SuperCritical-Water Reactor NPP Concept: No-Reheat Cycle Option

2009 ◽  
Author(s):  
M. C. Naidin ◽  
I. Pioro ◽  
U. Zirn ◽  
K. Chophla
Keyword(s):  
Thermal Efficiency ◽  
Power Plants ◽  
Thermal Power ◽  
Electricity Production ◽  
Pump Efficiency ◽  
Thermal Power Plants ◽  
Fluid Temperature ◽  
Bulk Fluid ◽  
Research Activities ◽  
Lp Turbine

Research activities are currently conducted worldwide to develop Generation IV nuclear reactor concepts with the objective of improving thermal efficiency and increasing economic competitiveness of Generation IV Nuclear Power Plants (NPPs) compared to modern thermal power plants. The Super-Critical Water-cooled Reactor (SCWR) concept is one of the six Generation IV options chosen for further investigation and development in several countries including Canada and Russia. Water-cooled reactors operating at subcritical pressures (10 – 16 MPa) have provided a significant amount of electricity production for the past 50 years. However, the thermal efficiency of the current NPPs is not very high (30–35%). As such, more competitive designs, with higher thermal efficiencies, which will be close to that of modern thermal power plants (45 – 50%), need to be developed and implemented. Previous studies have shown that direct cycles, with no-reheat and single-reheat configurations are the best choice for the SCWR concept. However, the single-reheat cycle requires a nuclear steam-reheat, thus increasing the complexity of the reactor core design. Although preliminary results show that the thermal efficiency of the no-reheat cycle is approximately 2% lower than that of the single-reheat cycle, the less complex core configuration may prove to be a major factor when selecting the most suitable design. This paper investigates the main parameters and performance in terms of thermal efficiency of a SCW NPP based on a no-reheat, direct cycle with heat regeneration. When compared to the single-reheat cycle, the no-reheat configuration has a more simplified design: the Intermediate-Pressure (IP) turbine section is eliminated and the exhaust from the High-Pressure (HP) turbine is directly routed to the inlet of the Low-Pressure (LP) turbines. The cycle also consists of a condenser, nine feedwater heaters, a topping de-superheater, associated pumps, and the nuclear source of energy, i.e., the SCWR. In general, the major technical challenge associated with a SC no-reheat turbine is the high moisture content in the LP turbine exhaust. A thermal-performance simulation reveals that the steam quality at the exhaust from the LP turbine is approximately 81%. However, the moisture can be reduced by implementation of contoured channels in the inner casing for draining water and moisture removal stages. The overall thermal efficiency of the cycle was determined to be about 50% (assumptions are made to account for turbine and pump efficiency losses). Furthermore, important safety parameters such as bulk-fluid temperature, sheath temperature and fuel-centerline temperature are calculated for a non-uniform cosine Axial Heat Flux Profile (AHFP) along a generic fuel channel of the no-reheat SCWR concept.

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.

scholarly journals Functional Features of National Thermal Power Plantsunder Sustainable Development Conditions

2018 ◽  
Keyword(s):  
Sustainable Development ◽  
Electricity Generation ◽  
Power Plants ◽  
Thermal Power ◽  
Market Model ◽  
Electricity Production ◽  
Thermal Power Plants ◽  
The Sustainable Development ◽  
Energy Independence ◽  
Functional Features

The paper is devoted to analysis of functional peculiarities of thermal power plants in Ukraine. In the course of the study, key determinants of the sustainable development of domestic electricity generation were identified in the context of transition to a new market model. The preconditions of activation and support of the sustainable development concept implementation process in the modern business practice of the energy sector enterprises within the Ukrainian economy are outlined. The theoretical and practical bases for ensuring the sustainable development of energy in relation to other United Nations Declarations of Sustainable Development are indicated. The comparative estimation of the efficiency level of state policy in scope of energy independence and resource conservation with the use of a complex indicator of GDP energy intensity is given. On the basis of international and domestic statistical data the dynamics of volumes of electricity production in Ukraine for the period of 1990-2017 as well as the structure of electricity generation by type of generation were analyzed. The dynamics of electric power generation in Ukraine by types of raw materials was presented in complex with the dynamics of coal consumption and production for the corresponding period. The peculiarities of thermal power plants functioning in comparison with other power generating enterprises in modern conditions are specified. The key element of Ukraine’s energy independence – the volume of proven coal reserves – is a prerequisite for the efficient functioning of domestic thermal power plants. The pricing features in the sphere of electricity production and sales are outlined, in particular, the structure of market rate and the price of electricity sales by producers to the Wholesale Market are presented. The significance of the innovation factor in the process of improving the efficiency of thermal power plants functioning has been substantiated, taking into account the economic, social and environmental aspects of their production and economic activity.

