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Sample records for hhfw heating power

  1. Towards identifying the mechanisms underlying field-aligned edge-loss of HHFW power on NSTX

    Energy Technology Data Exchange (ETDEWEB)

    Perkins, R. J.; Bell, R. E.; Bertelli, N.; Diallo, A.; Gerhardt, S.; Hosea, J. C.; Jaworski, M. A.; LeBlanc, B. P.; Kramer, G. J.; Maingi, R.; Phillips, C. K.; Podestà, M.; Roquemore, L.; Scotti, F.; Taylor, G.; Wilson, J. R. [Princeton Plasma Physics Laboratory, Princeton, NJ (United States); Ahn, J-W.; Gray, T. K.; Green, D. L.; McLean, A. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); and others

    2014-02-12

    Fast-wave heating will be a major heating scheme on ITER, as it can heat ions directly and is relatively unaffected by the large machine size unlike neutral beams. However, fast-wave interactions with the plasma edge can lead to deleterious effects such as, in the case of the high-harmonic fast-wave (HHFW) system on NSTX, large losses of fast-wave power in the scrape off layer (SOL) under certain conditions. In such scenarios, a large fraction of the lost HHFW power is deposited on the upper and lower divertors in bright spiral shapes. The responsible mechanism(s) has not yet been identified but may include fast-wave propagation in the scrape off layer, parametric decay instability, and RF currents driven by the antenna reactive fields. Understanding and mitigating these losses is important not only for improving the heating and current-drive on NSTX-Upgrade but also for understanding fast-wave propagation across the SOL in any fast-wave system. This talk summarizes experimental results demonstrating that the flow of lost HHFW power to the divertor regions largely follows the open SOL magnetic field lines. This lost power flux is relatively large close to both the antenna and the last closed flux surface with a reduced level in between, so the loss mechanism cannot be localized to the antenna. At the same time, significant losses also occur along field lines connected to the inboard edge of the bottom antenna plate. The power lost within the spirals is roughly estimated, showing that these field-aligned losses to the divertor are significant but may not account for the total HHFW loss. To elucidate the role of the onset layer for perpendicular fast-wave propagation with regards to fast-wave propagation in the SOL, a cylindrical cold-plasma model is being developed. This model, in addition to advanced RF codes such as TORIC and AORSA, is aimed at identifying the underlying mechanism(s) behind these SOL losses, to minimize their effects in NSTX-U, and to predict

  2. Towards identifying the mechanisms underlying field-aligned edge-loss of HHFW power on NSTX

    International Nuclear Information System (INIS)

    Perkins, R. J.; Bell, R. E.; Bertelli, N.; Diallo, A.; Gerhardt, S.; Hosea, J. C.; Jaworski, M. A.; LeBlanc, B. P.; Kramer, G. J.; Maingi, R.; Phillips, C. K.; Podestà, M.; Roquemore, L.; Scotti, F.; Taylor, G.; Wilson, J. R.; Ahn, J-W.; Gray, T. K.; Green, D. L.; McLean, A.

    2014-01-01

    Fast-wave heating will be a major heating scheme on ITER, as it can heat ions directly and is relatively unaffected by the large machine size unlike neutral beams. However, fast-wave interactions with the plasma edge can lead to deleterious effects such as, in the case of the high-harmonic fast-wave (HHFW) system on NSTX, large losses of fast-wave power in the scrape off layer (SOL) under certain conditions. In such scenarios, a large fraction of the lost HHFW power is deposited on the upper and lower divertors in bright spiral shapes. The responsible mechanism(s) has not yet been identified but may include fast-wave propagation in the scrape off layer, parametric decay instability, and RF currents driven by the antenna reactive fields. Understanding and mitigating these losses is important not only for improving the heating and current-drive on NSTX-Upgrade but also for understanding fast-wave propagation across the SOL in any fast-wave system. This talk summarizes experimental results demonstrating that the flow of lost HHFW power to the divertor regions largely follows the open SOL magnetic field lines. This lost power flux is relatively large close to both the antenna and the last closed flux surface with a reduced level in between, so the loss mechanism cannot be localized to the antenna. At the same time, significant losses also occur along field lines connected to the inboard edge of the bottom antenna plate. The power lost within the spirals is roughly estimated, showing that these field-aligned losses to the divertor are significant but may not account for the total HHFW loss. To elucidate the role of the onset layer for perpendicular fast-wave propagation with regards to fast-wave propagation in the SOL, a cylindrical cold-plasma model is being developed. This model, in addition to advanced RF codes such as TORIC and AORSA, is aimed at identifying the underlying mechanism(s) behind these SOL losses, to minimize their effects in NSTX-U, and to predict

  3. Electron Energy Confinement for HHFW Heating and Current Drive Phasing on NSTX

    International Nuclear Information System (INIS)

    Hosea, J.C.; Bernabei, S.; Biewer, T.; LeBlanc, B.; Phillips, C.K.; Wilson, J.R.; Stutman, D.; Ryan, P.; Swain, D.W.

    2005-01-01

    Thomson scattering laser pulses are synchronized relative to modulated HHFW power to permit evaluation of the electron energy confinement time during and following HHFW pulses for both heating and current drive antenna phasing. Profile changes resulting from instabilities require that the total electron stored energy, evaluated by integrating the midplane electron pressure P(sub)e(R) over the magnetic surfaces prescribed by EFIT analysis, be used to derive the electron energy confinement time. Core confinement is reduced during a sawtooth instability but, although the electron energy is distributed outward by the sawtooth, the bulk electron energy confinement time is essentially unaffected. The radial deposition of energy into the electrons is noticeably more peaked for current drive phasing (longer wavelength excitation) relative to that for heating phasing (shorter wavelength excitation) as is expected theoretically. However, the power delivered to the core plasma is reduced consider ably for the current drive phasing, indicating that surface/peripheral damping processes play a more important role for this case

  4. Parametric Decay during HHFW on NSTX

    International Nuclear Information System (INIS)

    Wilson, J.R.; Bernabei, S.; Biewer, T.; Diem, S.; Hosea, J.; LeBlanc, B.; Phillips, C.K.; Ryan, P.; Swain, D.W.

    2005-01-01

    High Harmonic Fast Wave (HHFW) heating experiments on NSTX have been observed to be accompanied by significant edge ion heating (T i >> T e ). This heating is found to be anisotropic with T perp > T par . Simultaneously, coherent oscillations have been detected with an edge Langmuir probe. The oscillations are consistent with parametric decay of the incident fast wave (ω > 13ω ci ) into ion Bernstein waves and an unobserved ion-cyclotron quasi-mode. The observation of anisotropic heating is consistent with Bernstein wave damping, and the Bernstein waves should completely damp in the plasma periphery as they propagate toward a cyclotron harmonic resonance. The number of daughter waves is found to increase with rf power, and to increase as the incident wave's toroidal wavelength increases. The frequencies of the daughter wave are separated by the edge ion cyclotron frequency. Theoretical calculations of the threshold for this decay in uniform plasma indicate an extremely small value of incident power should be required to drive the instability. While such decays are commonly observed at lower harmonics in conventional ICRF heating scenarios, they usually do not involve the loss of significant wave power from the pump wave. On NSTX an estimate of the power loss can be found by calculating the minimum power required to support the edge ion heating (presumed to come from the decay Bernstein wave). This calculation indicates at least 20-30% of the incident rf power ends up as decay waves

  5. Self-consistent calculation of the effects of RF injection in the HHFW heating regimes on the evolution of fast ions in toroidal plasmas

    Directory of Open Access Journals (Sweden)

    Bertelli Nicola

    2017-01-01

    Full Text Available A critical question for the use of ion cyclotron range of frequency (ICRF heating in the ITER device and beyond is interaction of fast waves with energetic ion populations from neutral beam injection (NBI, fusion reactions, and minority ions accelerated by the RF waves themselves. Several experiments have demonstrated that the interaction between fast waves and fast ions can indeed be strong enough to significantly modify the NB ion population. To model the RF/fast ion interaction and the resulting fast ion distribution, a recent extension of the full wave solver TORIC v.5 that includes non-Maxwellian effects has been combined with the Monte Carlo NUBEAM code through an RF “kick” operator. In this work, we present an initial verification of the NUBEAM RF “kick” operator for high harmonic fast wave (HHFW heating regime in NSTX plasma.

  6. Transport in Auxiliary Heated NSTX Discharges

    International Nuclear Information System (INIS)

    LeBlanc, B.P.; Bell, M.G.; Bell, R.E.; Bitte, M.L.; Bourdelle, C.; Gates, D.A.; Kaye, S.M.; Maingi, R.; Menard, J.E.; Mueller, D.; Ono, M.; Paul, S.F.; Redi, M.H.; Roquemore, A.L.; Rosenberg, A.; Sabbagh, S.A.; Stutman, D.; Synakowski, E.J.; Soukhanovskii, V.A.; Wilson, J.R.

    2003-01-01

    The NSTX spherical torus (ST) provides a unique platform to investigate magnetic confinement in auxiliary-heated plasmas at low aspect ratio. Auxiliary power is routinely coupled to ohmically heated plasmas by deuterium neutral-beam injection (NBI) and by high-harmonic fast waves (HHFW) launch. While theory predicts both techniques to preferentially heat electrons, experiment reveals the electron temperature is greater than the ion temperature during HHFW, but the electron temperature is less than the ion temperature during NBI. In the following we present the experimental data and the results of transport analyses

  7. Electrical testing of the full-scale model of the NSTX HHFW antenna array

    International Nuclear Information System (INIS)

    Ryan, P. M.; Swain, D. W.; Wilgen, J. B.; Fadnek, A.; Sparks, D. O.

    1999-01-01

    The 30 MHz high harmonic fast wave (HHFW) antenna array for NSTX consists of 12 current straps, evenly spaced in the toroidal direction. Each pair of straps is connected as a half-wave resonant loop and will be driven by one transmitter, allowing rapid phase shift between transmitters. A decoupling network using shunt stub tuners has been designed to compensate for the mutual inductive coupling between adjacent current straps, effectively isolating the six transmitters from one another. One half of the array, consisting of six full-scale current strap modules, three shunt stub decouplers, and powered by three phase-adjustable rf amplifiers had been built for electrical testing at ORNL. Low power testing includes electrical characterization of the straps, operation and performance of the decoupler system, and mapping of the rf fields in three dimensions

  8. Heat and power from combustibles

    International Nuclear Information System (INIS)

    Zogg, M.

    2002-01-01

    This article compares four ways of generating heat and power from liquid and gaseous fuels. Various combinations of conventional boilers, heat pumps, combined heat and power units and combined-cycle power plants are considered and the ratio of heat to electrical power produced is discussed. Fuel requirements for the four combinations are looked at and net emissions of carbon dioxide, oxides of nitrogen and carbon monoxide presented in graphical form. The author makes recommendations on the choice of the technology to be used to generate heat and electricity for different heat/power ratios and criticises the all too slack emission limits for small combined heat and power units

  9. RF heating and current drive on NSTX with high harmonic fast waves

    International Nuclear Information System (INIS)

    Ryan, P.M.

    2002-01-01

    NSTX is a small aspect ratio tokamak with a large dielectric constant (50-100); under these conditions high harmonic fast waves (HHFW) will readily damp on electrons via Landau damping and TTMP. The HHFW system is a 30 MHz, 12-element array capable of launching both symmetric and directional wave spectra for plasma heating and non-inductive current drive. It has delivered up to 6 MW for short pulses and has routinely operated at ∼3-4 MW for 100-200 ms pulses. Results include strong, centrally-peaked electron heating in both D and He plasmas, for both high and low phase velocity spectra. H-modes were obtained with application of HHFW power alone, with stored energy doubling after the L-H transition. Beta poloidal as large as unity has been obtained with large fractions (0.4) of bootstrap current. A fast ion tail with energies extending up to 140 keV has been observed when HHFW interacts with 80 keV neutral beams; neutron rate and lost ion measurements, as well as modeling, indicate significant power absorption by the fast ions. Radial power deposition profiles are being calculated with ray tracing and kinetic full-wave codes and benchmarked against measurements. (author)

  10. Combined Heat and Power

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    At their 2007 Summit in Heiligendamm, G8 leaders called on countries to 'adopt instruments and measures to significantly increase the share of combined heat and power (CHP) in the generation of electricity.' As a result, energy, economic, environmental and utility regulators are looking for tools and information to understand the potential of CHP and to identify appropriate policies for their national circumstances. This report forms the first part of the response. It includes answers to policy makers' questions about the potential economic, energy and environmental benefits of an increased policy commitment to CHP. It also includes for the first time integrated IEA data on global CHP installations, and analyses the benefits of increased CHP investment in the G8+5 countries. A companion report will be produced later in 2008 to document best practice policy approaches that have been used to expand the use of CHP in a variety of countries.

  11. Fast wave power flow along SOL field lines in NSTX

    Science.gov (United States)

    Perkins, R. J.; Bell, R. E.; Diallo, A.; Gerhardt, S.; Hosea, J. C.; Jaworski, M. A.; Leblanc, B. P.; Kramer, G. J.; Phillips, C. K.; Roquemore, L.; Taylor, G.; Wilson, J. R.; Ahn, J.-W.; Gray, T. K.; Green, D. L.; McLean, A.; Maingi, R.; Ryan, P. M.; Jaeger, E. F.; Sabbagh, S.

    2012-10-01

    On NSTX, a major loss of high-harmonic fast wave (HHFW) power can occur along open field lines passing in front of the antenna over the width of the scrape-off layer (SOL). Up to 60% of the RF power can be lost and at least partially deposited in bright spirals on the divertor floor and ceiling [1,2]. The flow of HHFW power from the antenna region to the divertor is mostly aligned along the SOL magnetic field [3], which explains the pattern of heat deposition as measured with infrared (IR) cameras. By tracing field lines from the divertor back to the midplane, the IR data can be used to estimate the profile of HHFW power coupled to SOL field lines. We hypothesize that surface waves are being excited in the SOL, and these results should benchmark advanced simulations of the RF power deposition in the SOL (e.g., [4]). Minimizing this loss is critical optimal high-power long-pulse ICRF heating on ITER while guarding against excessive divertor erosion.[4pt] [1] J.C. Hosea et al., AIP Conf Proceedings 1187 (2009) 105. [0pt] [2] G. Taylor et al., Phys. Plasmas 17 (2010) 056114. [0pt] [3] R.J. Perkins et al., to appear in Phys. Rev. Lett. [0pt] [4] D.L. Green et al., Phys. Rev. Lett. 107 (2011) 145001.

  12. Edge Ion Heating by Launched High Harmonic Fast Waves in NSTX

    International Nuclear Information System (INIS)

    Biewer, T.M.; Bell, R.E.; Diem, S.J.; Phillips, C.K.; Wilson, J.R.; Ryan, P.M.

    2004-01-01

    A new spectroscopic diagnostic on the National Spherical Torus Experiment (NSTX) measures the velocity distribution of ions in the plasma edge simultaneously along both poloidal and toroidal views. An anisotropic ion temperature is measured during high-power high harmonic fast wave (HHFW) radio-frequency (rf) heating in helium plasmas, with the poloidal ion temperature roughly twice the toroidal ion temperature. Moreover, the measured spectral distribution suggests that two populations of ions are present and have temperatures of typically 500 eV and 50 eV with rotation velocities of -50 km/s and -10 km/s, respectively (predominantly perpendicular to the local magnetic field). This bi-modal distribution is observed in both the toroidal and poloidal views (for both He + and C 2+ ions), and is well correlated with the period of rf power application to the plasma. The temperature of the hot component is observed to increase with the applied rf power, which was scanned between 0 and 4.3 MW . The 30 MHz HHFW launched by the NSTX antenna is expected and observed to heat core electrons, but plasma ions do not resonate with the launched wave, which is typically at >10th harmonic of the ion cyclotron frequency in the region of observation. A likely ion heating mechanism is parametric decay of the launched HHFW into an Ion Bernstein Wave (IBW). The presence of the IBW in NSTX plasmas during HHFW application has been directly confirmed with probe measurements. IBW heating occurs in the perpendicular ion distribution, consistent with the toroidal and poloidal observations. Calculations of IBW propagation indicate that multiple waves could be created in the parametric decay process, and that most of the IBW power would be absorbed in the outer 10 to 20 cm of the plasma, predominantly on fully stripped ions. These predictions are in qualitative agreement with the observations, and must be accounted for when calculating the energy budget of the plasma

  13. Thermodynamics and heat power

    CERN Document Server

    Granet, Irving

    2014-01-01

    Fundamental ConceptsIntroductionThermodynamic SystemsTemperatureForce and MassElementary Kinetic Theory of GasesPressureReviewKey TermsEquations Developed in This ChapterQuestionsProblemsWork, Energy, and HeatIntroductionWorkEnergyInternal EnergyPotential EnergyKinetic EnergyHeatFlow WorkNonflow WorkReviewKey TermsEquations Developed in This ChapterQuestionsProblemsFirst Law of ThermodynamicsIntroductionFirst Law of ThermodynamicsNonflow SystemSteady-Flow SystemApplications of First Law of ThermodynamicsReviewKey TermsEquations Developed in This ChapterQuestionsProblemsThe Second Law of ThermodynamicsIntroductionReversibility-Second Law of ThermodynamicsThe Carnot CycleEntropyReviewKey TermsEquations Developed in This ChapterQuestionsProblemsProperties of Liquids and GasesIntroductionLiquids and VaporsThermodynamic Properties of SteamComputerized PropertiesThermodynamic DiagramsProcessesReviewKey TermsEquations Developed in This ChapterQuestionsProblemsThe Ideal GasIntroductionBasic ConsiderationsSpecific Hea...

  14. RF heating and current drive on NSTX with high harmonic fast waves

    International Nuclear Information System (INIS)

    Ryan, P.M.; Swain, D.W.; Rosenberg, A.L.

    2003-01-01

    NSTX is a small aspect ratio tokamak (R = 0.85 m, a = 0.65 m). The High Harmonic Fast Wave (HHFW) system is a 30 MHz, 12-element array capable of launching both symmetric and directional wave spectra for plasma heating and non-inductive current drive. It has delivered up to 6 MW for short pulses and has routinely operated at ∼3 MW for 100-400 ms pulses. Results include strong, centrally-peaked electron heating in both D and He plasmas for both high and low phase velocity spectra. H-modes were obtained with application of HHFW power alone, with stored energy doubling after the L-H transition. Beta poloidal as large as unity has been obtained with significant fractions (0.4) of bootstrap current. Differences in the loop voltage are observed depending on whether the array is phased to drive current in the co- or counter-current directions. A fast ion tail with energies extending up to 140 keV has been observed when HHFW interacts with 80 keV neutral beams; neutron rate and lost ion measurements, as well as modeling, indicate significant power absorption by the fast ions. Radial rf power deposition and driven current profiles have been calculated with ray tracing and kinetic full-wave codes and compared with measurements. (author)

  15. Waste heat of HTR power stations for district heating

    International Nuclear Information System (INIS)

    Bonnenberg, H.; Schlenker, H.V.

    1975-01-01

    The market situation, the applied techniques, and the transport, for district heating in combination with HTR plants are considered. Analysis of the heat market indicates a high demand for heat at temperatures between 100 and 150 0 C in household and industry. This market for district heating can be supplied by heat generated in HTR plants using two methods: (1) the combined heat and power generation in steam cycle plants by extracting steam from the turbine, and (2) the use of waste heat of a closed gas turbine cycle. The heat generation costs of (2) are negligible. The cost for transportation of heat over the average distance between existing plant sites and consumer regions (25 km) are between 10 and 20% of the total heat price, considering the high heat output of nuclear power stations. Comparing the price of heat gained by use of waste heat in HTR plants with that of conventional methods, considerable advantages are indicated for the combined heat and power generation in HTR plants. (author)

  16. Heat supply from nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Stach, V [Ustav Jaderneho Vyzkumu CSKAE, Rez (Czechoslovakia)

    1978-05-01

    The current state of world power production and consumption is assessed. Prognoses made for the years 1980 to 2000 show that nuclear energy should replace the major part of fossil fuels not only in the production of power but also in the production of heat. In this respect high-temperature reactors are highly prospective. The question is discussed of the technical and economic parameters of dual-purpose heat and power plants. It is, however, necessary to solve problems arising from the safe siting of nuclear heat and power plants and their environmental impacts. The economic benefits of combined power and heat production by such nuclear plants is evident.

  17. Spectral Effects on Fast Wave Core Heating and Current Drive

    International Nuclear Information System (INIS)

    Phillips, C.K.; Bell, R.E.; Berry, L.A.; Bonoli, P.T.; Harvey, R.W.; Hosea, J.C.; Jaeger, E.F.; LeBlanc, B.P.; Ryan, P.M.; Taylor, G.; Valeo, E.J.; Wilson, J.R.; Wright, J.C.; Yuh, H. and the NSTX Team

    2009-01-01

    Recent results obtained with high harmonic fast wave (HHFW) heating and current drive (CD) on NSTX strongly support the hypothesis that the onset of perpendicular fast wave propagation right at or very near the launcher is a primary cause for a reduction in core heating efficiency at long wavelengths that is also observed in ICRF heating experiments in numerous tokamaks. A dramatic increase in core heating efficiency was first achieved in NSTX L-mode helium majority plasmas when the onset for perpendicular wave propagation was moved away from the antenna and nearby vessel structures. Efficient core heating in deuterium majority L mode and H mode discharges, in which the edge density is typically higher than in comparable helium majority plasmas, was then accomplished by reducing the edge density in front of the launcher with lithium conditioning and avoiding operational points prone to instabilities. These results indicate that careful tailoring of the edge density profiles in ITER should be considered to limit rf power losses to the antenna and plasma facing materials. Finally, in plasmas with reduced rf power losses in the edge regions, the first direct measurements of high harmonic fast wave current drive were obtained with the motional Stark effect (MSE) diagnostic. The location and radial dependence of HHFW CD measured by MSE are in reasonable agreement with predictions from both full wave and ray tracing simulations

  18. Heat pumps in combined heat and power systems

    DEFF Research Database (Denmark)

    Ommen, Torben Schmidt; Markussen, Wiebke Brix; Elmegaard, Brian

    2014-01-01

    Heat pumps have previously been proposed as a way to integrate higher amounts of renewable energy in DH (district heating) networks by integrating, e.g., wind power. The paper identifies and compares five generic configurations of heat pumps in DH systems. The operational performance...... of the considered cases. When considering a case where the heat pump is located at a CHP (combined heat and power) plant, a configuration that increases the DH return temperature proposes the lowest operation cost, as low as 12 EUR MWh-1 for a 90 °C e 40 °C DH network. Considering the volumetric heating capacity......, a third configuration is superior in all cases. Finally, the three most promising heat pump configurations are integrated in a modified PQ-diagram of the CHP plant. Each show individual advantages, and for two, also disadvantages in order to achieve flexible operation....

  19. Cyro Power and Heat Transfer

    National Research Council Canada - National Science Library

    Chow, L

    1998-01-01

    .... The heat generated from a 9x9-heater array was removed by liquid nitrogen pool boiling. The orientation and space limitation of the array were varied to explore their effects on the critical heat flux (CHF) value...

  20. Heat exchanger. [Nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Molina, C; Brisseaux, A

    1976-01-19

    This invention concerns a heat exchanger between a fluid flowing through a tube and a gas. Such an exchanger can be used, inter alia, for removing calories that cannot be used for generating electricity in a thermal or nuclear power station. This exchanger can withstand any pressure surges in the system and even the use of a high vapour pressure coolant such as ammonia, since the fluid flows in a round tube with low pressure drops (both with respect to the fluid to be cooled and the cooling air). It is rigid enough to stand up to being moved and handled as well as to gusts of wind. It is formed of units that can be handled without difficulty and that are easily dismantable and interchangeable, even in service, and it is easily maintained. The exchange area is high for a minimum frontal area and this enables the size of the supporting frame to be reduced and makes it easy to hide it behind a screen of trees should this prove necessary. Finally, it is composed of a small number of standard units thus reducing the industrial production cost. These units are rectangular plates, each one being a flat tubular coil fitted between two flat parallel sheet metal plates having on their outer sides flat top raised bosses. These units are assembled together by the tops of the bosses so as to form an exchanger bank, each bank comprising two collectors to which the bank coils are tightly connected.

  1. Thulium heat sources for space power applications

    International Nuclear Information System (INIS)

    Alderman, C.J.

    1992-05-01

    Reliable power supplies for use in transportation and remote systems will be an important part of space exploration terrestrial activities. A potential power source is available in the rare earth metal, thulium. Fuel sources can be produced by activating Tm-169 targets in the space station reactor. The resulting Tm-170 heat sources can be used in thermoelectric generators to power instrumentation and telecommunications located at remote sites such as weather stations. As the heat source in a dynamic Sterling or Brayton cycle system, the heat source can provide a lightweight power source for rovers or other terrestrial transportation systems

  2. Solar-powered Rankine heat pump for heating and cooling

    Science.gov (United States)

    Rousseau, J.

    1978-01-01

    The design, operation and performance of a familyy of solar heating and cooling systems are discussed. The systems feature a reversible heat pump operating with R-11 as the working fluid and using a motor-driven centrifugal compressor. In the cooling mode, solar energy provides the heat source for a Rankine power loop. The system is operational with heat source temperatures ranging from 155 to 220 F; the estimated coefficient of performance is 0.7. In the heating mode, the vapor-cycle heat pump processes solar energy collected at low temperatures (40 to 80 F). The speed of the compressor can be adjusted so that the heat pump capacity matches the load, allowing a seasonal coefficient of performance of about 8 to be attained.

  3. Compact heat exchanger for power plants

    International Nuclear Information System (INIS)

    Kinnunen, L.

    2001-01-01

    Vahterus Oy, located at Kalanti, has manufactured heat exchangers since the beginning of 1990s. About 90% of the equipment produced are exported. In the PSHE (Plate and Shell) solution of the Vahterus heat exchanger the heat is transferred by round plated welded to form a compact package, which is assembled into a cylindrical steel casing. The heat exchanger contains no gaskets or soldered joints, which eliminates the leak risks. Traditional heat exchanges are usually operated at higher temperatures and pressures, but the heat transfer capacities of them are lower. Plate heat exchangers, on the other hand, are efficient, but the application range of them is narrow. Additionally, the rubber gasket of the heat exchange plates, sealing the joints of the heat exchanging plates, does not stand high pressures or temperatures, or corroding fluids. The new welded plate heat exchanger combine the pressure and temperature resistance of tube heat exchangers and the high heat exchange capacity of plate heat exchangers. The new corrosion resisting heat exchanger can be applied for especially hard conditions. The operating temperature range of the PSHE heat exchanger is - 200 - 900 deg C. The pressure resistance is as high as 100 bar. The space requirement of PSHE is only one tenth of the space requirement of traditional tube heat exchangers. Adjusting the number of heat exchanging plates can change the capacity of the heat exchanger. Power range of the heat exchanger can be as high as 80 MW. Due to the corrosion preventive construction and the small dimension the PSHE heat exchanger can be applied for refrigerators using ammonia as refrigerant. These kinds of new Vahterus heat exchangers are in use in 60 countries in more than 2000 refrigerators

  4. Waste Heat to Power Market Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Elson, Amelia [ICF International, Fairfax, VA (United States); Tidball, Rick [ICF International, Fairfax, VA (United States); Hampson, Anne [ICF International, Fairfax, VA (United States)

    2015-03-01

    Waste heat to power (WHP) is the process of capturing heat discarded by an existing process and using that heat to generate electricity. In the industrial sector, waste heat streams are generated by kilns, furnaces, ovens, turbines, engines, and other equipment. In addition to processes at industrial plants, waste heat streams suitable for WHP are generated at field locations, including landfills, compressor stations, and mining sites. Waste heat streams are also produced in the residential and commercial sectors, but compared to industrial sites these waste heat streams typically have lower temperatures and much lower volumetric flow rates. The economic feasibility for WHP declines as the temperature and flow rate decline, and most WHP technologies are therefore applied in industrial markets where waste heat stream characteristics are more favorable. This report provides an assessment of the potential market for WHP in the industrial sector in the United States.

  5. Heating of water by nuclear power stations

    International Nuclear Information System (INIS)

    1974-01-01

    The aim of this note is to examine: the thermal conditions of the Rhone in its present state; heating caused by the building of nuclear power stations; the main hydrobiological and ecological characteristics of the Rhone [fr

  6. Nuclear power for district heating

    International Nuclear Information System (INIS)

    Lyon, R.B.; Sochaski, R.O.

    1975-09-01

    Current district heating trends are towards an increasing use of electricity. This report concerns the evaluation of an alternative means of energy supply - the direct use of thermal energy from CANDU nuclear stations. The energy would be transmitted via a hot fluid in a pipeline over distances of up to 40 km. Advantages of this approach include a high utilization of primary energy, with a consequent reduction in installed capacity, and load flattening due to inherent energy storage capacity and transport delays. Disadvantages include the low load factors for district heating, the high cost of the distribution systems and the necessity for large-scale operation for economic viability. This requirement for large-scale operation from the beginning could cause difficulty in the implementation of the first system. Various approaches have been analysed and costed for a specific application - the supply of energy to a district heating load centre in Toronto from the location of the Pickering reactor station about 40 km away. (author)

  7. New waste heat district heating system with combined heat and power based on absorption heat exchange cycle in China

    International Nuclear Information System (INIS)

    Sun Fangtian; Fu Lin; Zhang Shigang; Sun Jian

    2012-01-01

    A new waste heat district heating system with combined heat and power based on absorption heat exchange cycle (DHAC) was developed to increase the heating capacity of combined heat and power (CHP) through waste heat recovery, and enhance heat transmission capacity of the existing primary side district heating network through decreasing return water temperature by new type absorption heat exchanger (AHE). The DHAC system and a conventional district heating system based on CHP (CDH) were analyzed in terms of both thermodynamics and economics. Compared to CDH, the DHAC increased heating capacity by 31% and increased heat transmission capacity of the existing primary side district heating network by 75%. The results showed that the exergetic efficiency of DHAC was 10.41% higher and the product exergy monetary cost was 36.6¥/GJ less than a CHD. DHAC is an effective way to increase thermal utilization factor of CHP, and to reduce district heating cost. - Highlights: ► Absorption heat pumps are used to recover waste heat in CHP. ► Absorption heat exchanger can reduce exergy loss in the heat transfer process. ► New waste heat heating system (DHAC) can increase heating capacity of CHP by 31%. ► DHAC can enhance heat transmission capacity of the primary pipe network by 75%. ► DHAC system has the higher exergetic efficiency and the better economic benefit.

  8. District heating in case of power failure

    International Nuclear Information System (INIS)

    Lauenburg, P.; Johansson, P.-O.; Wollerstrand, J.

    2010-01-01

    Power failures in combination with harsh weather conditions during recent years have led to an increased focus on a safe energy supply to our society. Many vital functions are dependent on electricity; e.g., lighting, telephony, medical equipment, lifts, alarm systems, payment, pumps for town's water and, perhaps the most critical of all, heating systems. In Sweden, district heating (DH) is the most common type of heating for buildings in town centres. Therefore, it is of great interest to investigate what happens in DH systems during a power failure. The present study shows that, by maintaining the DH production as well as the operation of the DH network, possibilities to supply connected buildings with space heat are surprisingly good. This is due to the fact that natural circulation will most often take place in radiator systems. In Sweden, and in many other countries, so-called indirect connection (heat supply across heat exchangers) of DH substations is applied. If a DH network operation can be maintained during a power failure, DH water will continue to pass the radiator system's heat exchanger (HEX), provided that the control valve does not close. The radiator circulation pump will stop, causing the radiator water to attain a relatively high temperature in the HEX, which promotes a natural circulation in the hydronic heating system, due to an increased water density differential at different temperatures. Several field tests and computer simulations have been performed and have displayed that almost all buildings can achieve a space heat supply corresponding to 40-80% of the amount prior to the interruption. A sufficient heat load in the DH network can be vital in certain cases: e.g., for 'island-operation' of an electric power plant to be performed during a power failure. Furthermore, for many combined heat and power stations, a requirement involves that the DH network continues to provide a heat sink when no other cooling is available. Based on the

  9. Combined heat and power in the City

    Energy Technology Data Exchange (ETDEWEB)

    Crafter, A. [Corporation of London (United Kingdom). Dept. of Technical Services

    2002-03-01

    This article reports on the development of a large-scale combined heat and power community energy scheme within the City of London. Supported by the Corporation of London and using its own buildings to provide the heating and cooling loads, the scheme has established a power plant close to Smithfield Meat Market and supplies district heating and chilled water for air conditioning to its own properties and some private customers in the nearby districts. Details are given of the power plant which is sited in a conservation area with limited access, the use of absorption chillers to produce the chilled water, the estimated amount of carbon dioxide emissions saved, and the financial benefits of the scheme.

  10. Heat recovery from nuclear power plants

    International Nuclear Information System (INIS)

    Safa, H.

    2012-01-01

    The thermodynamic efficiency of a standard Nuclear Power Plant (NPP) is around 33%. Therefore, about two third of the heat generated by the nuclear fuel is literally wasted in the environment. Given the fact that the steam coming out from the high pressure turbine is superheated, it could be advantageously used for non electrical applications, particularly for district heating. Considering the technological improvements achieved these last years in heat piping insulation, it is now perfectly feasible to envisage heat transport over quite long distances, exceeding 200 km, with affordable losses. Therefore, it could be energetically wise to revise the modifications required on present reactors to perform heat extraction without impeding the NPP operation. In this paper, the case of a French reactor is studied showing that a large fraction of the wasted nuclear heat can be actually recovered and transported to be injected in the heat distribution network of a large city. Some technical and economical aspects of nuclear district heating application are also discussed. (author)

  11. Cost allocation. Combined heat and power production

    International Nuclear Information System (INIS)

    Sidzikauskas, V.

    2002-01-01

    The benefits of Combined Heat and Power (CHP) generation are discussed. The include improvement in energy intensity of 1% by 2010, 85-90% efficiency versus 40-50% of condensation power and others. Share of CHP electricity production in ERRA countries is presented.Solutions for a development CHP cost allocation are considered. Conclusion are presented for CHP production cost allocation. (R.P.)

  12. Combined Heat and Power and Emissions Trading

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    The aim of this IEA Information Paper is to help policy makers and other stakeholders understand the challenges facing the incorporation of high efficiency combined heat and power (CHP) into greenhouse gas (GHG) Emissions Trading Schemes (ETSs) -- and to propose options for overcoming them.

  13. French nuclear power plants for heat generation

    International Nuclear Information System (INIS)

    Girard, Y.

    1984-01-01

    The considerable importance that France attributes to nuclear energy is well known even though as a result of the economic crisis and the energy savings it is possible to observe a certain downward trend in the rate at which new power plants are being started up. In July 1983, a symbolic turning-point was reached - at more than 10 thousand million kW.h nuclear power accounted, for the first time, for more than 50% of the total amount of electricity generated, or approx. 80% of the total electricity output of thermal origin. On the other hand, the direct contribution - excluding the use of electricity - of nuclear energy to the heat market in France remains virtually nil. The first part of this paper discusses the prospects and realities of the application, at low and intermediate temperatures, of nuclear heat in France, while the second part describes the French nuclear projects best suited to the heat market (excluding high temperatures). (author)

  14. Power generation from residual industrial heat

    International Nuclear Information System (INIS)

    Nguyen, T.Q.; Slawnwhite, J.D.; Boulama, K.Goni

    2010-01-01

    Industrial plants continuously reject large amounts of thermal energy through warm liquid or gaseous effluents during normal operation. These energy losses contribute to an inflation of production costs and also threaten the environment. This paper investigates methods of recovering the residual low grade thermal energy and converting it into higher quality mechanical energy using the thermodynamic Rankine cycle principle. For the temperature range of the available thermal energy, water was shown to be a poor working fluid for the conversion system, thus several potential working fluids, including ammonia, synthetic refrigerants, and organic compounds have been considered as alternatives. A comparative analysis led to the identification of different performance evaluation criteria. For example, the water-based Rankine cycle and, to a lesser extent, the ammonia-based Rankine cycle proved to be interesting when the power generation potential per unit working fluid mass flow rate was considered. On the other hand, Rankine-like cycles using dry hydrocarbon working fluids proved much more interesting in terms of energy conversion efficiency, as well as in terms of the net mechanical power generation potential for a given heat source. All performance indicators were low at low temperatures, and improved as the primary heat source was available at higher temperatures. This paper also discusses the influence of various external and internal operating parameters, such as heat source and heat sink temperatures, turbine and pump isentropic efficiencies and the addition of an internal heat exchanger on the overall performance of the energy recovery and conversion system.

  15. Heat pipe cooling of power processing magnetics

    Science.gov (United States)

    Hansen, I. G.; Chester, M.

    1979-01-01

    The constant demand for increased power and reduced mass has raised the internal temperature of conventionally cooled power magnetics toward the upper limit of acceptability. The conflicting demands of electrical isolation, mechanical integrity, and thermal conductivity preclude significant further advancements using conventional approaches. However, the size and mass of multikilowatt power processing systems may be further reduced by the incorporation of heat pipe cooling directly into the power magnetics. Additionally, by maintaining lower more constant temperatures, the life and reliability of the magnetic devices will be improved. A heat pipe cooled transformer and input filter have been developed for the 2.4 kW beam supply of a 30-cm ion thruster system. This development yielded a mass reduction of 40% (1.76 kg) and lower mean winding temperature (20 C lower). While these improvements are significant, preliminary designs predict even greater benefits to be realized at higher power. This paper presents the design details along with the results of thermal vacuum operation and the component performance in a 3 kW breadboard power processor.

  16. Profile Modifications Resulting from Early High-harmonic Fast Wave heating in NSTX

    International Nuclear Information System (INIS)

    Mendard, J.E.; LeBlanc, Wilson J.R.; Sabbagh, S.A.; Stutman, D.; Swain, D.W.

    2001-01-01

    Experiments have been performed in the National Spherical Torus Experiment (NSTX) to inject high harmonic fast wave (HHFW) power early during the plasma current ramp-up in an attempt to reduce the current penetration rate to raise the central safety factor during the flattop phase of the discharge. To date, up to 2 MW of HHFW power has been coupled to deuterium plasmas as early as t = 50 ms using the slowest interstrap phasing of k|| approximately equals 14 m(superscript)-1 (nf = 24). Antenna-plasma gap scans have been performed and find that for small gaps (5-8 cm), electron heating is observed with relatively small density rises and modest reductions in current penetration rate. For somewhat larger gaps (10-12 cm), weak electron heating is observed but with a spontaneous density rise at the plasma edge similar to that observed in NSTX H-modes. In the larger gap configuration, EFIT code reconstructions (without MSE [motional Stark effect]) find that resistive flux consumption is reduced as much as 30%, the internal inductance is maintained below 0.6 at 1 MA into the flattop, q(0) is increased significantly, and the MHD stability character of the discharges is strongly modified

  17. District heating and combined heat and power generation from biomass

    International Nuclear Information System (INIS)

    Veski, Rein

    1999-01-01

    An Altener programme seminar District Heating and Combined Heat and Power Generation from Biomass. Minitraining seminar and study tours and also Business forum, Exhibition and Short company presentations were held in Tallinn on March 21-23, 1999. The Seminar was organised by the VTT Energy, the Estonian Bioenergy Association and the Estonian Heat and Power Association in co-operation with the AFB-net. The Agricultural and Forestry Biomass Network (AFB-net) is part of the ALTENER programme. The Network aims at promoting and stimulating the implementation and commercial utilisation of energy from biomass and waste, through the initiation of business opportunities. This includes national and international co-operation and the exchange of the personnel. The Seminar was attended by consulting companies, scientists, municipal authorities and representatives of co-ordinating bodies engaged in renewable energy management as well as DH and CHP plant managers, equipment manufacturers and local energy planners from Finland, Estonia, Latvia, Lithuania, Sweden, Denmark, Belgium, Slovenia and Slovak Republic. At the Seminar minitraining issues were dealt with: the current situation and future trends in biomass DH in the Baltic Sea countries, and biomass DH and CHP in Eastern and Central Europe, planning and construction of biomass-based DH plants, biomass fuel procurement and handling technology, combustion technology, DH networks, financing of biomass projects and evaluating of projects, and case projects in Eastern and Central European countries. The following were presented: boilers with a capacity of 100 kW or more, stoker burners, wood and straw handling equipment, wood fuel harvesters, choppers, pelletisers, district heating pipelines and networks. (author)

  18. A heat receiver design for solar dynamic space power systems

    Science.gov (United States)

    Baker, Karl W.; Dustin, Miles O.; Crane, Roger

    1990-01-01

    An advanced heat pipe receiver designed for a solar dynamic space power system is described. The power system consists of a solar concentrator, solar heat receiver, Stirling heat engine, linear alternator and waste heat radiator. The solar concentrator focuses the sun's energy into a heat receiver. The engine and alternator convert a portion of this energy to electric power and the remaining heat is rejected by a waste heat radiator. Primary liquid metal heat pipes transport heat energy to the Stirling engine. Thermal energy storage allows this power system to operate during the shade portion of an orbit. Lithium fluoride/calcium fluoride eutectic is the thermal energy storage material. Thermal energy storage canisters are attached to the midsection of each heat pipe. The primary heat pipes pass through a secondary vapor cavity heat pipe near the engine and receiver interface. The secondary vapor cavity heat pipe serves three important functions. First, it smooths out hot spots in the solar cavity and provides even distribution of heat to the engine. Second, the event of a heat pipe failure, the secondary heat pipe cavity can efficiently transfer heat from other operating primary heat pipes to the engine heat exchanger of the defunct heat pipe. Third, the secondary heat pipe vapor cavity reduces temperature drops caused by heat flow into the engine. This unique design provides a high level of reliability and performance.

  19. Solar-powered turbocompressor heat pump system

    Science.gov (United States)

    Landerman, A.M.; Biancardi, F.R.; Melikian, G.; Meader, M.D.; Kepler, C.E.; Anderson, T.J.; Sitler, J.W.

    1982-08-12

    The turbocompressor comprises a power turbine and a compressor turbine having respective rotors and on a common shaft, rotatably supported by bearings. A first working fluid is supplied by a power loop and is expanded in the turbine. A second working fluid is compressed in the turbine and is circulated in a heat pump loop. A lubricant is mixed with the second working fluid but is excluded from the first working fluid. The bearings are cooled and lubricated by a system which circulates the second working fluid and the intermixed lubricant through the bearings. Such system includes a pump, a thermostatic expansion valve for expanding the working fluid into the space between the bearings, and a return conduit system for withdrawing the expanded working fluid after it passes through the bearings and for returning the working fluid to the evaporator. A shaft seal excludes the lubricant from the power turbine. The power loop includes a float operable by liquid working fluid in the condenser for controlling a recirculation valve so as to maintain a minimum liquid level in the condenser, while causing a feed pump to pump most of the working fluid into the vapor generator. The heat pump compressor loop includes a float in the condenser for operating and expansion valve to maintain a minimum liquid working fluid level in the condenser while causing most of the working fluid to be expanded into the evaporator.

  20. Integrated multiscale simulation of combined heat and power based district heating system

    International Nuclear Information System (INIS)

    Li, Peifeng; Nord, Natasa; Ertesvåg, Ivar Ståle; Ge, Zhihua; Yang, Zhiping; Yang, Yongping

    2015-01-01

    Highlights: • Simulation of power plant, district heating network and heat users in detail and integrated. • Coupled calculation and analysis of the heat and pressure losses of the district heating network. • District heating is not preferable for very low heat load due to relatively high heat loss. • Lower design supply temperatures of the district heating network give higher system efficiency. - Abstract: Many studies have been carried out separately on combined heat and power and district heating. However, little work has been done considering the heat source, the district heating network and the heat users simultaneously, especially when it comes to the heating system with large-scale combined heat and power plant. For the purpose of energy conservation, it is very important to know well the system performance of the integrated heating system from the very primary fuel input to the terminal heat users. This paper set up a model of 300 MW electric power rated air-cooled combined heat and power plant using Ebsilon software, which was validated according to the design data from the turbine manufacturer. Then, the model of heating network and heat users were developed based on the fundamental theories of fluid mechanics and heat transfer. Finally the combined heat and power based district heating system was obtained and the system performances within multiscale scope of the system were analyzed using the developed Ebsilon model. Topics with regard to the heat loss, the pressure drop, the pump power consumption and the supply temperatures of the district heating network were discussed. Besides, the operational issues of the integrated system were also researched. Several useful conclusions were drawn. It was found that a lower design primary supply temperature of the district heating network would give a higher seasonal energy efficiency of the integrated system throughout the whole heating season. Moreover, it was not always right to relate low design

  1. Method and means for heating buildings in a district heating system with waste heat from a thermal power plant

    International Nuclear Information System (INIS)

    Margen, P.H.E.

    1975-01-01

    The waste heat from a thermal power plant is transported through a municipal heating network to a plurality of buildings to be heated. The quantity of heat thus supplied to the buildings is higher than that required for the heating of the buildings. The excess heat is released from the buildings to the atmosphere in the form of hot air

  2. 21 CFR 890.5950 - Powered heating unit.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered heating unit. 890.5950 Section 890.5950...) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5950 Powered heating unit. (a) Identification. A powered heating unit is a device intended for medical purposes that...

  3. 21 CFR 890.5740 - Powered heating pad.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered heating pad. 890.5740 Section 890.5740...) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5740 Powered heating pad. (a) Identification. A powered heating pad is an electrical device intended for medical purposes...

  4. Combined heat and power solar system

    International Nuclear Information System (INIS)

    Anon

    2000-01-01

    An Australian-designed photovoltaic (PV) power system that also supplies hot water is close to commercial release. PVs have been around for decades and solar concentrators have been efficiently heating water for nearly a century. The Australian National University, Department of Engineering - Centre for Sustainable Energy systems (CSES), has designed a domestic scale modular system that not only generates electricity but also provides concentrated thermal energy to heat water for a Solahart hot water system and is designed to be deployed into small to medium scale applications such as hospitals, schools and dwellings with an easily assembled galvanised steel frame. A market research was carried out and is envisaged that at least 7,500 units will be installed annually by the year 2005 and up to 25,000 units by 2008

  5. Technology Roadmaps: Bioenergy for Heat and Power

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    The Technology Roadmap Bioenergy for Heat and Power highlights the importance of bioenergy in providing heat in the buildings sector and in industry, and shows what contribution it could make to meeting steadlily growing world electricity demand. The critical role of sustainability as well as the importance of international trade in meeting the projected demand for bioenergy, are highlighted in the roadmap, as well as the need for large-scale biomass plants in providing The roadmap identifies key actions by different stakeholders in the bioenergy sector, and sets out milestones for technology development in order to achieve a doubling of global bioenergy supply by 2050. It addresses the need for further R&D efforts, highlights measures to ensure sustainability of biomass production, and underlines the need for international collaboration to enhance the production and use of sustainable, modern bioenergy in different world regions.

  6. Technology Roadmaps: Bioenergy for Heat and Power

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-08-01

    The Technology Roadmap Bioenergy for Heat and Power highlights the importance of bioenergy in providing heat in the buildings sector and in industry, and shows what contribution it could make to meeting steadlily growing world electricity demand. The critical role of sustainability as well as the importance of international trade in meeting the projected demand for bioenergy, are highlighted in the roadmap, as well as the need for large-scale biomass plants in providing The roadmap identifies key actions by different stakeholders in the bioenergy sector, and sets out milestones for technology development in order to achieve a doubling of global bioenergy supply by 2050. It addresses the need for further R&D efforts, highlights measures to ensure sustainability of biomass production, and underlines the need for international collaboration to enhance the production and use of sustainable, modern bioenergy in different world regions.

  7. Nuclear power generation and global heating

    International Nuclear Information System (INIS)

    Taboada, Horacio

    1999-01-01

    The Professionals Association and Nuclear Activity of National Atomic Energy Commission (CNEA) are following with great interest the worldwide discussions on global heating and the role that nuclear power is going to play. The Association has an active presence, as part of the WONUC (recognized by the United Nations as a Non-Governmental Organization) in the COP4, which was held in Buenos Aires in November 1998. The environmental problems are closely related to human development, the way of power production, the techniques for industrial production and exploitation fields. CO 2 is the most important gas with hothouse effects, responsible of progressive climatic changes, as floods, desertification, increase of average global temperature, thermal expansion in seas and even polar casks melting and ice falls. The consequences that global heating will have on the life and economy of human society cannot be sufficiently emphasized, great economical impact, destruction of ecosystems, loss of great coast areas and complete disappearance of islands owing to water level rise. The increase of power retained in the atmosphere generates more violent hurricanes and storms. In this work, the topics presented in the former AATN Meeting is analyzed in detail and different technological options and perspectives to mitigate CO 2 emission, as well as economical-financial aspects, are explored. (author)

  8. Optimization of heat supply systems employing nuclear power plants

    International Nuclear Information System (INIS)

    Urbanek, J.

    1988-01-01

    Decision making on the further development of heat supply systems requires optimization of the parameters. In particular, meeting the demands of peak load ranges is of importance. The heat supply coefficient α and the annual utilization of peak load equipment τ FS have been chosen as the characteristic quantities to describe them. The heat price at the consumer, C V , offers as the optimization criterion. The transport distance, temperature spread of the heating water, and different curves of annual variation of heat consumption on heat supply coefficient and heat price at the consumer. A comparison between heat supply by nuclear power plants and nuclear heating stations verifies the advantage of combined heat and power generation even with longer heat transport distances as compared with local heat supply by nuclear district heating stations based on the criterion of minimum employment of peak load boilers. (author)

  9. Heat savings in buildings in a 100% renewable heat and power system in Denmark with different shares of district heating

    DEFF Research Database (Denmark)

    Zvingilaite, Erika; Balyk, Olexandr

    2014-01-01

    levels of heat savings, which can be implemented by reducing heat transmission losses through building elements and by installing ventilation systems with heat recovery, in different future Danish heat and power system scenarios. Today almost 50% of heat demand in Denmark is covered by district heating......The paper examines implementation of heat saving measures in buildings in 2050, under the assumption that heat and power supply comes solely from renewable resources in Denmark.Balmorel – a linear optimisation model of heat and power sectors in Denmark is used for investigating economically viable....... A further expansion of district heating network in Denmark is assessed and penetration of heat savings is analysed in this context.If all heat saving measures, included in the model, are implemented, heat demand in Danish buildings in 2050 could be reduced by around 40%. Results show that it is cost...

  10. Optimum heat power cycles for specified boundary conditions

    International Nuclear Information System (INIS)

    Ibrahim, O.M.; Klein, S.A.; Mitchell, J.W.

    1991-01-01

    In this paper optimization of the power output of Carnot and closed Brayton cycles is considered for both finite and infinite thermal capacitance rates of the external fluid streams. The method of Lagrange multipliers is used to solve for working fluid temperatures that yield maximum power. Analytical expressions for the maximum power and the cycle efficiency at maximum power are obtained. A comparison of the maximum power from the two cycles for the same boundary conditions, i.e., the same heat source/sink inlet temperatures, thermal capacitance rates, and heat exchanger conductances, shows that the Brayton cycle can produce more power than the Carnot cycle. This comparison illustrates that cycles exist that can produce more power than the Carnot cycle. The optimum heat power cycle, which will provide the upper limit of power obtained from any thermodynamic cycle for specified boundary conditions and heat exchanger conductances is considered. The optimum heat power cycle is identified by optimizing the sum of the power output from a sequence of Carnot cycles. The shape of the optimum heat power cycle, the power output, and corresponding efficiency are presented. The efficiency at maximum power of all cycles investigated in this study is found to be equal to (or well approximated by) η = 1 - sq. root T L.in /φT H.in where φ is a factor relating the entropy changes during heat rejection and heat addition

  11. The contribution of radio-frequency rectification to field-aligned losses of high-harmonic fast wave power to the divertor in the National Spherical Torus eXperiment

    Energy Technology Data Exchange (ETDEWEB)

    Perkins, R. J., E-mail: rperkins@pppl.gov; Hosea, J. C.; Jaworski, M. A.; Diallo, A.; Bell, R. E.; Bertelli, N.; Gerhardt, S.; Kramer, G. J.; LeBlanc, B. P.; Phillips, C. K.; Podestà, M.; Roquemore, L.; Taylor, G.; Wilson, J. R. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Ahn, J.-W.; Gray, T. K. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); McLean, A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Sabbagh, S. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)

    2015-04-15

    The National Spherical Torus eXperiment (NSTX) can exhibit a major loss of high-harmonic fast wave (HHFW) power along scrape-off layer (SOL) field lines passing in front of the antenna, resulting in bright and hot spirals on both the upper and lower divertor regions. One possible mechanism for this loss is RF sheaths forming at the divertors. Here, we demonstrate that swept-voltage Langmuir probe characteristics for probes under the spiral are shifted relative to those not under the spiral in a manner consistent with RF rectification. We estimate both the magnitude of the RF voltage across the sheath and the sheath heat flux transmission coefficient in the presence of the RF field. Although precise comparison between the computed heat flux and infrared (IR) thermography cannot yet be made, the computed heat deposition compares favorably with the projections from IR camera measurements. The RF sheath losses are significant and contribute substantially to the total SOL losses of HHFW power to the divertor for the cases studied. This work will guide future experimentation on NSTX-U, where a wide-angle IR camera and a dedicated set of coaxial Langmuir probes for measuring the RF sheath voltage directly will quantify the contribution of RF sheath rectification to the heat deposition from the SOL to the divertor.

