, natural gas, oil, and nuclear; and 2) renewable sources such as hydro, wind, solar, biomass, geothermal and marine. However, the main sources for electrical-energy production are: 1) thermal - primary coal and secondary natural gas; 2) nuclear and 3) hydro. The rest of the sources might have visible impact just in some countries. Therefore, thermal and nuclear electrical-energy production as the major source is considered in the paper. From thermodynamics it is well known that higher thermal efficiencies correspond to higher temperatures and pressures. Therefore, modern SuperCritical (SC)-pressure coal-fired power plants have thermal efficiencies within 43–50% and even slightly above. Steam-generator outlet temperatures or steam-turbine inlet temperatures have reached a level of about 625°C (and even higher) at pressures of 25–30 (35–38) MPa. This is the largest application of SC pressures in industry. In spite of advances in coal-fired power-plants they are still considered as not environmental friendly due to producing a lot of carbon-dioxide emissions as a result of combustion process plus ash, slag and even acid rains. The most efficient modern thermal-power plants with thermal efficiencies within a range of 50–60%, are so-called, combined-cycle power plants, which use natural gas as a fuel. Natural gas is considered as a clean fossil fuel compared to coal and oil, but still due to combustion process emits a lot of carbon dioxide when it used for electrical generation. Therefore, a new reliable and environmental friendly source for the electrical-energy generation should be considered. Nuclear power is also a non-renewable source as the fossil fuels, but nuclear resources can be used for significantly longer time than some fossil fuels plus nuclear power does not emit carbon dioxide into atmosphere. Currently, this source of energy is considered as the most viable one for electrical generation for the next 50–100 years. Current, i.e., Generation II and III, Nuclear Power Plants (NPPs) consist of water-cooled reactors NPPs with the thermal efficiency of 30–35% (vast majority of reactors); subcritical carbon-dioxide-cooled reactors NPPs with the thermal efficiency up to 42% and liquid-sodium-cooled reactor NPP with the thermal efficiency of 40%. Therefore, the current fleet of NPPs, especially, water-cooled NPPs, are not very competitive compared to modern thermal power plants. Therefore, next generation or Generation-IV reactors with new parameters (NPPs with the thermal efficiency of 43–50% and even higher for all types of reactors) are currently under development worldwide. Generation-IV nuclear-reactor concept such as SuperCritical Water-cooled Reactor (SCWR) is intended to operate with direct or in-direct SC-“steam” Rankine cycle. Lead-cooled Fast Reactor (LFR) can be connected to SC-“steam” Rankine cycle or SC CO2 Brayton cycle through heat exchangers. In general, other Generation IV reactor concepts can be connected to either one or another cycle through heat exchangers. Therefore, this paper discusses various aspects of application of SC fluids in power engineering.

Power Cycles of Generation III and III+ Nuclear Power Plants

2014 ◽  
Author(s):  
Alexey Dragunov ◽  
Eugene Saltanov ◽  
Igor Pioro ◽  
Pavel Kirillov ◽  
Romney Duffey
Keyword(s):  
Renewable Energy ◽  
Natural Gas ◽  
Thermal Efficiency ◽  
Nuclear Power ◽  
Power Plants ◽  
Renewable Energy Sources ◽  
Thermal Power ◽  
Electrical Energy ◽  
Energy Sources ◽  
Thermal Power Plants

It is well known that the electrical-power generation is the key factor for advances in any other industries, agriculture and level of living. In general, electrical energy can be generated by: 1) non-renewable-energy sources such as coal, natural gas, oil, and nuclear; and 2) renewable-energy sources such as hydro, wind, solar, biomass, geothermal and marine. However, the main sources for electrical-energy generation are: 1) thermal - primary coal and secondary natural gas; 2) “large” hydro and 3) nuclear. The rest of the energy sources might have visible impact just in some countries. Modern advanced thermal power plants have reached very high thermal efficiencies (55–62%). In spite of that they are still the largest emitters of carbon dioxide into atmosphere. Due to that, reliable non-fossil-fuel energy generation, such as nuclear power, becomes more and more attractive. However, current Nuclear Power Plants (NPPs) are way behind by thermal efficiency (30–42%) compared to that of advanced thermal power plants. Therefore, it is important to consider various ways to enhance thermal efficiency of NPPs. The paper presents comparison of thermodynamic cycles and layouts of modern NPPs and discusses ways to improve their thermal efficiencies.