scholarly journals Structural and Parametric Optimization of S-CO2 Thermal Power Plants with a Pulverized Coal-Fired Boiler Operating in Russia

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7136
Author(s):  
Andrey Rogalev ◽  
Vladimir Kindra ◽  
Ivan Komarov ◽  
Sergey Osipov ◽  
Olga Zlyvko
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
Rankine Cycle ◽  
Combustion Products ◽  
Pulverized Coal ◽  
Electricity Production ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Thermal Power Plants ◽  
Increase Energy Efficiency

The Rankine cycle is widely used for electricity production. Significant weight and size characteristics of the power equipment working on superheated steam are the main disadvantages of such power plants. The transition to supercritical carbon dioxide (S-CO2) working fluid is a promising way to achieve a significant reduction in equipment metal consumption and to increase energy efficiency. This paper presents the results of thermodynamic analysis of S-CO2 thermal power plants (TPPs) utilizing the heat of combustion products of an energy boiler. It was found that the net efficiency of the developed S-CO2 TPP with a pulverized coal-fired boiler reached 49.2% at an initial temperature of 780 °C, which was 2% higher compared to the efficiency level of steam turbine power plants (STPPs) at a similar turbine inlet temperature.

Analysis of Carbon Saving by the Adoption of Electric Vehicles in a Region Where Electricity Generation is Dominated by Thermal Power Plants

2021 ◽  
Author(s):  
Parakram Pyakurel ◽  
Filipe Quintal ◽  
James Auger ◽  
Julian Hanna
Keyword(s):  
Co2 Emissions ◽  
Electric Vehicles ◽  
Power Plants ◽  
Fossil Fuels ◽  
Fossil Fuel ◽  
Thermal Power ◽  
Primary Source ◽  
Electricity Production ◽  
Thermal Power Plants ◽  
Electrical Demand

One method of reducing atmospheric CO2 emissions in the transportation sector is the replacement of conventional fossil fuel-based vehicles with Electric Vehicles (EVs). However, fossil fuels are still the primary source of electricity production in many regions and the utilization of EVs in such regions increases the electricity demand because of battery charging. This results in increased burning of fossil fuels by thermal power plants and therefore can offset savings in CO2 emissions resulting from the adoption of EVs. In this paper, we consider a scenario where all fossil fuel-based conventional vehicles are replaced by EVs and then estimate the net CO2 emission savings resulting from the adoption of EVs in a region where electricity is primarily supplied by thermal plants. Only emissions generated during the operational phase of vehicle use are considered; emissions during the production phase are not considered. The region under consideration is Madeira, Portugal where thermal plants account for 80% of the total electricity produced. Our findings suggest that although EVs have huge potential to save CO2 emissions, a substantial amount of the savings can be offset due to the increased burning of fossil fuels by thermal plants to meet the electrical demand of charging batteries.

scholarly journals Improved Diagnosis of Boiler Feed Pumps in a Thermal Power Plant

2019 ◽  
Vol 9 (2) ◽  
pp. 931-935
Keyword(s):  
Power Plant ◽  
Thermal Power Plant ◽  
Vibration Analysis ◽  
Power Plants ◽  
Thermal Power ◽  
Electricity Production ◽  
Thermal Power Plants ◽  
Effective Solution ◽  
Operational Safety ◽  
Effective Diagnosis

In thermal power plants, the boiler feed pumps are classified as vital machines. Therefore, the lack of its availability leads immediately to a loss of electricity production. They can also be the source of serious incidents or accidents that directly threaten the operational safety of the machine, as well as the safety of personnel. The inspection is a very effective solution to reduce the possibility of an accident. The vibration analysis can specifically detect with opportunity the possible mechanical, hydraulic and electrical defects that probably exist in motor pump. This document presents different techniques of vibration analysis, which were applied in different pumps to make an effective diagnosis.

