scholarly journals THERMODYNAMICS ANALYSES ON REGENERATIVE STEAM CYCLE WITH TWO TANKS FOR HTGR-10 CONCEPT

2017 ◽  
Vol 20 (2) ◽  
pp. 73
Author(s):  
Sri Sudadiyo ◽  
Geni Rina Sunaryo
Keyword(s):  
Electric Power ◽  
Thermal Efficiency ◽  
Power Conversion ◽  
Working Fluid ◽  
Feed Water ◽  
Water Tank ◽  
Water Steam ◽  
Process Modification ◽  
Conversion Unit ◽  
Steam Cycle

THERMODYNAMICS ANALYSES ON REGENERATIVE STEAM CYCLE WITH TWO TANKS FOR HTGR-10 CONCEPT. In this work, steam cycle from a nuclear power plant is explored in order to increase electric power efficiency and output. A thermal source in the form of a HTGR-10 concept is considered. The power conversion unit of HTGR-10 consists of steam generators, turbines, condensers, pumps , and connecting pipes. Helium is used as the core coolant and the working fluid for power conversion unit is water/steam. The proposed thermodynamic process modification has been evaluated for regenerative steam power cycle of this reactor. The scope of study covered regenerative steam cycle with two tanks including feed water tank and intermediate feed water tank. The evaluation analyzes the effect of pressure, efficiencies of turbine and pumps, and tanks against thermal efficiency. The Cycle-Tempo software is used to simulate and optimize those effects on steam cycle based on HTGR-10. The results indicate improvements of as much as 2.65 % in thermal efficiency and 0.271 MWe in electric power.

Parametric Consideration of a Thermal Water Pump and Application for Agriculture

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Jirawat Sitranon ◽  
Charoenporn Lertsatitthanakorn ◽  
Pichai Namprakai ◽  
Naris Prathinthong ◽  
Taveewat Suparos ◽  
...  
Keyword(s):  
Thermal Water ◽  
Cooling Water ◽  
Check Valve ◽  
Working Fluid ◽  
Electric Heater ◽  
Feed Water ◽  
Vapor Flow ◽  
Pump Efficiency ◽  
Water Tank ◽  
Water Pump

This research studied the effects of suction heads on the efficiency of a thermal water pump with steam. In order to save energy, the authors also studied the appropriate amount of air added to a steam working fluid. Cooling time was attempted to be shorten, direct contact cooling was employed. The system comprised feed water tank (FT), liquid piston tank (LT), heat tank (HT), storage tank (ST), well tank (WT), and check valve (CV). It was directly cooled by cooling water. Thermal energy input was supplied by an electric heater as a substitute of heat sources such as firewood. An operation of the pump consisted of five stages: heating, pumping, vapor-flow, cooling, and suction. In conclusion, increasing the suction head raised the pumping efficiency until the maximum was achieved. Using air in conjunction with the steam working fluid could lower the working temperature suitable for solar application. In addition, the simulation of a thermal pump with steam was merely presented. A good agreement between the test and the model was found. The larger pump size was selected to be constructed and tested in order to increase the pump efficiency. Agricultural application of the larger pump could obtain energy source from waste of firewood at no cost.

Study on Primary and Secondary Heat-Transport Systems for Sodium-Cooled Fast Reactor

2013 ◽  
Author(s):  
Alexey Dragunov ◽  
Eugene Saltanov ◽  
Igor Pioro ◽  
Glenn Harvel ◽  
Brian Ikeda
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Heat Transport ◽  
Fast Reactor ◽  
Thermal Efficiency ◽  
Nuclear Power ◽  
Power Plants ◽  
Power Conversion ◽  
Gas Turbine Cycle ◽  
Steam Cycle

