Study on Neutronics and Thermalhydraulics Characteristics of 1200-MWel Pressure-Channel SuperCritical Water-Cooled Reactor (SCWR)

2014 ◽  
Author(s):  
Marija Miletic ◽  
Wargha Peiman ◽  
Amjad Farah ◽  
Jeffrey Samuel ◽  
Alexey Dragunov
Keyword(s):  
Heat Transfer ◽  
Supercritical Water ◽  
Nuclear Power ◽  
Power Plants ◽  
Thermal Power ◽  
Electrical Energy ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Accurate Estimation ◽  
Pressure Channel

Nuclear power becomes more and more important in many countries worldwide as a basis for current and future electrical-energy generation. The largest group of operating Nuclear Power Plants (NPPs) equipped with water-cooled reactors (96% of all NPPs) have gross thermal efficiencies ranging from 30% and up to 36%. Such relatively low values of thermal efficiencies are due to lower pressures/temperatures at the inlet to a turbine (4.5–7.8 MPa / 257–293°C). However, modern combined-cycle power plants (Brayton gas-turbine cycle and subcritical-pressure steam Rankine cycle, fuel – natural gas) and supercritical-pressure coal-fired power plants have reached gross thermal efficiencies of 62% and 55%, respectively. Therefore, next generation or Generation IV NPPs with water-cooled reactors should have thermal efficiencies as close as possible to those of modern thermal power plants. A significant increase in thermal efficiencies of water-cooled NPPs can be possible only due to increasing turbine inlet parameters above the critical point of water, i.e., SuperCritical Water-cooled Reactors (SCWRs) have to be designed. This path of the thermal-efficiency increasing is considered as a conventional way through which coal-fired power plants gone more than 50 years ago. Therefore, an objective of the current paper is a study on neutronics and thermalhydraulics characteristics of a generic 1200-MWel Pressure-Channel (PCh) SCWR. Standard neutronics codes DRAGON and DONJON have been coupled with a new thermalhydraulic code developed based on the latest empirical heat-transfer correlation, which allowed for more accurate estimation of basic characteristics of a PCh SCWR. In addition, the CFD Fluent code has been used for better understanding of specifics of heat transfer in supercritical water. Future studies will be dedicated to materials and fuels testing in an in-pile supercritical-water loop and developing passive-safety systems.

Study on Neutronics and Thermalhydraulics Characteristics of 1200-MWel Pressure-Channel Supercritical Water-Cooled Reactor

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Marija Miletic ◽  
Wargha Peiman ◽  
Amjad Farah ◽  
Jeffrey Samuel ◽  
Alexey Dragunov ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Supercritical Water ◽  
Nuclear Power ◽  
Power Plants ◽  
Thermal Power ◽  
Electrical Energy ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Accurate Estimation ◽  
Pressure Channel

Nuclear power becomes more and more important in many countries worldwide as a basis for current and future electrical energy generation. The largest group of operating nuclear power plants (NPPs) equipped with water-cooled reactors (96% of all NPPs) has gross thermal efficiencies ranging from 30–36%. Such relatively low values of thermal efficiencies are due to lower pressures/temperatures at the inlet to a turbine (4.5–7.8  MPa/257–293°C). However, modern combined-cycle power plants (Brayton gas-turbine cycle and subcritical-pressure steam Rankine cycle, fueled by natural gas) and supercritical-pressure coal-fired power plants have reached gross thermal efficiencies of 62% and 55%, respectively. Therefore, next generation or Generation IV NPPs with water-cooled reactors should have thermal efficiencies as close as possible to those of modern thermal power plants. A significant increase in thermal efficiencies of water-cooled NPPs can be possible only due to increasing turbine inlet parameters above the critical point of water, i.e., supercritical water-cooled reactors (SCWRs) have to be designed. This path of increasing thermal efficiency is considered as a conventional way that coal-fired power plants followed more than 50 years ago. Therefore, an objective of the current paper is a study on neutronics and thermalhydraulics characteristics of a generic 1200-MWel pressure-channel (PCh) SCWR. Standard neutronics codes DRAGON and DONJON have been coupled with a new thermalhydraulics code developed based on the latest empirical heat-transfer correlation, which allowed for more accurate estimation of basic characteristics of a PCh SCWR. In addition, the computational fluid dynamics (CFD) Fluent code has been used for better understanding of the specifics of heat transfer in supercritical water. Future studies will be dedicated to materials and fuels testing in an in-pile supercritical water loop and developing passive safety systems.

