scholarly journals Condensing power plant cycle — assessing possibilities of improving its efficiency

2010 ◽  
Vol 31 (3) ◽  
pp. 105-113 ◽  
Author(s):  
Tadeusz Chmielniak ◽  
Henryk Łukowicz
Keyword(s):  
Energy Dissipation ◽  
Power Plant ◽  
Power Plants ◽  
Rankine Cycle ◽  
Carnot Cycle ◽  
Current State

Condensing power plant cycle — assessing possibilities of improving its efficiency This paper presents a method for assessing the degree of approaching the paper output of the Clausius-Rankine cycle to the Carnot cycle. The computations to illustrate its use were performed for parameters characteristic of the current state of development of condensing power plants as well as in accordance with predicted trends for their further enhancing. Moreover there are presented computations of energy dissipation in the machines and devices working in such a cycle.

An analysis of a thermal power plant working on a Rankine cycle: A theoretical investigation

2008 ◽  
Vol 19 (1) ◽  
pp. 77-83 ◽  
Author(s):  
R.K. Kapooria ◽  
S. Kumar ◽  
K.S. Kasana
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Thermal Power ◽  
Rankine Cycle ◽  
Carnot Cycle ◽  
Steam Power ◽  
Factors Affecting ◽  
Steam Power Plants ◽  
Effi Ciency ◽  
Cycle Efficiency

Today, most of the electricity produced throughout the world is from steam power plants. However, electricity is being produced by some other power generation sources such as hydropower, gas power, bio-gas power, solar cells, etc. One newly devel-oped method of electricity generation is the Magneto hydro dynamic power plant. This paper deals with steam cycles used in power plants. Thermodynamic analysis of the Rankine cycle has been undertaken to enhance the efficiency and reli-ability of steam power plants. The thermodynamic deviations resulting in non-ideal or irreversible func-tioning of various steam power plant components have been identified. A comparative study between the Carnot cycle and Rankine cycle efficiency has been analyzed resulting in the introduction of regen-eration in the Rankine cycle. Factors affecting effi-ciency of the Rankine cycle have been identified and analyzed for improved working of thermal power plants.

scholarly journals Comparative Modeling of a Parabolic Trough Collectors Solar Power Plant with MARS Models

Energies ◽  
2017 ◽  
Vol 11 (1) ◽  
pp. 37 ◽  
Author(s):  
Jose Rogada ◽  
Lourdes Barcia ◽  
Juan Martinez ◽  
Mario Menendez ◽  
Francisco de Cos Juez
Keyword(s):  
Heat Transfer ◽  
Water Vapor ◽  
Power Plant ◽  
Solar Radiation ◽  
Thermal Energy ◽  
Power Plants ◽  
Solar Power ◽  
Rankine Cycle ◽  
Heat Transfer Fluid ◽  
Solar Field

Power plants producing energy through solar fields use a heat transfer fluid that lends itself to be influenced and changed by different variables. In solar power plants, a heat transfer fluid (HTF) is used to transfer the thermal energy of solar radiation through parabolic collectors to a water vapor Rankine cycle. In this way, a turbine is driven that produces electricity when coupled to an electric generator. These plants have a heat transfer system that converts the solar radiation into heat through a HTF, and transfers that thermal energy to the water vapor heat exchangers. The best possible performance in the Rankine cycle, and therefore in the thermal plant, is obtained when the HTF reaches its maximum temperature when leaving the solar field (SF). In addition, it is necessary that the HTF does not exceed its own maximum operating temperature, above which it degrades. The optimum temperature of the HTF is difficult to obtain, since the working conditions of the plant can change abruptly from moment to moment. Guaranteeing that this HTF operates at its optimal temperature to produce electricity through a Rankine cycle is a priority. The oil flowing through the solar field has the disadvantage of having a thermal limit. Therefore, this research focuses on trying to make sure that this fluid comes out of the solar field with the highest possible temperature. Modeling using data mining is revealed as an important tool for forecasting the performance of this kind of power plant. The purpose of this document is to provide a model that can be used to optimize the temperature control of the fluid without interfering with the normal operation of the plant. The results obtained with this model should be necessarily contrasted with those obtained in a real plant. Initially, we compare the PID (proportional–integral–derivative) models used in previous studies for the optimization of this type of plant with modeling using the multivariate adaptive regression splines (MARS) model.