  12. Heat and power from MicroGen

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1999-10-01

    This paper reports on the design of a domestic gas-fired cogeneration system developed to replace the central heating boiler. Technical details of the MicroGen demonstration unit are given, and the use of a Linear Free Piston Stirling Engine as the prime mover, and the results of modelling studies of energy demand indicating cost savings compared to conventional boilers are discussed. The enhancement of the benefits of micro-cogeneration through use of thermal and power storage and energy demand management, and the impact of micro-cogeneration on energy use in the home are considered. The UK and European Commission's targets for increased cogeneration capacity are noted.

  13. Wind power integration using individual heat pumps – Analysis of different heat storage options

    DEFF Research Database (Denmark)

    Hedegaard, Karsten; Mathiesen, Brian Vad; Lund, Henrik

    2012-01-01

    Significant installations of individual heat pumps are expected in future energy systems due to their economic competitiveness. This case study of the Danish energy system in 2020 with 50% wind power shows that individual heat pumps and heat storages can contribute to the integration of wind power....... Heat accumulation tanks and passive heat storage in the construction are investigated as two alternative storage options in terms of their ability to increase wind power utilisation and to provide cost-effective fuel savings. Results show that passive heat storage can enable equivalent to larger...... reductions in excess electricity production and fuel consumption than heat accumulation tanks. Moreover, passive heat storage is found to be significantly more cost-effective than heat accumulation tanks. In terms of reducing fuel consumption of the energy system, the installation of heat pumps is the most...

  14. Research of waste heat energy efficiency for absorption heat pump recycling thermal power plant circulating water

    Science.gov (United States)

    Zhang, Li; Zhang, Yu; Zhou, Liansheng; E, Zhijun; Wang, Kun; Wang, Ziyue; Li, Guohao; Qu, Bin

    2018-02-01

    The waste heat energy efficiency for absorption heat pump recycling thermal power plant circulating water has been analyzed. After the operation of heat pump, the influences on power generation and heat generation of unit were taken into account. In the light of the characteristics of heat pump in different operation stages, the energy efficiency of heat pump was evaluated comprehensively on both sides of benefits belonging to electricity and benefits belonging to heat, which adopted the method of contrast test. Thus, the reference of energy efficiency for same type projects was provided.

  15. THERMOCHEMICAL HEAT STORAGE FOR CONCENTRATED SOLAR POWER

    Energy Technology Data Exchange (ETDEWEB)

    PROJECT STAFF

    2011-10-31

    Thermal energy storage (TES) is an integral part of a concentrated solar power (CSP) system. It enables plant operators to generate electricity beyond on sun hours and supply power to the grid to meet peak demand. Current CSP sensible heat storage systems employ molten salts as both the heat transfer fluid and the heat storage media. These systems have an upper operating temperature limit of around 400 C. Future TES systems are expected to operate at temperatures between 600 C to 1000 C for higher thermal efficiencies which should result in lower electricity cost. To meet future operating temperature and electricity cost requirements, a TES concept utilizing thermochemical cycles (TCs) based on multivalent solid oxides was proposed. The system employs a pair of reduction and oxidation (REDOX) reactions to store and release heat. In the storage step, hot air from the solar receiver is used to reduce the oxidation state of an oxide cation, e.g. Fe3+ to Fe2+. Heat energy is thus stored as chemical bonds and the oxide is charged. To discharge the stored energy, the reduced oxide is re-oxidized in air and heat is released. Air is used as both the heat transfer fluid and reactant and no storage of fluid is needed. This project investigated the engineering and economic feasibility of this proposed TES concept. The DOE storage cost and LCOE targets are $15/kWh and $0.09/kWh respectively. Sixteen pure oxide cycles were identified through thermodynamic calculations and literature information. Data showed the kinetics of re-oxidation of the various oxides to be a key barrier to implementing the proposed concept. A down selection was carried out based on operating temperature, materials costs and preliminary laboratory measurements. Cobalt oxide, manganese oxide and barium oxide were selected for developmental studies to improve their REDOX reaction kinetics. A novel approach utilizing mixed oxides to improve the REDOX kinetics of the selected oxides was proposed. It partially

  16. Low grade waste heat recovery using heat pumps and power cycles

    International Nuclear Information System (INIS)

    Bor, D.M. van de; Infante Ferreira, C.A.; Kiss, Anton A.

    2015-01-01

    Thermal energy represents a large part of the global energy usage and about 43% of this energy is used for industrial applications. Large amounts are lost via exhaust gases, liquid streams and cooling water while the share of low temperature waste heat is the largest. Heat pumps upgrading waste heat to process heat and cooling and power cycles converting waste heat to electricity can make a strong impact in the related industries. The potential of several alternative technologies, either for the upgrading of low temperature waste heat such as compression-resorption, vapor compression and trans-critical heat pumps, or for the conversion of this waste heat by using organic Rankine, Kalina and trilateral cycle engines, are investigated with regards to energetic and economic performance by making use of thermodynamic models. This study focuses on temperature levels of 45–60 °C as at this temperature range large amounts of heat are rejected to the environment but also investigates the temperature levels for which power cycles become competitive. The heat pumps deliver 2.5–11 times more energy value than the power cycles in this low temperature range at equal waste heat input. Heat engines become competitive with heat pumps at waste heat temperatures at 100 °C and above. - Highlights: • Application of heat pump technology for heating and cooling. • Compression resorption heat pumps operating with large glides approaching 100 K. • Compression-resorption heat pumps with wet compression. • Potential to convert Industrial waste heat to power or high grade heat. • Comparison between low temperature power cycles and heat pumps

  17. Heat-Pipe-Associated Localized Thermoelectric Power Generation System

    Science.gov (United States)

    Kim, Pan-Jo; Rhi, Seok-Ho; Lee, Kye-Bock; Hwang, Hyun-Chang; Lee, Ji-Su; Jang, Ju-Chan; Lee, Wook-Hyun; Lee, Ki-Woo

    2014-06-01

    The present study focused on how to improve the maximum power output of a thermoelectric generator (TEG) system and move heat to any suitable space using a TEG associated with a loop thermosyphon (loop-type heat pipe). An experimental study was carried out to investigate the power output, the temperature difference of the thermoelectric module (TEM), and the heat transfer performance associated with the characteristic of the researched heat pipe. Currently, internal combustion engines lose more than 35% of their fuel energy as recyclable heat in the exhaust gas, but it is not easy to recycle waste heat using TEGs because of the limited space in vehicles. There are various advantages to use of TEGs over other power sources, such as the absence of moving parts, a long lifetime, and a compact system configuration. The present study presents a novel TEG concept to transfer heat from the heat source to the sink. This technology can transfer waste heat to any location. This simple and novel design for a TEG can be applied to future hybrid cars. The present TEG system with a heat pipe can transfer heat and generate power of around 1.8 V with T TEM = 58°C. The heat transfer performance of a loop-type heat pipe with various working fluids was investigated, with water at high heat flux (90 W) and 0.05% TiO2 nanofluid at low heat flux (30 W to 70 W) showing the best performance in terms of power generation. The heat pipe can transfer the heat to any location where the TEM is installed.

  18. Scavenged body heat powered infusion pump

    International Nuclear Information System (INIS)

    Bell, Alexander; Ehringer, William D; McNamara, Shamus

    2013-01-01

    An infusion pump powered by body heat is investigated in this paper, with the goal of addressing the needs of dermal wound healing. The infusion pump incorporates a Knudsen gas pump, a type of thermally driven pump, to pneumatic push the pharmaceutical agent from a reservoir. Two designs are considered: an integrated pump and reservoir, and a design with cascaded pump and reservoir. Thermal models are developed for both pumps, and the simulations agree well with the experimental results. The integrated pump and reservoir design uses hydrophobic materials to prevent a flow from occurring unless the infusion pump is placed on a human body. Flow rates in the µL min −1 range for the integrated pump and reservoir, and approximately 70 µL min −1 for the cascaded pump were obtained. The dynamic behavior of the cascaded pump is described based on the thermal models. Multiple copies of the cascaded pump are easily made in series or parallel, to increase either the pressure or the flow rate. The flow rate of multiple pumps in series does not change, and the pressure of multiple pumps in parallel does not change. (paper)

  19. Modular control of fusion power heating applications

    International Nuclear Information System (INIS)

    Demers, D. R.

    2012-01-01

    This work is motivated by the growing demand for auxiliary heating on small and large machines worldwide. Numerous present and planned RF experiments (EBW, Lower Hybrid, ICRF, and ECH) are increasingly complex systems. The operational challenges are indicative of a need for components of real-time control that can be implemented with a moderate amount of effort in a time- and cost-effective fashion. Such a system will improve experimental efficiency, enhance experimental quality, and expedite technological advancements. The modular architecture of this control-suite serves multiple purposes. It facilitates construction on various scales from single to multiple controller systems. It enables expandability of control from basic to complex via the addition of modules with varying functionalities. It simplifies the control implementation process by reducing layers of software and electronic development. While conceived with fusion applications in mind, this suite has the potential to serve a broad range of scientific and industrial applications. During the Phase-I research effort we established the overall feasibility of this modular control-suite concept. We developed the fundamental modules needed to implement open-loop active-control and demonstrated their use on a microwave power deposition experiment

  20. Alfa-Laval plate heat exchangers for the power industries

    International Nuclear Information System (INIS)

    Kitae, Junnosuke; Mtsuura, Kazuyuki

    1979-01-01

    Within power-generating plants, the transfer and conversion of heat energy of very large quantity are carried out in the process of energy conversion, accordingly the importance of heat exchangers is very high. Heretofore, multi-tube heat exchangers have been used mostly, but Alfa-Laval group developed the heat exchanger with very high efficiency to incorporate it effectively into a power-generating plant. In this plate type heat exchanger, the heat transfer efficiency is very high, and the quantity of stagnation is small as it is compact, consequently it is suitable to the secondary cooling for power-generating plant or the heat exchange of high-priced liquid heat media such as heavy water. Originally, plate type heat exchangers were used for food and chemical industries, therefore the prevention of mixing two liquids, sanitary construction, and corrosion resistance were required. Then they were adopted in iron and steel industry, and large thermal load, large heat transfer area and corrosion resistance to sea water were required. They were adopted in a nuclear power plant for the first time in 1964. In this heat exchanger, channels are formed with corrugated metal sheets, and titanium, stainless steels, Incoloy, Hastelloy and others are used as occasion demands. The Alfa-Laval heat exchangers and their features are explained. (Kako, I.)

  1. Heat Recovery From Tail Gas Incineration To Generate Power

    Energy Technology Data Exchange (ETDEWEB)

    Tawfik, Tarek

    2010-09-15

    Many industrial processes result in tail gas wastes that must be flared or incinerated to abide with environmental guidelines. Tail gas incineration occurs in several chemical processes resulting in high-temperature exhaust gas that simply go to the stack, thus wasting all that valuable heat! This paper discusses useful heat recovery and electric power generation utilizing available heat in exhaust gas from tail gas incinerators. This heat will be recovered in a waste-heat recovery boiler that will produce superheated steam to expand in a steam turbine to generate power. A detailed cost estimate is presented.

  2. In-volume heating using high-power laser diodes

    NARCIS (Netherlands)

    Denisenkov, V.S.; Kiyko, V.V.; Vdovin, G.V.

    2015-01-01

    High-power lasers are useful instruments suitable for applications in various fields; the most common industrial applications include cutting and welding. We propose a new application of high-power laser diodes as in-bulk heating source for food industry. Current heating processes use surface

  3. District heating by the Bohunice nuclear power plant

    International Nuclear Information System (INIS)

    Metke, E.; Skvarka, P.

    1984-01-01

    Technical and economical aspects of district heating by the electricity generating nuclear plants in Czechoslovakia are discussed. As a first stage of the project, 240 MW thermal power will be supplied using bleeding lines steam from the B-2 nuclear power plant at Jaslovske Bohunice to heat up water at a central station to 130 grad C. The maximal thermal power that can be produced for district heating by WWER type reactors with regular condensation turbines is estimated to be: 465 MW for a WWER-440 reactor with two 220 MWe turbines and 950 MW for a WWER-1000 reactor with a Skoda made 1000 MWe turbine using a three-stage scheme to heat up water from 60 grad C to 150 grad C. The use of satelite heating turbines connected to the steam collector is expected to improve the efficiency. District heating needs will de taken into account for siting of the new power plants

  4. High-power condensation turbine application to district heating

    International Nuclear Information System (INIS)

    Virchenko, M.A.; Arkad'ev, B.A.; Ioffe, V.Yu.

    1982-01-01

    In general outline the role of condensation turbines in NPP district heating is considered. The expediency of expansion of central heating loading of turbines of operating as well as newly designed condensation power plants on the basis of the WWER-1000-type reactors is shown. The principle heat flowsheet of the 1000 MW power turbine is given. An advantage in using turbines with uncontrolled steam bleeding is pointed out [ru

  5. A thermosyphon heat pipe cooler for high power LEDs cooling

    Science.gov (United States)

    Li, Ji; Tian, Wenkai; Lv, Lucang

    2016-08-01

    Light emitting diode (LED) cooling is facing the challenge of high heat flux more seriously with the increase of input power and diode density. The proposed unique thermosyphon heat pipe heat sink is particularly suitable for cooling of high power density LED chips and other electronics, which has a heat dissipation potential of up to 280 W within an area of 20 mm × 22 mm (>60 W/cm2) under natural air convection. Meanwhile, a thorough visualization investigation was carried out to explore the two phase flow characteristics in the proposed thermosyphon heat pipe. Implementing this novel thermosyphon heat pipe heat sink in the cooling of a commercial 100 W LED integrated chip, a very low apparent thermal resistance of 0.34 K/W was obtained under natural air convection with the aid of the enhanced boiling heat transfer at the evaporation side and the enhanced natural air convection at the condensation side.

  6. Heat pipe nuclear reactor for space power

    Science.gov (United States)

    Koening, D. R.

    1976-01-01

    A heat-pipe-cooled nuclear reactor has been designed to provide 3.2 MWth to an out-of-core thermionic conversion system. The reactor is a fast reactor designed to operate at a nominal heat-pipe temperature of 1675 K. Each reactor fuel element consists of a hexagonal molybdenum block which is bonded along its axis to one end of a molybdenum/lithium-vapor heat pipe. The block is perforated with an array of longitudinal holes which are loaded with UO2 pellets. The heat pipe transfers heat directly to a string of six thermionic converters which are bonded along the other end of the heat pipe. An assembly of 90 such fuel elements forms a hexagonal core. The core is surrounded by a thermal radiation shield, a thin thermal neutron absorber, and a BeO reflector containing boron-loaded control drums.

  7. Dynamic Performance of the Standalone Wind Power Driven Heat Pump

    OpenAIRE

    H. Li; P.E. Campana; S. Berretta; Y. Tan; J. Yan

    2016-01-01

    Reducing energy consumption and increasing use of renewable energyin the building sector arecrucial to the mitigation of climate change. Wind power driven heat pumps have been considered as a sustainable measure to supply heat for detached houses, especially those that even don’t have access to the grid. This work is to investigate the dynamic performance of a heat pump system directly driven by a wind turbine. The heat demand of a detached single family house was simulated in details. Accord...

  8. Method of calculating heat transfer in furnaces of small power

    Directory of Open Access Journals (Sweden)

    Khavanov Pavel

    2016-01-01

    Full Text Available This publication presents the experiences and results of generalization criterion equation of importance in the analysis of the processes of heat transfer and thermal calculations of low-power heat generators cooled combustion chambers. With generalizing depending estimated contribution of radiation and convective heat transfer component in the complex for the combustion chambers of small capacity boilers. Determined qualitative and quantitative dependence of the integrated radiative-convective heat transfer from the main factors working combustion chambers of small volume.

  9. Recent Fast Wave Coupling and Heating Studies on NSTX, with Possible Implications for ITER

    International Nuclear Information System (INIS)

    Hosea, J.C.; Bell, R.E.; Feibush, E.; Harvey, R.W.; Jaeger, E.F.; LeBlanc, B.P; Maingi, R.; Phillips, C.K.; Roquemore, L.; Ryan, P.M.; Taylor, G.; Tritz, K.; Valeo, E.J.; Wilgen, J.; Wilson, J.R.

    2009-01-01

    The goal of the high harmonic fast wave (HHFW) research on NSTX is to maximize the coupling of RF power to the core of the plasma by minimizing the coupling of RF power to edge loss processes. HHFW core plasma heating efficiency in helium and deuterium L-mode discharges is found to improve markedly on NSTX when the density 2 cm in front of the antenna is reduced below that for the onset of perpendicular wave propagation (n onset ∝ B*k # parallel# 2 /ω). In NSTX, the observed RF power losses in the plasma edge are driven in the vicinity of the antenna as opposed to resulting from multi-pass edge damping. PDI surface losses through ion-electron collisions are estimated to be significant. Recent spectroscopic measurements suggest that additional PDI losses could be caused by the loss of energetic edge ions on direct loss orbits and perhaps result in the observed clamping of the edge rotation. Initial deuterium H-mode heating studies reveal that core heating is degraded at lower k φ (- 8 m -1 relative to 13 m -1 ) as for the Lmode case at elevated edge density. Fast visible camera images clearly indicate that a major edge loss process is occurring from the plasma scrape off layer (SOL) in the vicinity of the antenna and along the magnetic field lines to the lower outer divertor plate. Large type I ELMs, which are observed at both k φ values, appear after antenna arcs caused by precursor blobs, low level ELMs, or dust. For large ELMs without arcs, the source reflection coefficients rise on a 0.1 ms time scale, which indicates that the time derivative of the reflection coefficient can be used to discriminate between arcs and ELMs.

  10. Effect of finite heat input on the power performance of micro heat engines

    International Nuclear Information System (INIS)

    Khu, Kerwin; Jiang, Liudi; Markvart, Tom

    2011-01-01

    Micro heat engines have attracted considerable interest in recent years for their potential exploitation as micro power sources in microsystems and portable devices. Thermodynamic modeling can predict the theoretical performance that can be potentially achieved by micro heat engine designs. An appropriate model can not only provide key information at the design stage but also indicate the potential room for improvement in existing micro heat engines. However, there are few models reported to date which are suitable for evaluating the power performance of micro heat engines. This paper presents a new thermodynamic model for determining the theoretical limit of power performance of micro heat engines with consideration to finite heat input and heat leakage. By matching the model components to those of a representative heat engine layout, the theoretical power, power density, and thermal efficiency achievable for a micro heat engine can be obtained for a given set of design parameters. The effects of key design parameters such as length and thermal conductivity of the engine material on these theoretical outputs are also investigated. Possible trade-offs among these performance objectives are discussed. Performance results derived from the developed model are compared with those of a working micro heat engine (P3) as an example. -- Highlights: → Thermodynamic model for micro heat engines. → Effect of different parameters on potential performance. → Tradeoffs for determining optimal size of micro engines.

  11. Influence of wind power, plug-in electric vehicles, and heat storages on power system investments

    International Nuclear Information System (INIS)

    Kiviluoma, Juha; Meibom, Peter

    2010-01-01

    Due to rising fuel costs, the substantial price for CO 2 emissions and decreasing wind power costs, wind power might become the least expensive source of power for an increasing number of power systems. This poses the questions of how wind power might change optimal investments in other forms of power production and what kind of means could be used to increase power system flexibility in order to incorporate the variable power production from wind power in a cost-effective manner. We have analysed possible effects using an investment model that combines heat and power production and simulates electric vehicles. The model runs in an hourly time scale in order to accommodate the impact of variable power production from wind power. Electric vehicles store electricity for later use and can thus serve to increase the flexibility of the power system. Flexibility can also be upgraded by using heat storages with heat from heat pumps, electric heat boilers and combined heat and power (CHP) plants. Results show that there is great potential for additional power system flexibility in the production and use of heat. (author)

  12. Solar Powered Heat Control System for Cars

    OpenAIRE

    Abin John; Jithin Thomas

    2014-01-01

    It takes times for an air-conditioner to effectively start cooling the passenger compartment in the car. So the passenger of the car will feel the heat in the car extremely before the air-conditioner fully cooling the interior of the car. Excessive heat can also damage an automobile's interior as well as personal property kept in the passenger compartment. So, a system to reduce this excessive heat by pumping out hot air and allowing cooler ambient air to enter the car by mean...

  13. Device for district heating with utilization of waste heat from power plants

    International Nuclear Information System (INIS)

    Korek, J.

    1976-01-01

    In order to utilize the waste heat developing in power plants - especially in nuclear power plants - the author suggests to lead the waste heat of the coolers for oil (which the bearings are lubricated with), hydrogen (which serves for the stator rotor-cooling), and the stator cooling water to the circulating district heating water and to arrange these heat exchangers one behind another or parallel to each other in the water circuit of the district heating system. The oil cooler of the engine transformer is also connected with the circulation of the district heating water. The runback water of the district heating network could thus be heated from approx. 40 0 C up to 65 0 C. (UA) [de

  14. Heat extraction from turbines of Czechoslovak nuclear power plants for district heating

    International Nuclear Information System (INIS)

    Drahy, J.

    1985-01-01

    Two design are described of SKODA extraction turbines for Czechoslovak nuclear power plants with WWER-440 and WWER-1000 reactors. 220 MW steam turbines were originally designed as pure condensation turbines with uncontrolled steam extraction. Optimal ways are now being sought for their use for heating hot water for district heating. For district heating of the town of Trnava, the nuclear power plant at Jaslovske Bohunice will provide a two-step heating of water from 70 to 120 degC with a heat supply of 60 MW th from one turbine unit. The ratio of obtained heat power to lost electric power is 5.08. Investigations showed the possibility of extracting 85 MW th of heat from uncontrolled steam extraction, this at three-step water heating from 60 to 145 degC, the ratio of gained and lost power being 7.14. Information is presented on the SKODA 220 MW turbine with steam extraction for heat supply purposes and on the 1000 MW turbine with 893 MW th heat extraction. The specifications of both types are given. (Pu)

  15. Advances in Nuclear Power Process Heat Applications

    International Nuclear Information System (INIS)

    2012-05-01

    Following an IAEA coordinated research project, this publication compiles the findings of research and development activities related to practical nuclear process heat applications. An overview of current progress on high temperature gas cooled reactors coupling schemes for different process heat applications, such as hydrogen production and desalination is included. The associated safety aspects are also highlighted. The summary report documents the results and conclusions of the project.

  16. Consistency among integral measurements of aggregate decay heat power

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, H.; Sagisaka, M.; Oyamatsu, K.; Kukita, Y. [Nagoya Univ. (Japan)

    1998-03-01

    Persisting discrepancies between summation calculations and integral measurements force us to assume large uncertainties in the recommended decay heat power. In this paper, we develop a hybrid method to calculate the decay heat power of a fissioning system from those of different fissioning systems. Then, this method is applied to examine consistency among measured decay heat powers of {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U and {sup 239}Pu at YAYOI. The consistency among the measured values are found to be satisfied for the {beta} component and fairly well for the {gamma} component, except for cooling times longer than 4000 s. (author)

  17. Utilization of waste heat from nuclear power plants in agriculture

    International Nuclear Information System (INIS)

    Horacek, P.

    1981-01-01

    The development of nuclear power will result in the relative and absolute increase in the amount of waste heat which can be used in agriculture for heating greenhouses, open spaces, for fish breeding in heated water, for growing edible mushrooms, growing algae, for frost protection of orchards, air conditioning of buildings for breeding livestock and poultry, and for other purposes. In addition of the positive effect of waste heat, the danger increases of disease, weeds and pests. Pilot plant installations should be build in Czechoslovakia for testing the development of waste heat utilization. (Ha)

  18. Nuclear steam turbines for power production in combination with heating

    International Nuclear Information System (INIS)

    Frilund, B.; Knudsen, K.

    1977-01-01

    The general operating conditions for nuclear steam turbines in district heating system are briefly outlined. The turbine plant can consist of essentially the same types of machines as in conventional district heating systems. Some possible arrangements of back-pressure turbines, back-pressure turbines with condensing tails, or condensing turbines with heat extraction are considered for nuclear power and heat stations. Principles of control for hot water temperature and electrical output are described. Optimization of the plant, considering parallel variations during the year between heat load, cooling water temperature, and required outgoing temperature is discussed. (U.K.)

  19. Transwaal - economic district heat from the Beznau nuclear power station

    International Nuclear Information System (INIS)

    Schatzmann, G.

    1986-01-01

    Initial study phases of the Transwaal project for distribution of heat from the Beznau nuclear power station via pipe lines to Aare and Limmat valley regions in Switzerland are presented. 500 MW heat availability through heat exchangers providing forward flow water temperature of 120 0 C, pipe line network and pumping station aspects, and the system energy flow diagram, are described. Considerations based on specific energy requirements in the year 2000 including alternative schemes showed economic viability. Investment and consumer costs and savings compared with oil and gas heating are discussed. Heat supply is guaranteed well into the 21st century and avoids environmental disadvantages. (H.V.H.)

  20. Combined Heat and Power Dispatch Considering Heat Storage of Both Buildings and Pipelines in District Heating System for Wind Power Integration

    Directory of Open Access Journals (Sweden)

    Ping Li

    2017-06-01

    Full Text Available The strong coupling between electric power and heat supply highly restricts the electric power generation range of combined heat and power (CHP units during heating seasons. This makes the system operational flexibility very low, which leads to heavy wind power curtailment, especially in the region with a high percentage of CHP units and abundant wind power energy such as northeastern China. The heat storage capacity of pipelines and buildings of the district heating system (DHS, which already exist in the urban infrastructures, can be exploited to realize the power and heat decoupling without any additional investment. We formulate a combined heat and power dispatch model considering both the pipelines’ dynamic thermal performance (PDTP and the buildings’ thermal inertia (BTI, abbreviated as the CPB-CHPD model, emphasizing the coordinating operation between the electric power and district heating systems to break the strong coupling without impacting end users’ heat supply quality. Simulation results demonstrate that the proposed CPB-CHPD model has much better synergic benefits than the model considering only PDTP or BTI on wind power integration and total operation cost savings.

  1. Thermodynamic analysis of waste heat power generation system

    International Nuclear Information System (INIS)

    Guo, Jiangfeng; Xu, Mingtian; Cheng, Lin

    2010-01-01

    In the present work, a waste heat power generation system is analyzed based on the criteria with and without considering the heat/exergy loss to the environment. For the criteria without considering the heat/exergy loss to the environment, the first- and second-law efficiencies display different tendencies with the variations of some system parameters. When the heat/exergy loss to the environment is taken into consideration, the first and second law efficiencies display the same tendency. Thus, choosing the appropriate expressions for the performance criteria is crucial for the optimization design of the waste heat power generation system. It is found that there are two approaches to improving the system performance: one is to improve the heat/exergy input; the other is to enhance the heat-work conversion ability of the system. The former would deteriorate the environment if the heat-work conversion ability of the system remains unchanged; the latter could reduce the environmental impact but it's restricted by the heat/exergy input. Therefore, the optimal operation condition should be achieved at the trade-off between the heat/exergy input and the heat-work conversion ability of the system.

  2. Micro-Combined Heat and Power Device Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — NIST has developed a test facility for micro-combined heat and power (micro-CHP) devices to measure their performance over a range of different operating strategies...

  3. Coal-Fired Power Plant Heat Rate Reductions

    Science.gov (United States)

    View a report that identifies systems and equipment in coal-fired power plants where efficiency improvements can be realized, and provides estimates of the resulting net plant heat rate reductions and costs for implementation.

  4. Sustainability assessment of renewable power and heat generation technologies

    International Nuclear Information System (INIS)

    Dombi, Mihály; Kuti, István; Balogh, Péter

    2014-01-01

    Rationalisation of consumption, more efficient energy usage and a new energy structure are needed to be achieved in order to shift the structure of energy system towards sustainability. The required energy system is among others characterised by intensive utilisation of renewable energy sources (RES). RES technologies have their own advantages and disadvantages. Nevertheless, for the strategic planning there is a great demand for the comparison of RES technologies. Furthermore, there are additional functions of RES utilisation expected beyond climate change mitigation, e.g. increment of employment, economic growth and rural development. The aim of the study was to reveal the most beneficial RES technologies with special respect to sustainability. Ten technologies of power generation and seven technologies of heat supply were examined in a multi-criteria sustainability assessment frame of seven attributes which were evaluated based on a choice experiment (CE) survey. According to experts the most important characteristics of RES utilisation technologies are land demand and social impacts i.e. increase in employment and local income generation. Concentrated solar power (CSP), hydropower and geothermal power plants are favourable technologies for power generation, while geothermal district heating, pellet-based non-grid heating and solar thermal heating can offer significant advantages in case of heat supply. - highlights: • We used choice experiment to estimate the weights of criteria for the sustainability assessment of RES technologies. • The most important attributes of RES technologies according to experts are land demand and social impacts. • Concentrated solar power (CSP), hydropower and geothermal power plants are advantageous technologies for power generation. • Geothermal district heating, pellet-based non-grid heating and solar thermal heating are favourable in case of heat supply

  5. Plate heat exchangers in the power plant industry

    International Nuclear Information System (INIS)

    Wersel, M.; Ridell, B.

    1984-01-01

    An increase in heat transfer and stability, small investment, high flexibility, easy maintenance and corrosion resistance are obtained by the design and construction of plate heat exchangers and by the introduction of the herringbone pattern. The plate heat exchanger can be used in nearly 90% of all secondary circuits in powerstations. Examples of its installation are the WYLFA, GENTILLY, RINGHALS and TVO Finland nuclear power-stations. (DG) [de

  6. Power generation from low-temperature heat source

    Energy Technology Data Exchange (ETDEWEB)

    Lakew, Amlaku Abie

    2012-07-01

    The potential of low-temperature heat sources for power production has been discussed for decades. The diversity and availability of low-temperature heat sources makes it interesting for power production. The thermodynamic power cycle is one of the promising technologies to produce electricity from low-temperature heat sources. There are different working fluids to be used in a thermodynamic power cycle. Working fluid selection is essential for the performance of the power cycle. Over the last years, different working fluid screening criteria have been used. In broad speaking the screening criteria can be grouped as thermodynamic performance, component size requirement, economic performance, safety and environmental impact. Screening of working fluids at different heat source temperatures (80-200 Celsius degrees) using thermodynamic performance (power output and exergy efficiency) and component size (heat exchanger and turbine) is investigated. It is found that the 'best' working fluid depends on the criteria used and heat source temperature level. Transcritical power cycles using carbon dioxide as a working fluid is studied to produce power at 100 Celsius degrees. Carbon dioxide is an environmentally friendly refrigerant. The global warming potential of carbon dioxide is 1. Furthermore, because of its low critical temperature (31 Celsius degrees), carbon dioxide can operate in a transcritical power cycle for lower heat source temperatures. A transcritical configuration avoids the problem of pinching which otherwise would happened in subcritical power cycle. In the process, better temperature matching is achieved and more heat is extracted. Thermodynamic analysis of transcritical cycle is performed; it is found that there is an optimal operating pressure for highest net power output. The pump work is a sizable fraction of the work produced by the turbine. The effect of efficiency deterioration of the pump and the turbine is compared. When the

  7. Heat Transfer Phenomena in Concentrating Solar Power Systems.

    Energy Technology Data Exchange (ETDEWEB)

    Armijo, Kenneth Miguel; Shinde, Subhash L.

    2016-11-01

    Concentrating solar power (CSP) utilizes solar thermal energy to drive a thermal power cycle for the generation of electricity. CSP systems are facilitated as large, centralized power plants , such as power towers and trough systems, to take advantage of ec onomies of scale through dispatchable thermal energy storage, which is a principle advantage over other energy generation systems . Additionally, the combination of large solar concentration ratios with high solar conversion efficiencies provides a strong o pportunity of employment of specific power cycles such as the Brayton gas cycle that utilizes super critical fluids such as supercritical carbon dioxide (s CO 2 ) , compared to other sola r - fossil hybrid power plants. A comprehensive thermal - fluids examination is provided by this work of various heat transfer phenomena evident in CSP technologies. These include sub - systems and heat transfer fundamental phenomena evident within CSP systems , which include s receivers, heat transfer fluids (HTFs), thermal storage me dia and system designs , thermodynamic power block systems/components, as well as high - temperature materials. This work provides literature reviews, trade studies, and phenomenological comparisons of heat transfer media (HTM) and components and systems, all for promotion of high performance and efficient CSP systems. In addition, f urther investigations are also conducted that provide advanced heat transfer modeling approaches for gas - particle receiver systems , as well as performance/efficiency enhancement re commendations, particularly for solarized supercritical power systems .

  8. Low-temperature nuclear heat applications: Nuclear power plants for district heating

    International Nuclear Information System (INIS)

    1987-08-01

    The IAEA reflected the needs of its Member States for the exchange of information in the field of nuclear heat application already in the late 1970s. In the early 1980s, some Member States showed their interest in the use of heat from electricity producing nuclear power plants and in the development of nuclear heating plants. Accordingly, a technical committee meeting with a workshop was organized in 1983 to review the status of nuclear heat application which confirmed both the progress made in this field and the renewed interest of Member States in an active exchange of information about this subject. In 1985 an Advisory Group summarized the Potential of Low-Temperature Nuclear Heat Application; the relevant Technical Document reviewing the situation in the IAEA's Member States was issued in 1986 (IAEA-TECDOC-397). Programme plans were made for 1986-88 and the IAEA was asked to promote the exchange of information, with specific emphasis on the design criteria, operating experience, safety requirements and specifications for heat-only reactors, co-generation plants and power plants adapted for heat application. Because of a growing interest of the IAEA's Member States about nuclear heat employment in the district heating domaine, an Advisory Group meeting was organized by the IAEA on ''Low-Temperature Nuclear Heat Application: Nuclear Power Plants for District Heating'' in Prague, Czechoslovakia in June 1986. The information gained up to 1986 and discussed during this meeting is embodied in the present Technical Document. 22 figs, 11 tabs

  9. Geothermal energy: the earth, source of heat and electric power

    International Nuclear Information System (INIS)

    Lenoir, D.

    2005-01-01

    This document provides information on the geothermal energy. It presents the different types of geothermal deposits (very low, low and medium energy geothermal energy), the french deposits and the heat production. The electric power production from the geothermal energy is also discussed with the example of Soultz-sous-Forets. The last part deals with the heat pumps. (A.L.B.)

  10. Thermionic Power Cell To Harness Heat Energies for Geothermal Applications

    Science.gov (United States)

    Manohara, Harish; Mojarradi, Mohammad; Greer, Harold F.

    2011-01-01

    A unit thermionic power cell (TPC) concept has been developed that converts natural heat found in high-temperature environments (460 to 700 C) into electrical power for in situ instruments and electronics. Thermionic emission of electrons occurs when an emitter filament is heated to gwhite hot h temperatures (>1,000 C) allowing electrons to overcome the potential barrier and emit into the vacuum. These electrons are then collected by an anode, and transported to the external circuit for energy storage.

  11. Nuclear power plant waste heat utilization

    Energy Technology Data Exchange (ETDEWEB)

    Ryther, J.H.; Huke, R.E.; Archer, J.C.; Price, D.R.; Jewell, W.J.; Hayes, T.D.; Witherby, H.R.

    1977-09-01

    The possibility of using Vermont Yankee condenser effluent for commercial food growth enhancement was examined. It was concluded that for the Vermont Yankee Nuclear Station, commercial success, both for horticulture and aquaculture endeavors, could not be assured without additional research in both areas. This is due primarily to two problems. First, the particularly low heat quality of our condenser discharge, being nominally 72 +- 2/sup 0/F; and second, to the capital intensive support systems. The capital needed for the support systems include costs of pumps, piping and controls to move the heated water to growing facilities and the costs of large, efficient heat exchangers that may be necessary to avoid regulatory difficulties due to the 1958 Delaney Amendment to the U.S. Food, Drug and Cosmetics Act. Recommendations for further work include construction of a permanent aquaculture research laboratory and a test greenhouse complex based on a greenhouse wherein a variety of heating configurations would be installed and tested. One greenhouse would be heated with biogas from an adjacent anaerobic digester thermally boosted during winter months by Vermont Yankee condenser effluent. The aquaculture laboratory would initially be dedicated to the Atlantic salmon restoration program. It appears possible to raise fingerling salmon to smolt size within 7 months using water warmed to about 60/sup 0/F. The growth rate by this technique is increased by a factor of 2 to 3. A system concept has been developed which includes an aqua-laboratory, producing 25,000 salmon smolt annually, a 4-unit greenhouse test horticulture complex and an 18,000 square foot commercial fish-rearing facility producing 100,000 pounds of wet fish (brook trout) per year. The aqualab and horticulture test complex would form the initial phase of construction. The trout-rearing facility would be delayed pending results of laboratory studies confirming its commercial viability.

  12. Nuclear power plant waste heat utilization

    International Nuclear Information System (INIS)

    Ryther, J.H.; Huke, R.E.; Archer, J.C.; Price, D.R.; Jewell, W.J.; Hayes, T.D.; Witherby, H.R.

    1977-09-01

    The possibility of using Vermont Yankee condenser effluent for commercial food growth enhancement was examined. It was concluded that for the Vermont Yankee Nuclear Station, commercial success, both for horticulture and aquaculture endeavors, could not be assured without additional research in both areas. This is due primarily to two problems. First, the particularly low heat quality of our condenser discharge, being nominally 72 +- 2 0 F; and second, to the capital intensive support systems. The capital needed for the support systems include costs of pumps, piping and controls to move the heated water to growing facilities and the costs of large, efficient heat exchangers that may be necessary to avoid regulatory difficulties due to the 1958 Delaney Amendment to the U.S. Food, Drug and Cosmetics Act. Recommendations for further work include construction of a permanent aquaculture research laboratory and a test greenhouse complex based on a greenhouse wherein a variety of heating configurations would be installed and tested. One greenhouse would be heated with biogas from an adjacent anaerobic digester thermally boosted during winter months by Vermont Yankee condenser effluent. The aquaculture laboratory would initially be dedicated to the Atlantic salmon restoration program. It appears possible to raise fingerling salmon to smolt size within 7 months using water warmed to about 60 0 F. The growth rate by this technique is increased by a factor of 2 to 3. A system concept has been developed which includes an aqua-laboratory, producing 25,000 salmon smolt annually, a 4-unit greenhouse test horticulture complex and an 18,000 square foot commercial fish-rearing facility producing 100,000 pounds of wet fish (brook trout) per year. The aqualab and horticulture test complex would form the initial phase of construction. The trout-rearing facility would be delayed pending results of laboratory studies confirming its commercial viability

  13. Influence of wind power, plug-in electric vehicles, and heat storages on power system investments

    DEFF Research Database (Denmark)

    Kiviluoma, Juha; Meibom, Peter

    2010-01-01

    Due to rising fuel costs, the substantial price for CO2 emissions and decreasing wind power costs, wind power might become the least expensive source of power for an increasing number of power systems. This poses the questions of how wind power might change optimal investments in other forms...... of power production and what kind of means could be used to increase power system flexibility in order to incorporate the variable power production from wind power in a cost-effective manner. We have analysed possible effects using an investment model that combines heat and power production and simulates...... electric vehicles. The model runs in an hourly time scale in order to accommodate the impact of variable power production from wind power. Electric vehicles store electricity for later use and can thus serve to increase the flexibility of the power system. Flexibility can also be upgraded by using heat...

  14. CHP in Switzerland from 1990 to 1998. Thermal power generation including combined heat and power

    International Nuclear Information System (INIS)

    Kaufmann, U.

    1999-01-01

    The results of a study on thermal power generation in Switzerland show that combined heat and power (CHP) systems have grown rapidly. Statistics are presented on the development of CHP-based power and also on thermal power stations without waste heat usage. Figures are given for gas and steam turbine installations, combined gas and steam turbine stations and motor-driven CHP units. Power production is categorised, separating small and large (over 1 Megawatt electrical) power generation facilities. On-site, distributed power generation at consumers' premises and the geographical distribution of plant is described

  15. Combined Heat and Power (CHP) Partnership

    Science.gov (United States)

    The CHP Partnership seeks to reduce air pollution and water usage associated with electric power generation by promoting the use of CHP. The Partnership works to remove policy barriers and to facilitate the development of new projects.

  16. Using Heat Pump Energy Storages in the Power Grid

    DEFF Research Database (Denmark)

    Pedersen, Tom S.; Andersen, Palle; Nielsen, Kirsten M.

    2011-01-01

    The extensive growth of installed wind energy plants lead to increasing balancing problems in the power grid due to the nature of wind fields and diurnal variations in consumption. One way to overcome these problems is to move consumption to times where wind power otherwise cause overproduction...... and large fluctuations in prices. The paper presents a method which takes advantage of heat capacity in single-family houses using heat pumps which are anticipated to be installed in large numbers in Denmark in next decade. This type of heating gives a large time constant and it is shown possible to move...

  17. The capacity credit of micro-combined heat and power

    International Nuclear Information System (INIS)

    Hawkes, A.D.; Leach, M.A.

    2008-01-01

    This article is concerned with development of a methodology to determine the capacity credit of micro-combined heat and power (micro-CHP), and application of the method for the UK. Capacity credit is an important parameter in electricity system planning because it measures the amount of conventional generation that would be displaced by an alternative technology. Firstly, a mathematical formulation is presented. Capacity credit is then calculated for three types of micro-CHP units-Stirling engine, internal combustion engine, and fuel cell systems-operating under various control strategies. It is found that low heat-to-power ratio fuel cell technologies achieve the highest capacity credit of approximately 85% for a 1.1 GW penetration when a heat-led control strategy is applied. Higher heat-to-power ratio Stirling engine technology achieves approximately 33% capacity credit for heat-led operation. Low heat-to-power ratio technologies achieve higher capacity credit because they are able to continue operating even when heat demand is relatively low. Capacity credit diminishes as penetration of the technology increases. Overall, the high capacity credit of micro-CHP contributes to the viewpoint that the technology can help meet a number of economic and environmental energy policy aims

  18. Exploration of high harmonic fast wave heating on the National Spherical Torus Experiment

    International Nuclear Information System (INIS)

    Wilson, J.R.; Bell, R.E.; Bernabei, S.; Bitter, M.; Gates, D.; Hosea, J.; Le Blanc, B.; Medley, S.; Menard, J.; Mueller, D.; Ono, M.; Phillips, C.K.; Rosenberg, A.; Bonoli, P.; Mau, T.K.; Pinsker, R.I.; Raman, R.; Ryan, P.; Swain, D.; Wilgen, J.

    2003-01-01

    High harmonic fast wave (HHFW) heating has been proposed as a particularly attractive means for plasma heating and current drive in the high beta plasmas that are achievable in spherical torus (ST) devices. The National Spherical Torus Experiment (NSTX) [M. Ono, S. M. Kaye, S. Neumeyer et al., in Proceedings of the 18th IEEE/NPSS Symposium on Fusion Engineering, Albuquerque, 1999 (IEEE, Piscataway, NJ, 1999), p. 53] is such a device. An rf heating system has been installed on the NSTX to explore the physics of HHFW heating, current drive via rf waves and for use as a tool to demonstrate the attractiveness of the ST concept as a fusion device. To date, experiments have demonstrated many of the theoretical predictions for HHFW. In particular, strong wave absorption on electrons over a wide range of plasma parameters and wave parallel phase velocities, wave acceleration of energetic ions, and indications of current drive for directed wave spectra have been observed. In addition HHFW heating has been used to explore the energy transport properties of NSTX plasmas, to create H-mode discharges with a large fraction of bootstrap current and to control the plasma current profile during the early stages of the discharge

  19. Exploration of High Harmonic Fast Wave Heating on the National Spherical Torus Experiment

    International Nuclear Information System (INIS)

    Wilson, J.R.; Bell, R.E.; Bernabei, S.; Bitter, M.; Bonoli, P.; Gates, D.; Hosea, J.; LeBlanc, B.; Mau, T.K.; Medley, S.; Menard, J.; Mueller, D.; Ono, M.; Phillips, C.K.; Pinsker, R.I.; Raman, R.; Rosenberg, A.; Ryan, P.; Sabbagh, S.; Stutman, D.; Swain, D.; Takase, Y.; Wilgen, J.

    2003-01-01

    High Harmonic Fast Wave (HHFW) heating has been proposed as a particularly attractive means for plasma heating and current drive in the high-beta plasmas that are achievable in spherical torus (ST) devices. The National Spherical Torus Experiment (NSTX) [Ono, M., Kaye, S.M., Neumeyer, S., et al., Proceedings, 18th IEEE/NPSS Symposium on Fusion Engineering, Albuquerque, 1999, (IEEE, Piscataway, NJ (1999), p. 53.)] is such a device. An radio-frequency (rf) heating system has been installed on NSTX to explore the physics of HHFW heating, current drive via rf waves and for use as a tool to demonstrate the attractiveness of the ST concept as a fusion device. To date, experiments have demonstrated many of the theoretical predictions for HHFW. In particular, strong wave absorption on electrons over a wide range of plasma parameters and wave parallel phase velocities, wave acceleration of energetic ions, and indications of current drive for directed wave spectra have been observed. In addition HHFW heating has been used to explore the energy transport properties of NSTX plasmas, to create H-mode (high-confinement mode) discharges with a large fraction of bootstrap current and to control the plasma current profile during the early stages of the discharge

  20. Solar Powered Heat Storage for Injera Baking

    OpenAIRE

    Tesfay, Asfafaw H; Kahsay, Mulu Bayray; Nydal, Ole Jørgen

    2014-01-01

    Ethiopia with a population of about 85 million meets 96% of its energy needs with bio-mass, charcoal, wood, animal dung and plant residues. More than 50% of this energy goes entirely on baking Injera. Injera the national food of the country demands 180-220 °C to be well cooked. In this article; Injera baking with solar energy on off-focus system, status of electric powered stove and the potential for solar powered stoves is discussed. The research and development of solar thermal for househol...

  1. Environmental radioactivity at the heat power complex enterprises

    International Nuclear Information System (INIS)

    Krylov, D.A.; Putintseva, V.E.

    1997-01-01

    Environmental radioactivity at the heat power complex enterprises (coal mines, oil and gas deposits, coal thermal power plants and heat-electric generation plant) is considered. IT is shown that elevated level of radiation effect on the personnel lungs (2-3 times higher than that of safety standard) is observed at 80 coal mines. High levels of gamma radiation from natural radionuclides (300 μR/h and above) are marked at the separate objects of oil and gas mining industry. It is revealed that the contamination of ash wastes resulted from certain coals combustion reaches 520 Bq/kg at separate thermal power plants

  2. Combined heat and power economic dispatch by harmony search algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Vasebi, A.; Bathaee, S.M.T. [Power System Research Laboratory, Department of Electrical and Electronic Engineering, K.N.Toosi University of Technology, 322-Mirdamad Avenue West, 19697 Tehran (Iran); Fesanghary, M. [Department of Mechanical Engineering, Amirkabir University of Technology, 424-Hafez Avenue, Tehran (Iran)

    2007-12-15

    The optimal utilization of multiple combined heat and power (CHP) systems is a complicated problem that needs powerful methods to solve. This paper presents a harmony search (HS) algorithm to solve the combined heat and power economic dispatch (CHPED) problem. The HS algorithm is a recently developed meta-heuristic algorithm, and has been very successful in a wide variety of optimization problems. The method is illustrated using a test case taken from the literature as well as a new one proposed by authors. Numerical results reveal that the proposed algorithm can find better solutions when compared to conventional methods and is an efficient search algorithm for CHPED problem. (author)

  3. Heat engine development for solar thermal power systems

    Science.gov (United States)

    Pham, H. Q.; Jaffe, L. D.

    The parabolic dish solar collector systems for converting sunlight to electrical power through a heat engine will, require a small heat engine of high performance long lifetime to be competitive with conventional power systems. The most promising engine candidates are Stirling, high temperature Brayton, and combined cycle. Engines available in the current market today do not meet these requirements. The development of Stirling and high temperature Brayton for automotive applications was studied which utilizes much of the technology developed in this automotive program for solar power engines. The technical status of the engine candidates is reviewed and the components that may additional development to meet solar thermal system requirements are identified.

  4. Quantum optomechanical piston engines powered by heat

    Science.gov (United States)

    Mari, A.; Farace, A.; Giovannetti, V.

    2015-09-01

    We study two different models of optomechanical systems where a temperature gradient between two radiation baths is exploited for inducing self-sustained coherent oscillations of a mechanical resonator. From a thermodynamic perspective, such systems represent quantum instances of self-contained thermal machines converting heat into a periodic mechanical motion and thus they can be interpreted as nano-scale analogues of macroscopic piston engines. Our models are potentially suitable for testing fundamental aspects of quantum thermodynamics in the laboratory and for applications in energy efficient nanotechnology.

  5. Quantum optomechanical piston engines powered by heat

    International Nuclear Information System (INIS)

    Mari, A; Farace, A; Giovannetti, V

    2015-01-01

    We study two different models of optomechanical systems where a temperature gradient between two radiation baths is exploited for inducing self-sustained coherent oscillations of a mechanical resonator. From a thermodynamic perspective, such systems represent quantum instances of self-contained thermal machines converting heat into a periodic mechanical motion and thus they can be interpreted as nano-scale analogues of macroscopic piston engines. Our models are potentially suitable for testing fundamental aspects of quantum thermodynamics in the laboratory and for applications in energy efficient nanotechnology. (paper)

  6. Optimization of Temperature Schedule Parameters on Heat Supply in Power-and-Heat Supply Systems

    Directory of Open Access Journals (Sweden)

    V. A. Sednin

    2009-01-01

    Full Text Available The paper considers problems concerning optimization of a temperature schedule in the district heating systems with steam-turbine thermal power stations having average initial steam parameters. It has been shown in the paper that upkeeping of an optimum network water temperature permits to increase an energy efficiency of heat supply due to additional systematic saving of fuel. 

  7. Simultaneous power generation and heat recovery using a heat pipe assisted thermoelectric generator system

    International Nuclear Information System (INIS)

    Remeli, Muhammad Fairuz; Tan, Lippong; Date, Abhijit; Singh, Baljit; Akbarzadeh, Aliakbar

    2015-01-01

    Highlights: • A new passive power cogeneration system using industrial waste heat was introduced. • Heat pipes and thermoelectrics were used for recovering waste heat and electricity. • Theoretical model predicted the 2 kW test rig could recover 1.345 kW thermal power. • 10.39 W electrical power was produced equivalent to 0.77% conversion efficiency. - Abstract: This research explores a new method of recovering waste heat and electricity using a combination of heat pipes and thermoelectric generators (HP-TEG). The HP-TEG system consists of Bismuth Telluride (Bi 2 Te 3 ) based thermoelectric generators (TEGs), which are sandwiched between two finned heat pipes to achieve a temperature gradient across the TEG for thermoelectricity generation. A theoretical model was developed to predict the waste heat recovery and electricity conversion performances of the HP-TEG system under different parametric conditions. The modelling results show that the HP-TEG system has the capability of recovering 1.345 kW of waste heat and generating 10.39 W of electrical power using 8 installed TEGs. An experimental test bench for the HP-TEG system is under development and will be discussed in this paper

  8. Reverse electrodialysis heat engine for sustainable power production

    International Nuclear Information System (INIS)

    Tamburini, A.; Tedesco, M.; Cipollina, A.; Micale, G.; Ciofalo, M.; Papapetrou, M.; Van Baak, W.; Piacentino, A.

    2017-01-01

    Graphical abstract: State of the art technologies for the conversion of heat into power. Grey circles refer to technologies at very early stage of development and non-available at industrial level. The Carnot efficiency (on the secondary horizontal axis) is evaluated assuming a cold sink temperature of 25 °C. SRC-hot gases: Steam Rankine Cycle integrated with gas turbine/other topping cycles; SRC-fuel: Steam Rankine Cycle directly fuelled by oil, coal or other fuels; KC: Kalina Cycle; ORC: Organic Rankine Cycle; TEG: Thermoelectric Generation; PEPG: Piezoelectric Power Generation with waste heat-powered expansion/compression cycle; OHE: Osmotic Heat Engine; REDHE, Reverse Electrodialysis Heat Engine (this paper). Display Omitted -- Highlights: •For the first time, the potential of Reverse Electrodialysis Heat Engine is assessed. •An overview of the possible regeneration methods is presented. •Performance of the RED unit fed by different salty solutions was suitably optimized. •Three different RED Heat Engine scenarios were studied. •Exergetic efficiency of about 85% could be achieved in the foreseen future. -- Abstract: Reverse Electrodialysis Heat Engine (REDHE) is a promising technology to convert waste heat at temperatures lower than 100 °C into electric power. In the present work an overview of the possible regeneration methods is presented and the technological challenges for the development of the RED Heat Engine (REDHE) are identified. The potential of this power production cycle was investigated through a simplified mathematical model. In the first part of the work, several salts were singularly modelled as possible solutes in aqueous solutions feeding the RED unit and the corresponding optimal conditions were recognized via an optimization study. In the second part, three different RED Heat Engine scenarios were studied. Results show that power densities much higher than those relevant to NaCl-water solutions can be obtained by using different

  9. Heat Pipe-Assisted Thermoelectric Power Generation Technology for Waste Heat Recovery

    Science.gov (United States)

    Jang, Ju-Chan; Chi, Ri-Guang; Rhi, Seok-Ho; Lee, Kye-Bock; Hwang, Hyun-Chang; Lee, Ji-Su; Lee, Wook-Hyun

    2015-06-01

    Currently, large amounts of thermal energy dissipated from automobiles are emitted through hot exhaust pipes. This has resulted in the need for a new efficient recycling method to recover energy from waste hot exhaust gas. The present experimental study investigated how to improve the power output of a thermoelectric generator (TEG) system assisted by a wickless loop heat pipe (loop thermosyphon) under the limited space of the exhaust gas pipeline. The present study shows a novel loop-type heat pipe-assisted TEG concept to be applied to hybrid vehicles. The operating temperature of a TEG's hot side surface should be as high as possible to maximize the Seebeck effect. The present study shows a novel TEG concept of transferring heat from the source to the sink. This technology can transfer waste heat to any local place with a loop-type heat pipe. The present TEG system with a heat pipe can transfer heat and generate an electromotive force power of around 1.3 V in the case of 170°C hot exhaust gas. Two thermoelectric modules (TEMs) for a conductive block model and four Bi2Te3 TEMs with a heat pipe-assisted model were installed in the condenser section. Heat flows to the condenser section from the evaporator section connected to the exhaust pipe. This novel TEG system with a heat pipe can be placed in any location on an automobile.