One of the current engineering challenges is to design next generation (Generation IV) Nuclear Power Plants (NPPs) with significantly higher thermal efficiencies (43–55%) compared to those of current NPPs to match or at least to be close to the thermal efficiencies reached at fossil-fired power plants (55–62%). The Sodium-cooled Fast Reactor (SFR) is one of the six concepts considered under the Generation IV International Forum (GIF) initiative. The BN-600 reactor is a sodium-cooled fast-breeder reactor built at the Beloyarsk NPP in Russia. This concept is the only one from the Generation IV nuclear-power reactors, which is actually in operation (since 1980’s). At the secondary side, it uses a subcritical-pressure Rankine-steam cycle with heat regeneration. The reactor generates electrical power in the amount of 600 MWel. The reactor core dimensions are 0.75 m (height) by 2.06 m (diameter). The UO2 fuel enriched to 17–26% is utilized in the core. There are 2 loops (circuits) for sodium flow. For safety reasons, sodium is used both in the primary and the intermediate circuits. Therefore, a sodium-to-sodium heat exchanger is used to transfer heat from the primary loop to the intermediate one. In this work major parameters of the reactor are listed. The actual scheme of the power-conversion heat-transport system is presented; and the results of the calculation of thermal efficiency of this scheme are analyzed. Details of the heat-transport system, including parameters of the sodium-to-sodium heat exchanger and main coolant pump, are presented. In this paper two possibilities for the SFR in terms of the power-conversion cycle are investigated: 1. a subcritical-pressure Rankine-steam cycle through a heat exchanger (current approach in Russian and Japanese power reactors); 2. a supercritical-pressure CO2 Brayton gas-turbine cycle through a heat exchanger (US approach). With the advent of modern super-alloys, the Rankine-steam cycle has progressed into the supercritical region of the coolant and is generating thermal efficiencies into the mid 50% range. Therefore, the thermal efficiency of a supercritical Rankine-steam cycle is also briefly discussed in this paper. According to GIF, the Brayton gas-turbine cycle is under consideration for future nuclear power reactors. The supercritical-CO2 cycle is a new approach in the Brayton gas-turbine cycle. Therefore, dependence of the thermal efficiency of this SC CO2 cycle on inlet parameters of the gas turbine is also investigated.

Experimental Investigation of a Single Stage Helium Axial Compressor of HTGR-10 Power Conversion Unit

2008 ◽  
Author(s):  
Rongkai Zhu ◽  
Qun Zheng ◽  
Jiguo Zou ◽  
Rakesh Bhargava
Keyword(s):  
Experimental Investigation ◽  
Power Conversion ◽  
Axial Compressor ◽  
Operating Conditions ◽  
Working Fluid ◽  
Brayton Cycle ◽  
Flow Conditions ◽  
Air Compressor ◽  
Conversion Unit ◽  
Compressor Performance

This paper focuses on an experimental investigation of a helium compressor, a major component of the Power Conversion Unit (PCU), used in a High Temperature Gas Cooled Reactor (HTGR). The PCU system uses a direct Helium Brayton cycle for the power conversion. In this configuration, there is a strong coupling between the helium compressor and the other components of the PCU system. The estimations of compressor performance in stable and transient operational states are of high importance for the designer. Because of the difficulties in testing a compressor with helium as a working fluid, simulations methods using air to replace helium as a compressor working fluid in the experiments are researched. An experimental compressor system is built to investigate the performance of a helium compressor. Under different operating conditions, the compressor performance characteristics are obtained and compared with that of an air compressor. The possibility and the effective approach of designing a helium compressor based on the experimental data of an air compressor are studied. The experimental results showed that air under the correct flow conditions, identified using similitude analysis, can be used to test a helium compressor instead of far more expensive helium.

Failure Analysis of a Low-Temperature Energy Conversion System Using Organic Rankine Cycles

2013 ◽  
Vol 864-867 ◽  
pp. 2127-2131
Author(s):  
Li Li Wei ◽  
Yu Feng Zhang ◽  
Yong Chao Mu
Keyword(s):  
Energy Conversion ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Practical Reasons ◽  
Medium Temperature ◽  
Water Steam ◽  
Design And Optimization ◽  
Working Medium ◽  
Conversion Unit ◽  
Organic Fluids

It is widely believed that Rankine cycle power plant using organic fluids as the working medium has advantages over conventional Rankine cycle with water steam as the working medium in low-to-medium temperature heat conversion. It is also testified in the market. However, besides the integration of the cycle and the characteristic of the working fluid, the design and debugging of the energy conversion unit are also important part in acquiring good performance. In this research some phenomenon of failure is investigated. Accordingly, the theoretical and practical reasons and solutions are obtained. It provides good guideline on the design and optimization of the energy conversion unit.

Thermodynamic Analysis of Zero-Atmospheric Emissions Power Plant

2002 ◽  
Author(s):  
Joel Martinez-Frias ◽  
Salvador M. Aceves ◽  
J. Ray Smith ◽  
Harry Brandt
Keyword(s):  
Carbon Dioxide ◽  
Power Plant ◽  
Electric Power ◽  
Thermodynamic Analysis ◽  
Thermal Efficiency ◽  
Operating Conditions ◽  
Air Separation ◽  
Working Fluid ◽  
Atmospheric Emissions ◽  
Gas Generator