Power Cycles of Generation III and III+ Nuclear Power Plants

2015 ◽  
Vol 1 (2) ◽  
Author(s):  
Alexey Dragunov ◽  
Eugene Saltanov ◽  
Igor Pioro ◽  
Pavel Kirillov ◽  
Romney Duffey
Keyword(s):  
Natural Gas ◽  
Thermal Efficiency ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Thermal Power ◽  
Electrical Energy ◽  
Energy Generation ◽  
Energy Sources ◽  
Thermal Power Plants

It is well known that electrical power generation is the key factor for advances in industry, agriculture, and standard of living. In general, electrical energy can be generated by (1) nonrenewable energy sources such as coal, natural gas, oil, and nuclear; and (2) renewable energy sources such as hydro, wind, solar, biomass, geothermal, and marine. However, the main sources for electrical energy generation are (1) thermal—primarily coal and secondary natural gas, (2) “large” hydro, and (3) nuclear. Other energy sources might have a level of impact in some countries. Modern advanced thermal power plants have reached very high thermal efficiencies (55–62%). In spite of that, they are still the largest emitters of carbon dioxide into the atmosphere. Therefore, reliable non–fossil fuel energy generation, such as nuclear power, is becoming more and more attractive. However, current nuclear power plants (NPPs) are way behind in thermal efficiency (30–42%) compared to the efficiency of advanced thermal power plants. Therefore, it is important to consider various ways to enhance the thermal efficiency of NPPs. This paper presents a comparison of thermodynamic cycles and layouts of modern NPPs and discusses ways to improve their thermal efficiencies.

Advanced Gas Turbine Technology for Sendai Thermal Power Station, Unit No. 4

2011 ◽  
Author(s):  
Sadahiro Ohno ◽  
Hiroyuki Yamazaki ◽  
Naoki Hagi ◽  
Hidehiko Nishimura
Keyword(s):  
Carbon Dioxide ◽  
Natural Gas ◽  
Gas Turbine ◽  
Thermal Power Station ◽  
Thermal Efficiency ◽  
Power Plants ◽  
Thermal Power ◽  
Power Station ◽  
Advanced Technologies ◽  
Station Unit

Worldwide environmental concerns are placing center focus on effective utilization of energy and carbon dioxide emission reductions. The power generation industry has engaged in the replacement of existing aged thermal power plants with state-of-the-art natural gas fired power plants capable of achieving considerable reductions in energy consumption and emissions of green house gases. The replacement of three exiting 175MW heavy oil and coal-firing power plants with a highly effective 446MW gas-firing combined cycle power plant owned and operated by Tohoku Electric Power Company is one example of this effort. The construction of the new Sendai thermal power station, Unit No.4 started in November, 2007 achieving commercial operation in July, 2010. Mitsubishi Heavy Industries most recent 50Hz F class gas turbine upgrade, the M701F4 was adopted for this project. This engine is based on the successful M701F3 gas turbine with a 6% air flow increase and a slight bump of the turbine inlet temperature in order to achieve better thermal efficiency and more power output. The application of these advanced technologies resulted in a plant thermal efficiency of approximately 58% LHV of the new unit from the original 43% of the previous coal-firing units. The application of these advanced technologies and the use of natural gas resulted in a 2/3 carbon-dioxide emissions reduction.