  10. Economical photovoltaic power generation with heat recovery

    Science.gov (United States)

    Ascher, G.

    1977-01-01

    Three designs for conversion of solar radiation to electricity and thermal energy are analyzed. The objective of these converters is to increase the electric and thermal output for each photovoltaic array so as to lower the cell cost relative to the amount of energy delivered. An analysis of the economical aspects of conversion by photovoltaic cells with heat recovery is carried out in terms of hypothetical examples. Thus, it is shown that the original cost of say $40,000 per generated kilowat can be reduced to $572.00 per kilowatt by increasing the original electric output of 1 kW to 10 kW in electricity and 60 kW in thermal energy. The newly derived specific cost is only 1.4 percent of the original one. It is expected that a cost reduction of roughly 2% of the present specific cost per kilowatt will greatly stimulate public acceptance of photovoltaic terrestrial conversion to electricity.

  11. Active Power Flow Optimization of Industrial Power Supply with Regard to the Transmission Line Conductor Heating

    Directory of Open Access Journals (Sweden)

    Leyzgold D.Yu.

    2015-04-01

    Full Text Available This article studies the problem of the transmission line conductor heating effect on the active power flows optimization in the local segment of industrial power supply. The purpose is to determine the optimal generation rating of the distributed power sources, in which the power flow values will correspond to the minimum active power losses in the power supply. The timeliness is the need to define the most appropriate rated power values of distributed sources which will be connected to current industrial power supply. Basing on the model of active power flow optimization, authors formulate the description of the nonlinear transportation problem considering the active power losses depending on the transmission line conductor heating. Authors proposed a new approach to the heating model parameters definition based on allowable current loads and nominal parameters of conductors as part of the optimization problem. Analysis of study results showed that, despite the relatively small active power losses reduction to the tune 0,45% due to accounting of the conductors heating effect for the present configuration of power supply, there are significant fluctuations in the required generation rating in nodes of the network to 9,32% within seasonal changes in the outer air temperature. This fact should be taken into account when selecting the optimum power of distributed generation systems, as exemplified by an arbitrary network configuration.

  12. Transient heat pipe investigations for space power systems

    International Nuclear Information System (INIS)

    Merrigan, M.A.; Keddy, E.S.; Sena, J.T.

    1985-01-01

    A 4-meter long, high temperature, high power, molybdenum-lithium heat pipe has been fabricated and tested in transient and steady state operation at temperatures to 1500 K. Maximum power throughput during the tests was approximately 37 kW/cm 2 for the 1.4 cm diameter vapor space of the annular wick heat pipe. The evaporator flux density for the tests was 150.0 W/cm 2 over a length of 40 cm. Condenser length was approximately 3.0 m with radiant heat rejection from the condenser to a coaxial, water cooled radiation calorimeter. A variable radiation shield, controllable from the outside of the vacuum enclosure, was used to vary the load on the heat pipe during the tests. 1 ref., 9 figs

  13. High efficiency heat transport and power conversion system for cascade

    International Nuclear Information System (INIS)

    Maya, I.; Bourque, R.F.; Creedon, R.L.; Schultz, K.R.

    1985-02-01

    The Cascade ICF reactor features a flowing blanket of solid BeO and LiAlO 2 granules with very high temperature capability (up to approx. 2300 K). The authors present here the design of a high temperature granule transport and heat exchange system, and two options for high efficiency power conversion. The centrifugal-throw transport system uses the peripheral speed imparted to the granules by the rotating chamber to effect granule transport and requires no additional equipment. The heat exchanger design is a vacuum heat transfer concept utilizing gravity-induced flow of the granules over ceramic heat exchange surfaces. A reference Brayton power cycle is presented which achieves 55% net efficiency with 1300 K peak helium temperature. A modified Field steam cycle (a hybrid Rankine/Brayton cycle) is presented as an alternate which achieves 56% net efficiency

  14. After-heat removing device in nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Mizuno, K [Nippon Atomic Industry Group Co. Ltd., Tokyo

    1977-01-14

    Purpose: To prevent water hammer in a BWR type reactor or the like by moving water in pipe lines having stagnant portions in an after-heat removing device. Constitution: To a reactor container, is provided a recycling pump which constitutes a closed loop type recycling system in a nuclear power plant together with a pressure vessel and pipe lines. A pump and a heat exchanger are provided outside of the reactor container and they are connected to up- and down-streams of the recycling pump to form an after-heat removing device in the plant. Upon shutdown of the nuclear power plant, since water in the stagnant portion flows to the intake port of the recycling pump and water from the reactor is spontaneously supplemented thereafter to the stagnant portion, neither pressurized water nor heated steam is generated and thus water hammer is prevented.

  15. Use of waste heat from nuclear power plants

    International Nuclear Information System (INIS)

    Olszewski, M.

    1978-01-01

    The paper details the Department of Energy (DOE) program concerning utilization of power plant reject heat conducted by the Oak Ridge National Laboratory (ORNL). A brief description of the historical development of the program is given and results of recent studies are outlined to indicate the scope of present efforts. A description of a DOE-sponsored project assessing uses for reject heat from the Vermont Yankee Nuclear Station is also given

  16. Solubilization of bovine gelatin using power ultrasound: gelation without heating.

    Science.gov (United States)

    Farahnaky, Asgar; Zendeboodi, Fatemeh; Azizi, Rezvan; Mesbahi, Gholamreza; Majzoobi, Mahsa

    2017-04-01

    The aim of this study was to investigate the efficacy of power ultrasound without using any heating stage in solubilizeing gelatin dispersions, and to characterize the mechanical and microstructural properties of the resulting gels using texture analysis and scanning electron microscopy, respectively. Usually to prepare a gel from gelatin, a primary heating stage of at about 40C or above is required to solubilize gelatin macromolecules. In this study solubilizing gelatin dispersions using power ultrasound without any heating was successfully performed. For solubilising gelatin, an ultrasound equipment with a frequency of 20 kHz, amplitude of 100% and power range of 50-150 W was used. Aqueous gelatin dispersions (4% w/v) were subjected to ultrasound for different times (40-240 s) at a constant temperature of 13C. Applying ultrasound to gelatin dispersions caused increases in water absorption and water solubility of the hydrocolloid. The textural parameters of the resulting gelatin gels, increased with increasing time and power of ultrasound. Moreover, a generalized Maxwell model with three elements was used for calculating relaxation times of the gels. The microstructural observations by SEM showed that the structural cohesiveness of the gels increased by increasing ultrasonication time. Ultrasound-assisted solubilization of gelatin can have emerging implications for industrial uses in pharmaceuticals, food and non-food systems. Usually to prepare a gel from gelatin, a primary heating stage of at about 40C or above is required to solubilize gelatin macromolecules. Therefore, the use of gelatin as a hydrocolloid in food processings or pharmaceutical formulations which lack a heating step has been a technological and practical challenge. In this study solubilizing gelatin dispersions using power ultrasound without any heating was successfully performed. Ultrasound-assisted solubilisation of gelatin can have emerging implications for industrial uses in pharmaceuticals

  17. Problems of power-heat-coupling in industry

    Energy Technology Data Exchange (ETDEWEB)

    1977-03-01

    The coupled heat and electric power supply from counter-pressure and partly also from extraction-condensing plants theoretically offers the best possibilities for saving energy in comparison to other measures which reduce the primary energy employed at equal useful energy. A basic requirement for the use of this principle of power-heat coupling is a somewhat simultaneous need of heat and electrical energy as well as a relatively short distance between production point and consumption point, since the transfer ability of the heat is limited due to the considerable cost of the transportation system. Numerous industrial enterprises offer favorable conditions for the use of power-heat coupling. Because of the existing legal and contract rights restraints, the incentive for a free development of industrial power-heat coupling with the aim of saving energy is strongly weakened. Therefore a new order to road rights is nececessary, which would make possible the construction and operation of common plants for several industrial operations and which would insure the right to lay industrial energy lines in public roads where reasonably possible. It has been proven necessary to make it the duty of the cartel authorities to orient their examinations of price regulations for auxiliary and reserve electric power supply solely on the objective electricity economy facts, but not on so-called advantageous points of view. Ultimately the regulation for common use of the utilities own piping system for the purpose of saving and piping free energy and free power from its own plants can be reasonably necessary in the utilities realm, if free agreements between the utility and the industry are not enough in this question.

  18. Frictional Heating with Time-Dependent Specific Power of Friction

    Directory of Open Access Journals (Sweden)

    Topczewska Katarzyna

    2017-06-01

    Full Text Available In this paper analytical solutions of the thermal problems of friction were received. The appropriate boundary-value problems of heat conduction were formulated and solved for a homogeneous semi–space (a brake disc heated on its free surface by frictional heat fluxes with different and time-dependent intensities. Solutions were obtained in dimensionless form using Duhamel's theorem. Based on received solutions, evolution and spatial distribution of the dimensionless temperature were analyzed using numerical methods. The numerical results allowed to determine influence of the time distribution of friction power on the spatio-temporal temperature distribution in brake disc.

  19. Novel Power Electronics Three-Dimensional Heat Exchanger: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Bennion, K.; Cousineau, J.; Lustbader, J.; Narumanchi, S.

    2014-08-01

    Electric drive systems for vehicle propulsion enable technologies critical to meeting challenges for energy, environmental, and economic security. Enabling cost-effective electric drive systems requires reductions in inverter power semiconductor area. As critical components of the electric drive system are made smaller, heat removal becomes an increasing challenge. In this paper, we demonstrate an integrated approach to the design of thermal management systems for power semiconductors that matches the passive thermal resistance of the packaging with the active convective cooling performance of the heat exchanger. The heat exchanger concept builds on existing semiconductor thermal management improvements described in literature and patents, which include improved bonded interface materials, direct cooling of the semiconductor packages, and double-sided cooling. The key difference in the described concept is the achievement of high heat transfer performance with less aggressive cooling techniques by optimizing the passive and active heat transfer paths. An extruded aluminum design was selected because of its lower tooling cost, higher performance, and scalability in comparison to cast aluminum. Results demonstrated a heat flux improvement of a factor of two, and a package heat density improvement over 30%, which achieved the thermal performance targets.

  20. Heat receivers for solar dynamic space power systems

    Science.gov (United States)

    Perez-Davis, Marla Esther

    A review of state-of-the-art technology is presented and discussed for phase change materials. Some of the advanced solar dynamic designs developed as part of the Advanced Heat Receiver Conceptual Design Study performed for LeRC are discussed. The heat receivers are analyzed and several recommendations are proposed, including two new concepts. The first concept evaluated the effect of tube geometries inside the heat receiver. It was found that a triangular configuration would provide better heat transfer to the working fluid, although not necessarily with a reduction in receiver size. A sensible heat receiver considered in this study uses vapor grown graphite fiber-carbon (VGCF/C) composite as the thermal storage media and was designed for a 7 kW Brayton engine. The proposed heat receiver stores the required energy to power the system during eclipse in the VGCF/C composite. The heat receiver analysis was conducted through the Systems Improved Numerical Differencing Analyzer and Fluid Integrator (SINDA) software package. The proposed heat receiver compares well with other latent and advanced sensible heat receivers while avoiding the problems associated with latent heat storage salts and liquid metal heat pipes. The weight and size of the system can be optimized by changes in geometry and technology advances for this new material. In addition to the new concepts, the effect of atomic oxygen on several materials is reviewed. A test was conducted for atomic oxygen attack on boron nitride, which experienced a negligible mass loss when exposed to an atomic oxygen fluence of 5 x 10 exp 21 atoms/sq cm. This material could be used to substitute the graphite aperture plate of the heat receiver.

  1. Selection of criterions of fuels incineration on heat power plants

    International Nuclear Information System (INIS)

    Bubnov, V.P.; Minchenko, E.M.; Zelenukho, E.V.

    2006-01-01

    Fuel and energy complex takes first place in industry field of cities and defines in many respects environmental situation of cities. The products of combustion of fuel bring the greatest contribution in environmental contamination. This factor is ignored during calculation of technical and economics indexes. Ecological impact of heat power plants on the environment is determined separately from assessment of ecological damage. Determination of optimal conditions of functioning of heat power plants incineration with respect to technical, economics and ecological indexes with use of multicriterion mathematics model is proposed. (authors)

  2. Size dependence of efficiency at maximum power of heat engine

    KAUST Repository

    Izumida, Y.; Ito, N.

    2013-01-01

    We perform a molecular dynamics computer simulation of a heat engine model to study how the engine size difference affects its performance. Upon tactically increasing the size of the model anisotropically, we determine that there exists an optimum size at which the model attains the maximum power for the shortest working period. This optimum size locates between the ballistic heat transport region and the diffusive heat transport one. We also study the size dependence of the efficiency at the maximum power. Interestingly, we find that the efficiency at the maximum power around the optimum size attains a value that has been proposed as a universal upper bound, and it even begins to exceed the bound as the size further increases. We explain this behavior of the efficiency at maximum power by using a linear response theory for the heat engine operating under a finite working period, which naturally extends the low-dissipation Carnot cycle model [M. Esposito, R. Kawai, K. Lindenberg, C. Van den Broeck, Phys. Rev. Lett. 105, 150603 (2010)]. The theory also shows that the efficiency at the maximum power under an extreme condition may reach the Carnot efficiency in principle.© EDP Sciences Società Italiana di Fisica Springer-Verlag 2013.

  3. Size dependence of efficiency at maximum power of heat engine

    KAUST Repository

    Izumida, Y.

    2013-10-01

    We perform a molecular dynamics computer simulation of a heat engine model to study how the engine size difference affects its performance. Upon tactically increasing the size of the model anisotropically, we determine that there exists an optimum size at which the model attains the maximum power for the shortest working period. This optimum size locates between the ballistic heat transport region and the diffusive heat transport one. We also study the size dependence of the efficiency at the maximum power. Interestingly, we find that the efficiency at the maximum power around the optimum size attains a value that has been proposed as a universal upper bound, and it even begins to exceed the bound as the size further increases. We explain this behavior of the efficiency at maximum power by using a linear response theory for the heat engine operating under a finite working period, which naturally extends the low-dissipation Carnot cycle model [M. Esposito, R. Kawai, K. Lindenberg, C. Van den Broeck, Phys. Rev. Lett. 105, 150603 (2010)]. The theory also shows that the efficiency at the maximum power under an extreme condition may reach the Carnot efficiency in principle.© EDP Sciences Società Italiana di Fisica Springer-Verlag 2013.

  4. Design of megawatt power level heat pipe reactors

    Energy Technology Data Exchange (ETDEWEB)

    Mcclure, Patrick Ray [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Poston, David Irvin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dasari, Venkateswara Rao [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reid, Robert Stowers [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-12

    An important niche for nuclear energy is the need for power at remote locations removed from a reliable electrical grid. Nuclear energy has potential applications at strategic defense locations, theaters of battle, remote communities, and emergency locations. With proper safeguards, a 1 to 10-MWe (megawatt electric) mobile reactor system could provide robust, self-contained, and long-term power in any environment. Heat pipe-cooled fast-spectrum nuclear reactors have been identified as a candidate for these applications. Heat pipe reactors, using alkali metal heat pipes, are perfectly suited for mobile applications because their nature is inherently simpler, smaller, and more reliable than “traditional” reactors. The goal of this project was to develop a scalable conceptual design for a compact reactor and to identify scaling issues for compact heat pipe cooled reactors in general. Toward this goal two detailed concepts were developed, the first concept with more conventional materials and a power of about 2 MWe and a the second concept with less conventional materials and a power level of about 5 MWe. A series of more qualitative advanced designs were developed (with less detail) that show power levels can be pushed to approximately 30 MWe.

  5. Wind power integration with heat pumps, heat storages, and electric vehicles - Energy systems analysis and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Hedegaard, K.

    2013-09-15

    This PhD investigates to which extent heat pumps, heat storages, and electric vehicles can support the integration of wind power. Considering the gaps in existing research, the main focus is put on individual heat pumps in the residential sector (one-family houses) and the possibilities for flexible operation, using the heat storage options available. Several energy systems analyses are performed using the energy system models, Balmorel, developed at the former TSO, ElkraftSystem, and, EnergyPLAN, developed at Aalborg University. The Danish energy system towards 2030, with wind power penetrations of up to 60 %, is used as a case study in most of the analyses. Both models have been developed further, resulting in an improved representation of individual heat pumps and heat storages. An extensive model add-on for Balmorel renders it possible to optimise investment and operation of individual heat pumps and different types of heat storages, in integration with the energy system. Total costs of the energy system are minimised in the optimisation. The add-on incorporates thermal building dynamics and covers various different heat storage options: intelligent heat storage in the building structure for houses with radiator heating and floor heating, respectively, heat accumulation tanks on the space heating circuit, as well as hot water tanks. In EnergyPLAN, some of the heat storage options have been modelled in a technical optimisation that minimises fuel consumption of the energy system and utilises as much wind power as possible. The energy systems analyses reveal that in terms of supporting wind power integration, the installation of individual heat pumps is an important step, while adding heat storages to the heat pumps is less influential. When equipping the heat pumps with heat storages, only moderate system benefits can be gained. Hereof, the main system benefit is that the need for peak/reserve capacity investments can be reduced through peak load shaving; in

  6. Maximum-power-point tracking control of solar heating system

    KAUST Repository

    Huang, Bin-Juine

    2012-11-01

    The present study developed a maximum-power point tracking control (MPPT) technology for solar heating system to minimize the pumping power consumption at an optimal heat collection. The net solar energy gain Q net (=Q s-W p/η e) was experimentally found to be the cost function for MPPT with maximum point. The feedback tracking control system was developed to track the optimal Q net (denoted Q max). A tracking filter which was derived from the thermal analytical model of the solar heating system was used to determine the instantaneous tracking target Q max(t). The system transfer-function model of solar heating system was also derived experimentally using a step response test and used in the design of tracking feedback control system. The PI controller was designed for a tracking target Q max(t) with a quadratic time function. The MPPT control system was implemented using a microprocessor-based controller and the test results show good tracking performance with small tracking errors. It is seen that the average mass flow rate for the specific test periods in five different days is between 18.1 and 22.9kg/min with average pumping power between 77 and 140W, which is greatly reduced as compared to the standard flow rate at 31kg/min and pumping power 450W which is based on the flow rate 0.02kg/sm 2 defined in the ANSI/ASHRAE 93-1986 Standard and the total collector area 25.9m 2. The average net solar heat collected Q net is between 8.62 and 14.1kW depending on weather condition. The MPPT control of solar heating system has been verified to be able to minimize the pumping energy consumption with optimal solar heat collection. © 2012 Elsevier Ltd.

  7. The competitiveness of biofuels in heat and power production

    International Nuclear Information System (INIS)

    Kosunen, P.; Leino, P.

    1995-01-01

    The paper showed that natural gas is the most competitive fuel in all the energy production alternatives under review, ie both in separate heat production and electricity generation and in combined heat and power production. Even though the heavy fuel oil taxes have grown more rapidly than taxes on domestic fuels, oil continues to be cheaper than solid fuels in heating and steam plants. According to the feasibility calculations made, combined heat and power production is the least-cost production form of electricity, and the larger the plant unit, the lower the cost. Looking to the future, in respect of merely the development in fuel taxes the competitiveness of domestic fuels will improve markedly if the taxation structure remains unchanged. It seems that at smaller points of consumption, such as heating and steam plants and small-scale power plants, fuel chips would be the most competitive fuel. In larger units, such as heat and power production plants and condensing power plants, fuel peat, primarily milled peat, would be the most competitive. The competitiveness of fuel chips at larger plants will probably be limited by the supply of sufficient volumes from such an area where the delivery costs would not raise the price of fuel chips too high. Coal would remain competitive only if the real import price of coal rose clearly more slowly than the real prices of domestic fuels. It seems that heavy fuel oil will be used only as a start-up, support and back-up fuel. Evaluating the future competitiveness of natural gas is difficult, since the impact of new pipeline investments on the price of natural gas is not known

  8. Combined Heat and Power in an open market

    International Nuclear Information System (INIS)

    Hawkins, A.

    1999-01-01

    The chances and risks for combined heat and power (CHP) installations presented by the future liberalisation of the electricity market in Switzerland are discussed. A summary of papers and speeches presented at a conference in Basle is presented. New developments in the electricity marketplace are looked at from the point of view of CHP unit manufacturers, the Federal Administration, energy policy makers and marketing experts. Examples are quoted concerning the situation in Germany and possible changes in power generation philosophy

  9. Calculation of Efficiencies of a Ship Power Plant Operating with Waste Heat Recovery through Combined Heat and Power Production

    Directory of Open Access Journals (Sweden)

    Mirko Grljušić

    2015-05-01

    Full Text Available The aim of this research was to investigate the possibility of a combined heat & power (CHP plant, using the waste heat from a Suezmax-size oil tanker’s main engine, to meet all heating and electricity requirements during navigation. After considering various configurations, a standard propulsion engine operating at maximum efficiency, combined with a supercritical Organic Rankine cycle (ORC system, was selected to supply the auxiliary power, using R245fa or R123 as the working fluid. The system analysis showed that such a plant can meet all heat and electrical power requirements at full load, with the need to burn only a small amount of supplementary fuel in a heat recovery steam generator (HRSG when the main engine operates at part load. Therefore, it is possible to increase the overall thermal efficiency of the ship’s power plant by more than 5% when the main engine operates at 65% or more of its specified maximum continuous rating (SMCR.

  10. Combined heat and power considered as a virtual steam cycle heat pump

    International Nuclear Information System (INIS)

    Lowe, Robert

    2011-01-01

    The first aim of this paper is to shed light on the thermodynamic reasons for the practical pursuit of low temperature operation by engineers involved in the design and the operation of combined heat and power (CHP) and district heating (DH) systems. The paper shows that the steam cycle of a combined heat and power generator is thermodynamically equivalent to a conventional steam cycle generator plus an additional virtual steam cycle heat pump. This apparently novel conceptualisation leads directly to (i) the observed sensitivity of coefficient of performance of CHP to supply and return temperatures in associated DH systems, and (ii) the conclusion that the performance of CHP will tend to be significantly higher than real heat pumps operating at similar temperatures. The second aim, which is pursued more qualitatively, is to show that the thermodynamic performance advantages of CHP are consistent with the goal of deep, long-term decarbonisation of industrialised economies. As an example, estimates are presented, which suggest that CHP based on combined-cycle gas turbines with carbon capture and storage has the potential to reduce the carbon intensity of delivered heat by a factor of ∼30, compared with a base case of natural gas-fired condensing boilers. - Highlights: → Large-scale CHP systems are thermodynamically equivalent to virtual steam cycle heat pumps. → COPs of such virtual heat pumps are necessarily better than the Carnot limit for real heat pumps. → COPs can approach 9 for plant matched to district heating systems with flow temperatures of 90 deg. C. → CHP combined with CCGT and CCS can reduce the carbon intensity of delivered heat ∼30-fold.

  11. Thermodynamic Analysis of a Ship Power Plant Operating with Waste Heat Recovery through Combined Heat and Power Production

    Directory of Open Access Journals (Sweden)

    Mirko Grljušić

    2014-11-01

    Full Text Available The goal of this research is to study a cogeneration plant for combined heat & power (CHP production that utilises the low-temperature waste energy in the power plant of a Suezmax-size oil tanker for all heating and electricity requirements during navigation. After considering various configurations, a standard propulsion engine operating at maximum efficiency and a CHP Plant with R245fa fluid using a supercritical organic Rankine cycle (ORC is selected. All the ship heat requirements can be covered by energy of organic fluid after expansion in the turbine, except feeder-booster heating. Hence, an additional quantity of working fluid may be heated using an after Heat Recovery Steam Generator (HRSG directed to the feeder-booster module. An analysis of the obtained results shows that the steam turbine plant does not yield significant fuel savings. However, a CHP plant with R245fa fluid using supercritical ORC meets all of the demands for electrical energy and heat while burning only a small amount of additional fuel in HRSG at the main engine off-design operation.

  12. Modeling of high power ICRF heating experiments on TFTR

    International Nuclear Information System (INIS)

    Phillips, C.K.; Wilson, J.R.; Bell, M.; Fredrickson, E.; Hosea, J.C.; Majeski, R.; Ramsey, A.; Rogers, J.H.; Schilling, G.; Skinner, C.; Stevens, J.E.; Taylor, G.; Wong, K.L.; Murakami, M.

    1993-01-01

    Over the past two years, ICRF heating experiments have been performed on TFTR in the hydrogen minority heating regime with power levels reaching 11.2 MW in helium-4 majority plasmas and 8.4 MW in deuterium majority plasmas. For these power levels, the minority hydrogen ions, which comprise typically less than 10% of the total electron density, evolve into la very energetic, anisotropic non-Maxwellian distribution. Indeed, the excess perpendicular stored energy in these plasmas associated with the energetic minority tail ions is often as high as 25% of the total stored energy, as inferred from magnetic measurements. Enhanced losses of 0.5 MeV protons consistent with the presence of an energetic hydrogen component have also been observed. In ICRF heating experiments on JET at comparable and higher power levels and with similar parameters, it has been suggested that finite banana width effects have a noticeable effect on the ICRF power deposition. In particular, models indicate that finite orbit width effects lead to a reduction in the total stored energy and of the tail energy in the center of the plasma, relative to that predicted by the zero banana width models. In this paper, detailed comparisons between the calculated ICRF power deposition profiles and experimentally measured quantities will be presented which indicate that significant deviations from the zero banana width models occur even for modest power levels (P rf ∼ 6 MW) in the TFTR experiments

  13. 75 MW heat extraction from Beznau nuclear power plant (Switzerland)

    International Nuclear Information System (INIS)

    Handl, K.H.

    1998-01-01

    The district heat extraction system installed and commissioned at the Beznau Nuclear Power Plant 1983 and 1984 is working successfully since the beginning. Together with a six kilometres extension in 1994, the system now consists of a 35 kilometres main network and 85 kilometres of local distribution pipelines. The eight founding communities as well as three networks joined later have been connected. Today around 2160 consumers of the Refuna district heating, small and large private buildings, industrial and agricultural enterprises are supplied with heat from the Beznau plant (1997: 141'000 MWh). The regional district heat supply system has become an integrated part of the regional infrastructure for around 20'000 inhabitants of the lower Aare valley. Nearly 15 years of operational experience are confirming the success of the strict approval conditions for the housing connections. Remarkably deep return flow temperatures in the district heating network were leading to considerable reserves in the transport capacity of the main pipeline system. The impacts of the heat extraction from the Beznau nuclear power plant, in particular its contribution to the protection of the environment by substituting fossil fuels and preventing CO2-production, have been positive. (author)

  14. 46 CFR 129.550 - Power for cooking and heating.

    Science.gov (United States)

    2010-10-01

    ... INSTALLATIONS Miscellaneous Electrical Systems § 129.550 Power for cooking and heating. (a) Equipment for... with a thermal cut-out to prevent overheating. (e) Each element of an electric space-heater must be enclosed, and the case or jacket of the element made of a corrosion-resistant material. (f) Each electrical...

  15. Large power electron tubes for high frequency heating

    International Nuclear Information System (INIS)

    Okamoto, Tadashi; Sato, Hisaaki.

    1988-01-01

    On the large power electron tubes used for electron cyclotron heating, lower hybrid resonance frequency heating, and ion cyclotron range of frequency heating, namely gyrotron, klystron and quadrupole tube, the features, the present status of development, the construction, the principle and so on are explained. The research and development of gyrotrons are most advanced in USSR, the inventor. The course of the development of gyrotrons in foreign countries and in Japan is described. There are many variants of gyrotrons, for example whispering gallery mode, klystron type, backward wave oscillator type, gyro-peniotron and others. The principle of gyrotrons is explained, and about the examples of the developed gyrotrons, the design parameters are shown. For the purpose of using for the LHRF heating in JT-60, a superlarge power klystron of 1 MW output at 2 GHz frequency, which is the largest class in the world, has been developed. Its total length is 2.7 m, and weight is 1.5 t. It features, construction, function and performance are reported. The trend of large power quadrupole tubes is toward stable action with large power in VHF zone, and the typical products in USA and Europe are shown. (Kako, I.)

  16. Work and power fluctuations in a critical heat engine

    Science.gov (United States)

    Holubec, Viktor; Ryabov, Artem

    2017-09-01

    We investigate fluctuations of output work for a class of Stirling heat engines with working fluid composed of interacting units and compare these fluctuations to an average work output. In particular, we focus on engine performance close to a critical point where Carnot's efficiency may be attained at a finite power as reported by M. Campisi and R. Fazio [Nat. Commun. 7, 11895 (2016), 10.1038/ncomms11895]. We show that the variance of work output per cycle scales with the same critical exponent as the heat capacity of the working fluid. As a consequence, the relative work fluctuation diverges unless the output work obeys a rather strict scaling condition, which would be very hard to fulfill in practice. Even under this condition, the fluctuations of work and power do not vanish in the infinite system size limit. Large fluctuations of output work thus constitute inseparable and dominant element in performance of the macroscopic heat engines close to a critical point.

  17. Work and power fluctuations in a critical heat engine.

    Science.gov (United States)

    Holubec, Viktor; Ryabov, Artem

    2017-09-01

    We investigate fluctuations of output work for a class of Stirling heat engines with working fluid composed of interacting units and compare these fluctuations to an average work output. In particular, we focus on engine performance close to a critical point where Carnot's efficiency may be attained at a finite power as reported by M. Campisi and R. Fazio [Nat. Commun. 7, 11895 (2016)2041-172310.1038/ncomms11895]. We show that the variance of work output per cycle scales with the same critical exponent as the heat capacity of the working fluid. As a consequence, the relative work fluctuation diverges unless the output work obeys a rather strict scaling condition, which would be very hard to fulfill in practice. Even under this condition, the fluctuations of work and power do not vanish in the infinite system size limit. Large fluctuations of output work thus constitute inseparable and dominant element in performance of the macroscopic heat engines close to a critical point.

  18. Wind power integration in Aalborg Municipality using compression heat pumps and geothermal absorption heat pumps

    DEFF Research Database (Denmark)

    Østergaard, Poul Alberg

    2013-01-01

    -temperature geothermal resources. The analyses have also demonstrated that the municipality will still rely heavily on surrounding areas for electric load balancing assistance. With a departure in a previously elaborated 100% renewable energy scenario, this article investigates how absorption heat pumps (AHP......Aalborg Municipality, Denmark is investigating ways of switching to 100% renewable energy supply over the next 40 years. Analyses so far have demonstrated a potential for such a transition through energy savings, district heating (DH) and the use of locally available biomass, wind power and low......) and compression heat pumps (HP) for the supply of DH impact the integration of wind power. Hourly scenario-analyses made using the EnergyPLAN model reveal a boiler production and electricity excess which is higher with AHPs than with HPs whereas condensing mode power generation is increased by the application...

  19. A new method for distribution of consumed heat in a fuel and costs in power and heating plants

    Energy Technology Data Exchange (ETDEWEB)

    Kadrnozka, J [Technical Univ., Brno (Czech Republic)

    1993-09-01

    There is described a new method for distribution of consumed heat in a fuel and costs in the power and heating plants, which is based on the relatively the same proportion of advantages followed from combine generation of electricity and heat on electricity and heat. The method is physically substantiated, it is very universal and it is applied for new types of power and heating plants and for distribution of investment costs and other costs. (orig./GL)

  20. Development of low grade waste heat thermoelectric power generator

    Directory of Open Access Journals (Sweden)

    Suvit Punnachaiya

    2010-07-01

    Full Text Available This research aimed to develop a 50 watt thermoelectric power generator using low grade waste heat as a heat source,in order to recover and utilize the excess heat in cooling systems of industrial processes and high activity radioisotope sources. Electricity generation was based on the reverse operation of a thermoelectric cooling (TEC device. The TEC devices weremodified and assembled into a set of thermal cell modules operating at a temperature less than 100°C. The developed powergenerator consisted of 4 modules, each generating 15 watts. Two cascade modules were connected in parallel. Each modulecomprised of 96 TEC devices, which were connected in series. The hot side of each module was mounted on an aluminumheat transfer pipe with dimensions 12.212.250 cm. Heat sinks were installed on the cold side with cooling fans to provideforced air cooling.To test electricity generation in the experiment, water steam was used as a heat source instead of low grade waste heat.The open-circuit direct current (DC of 250 V and the short-circuit current of 1.2 A was achieved with the following operatingconditions: a hot side temperature of 96°C and a temperature difference between the hot and cold sides of 25°C. The DC poweroutput was inverted to an AC power source of 220 V with 50 Hz frequency, which can continuously supply more than 50 wattsof power to a resistive load as long as the heat source was applied to the system. The system achieved an electrical conversionefficiency of about 0.47 percent with the capital cost of 70 US$/W.

  1. Optimal power and efficiency of quantum Stirling heat engines

    Science.gov (United States)

    Yin, Yong; Chen, Lingen; Wu, Feng

    2017-01-01

    A quantum Stirling heat engine model is established in this paper in which imperfect regeneration and heat leakage are considered. A single particle which contained in a one-dimensional infinite potential well is studied, and the system consists of countless replicas. Each particle is confined in its own potential well, whose occupation probabilities can be expressed by the thermal equilibrium Gibbs distributions. Based on the Schrödinger equation, the expressions of power output and efficiency for the engine are obtained. Effects of imperfect regeneration and heat leakage on the optimal performance are discussed. The optimal performance region and the optimal values of important parameters of the engine cycle are obtained. The results obtained can provide some guidelines for the design of a quantum Stirling heat engine.

  2. Fuel cell - An alternative for power and heat generating

    International Nuclear Information System (INIS)

    Zubcu, Victor; Ursescu, Gabriel; Zubcu, Dorina Silvia; Miler, Mihai Cristian

    2004-01-01

    One of the most promising energy generating technologies is the fuel cell (FC) because of its high efficiency and low emissions. There are even zero chemical emissions FC and cogeneration plants based on FC generate low heat emissions too. FC was invented 160 years ago but it was usually used only since 1960 in space missions. A FC farm tractor was tested 40 years ago. FC was again taken into account by power engineering since 1990 and it is now considered a credible alternative to power and heat generating. The thermal power engineers (and not only they) have two problems of cardinal importance for mankind to solve: - Energy saving (by increasing of energy generating efficiency) and - Environmental protection (by reducing chemical and heat emissions). The possibilities to use FC to generate power and heat are practically endless: on the earth, in the air and outer space, by and under water, in numberless areas of human activities. FC are now powering buses, cars, trains, boats, plains, scooters, highway road signs etc. There are already miniature FC for portable electronics. Homes, schools, hospitals, institutes, banks, police stations, etc are using FC to generate power and heat for their facilities. The methane gas produced by wastewater treatment plants and landfills is converted into electricity by using FC. Being less expensive than nuclear and solar source of energy, FC is now generally used in the space missions (in addition FC generates water). In this work an analysis of the possibilities to use FC especially for combined power and heat generating is presented. FC is favourite as energy source in space missions because it is less expensive than nuclear or solar sources. All major automobile companies have FC powered automobiles in testing stage. Mini FC for phone, laptop, and electronics are already on market. FC will be use to pagers, video recorders, small portable tools, miniature robots, special devices as hearing aid various devices, smoke detectors

  3. Modeling of a District Heating System and Optimal Heat-Power Flow

    Directory of Open Access Journals (Sweden)

    Wentao Yang

    2018-04-01

    Full Text Available With ever-growing interconnections of various kinds of energy sources, the coupling between a power distribution system (PDS and a district heating system (DHS has been progressively intensified. Thus, it is becoming more and more important to take the PDS and the DHS as a whole in energy flow analysis. Given this background, a steady state model of DHS is first presented with hydraulic and thermal sub-models included. Structurally, the presented DHS model is composed of three major parts, i.e., the straight pipe, four kinds of local pipes, and the radiator. The impacts of pipeline parameters and the environment temperature on heat losses and pressure losses are then examined. The term “heat-power flow” is next defined, and the optimal heat-power flow (OHPF model formulated as a quadratic planning problem, in which the objective is to minimize energy losses, including the heat losses and active power losses, and both the operational constraints of PDS and DHS are respected. The developed OHPF model is solved by the well-established IPOPT (Interior Point OPTimizer commercial solver, which is based on the YALMIP/MATLAB toolbox. Finally, two sample systems are served for demonstrating the characteristics of the proposed models.

  4. Nuclear power and heating plant control rooms. I

    International Nuclear Information System (INIS)

    Malaniuk, B.

    1983-01-01

    The questions are discussed of memory capacity, vigilance, speed of data processing, decision-making quality and other demands placed on operators of nuclear power and heating plants. On the example of the accident at the Three Mile Island-2 nuclear power plant, the instants are shown when failure of the human factor owing to a stress situation resulted in the accident not being coped with in time. It is therefore necessary to place high demands on the choice of operators and to devote equal attention to the human factor as to the safety of the technical equipment of the power plant. (J.B.)

  5. Design and optimization of geothermal power generation, heating, and cooling

    Science.gov (United States)

    Kanoglu, Mehmet

    Most of the world's geothermal power plants have been built in 1970s and 1980s following 1973 oil crisis. Urgency to generate electricity from alternative energy sources and the fact that geothermal energy was essentially free adversely affected careful designs of plants which would maximize their performance for a given geothermal resource. There are, however, tremendous potentials to improve performance of many existing geothermal power plants by retrofitting, optimizing the operating conditions, re-selecting the most appropriate binary fluid in binary plants, and considering cogeneration such as a district heating and/or cooling system or a system to preheat water entering boilers in industrial facilities. In this dissertation, some representative geothermal resources and existing geothermal power plants in Nevada are investigated to show these potentials. Economic analysis of a typical geothermal resource shows that geothermal heating and cooling may generate up to 3 times as much revenue as power generation alone. A district heating/cooling system is designed for its incorporation into an existing 27 MW air-cooled binary geothermal power plant. The system as designed has the capability to meet the entire heating needs of an industrial park as well as 40% of its cooling needs, generating potential revenues of $14,040,000 per year. A study of the power plant shows that evaporative cooling can increase the power output by up to 29% in summer by decreasing the condenser temperature. The power output of the plant can be increased by 2.8 percent by optimizing the maximum pressure in the cycle. Also, replacing the existing working fluid isobutane by butane, R-114, isopentane, and pentane can increase the power output by up to 2.5 percent. Investigation of some well-known geothermal power generation technologies as alternatives to an existing 12.8 MW single-flash geothermal power plant shows that double-flash, binary, and combined flash/binary designs can increase the

  6. Cooling and heating facility for nuclear power plant

    International Nuclear Information System (INIS)

    Kakuta, Atsuro

    1994-01-01

    The present invention concerns a cooling and heating facility for a nuclear power plant. Namely, a cooling water supply system supplies cooling water prepared by a refrigerator for cooling the inside of the plant. A warm water supply system supplies warm water having its temperature elevated by using an exhausted heat from a reactor water cleanup system. The facility comprises a heat pump-type refrigerator disposed in a cold water supply system for producing cold water and warm water, and warm water pipelines for connecting the refrigerator and the warm water supply system. With such a constitution, when the exhaust heat from the reactor water cleanup system can not be used, warm water prepared by the heat pump type refrigerator is supplied to the warm water supply system by way of the warm water pipelines. Accordingly, when the exhaust heat from the reactor water cleanup system can not be used such as upon inspection of the plant, a portion of the refrigerators in a not-operated state can be used for heating. Supply of boiler steams in the plant is no more necessary or extremely reduced. (I.S.)

  7. Heating and current drive on NSTX

    Science.gov (United States)

    Wilson, J. R.; Batchelor, D.; Carter, M.; Hosea, J.; Ignat, D.; LeBlanc, B.; Majeski, R.; Ono, M.; Phillips, C. K.; Rogers, J. H.; Schilling, G.

    1997-04-01

    Low aspect ratio tokamaks pose interesting new challenges for heating and current drive. The NSTX (National Spherical Tokamak Experiment) device to be built at Princeton is a low aspect ratio toroidal device that has the achievement of high toroidal beta (˜45%) and non-inductive operation as two of its main research goals. To achieve these goals significant auxiliary heating and current drive systems are required. Present plans include ECH (Electron cyclotron heating) for pre-ionization and start-up assist, HHFW (high harmonic fast wave) for heating and current drive and eventually NBI (neutral beam injection) for heating, current drive and plasma rotation.

  8. Heating and current drive on NSTX

    International Nuclear Information System (INIS)

    Wilson, J.R.; Batchelor, D.; Carter, M.; Hosea, J.; Ignat, D.; LeBlanc, B.; Majeski, R.; Ono, M.; Phillips, C.K.; Rogers, J.H.; Schilling, G.

    1997-01-01

    Low aspect ratio tokamaks pose interesting new challenges for heating and current drive. The NSTX (National Spherical Tokamak Experiment) device to be built at Princeton is a low aspect ratio toroidal device that has the achievement of high toroidal beta (∼45%) and non-inductive operation as two of its main research goals. To achieve these goals significant auxiliary heating and current drive systems are required. Present plans include ECH (Electron cyclotron heating) for pre-ionization and start-up assist, HHFW (high harmonic fast wave) for heating and current drive and eventually NBI (neutral beam injection) for heating, current drive and plasma rotation. copyright 1997 American Institute of Physics

  9. Power enhancement of piezoelectric transformers by adding heat transfer equipment.

    Science.gov (United States)

    Su, Yu-Hao; Liu, Yuan-Ping; Vasic, Dejan; Wu, Wen-Jong; Costa, François; Lee, Chih-Kung

    2012-10-01

    It is known that piezoelectric transformers have several inherent advantages compared with conventional electromagnetic transformers. However, the maximum power capacity of piezoelectric transformers is not as large as electromagnetic transformers in practice, especially in the case of high output current. The theoretical power density of piezoelectric transformers calculated by stress boundary can reach 330 W/cm(3), but no piezoelectric transformer has ever reached such a high power density in practice. The power density of piezoelectric transformers is limited to 33 W/cm(3) in practical applications. The underlying reason is that the maximum passing current of the piezoelectric material (mechanical current) is limited by the temperature rise caused by heat generation. To increase this current and the power capacity, we proposed to add a thermal pad to the piezoelectric transformer to dissipate heat. The experimental results showed that the proposed techniques can increase by 3 times the output current of the piezoelectric transformer. A theoretical-phenomenological model which explains the relationship between vibration velocity and generated heat is also established to verify the experimental results.

  10. An effective heuristic for combined heat-and-power production planning with power ramp constraints

    International Nuclear Information System (INIS)

    Rong, Aiying; Lahdelma, Risto

    2007-01-01

    Combined heat-and-power (CHP) production is an increasingly important technology for its efficient utilization of primary-energy resources and for reducing CO 2 emissions. In the CHP plant, the generation of heat-and-power follows a joint characteristic, which makes the determination of both the marginal power production cost (MPPC) and the feasible operating region for the plant more complicated than for the power-only generation plant. Due to the interdependence between heat and power production, the power-ramp constraints, which limit how much the power production of a CHP plant may increase or decrease between two successive periods, may also imply constraints on the heat production. In this paper, we investigate the impact of power-ramp constraints on CHP production planning and develop a robust heuristic for dealing with the power-ramp constraints based on the solution to the problem with relaxed ramp-constraints (RRC). Numerical results based on realistic production models show that the heuristic can generate high-quality solutions efficiently. (author)

  11. Diamond-based heat spreaders for power electronic packaging applications

    Science.gov (United States)

    Guillemet, Thomas

    As any semiconductor-based devices, power electronic packages are driven by the constant increase of operating speed (higher frequency), integration level (higher power), and decrease in feature size (higher packing density). Although research and innovation efforts have kept these trends continuous for now more than fifty years, the electronic packaging technology is currently facing a challenge that must be addressed in order to move toward any further improvements in terms of performances or miniaturization: thermal management. Thermal issues in high-power packages strongly affect their reliability and lifetime and have now become one of the major limiting factors of power modules development. Thus, there is a strong need for materials that can sustain higher heat flux levels while safely integrating into the electronic package architecture. In such context, diamond is an attractive candidate because of its outstanding thermal conductivity, low thermal expansion, and high electrical resistivity. Its low heat capacity relative to metals such as aluminum or copper makes it however preferable for heat spreading applications (as a heat-spreader) rather than for dissipating the heat flux itself (as a heat sink). In this study, a dual diamond-based heat-spreading solution is proposed. Polycrystalline diamond films were grown through laser-assisted combustion synthesis on electronic substrates (in the U.S) while, in parallel, diamond-reinforced copper-matrix composite films were fabricated through tape casting and hot pressing (in France). These two types of diamond-based heat-spreading films were characterized and their microstructure and chemical composition were related to their thermal performances. Particular emphasize was put on the influence of interfaces on the thermal properties of the materials, either inside a single material (grain boundaries) or between dissimilar materials (film/substrate interface, matrix/reinforcement interface). Finally, the packaging

  12. Engineering design aspects of the heat-pipe power system

    International Nuclear Information System (INIS)

    Capell, B.M.; Houts, M.G.; Poston, D.I.; Berte, M.

    1997-10-01

    The Heat-pipe Power System (HPS) is a near-term, low-cost space power system designed at Los Alamos that can provide up to 1,000 kWt for many space nuclear applications. The design of the reactor is simple, modular, and adaptable. The basic design allows for the use of a variety of power conversion systems and reactor materials (including the fuel, clad, and heat pipes). This paper describes a project that was undertaken to develop a database supporting many engineering aspects of the HPS design. The specific tasks discussed in this paper are: the development of an HPS materials database, the creation of finite element models that will allow a wide variety of investigations, and the verification of past calculations

  13. Engineering design aspects of the heat-pipe power system

    Science.gov (United States)

    Capell, B. M.; Houts, M. G.; Poston, D. I.; Berte, M.

    1997-01-01

    The Heat-pipe Power System (HPS) is a near-term, low-cost space power system designed at Los Alamos that can provide up to 1,000 kWt for many space nuclear applications. The design of the reactor is simple, modular, and adaptable. The basic design allows for the use of a variety of power conversion systems and reactor materials (including the fuel, clad, and heat pipes). This paper describes a project that was undertaken to develop a database supporting many engineering aspects of the HPS design. The specific tasks discussed in this paper are: the development of an HPS materials database, the creation of finite element models that will allow a wide variety of investigations, and the verification of past calculations.

  14. Nuclear power and heating plants in the electric power system. Part I

    International Nuclear Information System (INIS)

    Kalincik, L.

    1975-01-01

    Procedures used and results obtained in the following works are described: Incorporation of the nuclear power plants in the power system in the long term perspective; physical limitations on the WWER 440 reactor power changes during fuel campaigns; evaluation of the consumption and start-up characteristics of WWER type nuclear power plants (2x440 MWe); evaluation of refuelling campaigns distribution of nuclear power plant units with regard to comprehensive control properties of nuclear power plants; the possibilities are investigated of the utilization of the WWER type reactor for heat supply in Czechoslovakia. (author)

  15. Temporary heat storage by using combined heat and power in supplementary lighted greenhouses Proceedings of the Third International Symposium on Artificial Lighting in Horticulture

    NARCIS (Netherlands)

    Huijs, J.P.G.

    1997-01-01

    Because of better utilization possibilities of the produced heat, decentrally located combined heat and power installations achieve a higher energetic efficiency than producing heat and power separately. However, efficiency depends considerably on synchronism of heat and electricity demand. Using a

  16. Entropy Generation of Desalination Powered by Variable Temperature Waste Heat

    Directory of Open Access Journals (Sweden)

    David M. Warsinger

    2015-10-01

    Full Text Available Powering desalination by waste heat is often proposed to mitigate energy consumption and environmental impact; however, thorough technology comparisons are lacking in the literature. This work numerically models the efficiency of six representative desalination technologies powered by waste heat at 50, 70, 90, and 120 °C, where applicable. Entropy generation and Second Law efficiency analysis are applied for the systems and their components. The technologies considered are thermal desalination by multistage flash (MSF, multiple effect distillation (MED, multistage vacuum membrane distillation (MSVMD, humidification-dehumidification (HDH, and organic Rankine cycles (ORCs paired with mechanical technologies of reverse osmosis (RO and mechanical vapor compression (MVC. The most efficient technology was RO, followed by MED. Performances among MSF, MSVMD, and MVC were similar but the relative performance varied with waste heat temperature or system size. Entropy generation in thermal technologies increases at lower waste heat temperatures largely in the feed or brine portions of the various heat exchangers used. This occurs largely because lower temperatures reduce recovery, increasing the relative flow rates of feed and brine. However, HDH (without extractions had the reverse trend, only being competitive at lower temperatures. For the mechanical technologies, the energy efficiency only varies with temperature because of the significant losses from the ORC.

  17. Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for Concentrating Solar Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Mathur, Anoop [Terrafore Inc.

    2013-08-14

    A key technological issue facing the success of future Concentrating Solar Thermal Power (CSP) plants is creating an economical Thermal Energy Storage (TES) system. Current TES systems use either sensible heat in fluids such as oil, or molten salts, or use thermal stratification in a dual-media consisting of a solid and a heat-transfer fluid. However, utilizing the heat of fusion in inorganic molten salt mixtures in addition to sensible heat , as in a Phase change material (PCM)-based TES, can significantly increase the energy density of storage requiring less salt and smaller containers. A major issue that is preventing the commercial use of PCM-based TES is that it is difficult to discharge the latent heat stored in the PCM melt. This is because when heat is extracted, the melt solidifies onto the heat exchanger surface decreasing the heat transfer. Even a few millimeters of thickness of solid material on heat transfer surface results in a large drop in heat transfer due to the low thermal conductivity of solid PCM. Thus, to maintain the desired heat rate, the heat exchange area must be large which increases cost. This project demonstrated that the heat transfer coefficient can be increase ten-fold by using forced convection by pumping a hyper-eutectic salt mixture over specially coated heat exchanger tubes. However,only 15% of the latent heat is used against a goal of 40% resulting in a projected cost savings of only 17% against a goal of 30%. Based on the failure mode effect analysis and experience with pumping salt at near freezing point significant care must be used during operation which can increase the operating costs. Therefore, we conclude the savings are marginal to justify using this concept for PCM-TES over a two-tank TES. The report documents the specialty coatings, the composition and morphology of hypereutectic salt mixtures and the results from the experiment conducted with the active heat exchanger along with the lessons learnt during

  18. Flexibility of a combined heat and power system with thermal energy storage for district heating

    International Nuclear Information System (INIS)

    Nuytten, Thomas; Claessens, Bert; Paredis, Kristof; Van Bael, Johan; Six, Daan

    2013-01-01

    Highlights: ► A generic model for flexibility assessment of thermal systems is proposed. ► The model is applied to a combined heat and power system with thermal energy storage. ► A centrally located storage offers more flexibility compared to individual units. ► Increasing the flexibility requires both a more powerful CHP and a larger buffer. - Abstract: The trend towards an increased importance of distributed (renewable) energy resources characterized by intermittent operation redefines the energy landscape. The stochastic nature of the energy systems on the supply side requires increased flexibility at the demand side. We present a model that determines the theoretical maximum of flexibility of a combined heat and power system coupled to a thermal energy storage solution that can be either centralized or decentralized. Conventional central heating, to meet the heat demand at peak moments, is also available. The implications of both storage concepts are evaluated in a reference district. The amount of flexibility created in the district heating system is determined by the approach of the system through delayed or forced operation mode. It is found that the distinction between the implementation of the thermal energy storage as a central unit or as a collection of local units, has a dramatic effect on the amount of available flexibility

  19. Beam heating requirements for a tokamak experimental power reactor

    International Nuclear Information System (INIS)

    Bertoncini, P.J.; Brooks, J.N.; Fasolo, J.A.; Stacey, W.M. Jr.