This paper presents a thermodynamic analysis of a natural gas zero-atmospheric emissions power plant with a net electrical output of 400 MW. In this power plant, methane is combusted with oxygen in a gas generator to produce the working fluid for the turbines. The combustion produces a gas mixture composed of steam and carbon dioxide. These gases drive multiple turbines to produce electricity. The turbine discharge gases pass to a condenser where water is captured as liquid and gaseous carbon dioxide is pumped from the system. The carbon dioxide can be economically conditioned for enhanced recovery of oil, or coal-bed methane, or for sequestration in a subterranean formation. The analysis considers a complete power plant layout, including an air separation unit, compressors and intercoolers for oxygen and methane compression, a gas generator, three steam turbines, a reheater, a preheater, a condenser, and a carbon dioxide pumping system to pump the carbon dioxide to the pressure required for sequestration. The computer code is a powerful tool for estimating the efficiency of the plant, given different configurations and technologies. The efficiency of the power plant has been calculated over a wide range of conditions as a function of the two important power plant parameters of turbine inlet temperature and turbine isentropic efficiency. This simulation is based on a 400 MW electric power generating plant that uses turbines that are currently under development by a U.S. turbine manufacturer. The high-pressure turbine would operate at a temperature of 1089 K (1500 °F) with uncooled blades, the intermediate-pressure turbine would operate at 1478 K (2200 °F) with cooled blades and the low-pressure turbine would operate at 998 K (1336 °F). The corresponding turbine isentropic efficiencies for these three turbines were taken as 90, 91 and 93 percent. With these operating conditions, the zero-atmospheric emissions electric power plant has a net thermal efficiency of 46.5%. This net thermal efficiency is based on the lower heating value of methane, and includes the energy necessary for air separation and for carbon dioxide separation and sequestration.

Helium Brayton Cycles With Solar Central Receivers: Thermodynamic and Design Considerations

2012 ◽  
Author(s):  
Karsten Kusterer ◽  
René Braun ◽  
Norbert Moritz ◽  
Gang Lin ◽  
Dieter Bohn
Keyword(s):  
Energy Conversion ◽  
Electric Power ◽  
Thermal Efficiency ◽  
Power Plants ◽  
Solar Irradiation ◽  
Brayton Cycle ◽  
Gas Temperature ◽  
Water Steam ◽  
Capital Costs ◽  
Design Considerations

Concentrated Solar Power (CSP) technologies are considered to provide a major contribution for the electric power production in the future. Several technologies for such kind of power plants are already in operation. Parabolic troughs, parabolic dishes, Fresnel multi-facet reflectors or heliostats in combination with a central receiver are applied for concentration of the solar irradiation. The energy conversion cycles usually are water/steam cycles (Rankine cycles), but also open gas turbine cycles (Brayton cycle) or combined cycles are possible. One option is to apply closed Brayton cycles using fluids like carbon dioxide or helium. With respect to commercial considerations, the main parameter driving the decision on which cycle to apply for energy conversion is the thermal efficiency of the process. This is due to the fact, that in case of a power plant without additional fuel supply, no fuel costs have to be considered to determine the levelized electricity costs (LEC). Thus, in the first place the capital costs determine the LEC. In CSP plants one main driver for the capital costs are the heliostats and the mirror size, which are necessary to generate the desired amount of electric power. The necessary solar aperture area directly depends on the thermal efficiency of the energy conversion cycle. In this paper different closed Helium Brayton Cycles for application with solar central receivers are analyzed thermodynamically. The thermodynamic calculations are performed by application of a self-developed thermodynamic calculation software, which considers the real gas properties of the fluid. The software calculates the cycle’s thermodynamic diagrams (e.g. T-s-, h-s-diagrams) and determines its efficiency. The results show that thermal efficiencies of approximately 46.6% (and higher) can be reached with a Helium Brayton Cycle. One important parameter is the turbine inlet gas temperature, which is not less than 900 °C. This means that the pressurized receiver for this technology has to bear even higher temperatures. Furthermore, the paper deals with design considerations for compressor and turbine within the closed Helium Brayton Cycle. Based on dimensionless parameters, the major parameters like stage types, number of stages, rotational speed etc. are determined and discussed.

scholarly journals Improving flexibility characteristics of 200 MW unit

2017 ◽  
Vol 38 (1) ◽  
pp. 75-90 ◽  
Author(s):  
Jan Taler ◽  
Marcin Trojan ◽  
Dawid Taler ◽  
Piotr Dzierwa ◽  
Karol Kaczmarski
Keyword(s):  
Electric Power ◽  
Power Unit ◽  
Water Pressure ◽  
Low Pressure ◽  
Hot Water ◽  
Feed Water ◽  
Sudden Increase ◽  
Water Tank ◽  
Peak Demand ◽  
Profitability Analysis