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).

Investigation of Thermal Efficiency of Generic Pressure-Channel Reactors With Steam Reheat

2016 ◽  
Author(s):  
Yifeng Zhou ◽  
Paul Ponomaryov ◽  
Cristina Mazza ◽  
Igor Pioro
Keyword(s):  
Thermal Efficiency ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Reactor ◽  
Thermal Power ◽  
Difficult Problem ◽  
Combined Cycle ◽  
The Usa ◽  
Pressure Channel ◽  
High Neutron

Currently, i.e., in 2016, 4361 nuclear-power reactors operate in the world. 96.6% of these reactors are water-cooled (373 reactors (280 PWRs, 78 BWRs and 15 LGRs are cooled with light water and 48 reactors — PHWRs are cooled with heavy water. 15% of all water-cooled reactors are pressure-channel or pressure-tube design, the rest — pressure-vessel design. All current NPPs with water-cooled reactors have relatively low thermal efficiencies within 30–36% compared to that of current NPPs with AGRs (42%) and SFR (40%) and compared to that of modern advanced thermal power plants: combined-cycle plants (up to 62%) and supercritical-pressure coal-fired plants (up to 55%). Therefore, it is very important to propose ways of improvement of thermal efficiency for this largest group of nuclear-power reactors. It should be noted that among six Generation-IV nuclear-reactor concepts one concept is a SCWR, which might reach thermal efficiencies within the range of 45–50% and even beyond. However, this concept has been never tested, and the most difficult problem on the way of implementation of this type of reactor is the reliability of materials at supercritical pressures and temperatures, very aggressive reactor coolant – supercritical water, and high neutron flux. Up till now, no experiments on behavior of various core materials at these conditions have been reported so far in the open literature. As an interim way of thermal-efficiency improvement for water-cooled NPPs nuclear steam reheat can be considered. However, this way is more appropriate only for pressure-channel reactors, for example, CANDU-type or PHWRs. Moreover, in the 60’s and 70’s, Russia, the USA and some other countries have developed and implemented the nuclear steam reheat in subcritical-pressure experimental boiling reactors. Therefore, an objective of the current paper is to summarize this experience and to estimate effect of a number of parameters on thermal efficiencies of a generic pressure-channel reactors with nuclear steam reheat. For this purpose the DE-TOP program has been used.

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.

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.

Supercritical Water-Cooled Nuclear Reactors (SCWRs): Current and Future Concepts — Steam Cycle Options

2008 ◽  
Author(s):  
R. B. Duffey ◽  
I. Pioro ◽  
X. Zhou ◽  
U. Zirn ◽  
S. Kuran ◽  
...  
Keyword(s):  
Steam Turbine ◽  
Supercritical Water ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Reactor ◽  
Hydrogen Generation ◽  
Electrical Energy ◽  
Reactor Outlet ◽  
Cycle Efficiency ◽  
Direct Cycle