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.

Heat Transfer to Supercritical Water (Liquid-Like State) Flowing in a Short Vertical Bare Tube With Upward Flow

2018 ◽  
Author(s):  
A. Zvorykin ◽  
M. Mahdi ◽  
R. Popov ◽  
K. Barati Far ◽  
I. Pioro
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Supercritical Water ◽  
Thermal Efficiency ◽  
Power Plants ◽  
Thermal Power ◽  
Power Industry ◽  
Thermal Power Plants ◽  
Upward Flow ◽  
Bare Tube

Current Nuclear Power Plants (NPPs) equipped with water-cooled reactors (the vast majority of all NPPs) have relatively low thermal efficiencies within the range of 30–36% compared to those of modern advanced thermal power plants (SuperCritical Pressure (SCP) coal-fired — up to 55% thermal efficiency and combined cycle — up to 62%). Therefore, next generation reactors / NPPs should have higher thermal efficiencies close to those of current thermal power plants. Around 60 years ago thermal-power industry has moved from subcritical pressures to SCPs with the major objective to increase thermal efficiency. Based on this proven in power industry experience it was proposed to design SuperCritical Water-cooled Reactors (SCWRs), which are one of the six Generation-IV nuclear-reactor concepts under development in selected countries. These days, there are discussions on developing even Small Modular Reactors (SMRs) of SCPs. In spite of a large number of experiments in long bare tubes (pipes) cooled with SCW, developing SCWR concepts requires experimental data in bundle geometries cooled with SCW, which are usually shorter and will have smaller diameters. However, such experiments are extremely complicated and expensive plus each bundle geometry will have a unique Heat-Transfer (HT) characteristics due to various bundle designs. Therefore, as a preliminary and a universal approach — experiments in bare tube of shorter heated lengths and of smaller diameters to match heated lengths and hydraulic-equivalent diameters of fuel bundles are required. Current paper provides experimental data obtained in a short (0.6 m) vertical bare tube of a small diameter (6.28 mm) cooled with upward flow of SCW. Analysis of this dataset is also included. Main emphasis of this research is on liquid-like cooling within the possible conditions of future SCWRs and SCW SMRs. Two HT regimes are encountered at these conditions: 1) Normal HT (NHT) and 2) Deteriorated HT (DHT). Conditions at which the DHT regime appeared are discussed.

scholarly journals Enhancing properties of concrete by addition of fly ash from a thermal power plant for application in geothermal systems

2020 ◽  
Author(s):  
Milica Vlahović ◽  
◽  
Aleksandar Savić ◽  
Sanja Martinović ◽  
Nataša Đorđević ◽  
...  
Keyword(s):  
Fly Ash ◽  
Power Plant ◽  
Thermal Power Plant ◽  
Power Plants ◽  
Thermal Power ◽  
Electricity Production ◽  
Thermal Power Plants ◽  
Amorphous Sio2 ◽  
Positive Effects ◽  
Structural Applications

Electric power in Serbia is predominantly provided by thermal power plants. All of eleven existing thermal power plants in Serbia use coal, mainly lignite in the electricity production process thus generating about 6 million tons of fly ash per year. The estimated amount of fly ash from thermal power plants accumulated in Serbian landfills exceeds 200 million tons. On the other hand, during the last decades, respecting the principles of ecologically sustainable development has been imposed on industries, and one of them is the construction industry. Due to the presence of amorphous SiO2 and Al2O3, fly ash as pozzolanic material is convenient for the production of concrete and mortar. Consequently, multiple positive effects can be expected by the proper consumption of fly ash- reducing landfills and improving concrete properties. The idea of ​​this study is to analyze the possibility of recycling fly ash from a thermal power plant by replacing a part of common mineral filler- limestone in the production of self-compacting concrete (SCC). Properties of conventional SCC with limestone and compositions with different fly ash content were compared. Considering that requirements for SCC should be satisfied and all properties remain or enhance in the case of fly ash addition, this study proved that all designed concretes can be used for structural applications.