Thermodynamic Considerations for a Single-Reheat Cycle SCWR

2009 ◽  
Author(s):  
M. C. Naidin ◽  
R. Monichan ◽  
U. Zirn ◽  
K. Gabriel ◽  
I. Pioro
Keyword(s):  
Thermal Efficiency ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Reactor ◽  
Thermal Power ◽  
Electrical Energy ◽  
Performance Simulation ◽  
Development Costs ◽  
And Performance ◽  
Steam Cycle

Currently, there are a number of Generation IV SuperCritical Water-cooled nuclear Reactor (SCWR) concepts under development worldwide. The main objectives for developing and utilizing SCWRs are: 1) Increase gross thermal efficiency of current Nuclear Power Plants (NPPs) from 30 – 35% to approximately 45 – 50%, and 2) Decrease capital and operational costs and, in doing so, decrease electrical-energy costs. SCW NPPs will have much higher operating parameters compared to current NPPs (i.e., steam pressures of about 25 MPa and steam outlet temperatures up to 625°C). Additionally, SCWRs will have a simplified flow circuit in which steam generators, steam dryers, steam separators, etc. will be eliminated. Furthermore, SCWRs operating at higher temperatures can facilitate an economical co-generation of hydrogen through thermo-chemical cycles (particularly, the copper-chlorine cycle) or direct high-temperature electrolysis. To decrease significantly the development costs of a SCW NPP, to increase its reliability, and to achieve similar high thermal efficiencies as the advanced fossil steam cycles it should be determined whether SCW NPPs can be designed with a steam-cycle arrangement that closely matches that of mature SuperCritical (SC) fossil-fired thermal power plants (including their SC-turbine technology). The state-of-the-art SC-steam cycles at fossil-fired power plants are designed with a single-steam reheat and regenerative feedwater heating. Due to that, they reach thermal steam-cycle efficiencies up to 54% (i.e., net plant efficiencies of up to 43% on a Higher Heating Value (HHV) Basis). This paper analyzes main parameters and performance in terms of thermal efficiency of a SCW NPP concept based on a direct regenerative steam cycle. To increase the thermal efficiency and to match current SC-turbine parameters, the cycle also includes a single steam-reheat stage. The cycle is comprised of: an SCWR, a SC turbine, which consists of one High-Pressure (HP) cylinder, one Intermediate-Pressure (IP) cylinder and two Low-Pressure (LP) cylinders, one deaerator, ten feedwater heaters, and pumps. Since this option includes a “nuclear” steam-reheat stage, the SCWR is based on a pressure-tube design. A thermal-performance simulation reveals that the overall thermal efficiency is approximately 50%.

General Layouts of Supercritical-Water NPPs

2010 ◽  
Author(s):  
I. Pioro ◽  
M. Naidin ◽  
S. Mokry ◽  
Eu. Saltanov ◽  
W. Peiman ◽  
...  
Keyword(s):  
Supercritical Water ◽  
Thermal Efficiency ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Reactor ◽  
Thermal Power ◽  
Electrical Energy ◽  
Development Costs ◽  
Flow Circuit ◽  
Steam Cycle

Currently, there are a number of Generation IV SuperCritical Water-cooled nuclear Reactor (SCWR) concepts under development worldwide. The main objectives for developing and utilizing SCWRs are: 1) Increase gross thermal efficiency of current Nuclear Power Plants (NPPs) from 30–35% to approximately 45–50%, and 2) Decrease capital and operational costs and, in doing so, decrease electrical-energy costs. SuperCritical Water (SCW) NPPs will have much higher operating parameters compared to current NPPs (i.e., steam pressures of about 25 MPa and steam outlet temperatures up to 625°C). Additionally, SCWRs will have a simplified flow circuit in which steam generators, steam dryers, steam separators, etc. will be eliminated. Furthermore, SCWRs operating at higher temperatures can facilitate an economical co-generation of hydrogen through thermo-chemical cycles (particularly, the copper-chlorine cycle) or direct high-temperature electrolysis. To decrease significantly the development costs of an SCW NPP, to increase its reliability, and to achieve similar high thermal efficiencies as the advanced fossil-fired steam cycles, it should be determined whether SCW NPPs can be designed with a steam-cycle arrangement that closely matches that of mature SuperCritical (SC) fossil-fired thermal power plants (including their SC-turbine technology). The state-of-the-art SC-steam cycles at fossil-fired power plants are designed with a single-steam reheat and regenerative feedwater heating. Due to this, they reach thermal steam-cycle efficiencies up to 54% (i.e., net plant efficiencies of up to 43–50% on a Higher Heating Value (HHV) basis). This paper presents several possible general layouts of SCW NPPs, which are based on a regenerative-steam cycle. To increase the thermal efficiency and to match current SC-turbine parameters, the cycle also includes a single steam-reheat stage. Since these options include a nuclear steam-reheat stage, the SCWR is based on a pressure-tube design.