    1976-01-01

    Typical beam heating requirements for effective tokamak experimental power reactor (TEPR) operation have been studied in connection with the Argonne preliminary conceptual TEPR design. For an ignition level plasma (approximately 100 MWt fusion power) for the nominal case envisioned, the neutral beam is only used to heat the plasma to ignition. This typically requires a beam power output of 40 MW at 180 keV for about 3 sec with a total energy of 114 MJ supplied to the plasma. The beam requirements for an ignition device are not very sensitive to changes in wall-sputtered impurity levels or plasma resistivity. For a plasma that must be driven due to poor confinement, the beam must remain on for most of the burn cycle. For representative cases, beam powers of approximately 23 MW are required for a total on-time of 20 to 50 sec. Reqirements on power level, beam energy, on-time, and beam-generation efficiency all represent considerable advances over present technology. For the Argonne TEPR design, a total of 16 to 32 beam injectors is envisioned. For a 40-MW, 180-keV, one-component beam, each injector supplies about 7 to 14 A of neutrals to the plasma. For positive ion sources, about 50 to 100 A of ions are required per injector and some form of particle and/or energy recycling appears to be essential in order to meet the power and efficiency requirements

  20. Experimental investigation of thermoelectric power generation versus coolant pumping power in a microchannel heat sink

    DEFF Research Database (Denmark)

    Kolaei, Alireza Rezania; Rosendahl, Lasse; Andreasen, Søren Juhl

    2012-01-01

    The coolant heat sinks in thermoelectric generators (TEG) play an important role in order to power generation in the energy systems. This paper explores the effective pumping power required for the TEGs cooling at five temperature difference of the hot and cold sides of the TEG. In addition......, the temperature distribution and the pressure drop in sample microchannels are considered at four sample coolant flow rates. The heat sink contains twenty plate-fin microchannels with hydraulic diameter equal to 0.93 mm. The experimental results show that there is a unique flow rate that gives maximum net-power...

  1. Thermoeconomic Analysis of Hybrid Power Plant Concepts for Geothermal Combined Heat and Power Generation

    Directory of Open Access Journals (Sweden)

    Florian Heberle

    2014-07-01

    Full Text Available We present a thermo-economic analysis for a low-temperature Organic Rankine Cycle (ORC in a combined heat and power generation (CHP case. For the hybrid power plant, thermal energy input is provided by a geothermal resource coupled with the exhaust gases of a biogas engine. A comparison to alternative geothermal CHP concepts is performed by considering variable parameters like ORC working fluid, supply temperature of the heating network or geothermal water temperature. Second law efficiency as well as economic parameters show that hybrid power plants are more efficient compared to conventional CHP concepts or separate use of the energy sources.

  2. Power deposition for ion cyclotron heating in large tokamaks

    International Nuclear Information System (INIS)

    Hellsten, T.; Villard, L.

    1988-01-01

    The power deposition profiles during minority ion cyclotron heating are analysed in large tokamaks by using the global, toroidal wave code LION. For tokamaks with large aspect ratio and with circular cross-section, the wave is focused on the magnetic axis and can be absorbed there by cyclotron absorption when the cyclotron resonance passes through the magnetic axis. The power deposition profile is then essentially determined by the Doppler broadening of the ion cyclotron resonance. For equilibria either non-circular or with a small aspect ratio the power deposition profile depends also on the strength of the damping. In this case the power deposition profile can be expressed as a sum of two power deposition profiles. One is related to the power absorbed in a single pass, and its shape is similar to that obtained for large aspect ratio and circular cross-section. The other profile is obtained by calculating the power deposition in the limit of weak damping, in which case the wave electric field is almost constant along the cyclotron resonance layer. A heuristic formula for the power deposition is given. The formula includes a number of calibration curves and functions which has been calculated with the LION code for JET relevant equilibria. The formula enables calculation of the power deposition profile in a simple way when the launched wave spectrum and damping coefficients are known. (author). 7 refs, 11 figs

  3. A feasible system integrating combined heating and power system with ground-source heat pump

    International Nuclear Information System (INIS)

    Li, HongQiang; Kang, ShuShuo; Yu, Zhun; Cai, Bo; Zhang, GuoQiang

    2014-01-01

    A system integrating CHP (combined heating and power) subsystem based on natural gas and GSHP (ground-source heat pump subsystem) in series is proposed. By help of simulation software-Aspen Plus, the energy performance of a typical CHP and GSHP-S (S refers to ‘in series’) system was analyzed. The results show that the system can make a better use of waste heat in flue gas from CHP (combined heating and power subsystem). The total system energy efficiency is 123% and the COP (coefficient of performance) of GSHP (ground-source heat pump) subsystem is 5.3. A referenced CHP and GSHP-P (P refers to ‘in parallel’) system is used for comparison; its total system energy efficiency and COP of GSHP subsystem are 118.6% and 3.5 respectively. Compared with CHP and GSHP-P system with different operating parameters, the CHP and GSHP-S system can increase total system energy efficiency by 0.8–34.7%, with related output ratio of heat to power (R) from 1.9 to 18.3. Furthermore, the COP of GSHP subsystem can be increased between the range 3.6 and 6, which is much higher than that in conventional CHP and GSHP-P system. This study will be helpful for other efficient GSHP systems integrating if there is waste heat or other heat resources with low temperature. - Highlights: • CHP system based on natural gas and ground source heat pump. • The new system can make a better utilization of waste heat in flue gas by a special way. • The proposed system can realize energy saving potential from 0.8 to 34.7%. • The coefficient of performance of ground source heat pump subsystem is significantly improved from 3.5 to 3.6–6. • Warm water temperature and percentage of flue gas used to reheat are key parameters

  4. Heat exchangers for automotive gas turbine power plants

    International Nuclear Information System (INIS)

    Penny, R.N.

    1974-01-01

    Automotive gas turbine power plants are now in the final stages of development for quantity manufacture. A crucial factor in this development is the regenerative heat exchanger. The relative merits of the rotary regenerative and static recuperative heat exchanger are compared. Thermal efficiency and initial cost are two vital issues involved in the design of small gas turbines for the commercial establishment of gas turbine vehicles. The selection of a material for the rotaty regenerator is essentially related to resolving the two vital issues of future small gas turbines and is, therefore, analysed. The account of the pioneering work involved in engineering the glass ceramic and other non-metal regenerators includes a complete failure analysis based on running experience with over 200 ceramic regenerators. The problems of sealing, supporting and manufacturing the ceramic regenerator are discussed and future practical designs are outlined. Heat exchange theory applied to small gas turbines is also reviewed

  5. High-Temperature Reactor For Power Generation and District Heating

    International Nuclear Information System (INIS)

    Herzberger, Karlheinz

    1987-01-01

    The multinational BBC Brown Brave Group, which has its head-quarters in Baden/Switzerland, was founded in 1891. Its German company is Brown, Brave and CIEs AGM, Mannheim. The field of operation covers wide areas of electrical engineering: These includes mainly the manufacture of installations and equipment for the generation, conversion, distribution and utilization of electric power, with special emphasis on the capital goods sector. BBC erects turnkey power plants and manufactures electrical equipment for industrial plants and urban transport and main line trains. Also of major importance are standard electrical products such as motors, switches, cables, semiconductor devices as well as measuring and control equipment. In the field of nuclear power BBC is engaged in particular in the development and construction of high-temperature reactors for the generation of electric power and process heat. The following presentation gives a short view on the milestones of the HTR development achieved in 1987

  6. Power generation using sugar cane bagasse: A heat recovery analysis

    Science.gov (United States)

    Seguro, Jean Vittorio

    The sugar industry is facing the need to improve its performance by increasing efficiency and developing profitable by-products. An important possibility is the production of electrical power for sale. Co-generation has been practiced in the sugar industry for a long time in a very inefficient way with the main purpose of getting rid of the bagasse. The goal of this research was to develop a software tool that could be used to improve the way that bagasse is used to generate power. Special focus was given to the heat recovery components of the co-generation plant (economizer, air pre-heater and bagasse dryer) to determine if one, or a combination, of them led to a more efficient co-generation cycle. An extensive review of the state of the art of power generation in the sugar industry was conducted and is summarized in this dissertation. Based on this models were developed. After testing the models and comparing the results with the data collected from the literature, a software application that integrated all these models was developed to simulate the complete co-generation plant. Seven different cycles, three different pressures, and sixty-eight distributions of the flue gas through the heat recovery components can be simulated. The software includes an economic analysis tool that can help the designer determine the economic feasibility of different options. Results from running the simulation are presented that demonstrate its effectiveness in evaluating and comparing the different heat recovery components and power generation cycles. These results indicate that the economizer is the most beneficial option for heat recovery and that the use of waste heat in a bagasse dryer is the least desirable option. Quantitative comparisons of several possible cycle options with the widely-used traditional back-pressure turbine cycle are given. These indicate that a double extraction condensing cycle is best for co-generation purposes. Power generation gains between 40 and

  7. Combined Heat and Power Market Potential for Opportunity Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Jones, David [Resource Dynamics Corporation, McLean, VA (United States); Lemar, Paul [Resource Dynamics Corporation, McLean, VA (United States

    2015-12-01

    This report estimates the potential for opportunity fuel combined heat and power (CHP) applications in the United States, and provides estimates for the technical and economic market potential compared to those included in an earlier report. An opportunity fuel is any type of fuel that is not widely used when compared to traditional fossil fuels. Opportunity fuels primarily consist of biomass fuels, industrial waste products and fossil fuel derivatives. These fuels have the potential to be an economically viable source of power generation in various CHP applications.

  8. Large Combined Heat and Power Plants for Sustainable Energy System

    DEFF Research Database (Denmark)

    Lund, Rasmus Søgaard; Mathiesen, Brian Vad

    . CHP (combined heat and power) plants in Denmark will change their role from base load production to balancing the fluctuation in renewable energy supply, such as wind power and at the same time they have to change to renewable energy sources. Some solutions are already being planned by utilities...... in Denmark; conversion of pulverised fuel plants from coal to wood pellets and a circulating fluidised bed (CFB) plant for wood chips. From scientific research projects another solution is suggested as the most feasible; the combined cycle gas turbine (CCGT) plant. In this study a four scenarios...

  9. Thermal Energy Corporation Combined Heat and Power Project

    Energy Technology Data Exchange (ETDEWEB)

    Turner, E. Bruce [Thermal Energy Corporation, Houston, TX (United States); Brown, Tim [Thermal Energy Corporation, Houston, TX (United States); Mardiat, Ed [Burns and McDonnell Engineering Company, Inc., Kansas City, MI (United States)

    2011-12-31

    To meet the planned heating and cooling load growth at the Texas Medical Center (TMC), Thermal Energy Corporation (TECO) implemented Phase 1 of a Master Plan to install an additional 32,000 tons of chilled water capacity, a 75,000 ton-hour (8.8 million gallon) Thermal Energy Storage (TES) tank, and a 48 MW Combined Heat and Power (CHP) system. The Department of Energy selected TMC for a $10 million grant award as part of the Financial Assistance Funding Opportunity Announcement, U.S. Department of Energy National Energy Technology, Recovery Act: Deployment of Combined Heat and Power (CHP) Systems, District Energy Systems, Waste Energy Recovery Systems, and Efficiency Industrial Equipment Funding Opportunity Number: DE-FOA-0000044 to support the installation of a new 48 MW CHP system at the TMC located just outside downtown Houston. As the largest medical center in the world, TMC is home to many of the nation's best hospitals, physicians, researchers, educational institutions, and health care providers. TMC provides care to approximately six million patients each year, and medical instruction to over 71,000 students. A medical center the size of TMC has enormous electricity and thermal energy demands to help it carry out its mission. Reliable, high-quality steam and chilled water are of utmost importance to the operations of its many facilities. For example, advanced medical equipment, laboratories, laundry facilities, space heating and cooling all rely on the generation of heat and power. As result of this project TECO provides this mission critical heating and cooling to TMC utilizing a system that is both energy-efficient and reliable since it provides the capability to run on power independent of the already strained regional electric grid. This allows the medical center to focus on its primary mission providing top quality medical care and instruction without worrying about excessive energy costs or the loss of heating and cooling due to the risk of power

  10. Large-Scale Combined Heat and Power (CHP) Generation at Loviisa Nuclear Power Plant Unit 3

    International Nuclear Information System (INIS)

    Bergroth, N.

    2010-01-01

    Fortum has applied for a Decision in Principle concerning the construction of a new nuclear power plant unit (Loviisa 3) ranging from 2800-4600 MWth at its site located at the southern coast of Finland. An attractive alternative investigated is a co-generation plant designed for large-scale district heat generation for the Helsinki metropolitan area that is located approximately 75 km west of the site. The starting point is that the district heat generation capacity of 3 unit would be around 1 000 MWth.The possibility of generating district heat for the metropolitan area by Loviisa's two existing nuclear power plant units was investigated back in the 1980s, but it proved unpractical at the time. With the growing concern of the climate change and the subsequent requirements on heat and power generation, the idea is much more attractive today, when recognising its potential to decrease Finland's carbon dioxide emissions significantly. Currently the district heat generation in metropolitan area is based on coal and natural gas, producing some five to seven million tonnes of carbon dioxide emissions annually. Large-scale combined heat and power (CHP) generation at the 3 unit could cut this figure by up to four million tonnes. This would decrease carbon dioxide emissions by as much as six percent. In addition, large-scale CHP generation would increase the overall efficiency of the new unit significantly and hence, reduce the environmental impact on the local marine environment by cutting heat discharges into the Gulf of Nuclear energy has been used for district heating in several countries both in dedicated nuclear heating plants and in CHP generation plants. However, the heat generation capacity is usually rather limited, maximum being around 250 MWth per unit. Set against this, the 3 CHP concept is much more ambitious, not only because of the much larger heat generation output envisaged, but also because the district heating water would have to be transported over a

  11. A method for distributed power consumption based on the combined heat and power system

    Science.gov (United States)

    Li, Si-wei; Han, Shen-zhao; Yu, Bo; Lu, Xin; Qi, Wen

    2018-02-01

    With the development of the society and human progress, now resource problems has become one of the major problems faced by people all over the world, the development of new energy and clean energy is the priority now, is now the main power system. Winter heating is one of the main sources of pollution now, so it is very important to study the electric heating system.

  12. The Design of the Trading Mechanism to Adapt the Development of Mixed Cooling Heating and Power

    Science.gov (United States)

    Liu, D. N.; Li, Z. H.; Zhou, H. M.; Zhao, Q.; Xu, X. F.

    2017-08-01

    The enterprise who has combined cooling heating and power system has both the customer group and the power generation resources. Therefore, it can be used as a power user, and can also be used as a power generation enterprise to participate in the direct purchase of electricity. This paper combines characteristics of mixed cooling heating and power, designs application business model of mixed cooling heating and power, and puts forward to the scene of cooling heating and power trading scheme, helping the enterprise according to the power supply and demand situation in the region adjust their positions and participate in the electricity market.

  13. Study of Heating and Fusion Power Production in ITER Discharges

    International Nuclear Information System (INIS)

    Rafiq, T.; Kritz, A. H.; Bateman, G.; Kessel, C.; McCune, D. C.; Budny, R. V.; Pankin, A. Y.

    2011-01-01

    ITER simulations, in which the temperatures, toroidal angular frequency and currents are evolved, are carried out using the PTRANSP code starting with initial profiles and boundary conditions obtained from TSC code studies. The dependence of heat deposition and current drive on ICRF frequency, number of poloidal modes, beam orientation, number of Monte Carlo particles and ECRH launch angles is studied in order to examine various possibilities and contingencies for ITER steady state and hybrid discharges. For the hybrid discharges, the fusion power production and fusion Q, computed using the Multi-Mode MMM v7.1 anomalous transport model, are compared with those predicted using the GLF23 model. The simulations of the hybrid scenario indicate that the fusion power production at 1000 sec will be approximately 500 MW corresponding to a fusion Q = 10.0. The discharge scenarios simulated aid in understanding the conditions for optimizing fusion power production and in examining measures of plasma performance.

  14. Thermal Heat and Power Production with Models for Local and Regional Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Saether, Sturla

    1999-07-01

    The primary goal of this thesis is the description and modelling of combined heat and power systems as well as analyses of thermal dominated systems related to benefits of power exchange. Large power plants with high power efficiency (natural gas systems) and heat production in local heat pumps can be favourable in areas with low infrastructure of district heating systems. This system is comparable with typical combined heat and power (CHP) systems based on natural gas with respect to efficient use of fuel energy. The power efficiency obtainable from biomass and municipal waste is relatively low and the advantage of CHP for this system is high compared to pure power production with local heat pumps for heat generation. The advantage of converting pure power systems into CHP systems is best for power systems with low power efficiency and heat production at low temperature. CHP systems are divided into two main groups according to the coupling of heat and power production. Some CHP systems, especially those with strong coupling between heat and power production, may profit from having a thermal heat storage subsystem. District heating temperatures direct the heat to power ratio of the CHP units. The use of absorption chillers driven by district heating systems are also evaluated with respect to enhancing the utilisation of district heating in periods of low heat demand. Power exchange between a thermal dominated and hydropower system is found beneficial. Use of hydropower as a substitute for peak power production in thermal dominated systems is advantageous. Return of base load from the thermal dominated system to the hydropower system can balance in the net power exchange.

  15. Opportunities for Combined Heat and Power in Data Centers

    Energy Technology Data Exchange (ETDEWEB)

    Darrow, Ken [ICF International; Hedman, Bruce [ICF International

    2009-03-01

    types of facilities involved, and the geographic distribution. (2) Data Center Energy Use Trends--a discussion of energy use and expected energy growth and the typical energy consumption and uses in data centers. (3) CHP Applicability--Potential configurations, CHP case studies, applicable equipment, heat recovery opportunities (cooling), cost and performance benchmarks, and power reliability benefits (4) CHP Drivers and Hurdles--evaluation of user benefits, social benefits, market structural issues and attitudes toward CHP, and regulatory hurdles. (5) CHP Paths to Market--Discussion of technical needs, education, strategic partnerships needed to promote CHP in the IT community.

  16. Heat sink design considerations in medium power electronic applications with long power cycles

    CERN Document Server

    AUTHOR|(SzGeCERN)744611; Papastergiou, Konstantinos; Thiringer, Torbjörn; Bongiorno, Massimo

    2015-01-01

    The aim of this work is to investigate the impact of the heat sink thickness and material, as well as, of the convection coefficient of the water cooling system on the power-electronics module thermal stressing. The heat extraction capability of different thicknesses is tested. It is concluded that the thickest heat sink results in marginally lower temperature variation at the junction level compared to the second thickest one. In the thickest heat sink case, the linear dependence of the thermal resistance on the thickness counteracts the benefit of the increased thermal capacitance. The increase in the cooling medium flow rate, which corresponds to an increase in the convection coefficient between the heat sink bottom surface and the water, can be avoided by increasing the thickness of the heat sink. In this way, the energy consumption of the cooling system is reduced. The increase in the flow rate drastically reduces the thermal stressing in the thinnest heat sink case. The increase of the heat sink thickne...

  17. Prospects of heat supply from Temelin nuclear power plant

    International Nuclear Information System (INIS)

    Kuba, V.

    1987-01-01

    The possibilities are discussed of using the Temelin nuclear power plant for heat supply to a number of localities in the South Bohemian Region, to a distance of up to 34 km. Direct supply of steam and of 150/70 degC or 180/65 degC hot water is envisaged. An alternative solution has also been proposed allowing to supply steam and hot water simultaneously from 180 degC hot water with quantitative regulation. The hot water is made to expand at a pressure of 0.3 to 0.5 MPa and the low-pressure steam is compressed to a pressure of 0.9 to 1.3 MPa. This steam will be supplied to the existing heating system. The possibility was also studied of supplying Prague with heat and 180/65 degC hot water of a thermal output of up to 1,700 MW using a two-pipe heat supply line of 105 to 125 km in length. (B.S.). 2 figs

  18. Evaluation of the performance of combined cooling, heating, and power systems with dual power generation units

    International Nuclear Information System (INIS)

    Knizley, Alta A.; Mago, Pedro J.; Smith, Amanda D.

    2014-01-01

    The benefits of using a combined cooling, heating, and power system with dual power generation units (D-CCHP) is examined in nine different U.S. locations. One power generation unit (PGU) is operated at base load while the other is operated following the electric load. The waste heat from both PGUs is used for heating and for cooling via an absorption chiller. The D-CCHP configuration is studied for a restaurant benchmark building, and its performance is quantified in terms of operational cost, primary energy consumption (PEC), and carbon dioxide emissions (CDE). Cost spark spread, PEC spark spread, and CDE spark spread are examined as performance indicators for the D-CCHP system. D-CCHP system performance correlates well with spark spreads, with higher spark spreads signifying greater savings through implementation of a D-CCHP system. A new parameter, thermal difference, is introduced to investigate the relative performance of a D-CCHP system compared to a dual PGU combined heat and power system (D-CHP). Thermal difference, together with spark spread, can explain the variation in savings of a D-CCHP system over a D-CHP system for each location. The effect of carbon credits on operational cost savings with respect to the reference case is shown for selected locations. - Highlights: • We investigate benefits from using combined cooling, heating, and power systems. • A dual power generation unit configuration is considered for CCHP and CHP. • Spark spreads for cost, energy, and emissions correlate with potential savings. • Thermal difference parameter helps to explain variations in potential savings. • Carbon credits may increase cost savings where emissions savings are possible

  19. The ohmic heating power supply for HL-1 tokamak

    International Nuclear Information System (INIS)

    Mingrui, Z.; Jiashun, C.

    1986-01-01

    A combination of capacitor banks, inductor and DC Fly wheel-Generator sets are used as ohmic heating power supply (OHPS) for HL-1, which is the largest tokamak in China. This system can give changeable waveform of current in a simple way, because of the use of protection for capacitor banks by changeable connection in easy way. Since the technology of forced zero current in the commutating breaker and synchronous self-triggering crowbar are used, the smooth conversion between the wave front provided by discharge of the capacitor banks and the flat top sustained by the inductor and flywheel realized. The performance of the system was tested by a dummy load and the system has been used in the HL-1 experiments. It is confirmed that this system is sufficiently available for the ohmic heating and has important effects on the long plasma lasting time on the order of 1 sec

  20. Combined heat and power in industry and buildings

    International Nuclear Information System (INIS)

    Hinnells, Mark

    2008-01-01

    Combined heat and power (CHP) has huge potential to deliver energy savings and emissions reductions, and in many cases cost reductions too. But the market and regulatory framework is the key to delivering large-scale installations, and government has a poor record in delivering an appropriate framework. Technology is central to the future competitiveness and therefore uptake of CHP. It could lead to more efficient CHP electricity generation, permit the use of lower-carbon, renewable fuels, and enable the development of new products for new end uses, including micro-CHP and CHP in heat networks. The market for CHP has been difficult in the past few years, largely as a result of government market reforms. The UK's level of CHP skills, for installing current technologies and developing new ones, is low. The key issue is the creation of the right market framework to deliver CHP, and part of this is support for the energy services approach

  1. Maximum Power Output of Quantum Heat Engine with Energy Bath

    Directory of Open Access Journals (Sweden)

    Shengnan Liu

    2016-05-01

    Full Text Available The difference between quantum isoenergetic process and quantum isothermal process comes from the violation of the law of equipartition of energy in the quantum regime. To reveal an important physical meaning of this fact, here we study a special type of quantum heat engine consisting of three processes: isoenergetic, isothermal and adiabatic processes. Therefore, this engine works between the energy and heat baths. Combining two engines of this kind, it is possible to realize the quantum Carnot engine. Furthermore, considering finite velocity of change of the potential shape, here an infinite square well with moving walls, the power output of the engine is discussed. It is found that the efficiency and power output are both closely dependent on the initial and final states of the quantum isothermal process. The performance of the engine cycle is shown to be optimized by control of the occupation probability of the ground state, which is determined by the temperature and the potential width. The relation between the efficiency and power output is also discussed.

  2. Atmospheric effects of heat release at large power plants

    International Nuclear Information System (INIS)

    Kikuchi, Yukio

    1979-01-01

    In power plants, the thermal efficiency of generating electricity is generally 1/3, the rest 2/3 being carried away by cooling water. To release the heat, there are three alternative methods; i.e. cooling water released into sea, cooling water released into a cooling pond, and cooling of such water with a cooling tower. In the third method, cooling towers are stacks of 10m -- 80m bore, and warm cooling water flowing on the side wall is cooled with atmospheric air. The resultant heated air is discharged as plume from their top. Upon condensation, it becomes visible and then leads to the formation of clouds. In this manner, the weather around the sites of power plants is affected, such as reduction of insolation reaching ground and increase in precipitation. The following matters are described: cooling towers; phenomena and prediction methods of visible plume, cloud formation, increase of precipitation and deposition of drifting waterdrops; and effects of the group of power plants. (J.P.N.)

  3. Reliability evaluation of power supply and distribution for special heat removal systems in nuclear power stations

    International Nuclear Information System (INIS)

    Jazbec, D.

    1982-01-01

    An example of the power supply and distribution of a Special Emergency Heat Removal System (SEHR) shows how an engineering organization may, with the aid of the analytical method of min-cut sets optimize the system reliability. Herein are given the necessary simple calculation methods. (Auth.)

  4. Review of European regulatory and tariff experience with the sale of heat and electricity from combined heat and power plants

    International Nuclear Information System (INIS)

    Dyrelund, A.

    1991-12-01

    The Prince Edward Island Energy Corporation, Edmonton Power, Energy, Mines and Resources Canada and the Canadian Electrical Association commissioned a study to understand how electrical power and district heat from combined heat and power (CHP) plants is priced in Europe. Four northern European countries were investigated, Denmark, Germany, Sweden and Finland. These countries produce 45.8 TWh of power from combined heat and power plants, 7.1% of their annual consumption. In the case of Denmark, CHP accounts for 37.5% of its total power production. The energy situation in each country is reviewed using published statistics, and in particular the rapidly changing situation with regard to environmental and fuel taxes is examined. In order to obtain practical insights with regard to tariffs used by the various utilities, a series of generic examples were examined, supported by specific case studies. Technologies reviewed included: CHP from coal-fuelled extraction plant, CHP from coal-fuelled back pressure plant, waste heat from a municipal waste plant, and gas turbine with waste heat recovery. The benefits and risks associated with different tariff designs are discussed in detail including tariff formulae. This should enable interested parties to develop appropriate tariffs for combined heat and power plants in the context of current electrical utility policies. As a complement to the tariffs for combined heat and power plants, the design of district heating tariffs is also addressed. The typical concepts used in different countries are presented and discussed. 23 tabs

  5. WORKING PARK-FUEL CELL COMBINED HEAT AND POWER SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Allan Jones

    2003-09-01

    This report covers the aims and objectives of the project which was to design, install and operate a fuel cell combined heat and power (CHP) system in Woking Park, the first fuel cell CHP system in the United Kingdom. The report also covers the benefits that were expected to accrue from the work in an understanding of the full technology procurement process (including planning, design, installation, operation and maintenance), the economic and environmental performance in comparison with both conventional UK fuel supply and conventional CHP and the commercial viability of fuel cell CHP energy supply in the new deregulated energy markets.

  6. The agricultural use of heat discharge by nuclear power plants

    International Nuclear Information System (INIS)

    Grauby, A.; Delmas, J.; Foulquier, L.; Guillermin, R.

    1977-01-01

    At a time in which energy savings are of prime importance, it is interesting to be able to offer a technique enabling the use of the heated waters leaving the cooling circuits of electric power plants. Satisfactory and positive results have been obtained by the Environmental Research Service, in the area of open field farming as well as in pisciculture. The use of a network of buried pipes conveying the hot water leads to greater crop yields, off-season scheduling of early and late varieties to benefit from favorable market prices, together with the possibility of adapting priority industrial crops such as soya to our climates [fr

  7. Stochastic analysis of residential micro combined heat and power system

    DEFF Research Database (Denmark)

    Karami, H.; Sanjari, M. J.; Gooi, H. B.

    2017-01-01

    In this paper the combined heat and power functionality of a fuel-cell in a residential hybrid energy system, including a battery, is studied. The demand uncertainties are modeled by investigating the stochastic load behavior by applying Monte Carlo simulation. The colonial competitive algorithm...... algorithm. The optimized scheduling of different energy resources is listed in an efficient look-up table for all time intervals. The effects of time of use and the battery efficiency and its size are investigated on the operating cost of the hybrid energy system. The results of this paper are expected...

  8. Cost-benefit analysis for combined heat and power plant

    International Nuclear Information System (INIS)

    Sazdovski, Ace; Fushtikj, Vangel

    2004-01-01

    The paper presents a methodology and practical application of Cost-Benefit Analysis for Combined Heat and Power Plant (Cogeneration facility). Methodology include up-to-date and real data for cogeneration plant in accordance with the trends ill development of the CHP technology. As a case study a CHP plant that could be built-up in Republic of Macedonia is analyzed. The main economic parameters for project evaluation, such as NPV and IRR are calculated for a number of possible scenarios. The analyze present the economic outputs that could be used as a decision for CHP project acceptance for investment. (Author)

  9. Aging management guideline for commercial nuclear power plants - heat exchangers

    International Nuclear Information System (INIS)

    Booker, S.; Lehnert, D.; Daavettila, N.; Palop, E.

    1994-06-01

    This Aging Management Guideline (AMG) describes recommended methods for effective detection and mitigation of age-related degradation mechanisms in commercial nuclear power plant heat exchangers important to license renewal. The intent of this AMG is to assist plant maintenance and operations personnel in maximizing the safe, useful life of these components. It also supports the documentation of effective aging management programs required under the License Renewal Rule 10 CFR 54. This AMG is presented in a manner that allows personnel responsible for performance analysis and maintenance to compare their plant-specific aging mechanisms (expected or already experienced) and aging management program activities to the more generic results and recommendations presented herein

  10. Aging management guideline for commercial nuclear power plants - heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Booker, S.; Lehnert, D.; Daavettila, N.; Palop, E.

    1994-06-01

    This Aging Management Guideline (AMG) describes recommended methods for effective detection and mitigation of age-related degradation mechanisms in commercial nuclear power plant heat exchangers important to license renewal. The intent of this AMG is to assist plant maintenance and operations personnel in maximizing the safe, useful life of these components. It also supports the documentation of effective aging management programs required under the License Renewal Rule 10 CFR 54. This AMG is presented in a manner that allows personnel responsible for performance analysis and maintenance to compare their plant-specific aging mechanisms (expected or already experienced) and aging management program activities to the more generic results and recommendations presented herein.

  11. Economic and safety aspects of using moderator heat for feed water heating in a nuclear power plant

    International Nuclear Information System (INIS)

    Patwegar, I.A.; Dutta, Anu; Chaki, S.K.; Venkat Raj, V.

    2002-01-01

    Full text: In the proposed advanced heavy water reactor (AHWR), coolant and moderator are separated by the coolant channel. The coolant absorbs most of the fission heat produced in the reactor core. However, the moderator absorbs about 5 to 6 % of the fission heat. In a reactor producing 750 MW(th) power, this moderator heat is about 40 MW. In the present Indian PHWR (pressurized heavy water reactor) systems, this moderator heat is lost to a sink through the moderator heat exchangers, which are cooled by process water. This paper presents the results of the steam cycle analysis carried out for AHWR using moderator heat exchangers as part of the feed heating system. The present study is an attempt to determine the gain in electrical output (MW) if moderator heat is utilized for feed water heating. The operational and safety aspects of using moderator heat are also discussed in the paper

  12. Conversion of medium and low temperature heat to power

    Science.gov (United States)

    Fischer, Johann; Wendland, Martin; Lai, Ngoc Anh

    2013-04-01

    Presently most electricity is produced in power plants which use high temperature heat supplied by coal, oil, gas or nuclear fission and Clausius-Rankine cycles (CRC) with water as working fluid (WF). On the other hand, geo-, solar-, ocean-, and biogenic-heat have medium and low temperatures. At these temperatures, however, the use of other WF and/or other cycles can yield higher efficiencies than those of the water-CRC. For an assessment of the efficiency we model systems which include the heat transfer to and from the WF and the cycle. Optimization criterion is the exergy efficiency defined as the ratio of the net power output to the incoming exergy flow of the heat carrier. First, for a better understanding we discuss some thermodynamic properties of the WFs: 1) the critical point parameters, 2) the shape of the vapour- liquid coexistence curve in the temperature vs entropy (T,s)-diagram which may be either bell-shaped or overhanging [1,2], and 3) the shape of sub- and supercritical isobars for pure fluids and fluid mixtures. Second, we show that the problems of a CRC with water at lower temperatures are 1) the shape of the T,s-diagram and 2) the exergy loss during heat transfer to the WF. The first problem can be overcome by using an organic working fluid in the CRC which then is called organic Rankine cycle (ORC). The second problem is reduced by supercritical organic Rankine cycles (sORC) [1,2], trilateral cycles (TLC) and the more general power-flash cycles (PFC) [2], and organic flash cycles (OFC) [3]. Next, selected results for systems with the above mentioned cycles will be presented. The heat carrier inlet temperatures THC range from 120°C to 350°C.The pure working fluids are water, refrigerants, alkanes, aromates and siloxanes and have to be selected to match with THC. It is found that TLC with water have the highest efficiencies but show very large volume flows at lower temperatures. Moreover, expansion machines for TLC and PFC are still under

  13. The maximum power condition of the brayton cycle with heat exchange processes

    International Nuclear Information System (INIS)

    Jung, Pyung Suk; Cha, Jin Girl; Ro, Sung Tack

    1985-01-01

    The ideal brayton cycle has been analyzed with the heat exchange processes between the working fluid and the heat source and the sink while their heat capacity rates are constant. The power of the cycle can be expressed in terms of a temperature of the cycle and the heat capacity rate of the working fluid. There exists an optimum power condition where the heat capacity rate of the working fluid has a value between those of the heat source and the heat sink, and the cycle efficiency is determined by the inlet temperatures of the heat source and the sink. (Author)

  14. On heat transfer of weakly compressible power-law flows

    Directory of Open Access Journals (Sweden)

    Li Botong

    2017-01-01

    Full Text Available This paper completes a numerical research on steady momentum and heat transfer in power-law fluids in a channel. Weakly compressible laminar fluids are studied with no slip at the walls and uniform wall temperatures. The full governing equations are solved by continuous finite element method. Three thermal conductivity models are adopted in this paper, that is, constant thermal conductivity model, thermal conductivity varying as a function of temperature gradient, and a modified temperature-gradient-dependent thermal conductivity model. The results are compared with each other and the physical characteristics for values of parameters are also discussed in details. It is shown that the velocity curve from the solution becomes straight at higher power-law index. The effects of Reynolds numbers on the dilatant fluid and the pseudo-plastic look similar to each other and their trends can be easily predicted. Furthermore, for different models, the temperature curves also present pseudo-plastic and dilatant properties.

  15. Energy Conversion Advanced Heat Transport Loop and Power Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Oh, C. H.

    2006-08-01

    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, 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, 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. Three configurations of the power conversion unit were demonstrated in this study. A three-shaft design with 3 turbines and 4 compressors, a combined cycle with a Brayton top cycle and a Rankine bottoming cycle, and a reheated cycle with 3 stages of reheat were investigated. An intermediate heat transport loop for transporting process heat to a High Temperature Steam Electrolysis (HTSE) hydrogen production plant was used. Helium, CO2, and an 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 size were estimated for the different working fluids. The relative size of the turbomachinery was measured by comparing the power input/output of the component. For heat exchangers the volume was computed and compared. Parametric studies away from the baseline values of the three-shaft and combined cycles were performed to determine the effect of varying conditions in the cycle. This gives some insight into the sensitivity of these cycles to various

  16. Small-Scale Combined Heat and Power Plants Using Biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Salomon-Popa, Marianne [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Energy Technology

    2002-11-01

    In this time period where energy supply and climate change are of special concern, biomass-based fuels have attracted much interest due to their plentiful supply and favorable environmental characteristics (if properly managed). The effective capture and continued sustainability of this renewable resource requires a new generation of biomass power plants with high fuel energy conversion. At the same time, deregulation of the electricity market offers new opportunities for small-scale power plants in a decentralized scheme. These two important factors have opened up possibilities for small-scale combined heat and power (CHP) plants based on biofuels. The objective of this pre-study is to assess the possibilities and technical limitations for increased efficiency and energy utilization of biofuels in small size plants (approximately 10 MWe or lower). Various energy conversion technologies are considered and proven concepts for large-scale fossil fuel plants are an especially important area. An analysis has been made to identify the problems, technical limitations and different possibilities as recognized in the literature. Beyond published results, a qualitative survey was conducted to gain first-hand, current knowledge from experts in the field. At best, the survey results together with the results of personal interviews and a workshop on the role of small-scale plants in distributed generation will serve a guideline for future project directions and ideas. Conventional and novel technologies are included in the survey such as Stirling engines, combustion engines, gas turbines, steam turbines, steam motors, fuel cells and other novel technologies/cycles for biofuels. State-of-the-art heat and power plants will be identified to clarify of the advantages and disadvantages as well as possible obstacles for their implementation.

  17. Power-heat coupling plant of the Hacker-Pschorr Braeu AG, Munich

    Energy Technology Data Exchange (ETDEWEB)

    Treiber, K

    1978-01-01

    The power-heat co-generation plan of a large-scale brewery is specified. The specific heat consumption, the cost of in-house power generation, and cost savings gained are determined. In-house power costs and extraneous power costs are contrasted.

  18. Power balance in an Ohmically heated fusion reactor

    International Nuclear Information System (INIS)

    Christiansen, J.P.; Roberts, K.V.

    1982-01-01

    A simplified power-balance equation (zero-dimensional model) is used to study the performance of an Ohmically heated fusion reactor with emphasis on a pulsed reversed-field pinch concept (RFP). The energy confinement time tausub(E) is treated as an adjustable function, and empirical tokamak scaling laws are employed in the numerical estimates, which are supplemented by 1-D ATHENE code calculations. The known heating rates and energy losses are represented by the net energy replacement time tausub(W), which is exhibited as a surface in density (n) and temperature (T) space with a saddle point (nsub(*), Tsub(*)), the optimum ignition point. It is concluded that i) ignition by Ohmic heating is more practicable for the RFP reactor than for a tokamak reactor with the same tausub(E), (ii) if at fixed current the minor radius can be reduced or at fixed minor radius the current can be increased, then it is found that Ohmic ignition becomes more likely when present tokamak scaling laws are used. More definitive estimates require, however, a knowledge of tausub(E), which can only be obtained by establishing a reliable set of experimental RFP scaling laws and, in particular, by extending RFP experiments closer to the reactor regime. (author)

  19. Potential use of power plant reject heat in commercial aquaculture

    Energy Technology Data Exchange (ETDEWEB)

    Olszewski, M.

    1977-01-01

    Current research and commercial activities in aquaculture operations have been reviewed. An aquaculture system using mostly herbivorous species in pond culture is proposed as a means of using waste heat to produce reasonably priced protein. The system uses waste water streams, such as secondary sewage effluent, animal wastes, or some industrial waste streams as a primary nutrient source to grow algae, which is fed to fish and clams. Crayfish feed on the clam wastes thereby providing a clean effluent from the aquaculture system. Alternate fish associations are presented and it appears that a carp or tilapia association is desirable. An aquaculture system capable of rejecting all the waste heat from a 1000-MW(e) power station in winter can accommodate about half the summer heat rejection load. The aquaculture facility would require approximately 133 ha and would produce 4.1 x 10/sup 5/ kg/year of fish, 1.5 x 10/sup 6/ kg/year of clam meat, and 1.5 x 10/sup 4/ kg/year of live crayfish. The estimated annual pretax profit from this operation is one million dollars. Several possible problem areas have been identified. However, technical solutions appear to be readily available to solve these problems. The proposed system shows considerable economic promise. Small scale experiments have demonstrated the technical feasibility of various components of the system. It therefore appears that a pilot scale experimental facility should be operated.

  20. Combined cycle power plant with integrated low temperature heat (LOTHECO)

    International Nuclear Information System (INIS)

    Kakaras, E.; Doukelis, A.; Leithner, R.; Aronis, N.

    2004-01-01

    The major driver to enhance the efficiency of the simple gas turbine cycle has been the increase in process conditions through advancements in materials and cooling methods. Thermodynamic cycle developments or cycle integration are among the possible ways to further enhance performance. The current paper presents the possibilities and advantages from the LOTHECO natural gas-fired combined cycle concept. In the LOTHECO cycle, low-temperature waste heat or solar heat is used for the evaporation of injected water droplets in the compressed air entering the gas turbine's combustion chamber. Following a description of this innovative cycle, its advantages are demonstrated by comparison between different gas turbine power generation systems for small and large-scale applications, including thermodynamic and economic analysis. A commercial gas turbine (ALSTOM GT10C) has been selected and computed with the heat mass balance program ENBIPRO. The results from the energy analysis are presented and the features of each concept are discussed. In addition, the exergy analysis provides information on the irreversibilities of each process and suggested improvements. Finally, the economic analysis reveals that the combined cycle plant with a heavy-duty gas turbine is the most efficient and economic way to produce electricity at base load. However, on a smaller scale, innovative designs, such as the LOTHECO concept, are required to reach the same level of performance at feasible costs

  1. Emission operational strategy for combined cooling, heating, and power systems

    International Nuclear Information System (INIS)

    Fumo, Nelson; Mago, Pedro J.; Chamra, Louay M.

    2009-01-01

    Integrated Energy Systems (IES), as technology that use thermal activated components to recover waste heat, are energy systems that offer key solution to global warming and energy security through high overall energy efficiency and better fuel use. Combined Cooling, Heating, and Power (CCHP) Systems are IES that use recovered thermal energy from the prime mover to produce heating and cooling for the building. The CCHP operational strategy is critical and it has to be considered in a well designed system since it defines the ultimate goal for the benefits expected from the system. One of the most common operational strategies is the cost-oriented strategy, which allows the system to operate at the lowest cost. A primary energy strategy (PES) optimizes energy consumption instead of cost. However, as a result of the worldwide concern about global warming, projects that target reduction of greenhouse gas (GHG) emissions have gained a lot of interest. Therefore, for a CCHP system, an emission strategy (ES) would be an operational strategy oriented to minimize emission of pollutants. In this study, the use of an ES is proposed for CCHP systems targeted to reduce emission of pollutants. The primary energy consumption (PEC) reduction and carbon dioxide (CO 2 ) emission reduction obtained using the proposed ES are compared with results obtained from the use of a PES. Results show that lower emission of CO 2 is achieved with the ES when compared with the PES, which prove the advantage of the ES for the design of CCHP systems targeted to emissions reduction.

  2. Potential use of power plant reject heat in commercial aquaculture

    International Nuclear Information System (INIS)

    Olszewski, M.

    1977-01-01

    Current research and commercial activities in aquaculture operations have been reviewed. An aquaculture system using mostly herbivorous species in pond culture is proposed as a means of using waste heat to produce reasonably priced protein. The system uses waste water streams, such as secondary sewage effluent, animal wastes, or some industrial waste streams as a primary nutrient source to grow algae, which is fed to fish and clams. Crayfish feed on the clam wastes thereby providing a clean effluent from the aquaculture system. Alternate fish associations are presented and it appears that a carp or tilapia association is desirable. An aquaculture system capable of rejecting all the waste heat from a 1000-MW(e) power station in winter can accommodate about half the summer heat rejection load. The aquaculture facility would require approximately 133 ha and would produce 4.1 x 10 5 kg/year of fish, 1.5 x 10 6 kg/year of clam meat, and 1.5 x 10 4 kg/year of live crayfish. The estimated annual pretax profit from this operation is one million dollars. Several possible problem areas have been identified. However, technical solutions appear to be readily available to solve these problems. The proposed system shows considerable economic promise. Small scale experiments have demonstrated the technical feasibility of various components of the system. It therefore appears that a pilot scale experimental facility should be operated

  3. Optimization of powered Stirling heat engine with finite speed thermodynamics

    International Nuclear Information System (INIS)

    Ahmadi, Mohammad H.; Ahmadi, Mohammad Ali; Pourfayaz, Fathollah; Bidi, Mokhtar; Hosseinzade, Hadi; Feidt, Michel

    2016-01-01

    Highlights: • Based on finite speed method and direct method, the optimal performance is investigated. • The effects of major parameters on the optimal performance are investigated. • The accuracy of the results was compared with previous works. - Abstract: Popular thermodynamic analyses including finite time thermodynamic analysis was lately developed based upon external irreversibilities while internal irreversibilities such as friction, pressure drop and entropy generation were not considered. The aforementioned disadvantage reduces the reliability of the finite time thermodynamic analysis in the design of an accurate Stirling engine model. Consequently, the finite time thermodynamic analysis could not sufficiently satisfy researchers for implementing in design and optimization issues. In this study, finite speed thermodynamic analysis was employed instead of finite time thermodynamic analysis for studying Stirling heat engine. The finite speed thermodynamic analysis approach is based on the first law of thermodynamics for a closed system with finite speed and the direct method. The effects of heat source temperature, regenerating effectiveness, volumetric ratio, piston stroke as well as rotational speed are included in the analysis. Moreover, maximum output power in optimal rotational speed was calculated while pressure losses in the Stirling engine were systematically considered. The result reveals the accuracy and the reliability of the finite speed thermodynamic method in thermodynamic analysis of Stirling heat engine. The outcomes can help researchers in the design of an appropriate and efficient Stirling engine.

  4. An investigation of heat recovery of submarine diesel engines for combined cooling, heating and power systems

    International Nuclear Information System (INIS)

    Daghigh, Roonak; Shafieian, Abdellah

    2016-01-01

    Highlights: • The power output of the cycle is about 53 kW in the mass flow rate of 0.6 kg/s. • The output cooling water temperature of evaporator is 3.64 °C. • The absorption chiller has a coefficient of performance equal to 0.94. - Abstract: High temperature and mass flow rate of the exhaust gases of submarine diesel engines provide an appropriate potential for their thermal recovery. The current study introduces a combined cooling, heating and power system for thermal recovery of submarine diesel engines. The cooling system is composed of a mixed effect absorption chiller with two high and low pressure generators. The exhaust of the diesel engine is used in the high pressure generator, and the low pressure generator was divided into two parts. The required heat for the first and second compartments is supplied by the cooling water of the engine and condensation of the vapor generated in the high pressure generator, respectively. The power generation system is a Rankine cycle with an organic working fluid, which is considered a normal thermal system to supply hot water. The whole system is encoded based on mass stability, condensation and energy equations. The obtained findings showed that the maximum heat recovery for the power cycle occurs in exhaust gas mass ratio of 0.23–0.29 and working fluid mass flow rate of 0.45–0.57 kg/s. Further, for each specific mass ratio of exhaust gas, only a certain range of working fluid mass flow rate is used. In the refrigerant mass flow rate of 0.6 kg/s and exhaust gas mass ratio of 0.27, the power output of the cycle is 53 kW, which can also be achieved by simultaneous increase of refrigerant mass flow rate and exhaust gas mass ratio in a certain range of higher powers. In the next section, the overall distribution diagram of output water temperature of the thermal system is obtained according to the exhaust gas mass ratio in various mass flow rates, which can increase the potential of designing and controlling the

  5. Simulating conditions for combined heat and power in the Swedish district heating sector

    International Nuclear Information System (INIS)

    Knutsson, David

    2005-01-01

    The most important issues in the European energy sector today are how to increase competitiveness on the energy markets, reduce both CO2 emissions and dependence on imported fuels. These issues are also important aspects of Swedish energy policy. In Sweden, the district heating (DH) sector has commonly been used to achieve Swedish energy policy goals. However, the ongoing integration and deregulation of the energy markets in Europe now means that the Swedish DH sector can also play an important role in achieving international targets. This thesis investigates the extent to which the Swedish DH sector can contribute to compliance with current energy policy targets, both international and Swedish. The study consisted of simulations of the Swedish DH sector response to various policy instruments in a model that takes the local features of virtually all Swedish DH systems into account. The findings show, for example, that there is great potential for combined heat and power (CHP) generation in the Swedish DH sector. By exporting this CHP electricity to other European countries with less effective and fossil dependent power generation plants, the CO2 emissions from the European energy sector could be substantially reduced. This would also result in increased security of supply and competitiveness in the EU, since fuel use would be more effective. In Sweden, increased CHP generation would also be a way of maintaining an effective national security of supply of power

  6. ASSESSMENT OF COMBINED HEAT AND POWER SYSTEM"PREMIUM POWER" APPLICATIONS IN CALIFORNIA

    Energy Technology Data Exchange (ETDEWEB)

    Norwood, Zack; Lipman, Timothy; Stadler, Michael; Marnay, Chris

    2010-06-01

    The effectiveness of combined heat and power (CHP) systems for power interruption intolerant,"premium power," facilities is the focus of this study. Through three real-world case studies and economic cost minimization modeling, the economic and environmental performance of"premium power" CHP is analyzed. The results of the analysis for a brewery, data center, and hospital lead to some interesting conclusions about CHP limited to the specific CHP technologies installed at those sites. Firstly, facilities with high heating loads prove to be the most appropriate for CHP installations from a purely economic standpoint. Secondly, waste heat driven thermal cooling systems are only economically attractive if the technology for these chillers can increase above the current best system efficiency. Thirdly, if the reliability of CHP systems proves to be as high as diesel generators they could replace these generators at little or no additional cost if the thermal to electric (relative) load of those facilities was already high enough to economically justify a CHP system. Lastly, in terms of greenhouse gas emissions, the modeled CHP systems provide some degree of decreased emissions, estimated at approximately 10percent for the hospital, the application with the highest relative thermal load in this case

  7. Wind power integration with heat pumps, heat storages, and electric vehicles – Energy systems analysis and modelling

    DEFF Research Database (Denmark)

    Hedegaard, Karsten

    The fluctuating and only partly predictable nature of wind challenges an effective integration of large wind power penetrations. This PhD thesis investigates to which extent heat pumps, heat storages, and electric vehicles can support the integration of wind power. Considering the gaps in existing...... in an energy system context. Energy systems analyses reveal that the heat pumps can even without flexible operation contribute significantly to facilitating larger wind power investments and reducing system costs, fuel consumption, and CO2 emissions. When equipping the heat pumps with heat storages, only...... moderate additional benefits are achieved. Hereof, the main benefit is that the need for investing in peak/reserve capacities can be reduced through peak load shaving. It is more important to ensure flexible operation of electric vehicles than of individual heat pumps, due to differences in the load...

  8. Thermodynamic analysis of a directly heated oxyfuel supercritical power system

    International Nuclear Information System (INIS)

    Chowdhury, A.S.M. Arifur; Bugarin, Luz; Badhan, Antara; Choudhuri, Ahsan; Love, Norman

    2016-01-01

    Highlights: • A thermodynamic analysis of a supercritical power cycle is presented. • The supercritical power cycle is modeled using ASPEN HYSYS®. • A liquid methane and oxygen feed system is more efficient than a gaseous system. • CO_2 recirculated in gas form is 10.6% more efficient than when in liquid form. • Commercially available technologies permit liquid feed system delivery. - Abstract: Directly heated supercritical oxy-fuel gas turbines have potential to provide a higher thermal efficiency and lower pollutant emissions compared to current gas turbine systems. Motivated by the advantages of an oxyfuel-based directly heated supercritical power system, this paper presents an analysis of different operating conditions using ASPEN HYSYS®. This study first investigates the efficiency of gaseous or liquid methane and oxygen feed systems. T-s and P-v diagrams are generated and compared to each other to determine which is more efficient. The analysis revealed that the entropy generated during the combustion process for a liquid feed system is approximately three times higher than when methane and oxygen are compressed in gaseous form and delivered to the combustor and burned. To mitigate the high temperatures (3300 K) of the methane and oxygen combustion reaction, carbon dioxide is recirculated. For this portion of the system, the use of gaseous and liquid carbon dioxide recirculation loops and their corresponding efficiencies are determined. The investigation shows that the system yielded a higher net efficiency of 55.1% when gaseous carbon dioxide is recirculated as a diluent with liquid methane and oxygen delivery to the combustor.

  9. Biomass Supply Planning for Combined Heat and Power Plants using Stochastic Programming

    DEFF Research Database (Denmark)

    Guericke, Daniela; Blanco, Ignacio; Morales González, Juan Miguel

    method using stochastic optimization to support the biomass supply planning for combined heat and power plants. Our two-phase approach combines mid-term decisions about biomass supply contracts with the short-term decisions regarding the optimal market participation of the producer to ensure......During the last years, the consumption of biomass to produce power and heat has increased due to the new carbon neutral policies. Nowadays, many district heating systems operate their combined heat and power (CHP) plants using different types of biomass instead of fossil fuel, especially to produce......, and heat demand and electricity prices vary drastically during the planning period. Furthermore, the optimal operation of combined heat and power plants has to consider the existing synergies between the power and heating systems while always fulfilling the heat demand of the system. We propose a solution...

  10. New Configurations of Micro Plate-Fin Heat Sink to Reduce Coolant Pumping Power

    DEFF Research Database (Denmark)

    Kolaei, Alireza Rezania; Rosendahl, Lasse

    2012-01-01

    the optimum heat sink configuration. The particular focus of this study is to reduce the coolant mass flow rate by considering the thermal resistances of the heat sinks and, thereby, to reduce the coolant pumping power in the system. The threedimensional governing equations for the fluid flow and the heat......The thermal resistance of heat exchangers has a strong influence on the electric power produced by a thermoelectric generator (TEG). In this work, a real TEG device is applied to three configurations of micro plate-fin heat sink. The distance between certain microchannels is varied to find...... heat sink configurations reduces the coolant pumping power in the system....