scholarly journals A study on the grindability of Serbian coals

2011 ◽  
Vol 15 (1) ◽  
pp. 267-274 ◽  
Author(s):  
Dejan Radic ◽  
Marko Obradovic ◽  
Miroslav Stanojevic ◽  
Aleksandar Jovovic ◽  
Dragoslava Stojiljkovic
Keyword(s):  
Power Plants ◽  
Thermal Power ◽  
Open Pit ◽  
Electricity Production ◽  
Mineral Matter ◽  
Thermal Power Plants ◽  
Lower Heating Value ◽  
Production Increase ◽  
The Republic ◽  
Hardgrove Grindability Index

Thermal power plants in the Republic of Serbia are making considerable efforts and even more considerable investments, not only to maintain electricity production at maximum design levels, but even to additionally increase the power output of existing generating units. Capacities of mills used in pulverized coal preparation are identified as one of the main constraints to achieving maximum mill plant capacity, while coal grindability is seen as one of the factors that directly affect capacities of the coal mills utilized in thermal power plants. The paper presents results of experimental investigation conducted for the purpose of determining Hardgrove grindability index of coal. The investigation was conducted in accordance with ISO 5074 and included analysis of approximately 70 coal samples taken from the open pit mine of Kolubara coal basin. Research results obtained indicate that coal rich in mineral matter and thus, of lower heating value is characterized by higher grindability index. Therefore, analyses presented in the paper suggest that characteristics of solid fuels analyzed in the research investigation conducted are such that the use coals less rich in mineral matter i. e. coals characterized by lower grindability index will cause coal mills to operate at reduced capacity. This fact should be taken into account when considering a potential for electricity production increase.

Simulation of Ancillary Services in Thermal Power Plants in Energy Systems With High Impact of Renewable Energy

2017 ◽  
Author(s):  
Moritz Huebel ◽  
Conrad Gierow ◽  
Jens Hinrich Prause ◽  
Sebastian Meinke ◽  
Egon Hassel
Keyword(s):  
Renewable Energy ◽  
Control System ◽  
Power Plants ◽  
Thermal Power ◽  
Ancillary Services ◽  
Electricity Production ◽  
Thermal Power Plants ◽  
Secondary Control ◽  
Primary And Secondary Control ◽  
The Impact

In many parts of the world, the impact of renewable energy, especially from intermittent sources as wind and solar is continuously increasing. In Germany, the share of renewable energy in electricity production is believed to increase from 32.5% in 2015 to 50% in 2030. In order to operate an electrical system and control the mains frequency, the power supply must match the consumption at any time. Ancillary services like primary and secondary control are used to balance the system on a time-scale of several seconds up to 15 minutes. Those control reserves are usually provided by thermal power plants. Particularly in times of high shares of fluctuating renewable feed-in, thermal power plants are turned off or operated at minimum load to avoid electricity production at low electricity prices. However, an amount of about 3000 MW of fast responding primary control need to be provided in the European network of transmission system operators for electricity grid to maintain stable operation even in case of two simultaneous large unit outages. This requirement leads to situations, where thermal power plants are operated in minimum load below their marginal cost to provide control reserves even if there is a surplus of energy in the grid. Operation in low load while at the same time providing control reserves leads to new challenges. As the relation between energy production and the thermal storage capacities provided by the metal and fluid mass in the boiler is decreasing with the load, the ability of responding to control demands is naturally slowed down. Dynamic simulation of the thermodynamic power plant process turned out to be an efficient method to investigate such operational modes. Using comprehensive process models coupled with a control system model, equipment adaptions or control system updates can be evaluated in order to provide faster responses. By increasing the specific amount of ancillary services per unit, the number of units necessary to provide the total amount of primary and secondary control could be reduced in situations with energy surplus.

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