Technical and Economical Feasibility of Biomass Use for Power Generation in Sicily

2012 ◽  
Vol 3 (1) ◽  
pp. 40-50 ◽  
Author(s):  
Antonio Messineo ◽  
Domenico Panno ◽  
Roberto Volpe
Keyword(s):  
Power Plant ◽  
Sustainable Management ◽  
Power Plants ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Geographical Information ◽  
Critical Issues ◽  
Economical Feasibility ◽  
Choice Of Technology

Biomass can provide a reliable support for production of biofuels while contributing to sustainable management of natural resources. Many countries, including Italy, have introduced important incentive schemes to support the use of biomass for electricity, heat and transportation. This has raised considerable interest towards the use of biomass for energy generation purposes. Nonetheless, the design and installation of biomass-fuelled power plants present several critical issues, such as choice and availability of biomass, choice of technology, power plant localization and logistics. The case study tackled in this paper evaluates the economies originated by a 1MWel Organic Rankine Cycle (ORC) turbine coupled with a biomass fuelled boiler, installed in an area close to Palermo (Italy). A Geographical Information System (GIS) was used to localize the power plant and to optimize logistics. The thermodynamics of the plant as a whole were also analyzed. Finally, two different scenarios were simulated for project financial evaluation.

On the Use of Thermal Energy Storage for Flexible Baseload Power Plants: Thermodynamic Analysis of Options for a Nuclear Rankine Cycle

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Fletcher Carlson ◽  
Jane H. Davidson
Keyword(s):  
Energy Storage ◽  
Power Plant ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Nuclear Power ◽  
Power Plants ◽  
Dynamic Balance ◽  
Rankine Cycle ◽  
Capacity Factor ◽  
Primary Cycle

Abstract The intermittency of wind and solar energy can disrupt the dynamic balance utilities must maintain to meet fluctuating demand. This work examines the use of thermal energy storage (TES) to increase the operational flexibility of a baseload power plant and thus incentivize renewable energy and decarbonize the grid. A first and second law thermodynamic model of a nuclear power plant establishes the impacts of TES on the capacity factor and thermal efficiency of the plant. Four storage options, which are distinguished by the location within the cycle where steam is diverted for charging and whether discharge of the TES is via the primary or a secondary Rankine cycle, are considered. TES is compared to steam bypass, which is an alternative to provide baseload flexibility. TES is significantly better than steam bypass. The storage option with the greatest thermodynamic benefit is charged by diverting superheated steam at the outlet of the moisture separator/reheater (MSR) to the TES. The TES is discharged for peaking power through an optimized secondary cycle. TES increases the capacity factor as much as 15% compared to steam bypass at representative charging mass flowrates. The storage option that diverts steam from the steam generator to charge the TES and discharges the TES to the primary cycle extends the discharge power to a lower range and does not require a secondary cycle. In this case, the capacity factor and efficiency are as much as 8% greater than that of steam bypass.

scholarly journals Prospects of diversification and ensuring energy safety of Uzbekistan

2019 ◽  
Vol 139 ◽  
pp. 01002 ◽  
Author(s):  
Kahraman Allaev ◽  
Tokhir Makhmudov
Keyword(s):  
Renewable Energy ◽  
Energy Balance ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Energy Security ◽  
Nuclear Power ◽  
Power Plants ◽  
Current State ◽  
The Republic

The data on the current state of energy in Uzbekistan are given. The need to diversify the structure of the energy balance of the republic is shown, which ensures the energy security of the state in the medium and long term. It is argued that the construction of a nuclear power plant in Uzbekistan is not only expedient, but also necessary. In the future, renewable energy and nuclear power plants will become the basis of energy in Uzbekistan.

scholarly journals Thermodynamic Analysis of Chemical Looping Combustion Based Power Plants for Gaseous and Solid Fuels

2021 ◽  
Author(s):  
Sivaji Seepana ◽  
Aritra Chakraborty ◽  
Kannan Kaliyaperumal ◽  
Guruchandran Pocha Saminathan
Keyword(s):  
Power Plant ◽  
Thermodynamic Analysis ◽  
Power Plants ◽  
Combustion Process ◽  
Rankine Cycle ◽  
Chemical Looping Combustion ◽  
Solid Fuels ◽  
Chemical Looping ◽  
Gaseous Fuels ◽  
The Difference

Abstract The chemical looping combustion (CLC) process is a promising technology for capturing CO2 at the source due to its inherent separation of flue gas from nitrogen. In this regard, the present study is focused on the development of various Rankine cycle based CLC power plant layouts for gaseous and solid fuels. To evaluate the performance of these CLC based cycles, a detailed thermodynamic analysis has been carried out with natural gas (NG)& synthesis gas as gaseous fuels and lignite as solid fuel. For lignite based power production, in-site gasification CLC (iG-CLC) for syngas generation and CLC based combustion process employed. The Energy analysis showed that NG based power plant has a net efficiency of 40.44% with CO2 capture and compression which is the highest among all cases while the same for syngas based power plant is 38.06%. The difference in net efficiency between NG and syngas power plants is attributed to the variation in CO2 compression cost. For lignite based iG-CLC power plant layout, the net efficiency of 39.64% is observed which is higher than syngas fuelledCLC power plant. This shows the potential of CLC technology for power generation applications with or without CO2 capture.