Application of Supercritical Fluids in Thermal- and Nuclear-Power Engineering

2021 ◽  
pp. 601-658
Author(s):  
Igor L. Pioro
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
Supercritical Fluids ◽  
Nuclear Power ◽  
Power Plants ◽  
Thermal Power ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Thermal Power Plants ◽  
Power Cycles

Supercritical Fluids (SCFs) have unique thermophyscial properties and heat-transfer characteristics, which make them very attractive for use in power industry. In this chapter, specifics of thermophysical properties and heat transfer of SCFs such as water, carbon dioxide, and helium are considered and discussed. Also, particularities of heat transfer at Supercritical Pressures (SCPs) are presented, and the most accurate heat-transfer correlations are listed. Supercritical Water (SCW) is widely used as the working fluid in the SCP Rankine “steam”-turbine cycle in fossil-fuel thermal power plants. This increase in thermal efficiency is possible by application of high-temperature reactors and power cycles. Currently, six concepts of Generation-IV reactors are being developed, with coolant outlet temperatures of 500°C~1000°C. SCFs will be used as coolants (helium in GFRs and VHTRs, and SCW in SCWRs) and/or working fluids in power cycles (helium, mixture of nitrogen (80%) and helium (20%), nitrogen and carbon dioxide in Brayton gas-turbine cycles, and SCW/“steam” in Rankine cycle).

scholarly journals Controlling the Combustion Process of Thermal Power Plants to Reduce the Amount of Carbon Dioxide Produced

2016 ◽  
Vol 10 (10) ◽  
pp. 1-12
Author(s):  
Roshdy AbdelRassoul ◽  
S. IEEE ◽  
Mohamed Zaghloul ◽  
Mohamed Omar ◽  
Islam El Adly
Keyword(s):  
Carbon Dioxide ◽  
Power Plants ◽  
Thermal Power ◽  
Combustion Process ◽  
Thermal Power Plants

scholarly journals Feasibility of replacement of nuclear power with other energy sources in the Czech republic

2020 ◽  
Vol 24 (6 Part A) ◽  
pp. 3543-3553
Author(s):  
Pavel Charvat ◽  
Lubomir Klimes ◽  
Jiri Pospisil ◽  
Jiri Klemes ◽  
Petar Varbanov
Keyword(s):  
Czech Republic ◽  
Natural Gas ◽  
Nuclear Power ◽  
Power Plants ◽  
Fossil Fuels ◽  
Renewable Energy Sources ◽  
Combined Cycle ◽  
Energy Sources ◽  
The Czech Republic ◽  
The Moment

The feasibility and consequences of replacing nuclear power plants (NPP) in the Czech Republic with other energy sources are discussed. The NPP produced about one-third of electricity in the Czech Republic in 2017. Renewable energy sources such as hydropower, wind and solar power plants and biomass/biogas burning power plants produced about 11% of electricity in 2017. Due to the geographical and other constraints (intermittency, land footprint, and public acceptance), the renewables do not have the potential to entirely replace the capacity of the NPP. The only feasible technologies that could replace NPP in the Czech Republic in the near future are the power plants using fossil fuels. The combined cycle power plants running on natural gas (NGCC) are technically and environmentally fea-sible alternative for NPP at the moment. However, the natural gas imports would increase by two-thirds and the total greenhouse gas emissions would go up by about 10% if the power production of the NPP was entirely replaced by NGCC in the Czech Republic.