  11. THE DIAGNOSIS TECHNIQUE OF ABNORMAL HEATING OF POWER CAPACITORS

    Directory of Open Access Journals (Sweden)

    D. I. Zalizny

    2016-01-01

    Full Text Available The existing system of protection and diagnostics are not able to detect abnormal heating of the power capacitors caused by its internal malfunction formation. The paper contains a proposal of a technique that enables to detect such heat at its early study. This technique consists of a hardware and an algorithms. The hardware consists of a microprocessor-based instrument developed by the author, of measuring transformers of current and of temperature sensors. This equipment must be connected to the condenser unit with a rated voltage of 380 V. In operation, the device performs continuous measurement of the surface temperature of the casing of each condenser, the temperature of the external environment, voltage and current from the power source. The measured values are used in the mathematical model of thermal processes that enables to calculate the temperature of the hottest point of each capacitor in real-time. Then the calculation of the intrinsic difference ΔΘ1° between the average temperature values of the dielectric and the base average value of this temperatures during the second day from the start of the measurements. If the Dq1 value exceeds the value of the absolute error of simulation, diagnostic signals of abnormal levels of heating, viz. low, medium, high and very high, are generated. It is also necessary to calculate the rate of change of ΔΘ1° and to consider the values obtained in the formation of hazard levels. For the low level and the average level of hazard the operation of diagnostic system with a visual signal is recommended, while for the high level of hazard it is recommended to use both visual and sound signals, and for the very high hazard level the capacitor ought to be turned off from the source. The algorithms have been developed heuristically. The final formation of the algorithms is possible only after the long-term operation of the proposed diagnosis system on real objects. The implementation of the

  12. Design for micro-combined cooling, heating and power systems stirling engines and renewable power systems

    CERN Document Server

    2015-01-01

    ‘Design for Micro-Combined Cooling, Heating & Power Systems’ provides a manual for the technical and structural design of systems for supplying decentralised energy in residential buildings. It presents the micro-combined cooling, heating & power systems Stirling engines & renewable energy sources (mCCHP-SE-RES) systems in an accessible manner both for the public at large, and for professionals who conceive, design or commercialise such systems or their components.  The high performance levels of these systems are demonstrated within the final chapter by the results of an experiment in which a house is equipped with a mCCHP-SE-RES system. The reader is also familiarized with the conceptual, technical and legal aspects of modern domestic energy systems; the components that constitute these systems; and advanced algorithms for achieving the structural and technical design of such systems. In residential buildings, satisfying demands of durable development has gradually evolved from necessity to...

  13. Influence of individual heat pumps on wind power integration – Energy system investments and operation

    International Nuclear Information System (INIS)

    Hedegaard, Karsten; Münster, Marie

    2013-01-01

    Highlights: • Individual heat pumps can significantly support the integration of wind power. • The heat pumps significantly reduce fuel consumption, CO 2 emissions, and costs. • Heat storages for the heat pumps can provide only moderate system benefits. • Main benefit of flexible heat pump operation is a lower peak/reserve capacity need. • Socio-economic feasibility only identified for some heat storages to some extent. - Abstract: Individual heat pumps are expected to constitute a significant electricity demand in future energy systems. This demand becomes flexible if investing in complementing heat storage capabilities. In this study, we analyse how the heat pumps can influence the integration of wind power by applying an energy system model that optimises both investments and operation, and covers various heat storage options. The Danish energy system by 2030 with around 50–60% wind power is used as a case study. Results show that the heat pumps, even without flexible operation, can contribute significantly to facilitating larger wind power investments and reducing system costs, fuel consumption, and CO 2 emissions. Investments in heat storages can provide only moderate system benefits in these respects. The main benefit of the flexible heat pump operation is a reduced need for peak/reserve capacity, which is also crucial for the feasibility of the heat storages. Socio-economic feasibility is identified for control equipment enabling intelligent heat storage in the building structure and in existing hot water tanks. In contrast, investments in new heat accumulation tanks are not found competitive

  14. Space chamber experiments of ohmic heating by high power microwave from the solar power satellite

    Energy Technology Data Exchange (ETDEWEB)

    Kaya, N.; Matsumoto, H.

    1981-12-01

    It is quantitatively predicted that a high power microwave from the Solar Power Satellite (SPS) nonlinearly interacts with the ionospheric plasma. The possible nonlinear interactions are ohmic heating, self-focusing and parametric instabilities. A rocket experiment called MINIX (Microwave-Ionosphere Nonlinear Interaction Experiment) has been attempted to examine these effects, but is note reported here. In parallel to the rocket experiment, a laboratory experiment in a space plasma simulation chamber has been carried out in order to examine ohmic heating in detail and to develop a system of the rocket experiment. Interesting results were observed and these results were utilized to revise the system of the rocket experiments. A significant microwave heating of plasma up to 150% temperature increase was observed with little electron density decrease. It was shown that the temperature increase is not due to the RF breakdown but to the ohmic heating in the simulated ionospheric plasma. These microwave effects have to be taken into account in the SPS Project in the future.

  15. Flue gas recovery system for natural gas combined heat and power plant with distributed peak-shaving heat pumps

    International Nuclear Information System (INIS)

    Zhao, Xiling; Fu, Lin; Wang, Xiaoyin; Sun, Tao; Wang, Jingyi; Zhang, Shigang

    2017-01-01

    Highlights: • A flue gas recovery system with distributed peak-shaving heat pumps is proposed. • The system can improve network transmission and distribution capacity. • The system is advantageous in energy saving, emission reduction and economic benefits. - Abstract: District heating systems use distributed heat pump peak-shaving technology to adjust heat in secondary networks of substations. This technology simultaneously adjusts the heat of the secondary network and reduces the return-water temperature of the primary network by using the heat pump principle. When optimized, low temperature return-water is able to recycle more waste heat, thereby further improving the heating efficiency of the system. This paper introduces a flue gas recovery system for a natural gas combined heat and power plant with distributed peak-shaving heat pumps. A pilot system comprising a set of two 9F gas-steam combined cycle-back pressure heating units was used to analyse the system configuration and key parameters. The proposed system improved the network transmission and distribution capacity, increased heating capacity, and reduced heating energy consumption without compromising heating safety issues. As such, the proposed system is advantageous in terms of energy saving, emission reduction, and economic benefits.

  16. Electric heating guidelines: power smart home; 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    Guidelines, for use by B. C. Hydro, were established for proper planning and design of an electric heating system for residential buildings. The guidebook is divided into five sections: (1) comfort and electric heating systems, (2) contractors` guide to heat loss calculation, (3) imperial heat loss factors, (4) metric heat loss factors, and (5) installation guidelines for electric heating systems. Individual topics discussed include heat loss and the human body, heating systems and comfort, heat loss design, air leakage, and soil conductivity factors. Design considerations and equipment standards were described for the following electric heating systems: electric resistance baseboard systems, forced flow unitary heaters, electric radiant cable in-floor systems, radiant ceiling systems, forced warm air heating systems, furnaces, and heat pumps. 68 tabs., 29 figs.

  17. Analysis of a novel solar energy-powered Rankine cycle for combined power and heat generation using supercritical carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X.R.; Yamaguchi, H.; Uneno, D. [Department of Mechanical Engineering, Doshisha University, Kyoto 630-0321 (Japan); Fujima, K. [Mayekawa MFG Co., Ltd., 2000 Tatsuzawa Moriya-city, Ibaraki-Pref. 302-0118 (Japan); Enomoto, M. [Showa Denko K. K., 1-480, Inuzuka, Oyama-city, Tochigi 323-8679 (Japan); Sawada, N. [Showa Tansan Co., Ltd., 7-1, Ogimachi, Kawasaki-Ku, Kawasaki-city, Kanagawa 210-0867 (Japan)

    2006-10-15

    Theoretical analysis of a solar energy-powered Rankine thermodynamic cycle utilizing an innovative new concept, which uses supercritical carbon dioxide as a working fluid, is presented. In this system, a truly 'natural' working fluid, carbon dioxide, is utilized to generate firstly electricity power and secondly high-grade heat power and low-grade heat power. The uniqueness of the system is in the way in which both solar energy and carbon dioxide, available in abundant quantities in all parts of the world, are simultaneously used to build up a thermodynamic cycle and has the potential to reduce energy shortage and greatly reduce carbon dioxide emissions and global warming, offering environmental and personal safety simultaneously. The system consists of an evacuated solar collector system, a power-generating turbine, a high-grade heat recovery system, a low-grade heat recovery system and a feed pump. The performances of this CO{sub 2}-based Rankine cycle were theoretically investigated and the effects of various design conditions, namely, solar radiation, solar collector area and CO{sub 2} flow rate, were studied. Numerical simulations show that the proposed system may have electricity power efficiency and heat power efficiency as high as 11.4% and 36.2%, respectively. It is also found that the cycle performances strongly depend on climate conditions. Also the electricity power and heat power outputs increase with the collector area and CO{sub 2} flow rate. The estimated COP{sub power} and COP{sub heat} increase with the CO{sub 2} flow rate, but decrease with the collector area. The CO{sub 2}-based cycle can be optimized to provide maximum power, maximum heat recovery or a combination of both. The results suggest the potential of this new concept for applications to electricity power and heat power generation. (author)

  18. After heat distribution of a mobile nuclear power plant

    Science.gov (United States)

    Parker, W. G.; Vanbibber, L. E.; Tang, Y. S.

    1971-01-01

    A computer program was developed to analyze the transient afterheat temperature and pressure response of a mobile gas-cooled reactor power plant following impact. The program considers (in addition to the standard modes of heat transfer) fission product decay and transport, metal-water reactions, core and shield melting and displacement, and pressure and containment vessel stress response. Analyses were performed for eight cases (both deformed and undeformed models) to verify operability of the program options. The results indicated that for a 350 psi (241 n/sq cm) initial internal pressure, the containment vessel can survive over 100,000 seconds following impact before creep rupture occurs. Recommendations were developed as to directions for redesign to extend containment vessel life.

  19. Farm effluent plant produces gas for domestic heat and power

    Energy Technology Data Exchange (ETDEWEB)

    1963-01-01

    A plant for treating farm waste waters, developed by Wright Rain Ltd. and based on a prototype plant invented by J. Fry which has been in continuous use for 5 years on a pig farm at Rietvlei, Johannesburg, is described. Manure is pumped into one end of the digestion tank about one-third of the way up the tank, and anaerobic decomposition occurs at a controlled temperature (optimum 35/sup 0/C); the gas rises to the top and is collected in gas holders to be utilized for domestic heat and power, while an outlet near the bottom of the tank allows decomposed matter to be drawn off for spreading. Results with pig manure suggest that a digestion tank should be planned for a 60-day cycle. Cow and pig manure can be digested without difficulty, but it would be necessary to add water to chicken manure for successful digestion.

  20. A comparison of combined heat and power feasibility models

    Energy Technology Data Exchange (ETDEWEB)

    Hinojosa, L.R.; Day, A.R.; Maidment, G.G. [Department of Engineering Systems, Faculty of Engineering, Science and the Built Environment, London South Bank University, 103 Borough Road, London SE1 0AA (United Kingdom); Dunham, C.; Kirk, P. [SEA/RENUE, 42 Braganza Street, London SE17 3RJ (United Kingdom)

    2007-09-15

    Carrying out feasibility studies for combined heat and power (CHP) in buildings systems is one of the most important steps in the decision-making process. This paper compares the features of different software packages available in the market and some custom-built models. It also discusses the advantages and disadvantages of building one's own application. The number of variables that need to be considered will depend on the level of accuracy and flexibility sought. Software packages are a good start, but they tend to be either overly simple or extremely complicated, and sometimes not very flexible. On the other hand, building custom-built generic models that include different technologies, unit sizes, control modes, market restrictions and benefits, can be a complex and laborious process, but will be more transparent to the user. (author)

  1. Grate-firing of biomass for heat and power production

    DEFF Research Database (Denmark)

    Yin, Chungen; Rosendahl, Lasse; Kær, Søren Knudsen

    2008-01-01

    bed on the grate, and the advanced secondary air supply (a real breakthrough in this technology) are highlighted for grate-firing systems. Amongst all the issues or problems associated with grate-fired boilers burning biomass, primary pollutant formation and control, deposition formation and corrosion......As a renewable and environmentally friendly energy source, biomass (i.e., any organic non-fossil fuel) and its utilization are gaining an increasingly important role worldwide Grate-firing is one of the main competing technologies in biomass combustion for heat and power production, because it can...... combustion mechanism, the recent breakthrough in the technology, the most pressing issues, the current research and development activities, and the critical future problems to be resolved. The grate assembly (the most characteristic element in grate-fired boilers), the key combustion mechanism in the fuel...

  2. Application of combined heat and power in Malaysia Industrial Sector

    International Nuclear Information System (INIS)

    Zaredah Hashim; Faridah Mohd Taha

    2010-01-01

    Malaysia is still working on continuing its economic growth especially in the industrial sector in order to achieve vision 2020. The rapid industrialization process has caused increment in the energy demand, which simultaneously increases carbon dioxide (CO 2 ) emissions. Energy efficient technologies are strongly needed for reducing the energy requirement and to avoid the depleting of energy resources. This project focused on the application of integrated resource planning (IRP) in industrial sector using Combined Heat and Power (CHP), as a strategy for Demand Side Management (DSM). This approach is another way for meeting near and future energy requirement in Malaysia's industrial sector. Two scenarios which are Business As Usual (BAU) and CHP were developed using End Use Model EUM), to forecast the energy demand and CO 2 emission in Malaysia's industries. The effectiveness of the proposed method is then simulated using Long Range Energy Alternative Planning System (LEAP) software and Comparative Model for Projects of Engineering Economics and Energy Environmental Development (COMPEED) analysis. Evaluations were based on the potential of energy saving and CO 2 reduction. Scope of research was limited to pulp and paper industrial sub sector. The research data were extracted from Energy Audit Reports conducted by Malaysia Energy Center (PTM). An engineering calculation was demonstrated. Two designs of CHP applications for the pulp and paper industrial sector are according to heating and electricity sizing. It was found that the most energy efficient and CO 2 reduction for Malaysia's industrial sector is the CHP based on heating requirement. The method was found to be able of save fuel and GHG emission compared to the reference case. (author)

  3. Integrating wind power using intelligent electric water heating

    International Nuclear Information System (INIS)

    Fitzgerald, Niall; Foley, Aoife M.; McKeogh, Eamon

    2012-01-01

    Dwindling fossil fuel resources and pressures to reduce greenhouse gas emissions will result in a more diverse range of generation portfolios for future electricity systems. Irrespective of the portfolio mix the overarching requirement for all electricity suppliers and system operators is to instantaneously meet demand, to operate to standards and reduce greenhouse gas emissions. Therefore all electricity market participants will ultimately need to use a variety of tools to balance the power system. Thus the role of demand side management with energy storage will be paramount to integrate future diverse generation portfolios. Electric water heating has been studied previously, particularly at the domestic level to provide load control, peak shave and to benefit end-users financially with lower bills, particularly in vertically integrated monopolies. In this paper a number of continuous direct load control demand response based electric water heating algorithms are modelled to test the effectiveness of wholesale electricity market signals to study the system benefits. The results are compared and contrasted to determine which control algorithm showed the best potential for energy savings, system marginal price savings and wind integration.

  4. Manufacture of power station heat exchangers using modern production technology

    International Nuclear Information System (INIS)

    Genzlinger, W.; Hoffmann, J.; Ohlhaeuser, K.

    1986-01-01

    Heat exchangers of high quality and operational safety can only be fabricated economically if fabrication is as 'simple' as possible and can be controlled and if, through value analysis, the work flows can be mechanized and automated and the following requirements are met: use of materials that are easy to work with for the application considered, choice of product designs and wall thicknesses that offer favourable conditions for processing and non-destructive testing, placing of seams in such a way that good accessibility for welding and minimum residual welding stresses are assured, minimizing the number of welding seams, use of automatic welding machines for submerged-arc welding and electronically controlled sources of welding current - semi-automatic equipment for spatter-free interfaces (pulse technique), electronically controlled equipment for welding in rollers and pipes and CNC-controlled machining centres for drilling pipe galleries (deep-hole drilling) and baffle plates and for machining the sealing elements after welding. Continuous inspections in each phase of fabrication assures that heat exchangers are made which fully meet the requirements of nuclear power station operators. (orig.)

  5. Optimization of Combine Heat and Power Plants in the Russian Wholesale Power Market Conditions

    Directory of Open Access Journals (Sweden)

    I. A. Chuchueva

    2015-01-01

    Full Text Available The paper concerns the relevant problem to optimize the combine heat and power (CHP plants in the Russian wholesale power market conditions. Since 1975 the CHP plants specialists faced the problem of fuel rate or fuel cost reduction while ensuring the fixed level of heat and power production. The optimality criterion was the fuel rate or fuel cost which has to be minimized. Produced heat and power was paid by known tariff. Since the power market started in 2006 the power payment scheme has essentially changed: produced power is paid by market price. In such condition a new optimality criterion the paper offers is a profit which has to be maximized for the given time horizon. Depending on the optimization horizon the paper suggests four types of the problem urgency, namely: long-term, mid-term, short-term, and operative optimization. It clearly shows that the previous problem of fuel cost minimization is a special case of profit maximization problem. To bring the problem to the mixed-integer linear programming problem a new linear characteristic curves of steam and gas turbine are introduced. Error of linearization is 0.6%. The formal statement of the problem of short-term CHP plants optimization in the market conditions is offered. The problem was solved with IRM software (OpenLinkInternational for seven power plants of JSC “Quadra”: Dyagilevskaya CHP, Kurskaya CHP-1, Lipetskaya CHP-2, Orlovskaya CHP, Kurskaya CHP NWR, Tambovskaya CHP, and Smolenskaya CHP-2.The conducted computational experiment showed that a potential profit is between 1.7% and 4.7% of the fuel cost of different CHP plants and depends on the power plant operation conditions. The potential profit value is 2–3 times higher than analogous estimations, which were obtained solving fuel cost minimization problem. The perspectives of the work are formalization of mid-term and long-term CHP plants optimization problem and development of domestic software for the new problem

  6. Application of industrial wood residues for combined heat and power production

    International Nuclear Information System (INIS)

    Majchrzycka, A.

    2015-01-01

    The paper discusses combined production of heat and power (CHP) from industrial wood residues. The system will be powered by wood residues generated during manufacturing process of wooden floor panels. Based on power and heat demands of the plant and wood residues potential, the CHP system was selected. Preliminary analysis of biomass conversion in CHP system and environmental impact was performed.

  7. Application of biogas for combined heat and power production in the rural region

    International Nuclear Information System (INIS)

    Kozak, T.; Majchrzycka, A.

    2009-01-01

    The paper discusses combined production of heat and power (CHP) from biogas in a small-scale power plant placed in the rural region. Based on power and heat demands of the rural region and biomass supply, the CHP system was selected. Keywords: biogas, cogeneration

  8. 78 FR 55117 - Ultimate Heat Sink for Nuclear Power Plants; Draft Regulatory Guide

    Science.gov (United States)

    2013-09-09

    ... NUCLEAR REGULATORY COMMISSION [NRC-2013-0203] Ultimate Heat Sink for Nuclear Power Plants; Draft... (DG), DG-1275, ``Ultimate Heat Sink for Nuclear Power Plants.'' This regulatory guide (RG) describes methods and procedures acceptable to the NRC staff that nuclear power plant facility licensees and...

  9. Possible directions for using bran in heat-power engineering

    Directory of Open Access Journals (Sweden)

    Gaydabrus Maria

    2017-01-01

    Full Text Available In connection with the necessity of providing of ecofriendlyness of energy the researches sent to the increase of stake of biomass in fuel and energy balance are actual direction of science and technique. The aim of work is put the study of heating engineering properties of bran and research of possibility of briquetting as it applies to the power use in the stratified fire-box devices. Research methods included standard methodologies of ISO and physical experiment. It is shown as a result of research that bran on the warmth of combustion is comparable with brown coals, but has a less ash-content considerably. However shallow factious composition of bran and caking in the process of ashing will result in high operating costs at their incineration in a natural kind. The variant of the power use of bran is considered as the preforms got the thermal pressing, and the optimal temperature of pressing, equal 150°C. On the example of pressing of shell of cedar nuts possibility of the use of bran is shown as connective, is set here.

  10. Feasibility study for Tashkent Heat and Power Plant Modernizing Project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    An investigational study was carried out of the project for energy conservation and greenhouse effect gas emission reduction by introducing the newest and most powerful gas turbine cogeneration facilities to the Tashkent cogeneration plant in Uzbekistan. At the Tashkent cogeneration plant, each of the facilities is being superannuated, which leads to lowering of operational reliability and increase in cost of repairs. In the project, studied was the introduction of the newest and most powerful gas turbine cogeneration facilities with heat output of 100 Gcal/h equivalent to that of one can of the existing hot water boiler and with generated output of 80MW. As a result of the study, obtained were the energy conservation amount of 83.9 ktoe/y and the greenhouse effect gas reduction amount of 179.7 kt-CO2/y. The initial investment amount was 10.003 billion yen. Expenses vs. effects were 8.39 toe/y-million yen in energy conservation amount and 18.0 t-CO2/y-million yen in greenhouse effect gas reduction amount. In the study of profitability, the internal earning rate was 9.24% after tax, the return yield of capital was 41.26%, and the period of ROI was 16.9 years. (NEDO)

  11. Comparing costs of power and heat production by prospective and present sources

    International Nuclear Information System (INIS)

    Novak, S.

    1979-01-01

    Capital and running costs are compared of power and heat production from different sources. The lowest capital costs were found for coal-fired power plants followed by light water reactor power plants. The capital costs of other types of power plants, such as wind, geothermal, solar, thermonuclear power plants are significantly higher. The estimated specific cost for electric power production in 1985 for a nuclear power plant is lower than for a fossil-fuel power plant. It is estimated that in 1985 coal will be the cheapest heat source. (Ha)

  12. Geothermal energy: clean power from the Earth's heat

    Science.gov (United States)

    Duffield, Wendell A.; Sass, John H.

    2003-01-01

    Societies in the 21st century require enormous amounts of energy to drive the machines of commerce and to sustain the lifestyles that many people have come to expect. Today, most of this energy is derived from oil, natural gas, and coal, supplemented by nuclear power. Local exceptions exist, but oil is by far the most common source of energy worldwide. Oil resources, however, are nonrenewable and concentrated in only a few places around the globe, creating uncertainty in long-term supply for many nations. At the time of the Middle East oil embargo of the 1970s, about a third of the United States oil supply was imported, mostly from that region. An interruption in the flow of this import disrupted nearly every citizen’s daily life, as well as the Nation’s economy. In response, the Federal Government launched substantial programs to accelerate development of means to increasingly harness “alternative energies”—primarily biomass, geothermal, solar, and wind. The new emphasis on simultaneously pursuing development of several sources of energy recognized the timeless wisdom found in the proverb of “not putting all eggs in one basket.” This book helps explain the role that geothermal resources can play in helping promote such diversity and in satisfying our Nation’s vast energy needs as we enter a new millennium. For centuries, people have enjoyed the benefits of geothermal energy available at hot springs, but it is only through technological advances made during the 20th century that we can tap this energy source in the subsurface and use it in a variety of ways, including the generation of electricity. Geothermal resources are simply exploitable concentrations of the Earth’s natural heat (thermal energy). The Earth is a bountiful source of thermal energy, continuously producing heat at depth, primarily by the decay of naturally occurring radioactive isotopes—principally of uranium, thorium, and potassium—that occur in small amounts in all rocks

  13. Satellite combined heat and power plants and their legal autonomy

    International Nuclear Information System (INIS)

    Loibl, Helmut

    2014-01-01

    Since the landmark decision by the German Court of Justice concerning the term ''plant'' in the context of biogas plants it should be clear beyond doubt that satellite combined heat and power plants (CHPs) are legally autonomous plants pursuant to Para. 3 No. 1 of the Renewable Energy Law (EEG). What has yet to be finally resolved are the conditions under which satellite CHPs are to be regarded as autonomous. This will be a question of distance on the one hand and of operation autonomy on the other. In the individual case both these factors will have to be assessed from the perspective of an average objective, informed citizen. To the extent that its heat and electricity are being utilised in a meaningful manner, the plant's autonomy will be beyond doubt, at least in operational terms. Regarding the remuneration to be paid for satellite CHPs the only case requiring special consideration is when a CHP falls under the EEG of 2012. In this case Para. 1 Section 1 Sentence 2 EEG provides that the remuneration for the CHP in question is to be calculated as if there was a single overall plant. To the extent that none of the CHPs fall under the EEG of 2012, the ruling remains that there is a separate entitlement to remuneration for each satellite CHP. This also holds in cases where satellite CHPs that were commissioned after 1 January 2012 are relocated. When a satellite CHP is replaced by a new one, the rate and duration of remuneration remain unchanged. However, when a new satellite CHP is added to an existing satellite CHP via a gas collector line it is to be treated according to the decisions of the Federal Court of Justice concerning biogas plant extensions: It falls under the law that applies to the existing CHP and has an entitlement to a new minimum remuneration period, albeit subject to the degression rate provided by the EEG version in question.

  14. Structural steels for power generating equipment and heat and chemical heat treatments

    International Nuclear Information System (INIS)

    Astaf'ev, A.A.

    1979-01-01

    Development of structural steels for power generating equipment and for reactor engineering, in particular, is elucidated. Noted is utilization of the 15Kh2NMFA steels for the WWER-1000 reactor vessels, the 10GN2MFA steels for steam generators, pressurizers, vessels of the automatic emergency shut down and safety system; the 00Kh12N3DL steel for cast pump vessels and main locking bars. The recommendations on heat treatment of big forgings, for instance, ensuring the necessary complex of mechanical properties are given. Diffusion chromizing with subsequent nitriding of austenitic steels which increase durability of the components in BN reactors more than 4 times, is practised on a large scale

  15. Wind-power turns up the heat - Minergie, heat pumps and wind; Windstrom heizt ein

    Energy Technology Data Exchange (ETDEWEB)

    Gutknecht, B.

    2003-07-01

    This short article discusses the advantages of using wind energy to provide lighting as well as power for the heat pumps often used in houses built to the Swiss Minergie low-energy consumption standard. The extra costs caused by purchase of wind-generated electrical energy instead of 'normal' electricity are, according to the author, low in comparison with other costs incurred by the inhabitants for such things as, for example, pocket money, internet connections and other amenities. A sample calculation for an average Minergie house is presented. The article is rounded off by a collection of facts on wind energy in general and its use in Switzerland in particular.

  16. New Configurations of Micro Plate-Fin Heat Sink to Reduce Coolant Pumping Power

    Science.gov (United States)

    Rezania, A.; Rosendahl, L. A.

    2012-06-01

    The thermal resistance of heat exchangers has a strong influence on the electric power produced by a thermoelectric generator (TEG). In this work, a real TEG device is applied to three configurations of micro plate-fin heat sink. The distance between certain microchannels is varied to find the optimum heat sink configuration. The particular focus of this study is to reduce the coolant mass flow rate by considering the thermal resistances of the heat sinks and, thereby, to reduce the coolant pumping power in the system. The three-dimensional governing equations for the fluid flow and the heat transfer are solved using the finite-volume method for a wide range of pressure drop laminar flows along the heat sink. The temperature and the mass flow rate distribution in the heat sink are discussed. The results, which are in good agreement with previous computational studies, show that using suggested heat sink configurations reduces the coolant pumping power in the system.

  17. Waste-Heat-to-Power Market in the U.S., Heat is Power Annual Meeting (Presentation) – August 15, 2012

    Science.gov (United States)

    This presentation provides information about the EPA CHP Partnership, including an overview of the Partnership's tools and resources, and policy support. The presentation also describes the potential of Waste Heat to Power (WHP) systems.

  18. Low temperature heat source for power generation: Exhaustive analysis of a carbon dioxide transcritical power cycle

    International Nuclear Information System (INIS)

    Velez, Fredy; Segovia, Jose; Chejne, Farid; Antolin, Gregorio; Quijano, Ana; Carmen Martin, M.

    2011-01-01

    The main results of a theoretical work on the use of a low temperature heat source for power generation through a carbon dioxide transcritical power cycle are reported in this paper. The procedure for analyzing the behaviour of the proposed cycle consisted in modifying the input pressure to the turbine from 66 bar, maintained constant each evaluated temperature (60 o C, 90 o C, 120 o C and 150 o C) until the net work was approximately zero. As a result, the maximum exergy efficiency was 50%, while the energy efficiencies obtained were 9.8%, 7.3%, 4.9% and 2.4% and the net specific work was 18.2 kJ/kg, 12.8 kJ/kg, 7.8 kJ/kg and 3.5 kJ/kg, respectively. Furthermore, the effect of the addition of an internal heat exchanger, which obviously supposed an increase in the efficiency, was analyzed. The analysis of the proposed system shows the viability of implementing this type of process as an energy alternative and/or strengthener of non-conventional energy sources in non-provided zones, or for increasing the energy efficiency in the industry. -- Highlights: → Energy and exergy analysis of a carbon dioxide transcritical power cycle is reported. → The effect of the inlet temperature to the turbine is evaluated. → Conditions of maximum efficiency and maximum net work are compared. → The inclusion of an IHX is also analysed.

  19. Heat losses in power boilers caused by thermal bridges

    Directory of Open Access Journals (Sweden)

    Kocot Monika

    2017-01-01

    Full Text Available In this article the analysis of heat losses caused by thermal bridges that occur in the steam boiler OP-140 is presented. Identification of these bridges were conducted with use of thermographic camera. Heat losses were evaluated based on methodology of VDI 4610 standard, but instead of its simplified equations, criterial equations based on Nusselt number were used. Obtained values of annual heat losses and heat flux density corresponding to the fully insulated boiler surfaces were compared to heat losses generated by thermal bridges located in the same areas. The emphasis is put on the role of industrial insulation in heat losses reduction.

  20. Designing a solar powered Stirling heat engine based on multiple criteria: Maximized thermal efficiency and power

    International Nuclear Information System (INIS)

    Ahmadi, Mohammad Hossein; Sayyaadi, Hoseyn; Dehghani, Saeed; Hosseinzade, Hadi

    2013-01-01

    Highlights: • Thermodynamic model of a solar-dish Stirling engine was presented. • Thermal efficiency and output power of the engine were simultaneously maximized. • A final optimal solution was selected using several decision-making methods. • An optimal solution with least deviation from the ideal design was obtained. • Optimal solutions showed high sensitivity against variation of system parameters. - Abstract: A solar-powered high temperature differential Stirling engine was considered for optimization using multiple criteria. A thermal model was developed so that the output power and thermal efficiency of the solar Stirling system with finite rate of heat transfer, regenerative heat loss, conductive thermal bridging loss, finite regeneration process time and imperfect performance of the dish collector could be obtained. The output power and overall thermal efficiency were considered for simultaneous maximization. Multi-objective evolutionary algorithms (MOEAs) based on the NSGA-II algorithm were employed while the solar absorber temperature and the highest and lowest temperatures of the working fluid were considered the decision variables. The Pareto optimal frontier was obtained and a final optimal solution was also selected using various decision-making methods including the fuzzy Bellman–Zadeh, LINMAP and TOPSIS. It was found that multi-objective optimization could yield results with a relatively low deviation from the ideal solution in comparison to the conventional single objective approach. Furthermore, it was shown that, if the weight of thermal efficiency as one of the objective functions is considered to be greater than weight of the power objective, lower absorber temperature and low temperature ratio should be considered in the design of the Stirling engine

  1. Techno-economic analysis of using corn stover to supply heat and power to a corn ethanol plant - Part 2: Cost of heat and power generation systems

    International Nuclear Information System (INIS)

    Mani, S.; Sokhansanj, S.; Tagore, S.; Turhollow, A.F.

    2010-01-01

    This paper presents a techno-economic analysis of corn stover fired process heating (PH) and the combined heat and power (CHP) generation systems for a typical corn ethanol plant (ethanol production capacity of 170 dam 3 ). Discounted cash flow method was used to estimate both the capital and operating costs of each system and compared with the existing natural gas fired heating system. Environmental impact assessment of using corn stover, coal and natural gas in the heat and/or power generation systems was also evaluated. Coal fired process heating (PH) system had the lowest annual operating cost due to the low fuel cost, but had the highest environmental and human toxicity impacts. The proposed combined heat and power (CHP) generation system required about 137 Gg of corn stover to generate 9.5 MW of electricity and 52.3 MW of process heat with an overall CHP efficiency of 83.3%. Stover fired CHP system would generate an annual savings of 3.6 M$ with an payback period of 6 y. Economics of the coal fired CHP system was very attractive compared to the stover fired CHP system due to lower fuel cost. But the greenhouse gas emissions per Mg of fuel for the coal fired CHP system was 32 times higher than that of stover fired CHP system. Corn stover fired heat and power generation system for a corn ethanol plant can improve the net energy balance and add environmental benefits to the corn to ethanol biorefinery.

  2. Break-through technologies. Power and/or heat generation; Genombrottstekniker. Kraft- vaermeproduktion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    This report gives a compilation of technologies for the future in producing electric power and heat. The focus is on the areas Cogeneration, Fuel cells, Wind power, Solar cells, Artificial photosynthesis, and Hydrogen. Refs, 9 figs, 5 tabs

  3. High Efficiency, High Temperature Foam Core Heat Exchanger for Fission Surface Power Systems, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Fission-based power systems with power levels of 30 to ≥100 kWe will be needed for planetary surface bases. Development of high temperature, high efficiency heat...

  4. Study on a heat recovery system for the thermal power plant utilizing air cooling island

    International Nuclear Information System (INIS)

    Sun, Jian; Fu, Lin; Sun, Fangtian; Zhang, Shigang

    2014-01-01

    A new heat recovery system for CHP (combined heat and power) systems named HRU (heat recovery unit) is presented, which could recover the low grade heat of exhausted steam from the turbine at the thermal power plant directly. Heat recovery of exhausted steam is often accomplished by recovering the heat of cooling water in current systems. Therefore, two processes of heat transfer is needed at least. However, exhausted steam could be condensed in the evaporator of HRU directly, which reduce one process of heat transfer. A special evaporator is designed condense the exhausted steam directly. Simulated results are compared to experiments, which could include the calculation of heat transfer coefficients of different parts of HRU. It is found that about 25Mw of exhausted steam is recovered by this system. HRU could be promising for conventional CHP systems, which could increase the total energy efficiency obviously and enlarge the heating capacity of a built CHP system. - Highlights: • A new heat recovery system for thermal power plant is presented. • A mathematical model including heat transfer coefficients calculation is given. • This heat recovery system is experimented at a thermal power plant. • Performances of this system under different working conditions are simulated

  5. Quantifying demand flexibility of power-to-heat and thermal energy storage in the control of building heating systems

    DEFF Research Database (Denmark)

    Finck, Christian; Li, Rongling; Kramer, Rick

    2018-01-01

    restricted by power-to-heat conversion such as heat pumps and thermal energy storage possibilities of a building. To quantify building demand flexibility, it is essential to capture the dynamic response of the building energy system with thermal energy storage. To identify the maximum flexibility a building......’s energy system can provide, optimal control is required. In this paper, optimal control serves to determine in detail demand flexibility of an office building equipped with heat pump, electric heater, and thermal energy storage tanks. The demand flexibility is quantified using different performance...... of TES and power-to-heat in any case of charging, discharging or idle mode. A simulation case study is performed showing that a water tank, a phase change material tank, and a thermochemical material tank integrated with building heating system can be designed to provide flexibility with optimal control....

  6. A Co-Powered Biomass and Concentrated Solar Power Rankine Cycle Concept for Small Size Combined Heat and Power Generation

    Directory of Open Access Journals (Sweden)

    Eileen Tortora

    2013-03-01

    Full Text Available The present work investigates the matching of an advanced small scale Combined Heat and Power (CHP Rankine cycle plant with end-user thermal and electric load. The power plant consists of a concentrated solar power field co-powered by a biomass furnace to produce steam in a Rankine cycle, with a CHP configuration. A hotel was selected as the end user due to its high thermal to electric consumption ratio. The power plant design and its operation were modelled and investigated by adopting transient simulations with an hourly distribution. The study of the load matching of the proposed renewable power technology and the final user has been carried out by comparing two different load tracking scenarios, i.e., the thermal and the electric demands. As a result, the power output follows fairly well the given load curves, supplying, on a selected winter day, about 50 GJ/d of thermal energy and the 6 GJ/d of electric energy, with reduced energy dumps when matching the load.

  7. Heat-pipe development for the SPAR space-power system

    International Nuclear Information System (INIS)

    Ranken, W.A.

    1981-01-01

    The SPAR space power system design is based on a high temperature fast spectrum nuclear reactor that furnishes heat to a thermoelectric conversion system to generate an electrical power output of 100 kW/sub (e)/. An important feature of this design is the use of alkali metal heat pipes to provide redundant, reliable, and low-loss heat transfer at high temperature. Three sets of heat pipes are used in the system. These include sodium/molybdenum heat pipes to transfer heat from the reactor core to the conversion system, potassium/niobium heat pipes to couple the conversion system to the radiator in a redundant manner, and potassium/titanium heat pipes to distribute rejected heat throughout the radiator surface. The designs of these units are discussed and fabrication methods and testing results are described. 12 figures

  8. Numerical simulation of flow field in shellside of heat exchanger in nuclear power plant

    International Nuclear Information System (INIS)

    Wang Xinliang; Qiu Jinrong; Gong Zili

    2010-01-01

    Heat exchanger is the important equipment of nuclear power plant. Numerical simulation can give the detail information inside the heat exchange, and has been an effective research method. The geometric structure of shell-and-tube heat exchanger is very complex and it is difficult to simulate the whole flow field presently. According to the structure characteristics of the heat exchanger, a periodic whole-section calculation model was presented. The numerical simulation of flow field in shellside of heat exchange of a nuclear power plant was done by using this model. The results of simulation show that heat transfer in the periodic section of the heat exchange is uniform, the heat transfer is enhanced by using baffles in heat exchange, and frictional resistance is primary from the effect of segmental baffles. (authors)

  9. A minimization procedure for estimating the power deposition and heat transport from the temperature response to auxiliary power modulation

    International Nuclear Information System (INIS)

    Eester, Dirk van

    2004-01-01

    A method commonly used for determining where externally launched power is absorbed inside a tokamak plasma is to examine the temperature response to modulation of the launched power. Strictly speaking, this response merely provides a first good guess of the actual power deposition rather than the deposition profile itself: not only local heat sources but also heat losses and heat wave propagation affect the temperature response at a given position. Making use of this, at first sight non-desirable, effect modulation becomes a useful tool for conducting transport studies. In this paper a minimization method based on a simple conduction-convection model is proposed for deducing the power deposition and transport characteristics from the experimentally measured (electron) energy density response to a modulation of the auxiliary heating power. An L-mode JET example illustrates the potential of the technique

  10. local alternative sources for cogeneration combined heat and power system

    Science.gov (United States)

    Agll, Abdulhakim Amer

    Global demand for energy continues to grow while countries around the globe race to reduce their reliance on fossil fuels and greenhouse gas emissions by implementing policy measures and advancing technology. Sustainability has become an important issue in transportation and infrastructure development projects. While several agencies are trying to incorporate a range of sustainability measures in their goals and missions, only a few planning agencies have been able to implement these policies and they are far from perfect. The low rate of success in implementing sustainable policies is primarily due to incomplete understanding of the system and the interaction between various elements of the system. The conventional planning efforts focuses mainly on performance measures pertaining to the system and its impact on the environment but seldom on the social and economic impacts. The objective of this study is to use clean and alternative energy can be produced from many sources, and even use existing materials for energy generation. One such pathway is using wastewater, animal and organic waste, or landfills to create biogas for energy production. There are three tasks for this study. In topic one evaluated the energy saving that produced from combined hydrogen, heat, and power and mitigate greenhouse gas emissions by using local sustainable energy at the Missouri S&T campus to reduce energy consumption and fossil fuel usage. Second topic aimed to estimate energy recovery and power generation from alternative energy source by using Rankin steam cycle from municipal solid waste at Benghazi-Libya. And the last task is in progress. The results for topics one and two have been presented.

  11. Stochastic analysis of residential micro combined heat and power system

    International Nuclear Information System (INIS)

    Karami, H.; Sanjari, M.J.; Gooi, H.B.; Gharehpetian, G.B.; Guerrero, J.M.

    2017-01-01

    Highlights: • Applying colonial competitive algorithm to the problem of optimal dispatching. • Economic modeling of the residential integrated energy system. • Investigating differences of stand-alone and system-connected modes of fuel cell operation. • Considering uncertainty on the electrical load. • The effects of battery capacity and its efficiency on the system is investigated. - Abstract: In this paper the combined heat and power functionality of a fuel-cell in a residential hybrid energy system, including a battery, is studied. The demand uncertainties are modeled by investigating the stochastic load behavior by applying Monte Carlo simulation. The colonial competitive algorithm is adopted to the hybrid energy system scheduling problem and different energy resources are optimally scheduled to have optimal operating cost of hybrid energy system. In order to show the effectiveness of the colonial competitive algorithm, the results are compared with the results of the harmony search algorithm. The optimized scheduling of different energy resources is listed in an efficient look-up table for all time intervals. The effects of time of use and the battery efficiency and its size are investigated on the operating cost of the hybrid energy system. The results of this paper are expected to be used effectively in a real hybrid energy system.

  12. High efficiency combined heat and power facilities - benefits and barriers

    International Nuclear Information System (INIS)

    Klein, M.

    2001-01-01

    There are important linkages between the economy, energy production, the environment and our health. Where thermal energy is needed, distributed Combined Heat and Power facilities, using gas turbines, reciprocating engines and future fuel cells can provide significant improvements to our long term mix of energy production. Local generation can also have benefits in security of energy supply and economic savings. This paper is intended to discuss the relevant air pollution and greenhouse gas emissions from modem CHP plants, the emission prevention and reduction methods available, and their operating experience and cost-effectiveness. Mention is made of recently constructed industrial and commercial plants, and institutional barriers to further development. Solutions described for these barriers include the need for more awareness of opportunities, improved access to the electricity grid, the proper design balance between thermal and electric for CHP systems rather than large combined cycles, improved corporate taxation incentives, and the assessment of all environmental and economic benefits when considering such cleaner sources in a restructured energy market. (author)

  13. Utilization of low-temperature heat sources for heat and power production

    DEFF Research Database (Denmark)

    Haglind, Fredrik; Elmegaard, Brian

    2014-01-01

    Low-temperature heat sources are available in many applications, ranging from waste heat from marine diesel engines, industries and refrigeration plants to biomass, geothermal and solar heat sources. There is a great potential for enhancing the utilization of these heat sources by novel...

  14. Influence of individual heat pumps on wind power integration – Energy system investments and operation

    DEFF Research Database (Denmark)

    Hedegaard, Karsten; Münster, Marie

    2013-01-01

    Individual heat pumps are expected to constitute a significant electricity demand in future energy systems. This demand becomes flexible if investing in complementing heat storage capabilities. In this study, we analyse how the heat pumps can influence the integration of wind power by applying...... an energy system model that optimises both investments and operation, and covers various heat storage options. The Danish energy system by 2030 with around 50–60% wind power is used as a case study. Results show that the heat pumps, even without flexible operation, can contribute significantly...... to facilitating larger wind power investments and reducing system costs, fuel consumption, and CO2 emissions. Investments in heat storages can provide only moderate system benefits in these respects. The main benefit of the flexible heat pump operation is a reduced need for peak/reserve capacity, which is also...

  15. Experimental and numerical study of latent heat thermal energy storage systems assisted by heat pipes for concentrated solar power application

    Science.gov (United States)

    Tiari, Saeed

    A desirable feature of concentrated solar power (CSP) with integrated thermal energy storage (TES) unit is to provide electricity in a dispatchable manner during cloud transient and non-daylight hours. Latent heat thermal energy storage (LHTES) offers many advantages such as higher energy storage density, wider range of operating temperature and nearly isothermal heat transfer relative to sensible heat thermal energy storage (SHTES), which is the current standard for trough and tower CSP systems. Despite the advantages mentioned above, LHTES systems performance is often limited by low thermal conductivity of commonly used, low cost phase change materials (PCMs). Research and development of passive heat transfer devices, such as heat pipes (HPs) to enhance the heat transfer in the PCM has received considerable attention. Due to its high effective thermal conductivity, heat pipe can transport large amounts of heat with relatively small temperature difference. The objective of this research is to study the charging and discharging processes of heat pipe-assisted LHTES systems using computational fluid dynamics (CFD) and experimental testing to develop a method for more efficient energy storage system design. The results revealed that the heat pipe network configurations and the quantities of heat pipes integrated in a thermal energy storage system have a profound effect on the thermal response of the system. The optimal placement of heat pipes in the system can significantly enhance the thermal performance. It was also found that the inclusion of natural convection heat transfer in the CFD simulation of the system is necessary to have a realistic prediction of a latent heat thermal storage system performance. In addition, the effects of geometrical features and quantity of fins attached to the HPs have been studied.

  16. Thermoelectric cooling of microelectronic circuits and waste heat electrical power generation in a desktop personal computer

    International Nuclear Information System (INIS)

    Gould, C.A.; Shammas, N.Y.A.; Grainger, S.; Taylor, I.

    2011-01-01

    Thermoelectric cooling and micro-power generation from waste heat within a standard desktop computer has been demonstrated. A thermoelectric test system has been designed and constructed, with typical test results presented for thermoelectric cooling and micro-power generation when the computer is executing a number of different applications. A thermoelectric module, operating as a heat pump, can lower the operating temperature of the computer's microprocessor and graphics processor to temperatures below ambient conditions. A small amount of electrical power, typically in the micro-watt or milli-watt range, can be generated by a thermoelectric module attached to the outside of the computer's standard heat sink assembly, when a secondary heat sink is attached to the other side of the thermoelectric module. Maximum electrical power can be generated by the thermoelectric module when a water cooled heat sink is used as the secondary heat sink, as this produces the greatest temperature difference between both sides of the module.

  17. THE MODEL FOR POWER EFFICIENCY ASSESSMENT OF CONDENSATION HEATING INSTALLATIONS

    Directory of Open Access Journals (Sweden)

    D. Kovalchuk

    2017-11-01

    Full Text Available The main part of heating systems and domestic hot water systems are based on the natural gas boilers. Forincreasing the overall performance of such heating system the condensation gas boilers was developed and are used. Howevereven such type of boilers don't use all energy which is released from a fuel combustion. The main factors influencing thelowering of overall performance of condensation gas boilers in case of operation in real conditions are considered. Thestructure of the developed mathematical model allowing estimating the overall performance of condensation gas boilers(CGB in the conditions of real operation is considered. Performace evaluation computer experiments of such CGB during aheating season for real weather conditions of two regions of Ukraine was made. Graphic dependences of temperatureconditions and heating system effectiveness change throughout a heating season are given. It was proved that normal CGBdoes not completely use all calorific value of fuel, thus, it isn't effective. It was also proved that the efficiency of such boilerssignificantly changes during a heating season depending on weather conditions and doesn't reach the greatest possible value.The possibility of increasing the efficiency of CGB due to hydraulic division of heating and condensation sections and use ofthe vapor-compression heat pump for deeper cooling of combustion gases and removing of the highest possible amount ofthermal energy from them are considered. The scheme of heat pump connection to the heating system with a convenient gasboiler and the separate condensation economizer allowing to cool combustion gases deeply below a dew point and to warm upthe return heat carrier before a boiler input is provided. The technological diagram of the year-round use of the heat pump forhot water heating after the end of heating season, without gas use is offered.

  18. Robust Management of Combined Heat and Power Systems via Linear Decision Rules

    DEFF Research Database (Denmark)

    Zugno, Marco; Morales González, Juan Miguel; Madsen, Henrik

    2014-01-01

    The heat and power outputs of Combined Heat and Power (CHP) units are jointly constrained. Hence, the optimal management of systems including CHP units is a multicommodity optimization problem. Problems of this type are stochastic, owing to the uncertainty inherent both in the demand for heat and...... linear decision rules to guarantee both tractability and a correct representation of the dynamic aspects of the problem. Numerical results from an illustrative example confirm the value of the proposed approach....

  19. Performances of nuclear power plants for combined production of electricity and hot water for district heating

    International Nuclear Information System (INIS)

    Bronzen, S.

    The possibilities for using nuclear power plants for combined production of heat and power seem to be very good in the future. With the chosen 600 MWsub (e) BWR plant a heat output up to 1200 MW can be arranged. An alternative, consisting of steam extractions from the low-pressure turbine, offers a flexible solution for heat and power generation. With this alternative the combined plant can use components from normal condensing nuclear power plants. The flexible extraction design also offers a real possibility for using the combined plant in electric peak generation. However, urban siting requires long distance heat transmission and the pipe design for this transmission is a major problem when planning and optimizing the whole nuclear combined heat and power plant. (author)

  20. An innovative ORC power plant layout for heat and power generation from medium- to low-temperature geothermal resources

    International Nuclear Information System (INIS)

    Fiaschi, Daniele; Lifshitz, Adi; Manfrida, Giampaolo; Tempesti, Duccio

    2014-01-01

    Highlights: • Explotation of medium temperature geothermal resource with ORC–CHP is investigated. • A new CHP configuration to provide higher temperature to thermal user is proposed. • Several organic fluids and wide range of heat demand are studied. • The system produces higher power (almost 55%) in comparison to typical layouts. • Optimal working fluids vary with the characteristics of the heat demand. - Abstract: Medium temperature (up to 170 °C), water dominated geothermal resources are the most widespread in the world. The binary geothermal-ORC power plants are the most suitable energy conversion systems for this kind of resource. Specifically, combined heat and power (CHP) systems have the potential to improve the efficiency in exploiting the geothermal resources by cascading the geothermal fluid heat carrier to successively lower temperature users, thus increasing first and second law efficiency of the entire power plant. However, geothermal CHPs usually extract heat from the geofluid either in parallel or in series to the ORC, and usually provide only low temperature heat, which is seldom suitable for industrial use. In this paper, a new CHP configuration, called Cross Parallel CHP, has been proposed and analyzed. It aims to provide higher temperature heat suitable for industrial use, allowing the exploitation of geothermal resources even in areas where district heating is not needed. The proposed CHP allows the reduction of the irreversibilities in the heat exchangers and the loss to the environment related to the re-injection of geofluid, thus producing higher electric power output while satisfying, at the same time, the heat demand of the thermal utility for a wide range of temperatures and mass flow rates (80–140 °C; 3–13 kg/s). Several organic fluids are investigated and the related optimizing working conditions are found by a built in procedure making use of genetic algorithms. The results show that the optimal working fluids and

  1. Participation of nuclear power plants in variable operation regimes under conditions of combined electric power and heat generation

    International Nuclear Information System (INIS)

    Rydzi, S.

    1988-01-01

    The incorporation of nuclear power units in the control of the output of an electric power system is affected by technical and economic factors as well as by the manner of heat take-off from the nuclear power unit for heating purposes. The effect was therefore studied of the technological solution of converting the heat output of WWER-440 units to operating parameters of turbines in nonrated regimes of operation. Some results of the study are graphically represented. An analysis was also made of limitations preventing WWER-440 units from supplying heat with regard to their incorporation in the electric power transmission system. The results show that using nuclear power units for district heating will in the future strictly determine the seasonal shut-down of nuclear units for fuel exchange and overhauls. This could interfere with the considered concept of the 1.5 year duty time of WWER-440 reactors. With regard to the economy of operation of the nuclear power system and reduced demands on weekend unloading it will be necessary to incorporate in the power system pumped-storage power plants with one-week pumped-storage systems. (Z.M.). 5 figs., 2 tabs., 6 refs

  2. Performance Analysis and Optimization of a Solar Powered Stirling Engine with Heat Transfer Considerations

    Directory of Open Access Journals (Sweden)

    Chia-En Ho

    2012-09-01

    Full Text Available This paper investigates the optimization of the performance of a solar powered Stirling engine based on finite-time thermodynamics. Heat transference in the heat exchangers between a concentrating solar collector and the Stirling engine is studied. The irreversibility of a Stirling engine is considered with the heat transfer following Newton's law. The power generated by a Stirling engine is used as an objective function for maximum power output design with the concentrating solar collector temperature and the engine thermal efficiency as the optimization parameters. The maximum output power of engine and its corresponding system parameters are determined using a genetic algorithm.

  3. The Sydvaerme project: District heating from the Barsebeck nuclear power plant

    International Nuclear Information System (INIS)

    Josefsson, L.

    1977-01-01

    The paper presents a summary report of a study on district heating from Barsebeck Nuclear Power Plant in Sweden, prepared cooperatively by the cities of Malmoe, Lund, Helsingborg, Landskrona and the electric power company Sydkraft. A future number 3 generating set at the Barsebeck nuclear power station could be designed for combined production of heat and electric power. The generating set could be completed after 1983, and could then supply about 65% of total district heating requirements. The first stage of the investigation includes a proposal for a technically feasible solution, sufficiently detailed to permit both technical and economic evaluation of the project. (author)

  4. Application of sorption heat pumps for increasing of new power sources efficiency

    Science.gov (United States)

    Vasiliev, L.; Filatova, O.; Tsitovich, A.