Case Study of the Puna Geothermal Power Plant and Proposed Retrofit H2S Gas Mitigation Strategies

2020 ◽  
Author(s):  
Kevin R. Anderson ◽  
Wael Yassine
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
State Of The Art ◽  
Mitigation Strategies ◽  
Geothermal Power Plant ◽  
Current State ◽  
Abatement Strategies ◽  
Simulation Results ◽  
Geothermal Power

Abstract This paper presents modeling of the Puna Geothermal Venture as a case study in understanding how the technology of geothermal can by successfully implemented. The paper presents a review of the Puna Geothermal Venture specifications, followed by simulation results carried out using NREL SAM and RETSCREEN analysis tools in order to quantify the pertinent metrics associated with the geothermal powerplant by retrofitting its current capacity of 30 MW to 60 MW. The paper closes with a review of current state-of-the art H2S abatement strategies for geothermal power plants, and presents an outline of how these technologies can be implemented at the Puna Geothermal Venture.

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].

Energy Conversion Using the Supercritical Steam Cycle

2017 ◽  
pp. 458-480
Author(s):  
Thomas Schulenberg
Keyword(s):  
Power Plant ◽  
Electric Power ◽  
Power Plants ◽  
Large Scale ◽  
Nuclear Reactors ◽  
Rankine Cycle ◽  
Boiler Design ◽  
Sliding Pressure ◽  
Technical Solutions ◽  
Supercritical Water Cooled Reactor

A supercritical steam (or Rankine) cycle is used today for more most of the new coal-fired power plants. More recently, it has been proposed as well for future water-cooled nuclear reactors to enhance their efficiency and to reduce their costs. This chapter provides the technical background explaining this technology. Some criteria for boiler design and operation, like drum or once-through boiler design, fixed or sliding pressure operation and coolant mixing, are discussed in general to explain the particular challenges of supercritical steam cycles. Examples of technical solutions are given for two large-scale applications: a coal-fired power plant and a supercritical water-cooled reactor, both producing around 1000 MW electric power.

Organic Rankine Cycle as Bottoming Cycle to a Combined Brayton and Clausius - Rankine Cycle

2013 ◽  
Vol 597 ◽  
pp. 87-98
Author(s):  
Dariusz Mikielewicz ◽  
Jan Wajs ◽  
Elżbieta Żmuda
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Large Scale ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Working Fluid ◽  
Preliminary Evaluation ◽  
Organic Fluids ◽  
Steam Cycle

A preliminary evaluation has been made of a possibility of bottoming of a conventional Brayton cycle cooperating with the CHP power plant with the organic Rankine cycle installation. Such solution contributes to the possibility of annual operation of that power plant, except of operation only in periods when there is a demand for the heat. Additional benefit would be the fact that an optimized backpressure steam cycle has the advantage of a smaller pressure ratio and therefore a less complex turbine design with smaller final diameter. In addition, a lower superheating temperature is required compared to a condensing steam cycle with the same evaporation pressure. Bottoming ORCs have previously been considered by Chacartegui et al. for combined cycle power plants [ Their main conclusion was that challenges are for the development of this technology in medium and large scale power generation are the development of reliable axial vapour turbines for organic fluids. Another study was made by Angelino et al. to improve the performance of steam power stations [. This paper presents an enhanced approach, as it will be considered here that the ORC installation could be extra-heated with the bleed steam, a concept presented by the authors in [. In such way the efficiency of the bottoming cycle can be increased and an amount of electricity generated increases. A thermodynamic analysis and a comparative study of the cycle efficiency for a simplified steam cycle cooperating with ORC cycle will be presented. The most commonly used organic fluids will be considered, namely R245fa, R134a, toluene, and 2 silicone oils (MM and MDM). Working fluid selection and its application area is being discussed based on fluid properties. The thermal efficiency is mainly determined by the temperature level of the heat source and the condenser conditions. The influence of several process parameters such as turbine inlet and condenser temperature, turbine isentropic efficiency, vapour quality and pressure, use of a regenerator (ORC) will be presented. Finally, some general and economic considerations related to the choice between a steam cycle and ORC are discussed.

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