One of the six Generation IV nuclear reactor concepts is a SuperCritical Water-cooled nuclear Reactor (SCWR), which is currently under development. The main objectives for developing and utilizing SCWRs are to increase the thermal efficiency of Nuclear Power Plants (NPPs), to decrease electrical energy costs, and possibility for co-generation, including hydrogen generation. Atomic Energy of Canada Limited (AECL) and Research and Development Institute of Power Engineering (RDIPE or NIKIET in Russian abbreviations) are currently developing pressure-tube SCWR concepts. The targeted steam parameters at the reactor outlet are approximately 25 MPa and 625°C. This paper presents a survey on modern SuperCritical (SC) steam turbine technology and a study on potential steam cycles for the SCWR plants. The survey reveals that by the time the Gen IV SCWRs are market-ready, the required steam turbine technology will be well proven. Three potential steam cycles in an SCWR plant are presented: a dual-cycle with steam reheat, a direct cycle with steam reheat, and a direct cycle with a Moisture Separator and Reheater (MSR). System thermal-performance simulations have been performed to determine the overall cycle efficiency of the proposed cycles. The results show that the direct cycle with steam reheat has the highest efficiency. The direct cycle with MSR is an alternative option, which will simplify the reactor design at the penalty of a slightly lower cycle efficiency.

Implicit Model Equation for Hydraulic Resistance and Heat Transfer including Wall Roughness

2016 ◽  
Vol 2 (2) ◽  
Author(s):  
Eckart Laurien
Keyword(s):  
Heat Transfer ◽  
Hydraulic Resistance ◽  
Supercritical Water ◽  
Nuclear Power ◽  
Power Plants ◽  
Supercritical Pressure ◽  
Wall Roughness ◽  
Layer Model ◽  
Two Layer Model ◽  
Analytic Prediction

Heat transfer to water at supercritical pressure within the core of a supercritical water reactor must be predicted accurately to ensure safe design of the reactor and prevent overheating of the fuel cladding. In the previous work (Laurien, 2012, “Semi-Analytic Prediction of Hydraulic Resistance and Heat Transfer for Pipe Flows of Water at Supercritical Pressure,” Proceedings of the International Conference on Advances in Nuclear Power Plants, ICAPP’12, Chicago, June 24–28), we have demonstrated that the wall shear stress and the wall temperature can be computed in a coupled way by a finite-difference method, taking the wall roughness into account. In the present paper, the classical two-layer model, consisting only of a laminar sublayer and a turbulent wall layer, is extended toward the same task. A set of implicit algebraic equations for the wall shear stress and the wall temperature is derived. It is consistent with the well-established Colebrook equation for rough pipes, which is included as a limiting case for constant properties. The accuracy of the prediction for strongly heated pipe flow is tested by comparison to experiments (Yamagata et al., 1972, “Forced Convective Heat Transfer to Supercritical Water Flowing in Tubes,” Int. J. Heat Mass Transfer, 15(12), 2575–2593) with supercritical water. The high accuracy and the generality of Laurien (2012) “Semi-Analytic Prediction of Hydraulic Resistance and Heat Transfer for Pipe Flows of Water at Supercritical Pressure,” Proceedings of the International Conference on Advances in Nuclear Power Plants, ICAPP’12, Chicago, June 24–28 are not achieved, but with the help of correction factors, the two-layer model has a potential for improved predictions of the hydraulic resistance and the heat transfer of pipe and channel flows at supercritical pressure.

Heat Transfer to Supercritical Water in Advanced Power Engineering Applications: An Industrial Scale Test Rig

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Gerrit A. Schatte ◽  
Andreas Kohlhepp ◽  
Tobias Gschnaidtner ◽  
Christoph Wieland ◽  
Hartmut Spliethoff
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Supercritical Water ◽  
Test Section ◽  
Power Plants ◽  
Thermal Power ◽  
Internal Diameter ◽  
Test Rig ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients

Heat transfer to supercritical water in heated tubes and channels is relevant for steam generators in conventional power plants and future concepts for supercritical nuclear and solar-thermal power plants. A new experimental facility, the high pressure evaporation rig, setup at the Institute for Energy Systems (Technische Universität München) aims to provide heat transfer data to fill the existing knowledge gaps at these conditions. The test rig consists of a closed-loop high pressure cycle, in which de-ionized water is fed to an instrumented test section heated by the application of direct electrical current. It is designed to withstand a maximum pressure of 380 bar at 580 °C in the test section. The maximum power rating of the system is 1 MW. The test section is a vertical tube (material: AISI A213/P91) with a 7000 mm heated length, a 15.7 mm internal diameter, and a wall thickness of 5.6 mm. It is equipped with 70 thermocouples distributed evenly along its length. It enables the determination of heat transfer coefficients in the supercritical region at various steady-state or transient conditions. In a first series of tests, experiments are conducted to investigate normal and deteriorated heat transfer (DHT) under vertical upward flow conditions. The newly generated data and literature data are used to evaluate different correlations available for modeling heat transfer coefficients at supercritical pressures.

Repowering: An Option for Refurbishment of Old Thermal Power Plants in Latin-American Countries

2010 ◽  
Author(s):  
Washington Orlando Irrazabal Bohorquez ◽  
Joa˜o Roberto Barbosa ◽  
Luiz Augusto Horta Nogueira ◽  
Electo E. Silva Lora
Keyword(s):  
Power Plant ◽  
Natural Gas ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Power Plants ◽  
Thermal Power ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Fuel Oil ◽  
Thermal Power Plants

The operational rules for the electricity markets in Latin America are changing at the same time that the electricity power plants are being subjected to stronger environmental restrictions, fierce competition and free market rules. This is forcing the conventional power plants owners to evaluate the operation of their power plants. Those thermal power plants were built between the 1960’s and the 1990’s. They are old and inefficient, therefore generating expensive electricity and polluting the environment. This study presents the repowering of thermal power plants based on the analysis of three basic concepts: the thermal configuration of the different technological solutions, the costs of the generated electricity and the environmental impact produced by the decrease of the pollutants generated during the electricity production. The case study for the present paper is an Ecuadorian 73 MWe power output steam power plant erected at the end of the 1970’s and has been operating continuously for over 30 years. Six repowering options are studied, focusing the increase of the installed capacity and thermal efficiency on the baseline case. Numerical simulations the seven thermal power plants are evaluated as follows: A. Modified Rankine cycle (73 MWe) with superheating and regeneration, one conventional boiler burning fuel oil and one old steam turbine. B. Fully-fired combined cycle (240 MWe) with two gas turbines burning natural gas, one recuperative boiler and one old steam turbine. C. Fully-fired combined cycle (235 MWe) with one gas turbine burning natural gas, one recuperative boiler and one old steam turbine. D. Fully-fired combined cycle (242 MWe) with one gas turbine burning natural gas, one recuperative boiler and one old steam turbine. The gas turbine has water injection in the combustion chamber. E. Fully-fired combined cycle (242 MWe) with one gas turbine burning natural gas, one recuperative boiler with supplementary burners and one old steam turbine. The gas turbine has steam injection in the combustion chamber. F. Hybrid combined cycle (235 MWe) with one gas turbine burning natural gas, one recuperative boiler with supplementary burners, one old steam boiler burning natural gas and one old steam turbine. G. Hybrid combined cycle (235 MWe) with one gas turbine burning diesel fuel, one recuperative boiler with supplementary burners, one old steam boiler burning fuel oil and one old steam turbine. All the repowering models show higher efficiency when compared with the Rankine cycle [2, 5]. The thermal cycle efficiency is improved from 28% to 50%. The generated electricity costs are reduced to about 50% when the old power plant is converted to a combined cycle one. When a Rankine cycle power plant burning fuel oil is modified to combined cycle burning natural gas, the CO2 specific emissions by kWh are reduced by about 40%. It is concluded that upgrading older thermal power plants is often a cost-effective method for increasing the power output, improving efficiency and reducing emissions [2, 7].

Application of Supercritical Pressures in Power Engineering

2017 ◽  
pp. 404-457
Author(s):  
Igor Pioro ◽  
Mohammed Mahdi ◽  
Roman Popov
Keyword(s):  
Heat Transfer ◽  
Carbon Dioxide ◽  
High Temperature ◽  
Gas Turbine ◽  
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).

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