    2010-07-01

    In the 21st century the way to increase the efficiency of new sources of energy is directly related with extended exploration of renewable energy. This modern tendency ensures the fuel economy needs to be realized with nature protection. The increasing of new power sources efficiency (cogeneration, trigeneration systems, fuel cells, photovoltaic systems) can be performed by application of solid sorption heat pumps, regrigerators, heat and cold accumulators, heat transformers, natural gas and hydrogen storage systems and efficient heat exchangers.

  5. Anaerobic Digestion and Combined Heat and Power Study

    Energy Technology Data Exchange (ETDEWEB)

    Frank J. Hartz

    2011-12-30

    One of the underlying objectives of this study is to recover the untapped energy in wastewater biomass. Some national statistics worth considering include: (1) 5% of the electrical energy demand in the US is used to treat municipal wastewater; (2) This carbon rich wastewater is an untapped energy resource; (3) Only 10% of wastewater treatment plants (>5mgd) recover energy; (4) Wastewater treatment plants have the potential to produce > 575 MW of energy nationwide; and (5) Wastewater treatment plants have the potential to capture an additional 175 MW of energy from waste Fats, Oils and Grease. The WSSC conducted this study to determine the feasibility of utilizing anaerobic digestion and combined heat and power (AD/CHP) and/or biosolids gasification and drying facilities to produce and utilize renewable digester biogas. Digester gas is considered a renewable energy source and can be used in place of fossil fuels to reduce greenhouse gas emissions. The project focus includes: (1) Converting wastewater Biomass to Electricity; (2) Using innovative technologies to Maximize Energy Recovery; and (3) Enhancing the Environment by reducing nutrient load to waterways (Chesapeake Bay), Sanitary Sewer Overflows (by reducing FOG in sewers) and Greenhouse Gas Emissions. The study consisted of these four tasks: (1) Technology screening and alternative shortlisting, answering the question 'what are the most viable and cost effective technical approaches by which to recover and reuse energy from biosolids while reducing disposal volume?'; (2) Energy recovery and disposal reduction potential verification, answering the question 'how much energy can be recovered from biosolids?'; (3) Economic environmental and community benefit analysis, answering the question 'what are the potential economic, environmental and community benefits/impacts of each approach?'; and (4) Recommend the best plan and develop a concept design.

  6. Characteristic performance of radio-frequency(RF) plasma heating using inverter RF power supplies

    International Nuclear Information System (INIS)

    Imai, Takahiro; Uesugi, Yoshihiko; Takamura, Shuichi; Sawada, Hiroyuki; Hattori, Norifumi

    2000-01-01

    High heat flux plasma are produced by high powe (∼14 kW) ICRF heating using inverter power supplies in the linear divertor simulator NAGDIS-II. The power flow of radiated rf power is investigated by a calorimetric method. Conventional power calculation using antenna voltage and current gives that about 70% of the rf power is radiated into the plasma. But increase of the heat load at the target and anode is about 10% of the rf power. Through this experiment, we find that about half of the rf power is lost at the antenna surface through the formation of rf induced sheath. And about 30% of the power is lost into the vacuum vessel through the charge exchange and elastic collision of ions with neutrals. (author)

  7. Effect of Heat Generation of Ultrasound Transducer on Ultrasonic Power Measured by Calorimetric Method

    Science.gov (United States)

    Uchida, Takeyoshi; Kikuchi, Tsuneo

    2013-07-01

    Ultrasonic power is one of the key quantities closely related to the safety of medical ultrasonic equipment. An ultrasonic power standard is required for establishment of safety. Generally, an ultrasonic power standard below approximately 20 W is established by the radiation force balance (RFB) method as the most accurate measurement method. However, RFB is not suitable for high ultrasonic power because of thermal damage to the absorbing target. Consequently, an alternative method to RFB is required. We have been developing a measurement technique for high ultrasonic power by the calorimetric method. In this study, we examined the effect of heat generation of an ultrasound transducer on ultrasonic power measured by the calorimetric method. As a result, an excessively high ultrasonic power was measured owing to the effect of heat generation from internal loss in the transducer. A reference ultrasound transducer with low heat generation is required for a high ultrasonic power standard established by the calorimetric method.

  8. Development of small and medium reactors for power and heat production

    International Nuclear Information System (INIS)

    Becka, J.

    1978-01-01

    Data are given on the current state of development of small and medium-power reactors designed mainly for electric power production in small power grids, for heat production for small- and medium-power desalination plants with possible electric power generation, for process steam production and heat development for district heating systems, again combined with electric power generation, and for propelling big and fast passenger ships. A diagram is shown of the primary system of an integrated PWR derived from the Otto Hahn reactor. The family is listed of the standard sizes of the integral INTERATOM company pressurized water reactors. Also listed are the specifications and design of CAS 2CG and AS 3G type reactors used mainly for long-distance heating systems. (J.B.)

  9. Development and construction of nuclear power and nuclear heating stations in the USSR

    International Nuclear Information System (INIS)

    Schmidt, G.; Kirmse, B.

    1983-01-01

    The state-of-the-art of nuclear power technology in the USSR is reviewed by presenting characteristic data on design and construction. The review takes into consideration the following types of facilities: Nuclear power stations with 1000 MWe pressurized water reactors, with 1000 MWe pressure tube boiling water reactors, and with 600 MWe fast breeder reactors; nuclear heating power stations with 1000 MWe reactors and nuclear heating stations with 500 MWth boiling water reactors

  10. Heating power at room and building levels in passive houses and low-energy buildings

    OpenAIRE

    Rinholm, Jonas Myrberg

    2015-01-01

    This master thesis investigates the Norwegian standard for calculating necessary power demand, NS-EN 12831:2003- Varmesystemer i bygninger - Metode for beregning av dimensjonerende effektbehov. In that context, it is also investigated how power demand affects heating systems financially and environmentally, but also in terms of comfort and indoor air quality. Improved energy efficiency are leading to a reduction in the power demand for heating purposes in buildings. However, there are few...

  11. Fluid selection for the Organic Rankine Cycle (ORC) in biomass power and heat plants

    International Nuclear Information System (INIS)

    Drescher, Ulli; Brueggemann, Dieter

    2007-01-01

    In small solid biomass power and heat plants, the ORC is used for cogeneration. This application shows constraints different from other ORC. These constraints are described and an adapted power plant design is presented. The new design influences the selection criteria of working fluids. A software has been developed to find thermodynamic suitable fluids for ORC in biomass power and heat plants. Highest efficiencies are found within the family of alkylbenzenes

  12. Optimal Placement of A Heat Pump in An Integrated Power and Heat Energy System

    DEFF Research Database (Denmark)

    Klyapovskiy, Sergey; You, Shi; Bindner, Henrik W.

    2017-01-01

    With the present trend towards Smart Grids and Smart Energy Systems it is important to look for the opportunities for integrated development between different energy sectors, such as electricity, heating, gas and transportation. This paper investigates the problem of optimal placement of a heat...... pump – a component that links electric and heating utilities together. The system used to demonstrate the integrated planning approach has two neighboring 10kV feeders and several distribution substations with loads that require central heating from the heat pump. The optimal location is found...

  13. Quantity, Quality, and Availability of Waste Heat from United States Thermal Power Generation.

    Science.gov (United States)

    Gingerich, Daniel B; Mauter, Meagan S

    2015-07-21

    Secondary application of unconverted heat produced during electric power generation has the potential to improve the life-cycle fuel efficiency of the electric power industry and the sectors it serves. This work quantifies the residual heat (also known as waste heat) generated by U.S. thermal power plants and assesses the intermittency and transport issues that must be considered when planning to utilize this heat. Combining Energy Information Administration plant-level data with literature-reported process efficiency data, we develop estimates of the unconverted heat flux from individual U.S. thermal power plants in 2012. Together these power plants discharged an estimated 18.9 billion GJ(th) of residual heat in 2012, 4% of which was discharged at temperatures greater than 90 °C. We also characterize the temperature, spatial distribution, and temporal availability of this residual heat at the plant level and model the implications for the technical and economic feasibility of its end use. Increased implementation of flue gas desulfurization technologies at coal-fired facilities and the higher quality heat generated in the exhaust of natural gas fuel cycles are expected to increase the availability of residual heat generated by 10.6% in 2040.

  14. Nuclear power plant with improved arrangements for the removal of post fission and emergency heating

    International Nuclear Information System (INIS)

    Buescher, E.; Vinzens, K.

    1977-01-01

    This is concerned with additional equipment for emergency heat removal in a sodium cooled reactor, which operates on failure of the post fission heat removal system. The space for pressure relieving spaces and concrete masses as heat sinks within the reactor cell is no longer required. In this nuclear power plant, a heat exchanger chain transmits heat and power: There is a first sodium circuit between pressure vessel and the first heat exchanger, a second one between the first and second heat excahngers, and a third (Steam) circuit with turbine, condenser and return pump. A fourth circuit connects the secondary side of the condenser with a cooling tower. There is a threee component heat excahgner in the primary circuit after the first heat exchanger, which is built around the first heat exchanger, and is sealed into an unloading space. This space is situated next to the reactor cell and is above the operating level of the sodium in the pressure vessel. It is connected to the cell by an upper duct, normally closed by a bursting disc, and by a lower duct. In the three comopnent heat exchanger, a liquid lead-bismuth eutectic mixture transmits the heat from sodium pipes to water pipes. In normal operation it is used for steam superheating or feedwater preheating. The three component heat exchanger bridges the first and second heat exchangers as an emergency heat exchanger. If in such a case the post fission heat removal has failed, the sodium evaporating in the pressure vessel flows into the unloading space and condenses on the ribs of the emergency heat exchanger. The post fission heat is fed by the water secondary medium directly into the tertiary circuit. The sodium condensate flows back from the unloading space via the lower duct into the reactor cell and maintains the emergency level there. (RW) 891 RW [de

  15. Heat Pipe Powered Stirling Conversion for the Demonstration Using Flattop Fission (DUFF) Test

    Science.gov (United States)

    Gibson, Marc A.; Briggs, Maxwell H.; Sanzi, James L.; Brace, Michael H.

    2013-01-01

    Design concepts for small Fission Power Systems (FPS) have shown that heat pipe cooled reactors provide a passive, redundant, and lower mass option to transfer heat from the fuel to the power conversion system, as opposed to pumped loop designs typically associated with larger FPS. Although many systems have been conceptually designed and a few making it to electrically heated testing, none have been coupled to a real nuclear reactor. A demonstration test named DUFF Demonstration Using Flattop Fission, was planned by the Los Alamos National Lab (LANL) to use an existing criticality experiment named Flattop to provide the nuclear heat source. A team from the NASA Glenn Research Center designed, built, and tested a heat pipe and power conversion system to couple to Flattop with the end goal of making electrical power. This paper will focus on the design and testing performed in preparation for the DUFF test.

  16. Encouraging Combined Heat and Power in California Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Stadler, Michael [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Groissbock, Markus [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cardoso, Goncalo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Muller, Andreas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lai, Judy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2013-02-01

    Governor Brown’s research priorities include an additional 6.5 GW of combined heat and power (CHP) by 2030. As of 2009, roughly 0.25 GW of small natural gas and biogas fired CHP is documented by the Self-Generation Incentive Program (SGIP) database. The SGIP is set to expire, and the anticipated grid de-carbonization based on the development of 20 GW of renewable energy will influence the CHP adoption. Thus, an integrated optimization approach for this analysis was chosen that allows optimizing the adoption of distributed energy resources (DER) such as photovoltaics (PV), CHP, storage technologies, etc. in the California commercial sector from the building owners’ perspective. To solve this DER adoption problem the Distributed Energy Resources Customer Adoption Model (DER-CAM), developed by the Lawrence Berkeley National Laboratory and used extensively to address the problem of optimally investing and scheduling DER under multiple settings, has been used. The application of CHP at large industrial sites is well known, and much of its potential is already being realized. Conversely, commercial sector CHP, especially those above 50 to 100 kW peak electricity load, is widely overlooked. In order to analyze the role of DER in CO2 reduction, 147 representative sites in different climate zones were selected from the California Commercial End Use Survey (CEUS). About 8000 individual optimization runs, with different assumptions for the electric tariffs, natural gas costs, marginal grid CO2 emissions, and nitrogen oxide treatment costs, SGIP, fuel cell lifetime, fuel cell efficiency, PV installation costs, and payback periods for investments have been performed. The most optimistic CHP potential contribution in this sector in 2020 will be 2.7 GW. However, this result requires a SGIP in 2020, 46% average electric efficiency for fuel cells, a payback period for investments of 10 years, and a CO2 focused approach of the building owners. In

  17. On usage of heat-condensation type nuclear heat-and-power plants with the TK type turbines

    International Nuclear Information System (INIS)

    Boldyrev, V.M.; Smirnov, I.A.; Fedyaev, A.V.; Khrilev, L.S.

    1978-01-01

    The problems of the efficiency of nuclear heat-and-plants (NHPP) in the heat-andpower energetics of the USSR are discussed. Most attention is centered on an NHPP of heat-condensation type equipped with constant steam flow turbines of the TK-450/500-60 and K-500-60 types and WWER-1000 reactors. According to the specially developed procedure, the problem of selecting the profile of a TK-type turbine, NHPP composition and applications are subjected to the technico-economic analysis. The distance to the urban area from a central heat-and-power plant utilizing organic and atomic fuel is adopted to be the same and equal to 5, 10 and 15 km, and the thermal load is variable between 500 and 7000 Gcal/hour (the share of hot water supply load in the total thermal load being 0.2). The heat supply system is open-circuited, the hot/return water temperatures being 150/70 deg C. The optimum calculated heat production factor for the NHPP does not exceed 0.7, and the optimum heat production values from controlled turbine outputs are within 500-600 Gcal/hour. The mininum thermal load, for which the NHPP with TK turbines is more effective than an organic fuel heat-and-power station, is about 1000-1500 Gcal/hour if cooling towers are used in the technical water supply system, and if it is possible to construct a water reservoir-cooler for the NHPP, this range is reduced to a thermal load level, at which the combined system becomes more effective than the separate power generation systems, i.e. to 500-600 Gcal/hour

  18. Feasibility study on rehabilitation and improvement of thermal power plants, district heating and heat supply system in Botosani City

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    Discussions have been given on the improvement and modification project intended of saving energies and reducing greenhouse gas emission in the Botosani district heating and heat supplying facilities in Romania. Thirty years have elapsed since the building of the Botosani district heating and heat supplying facilities, whereas noticeable energy loss has occurred due to aged deterioration, such as thermal efficiency decrease, performance decrease, and hot water leakage due to piping corrosion. The present project is intended to improve the heat production and power generation facility efficiencies, and reduce the heat loss in heat transportation and distribution to less than 5%. The improvements will be implemented by replacing and rehabilitating the existing boilers, replacing the turbine generators, and replacing the transportation and distribution pipelines and heat exchangers. As a result of the discussions, the present project is estimated to result in annual fuel conservation of 35,820 tons of crude oil equivalent, and annual reduction of the greenhouse gas emission of 110,835 t-CO2. The total amount of the initial investment for the project would be 11.369 billion yen, and the payback period would be 12 years. The project will produce profit of 31.358 billion yen in 20 years, thus the project is financially feasible. (NEDO)

  19. High-power neutral-beam heating in the adiabatic toroidal compressor

    International Nuclear Information System (INIS)

    Ellis, R.A.; Eubank, H.P.; Goldston, R.; Smith, R.R.; Nagashima, T.

    1976-05-01

    Neutral-beam injection experiments on ATC have resulted in net power deposited in the plasma of up to 230 kW. The power deposited in the plasma ions is large compared to that from ohmic heating. For a variety of beam and plasma ion species, the increase in ion temperature is proportional to beam power

  20. DENINT power plant cost benefit analysis code: Analysis of methane fuelled power plant/district heating system

    International Nuclear Information System (INIS)

    Cincotti, V.; D'Andrea, A.

    1989-07-01

    The DENINT power plant cost benefit analysis code takes into consideration, not only power production costs at the generator terminals, but also, in the case of cogeneration, the costs of the fuel supply and heat and power distribution systems which depend greatly on the location of the plant. The code is able to allow comparisons of alternatives with varying annual operation hours, fuel cost increases, and different types of fossil fuels and production systems. For illustrative purposes, this paper examines two methane fired cogeneration plant/district heating alternatives

  1. Thermal power generation during heat cycle near room temperature

    Science.gov (United States)

    Shibata, Takayuki; Fukuzumi, Yuya; Kobayashi, Wataru; Moritomo, Yutaka

    2018-01-01

    We demonstrate that a sodium-ion secondary battery (SIB)-type thermocell consisting of two types of Prussian blue analogue (PBA) with different electrochemical thermoelectric coefficients (S EC ≡ ∂V/∂T V and T are the redox potential and temperature, respectively) produces electrical energy during heat cycles. The device produces an electrical energy of 2.3 meV/PBA per heat cycle between 295 K (= T L) and 323 K (= T H). The ideal thermal efficiency (η = 1.0%), which is evaluated using the heat capacity (C = 4.16 meV/K) of ideal Na2Co[Fe(CN)6], reaches 11% of the Carnot efficiency (ηth = 8.7%). Our SIB-type thermocell is a promising thermoelectric device that harvests waste heat near room temperature.

  2. Large heat storage tank for load management nd implementation of ambient heat. District heating networks based on combined heat and power; Grosswaermespeicher zum Lastmanagement und zur Einbindung von Umweltenergie. Auf KWK basierende Fernwaermenetze

    Energy Technology Data Exchange (ETDEWEB)

    Gross, Sebastian; Rhein, Martin; Ruehling, Karin [Technische Universitaet Dresden (Germany). Inst. fuer Energietechnik

    2013-06-15

    The district heating based on combined heat and power is a transitional technology on the way to the supply of Germany with renewable energy. In the next years, this transitional technology can only be maintained and expanded when marketability is given. Therefore an appropriate combination has to be found from investment measures. Together with new aspects in the management strategy, these investment measures should significantly improve the marketability. The investment measures also aims to enable a primary energetic, appropriate combination of natural gas-based combined heat and power, renewable energy sources (solar thermal energy, ambient heat) and heat pump technology.

  3. Heat and mass transfer and hydrodynamics in two-phase flows in nuclear power plants

    International Nuclear Information System (INIS)

    Styrikovich, M.A.; Polonskii, V.S.; Tsiklauri, G.V.

    1986-01-01

    This book examines nuclear power plant equipment from the point of view of heat and mass transfer and the behavior of impurities contained in water and in steam, with reference to real water regimes of nuclear power plants. The transfer processes of equipment are considered. Heat and mass transfer are analyzed in the pre-crisis regions of steam-generating passages with non-permeable surfaces, and in capillary-porous structures. Attention is given to forced convection boiling crises and top post-DNB heat transfer. Data on two-phase hydrodynamics in straight and curved channels are correlated and safety aspects of nuclear power plants are discussed

  4. Methods for planning and operating decentralized combined heat and power plants

    Energy Technology Data Exchange (ETDEWEB)

    Palsson, H.

    2000-02-01

    In recent years, the number of decentralized combined heat and power (DCHP) plants, which are typically located in small communities, has grown rapidly. These relatively small plants are based on Danish energy resources, mainly natural gas, and constitute an increasing part of the total energy production in Denmark. The topic of this thesis is the analysis of DCHP plants, with the purpose to optimize the operation of such plants. This involves the modelling of district heating systems, which are frequently connected to DCHP plants, as well as the use of heat storage for balancing between heat and power production. Furthermore, the accumulated effect from increasing number of DCHP plants on the total power production is considered. Methods for calculating dynamic temperature response in district heating (DH) pipes have been reviewed and analyzed numerically. Furthermore, it has been shown that a tree-structured DH network consisting of about one thousand pipes can be reduced to a simple chain structure of ten equivalent pipes without loosing much accuracy when temperature dynamics are calculated. A computationally efficient optimization method based on stochastic dynamic programming has been designed to find an optimum start-stop strategy for a DCHP plant with a heat storage. The method focuses on how to utilize heat storage in connection with CHP production. A model for the total power production in Eastern Denmark has been applied to the accumulated DCHP production. Probability production simulations have been extended from the traditional power-only analysis to include one or several heat supply areas. (au)

  5. Power, heat and chilliness with natural gas - fuel cells and air conditioning

    International Nuclear Information System (INIS)

    Krein, Stephan; Ruehling, Karin

    1999-01-01

    A new and innovative concept of the supply with power, heat and chilliness will realise in the new Malteser-hospital in Kamenz. The core of this demonstration-plant are a fuel cell, an adsorption cooling machine as well as multi-solar collectors. The fuel cell has two goals. Primary it produces power for the own demand. The selected dimension guarantees, that the power will consume nearly continuously. Secondly the produced heat of the fuel cell (and the solar-heat too) will use for heating and preparation of warm water. In the summer, the heat will use for the adsorption cooling machine, which produces chilliness for air-conditioning. The advantage in the face of common concepts of combining power and heat is the high-efficiently use of the fuel-energy for electric power generation on the one hand. Fuel cells work with high efficiency also at partial load. On the other hand, with the adsorption cooling machine the produced heat of fuel cell and multi-solar collectors can be used also in the summer. First experiences with this concept show, that an optimised co-operation of the components with an adaptive, self-learning control system based on the weather forecast as well as various storages for heat and chilliness can be achieve. A continuously operation, high fuel utilisation and reduced environmental pollution can be demonstrated. (author)

  6. Membrane-based osmotic heat engine with organic solvent for enhanced power generation from low-grade heat.

    Science.gov (United States)

    Shaulsky, Evyatar; Boo, Chanhee; Lin, Shihong; Elimelech, Menachem

    2015-05-05

    We present a hybrid osmotic heat engine (OHE) system that uses draw solutions with an organic solvent for enhanced thermal separation efficiency. The hybrid OHE system produces sustainable energy by combining pressure-retarded osmosis (PRO) as a power generation stage and membrane distillation (MD) utilizing low-grade heat as a separation stage. While previous OHE systems employed aqueous electrolyte draw solutions, using methanol as a solvent is advantageous because methanol is highly volatile and has a lower heat capacity and enthalpy of vaporization than water. Hence, the thermal separation efficiency of a draw solution with methanol would be higher than that of an aqueous draw solution. In this study, we evaluated the performance of LiCl-methanol as a potential draw solution for a PRO-MD hybrid OHE system. The membrane transport properties as well as performance with LiCl-methanol draw solution were evaluated using thin-film composite (TFC) PRO membranes and compared to the results obtained with a LiCl-water draw solution. Experimental PRO methanol flux and maximum projected power density of 47.1 L m(-2) h(-1) and 72.1 W m(-2), respectively, were achieved with a 3 M LiCl-methanol draw solution. The overall efficiency of the hybrid OHE system was modeled by coupling the mass and energy flows between the thermal separation (MD) and power generation (PRO) stages under conditions with and without heat recovery. The modeling results demonstrate higher OHE energy efficiency with the LiCl-methanol draw solution compared to that with the LiCl-water draw solution under practical operating conditions (i.e., heat recovery<90%). We discuss the implications of the results for converting low-grade heat to power.

  7. Membrane-Based Osmotic Heat Engine with Organic Solvent for Enhanced Power Generation from Low-Grade Heat

    Energy Technology Data Exchange (ETDEWEB)

    Shaulsky, E; Boo, C; Lin, SH; Elimelech, M

    2015-05-05

    We present a hybrid osmotic heat engine (OHE) system that uses draw solutions with an organic solvent for enhanced thermal separation efficiency. The hybrid OHE system produces sustainable energy by combining pressure-retarded osmosis (PRO) as a power generation stage and membrane distillation (MD) utilizing low-grade heat as a separation stage. While previous OHE systems employed aqueous electrolyte draw solutions, using methanol as a solvent is advantageous because methanol is highly volatile and has a lower heat capacity and enthalpy of vaporization than water. Hence, the thermal separation efficiency of a draw solution with methanol would be higher than that of an aqueous draw solution. In this study, we evaluated the performance of LiCl-methanol as a potential draw solution for a PRO-MD hybrid OHE system. The membrane transport properties as well as performance with LiCl methanol draw solution were evaluated using thin-film composite (TFC) PRO membranes and compared to the results obtained with a LiCl water draw solution. Experimental PRO methanol flux and maximum projected power density of 47.1 L m(-2) h(-1) and 72.1 W m(-2), respectively, were achieved with a 3 M LiCl-methanol draw solution. The overall efficiency of the hybrid OHE system was modeled by coupling the mass and energy flows between the thermal separation (MD) and power generation (PRO) stages under conditions with and without heat recovery. The modeling results demonstrate higher ORE energy efficiency with the LiCl methanol draw solution compared to that with the LiCl water draw solution under practical operating conditions (i.e., heat recovery <90%). We discuss the implications of the results for converting low-grade heat to power.

  8. Potentials for heat accumulators in thermal power plants; Potenziale fuer Waermespeicher in Heiz(kraft)werken

    Energy Technology Data Exchange (ETDEWEB)

    Dengel, Andreas [STEAG New Energies GmbH, Saarbruecken (Germany)

    2012-07-01

    STEAG New Energies GmbH (Saarbruecken, Federal Republic of Germany) is contractor and operator of a variety of decentralized plants for heat production and power generation. The customers consist of communities, cooperation associations, business enterprises as well as industrial enterprises. Beside merely heat generators, so-called heat and power cogeneration plants often are used. The power generation is of minor importance due to the heat-controlled energy supply of the customers. Biomass power plants being operated in line with the Renewable Energy Law are an exemption. The demand for regulating energy increased clearly due to the enhanced volatile feeding of regenerative produced electric power. If the operation of heat and power cogeneration plants becomes more independent from the actual energy demand by using energy storages, then the energy transducer can be implemented in the lucrative market of regulation energy supply. Thus, the potential of such storages at the sites within a company shall be determined. Additionally, the development and testing of a latent heat accumulator for a thermal power plant of the company supplying process vapour with a temperature of 300 Celsius to a foil manufacturing facility is envisaged.

  9. Model for optimization of plant investments in combined power and heat production systems

    Energy Technology Data Exchange (ETDEWEB)

    Jantunen, E.; Sinisalo, A.; Koskelainen, L.

    1980-01-01

    A mathematical model is developed for optimal dimensioning and timing the investments of power and heat production system in a community. The required electric power may be purchased by different production systems, such as: thermal power plants, gas turbines, diesel plants, etc. or by delivering all or part of it from a national power company. Also the required heat may be produced in many different ways in single-purpose or combined plants. The model assumes the extent of the heating system fixed, and it is not optimized. It is assumed that the same company is responsible for supplying both the power and heat for the community. It's aim is to allocate the existing capital in an optimal way, and the model may be used for facilitating the decision in such questions as: what kind of production capacity should be purchased in future; how high should the heat and power capacities be; and when should this additional capacity be available. The report also reviews the methods for forecasting the demand of power and heat and their fluctuation during the planning period. The solution of this large-scale non-linear optimization problem is searched via successive linearizations by using the Method of Approximate Programming (MAP). It was found that the solution method is very suitable for this kind of multivariable problems. The computing times with the Functional Mathematical Programmin System (FMPS) in Univac 1108 computer were quite reasonable.

  10. Steam turbines for nuclear power stations in Czechoslovakia and their use for district heating

    International Nuclear Information System (INIS)

    Drahy, J.

    1989-01-01

    The first generation of nuclear power stations in Czechoslavakia is equipped with 440 MW e pressurized water reactors. Each reactor supplies two 220 MW, 3000 rpm condensing type turbosets operating with saturated steam. After the completion of heating water piping systems, all of the 24 units of 220 MW in Czechoslovak nuclear power stations will be operated as dual purpose units, delivering both electricity and heat. At the present time, second-generation nuclear power stations, with 1000 MW e PWRs, are being built. Each such plant is equipped with one 1000 MW full-speed saturated steam turbine. The turbine is so designed as to permit the extraction of steam corresponding to the following quantities of heat: 893 MJ/s with three-stage water heating (150/60 0 C); and 570 MJ/s with two-stage water heating (120/60 0 C). The steam is taken from uncontrolled steam extraction points. (author)

  11. Technical assessment of electric heat boosters in low-temperature district heating based on combined heat and power analysis

    DEFF Research Database (Denmark)

    Cai, Hanmin; You, Shi; Wang, Jiawei

    2018-01-01

    This paper provides a technical assessment of electric heat boosters (EHBs) in low-energy districts. The analysis is based on a hypothetical district with 23 terraced single-family houses supplied by both a lowtemperature district heating (LTDH) network and a low-voltage network (LVN). Two case...

  12. Combined heat and power and solar energy; BHKW und solare Energie

    Energy Technology Data Exchange (ETDEWEB)

    Marchesi, M.; Schmidt, A.

    2006-07-01

    This illustrated article takes a look at a new apartment complex in Buelach, Switzerland, that meets the 'Minergie' low energy-consumption standard and also features solar-thermal heat generation. This solar installation provides heat for the provision of domestic hot water and, also, heat for the space-heating system of the building complex. The solar collectors cover an area of 153 m{sup 2}; their power is rated at 96 kW. Further elements of the building's technical services include a combined heat and power plant, a heat-pump and a gas-fired boiler. The article discusses ecological and social aspects of the design and construction of the building complex and briefly describes the installations, which also include a 'Minergie' fan-assisted balanced ventilation system.

  13. Evaporation and condensation devices for passive heat removal systems in nuclear power engineering

    International Nuclear Information System (INIS)

    Gershuni, A.N.; Pis'mennyj, E.N.; Nishchik, A.P.

    2016-01-01

    The paper justifies advantages of evaporation and condensation heat transfer devices as means of passive heat removal and thermal shielding in nuclear power engineering. The main thermophysical factors that limit heat transfer capacity of evaporation and condensation systems have been examined in the research. The results of experimental studies of heat engineering properties of elongated (8-m) vertically oriented evaporation and condensation devices (two-phase thermosyphons), which showed a high enough heat transfer capacity, as well as stability and reliability both in steady state and in start-up modes, are provided. The paper presents the examples of schematic designs of evaporation and condensation systems for passive heat removal and thermal shielding in application to nuclear power equipment

  14. Economical Efficiency of Combined Cooling Heating and Power Systems Based on an Enthalpy Method

    Directory of Open Access Journals (Sweden)

    Yan Xu

    2017-11-01

    Full Text Available As the living standards of Chinese people have been improving, the energy demand for cooling and heating, mainly in the form of electricity, has also expanded. Since an integrated cooling, heating and power supply system (CCHP will serve this demand better, the government is now attaching more importance to the application of CCHP energy systems. Based on the characteristics of the combined cooling heating and power supply system, and the method of levelized cost of energy, two calculation methods for the evaluation of the economical efficiency of the system are employed when the energy production in the system is dealt with from the perspective of exergy. According to the first method, fuel costs account for about 75% of the total cost. In the second method, the profits from heating and cooling are converted to fuel costs, resulting in a significant reduction of fuel costs, accounting for 60% of the total cost. Then the heating and cooling parameters of gas turbine exhaust, heat recovery boiler, lithium-bromide heat-cooler and commercial tariff of provincial capitals were set as benchmark based on geographic differences among provinces, and the economical efficiency of combined cooling heating and power systems in each province were evaluated. The results shows that the combined cooling heating and power system is economical in the developed areas of central and eastern China, especially in Hubei and Zhejiang provinces, while in other regions it is not. The sensitivity analysis was also made on related influencing factors of fuel cost, demand intensity in heating and cooling energy, and bank loans ratio. The analysis shows that the levelized cost of energy of combined cooling heating and power systems is very sensitive to exergy consumption and fuel costs. When the consumption of heating and cooling energy increases, the unit cost decreases by 0.1 yuan/kWh, and when the on-grid power ratio decreases by 20%, the cost may increase by 0.1 yuan

  15. Heat transfer enhancement of a modularised thermoelectric power generator for passenger vehicles

    International Nuclear Information System (INIS)

    Li, Bo; Huang, Kuo; Yan, Yuying; Li, Yong; Twaha, Ssennoga; Zhu, Jie

    2017-01-01

    Highlights: •Shape-adapted thermoelectric module for highly compact heat recovery exchanger assembly. •Heat pipe-assisted heat transfer enhancement method for better power output. •Highest power output ratio to the total volume of heat recovery exchanger. •Cascaded thermoelectric system can be scaled and extended for various power output. •Self-clamping design of thermoelectric module can solve the thermomechanical imbalances. -- Abstract: Transport represents over a quarter of Europe's greenhouse gas emissions and is the leading cause of air pollution in cities. It has not seen the same gradual decline in emissions as other sectors. Recently, the thermoelectric power generation (TEG) technology emerges as an alternative solution to the emission reduction challenge in this area. In this paper, we present an innovative pathway to an improved heat supply into the concentric shape-adapted TEG modules, integrating the heat pipe technologies. It relies on a phase changing approach which enhances the heat flux through the TEG surface. In order to improve the heat transfer for higher efficiency, in our work, the heat pipes are configured in the radial direction of the exhaust streams. The analysis shows that the power output is adequate for the limited space under the chassis of the passenger car. Much effort can also be applied to obtain enhanced convective heat transfer by adjusting the heat pipes at the dual sides of the concentric TEG modules. Heat enhancement at the hot side of the TEG has an effective impact on the total power out of the TEG modules. However, such improvements can be offset by the adjustment made from the coolant side. Predictably, the whole temperature profile of TEG system is subject to the durability and operational limitations of each component. Furthermore, the results highlight the importance of heat transfer versus the TEG power generation under two possible configurations in the passenger car. The highest power output per

  16. Sandwich Core Heat-Pipe Radiator for Power and Propulsion Systems

    Science.gov (United States)

    Gibson, Marc; Sanzi, James; Locci, Ivan

    2013-01-01

    Next-generation heat-pipe radiator technologies are being developed at the NASA Glenn Research Center to provide advancements in heat-rejection systems for space power and propulsion systems. All spacecraft power and propulsion systems require their waste heat to be rejected to space in order to function at their desired design conditions. The thermal efficiency of these heat-rejection systems, balanced with structural requirements, directly affect the total mass of the system. Terrestrially, this technology could be used for thermal control of structural systems. One potential use is radiant heating systems for residential and commercial applications. The thin cross section and efficient heat transportability could easily be applied to flooring and wall structures that could evenly heat large surface areas. Using this heat-pipe technology, the evaporator of the radiators could be heated using any household heat source (electric, gas, etc.), which would vaporize the internal working fluid and carry the heat to the condenser sections (walls and/or floors). The temperature could be easily controlled, providing a comfortable and affordable living environment. Investigating the appropriate materials and working fluids is needed to determine this application's potential success and usage.

  17. Applicability of advanced automotive heat engines to solar thermal power

    Science.gov (United States)

    Beremand, D. G.; Evans, D. G.; Alger, D. L.

    The requirements of a solar thermal power system are reviewed and compared with the predicted characteristics of automobile engines under development. A good match is found in terms of power level and efficiency when the automobile engines, designed for maximum powers of 65-100 kW (87 to 133 hp) are operated to the nominal 20-40 kW electric output requirement of the solar thermal application. At these reduced power levels it appears that the automotive gas turbine and Stirling engines have the potential to deliver the 40+ percent efficiency goal of the solar thermal program.

  18. Solar powered absorption cycle heat pump using phase change materials for energy storage

    Science.gov (United States)

    Middleton, R. L.

    1972-01-01

    Solar powered heating and cooling system with possible application to residential homes is described. Operating principles of system are defined and illustration of typical energy storage and exchange system is provided.

  19. Recent DIII-D high power heating and current drive experiments

    International Nuclear Information System (INIS)

    Simonen, T.C.; Jackson, G.L.; Lazarus, E.A.; Mahdavi, M.A.; Petrie, T.W.; Politzer, P.A.; Taylor, T.S.

    1995-01-01

    This paper describes recent DIII-D high power heating and current drive experiments. Described are experiments with improved wall conditioning, divertor particle pumping, radiative divertor experiments, studies of plasma shape and high poloidal β. ((orig.))

  20. Recent DIII-D high power heating and current drive experiments

    International Nuclear Information System (INIS)

    Simonen, T.C.; Jackson, G.L.; Mahdavi, M.A.; Petrie, T.W.; Politzer, P.A.; Taylor, T.S.; Lazarus, E.A.

    1994-02-01

    This paper describes recent DIII-D high power heating and current drive experiments. Describes are experiments with improved wall conditioning, divertor particle pumping, radiative divertor experiments, studies of plasma shape and high poloidal beta

  1. Recent DIII-D high power heating and current drive experiments

    Energy Technology Data Exchange (ETDEWEB)

    Simonen, T.C. [General Atomics, San Diego, CA (United States); Jackson, G.L. [General Atomics, San Diego, CA (United States); Lazarus, E.A. [Oak Ridge National Lab., TN (United States); Mahdavi, M.A. [General Atomics, San Diego, CA (United States); Petrie, T.W. [General Atomics, San Diego, CA (United States); Politzer, P.A. [General Atomics, San Diego, CA (United States); Taylor, T.S. [General Atomics, San Diego, CA (United States); DIII-D Team

    1995-01-01

    This paper describes recent DIII-D high power heating and current drive experiments. Described are experiments with improved wall conditioning, divertor particle pumping, radiative divertor experiments, studies of plasma shape and high poloidal {beta}. ((orig.)).

  2. Heat Transfer Characteristics in High Power LED Packaging

    Directory of Open Access Journals (Sweden)

    Chi-Hung Chung

    2014-03-01

    Full Text Available This study uses the T3Ster transient thermal resistance measuring device to investigate the effects to heat transfer performances from different LED crystal grains, packaging methods and heat-sink substrates through the experimental method. The experimental parameters are six different types of LED modules that are made alternatively with the crystal grain structure, the die attach method and the carrying substrate. The crystal grain structure includes the lateral type, flip chip type and vertical type. The die attach method includes silver paste and the eutectic structure. The carrying substrates are aluminum oxide (Alumina and aluminum nitride (AIN ceramic substrates and metal core PCB (MCPCB. The experimental results show that, under the conditions of the same crystal grain and die attach method, the thermal resistance values for the AIN substrate and the Alumina substrate are 2.1K/W and 5.1K/W, respectively and the total thermal resistance values are 7.3K/W and 10.8K/W. Compared to the Alumina substrate, the AIN substrate can effectively lower the total thermal resistance value by 32.4%. This is because the heat transfer coefficient of the AIN substrate is higher than that of the Alumina substrate, thus effectively increasing its thermal conductivity. In addition, under the conditions of the same crystal grain and the same substrate, the packaging methods are using silver paste and the eutectic structure for die attach. Their thermal resistance values are 5.7K/W and 2.7K/W, respectively, with a variance of 3K/W. Comparisons of the crystal grain structure show that the thermal resistance for the flip chip type is lower than that of the traditional lateral type by 0.9K/W. This is because the light emitting layer of the flip chip crystal grain is closer to the heat-sink substrate, shortening the heat dissipation route, and thus lowering the thermal resistance value. For the total thermal resistance, the crystal grain structure has a lesser

  3. Performance predictions and measurements for space-power-system heat pipes

    International Nuclear Information System (INIS)

    Prenger, F.C. Jr.

    1981-01-01

    High temperature liquid metal heat pipes designed for space power systems have been analyzed and tested. Three wick designs are discussed and a design rationale for the heat pipe is provided. Test results on a molybdenum, annular wick heat pipe are presented. Performance limitations due to boiling and capillary limits are presented. There is evidence that the vapor flow in the adiabatic section is turbulent and that the transition Reynolds number is 4000

  4. Steam condensation process in a power production cycle and heat exchanger for it

    International Nuclear Information System (INIS)

    Tondeur, Gerard; Andro, Jean; Marjollet, Jacques; Pouderoux, Pierre.

    1982-01-01

    Steam condensation process in a power production cycle by expansion in turbines, characterized by the fact that this condensation is performed by the vaporization of a coolant with a vaporization temperature at atmospheric pressure lower than that of water, and that the vaporized coolant fluid is expanded in a turbine and then condensed by heat exchange with cold water being heated, while the liquefied coolant is recompressed and used for heat exchange with the steam to be condensed [fr

  5. Duct burners in heat recovery system for cogeneration and captive power plants

    International Nuclear Information System (INIS)

    Majumdar, J.

    1992-01-01

    Our oil explorations both onshore and offshore have thrown open bright prospects of cogeneration by using natural gas in gas turbine power plants with heat recovery units. Both for co-gen and combined cycle systems, supplementary firing of GT exhaust gas is normally required. Hence, duct burners have significant role for effective contribution towards of efficacy of heat recovery system for gas turbine exhaust gas. This article details on various aspects of duct burners in heat recovery systems. (author)

  6. Numerical and experimental analysis of heat pipes with application in concentrated solar power systems

    Science.gov (United States)

    Mahdavi, Mahboobe

    Thermal energy storage systems as an integral part of concentrated solar power plants improve the performance of the system by mitigating the mismatch between the energy supply and the energy demand. Using a phase change material (PCM) to store energy increases the energy density, hence, reduces the size and cost of the system. However, the performance is limited by the low thermal conductivity of the PCM, which decreases the heat transfer rate between the heat source and PCM, which therefore prolongs the melting, or solidification process, and results in overheating the interface wall. To address this issue, heat pipes are embedded in the PCM to enhance the heat transfer from the receiver to the PCM, and from the PCM to the heat sink during charging and discharging processes, respectively. In the current study, the thermal-fluid phenomenon inside a heat pipe was investigated. The heat pipe network is specifically configured to be implemented in a thermal energy storage unit for a concentrated solar power system. The configuration allows for simultaneous power generation and energy storage for later use. The network is composed of a main heat pipe and an array of secondary heat pipes. The primary heat pipe has a disk-shaped evaporator and a disk-shaped condenser, which are connected via an adiabatic section. The secondary heat pipes are attached to the condenser of the primary heat pipe and they are surrounded by PCM. The other side of the condenser is connected to a heat engine and serves as its heat acceptor. The applied thermal energy to the disk-shaped evaporator changes the phase of working fluid in the wick structure from liquid to vapor. The vapor pressure drives it through the adiabatic section to the condenser where the vapor condenses and releases its heat to a heat engine. It should be noted that the condensed working fluid is returned to the evaporator by the capillary forces of the wick. The extra heat is then delivered to the phase change material

  7. Harmony search algorithm for solving combined heat and power economic dispatch problems

    Energy Technology Data Exchange (ETDEWEB)

    Khorram, Esmaile, E-mail: eskhor@aut.ac.i [Department of Applied Mathematics, Faculty of Mathematics and Computer Science, Amirkabir University of Technology, No. 424, Hafez Ave., 15914 Tehran (Iran, Islamic Republic of); Jaberipour, Majid, E-mail: Majid.Jaberipour@gmail.co [Department of Applied Mathematics, Faculty of Mathematics and Computer Science, Amirkabir University of Technology, No. 424, Hafez Ave., 15914 Tehran (Iran, Islamic Republic of)

    2011-02-15

    Economic dispatch (ED) is one of the key optimization problems in electric power system operation. The problem grows complex if one or more units produce both power and heat. Combined heat and power economic dispatch (CHPED) problem is a complicated problem that needs powerful methods to solve. This paper presents a harmony search (EDHS) algorithm to solve CHPED. Some standard examples are presented to demonstrate the effectiveness of this algorithm in obtaining the optimal solution. In all cases, the solutions obtained using EDHS algorithm are better than those obtained by other methods.

  8. Implementation of heat production and storage technology and devices in power systems

    International Nuclear Information System (INIS)

    Romanovsky, G.; Mutale, J.

    2012-01-01

    Implementation of heat storage devices and technologies at power generation plants is a promising way to provide more efficient use of natural energy resources. Heat storage devices can partly replace conventional heating technologies (such as direct use of fossil fuels) during peak energy demand or in the situations where heat and electricity supply and demand do not coincide and to obtain low cost heat energy which can be further transmitted to industrial, commercial and domestic consumers. This paper presents the innovative Heat Production and Storage Device and its application at conventional, nuclear and renewable power generation plants for optimization and balancing of electricity grids. The Heat Production and Storage Device is a vessel type induction-immersion heat production and storage device which produces pre-heated water under pressure for heat energy conservation. Operation of this device is based on simultaneous and/or sequential action of an inductor and an immersion heater and can be easily connected to the electricity network as a single or a three phase unit. Heat energy accumulated by the Heat Production and Storage Device can be utilized in different industrial technological processes during periods of high energy prices. - Highlights: ► Heat Production and Storage Device for energy conservation within low load hours. ► Simultaneous and/or sequential operation of the inductor and immersion heater. ► Transform the energy of low frequency electrical current (50 Hz) into heat energy. ► Connection to the electricity network either in single or three phase unit. ► Heat Production and Storage Device will enhance the economic value of the system.

  9. A study on heat transfer enhancement using flow channel inserts for thermoelectric power generation

    International Nuclear Information System (INIS)

    Lesage, Frédéric J.; Sempels, Éric V.; Lalande-Bertrand, Nathaniel

    2013-01-01

    Highlights: • Thermal enhancement in a thermoelectric liquid generator is tested. • Thermal enhancement is brought upon by flow impeding inserts. • CFD simulations attribute thermal enhancement to velocity field alterations. • Thermoelectric power enhancement is measured and discussed. • Power enhancement relative to adverse pressure drop is investigated. - Abstract: Thermoelectric power production has many potential applications that range from microelectronics heat management to large scale industrial waste-heat recovery. A low thermoelectric conversion efficiency of the current state of the art prevents wide spread use of thermoelectric modules. The difficulties lie in material conversion efficiency, module design, and thermal system management. The present study investigates thermoelectric power improvement due to heat transfer enhancement at the channel walls of a liquid-to-liquid thermoelectric generator brought upon by flow turbulating inserts. Care is taken to measure the adverse pressure drop due to the presence of flow impeding obstacles in order to measure the net thermoelectric power enhancement relative to an absence of inserts. The results illustrate the power enhancement performance of three different geometric forms fitted into the channels of a thermoelectric generator. Spiral inserts are shown to offer a minimal improvement in thermoelectric power production whereas inserts with protruding panels are shown to be the most effective. Measurements of the thermal enhancement factor which represents the ratio of heat flux into heat flux out of a channel and numerical simulations of the internal flow velocity field attribute the thermal enhancement resulting in the thermoelectric power improvement to thermal and velocity field synergy

  10. A thermoelectric power generating heat exchanger: Part I – Experimental realization

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Sarhadi, Ali; Pryds, Nini

    2016-01-01

    An experimental realization of a heat exchanger with commercial thermoelectric generators (TEGs) is presented. The power producing capabilities as a function of flow rate and temperature span are characterized for two different commercial heat transfer fluids and for three different thermal...

  11. Power/heat production from biomass in Finland - Two modern Finnish examples

    International Nuclear Information System (INIS)

    Aeijaelae, M.

    1997-01-01

    According to this conference paper, Finland is a leading country in the utilization of biomass fuels for power and heat production. One reason is that peat and wood are the only indigenous fuels available in Finland. Other reasons are the strong forest industry and the widely adopted combined heat and power (CHP) production. CHP production is typical of process industry and municipal district heating. The most common boiler type in modern CHP plants is the fluidized bed type. District heating is the cheapest heating in municipalities with a few thousand inhabitants. Electric heating dominates in sparsely populated regions. CHP becomes attractive for populations of more than ten thousand. Two examples are described: (1) Rauhalahti Power Plant produces 140 MW of district heat, 65 MW of industrial steam and 87 MW of electricity. (2) Kuusamo Power Plant produces 6.1 MW electric energy and 17.6 MW district heat; its unique feature is the utilization of the bed mixing dryer for drying of the fuel prior to combustion, this dryer being the first of its kind in the world. 1 figure

  12. Forum environmental and energy technology 2013. Power-heat cogeneration and air pollution prevention

    International Nuclear Information System (INIS)

    Carlowitz, Otto; Meyer, Sven

    2013-01-01

    The volume covers the following topics: The teaching reward 2013 - concept and implementation of the ''Forum environmental and energy technology''; energy efficient air pollution control and material recovery; air pollution control by oxidation; electrical energy production from low-temperature waste heat (ORC processes), electrical power production and process heat utilization.

  13. Modeling and analysis of a transcritical rankine power cycle with a low grade heat source

    DEFF Research Database (Denmark)

    Nguyen, Chan; Veje, Christian

    efficiency, exergetic efficiency and specific net power output. A generic cycle configuration has been used for analysis of a geothermal energy heat source. This model has been validated against similar calculations using industrial waste heat as the energy source. Calculations are done with fixed...

  14. Design and modelling of a novel compact power cycle for low temperature heat sources

    DEFF Research Database (Denmark)

    Wronski, Jorrit; Skovrup, Morten Juel; Elmegaard, Brian

    2012-01-01

    Power cycles for the efficient use of low temperature heat sources experience increasing attention. This paper describes an alternative cycle design that offers potential advantages in terms of heat source exploitation. A concept for a reciprocating expander is presented that performs both, work ...

  15. The market potential of modular HTRs as heat and power sources in Spain

    International Nuclear Information System (INIS)

    Albisu, F.

    1991-01-01

    The state of energy in Spain in mid-1990 is analysed, first in overall fashion and then with more specific attention to the areas in which HTR systems might be deployed: (i) generation of electricity for the peninsula and for the archipelagos; (ii) cogeneration (or combined heat and power production) in industry; (iii) district heating; (iv) desalination of sea water

  16. Numerical analyses of the effect of a biphasic thermosyphon vapor channel sizes on the heat transfer intensity when heat removing from a power transformer of combined heat and power station

    Directory of Open Access Journals (Sweden)

    Nurpeiis Atlant

    2017-01-01

    Full Text Available Numerical analyses of the effect of a biphasic thermosyphon vapor channel sizes on the heat transfer intensity was conducted when heat removing from an oil tank of a power transformer of combined heat and power station (CHP. The power transformer cooling system by the closed biphasic thermosyphon was proposed. The mathematical modeling of heat transfer and phase transitions of coolant in the thermosyphon was performed. The problem of heat transfer is formulated in dimensionless variables “velocity vorticity vector – current function – temperature” and solved by finite difference method. As a result of numerical simulation it is found that an increase in the vapor channel length from 0.15m to 1m leads to increasing the temperature difference by 3.5 K.

  17. Combined heat and power production through biomass gasification with 'Heatpipe-Reformer'

    International Nuclear Information System (INIS)

    Iliev, I.; Kamburova, V.; Terziev, A.

    2013-01-01

    The current report aims is to analyze the system for combined heat and power production through biomass gasification with “heatpipe-reformer” system. Special attention is paid on the process of synthetic gas production in the Reformer, its cleaning and further burning in the co-generation unit. A financial analysis is made regarding the investments and profits generated by the combined heat and power production. (authors)

  18. Combined Heat and Power Systems for the Provision of Sustainable Energy from Biomass in Buildings

    OpenAIRE

    Ortwein Andreas

    2016-01-01

    Against the background of greenhouse gases causing climate change, combined heat and power (CHP) systems fueled by biomass can efficiently supply energy with high flexibility. Such CHP systems will usually consist of one or more thermo-chemical conversion steps and at least one (the more or less separated) electric power generation unit. Depending on the main products of the previous conversion steps (e.g. combustible gases or liquids, but also flue gases with sensible heat), different techno...

  19. Target study of heat supply from Northern Moravia nuclear power plant

    International Nuclear Information System (INIS)

    Pospisil, V.

    The construction is envisaged in Northern Moravia of a nuclear power plant near Blahutovice in the Novy Jicin district. Heat produced by the nuclear power plant will only be used for district heating; process heat will be supplied from local steam sources. An example is discussed of the Prerov locality which currently is supplied from the Prerov heating and power plant (230 MW), a heating plant (36 MW) and from local sources (15 NW). The study estimates that a thermal power of 430 MW will be required at a time of the start of heat supplies from the nuclear power plant. All heat supply pipelines will be designed as a two-tube system divided into sections with section pipe fittings. The number and location of pipe fittings will be selected depending on the terrain configuration. Water of the maximum outlet temperature of 150 degC will be used as a coolant. The control of the system for Northern Moravia is briefly described. (J.P.)

  20. Maximum-power-point tracking control of solar heating system

    KAUST Repository

    Huang, Bin-Juine; Ton, Wei-Zhe; Wu, Chen-Chun; Ko, Hua-Wei; Chang, Hsien-Shun; Yen, Rue-Her; Wang, Jiunn-Cherng

    2012-01-01

    was used to determine the instantaneous tracking target Q max(t). The system transfer-function model of solar heating system was also derived experimentally using a step response test and used in the design of tracking feedback control system. The PI

  1. Accelerating the energy policy turnaround with combined heat and power units; Mit Blockheizkraftwerken die Energiewende rund machen

    Energy Technology Data Exchange (ETDEWEB)

    Lange, Joerg; Geiler, Nikolaus [Klimabuendnis Freiburg, Freiburg im Breisgau (Germany)

    2013-03-15

    No other type of decentralized power plants transforms natural gas to electric power so efficiently as a combined heat and power unit. In the long term, the climate-friendly effect using renewable hydrogen or renewably generated 'natural gas' even could be increased. Thus, combined heat and power units are ideal to achieve the national climate change objectives. Despite their advantages, the implementation of combined heat and power units advances only sluggishly.

  2. Heat exchanger inventory cost optimization for power cycles with one feedwater heater

    International Nuclear Information System (INIS)

    Qureshi, Bilal Ahmed; Antar, Mohamed A.; Zubair, Syed M.