Abstract Calculations were performed of the thermal system of a power plant with installed water pressure tanks. The maximum rise in the block electric power resulting from the shut-off of low-pressure regenerative heaters is determined. At that time, the boiler is fed with hot water from water pressure tanks acting as heat accumulators. Accumulation of hot water in water tanks is also proposed in the periods of the power unit small load. In order to lower the plant electric power in the off-peak night hours, water heated in low-pressure regenerative heaters and feed water tank to the nominal temperature is directed to water pressure tanks. The water accumulated during the night is used to feed the boiler during the period of peak demand for electricity. Drops in the power block electric power were determined for different capacities of the tanks and periods when they are charged. A financial and economic profitability analysis (of costs and benefits) is made of the use of tanks for a 200 MW power unit. Operating in the automatic system of frequency and power control, the tanks may also be used to ensure a sudden increase in the electric power of the unit. The results of the performed calculations and analyses indicate that installation of water pressure tanks is well justified. The investment is profitable. Water pressure tanks may not only be used to reduce the power unit power during the off-peak night hours and raise it in the periods of peak demand, but also to increase the power capacity fast at any time. They may also be used to fill the boiler evaporator with hot water during the power unit start-up from the cold state.

Construction of a 100 kW Solar Thermal-Electric Experimental Plant

1985 ◽  
Vol 107 (3) ◽  
pp. 196-201 ◽  
Author(s):  
J. L. Boy-Marcotte ◽  
M. Dancette ◽  
J. Bliaux ◽  
E. Bacconnet ◽  
J. Malherbe
Keyword(s):  
Energy Storage ◽  
Power Plant ◽  
Electric Power ◽  
Thermal Energy ◽  
Power Conversion ◽  
Working Fluid ◽  
Experimental Plant ◽  
Cooling Towers ◽  
Thermal Electric Power Plant ◽  
Solar Plant

A focusing collector thermal-electric power plant has been erected in Corsica (France). This plant consists of a field of 1176 m2 fixed mirror concentrators, producing heat at 250° C, a stratification thermal energy storage of about 1250 kWh, two power conversion units of 45 kWe each, with a supersonic turbine expanding a heavy organic working fluid, and two cooling towers of 200 kW each. This full-scale prototype has been built mainly to demonstrate the capability of the distributed collector solar plant concept, in the power range from 50 kWe to 1000 kWe, and the temperature range from 150 to 300° C. This paper describes the conceptual design and the performance of the plant, and discusses problems that were met during construction.

Stress Analyses of Intermediate Heat Transfer Loop

2008 ◽  
Author(s):  
Chang H. Oh ◽  
Eung Soo Kim ◽  
Steven Sherman
Keyword(s):  
High Temperature ◽  
Hydrogen Production ◽  
Heat Transport ◽  
Power Conversion ◽  
Working Fluid ◽  
Production Plant ◽  
Next Generation ◽  
Working Fluids ◽  
Conversion Unit ◽  
Electrical Generation

The Department of Energy and the Idaho National Laboratory are developing a Next Generation Nuclear Plant (NGNP) to serve as a demonstration of state-of-the-art nuclear technology. The purpose of the demonstration is two fold 1) efficient low cost energy generation and 2) hydrogen production. Although a next generation plant could be developed as a single-purpose facility dedicated to hydrogen production, early designs are expected to be dual purpose. While hydrogen production and advanced energy cycles are still in its early stages of development, research towards coupling a high temperature reactor with electrical generation and hydrogen production is under way. Many aspects of the NGNP must be researched and developed in order to make recommendations on the final design of the plant. Parameters such as working conditions, cycle components, working fluids, and power conversion unit configurations must be understood. A number of configurations of the power conversion unit were demonstrated in this study. An intermediate heat transport loop for transporting process heat to a High Temperature Steam Electrolysis (HTSE) hydrogen production plant was used. Helium, CO2, and a 80% nitrogen, 20% helium mixture (by weight) were studied to determine the best working fluid in terms cycle efficiency and development cost. In each of these configurations the relative component sizes were estimated for the different working fluids. Parametric studies were carried out on reactor outlet temperature, mass flow, pressure, and turbine cooling. Recommendations on the optimal working fluid for each configuration were made. Engineering analyses were performed for several configurations of the intermediate heat transport loop that transfers heat from the nuclear reactor to the hydrogen production plant. The analyses evaluated parallel and concentric piping arrangements and two different working fluids, including helium and a liquid salt. The thermal-hydraulic analyses determined the size and insulation requirements for the hot and cold leg pipes in the different configurations. Mechanical analyses were performed to determine hoop stresses and thermal expansion characteristics for the different configurations.

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