scholarly journals Prioritizing Energy Sources to Generate Electricity (Application of Fuzzy Logic)

2015 ◽  
Vol 10 (2) ◽  
pp. 414-421
Author(s):  
Bahareh Hashemlou ◽  
Hossein Sadeghi ◽  
Arashk Masaeli ◽  
Mohammadhadi Hajian ◽  
Shima Javaheri
Keyword(s):  
Natural Gas ◽  
Energy Demand ◽  
Power Plants ◽  
Fossil Fuels ◽  
Electrical Energy ◽  
Electricity Production ◽  
Fuzzy Preference Relations ◽  
Safety And Reliability ◽  
The Cost ◽  
Day By Day

Organizations, institutions, and different sectors of manufacturing, services and agriculture are constantly making decisions. Each of the aforementioned sectors, have strategies, tactics, and various functions that play a basic role in reaching the objectives. On the other hand, energy demand in developing countries is increasing day by day. The exact calculation of the cost per unit of electricity generated by power plants is not easy. Therefore, this study according to four sources of natural gas, nuclear energy, renewable energy and other fossil fuels other than natural gas that are used in a variety of electricity production plants is trying to clarify the ranking of generation electricity approach using "fuzzy preference relations" analysis. Accordingly, three models were used and the results showed that natural gas, with regard to the four criteria of low investment cost, low power, lack of pollution and the safety and reliability of electrical energy has priority over other alternatives. Full preferred model results also suggested that the energy of natural gas, renewable energies, nuclear and other fossil fuels should be considered in a priority for power generation. Sensitivity analysis results moreover demonstrated that the above models are not affected by the threshold values ​​and the full stability of the models is observed.

Perspective Analysis of Emerging Natural Gas-based Technology Options for Electricity Production

2019 ◽  
Vol 20 (5) ◽  
Author(s):  
Gurbakhash Bhander ◽  
Chun Wai Lee ◽  
Matthew Hakos
Keyword(s):  
Natural Gas ◽  
Carbon Capture ◽  
Power Plants ◽  
Fossil Fuels ◽  
Gas Production ◽  
Combined Cycle ◽  
Electricity Sector ◽  
Electricity Production ◽  
Low Carbon ◽  
Electrical Generation

Abstract The growing worldwide interest in low carbon electric generation technologies has renewed interest in natural gas because it is considered a cleaner burning and more flexible alternative to other fossil fuels. Recent shale gas developments have increased natural gas production and availability while lowering cost, allowing a shift to natural gas for electricity production to be a cost-effective option. Natural gas generation in the U.S. electricity sector has grown substantially in recent years (over 31 percent in 2012, up from 17 percent in 1990), while carbon dioxide (CO2) emissions of the sector have generally declined. Natural gas-fired electrical generation offers several advantages over other fossil (e. g. coal, oil) fuel-fired generation. The combination of the lower carbon-to-hydrogen ratio in natural gas (compared to other fossil fuels) and the higher efficiency of natural gas combined cycle (NGCC) power plants (using two thermodynamic cycles) than traditional fossil-fueled electric power generation (using a single cycle) results in less CO2 emissions per unit of electricity produced. Furthermore, natural gas combustion results in considerably fewer emissions of air pollutants such as nitrogen oxides (NOx), sulfur dioxide (SO2), and particulate matter (PM). Natural gas is not the main option for deep de-carbonization. If deep reduction is prioritized, whether of the electricity sector or of the entire economy, there are four primary technologies that would be assumed to play a prominent role: energy efficiency equipment, nuclear power, renewable energy, and carbon capture and storage (CCS). However, natural gas with low carbon generation technologies can be considered a “bridge” to transition to these deep decarbonization options. This paper discusses the economics and environmental impacts, focusing on greenhouse gas (GHG) emissions, associated with alternative electricity production options using natural gas as the fuel source. We also explore pairing NGCC with carbon capture, explicitly examining the costs and emissions of amine absorption, cryogenic carbon capture, carbonate fuel cells, and oxy-combustion.

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