    2014-01-01

    Highlights: • Cost optimization of heat exchanger inventory in power cycles is investigated. • Analysis for an endoreversible power cycle with an open feedwater heater is shown. • Different constraints on the power cycle are investigated. • The constant heat addition scenario resulted in the lowest value of the cost function. - Abstract: Cost optimization of heat exchanger inventory in power cycles with one open feedwater heater is undertaken. In this regard, thermoeconomic analysis for an endoreversible power cycle with an open feedwater heater is shown. The scenarios of constant heat rejection and addition rates, power as well as rate of heat transfer in the open feedwater heater are studied. All cost functions displayed minima with respect to the high-side absolute temperature ratio (θ 1 ). In this case, the effect of the Carnot temperature ratio (Φ 1 ), absolute temperature ratio (ξ) and the phase-change absolute temperature ratio for the feedwater heater (Φ 2 ) are qualitatively the same. Furthermore, the constant heat addition scenario resulted in the lowest value of the cost function. For variation of all cost functions, the smaller the value of the phase-change absolute temperature ratio for the feedwater heater (Φ 2 ), lower the cost at the minima. As feedwater heater to hot end unit cost ratio decreases, the minimum total conductance required increases

  3. A Benders decomposition approach for a combined heat and power economic dispatch

    International Nuclear Information System (INIS)

    Abdolmohammadi, Hamid Reza; Kazemi, Ahad

    2013-01-01

    Highlights: • Benders decomposition algorithm to solve combined heat and power economic dispatch. • Decomposing the CHPED problem into master problem and subproblem. • Considering non-convex heat-power feasible region efficiently. • Solving 4 units and 5 units system with 2 and 3 co-generation units, respectively. • Obtaining better or as well results in terms of objective values. - Abstract: Recently, cogeneration units have played an increasingly important role in the utility industry. Therefore the optimal utilization of multiple combined heat and power (CHP) systems is an important optimization task in power system operation. Unlike power economic dispatch, which has a single equality constraint, two equality constraints must be met in combined heat and power economic dispatch (CHPED) problem. Moreover, in the cogeneration units, the power capacity limits are functions of the unit heat productions and the heat capacity limits are functions of the unit power generations. Thus, CHPED is a complicated optimization problem. In this paper, an algorithm based on Benders decomposition (BD) is proposed to solve the economic dispatch (ED) problem for cogeneration systems. In the proposed method, combined heat and power economic dispatch problem is decomposed into a master problem and subproblem. The subproblem generates the Benders cuts and master problem uses them as a new inequality constraint which is added to the previous constraints. The iterative process will continue until upper and lower bounds of the objective function optimal values are close enough and a converged optimal solution is found. Benders decomposition based approach is able to provide a good framework to consider the non-convex feasible operation regions of cogeneration units efficiently. In this paper, a four-unit system with two cogeneration units and a five-unit system with three cogeneration units are analyzed to exhibit the effectiveness of the proposed approach. In all cases, the

  4. Economic feasibility of heat supply from nuclear power plants in the United States

    International Nuclear Information System (INIS)

    Roe, K.K.; Oliker, I.

    1987-01-01

    Nuclear energy is regarded as competitive for urban district heating applications. Hot water heat transoport systems of up to 50 miles are feasible for heat loads over 1500 MWt, and heat load density of over 130 MWt/mi 2 is most suitable for nuclear applications. An incremental approach and a nuclear plant design provision for future heat extraction are recommended. Nuclear district heating technology status is discussed, particularly turbine design. Results of a study for retrofitting a major existing nuclear power plant to cogeneration operation are presented. The study indicates that for transmission distances up to 20 miles it is economical to generate and transport between 600 and 1200 MWt of district heat (author)

  5. A method of determining the thermal power demand of buildings connected to the district heating system with usage of heat accumulation

    Directory of Open Access Journals (Sweden)

    Turski Michał

    2017-01-01

    Full Text Available The paper presents a new method of determining the thermal power demand of buildings connected to the district heating system, which included the actual heat demand and the possibility of balancing the thermal power using the thermal storage capacity of district heating network and internal heat capacity of buildings. Moreover, the analysis of the effect of incidence of external air temperature and duration of episodes with the lowest outdoor temperatures on the thermal power demand of district heating system was conducted.

  6. Solar power from the supermarket. Water heating, space heating and air conditioning with solar collectors

    Energy Technology Data Exchange (ETDEWEB)

    1976-08-01

    The different ways of utilizing solar energy are discussed. So far, top water heating is still the most practicable and most economical solution. Model houses with solar collectors, built by BBC and Philips, are dealt with in particular.

  7. Wood chip drying in connection with combined heat and power or solar energy in Finland

    Directory of Open Access Journals (Sweden)

    Rinne Samuli

    2014-01-01

    Full Text Available 20% of the Finnish district heating (DH power plant fuels are wood-based and the share is increasing. The wood fuel demand probably exceeds the potential supply in the future. The wood fuel drying with waste heat is one profitable opportunity to gain more wood fuel. If the drying energy can be produced with lower primary energy use than combusting the fuel directly, the drying potentially improves the system efficiency. In this study, the drying feasibility in the connection of a combined heat and power (CHP system, possibly with solar collectors, is calculated. The wood fuel heating can be increased profitably by 6%, using the heat from CHP for drying only when the marginal cost of the heat is low enough, i.e. the electricity price is high enough and there is free capacity after the DH demand. Although the drying is profitable, a larger heat storage can also increase the annual result similarly. The best investment choice depends on the plant properties. Here the optimal system enables 20% DH production cost savings. Solar heat may be profitable, when the solar heat has a 2–3% share of the annual heat demand. However, the dryer or larger storage tank are more profitable investments.

  8. Wind Turbines and Heat Pumps. Balancing wind power fluctuations using flexible demand

    International Nuclear Information System (INIS)

    Warmer, C.J.; Hommelberg, M.P.F.; Kamphuis, I.G.; Derszi, Z.; Kok, J.K.

    2007-01-01

    In order to overcome portfolio imbalance for traders of variable power from wind we have built an 'Imbalance Reduction System' (IRS) and performed a real-world field test with it, in which imbalance is minimized within a real-time electricity market portfolio, consisting of wind power and industrial and residential consumers and producers (Combined Heat and Power for district heating; residential heat pumps; industrial cold store; emergency generators). IRS uses the PowerMatcher concept, a coordination system for supply and demand of electricity in a which multi-agent system is combined with microeconomic principles. IRS appears to offer opportunities for embedding less predictable generators such as wind power more smoothly in the portfolio. We describe the context and operation of the Imbalance Reduction System and discuss a number of results from the performed field test. Also we introduce a business model for the balance responsible party, based on the e3-value method

  9. Fluidised bed combustion: a new route to power and heat from coal

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, H D [Bergbau-Forschung G.m.b.H., Essen (Germany, F.R.)

    1978-02-01

    The functioning of fluidized-bed firings and their advantages with regard to SO/sub 2/ emissions are described. The principle of design of a fluidized-bed boiler and a gas/steam turbine power plant with fluidized-bed firing under pressure is outlined. The application and their economics in heat and power generation and marketing potential of fluidized-bed firings and their economics in heat and power generation is pointed out. The construction of waste-fired incinerators has already become possible, but there is still a lot of development work to be done until fluidized-bed firings can be used in central heatings, combined-cycle power plants, and large power plants.

  10. Power generation and heating performances of integrated system of ammonia–water Kalina–Rankine cycle

    International Nuclear Information System (INIS)

    Zhang, Zhi; Guo, Zhanwei; Chen, Yaping; Wu, Jiafeng; Hua, Junye

    2015-01-01

    Highlights: • Integrated system of ammonia–water Kalina–Rankine cycle (AWKRC) is investigated. • Ammonia–water Rankine cycle is operated for cogenerating room heating-water in winter. • Kalina cycle with higher efficiency is operated for power generation in other seasons. • Power recovery efficiency accounts thermal efficiency and waste heat absorbing ratio. • Heating water with 70 °C and capacity of 55% total reclaimed heat load is cogenerated. - Abstract: An integrated system of ammonia–water Kalina–Rankine cycle (AWKRC) for power generation and heating is introduced. The Kalina cycle has large temperature difference during evaporation and small one during condensation therefore with high thermal efficiency for power generation, while the ammonia–water Rankine cycle has large temperature difference during condensation as well as evaporation, thus it can be adopted to generate heating-water as a by-product in winter. The integrated system is based on the Kalina cycle and converted to the Rankine cycle with a set of valves. The performances of the AWKRC system in different seasons with corresponding cycle loops were studied and analyzed. When the temperatures of waste heat and cooling water are 300 °C and 25 °C respectively, the thermal efficiency and power recovery efficiency of Kalina cycle are 20.9% and 17.4% respectively in the non-heating seasons, while these efficiencies of the ammonia–water Rankine cycle are 17.1% and 13.1% respectively with additional 55.3% heating recovery ratio or with comprehensive efficiency 23.7% higher than that of the Kalina cycle in heating season

  11. The development of a thermoelectric power generator dedicated to stove-fireplaces with heat accumulation systems

    International Nuclear Information System (INIS)

    Sornek, Krzysztof; Filipowicz, Mariusz; Rzepka, Kamila

    2016-01-01

    Highlights: • Application of thermoelectric generators in the stove-fireplace with accumulation. • Construction of the thermoelectric generator is limited by the heat accumulation. • Variants of the heat exchanger’s construction are discussed. • The control method is related on velocity of flue gas and water cooling. • The power limit of 30 W for self-sufficient operation is sufficient. - Abstract: A significant part of the world’s population (about 40%) cooks their meals and provides heating for their homes using wood-burning heating devices. Due to the relatively low cost of fuel and their aesthetic design, solid fuel stoves capable of heat accumulation are convenient and common. The use of dedicated small-scale power generators provides also additional benefits. This paper presents the results of a study conducted to verify the possibility of generating power using stove-fireplaces with heat accumulation systems. In such units, the temperature of the flue gas should be kept at a certain level for the purposes of storing heat, which results from certain limitations of the thermoelectric generators. To verify the possibility of applying thermoelectric modules in such heating devices, a dedicated system with thermoelectric generators was selected from among various microcogeneration systems and implemented. Three types of heat exchangers were studied and the most efficient unit was selected for further testing. Two types of generators, with maximum operating temperatures of 320 and 175 °C, were compared. Subsequently, the characteristics of the latter were determined. The conducted tests allowed to determine the performance and the total efficiency of the generators that were used. It has been demonstrated that the maximum power of the generator would not exceed ca. 30 W e and that there is no economic justification for such a device. However, providing a self-powered and self-sufficient operation of stove-fireplaces with heat accumulation systems

  12. High-power and steady-state operation of ICRF heating in the large helical device

    Energy Technology Data Exchange (ETDEWEB)

    Mutoh, T., E-mail: mutoh@nifs.ac.jp; Seki, T.; Saito, K.; Kasahara, H.; Seki, R.; Kamio, S.; Kumazawa, R.; Kubo, S.; Shimozuma, T.; Yoshimura, Y.; Igami, H.; Takahashi, H.; Ii, T.; Makino, R.; Nagaoka, K.; Nomura, G. [National Institute for Fusion Science, 322-6, Oroshi-cho, Toki, Gifu, 509-5292 (Japan); Shinya, T. [The University of Tokyo, Kashiwa 2777-8561 (Japan)

    2015-12-10

    Recent progress in an ion cyclotron range of frequencies (ICRF) heating system and experiment results in a Large Helical Device (LHD) are reported. Three kinds of ICRF antenna pairs were installed in the LHD, and the operation power regimes were extended up to 4.5 MW; also, the steady-state operation was extended for more than 45 min in LHD at a MW power level. We studied ICRF heating physics in heliotron configuration using a Hand Shake type (HAS) antenna, Field Aligned Impedance Transforming (FAIT) antenna, and Poloidal Array (PA) antenna, and established the optimum minority-ion heating scenario in an LHD. The FAIT antenna having a novel impedance transformer inside the vacuum chamber could reduce the VSWR and successfully injected a higher power to plasma. We tested the PA antennas completely removing the Faraday-shield pipes to avoid breakdown and to increase the plasma coupling. The heating performance was almost the same as other antennas; however, the heating efficiency was degraded when the gap between the antenna and plasma surface was large. Using these three kinds of antennas, ICRF heating could contribute to raising the plasma beta with the second- and third-harmonic cyclotron heating mode, and also to raising the ion temperature as discharge cleaning tools. In 2014, steady-state operation plasma with a line-averaged electron density of 1.2 × 10{sup 19} m{sup −3}, ion and electron temperature of 2 keV, and plasma sustainment time of 48 min was achieved with ICH and ECH heating power of 1.2 MW for majority helium with minority hydrogen. In 2015, the higher-power steady-state operation with a heating power of up to 3 MW was tested with higher density of 3 × 10{sup 19} m{sup −3}.

  13. More Wind Power Integration with Adjusted Energy Carriers for Space Heating in Northern China

    Directory of Open Access Journals (Sweden)

    Jianjun He

    2012-08-01

    Full Text Available In Northern China, due to the high penetration of coal-fired cogeneration facilities, which are generally equipped with extraction-condensing steam turbines, lots of wind power resources may be wasted during the heating season. In contrast, considerable coal is consumed in the power generation sector. In this article, firstly it is revealed that there exists a serious divergence in the ratio of electrical to thermal energy between end users’ demand and the cogenerations’ production during off-peak load at night, which may negate active power-balancing of the electric power grid. Secondly, with respect to this divergence only occurring during off-peak load at night, a temporary proposal is given so as to enable the integration of more wind power. The authors suggest that if the energy carrier for part of the end users’ space heating is switched from heating water to electricity (e.g., electric heat pumps (EHPs can provide space heating in the domestic sector, the ratio of electricity to heating water load should be adjusted to optimize the power dispatch between cogeneration units and wind turbines, resulting in fuel conservation. With this proposal, existing infrastructures are made full use of, and no additional ones are required. Finally a numerical simulation is performed in order to illustrate both the technical and economic feasibility of the aforementioned proposal, under ongoing infrastructures as well as electricity and space heating tariff conditions without changing participants’ benefits. The authors aim to persuade Chinese policy makers to enable EHPs to provide space heating to enable the integration of more wind power.

  14. Optimal economic dispatch of FC-CHP based heat and power micro-grids

    International Nuclear Information System (INIS)

    Nazari-Heris, Morteza; Abapour, Saeed; Mohammadi-Ivatloo, Behnam

    2017-01-01

    Highlights: • The multi objective economic/environmental heat and power MG dispatch is solved. • The heat and power MG include FC, CHP, boiler, storage system, and heat buffer tank. • Multi objective scheduling of heat and power MG is solved using ε-constraint method. • DR program is employed in the stochastic programming of heat and power MG dispatch. • The uncertainties for load demand and price signals are taken into account. - Abstract: Micro-grids (MGs) are introduced as a solution for distributed energy resource (DER) units and energy storage systems (ESSs) to participate in providing the required electricity demand of controllable and non-controllable loads. In this paper, the authors study the short-term scheduling of grid-connected industrial heat and power MG which contains a fuel cell (FC) unit, combined heat and power (CHP) generation units, power-only unit, boiler, battery storage system, and heat buffer tank. The paper is aimed to solve the multi-objective MG dispatch problem containing cost and emission minimization with the considerations of demand response program and uncertainties. A probabilistic framework based on a scenario method, which is considered for load demand and price signals, is employed to overcome the uncertainties in the optimal energy management of the MG. In order to reduce operational cost, time-of-use rates of demand response programs have been modeled, and the effects of such programs on the load profile have been discussed. To solve the multi-objective optimization problem, the ε-constraint method is used and a fuzzy satisfying approach has been employed to select the best compromise solution. Three cases are studied in this research to confirm the performance of the proposed method: islanded mode, grid-connected mode, and the impact of time of the use-demand response program on MG scheduling.

  15. Title Investigation of the influence of various factors on the power of heat exchange by radiation

    Directory of Open Access Journals (Sweden)

    Korolyov Alexander V.

    2017-04-01

    Full Text Available The issue of lack of knowledge of radiation heat transfer process has been repeatedly raised in various studies. Despite the fact that works on study of heat transfer by radiation covers a wide range of different industries, it should be noted the lack of materials on study of heat exchange processes by radiation in a core of a nuclear reactor. In this work, the fuel assemblies of the VVER-1000 reactor were used as the bodies under study. Aim: The aim of the research is to investigate the heat exchange process between heat transfer assemblies and to study of the effect of changing the distance between the fuel assemblies on their power taking into account the inter-radiating of assemblies. Materials and Methods: A general description of the process of heat transfer by radiation. A calculation study of the effect of geometric parameters on heat transfer in the close lattice of the reactor core is performed. The influence of heat transfer by radiation on the temperature change of the fuel assemblies surface of the VVER-1000 reactor at change in the cassette gap is studied. The change in the power of the fuel assemblies relative to the initial power with a change in the cassette gap was studied. Experimental measurements of the temperature at different distances from the radiation source were made with an obstacle in the path of radiation propagation in the form of glass and water of different levels. The heat radiation and convective heat transfer are calculated based on the obtained experimental data. The calculation of thermal radiation power and convective heat transfer based on the obtained experimental data is performed. Results: The calculation results show that in models that determine the temperature of the fuel assemblies in the core of the VVER-1000 reactor, the radiation heat transfer must be taken into account. In this case, the amount of transferred energy is the greater, the smaller the distance between objects. This is observed

  16. SOME FEATURES OF THE POWER SUPPLY OF RESIDENTIAL BUILDINGS DURING THE HEATING SEASON

    Directory of Open Access Journals (Sweden)

    S. N. Osipov

    2017-01-01

    Full Text Available A large proportion of consumption of different types of energy by the residential sector, especially in the heating period, makes the energy efficiency of buildings without considering the loss of fuel with a significant reduction in hourly load on the generators, especially at night, already insufficient for real energy savings. Therefore in Belarus, in order to attract the consumer, electricity tariff for heating at night hours (from 11 p.m. to 6.00 a.m. is three times cheaper than at any other time. Significant increase of the electricity consumption of at night could be achieved by using heat accumulators for heating and hot water supply to the residential sector. Particularly effective are water accumulators of heat and accumulators of underfloor heating that enable to use a coolant with a temperature of 40 оC and to increase the useful supply of heat. The use of heat accumulators for daily heating, ventilation and hot water supply of buildings significantly reduces the cost of creating the infrastructure of the territory under construction by eliminating the necessity of running the distribution network of heat or gas supply. The use of the heat accumulators is necessary due to the increase of the time-weighted average outdoor temperature. The mentioned increase in the City of Minsk in the heating season is of about 0.1 °C per year in average, and as for the last 20 years, the increase has led to a reduction of the required heat load on the premises by about 10 %. Research and project work on choosing the most effective options for the arrangement and use the heat accumulators in buildings of the various functions ought to be fulfilled in order to make the application of heat accumulators successful. In this respect civil and power engineers as well as operators should work together so to determine the chronological, technical and economic conditions of charging and use of heat accumulators.

  17. Sulfur Based Thermochemical Heat Storage for Baseload Concentrated Solar Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Bunsen [General Atomics, San Diego, CA (United States)

    2014-11-01

    This project investigates the engineering and economic feasibility of supplying baseload power using a concentrating solar power (CSP) plant integrated with sulfur based thermochemical heat storage. The technology stores high temperature solar heat in the chemical bonds of elemental sulfur. Energy is recovered as high temperature heat upon sulfur combustion. Extensive developmental and design work associated with sulfur dioxide (SO2) disproportionation and sulfuric acid (H2SO4) decomposition chemical reactions used in this technology had been carried out in the two completed phases of this project. The feasibility and economics of the proposed concept was demonstrated and determined.

  18. Testing for cross-subsidisation in the combined heat and power generation sector

    DEFF Research Database (Denmark)

    Amundsen, Eirik S; Andersen, Per; Jensen, Frank

    2011-01-01

    In this paper we examine cross-subsidisation among combined heat and power producers in Denmark.Information on stand-alone costs for heat generation allows us to empirically compare the Faulhaber tests,tests with an upper bound on stand-alone costs (the Palmer tests) and the fully distributed cos...... test (FDC). All tests indicate a substantial amount of cross-subsidisation from heat generation to power generation. It is shown that the FDC test is closer to that of the Faulhaber tests in its results than the Palmer tests. Thus as the Faulhaber tests are considered in the literature...

  19. Stochastic Programming for Fuel Supply Planning of Combined Heat and Power Plants

    DEFF Research Database (Denmark)

    Guericke, Daniela; Blanco, Ignacio; Morales González, Juan Miguel

    The consumption of biomass to produce power and heat has increased due to the carbon neutral policies. Combined heat and power (CHP) plants often combine biomass with other fuels, e.g., natural gas. The negotiation process for supply contracts involves many uncertainties due to the long planning...... horizon. The demand for biomass is uncertain, and heat demand and electricity prices vary during the planning period. We propose a method using stochastic optimization to support the biomass and natural gas supply planning for CHP plants including short-term decisions for optimal market participation....

  20. Thermoelectric automotive waste heat energy recovery using maximum power point tracking

    International Nuclear Information System (INIS)

    Yu Chuang; Chau, K.T.

    2009-01-01

    This paper proposes and implements a thermoelectric waste heat energy recovery system for internal combustion engine automobiles, including gasoline vehicles and hybrid electric vehicles. The key is to directly convert the heat energy from automotive waste heat to electrical energy using a thermoelectric generator, which is then regulated by a DC-DC Cuk converter to charge a battery using maximum power point tracking. Hence, the electrical power stored in the battery can be maximized. Both analysis and experimental results demonstrate that the proposed system can work well under different working conditions, and is promising for automotive industry.

  1. Universal Trade-Off between Power, Efficiency, and Constancy in Steady-State Heat Engines

    Science.gov (United States)

    Pietzonka, Patrick; Seifert, Udo

    2018-05-01

    Heat engines should ideally have large power output, operate close to Carnot efficiency and show constancy, i.e., exhibit only small fluctuations in this output. For steady-state heat engines, driven by a constant temperature difference between the two heat baths, we prove that out of these three requirements only two are compatible. Constancy enters quantitatively the conventional trade-off between power and efficiency. Thus, we rationalize and unify recent suggestions for overcoming this simple trade-off. Our universal bound is illustrated for a paradigmatic model of a quantum dot solar cell and for a Brownian gyrator delivering mechanical work against an external force.

  2. The power consumption of mural central heating boilers; La consommation electrique des chaudieres murales

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1997-10-01

    Two huge campaigns of measurements in the residential sector have revealed the unsuspected level of power consumption of heating and ventilation auxiliaries. It is important to know these levels in order to reduce them as they can significantly increase the energy bill of the lodging. This paper analyzes the case of mural central heating boilers with their auxiliaries: circulating pump of the heating loop and of the sanitary hot water production, ventilation systems, impact of the type of control system used (programmable clock, thermostat or none), annual and seasonal power consumption and the different solutions to reduce these over-consumptions. (J.S.)

  3. The ''Dolphin'' power laser installation for spherical thermonuclear target heating

    International Nuclear Information System (INIS)

    Basov, N.G.; Bykovskij, N.E.; Danilov, A.E.

    1978-01-01

    12-channel laser installation the ''Dolphin'' for thermonuclear target heating in the radiation spheric geometry has been developed to carry out series of physical investigations of laser-thermonuclear plasma system, optimization of target heating conditions and obtaining a comparatively large value of thermonuclear output in ratio to the energy of absorbed light radiation in the target. The description of installation main elements, consisting of the following components, is given: 1)neodymium laser with the maximum permissible radiation energy of 10kJ, with light pulse duration of 10 -10 /10 -9 c and radiation divergence of approximately 5x10 -4 rad; 2)vacuum chamber, where laser radiation interaction with plasma takes place; 3)diagnostic means of laser and plasma parameters and 4)focus system. The focus system provides a high degree of target spherical radiation symmetry at current maximum density on its surface of approximately 10 15 W/cm 2

  4. On introduction of artificial intelligence elements to heat power engineering

    Science.gov (United States)

    Dregalin, A. F.; Nazyrova, R. R.

    1993-10-01

    The basic problems of 'the thermodynamic intelligence' of personal computers have been outlined. The thermodynamic intellect of personal computers as a concept has been introduced to heat processes occurring in engines of flying vehicles. In particular, the thermodynamic intellect of computers is determined by the possibility of deriving formal relationships between thermodynamic functions. In chemical thermodynamics, a concept of a characteristic function has been introduced.

  5. Improvement of Candu-1000 MW(e) power cycle by moderator heat recovery

    International Nuclear Information System (INIS)

    Fath, H.E.S.

    1988-01-01

    Four different moderator heat recovery circuits are proposed for CANDU-1000 MW(e) reactors. The proposed circuits utilize all, or part, of the 155 MW(th) moderator heat load (at 70 0 C moderator outlet temperature from calandria) to the first stage of the feed water heating system. An economics study was carried out and indicated that the direct circulation of feed water through the moderator heat exchanger (with full heat recovery) is the most economical scheme. For this scheme the saved steam from the turbine extraction was found to produce additional electric power of 8 MW(e). This additional power represents a 0.7% increase in the plants nominal electric output. The outstanding features and advantages of the selected scheme are also presented. (author)

  6. Power density of piezoelectric transformers improved using a contact heat transfer structure.

    Science.gov (United States)

    Shao, Wei Wei; Chen, Li Juan; Pan, Cheng Liang; Liu, Yong Bin; Feng, Zhi Hua

    2012-01-01

    Based on contact heat transfer, a novel method to increase power density of piezoelectric transformers is proposed. A heat transfer structure is realized by directly attaching a dissipater to the piezoelectric transformer plate. By maintaining the vibration mode of the transformer and limiting additional energy losses from the contact interface, an appropriate design can improve power density of the transformer on a large scale, resulting from effective suppression of its working temperature rise. A prototype device was fabricated from a rectangular piezoelectric transformer, a copper heat transfer sheet, a thermal grease insulation pad, and an aluminum heat radiator. The experimental results show the transformer maintains a maximum power density of 135 W/cm(3) and an efficiency of 90.8% with a temperature rise of less than 10 °C after more than 36 h, without notable changes in performance. © 2012 IEEE

  7. The simulation study on the Nuclear Heating Reactor's power auto-control system

    International Nuclear Information System (INIS)

    Yang Zhijun; Liu Longzhi; Hu Guifen

    2000-01-01

    The power automatic control system on nuclear heating reactor (NHR) is a multi-input and multi-output non-linear system. The power automatic control system on NHR is studied by modern control theory. Through the simulation experiments, it is clear that adopting μ outer-loop and LQR inner-loop feedback, the best control results are obtained

  8. Integrated three-dimensional module heat exchanger for power electronics cooling

    Science.gov (United States)

    Bennion, Kevin; Lustbader, Jason

    2013-09-24

    Embodiments discussed herein are directed to a power semiconductor packaging that removes heat from a semiconductor package through one or more cooling zones that are located in a laterally oriented position with respect to the semiconductor package. Additional embodiments are directed to circuit elements that are constructed from one or more modular power semiconductor packages.

  9. Apparatus and method for heat-run test on high-power PWM ...

    Indian Academy of Sciences (India)

    Due to its bi-directional power flow capability, this is used in a ..... generation, and selection of controller parameters for the voltage and current loops is presented ..... For example, the total power consumed for heat-run test on converters at a.

  10. Analytical analysis of heat transfer and pumping power of laminar nanofluid developing flow in microchannels

    International Nuclear Information System (INIS)

    Mital, Manu

    2013-01-01

    Thermal management issues are limiting barriers to high density electronics packaging and miniaturization. Liquid cooling using micro and mini channels is an attractive alternative to large and bulky aluminum or copper heat sinks. These channels can be integrated directly into a chip or a heat spreader, and cooling can be further enhanced using nanofluids (liquid solutions with dispersed nanometer-sized particles) due to their enhanced heat transfer effects reported in literature. The goals of this study are to evaluate heat transfer improvement of a nanofluid heat sink with developing laminar flow forced convection, taking into account the pumping power penalty. The phrase heat transfer enhancement ratio (HTR) is used to denote the ratio of average heat transfer coefficient of nanofluid to water at the same pumping power. The proposed model uses semi-empirical correlations to calculate nanofluid thermophysical properties. The predictions of the model are found to be in good agreement with experimental studies. The validated model is used to identify important design variables (Reynolds number, volume fraction and particle size) related to thermal and flow characteristics of the microchannel heat sink with nanofluids. Statistical analysis of the model showed that the volume fraction is the most significant factor impacting the HTR, followed by the particle diameter. The impact of the Reynolds number and other interaction terms is relatively weak. The HTR is maximized at smallest possible particle diameter (since smaller particles improve heat transfer but do not impact pumping power). Then, for a given Reynolds number, an optimal value of volume fraction can be obtained to maximize HTR. The overall aim is to present results that would be useful for understanding and optimal design of microchannel heat sinks with nanofluid flow. - Highlights: ► Validated model is used to investigate heat transfer and pumping power in nanofluids. ► Particles improve heat transfer

  11. Study on heat pipe assisted thermoelectric power generation system from exhaust gas

    Science.gov (United States)

    Chi, Ri-Guang; Park, Jong-Chan; Rhi, Seok-Ho; Lee, Kye-Bock

    2017-11-01

    Currently, most fuel consumed by vehicles is released to the environment as thermal energy through the exhaust pipe. Environmentally friendly vehicle technology needs new methods to increase the recycling efficiency of waste exhaust thermal energy. The present study investigated how to improve the maximum power output of a TEG (Thermoelectric generator) system assisted with a heat pipe. Conventionally, the driving energy efficiency of an internal combustion engine is approximately less than 35%. TEG with Seebeck elements is a new idea for recycling waste exhaust heat energy. The TEG system can efficiently utilize low temperature waste heat, such as industrial waste heat and solar energy. In addition, the heat pipe can transfer heat from the automobile's exhaust gas to a TEG. To improve the efficiency of the thermal power generation system with a heat pipe, effects of various parameters, such as inclination angle, charged amount of the heat pipe, condenser temperature, and size of the TEM (thermoelectric element), were investigated. Experimental studies, CFD simulation, and the theoretical approach to thermoelectric modules were carried out, and the TEG system with heat pipe (15-20% charged, 20°-30° inclined configuration) showed the best performance.

  12. Preliminary Study of Printed Circuit Heat Exchanger (PCHE) for various power conversion systems for SMART

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Jinsu; Baik, Seungjoon; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of)

    2016-10-15

    The steam-Rankine cycle was the most widely used power conversion system for a nuclear power plant. The size of the heat exchanger is important for the modulation. Such a challenge was conducted by Kang et al. They change the steam generator type for the SMART from helical type heat exchanger to Printed Circuit Heat Exchanger (PCHE). Recently, there has been a growing interest in the supercritical carbon dioxide (S-CO{sub 2}) Brayton cycle as the most promising power conversion system. The reason is high efficiency with simple layout and compact power plant due to small turbomachinery and compact heat exchanger technology. That is why the SCO{sub 2} Brayton cycle can enhance the existing advantages of Small Modular Reactor (SMR) like SMART, such as reduction in size, capital cost, and construction period. Thermal hydraulic and geometric parameters of a PCHE for the S-CO{sub 2} power cycle coupled to SMART. The results show that the water - CO{sub 2} printed circuit heat exchanger size is smaller than printed circuit steam generator for the superheated steam Rankine cycle. This results show the potential benefit of using the S-CO-2 Brayton power cycle to a water-cooled small modular reactor.

  13. Study of a molten carbonate fuel cell combined heat, hydrogen and power system: Energy analysis

    International Nuclear Information System (INIS)

    Agll, Abdulhakim Amer A.; Hamad, Yousif M.; Hamad, Tarek A.; Thomas, Mathew; Bapat, Sushrut; Martin, Kevin B.; Sheffield, John W.

    2013-01-01

    Countries around the world are trying to use alternative fuels and renewable energy to reduce the energy consumption and greenhouse gas emissions. Biogas contains methane is considered a potential source of clean renewable energy. This paper discusses the design of a combined heat, hydrogen and power system, which generated by methane with use of Fuelcell, for the campus of Missouri University of Science and Technology located in Rolla, Missouri, USA. An energy flow and resource availability study was performed to identify sustainable type and source of feedstock needed to run the Fuelcell at its maximum capacity. FuelCell Energy's DFC1500 unit (a molten carbonate Fuelcell) was selected as the Fuelcell for the tri-generation (heat, hydrogen and electric power) system. This tri-generation system provides electric power to the campus, thermal energy for heating the anaerobic digester, and hydrogen for transportation, backup power and other applications on the campus. In conclusion, the combined heat, hydrogen and power system reduces fossil fuel usage, and greenhouse gas emissions at the university campus. -- Highlights: • Combined heat, hydrogen and power (CHHP) using a molten carbonate fuel cell. • Energy saving and alternative fuel of the products are determined. • Energy saving is increased when CHHP technology is implemented. • CHHP system reduces the greenhouse gas emissions and fuel consumption

  14. Performance of double source boiler with coal-fired and solar power tower heat for supercritical power generating unit

    International Nuclear Information System (INIS)

    Zhang, Maolong; Du, Xiaoze; Pang, Liping; Xu, Chao; Yang, Lijun

    2016-01-01

    An approach of high-efficiency utilization of solar energy was proposed, by which the high concentrated heat received by the solar tower was integrated to the supercritical coal-fired boiler. Two schemes that solar energy was used to heat superheat steam or subcooled feed water were presented. The thermodynamic and heat transfer models were established. For a practical 660 MW supercritical power generating unit, the standard coal consumption of power generation could be decreased by more than 17 g/kWh by such double source boiler. The drawbacks of both schemes were found and then were amended by adding a flue gas bypass to the boiler. It also can be concluded that the maximum solar contribution of two schemes for the gross power generation are 6.11% and 4.90%, respectively. The solar power efficiency of the re-modified designs were demonstrated be superior to that of PS10. In terms of turbine efficiency, the comparisons with Solar Two plant having similar initial temperature found that the efficiency of Scheme I was 5.25% higher than that of Solar Two while the advantage of Scheme II was existing either. Additionally, in two schemes with flue bypass when the medium was extracted, the thermal efficiency of boiler could be improved as well. - Highlights: • High concentrated solar tower heat is integrated to the supercritical coal-fired boiler. • The double source boiler can use solar energy to heat superheat steam or subcooled feed water. • Power generating coal consumption can be reduced by more than 17 g/kWh by the double source boiler. • The solar contribution of double source boiler for the gross power generation can be as high as 6.11%.

  15. Performance of RF power and phase control on JT-60 LHRF heating system

    International Nuclear Information System (INIS)

    Fujii, T.; Ikeda, Y.; Imai, T.; Honda, M.; Kiyono, K.; Maebara, S.; Saigusa, M.; Sakamoto, K.; Sawahata, M.; Seki, M.

    1987-01-01

    The performance of RF power and phase control on the JT-60 LHRFD heating system are presented. The JT-60 LHRF heating system has three units of huge RF source with a total output of 24 MW, each unit consisting of eight amplifier chains. A high power klystron generating 1 MW for 10 s at 2 GHz is used in each chain. Automatic gain control is employed to regulate the output power not only against gain fluctuations in the chain but also against the unstable plasma load without any output circulator for the klystron

  16. Waste heat recovery options in a large gas-turbine combined power plant

    Science.gov (United States)

    Upathumchard, Ularee

    This study focuses on power plant heat loss and how to utilize the waste heat in energy recovery systems in order to increase the overall power plant efficiency. The case study of this research is a 700-MW natural gas combined cycle power plant, located in a suburban area of Thailand. An analysis of the heat loss of the combustion process, power generation process, lubrication system, and cooling system has been conducted to evaluate waste heat recovery options. The design of the waste heat recovery options depends to the amount of heat loss from each system and its temperature. Feasible waste heat sources are combustion turbine (CT) room ventilation air and lubrication oil return from the power plant. The following options are being considered in this research: absorption chillers for cooling with working fluids Ammonia-Water and Water-Lithium Bromide (in comparison) and Organic Rankine Cycle (ORC) with working fluids R134a and R245fa. The absorption cycles are modeled in three different stages; single-effect, double-effect and half-effect. ORC models used are simple ORC as a baseline, ORC with internal regenerator, ORC two-phase flash expansion ORC and ORC with multiple heat sources. Thermodynamic models are generated and each system is simulated using Engineering Equation Solver (EES) to define the most suitable waste heat recovery options for the power plant. The result will be synthesized and evaluated with respect to exergy utilization efficiency referred as the Second Law effectiveness and net output capacity. Results of the models give recommendation to install a baseline ORC of R134a and a double-effect water-lithium bromide absorption chiller, driven by ventilation air from combustion turbine compartment. The two technologies yield reasonable economic payback periods of 4.6 years and 0.7 years, respectively. The fact that this selected power plant is in its early stage of operation allows both models to economically and effectively perform waste heat

  17. The role of combined heat and power (CHP) in energy and climate policy

    International Nuclear Information System (INIS)

    Conrad, F.

    1993-03-01

    In the energy- and environment context CHP is said to be especially energy saving and climate preserving. This report shows that from the standpoint of energy economics as well as under technical aspects this judgement holds true only under special conditions. Depending on the technical parameters, the concrete circumstances of operation and the characteristics of the power plants and heating systems compared to CHP-plants the range of realistic energy savings turns out to be very large. Related overstimations are to a good extend caused by the traditional practice of granting the energetic advantage of CHP exclusively to the district heating. If this advantage is credited to heat and power as equal shares space heating with cogenerated power of 80% efficiency reveals to be very energy conserving. The uno actu utilization of cogenerated heat and power, for the same purpose could facilitate the expansion of CHP, since the problems related to the feeding of cogenerated power into the grid for general purposes would disappear. The second main issue of this report concerns the abatement of CO 2 -emissions with the aid of CHP. Fuelled with natural gas, CHP-plants are attractive instruments for climate policy. This is especially true if CHP is compared to old coal-based power plants and oil-fuelled old heating systems. In the FRG, however, hard coal, and not natural gas, will be the main fuel for future CHP, lowering its CO 2 -advantage considerably. On the other hand high efficient combi-power plants (gas turbine plus condensing turbine) and gas heating systems have to be included in the comparative analyse. Compared to these advanced systems the CO 2 -characteristics of CHP are inferior. Moreover, the specific CO 2 -advantage of natural gas is better used by such modern mono systems rather than CHP-plants. (orig.) [de

  18. Increased power to heat ratio of small scale CHP plants using biomass fuels and natural gas

    International Nuclear Information System (INIS)

    Savola, Tuula; Fogelholm, Carl-Johan

    2006-01-01

    In this paper, we present a systematic study of process changes for increased power production in 1-20 MW e combined heat and power (CHP) plants. The changes are simulated, and their economic feasibility evaluated by using existing small scale CHP case plants. Increasing power production in decentralised CHP plants that operate according to a certain heat demand could reduce the fuel consumption and CO 2 emissions per power unit produced and improve the feasibility of CHP plant investments. The CHP plant process changes were simulated under design and off design conditions and an analysis of power and heat production, investment costs and CO 2 emissions was performed over the whole annual heat demand. The results show that using biomass fuels, there are profitable possibilities to increase the current power to heat ratios, 0.23-0.48, of the small scale CHP plants up to 0.26-0.56, depending on the size of the plant. The profitable changes were a two stage district heat exchanger and the addition of a steam reheater and a feed water preheater. If natural gas is used as an additional fuel, the power to heat ratio may be increased up to 0.35-0.65 by integrating a gas engine into the process. If the CO 2 savings from the changes are also taken into account, the economic feasibility of the changes increases. The results of this work offer useful performance simulation and investment cost knowledge for the development of more efficient and economically feasible small scale CHP processes

  19. Exergetic life cycle assessment of cement production process with waste heat power generation

    International Nuclear Information System (INIS)

    Sui, Xiuwen; Zhang, Yun; Shao, Shuai; Zhang, Shushen

    2014-01-01

    Highlights: • Exergetic life cycle assessment was performed for the cement production process. • Each system’s efficiency before and after waste heat power generation was analyzed. • The waste heat power generation improved the efficiency of each production system. • It provided technical support for the implementation of energy-saving schemes. - Abstract: The cement industry is an industry that consumes a considerable quantity of resources and energy and has a very large influence on the efficient use of global resources and energy. In this study, exergetic life cycle assessment is performed for the cement production process, and the energy efficiency and exergy efficiency of each system before and after waste heat power generation is investigated. The study indicates that, before carrying out a waste heat power generation project, the objective energy efficiencies of the raw material preparation system, pulverized coal preparation system and rotary kiln system are 39.4%, 10.8% and 50.2%, respectively, and the objective exergy efficiencies are 4.5%, 1.4% and 33.7%, respectively; after carrying out a waste heat power generation project, the objective energy efficiencies are 45.8%, 15.5% and 55.1%, respectively, and the objective exergy efficiencies are 7.8%, 2.8% and 38.1%, respectively. The waste heat power generation project can recover 3.7% of the total input exergy of a rotary kiln system and improve the objective exergy efficiencies of the above three systems. The study can identify degree of resource and energy utilization and the energy-saving effect of a waste heat power generation project on each system, and provide technical support for managers in the implementation of energy-saving schemes

  20. Optimization of operation for combined heat and power plants - CHP plants - with heat accumulators using a MILP formulation

    Energy Technology Data Exchange (ETDEWEB)

    Grue, Jeppe; Bach, Inger [Aalborg Univ. (Denmark). Inst. of Energy Technology]. E-mails: jeg@iet.auc.dk; ib@iet.auc.dk

    2000-07-01

    The power generation system in Denmark is extensively based on small combined heat and power plants (CHP plants), producing both electricity and district heating. This project deals with smaller plants spread throughout the country. Often a heat accumulator is used to enable electricity production, even when the heat demand is low. This system forms a very complex problem, both for sizing, designing and operation of CHP plants. The objective of the work is the development of a tool for optimisation of the operation of CHP plants, and to even considering the design of the plant. The problem is formulated as a MILP-problem. An actual case is being tested, involving CHP producing units to cover the demand. The results from this project show that it is of major importance to consider the operation of the plant in detail already in the design phase. It is of major importance to consider the optimisation of the plant operation, even at the design stage, as it may cause the contribution margin to rise significantly, if the plant is designed on the basis of a de-tailed knowledge of the expected operation. (author)

  1. Estimation and harvesting of human heat power for wearable electronic devices

    International Nuclear Information System (INIS)

    Dziurdzia, P; Brzozowski, I; Bratek, P; Gelmuda, W; Kos, A

    2016-01-01

    The paper deals with the issue of self-powered wearable electronic devices that are capable of harvesting free available energy dissipated by the user in the form of human heat. The free energy source is intended to be used as a secondary power source supporting primary battery in a sensor bracelet. The main scope of the article is a presentation of the concept for a measuring setup used to quantitative estimation of heat power sources in different locations over the human body area. The crucial role in the measurements of the human heat plays a thermoelectric module working in the open circuit mode. The results obtained during practical tests are confronted with the requirements of the dedicated thermoelectric generator. A prototype design of a human warmth energy harvester with an ultra-low power DC-DC converter based on the LTC3108 circuit is analysed

  2. Heat rate curve approximation for power plants without data measuring devices

    Energy Technology Data Exchange (ETDEWEB)

    Poullikkas, Andreas [Electricity Authority of Cyprus, P.O. Box 24506, 1399 Nicosia (CY

    2012-07-01

    In this work, a numerical method, based on the one-dimensional finite difference technique, is proposed for the approximation of the heat rate curve, which can be applied for power plants in which no data acquisition is available. Unlike other methods in which three or more data points are required for the approximation of the heat rate curve, the proposed method can be applied when the heat rate curve data is available only at the maximum and minimum operating capacities of the power plant. The method is applied on a given power system, in which we calculate the electricity cost using the CAPSE (computer aided power economics) algorithm. Comparisons are made when the least squares method is used. The results indicate that the proposed method give accurate results.

  3. Optimization of solar-powered Stirling heat engine with finite-time thermodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Yaqi, Li [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Xi' an Research Institute of Hi-Tech, Xi' an, Shaanxi 710025 (China); Yaling, He; Weiwei, Wang [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China)

    2011-01-15

    A mathematical model for the overall thermal efficiency of the solar-powered high temperature differential dish-Stirling engine with finite-rate heat transfer, regenerative heat losses, conductive thermal bridging losses and finite regeneration processes time is developed. The model takes into consideration the effect of the absorber temperature and the concentrating ratio on the thermal efficiency; radiation and convection heat transfer between the absorber and the working fluid as well as convection heat transfer between the heat sink and the working fluid. The results show that the optimized absorber temperature and concentrating ratio are at about 1100 K and 1300, respectively. The thermal efficiency at optimized condition is about 34%, which is not far away from the corresponding Carnot efficiency at about 50%. Hence, the present analysis provides a new theoretical guidance for designing dish collectors and operating the Stirling heat engine system. (author)

  4. Heat management of electric-powered vehicles; Thermomanagement von Elektro-Fahrzeugen

    Energy Technology Data Exchange (ETDEWEB)

    Renner, Markus; Koppe, Theresia [Webasto AG, Stockdorf (Germany)

    2010-07-01

    In contrast to a driving operation with combustion engine has in the purely electrical driving conditions only a fraction of the heat losses available from the power train components required for interior heating. Already at an ambient temperature of +10 C additional heating action is needed to prevent condensation on the vehicle windscreen and for a comfortable interior climate. An additional electrical heater strains the resource Battery and thus reduces the driving range for the electric drive depending on the driving cycle and environmental conditions up to 50%. A solution to this dilemma is a burner heating system with a neutral emission combustion process, uses the highest efficiency to direct the required heat energy to heat the vehicle. (orig.)

  5. Smart Heat and Power : Utilizing the Flexibility of Micro Cogeneration

    NARCIS (Netherlands)

    Houwing, M.

    2010-01-01

    Distributed generation (DG) contributes to a more sustainable electricity supply. Large-scale adoption of DG will bring radical changes to the traditional model of generation and supply as well as to the business model of the power industry. Furthermore, with innovations in information and

  6. Resistive vs. total power depositions by Alfven modes in pre-heated low aspect ratio tokamaks

    International Nuclear Information System (INIS)

    Cuperman, S.; Bruma, C.; Komoshvili, K.

    2004-01-01

    The power deposition of fast waves launched by a LFS located antenna in a pre-heated, strongly non-uniform low aspect ratio tokamak (START) is investigated. The rigorous computational results indicate a total power deposition by far larger than that predicted for Alfven continuum eigenmodes in cylindrical plasmas. For toroidal wave numbers |N| > 1, the resistive and total power depositions are almost equal. (author)

  7. Optimum power yield for bio fuel fired combined heat and power plants

    Energy Technology Data Exchange (ETDEWEB)

    Broden, Henrik; Nystroem, Olle; Joensson, Mikael

    2012-05-15

    Plant owners, suppliers, research institutions, industry representatives and (supporting) authorities are continuing to question the viability of what can be expected by increasing the steam data and the efficiency of cogeneration plants. In recent years, the overall conditions for investment in CHP have changed. Today, there is access to new materials that allow for more advanced steam data while maintaining availability. Although the financial environment with rising prices of electricity, heating and fuel along with the introduction of energy certificates and the interest in broadening the base of fuel has changed the situation. At the same time as the increased interest in renewable energy production creates competition among energy enterprises to find suppliers, increased prices for materials and labor costs have also resulted in increased investment and maintenance costs. Research on advanced steam data for biomass-fired power cogeneration plants has mainly emphasized on technical aspects of material selection and corrosion mechanisms based on performance at 100 % load looking at single years. Reporting has rarely been dealing with the overall economic perspective based on profitability of the CHP installations throughout their entire depreciation period. In the present report studies have been performed on how the choice of steam data affects the performance and economy in biomass-fired cogeneration plants with boilers of drum type and capacities at 30, 80 and 160 MWth with varied steam data and different feed water system configurations. Profitability is assessed on the basis of internal rate of return (IRR) throughout the amortization period of the plants. In addition, sensitivity analyses based on the most essential parameters have been carried out. The target group for the project is plant owners, contractors, research institutions, industry representatives, (supporting) authorities and others who are faced with concerns regarding the viability of what

  8. Thermodynamic evaluation of CHP (combined heat and power) plants integrated with installations of coal gasification

    International Nuclear Information System (INIS)

    Ziębik, Andrzej; Malik, Tomasz; Liszka, Marcin

    2015-01-01

    Integration of a CHP steam plant with an installation of coal gasification and gas turbine leads to an IGCC-CHP (integrated gasification combined cycle-combined heat and power). Two installations of coal gasification have been analyzed, i.e. pressurized entrained flow gasifier – case 1 and pressurized fluidized bed gasifier with CO_2 recirculation – case 2. Basing on the results of mathematical modelling of an IGCC-CHP plant, the algorithms of calculating typical energy indices have been derived. The following energy indices are considered, i.e. coefficient of heat performance and relative savings of chemical energy of fuels. The results of coefficients of heat performance are contained between 1.87 and 2.37. Values exceeding 1 are thermodynamically justified because the idea of cogeneration of heat and electricity based on combining cycles of the heat engine and heat pump the efficiency of which exceeds 1. Higher values concerning waste heat replace more thermodynamically effective sources of heat in CHP plants. Relative savings of the chemical energy of fuels are similar in both cases of IGCC-CHP plants and are contained between the lower value of the CHP (combined heat and power) plants fuelled with coal and higher value of CHP plants fired with natural gas. - Highlights: • Energy savings of fuel is an adequate measure of cogeneration. • Relative energy savings of IGCC-CHP is near the result of a gas and steam CHP. • COHP (coefficient of heat performance) can help to divide fuel between heat fluxes. • Higher values of COHP in the case of waste heat recovery result from the lower thermal parameters.

  9. A thermoelectric generator using loop heat pipe and design match for maximum-power generation

    KAUST Repository

    Huang, Bin-Juine

    2015-09-05

    The present study focuses on the thermoelectric generator (TEG) using loop heat pipe (LHP) and design match for maximum-power generation. The TEG uses loop heat pipe, a passive cooling device, to dissipate heat without consuming power and free of noise. The experiments for a TEG with 4W rated power show that the LHP performs very well with overall thermal resistance 0.35 K W-1, from the cold side of TEG module to the ambient. The LHP is able to dissipate heat up to 110W and is maintenance free. The TEG design match for maximum-power generation, called “near maximum-power point operation (nMPPO)”, is studied to eliminate the MPPT (maximum-power point tracking controller). nMPPO is simply a system design which properly matches the output voltage of TEG with the battery. It is experimentally shown that TEG using design match for maximum-power generation (nMPPO) performs better than TEG with MPPT.

  10. Simulation of D and E region high-power microwave heating with HF ionospheric modification experiments

    International Nuclear Information System (INIS)

    Meltz, G.; Rush, C.M.; Violette, E.J.

    1981-01-01

    The microwave power beam from a Solar Power Satellite (SPS) is sufficiently intense to cause large changes in the properties of the lower ionosphere by ohmic heating of the plasma. Power is absorbed from the beam at a rate that is proportional to the ratio of the flux s and the square of an effective frequency f/sub e/. Throughout most of the lower ionosphere f/sub e/ = f -+ f/sub L/, where f is the wave frequency and f/sub L is a reduced electron gyrofrequency. It follows that SPS equivalent heating can be simulated at much lower power fluxes with HF radio waves. A detailed examination of the frequency scaling, based on fluid and kinetic theory estimates of the change in electron temperature and density, shows that the high-power HF facility at Platteville, CO, can simulate or exceed the ohmic effects of the SPS beam up to 90 km. This paper describes the results of a series of 5.2 and 9.9 MHz underdense heating experiments undertaken to study the effect of high-power microwaves on the lower ionosphere. A pulsed ionosonde probe, located nearly below the most intense portion of the high-power beam, was used to observe the changes in the D and lower E region. Both phase and amplitude measurements were recorded during CW and intermittent heating

  11. Thulium heat source for high-endurance and high-energy density power systems

    International Nuclear Information System (INIS)

    Walter, C.E.; Kammeraad, J.E.; Van Konynenburg, R.; VanSant, J.H.

    1991-05-01

    We are studying the performance characteristics of radioisotope heat source designs for high-endurance and high-energy-density power systems that use thulium-170. Heat sources in the power range of 5--50 kW th coupled with a power conversion efficiency of ∼30%, can easily satisfy current missions for autonomous underwater vehicles. New naval missions will be possible because thulium isotope power systems have a factor of one-to-two hundred higher endurance and energy density than chemical and electrochemical systems. Thulium-170 also has several other attractive features, including the fact that it decays to stable ytterbium-170 with a half-life of four months. For terrestrial applications, refueling on that time scale should be acceptable in view of the advantage of its benign decay. The heat source designs we are studying account for the requirements of isotope production, shielding, and integration with power conversion components. These requirements are driven by environmental and safety considerations. Thulium is present in the form of thin refractory thulia disks that allow power conversion at high peak temperature. We give estimates of power system state points, performance, mass, and volume characteristics. Monte Carlo radiation analysis provides a detailed assessment of shield requirements and heat transfer under normal and distressed conditions is also considered. 11 refs., 7 figs., 4 tabs

  12. A new multi-objective reserve constrained combined heat and power dynamic economic emission dispatch

    International Nuclear Information System (INIS)

    Niknam, Taher; Azizipanah-Abarghooee, Rasoul; Roosta, Alireza; Amiri, Babak

    2012-01-01

    Combined heat and power units are playing an ever increasing role in conventional power stations due to advantages such as reduced emissions and operational cost savings. This paper investigates a more practical formulation of the complex non-convex, non-smooth and non-linear multi-objective dynamic economic emission dispatch that incorporates combined heat and power units. Integrating these types of units, and their power ramp constraints, require an efficient tool to cope with the joint characteristics of power and heat. Unlike previous approaches, the spinning reserve requirements of this system are clearly formulated in the problem. In this way, a new multi-objective optimisation based on an enhanced firefly algorithm is proposed to achieve a set of non-dominated (Pareto-optimal) solutions. A new tuning parameter based on a chaotic mechanism and novel self adaptive probabilistic mutation strategies are used to improve the overall performance of the algorithm. The numerical results demonstrate how the proposed framework was applied in real time studies. -- Highlights: ► Investigate a practical formulation of the DEED (Dynamic Economic Emission Dispatch). ► Consider combined heat and power units. ► Consider power ramp constraints. ► Consider the system spinning reserve requirements. ► Present a new multi-objective optimization firefly.

  13. Feedback control of plasma density and heating power for steady state operation in LHD

    Energy Technology Data Exchange (ETDEWEB)

    Kamio, Shuji, E-mail: kamio@nifs.ac.jp; Kasahara, Hiroshi; Seki, Tetsuo; Saito, Kenji; Seki, Ryosuke; Nomura, Goro; Mutoh, Takashi

    2015-12-15

    Highlights: • We upgraded a control system for steady state operation in LHD. • This system contains gas fueling system and ICRF power control system. • Automatic power boost system is also attached for stable operation. • As a result, we achieved the long pulse up to 48 min in the electron density of more than 1 × 10{sup 19} m{sup −3}. - Abstract: For steady state operation, the feedback control of plasma density and heating power system was developed in the Large Helical Device (LHD). In order to achieve a record of the long pulse discharge, stable plasma density and heating power are needed. This system contains the radio frequency (RF) heating power control, interlocks, gas fueling, automatic RF phase control, ion cyclotron range of frequency (ICRF) antenna position control, and graphical user interface (GUI). Using the density control system, the electron density was controlled to the target density and using the RF heating power control system, the RF power injection could be stable. As a result of using this system, we achieved the long pulse up to 48 min in the electron density of more than 1 × 10{sup 19} m{sup −3}. Further, the ICRF hardware experienced no critical accidents during the 17th LHD experiment campaign in 2013.

  14. Active Control of Power Exhaust in Strongly Heated ASDEX Upgrade Plasmas

    Science.gov (United States)

    Dux, Ralph; Kallenbach, Arne; Bernert, Matthias; Eich, Thomas; Fuchs, Christoph; Giannone, Louis; Herrmann, Albrecht; Schweinzer, Josef; Treutterer, Wolfgang

    2012-10-01

    Due to the absence of carbon as an intrinsic low-Z radiator, and tight limits for the acceptable power load on the divertor target, ITER will rely on impurity seeding for radiative power dissipation and for generation of partial detachment. The injection of more than one radiating species is required to optimise the power removal in the main plasma and in the divertor region, i.e. a low-Z species for radiation in the divertor and a medium-Z species for radiation in the outer core plasma. In ASDEX Upgrade, a set of robust sensors, which is suitable to feedback control the radiated power in the main chamber and the divertor as well as the electron temperature at the target, has been developed. Different feedback schemes were applied in H-mode discharges with a maximum heating power of up to 23,W, i.e. at ITER values of P/R (power per major radius) to control all combinations of power flux into the divertor region, power flux onto the target or electron temperature at the target through injection of nitrogen as the divertor radiator and argon as the main chamber radiator. Even at the highest heating powers the peak heat flux density at the target is kept at benign values. The control schemes and the plasma behaviour in these discharges will be discussed.

  15. High power plasma heating experiments on the Proto-MPEX facility

    Science.gov (United States)

    Bigelow, T. S.; Beers, C. J.; Biewer, T. M.; Caneses, J. F.; Caughman, J. B. O.; Diem, S. J.; Goulding, R. H.; Green, D. L.; Kafle, N.; Rapp, J.; Showers, M. A.

    2017-10-01

    Work is underway to maximize the power delivered to the plasma that is available from heating sources installed on the Prototype Materials Plasma Exposure eXperiment (Proto-MPEX) at ORNL. Proto-MPEX is a linear device that has a >100 kW, 13.56 MHz helicon plasma generator available and is intended for material sample exposure to plasmas. Additional plasma heating systems include a 10 kW 18 GHz electron cyclotron heating (ECH) system, a 25 kW 8 MHz ion cyclotron heating ICH system, and a 200 kW 28 GHz electron Bernstein wave (EBW) and ECH system. Most of the heating systems have relatively good power transmission efficiency, however, the 28 GHz EBW system has a lower efficiency owing to stringent requirements on the microwave launch characteristics for EBW coupling combined with the lower output mode purity of the early-model gyrotron in use and its compact mode converter system. A goal for the Proto-MPEX is to have a combined heating power of 200 kW injected into the plasma. Infrared emission diagnostics of the target plate combined with Thomson Scattering, Langmuir probe, and energy analyzer measurements near the target are utilized to characterize the plasmas and coupling efficiency of the heating systems. ORNL is managed by UT-Battelle, LLC, for the U.S. DOE under contract DE-AC-05-00OR22725.

  16. Thermodynamic analysis of heat recovery steam generator in combined cycle power plant

    Directory of Open Access Journals (Sweden)

    Ravi Kumar Naradasu

    2007-01-01

    Full Text Available Combined cycle power plants play an important role in the present energy sector. The main challenge in designing a combined cycle power plant is proper utilization of gas turbine exhaust heat in the steam cycle in order to achieve optimum steam turbine output. Most of the combined cycle developers focused on the gas turbine output and neglected the role of the heat recovery steam generator which strongly affects the overall performance of the combined cycle power plant. The present paper is aimed at optimal utilization of the flue gas recovery heat with different heat recovery steam generator configurations of single pressure and dual pressure. The combined cycle efficiency with different heat recovery steam generator configurations have been analyzed parametrically by using first law and second law of thermodynamics. It is observed that in the dual cycle high pressure steam turbine pressure must be high and low pressure steam turbine pressure must be low for better heat recovery from heat recovery steam generator.

  17. Exergy, Economic and Environmental Analysis for Simple and Combined Heat and Power IC Engines

    Directory of Open Access Journals (Sweden)

    Mehdi Aliehyaei

    2015-04-01

    Full Text Available This study reports the results of exergy, economic and environmental analyses of simple and combined heat and power internal combustion engines. Values of entropy production, second law efficiency are calculated, and an objective function, including initial, operation, maintenance and fuel costs, as well as the external costs of environmental pollutants, such as CO2, CO and NOx, are presented for the flue gas of the internal combustion engine. The results show that entropy generation in the combined heat and power mode is 30% lower than that in the simple internal combustion engine. Also, by excessively increasing the air ratio, the system entropy generation decreases in both cases of simple and combined heat and power IC engines. The greatest portion of entropy generation is related to the combined heat and power internal combustion engine. The gas heat exchanger generates more entropy than the jacket heat exchanger. Lower values of electricity cost and external costs of air pollution are provided by higher values of molar air to fuel ratio. The environmental aspects depend on location of the system and time of engine operation.

  18. Design of stationary PEFC system configurations to meet heat and power demands

    Science.gov (United States)

    Wallmark, Cecilia; Alvfors, Per

    This paper presents heat and power efficiencies of a modeled PEFC system and the methods used to create the system configuration. The paper also includes an example of a simulated fuel cell system supplying a building in Sweden with heat and power. The main method used to create an applicable fuel cell system configuration is pinch technology. This technology is used to evaluate and design a heat exchanger network for a PEFC system working under stationary conditions, in order to find a solution with high heat utilization. The heat exchanger network in the system connecting the reformer, the burner, gas cleaning, hot-water storage and the PEFC stack will affect the heat transferred to the hot-water storage and thereby the heating of the building. The fuel, natural gas, is reformed to a hydrogen-rich gas within a slightly pressurized system. The fuel processor investigated is steam reforming, followed by high- and low-temperature shift reactors and preferential oxidation. The system is connected to the electrical grid for backup and peak demands and to a hot-water storage to meet the varying heat demand for the building. The procedure for designing the fuel cell system installation as co-generation system is described, and the system is simulated for a specific building in Sweden during 1 year. The results show that the fuel cell system in combination with a burner and hot-water storage could supply the building with the required heat without exceeding any of the given limitations. The designed co-generation system will provide the building with most of its power requirements and would further generate income by sale of electricity to the power grid.

  19. District heating and cooling system for communities through power plant retrofit and distribution network. Final report, Phase I

    Energy Technology Data Exchange (ETDEWEB)

    1979-06-01

    The technical and economic feasibility of retrofitting thermal power plants in Minnesota to accommodate both heat and power generation for district heating was examined and is discussed. Three communities were identified as viable sites for co-generation district heating. (LCL)

  20. Component design considerations for gas turbine HTGR waste-heat power plant

    International Nuclear Information System (INIS)

    McDonald, C.F.; Vrable, D.L.

    1976-01-01

    Component design considerations are described for the ammonia waste-heat power conversion system of a large helium gas-turbine nuclear power plant under development by General Atomic Company. Initial component design work was done for a reference plant with a 3000-MW(t) High-Temperature Gas-Cooled Reactor (HTGR), and this is discussed. Advanced designs now being evaluated include higher core outlet temperature, higher peak system pressures, improved loop configurations, and twin 4000-MW(t) reactor units. Presented are the design considerations of the major components (turbine, condenser, heat input exchanger, and pump) for a supercritical ammonia Rankine waste heat power plant. The combined cycle (nuclear gas turbine and waste-heated plant) has a projected net plant efficiency of over 50 percent. While specifically directed towards a nuclear closed-cycle helium gas-turbine power plant (GT-HTGR), it is postulated that the bottoming waste-heat cycle component design considerations presented could apply to other low-grade-temperature power conversion systems such as geothermal plants

  1. Combined heat and power economic dispatch by a fish school search algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Leonardo Trigueiro dos; Costa e Silva, Marsil de Athayde [Undergraduate in Mechatronics Engineering, Pontifical Catholic University of Parana, Curitiba, PR (Brazil); Coelho, Leandro dos Santos [Industrial and Systems Engineering Graduate Program, PPGEPS, Pontifical Catholic University of Parana, Curitiba, PR (Brazil)], e-mail: leandro.coelho@pucpr.br

    2010-07-01

    The conversion of primary fossil fuels, such as coal and gas, to electricity is a a relatively inefficient process. Even the most modern combined cycle plants can only achieve efficiencies of between 50-60%. A great portion of the energy wasted in this conversion process is released to the environment as waste heat. The principle of combined heat and power, also known as cogeneration, is to recover and make beneficial use of this heat, significantly raising the overall efficiency of the conversion process. However, the optimal utilization of multiple combined heat and power systems is a complicated problem which needs powerful methods to solve. This paper presents a fish school search (FSS) algorithm to solve the combined heat and power economic dispatch problem. FSS is a novel approach recently proposed to perform search in complex optimization problems. Some simulations presented in the literature indicated that FSS can outperform many bio-inspired algorithms, mainly in multimodal functions. The search process in FSS is carried out by a population of limited-memory individuals - the fishes. Each fish represents a possible solution to the problem. Similarly to particle swarm optimization or genetic algorithm, search guidance in FSS is driven by the success of some individual members of the population. A four-unit system proposed recently which is a benchmark case in the power systems field has been validated as a case study in this paper. (author)

  2. Economic evaluation of heat extraction from nuclear power plants - a criterion for deciding their building order

    International Nuclear Information System (INIS)

    Navratil, J.

    1987-01-01

    Heat extraction from nuclear power plants is an important element in the current concept of supplying the population and industries with heat. Economic evaluation of the extraction is one of the factors of the total economic assessment of potential sites for nuclear power plant construction which can contribute to decision making on the priorities of construction. The methodological approach to the assessment of economic contribution of heat extraction from 2x1000 MW nuclear power plant is exemplified using three such sites on the Czechoslovak territory, viz., Opatovice (eastern Bohemia), Blahutovice (northern Moravia), and Kecerovce (eastern Slovakia). The so-called annual converted cost was used as a suitable quantity completely reflecting all significant economic effects of heat extraction. It is shown that the fuel component of the power plant costs is the decisive factor for the amount of the annual converted cost in respect to heat supply and thus also the economic priority of the construction sites of nuclear power plants. (Z.M.). 3 tabs., 3 refs

  3. Design and Construction of Power System for Induction Heating (IH) Cooker Using Resonant Converter

    International Nuclear Information System (INIS)

    Soe Thiri Thandar; Clement Saldanah; Win Khaing Moe

    2008-06-01

    Induction Heating (IH) systems using electromagnetic induction are developed in many industrial applications in Myanmar. Many industries have benefited from this new breakthrough by implementing induction heating for melting, hardening, and heating. Induction heating cooker is based on high frequency induction heating,electrical and electronic technologies. From the electronic point of view, induction heating cooker is composed of four parts.They are rectifier, filter, high frequency inverter, and resonant load. The purpose of this research is mainly objected to developed an induction heating cooker. The rectifier module is considered as full-bridge rectifier. The second protion of the system is a capacitive filter. The ripple components are minimized by this filter. The third is a high frequency converter to convert the constant DC to high frequency AC by switching the devices alternately. In this research, the Insulated Gate Bipolar Transistor (IGBT) will be used as a power source, and can be driven by the pulse signals from the pulse transformer circuit. In the resonant load, the power consumption is about 500W. Construction and testing has been carried out. The merits of this research work is that IH cooker can be developed because of having less energy consumption, safe, efficient, quick heating, and having efficiency of 90% or more

  4. City/industry/utility partnership leads to innovative combined heat and power project

    Energy Technology Data Exchange (ETDEWEB)

    Savage, J. [Savage and Associates, Quesnel, BC (Canada)

    2010-07-01

    This presentation discussed a combined heat and power (CHP) project that was launched in Quesnel, British Columbia. The CHP is being developed in phases in which new components will enter the system, providing added benefits. Hot oil from a sawmill bioenergy system will be used to heat lumber kilns, generate electricity at an Organic Rankine Cycle co-generation plant, and heat water for a District Energy Loop (DEL) to heat up to 22 existing buildings in the city as well as sawmill and planer buildings. The DEL piping would comprise a 5 kilometre loop. The energy would come from recovered sawmill space heating, recovered stack energy, and additional biomass energy. All of the district heating and 41 per cent of the power would be from heat recovered from the existing industrial operation. This bio-economy vision ultimately involves incorporating a biogas digester into the system to process food, regional organic waste, and pulp mill residuals, relying on bio-solids and heat from the mill. The fertilizer from the digester would then be used in a biomass plantation, which would provide materials to industry for many products, including bio-refining. This project evolved in response to concerns about the ecological effects and long-term economics of aggressive utilization of forest biomass. 15 figs.

  5. Power-to-heat in adiabatic compressed air energy storage power plants for cost reduction and increased flexibility

    Science.gov (United States)

    Dreißigacker, Volker

    2018-04-01

    The development of new technologies for large-scale electricity storage is a key element in future flexible electricity transmission systems. Electricity storage in adiabatic compressed air energy storage (A-CAES) power plants offers the prospect of making a substantial contribution to reach this goal. This concept allows efficient, local zero-emission electricity storage on the basis of compressed air in underground caverns. The compression and expansion of air in turbomachinery help to balance power generation peaks that are not demand-driven on the one hand and consumption-induced load peaks on the other. For further improvements in cost efficiencies and flexibility, system modifications are necessary. Therefore, a novel concept regarding the integration of an electrical heating component is investigated. This modification allows increased power plant flexibilities and decreasing component sizes due to the generated high temperature heat with simultaneously decreasing total round trip efficiencies. For an exemplarily A-CAES case simulation studies regarding the electrical heating power and thermal energy storage sizes were conducted to identify the potentials in cost reduction of the central power plant components and the loss in round trip efficiency.

  6. An analytical method for defining the pump`s power optimum of a water-to-water heat pump heating system using COP

    Directory of Open Access Journals (Sweden)

    Nyers Jozsef

    2017-01-01

    Full Text Available This paper analyzes the energy efficiency of the heat pump and the complete heat pump heating system. Essentially, the maximum of the coefficient of performance of the heat pump and the heat pump heating system are investigated and determined by applying a new analytical optimization procedure. The analyzed physical system consists of the water-to-water heat pump, circulation and well pump. In the analytical optimization procedure the "first derivative equal to zero" mathematical method is applied. The objective function is the coefficient of performance of the heat pump, and the heat pump heating system. By using the analytical optimization procedure and the objective function, as the result, the local and the total energy optimum conditions with respect to the mass flow rate of hot and cold water i. e. the power of circulation or well pump are defined.

  7. Optimal Power Consumption in a Central Heating System with Geothermal Heat Pump

    DEFF Research Database (Denmark)

    Tahersima, Fatemeh; Stoustrup, Jakob; Rasmussen, Henrik

    2011-01-01

    , lowering the temperature of forward water alleviates energy consumption. The hypothesis is that the minimum water temperature is achieved when at least one of the hydronic heaters in the building works at full capacity. The setpoint of the forward water temperature is found by solving a model based...... controllers. Simulation results for a case study with simplified subsystems' models show considerable energy savings compared to the traditional control scheme for the heat pump....

  8. Special considerations on operating a fuel cell power plant using natural gas with marginal heating value

    Energy Technology Data Exchange (ETDEWEB)

    Moses, L. Ng; Chien-Liang Lin [Industrial Technology Research Institute, Taiwan (China); Ya-Tang Cheng [Power Research Institute, Taiwan (China)

    1996-12-31

    In realizing new power generation technologies in Taiwan, a phosphoric acid fuel cell power plant (model PC2513, ONSI Corporation) has been installed in the premises of the Power Research Institute of the Taiwan Power Company in Taipei County of Taiwan. The pipeline gas supplying to the site of this power plant has a high percentage of carbon dioxide and thus a slightly lower heating value than that specified by the manufacturer. Because of the lowering of heating value of input gas, the highest Output power from the power plant is understandably less than the rated power of 200 kW designed. Further, the transient response of the power plant as interrupted from the Grid is also affected. Since this gas is also the pipeline gas supplying to the heavily populated Taipei Municipal area, it is conceivable that the success of the operations of fuel cells using this fuel is of vital importance to the promotion of the use of this power generation technology in Taiwan. Hence, experiments were set up to assess the feasibility of this fuel cell power plant using the existing pipeline gas in this part of Taiwan where fuel cells would most likely find useful.

  9. Radial heat conduction in a power reactor fuel element

    International Nuclear Information System (INIS)

    Ventura, M.A.

    1998-01-01

    Two radial conduction models, one for steady state and another for unsteady state, in a nuclear power reactor fuel element are developed. The objective is to obtain the temperatures in the fuel pellet and the cladding. The lumped-parameter hypothesis are adopted to represent the system. Both models are verified and their results are compared with similar ones. A method to calculate the conductance in the gap between the UO 2 pellet and the clad and its associated uncertainty is included in the steady state model. (author) [es

  10. Effects of the distribution density of a biomass combined heat and power plant network on heat utilisation efficiency in village-town systems.

    Science.gov (United States)

    Zhang, Yifei; Kang, Jian

    2017-11-01

    The building of biomass combined heat and power (CHP) plants is an effective means of developing biomass energy because they can satisfy demands for winter heating and electricity consumption. The purpose of this study was to analyse the effect of the distribution density of a biomass CHP plant network on heat utilisation efficiency in a village-town system. The distribution density is determined based on the heat transmission threshold, and the heat utilisation efficiency is determined based on the heat demand distribution, heat output efficiency, and heat transmission loss. The objective of this study was to ascertain the optimal value for the heat transmission threshold using a multi-scheme comparison based on an analysis of these factors. To this end, a model of a biomass CHP plant network was built using geographic information system tools to simulate and generate three planning schemes with different heat transmission thresholds (6, 8, and 10 km) according to the heat demand distribution. The heat utilisation efficiencies of these planning schemes were then compared by calculating the gross power, heat output efficiency, and heat transmission loss of the biomass CHP plant for each scenario. This multi-scheme comparison yielded the following results: when the heat transmission threshold was low, the distribution density of the biomass CHP plant network was high and the biomass CHP plants tended to be relatively small. In contrast, when the heat transmission threshold was high, the distribution density of the network was low and the biomass CHP plants tended to be relatively large. When the heat transmission threshold was 8 km, the distribution density of the biomass CHP plant network was optimised for efficient heat utilisation. To promote the development of renewable energy sources, a planning scheme for a biomass CHP plant network that maximises heat utilisation efficiency can be obtained using the optimal heat transmission threshold and the nonlinearity

  11. Heat transfer and structure stress analysis of micro packaging component of high power light emitting diode

    Directory of Open Access Journals (Sweden)

    Hsu Chih-Neng

    2013-01-01

    Full Text Available This paper focuses on the heat transfer and structural stress analysis of the micro- scale packaging structure of a high-power light emitting diode. The thermal-effect and thermal-stress of light emitting diode are determined numerically. Light emitting diode is attached to the silicon substrate through the wire bonding process by using epoxy as die bond material. The silicon substrate is etched with holes at the bottom and filled with high conductivity copper material. The chip temperature and structure stress increase with input power consumption. The micro light emitting diode is mounted on the heat sink to increase the heat dissipation performance, to decrease chip temperature, to enhance the material structure reliability and safety, and to avoid structure failure as well. This paper has successfully used the finite element method to the micro-scale light emitting diode heat transfer and stress concentration at the edges through etched holes.

  12. Soil warming for utilization and dissipation of waste heat from power generation in Pennsylvania

    International Nuclear Information System (INIS)

    DeWalle, D.R.

    1977-01-01

    The purpose of this paper is to describe the Penn State research project, which studies the soil warming by circulation of heated power plant discharge water through a buried pipe network. Waste heat can be utilized by soil warming for increased crop growth in open fields with proper selection of crops and cropping systems. Dissipation of waste heat from a buried pipe network can be predicted using either of two steady-state conduction equations tested. Accurate predictions are dependent upon estimates of the pipe outer-surface temperatures, soil surface temperatures in heated soil and soil thermal conductivity. The effect of economic optimization on soil-warming land area requirements for a 1500 MWe power plant in Pennsylvania is presented. (M.S.)

  13. High power heating in the ion cyclotron range of frequencies in the Wisconsin Tokapole II

    International Nuclear Information System (INIS)

    Biddle, A.P.; Sprott, J.C.

    1981-01-01

    Fast wave heating at the second, third and fourth harmonics of the ion cyclotron resonance, and slow wave heating at the fundamental in a single ion species hydrogen plasma, are found to be in good agreement with warm plasma theory at rf power levels <= 130 kW. Ion heating is negligible off an eigenmode. Ion body temperatures are more than doubled to 75 eV from the 35 eV ohmically heated case with tails comprising 8% of the plasma at 320 eV. No deleterious effects except a non-disruptive 10% shortening of the discharge length caused by impurity influx are noted. A passive mode tracking technique allows approximately equal to 40% increase in power deposition in a passing eigenmode over that of a fixed frequency rf source. Ion temperatures are limited by charge exchange due to the < 50 eV central temperature and the small 13 cm radius current channel. (author)

  14. Low grade heat driven adsorption system for cooling and power generation using advanced adsorbent materials

    International Nuclear Information System (INIS)

    Al-Mousawi, Fadhel Noraldeen; Al-Dadah, Raya; Mahmoud, Saad

    2016-01-01

    Highlights: • Adsorption system based on water and advanced physical adsorbents has the potential of producing cooling and power. • Adding an expander to physisorption system enhances efficiency by up to 11%. • MIL101Cr MOF can produce 95 W/kg and 1357 W/kg of specific power and cooling. • AQSOA Z02 can produce 73 W/kg and 640 W/kg of specific power and cooling. - Abstract: Globally there is abundance of low grade heat sources (around 150 °C) from renewables like solar energy or from industrial waste heat. The exploitation of such low grade heat sources will reduce fossil fuel consumption and CO_2 emissions. Adsorption technology offers the potential of using such low grade heat to generate cooling and power. In this work, the effect of using advanced adsorbent materials like AQSOA-Z02 (SAPO-34) zeolite and MIL101Cr Metal Organic Framework (MOF) at various operating conditions on power and cooling performance compared to that of commonly used silica-gel was investigated using water as refrigerant. A mathematical model for a two bed adsorption cooling cycle has been developed with the cycle modified to produce power by incorporating an expander between the desorber and the condenser. Results show that it is possible to produce power and cooling at the same time without affecting the cooling output. Results also show that for all adsorbents used as the heat source temperature increases, the cooling effect and power generated increase. As for increasing the cold bed temperature, this will decrease the cooling effect and power output except for SAPO-34 which shows slightly increasing trend of cooling and power output. As the condenser cooling temperature increases, the cooling effect and power output will decrease while for the chilled water temperature, the cooling load and power generated increased as the temperature increased. The maximum values of average specific power generation (SP), specific cooling power (SCP) and cycle efficiency are 73 W

  15. Dynamic modeling and evaluation of solid oxide fuel cell - combined heat and power system operating strategies

    Science.gov (United States)

    Nanaeda, Kimihiro; Mueller, Fabian; Brouwer, Jacob; Samuelsen, Scott

    Operating strategies of solid oxide fuel cell (SOFC) combined heat and power (CHP) systems are developed and evaluated from a utility, and end-user perspective using a fully integrated SOFC-CHP system dynamic model that resolves the physical states, thermal integration and overall efficiency of the system. The model can be modified for any SOFC-CHP system, but the present analysis is applied to a hotel in southern California based on measured electric and heating loads. Analysis indicates that combined heat and power systems can be operated to benefit both the end-users and the utility, providing more efficient electric generation as well as grid ancillary services, namely dispatchable urban power. Design and operating strategies considered in the paper include optimal sizing of the fuel cell, thermal energy storage to dispatch heat, and operating the fuel cell to provide flexible grid power. Analysis results indicate that with a 13.1% average increase in price-of-electricity (POE), the system can provide the grid with a 50% operating range of dispatchable urban power at an overall thermal efficiency of 80%. This grid-support operating mode increases the operational flexibility of the SOFC-CHP system, which may make the technology an important utility asset for accommodating the increased penetration of intermittent renewable power.

  16. High power RF heating and nonthermal distributions in tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Peeters, A.G.

    1994-12-13

    This thesis discusses the nonthermal effects in the electron population of a tokamak, that are generated by the inductive electric field and electron cyclotron resonant heating. The kinetic description of the plasma is given by a Boltzmann equation for the electron velocity distribution, in which the many small angle scattering Coulomb collisions that occur in the plasma are modelled by a Fokker-Planck collision term. These collisions drive the distribution towards the Maxwellian distribution of thermodynamic equilibrium. The energy absorption from the electron cyclotron waves and the acceleration by the toroidal electric field lead to deviations from the Maxwellian destribution. The interaction of the electron cyclotron waves with the plasma is treated within quasilinear theory. Resonant interaction occurs when the wave frequency matches one of the harmonics of the gyration frequency of the electrons in the static magnetic field. The waves generate a diffusion of resonant electrons in velocity space. The inductive electric field accelerates the electrons in the direction prallel to the magnetic field and leads to a convection in velocity space. The equilibrium that is reached between the driving forces of the electric field and the electron cyclotron waves and the restoring force of the collisions is studied in this thesis. The specific geometry of the tokamak is incorporated in the model through an average of the kinetic equation over the electron orbits. (orig./WL).

  17. High power RF heating and nonthermal distributions in tokamak plasmas

    International Nuclear Information System (INIS)

    Peeters, A.G.

    1994-01-01

    This thesis discusses the nonthermal effects in the electron population of a tokamak, that are generated by the inductive electric field and electron cyclotron resonant heating. The kinetic description of the plasma is given by a Boltzmann equation for the electron velocity distribution, in which the many small angle scattering Coulomb collisions that occur in the plasma are modelled by a Fokker-Planck collision term. These collisions drive the distribution towards the Maxwellian distribution of thermodynamic equilibrium. The energy absorption from the electron cyclotron waves and the acceleration by the toroidal electric field lead to deviations from the Maxwellian destribution. The interaction of the electron cyclotron waves with the plasma is treated within quasilinear theory. Resonant interaction occurs when the wave frequency matches one of the harmonics of the gyration frequency of the electrons in the static magnetic field. The waves generate a diffusion of resonant electrons in velocity space. The inductive electric field accelerates the electrons in the direction prallel to the magnetic field and leads to a convection in velocity space. The equilibrium that is reached between the driving forces of the electric field and the electron cyclotron waves and the restoring force of the collisions is studied in this thesis. The specific geometry of the tokamak is incorporated in the model through an average of the kinetic equation over the electron orbits. (orig./WL)

  18. On estimation of reliability for pipe lines of heat power plants under cyclic loading

    International Nuclear Information System (INIS)

    Verezemskij, V.G.

    1986-01-01

    One of the possible methods to obtain a quantitative estimate of the reliability for pipe lines of the welded heat power plants under cyclic loading due to heating-cooling and due to vibration is considered. Reliability estimate is carried out for a common case of loading by simultaneous cycles with different amplitudes and loading asymmetry. It is shown that scattering of the breaking number of cycles for the metal of welds may perceptibly decrease reliability of the welded pipe line

  19. High-Efficiency Small-Scale Combined Heat and Power Organic Binary Rankine Cycles

    OpenAIRE

    Costante Mario Invernizzi; Nadeem Ahmed Sheikh

    2018-01-01

    Small-CHP (Combined Heat and Power) systems are generally considered a valuable technological option to the conventional boilers, in a technology developed context. If small-CHP systems are associated with the use of renewable energies (biomass, for example) they could play an important role in distributed generation even in developing countries or, in any case, where there are no extensive electricity networks. Traditionally the considered heat engines for micro- or mini-CHP are: the gas eng...

  20. Hygiene problems in building a nuclear power and heat plant near Bratislava

    International Nuclear Information System (INIS)

    Chorvat, D.; Mizov, J.; Hladky, E.; Kubik, I.; Carach, J.

    1976-01-01

    The results are presented of the calculation of the population exposure due to the release of radioactive products from a nuclear power and heating plant accident into the ambient atmosphere (primary coolant circuit rupture) providing the nuclear power and heating plant is sited approximately 500 m from the Slovnaft chemical works in Bratislava. Ground water contamination was analyzed assuming the infiltration of radioactive products from a surface deposit due to fallout and the direct infiltration of the products into the soil in the area of the plant. The results of the assessment of the design basis accident of a WWER-1000 nuclear power and heating plant show unequivocally that the emergency core cooling system, full-pressure containment and the correct function of the containment spray system are able to keep the accident consequences within acceptable limits thus meeting radiation hygiene requirements related to the siting of similar installations in the vicinity of large housing estates. (Oy)

  1. Current status and development of heat exchangers for boiling water reactor nuclear power plant

    International Nuclear Information System (INIS)

    Uchiyama, Yoshio; Nishioka, Shuji; Ito, Shizuo

    1975-01-01

    More efficient and reliable operation is required for BWR heat exchangers because of nuclear plant safety and other reasons. Heat exchangers are classified into two categories of systems, the system for normal operation and the system for emergency operation. The present state and future improvement of heat exchangers are described in view of heat transfer performance, material selection, structural design, vibration, and so on. When noncondensing gas exists in vapour, heat transfer performance deteriorates, so that the heat transfer characteristics should be corrected by the adaption of venting the non condensing gas from the system. Heat transfer tubes should have high corrosion resistance to working fluid as well as high thermal conductivity, strength and economy. From that point of view, 30% cupro-nickel tubes will be replaced with 10% cupro-nickel tubes or titanium tubes though some technical development is necessary. These heat exchangers are now designed according to the MITI criteria for the technology concerning nuclear and thermal power generation, ASME Boiler and Pressure Vessel Code Sec. III and some other criteria. Most of heat transfer tube failures are caused from the tube vibration induced by working fluid flow, so that the vibration test and analysis were performed on U-tube elements. Some correction was obtained for design and fabrication techniques. (Iwase, T.)

  2. High-power microwave transmission and launching systems for fusion plasma heating systems

    International Nuclear Information System (INIS)

    Bigelow, T.S.

    1989-01-01

    Microwave power in the 30- to 300-GHz frequency range is becoming widely used for heating of plasma in present-day fusion energy magnetic confinement experiments. Microwave power is effective in ionizing plasma and heating electrons through the electron cyclotron heating (ECH) process. Since the power is absorbed in regions of the magnetic field where resonance occurs and launching antennas with narrow beam widths are possible, power deposition location can be highly controlled. This is important for maximizing the power utilization efficiency and improving plasma parameters. Development of the gyrotron oscillator tube has advanced in recent years so that a 1-MW continuous-wave, 140-GHz power source will soon be available. Gyrotron output power is typically in a circular waveguide propagating a circular electric mode (such as TE 0,2 ) or a whispering-gallery mode (such as TE 15,2 ), depending on frequency and power level. An alternative high-power microwave source currently under development is the free-electron laser (FEL), which may be capable of generating 2-10 MW of average power at frequencies of up to 500 GHz. The FEL has a rectangular output waveguide carrying the TE 0,1 mode. Because of its higher complexity and cost, the high-average-power FEL is not yet as extensively developed as the gyrotron. In this paper, several types of operating ECH transmission systems are discussed, as well systems currently being developed. The trend in this area is toward higher power and frequency due to the improvements in plasma density and temperature possible. Every system requires a variety of components, such as mode converters, waveguide bends, launchers, and directional couplers. Some of these components are discussed here, along with ongoing work to improve their performance. 8 refs

  3. Performance evaluation of a wavy-fin heat sink for power electronics

    International Nuclear Information System (INIS)

    Lorenzini, Marco; Fabbri, Giampietro; Salvigni, Sandro

    2007-01-01

    The almost daily increase in dissipated power per unit area of electronic components sets higher and higher demands on the performance of the heat sinks. These must not only be able to dissipate high heat fluxes, but must also keep costs to a minimum and exhibit a reliable behaviour. In this paper a novel, modular heat sink consisting of elements with wavy fin profile which can be pressed together to construct the component is presented. Its performance under steady-state conditions are assessed for the case of forced convection in terms of velocity distribution in the channels and global thermal resistance. Configurations with uniform and non-uniform heat flux are studied and some considerations are made as to the influence of the spacers between fan and heat sink proper

  4. Design of a sodium-air heat dissipator capable of transmitting powers till a megawatt

    International Nuclear Information System (INIS)

    Castellanos C, G.

    1977-01-01

    This is a theoretical study of the transport phenomenon in which emphasis is put on heat transference. From the chemical and nuclear point of view a revision is made of the sodium behavior as an agent of heat transference and as a fluid. The heat transference is analyzed on wide surfaces and the design of a sodium air heat dissipator capable of transferring powers at the range of a megawatt is presented with a simulation by computer. The results show that the heat transference coefficients don't vary in a great measure in relation with the temperature. This way we can use the caloric temperature for the determination of the sodium properties and the medium temperature for the determination of the air properties. (author)

  5. Bio-energy - For heat, electrical power or for fuel?

    International Nuclear Information System (INIS)

    Hawkins, A. C.

    2007-01-01

    This article examines the various uses proposed at a conference in Zurich, Switzerland on the use of biogenic fuels produced from sustainable biogenic resources. First of all, the term 'sustainable' in this connection is discussed and the energy obtained from wood, plants and crops is examined with respect to their total environmental impact. Energy crops are compared with other forms of renewable energy. The use of agricultural and foodstuff wastes as a source of biogenic material is discussed. Technical possibilities for their use are looked at. Wood-pellets as a fuel and the production of electricity in wood-fuelled power stations are discussed The energy and political dimensions of the use of so-called designer fuels are discussed along with their net negative effects on tropical forests and social structures in developing countries

  6. Micro power/heat cogeneration incorporating a stirling engine

    International Nuclear Information System (INIS)

    Luft, S.

    2003-01-01

    The Stirling-engine for CHP-purpose developed by SOLO is a trend-setting technology. It represents the most suspicious perspective apart from the fuel-cell technology in order to become suitable to the requirements of the future power supply in the focus of the sustainability and the decentralized energy supply. The charm of the Stirling technology is based on the external combustion: a so far not known variability with the primary energy choice as well as a life span substantially extending, wear-free operation are possible thereby. The external combustion reduces also the maintenance and the emissions in a measure not known with conventional engine technologies. The development steps are finished. The result is the world-wide first concept for the commercial, stationary application of decentralized micro-CHP on Stirling technology basis, which goes into series. (orig.) [de

  7. Waste Heat-to-Power Using Scroll Expander for Organic Rankine Bottoming Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Dieckmann, John [TIAX LLC, Lexington, MA (United States); Smutzer, Chad [TIAX LLC, Lexington, MA (United States); Sinha, Jayanti [TIAX LLC, Lexington, MA (United States)

    2017-05-30

    The objective of this program was to develop a novel, scalable scroll expander for conversion of waste heat to power; this was accomplished and demonstrated in both a bench-scale system as well as a full-scale system. The expander is a key component in Organic Rankine Cycle (ORC) waste heat recovery systems which are used to convert medium-grade waste heat to electric power in a wide range of industries. These types of waste heat recovery systems allow for the capture of energy that would otherwise just be exhausted to the atmosphere. A scroll expander has the benefit over other technologies of having high efficiency over a broad range of operating conditions. The speed range of the TIAX expander (1,200 to 3,600 RPM) enables the shaft power output to directly drive an electric generator and produce 60 Hz electric power without incurring the equipment costs or losses of electronic power conversion. This greatly simplifies integration with the plant electric infrastructure. The TIAX scroll expander will reduce the size, cost, and complexity of a small-scale waste heat recovery system, while increasing the system efficiency compared to the prevailing ORC technologies at similar scale. During this project, TIAX demonstrated the scroll expander in a bench-scale test setup to have isentropic efficiency of 70-75% and operated it successfully for ~200 hours with minimal wear. This same expander was then installed in a complete ORC system driven by a medium grade waste heat source to generate 5-7 kW of electrical power. Due to funding constraints, TIAX was unable to complete this phase of testing, although the initial results were promising and demonstrated the potential of the technology.

  8. A review of heat stress and its management in the power industry

    International Nuclear Information System (INIS)

    Waner, N.S.

    1986-01-01

    The effects of heat stress on plant operator performance is discussed. Sources of heat stress are reviewed, in particular, those unique to the Nuclear Power Industry. Measurement techniques correlating environmental conditions with physiological responses are covered, along with suggested assessment indices to establish criteria for worker health and safety. Available major countermeasures are described and include those categorized as, procedural, personal support systems, and plant betterment/engineering programs. Data, recommended standards, and industry practices are presented as viable guidelines along with references and information resources to assist the reader in establishing and implementing programs for managing heat stress

  9. High-power heating experiment of spherical tokamaks by use of plasma merging

    International Nuclear Information System (INIS)

    Ueda, Yoshinobu; Ono, Yasushi

    1999-01-01

    High-power heating of spherical tokamaks (STs) has been investigated experimentally by use of plasma merging effect. When two STs were coaxially collided, thermal energy of a colliding ST was injected into a target ST during short reconnection time (Alfven time). Though the thermal energy increment increased with decreasing plasma q value, thermal energy loss during the following relaxation, tended to be smaller with increasing q. The produced high-β STs had hallower current profiles and weaker paramagnetic toroidal field than those of single STs. Those heating properties indicate the plasma merging to be a promising initial heating method of ST plasmas. (author)

  10. Industrial space heating and cooling from stored spent nuclear power plant fuel

    International Nuclear Information System (INIS)

    Shaver, B.O.; Doman, J.W.

    1980-01-01

    Projections by the Department of Energy indicate that some 5800 metric tons of spent fuel from nuclear power reactors are now in storage and that some 33000 metric tons are expected to be in storage in 1990. The bulk of the spent fuel is currently stored in water-filled basins at the reactor sites from which the material was discharged. The thermal energy in the fuel is dissipated to atmospheres via a pumped water-to-air heat exchanger system. This paper describes a feasibility study of potential methods for the use of the heat. Also, potential applications of heat recovery systems at larger AFR storage facilities were investigated

  11. High-power ICRF and ICRF plus neutral-beam heating on PLT

    International Nuclear Information System (INIS)

    Hwang, D.; Bitter, M.; Budny, R.

    1983-01-01

    PLT ICRF experiments with RF powers up to approx.=3 MW have demonstrated efficient plasma heating in both the minority fundamental and the second harmonic ion-cyclotron regimes. In the minority 3 He regime, ion temperatures of approx.=3 keV have been produced along with approx.=1 kW of D- 3 He fusion power and substantial electron heating. In the second harmonic H regime, an equivalent averaged ion energy of approx.=4 keV has been achieved. Combined ICRF plus neutral-beam heating experiments with auxiliary powers totalling up to 4.5 MW have provided insight into auxiliary heating performance at stored plasma energy levels up to approx.=100 kJ. Values of #betta#sub(phi) in the range of 1.5-2% have been attained for Bsub(phi) approx.=17 kG. Energetic discharges with n-barsub(e) up to approx.6x10 13 cm - 3 at Bsub(phi) approx.=28 kG have also been investigated. Preliminary confinement studies suggest that energetic ion losses may contribute to a direct loss of the input RF power in the H minority heating regime but are insignificant in the 3 He minority case. The energy confinement time for the H minority regime is reduced somewhat from the Ohmic value. (author)

  12. A review on heat sink for thermo-electric power generation: Classifications and parameters affecting performance

    International Nuclear Information System (INIS)

    Elghool, Ali; Basrawi, Firdaus; Ibrahim, Thamir Khalil; Habib, Khairul; Ibrahim, Hassan; Idris, Daing Mohamad Nafiz Daing

    2017-01-01

    Highlights: • Coupling a thermoelectric power generation (TEG) to a heat sink is presented. • Review the classifications and parameters affecting performance of the TEG with heat sink. • Discuss different mathematical models of the heat sinks. • The passive heat sinks are most appropriate because of the inherent efficiency of TEG. • Medium temperature range below 300 °C is found to be most suitable for HPHS. - Abstract: In recent years, there have been growing interests in key areas related to global warming resulting from environmental emissions, and the diminishing sources of fossil fuel. The increased interest has led to significant research efforts towards finding novel technologies in clean energy production. Consequently, the merits of a thermo-electric generator (TEG) have promised a revival of alternative means of producing green energy. It is, however, impractical to account for the cost of thermal energy input to the TEG which is in the form of final waste heat. This is because the technology presents critical limitations in determining its cost efficiency nor its economic disadvantages. This paper reviews the principles of thermo-electric power production, as well the materials use, performance achieved, and application areas. The paper also takes a particular deliberation on TEG heat sinks geometries and categories. The review emphasizes more on the TEG performance while considering a number of heat sink parameters related to its performance.

  13. Heat treatment of large-sized welded rotors of steam turbines for atomic power stations

    Energy Technology Data Exchange (ETDEWEB)

    Kutasov, R F; Mukhina, M P; Tustanovskii, A S

    1977-01-01

    The heat treatment of a welded rotor of grade 25Kh2NMFA steel for steam turbines of nuclear power plants was considered. A following heat treatment schedule was suggested: charging the rotor in to a furnace at 100-150 deg C, heating to 200-250 deg C and holding for 12 hrs; slow heating (10 deg C/h) to 400-450 deg C and holding for 12 hrs; slow heating to 630-640 deg C and holding for 50 hrs, cooling at a rate of 5 deg C/h down to 100 deg C, holding for 20 hrs and cooling with the furnace open. The proposed heat treatment schedule of a duration of 356 hrs ensures a temperature gradient throughout the cross section and the length of the rotor of not more than +-5 deg C, least deviations of geometric dimensions and makes possible machining finish to within 0-0.02 mm. Described are the particularities of the design of a roll-out hearth electric chamber furnace, measuring 13000x5500x5000 mm and built for the purpose of carrying out said heat treatment. The power rating of the furnace is 2850 kW.

  14. Thermodynamic performance analysis and optimization of a solar-assisted combined cooling, heating and power system

    International Nuclear Information System (INIS)

    Wang, Jiangjiang; Lu, Yanchao; Yang, Ying; Mao, Tianzhi

    2016-01-01

    This study aims to present a thermodynamic performance analysis and to optimize the configurations of a hybrid combined cooling, heating and power (CCHP) system incorporating solar energy and natural gas. A basic natural gas CCHP system containing a power generation unit, a heat recovery system, an absorption cooling system and a storage tank is integrated with solar photovoltaic (PV) panels and/or a heat collector. Based on thermodynamic modeling, the thermodynamic performance, including energy and exergy efficiencies, under variable work conditions, such as electric load factor, solar irradiance and installation ratio, of the solar PV panels and heat collector is investigated and analyzed. The results of the energy supply side analysis indicate that the integration of solar PV into the CCHP system more efficiently improves the exergy efficiency, whereas the integration of a solar heat collector improves the energy efficiency. To match the building loads, the optimization method combined with the operation strategy is employed to optimize the system configurations to maximize the integrated benefits of energy and economic costs. The optimization results of demand–supply matching demonstrate that the integration of a solar heat collector achieves a better integrated performance than the solar PV integration in the specific case study. - Highlights: • Design a CCHP system integrated with solar PV and heat collector. • Present the energy and exergy analyses under variable work conditions. • Propose an optimization method of CCHP system for demand-supply matching.

  15. A study of a small nuclear power plant system for district heating

    International Nuclear Information System (INIS)

    Imamura, Mitsuru; Sato, Kotaro; Narabayashi, Tadashi; Shimazu, Yoichiro; Tsuji, Masashi

    2009-01-01

    We have studied nuclear power plant for district heating. Already some towns and villages in Hokkaido have requested small reactor for district heating. Using existing technology allows us to shorten development period and to keep a lid on development cost. We decided to develop new reactor based on 'MUTSU' reactor technology because 'MUTSU' had already proved its safety. And this reactor was boron free reactor. It allows plant system to reduce the chemical control system. And moderator temperature coefficient is deeply negative. It means to improve its operability and leads to dependability enhancement. We calculated burn-up calculation of erbium addition fuel. In the result, the core life became about 10 years. And we adapt the cassette type refueling during outagein in order to maintain nonproliferation. In the district heating system, a double heat exchanger system enables to response to load change in season. To obtain the acceptance of public, this system has a leak prevention system of radioactive materials to public. And road heating system of low grade heat utilization from turbine condenser leads to improve the heat utilization efficiency. We carried out performance evaluation test of district heating pipeline. Then the heat loss of pipeline is estimated at about 0.440degC/km. This result meets general condition, which is about 1degC/km. This small plant has passive safety system. It is natural cooling of containment vessel. In case of loss of coolant accident, decay heat can remove by natural convection air cooling after 6 hours. Decay heat within 6 hours can remove by evaporative heat transfer of pool on containment vessel. (author)

  16. Thermal analysis of heat and power plant with high temperature reactor and intermediate steam cycle

    Directory of Open Access Journals (Sweden)

    Fic Adam

    2015-03-01

    Full Text Available Thermal analysis of a heat and power plant with a high temperature gas cooled nuclear reactor is presented. The main aim of the considered system is to supply a technological process with the heat at suitably high temperature level. The considered unit is also used to produce electricity. The high temperature helium cooled nuclear reactor is the primary heat source in the system, which consists of: the reactor cooling cycle, the steam cycle and the gas heat pump cycle. Helium used as a carrier in the first cycle (classic Brayton cycle, which includes the reactor, delivers heat in a steam generator to produce superheated steam with required parameters of the intermediate cycle. The intermediate cycle is provided to transport energy from the reactor installation to the process installation requiring a high temperature heat. The distance between reactor and the process installation is assumed short and negligable, or alternatively equal to 1 km in the analysis. The system is also equipped with a high temperature argon heat pump to obtain the temperature level of a heat carrier required by a high temperature process. Thus, the steam of the intermediate cycle supplies a lower heat exchanger of the heat pump, a process heat exchanger at the medium temperature level and a classical steam turbine system (Rankine cycle. The main purpose of the research was to evaluate the effectiveness of the system considered and to assess whether such a three cycle cogeneration system is reasonable. Multivariant calculations have been carried out employing the developed mathematical model. The results have been presented in a form of the energy efficiency and exergy efficiency of the system as a function of the temperature drop in the high temperature process heat exchanger and the reactor pressure.

  17. Dual-pressure vaporization Kalina cycle for cascade reclaiming heat resource for power generation

    International Nuclear Information System (INIS)

    Guo, Zhanwei; Zhang, Zhi; Chen, Yaping; Wu, Jiafeng; Dong, Cong

    2015-01-01

    Graphical abstract: Schematic of the dual-pressure evaporation Kalina cycle. - Highlights: • Dual-pressure vaporization Kalina cycle for high-grade heat resource is investigated. • It is designed with 2nd evaporation branch for cascade utilization of heat resource. • Work and basic concentrations, dew point temperature of evaporation are optimized. • Power recovery efficiency of proposed cycle is 17% higher than that of Kalina cycle. • Dual-p vaporization Kalina cycle fits reclaiming heat resource higher than 350 °C. - Abstract: To further improve the cycle efficiency with the heat transfer curves between higher than 350 °C heat resource and the evaporating working medium of the Kalina cycle and to reduce the exhaust temperature of heat resource, the dual-pressure vaporization Kalina cycle for cascade utilization of high-to-mid grade heat resource is proposed. The optimization was conducted for parameters in this modified Kalina cycle such as concentrations of work solution and basic solution, evaporation dew point temperature. Under the conditions of inlet temperatures of heat resource and cooling water of respectively 400 °C and 25 °C and the constraints of proper heat transfer pinch point temperature differences, the maximum evaporation pressure not exceeds 20 MPa, the vapour quality at the turbine outlet is greater than 0.85 and the exhaust temperature of heat resource is not lower than 90 °C, the optimum parameters are obtained that the work and basic concentrations are 0.45 and 0.272 respectively, the dew point temperature of evaporation is 300 °C, and the corresponding power recovery efficiency of the dual-pressure vaporization Kalina cycle reaches 27%, which is 17% higher than that of the Kalina cycle with optimum parameters.

  18. Thermal power generation projects ``Large Scale Solar Heating``; EU-Thermie-Projekte ``Large Scale Solar Heating``

    Energy Technology Data Exchange (ETDEWEB)

    Kuebler, R.; Fisch, M.N. [Steinbeis-Transferzentrum Energie-, Gebaeude- und Solartechnik, Stuttgart (Germany)

    1998-12-31

    The aim of this project is the preparation of the ``Large-Scale Solar Heating`` programme for an Europe-wide development of subject technology. The following demonstration programme was judged well by the experts but was not immediately (1996) accepted for financial subsidies. In November 1997 the EU-commission provided 1,5 million ECU which allowed the realisation of an updated project proposal. By mid 1997 a small project was approved, that had been requested under the lead of Chalmes Industriteteknik (CIT) in Sweden and is mainly carried out for the transfer of technology. (orig.) [Deutsch] Ziel dieses Vorhabens ist die Vorbereitung eines Schwerpunktprogramms `Large Scale Solar Heating`, mit dem die Technologie europaweit weiterentwickelt werden sollte. Das daraus entwickelte Demonstrationsprogramm wurde von den Gutachtern positiv bewertet, konnte jedoch nicht auf Anhieb (1996) in die Foerderung aufgenommen werden. Im November 1997 wurden von der EU-Kommission dann kurzfristig noch 1,5 Mio ECU an Foerderung bewilligt, mit denen ein aktualisierter Projektvorschlag realisiert werden kann. Bereits Mitte 1997 wurde ein kleineres Vorhaben bewilligt, das unter Federfuehrung von Chalmers Industriteknik (CIT) in Schweden beantragt worden war und das vor allem dem Technologietransfer dient. (orig.)

  19. Some fabrication problems in nuclear power plants heat exchanges, its detectability and implications

    International Nuclear Information System (INIS)

    Condessa, N.C.; Oliveira, R.

    1988-01-01

    On the design and manufacturing follow-up of heat-exchangers of nuclear power plants some care are took into account in order to assure a high degree of confiability allowing the heat-exchanger in operation under severe and aggressive conditions be operating during the useful life of the nuclear power plant. However, despite the care, some problems can ocurr as the ones described on this job; that, if not detected in due time could bring umpleasant problems to the component or to the system in which it is working during operation. (author) [pt

  20. Regulatory Barriers for Flexible Coupling of the Nordic Power and District Heating Markets

    DEFF Research Database (Denmark)

    Skytte, Klaus; Olsen, Ole Jess

    2016-01-01

    that the choice of technologies for heat generation is mainly driven by outdated policies and tax conditions that create barriers for additional flexibility in the overall energy system. However, the balancing markets may be a main driver for introducing more electric boilers into DH and thereby increase its......Large share of variable renewable energy sources (VRE) is being deployed in the Nordic countries, especially wind power. This calls for additional flexibility of the power market. With the right coupling to the underlying national and local district heating (DH) markets, large shares of flexibility...

  1. The universal power and efficiency characteristics for irreversible reciprocating heat engine cycles

    CERN Document Server

    Qin Xiao Yong; Sun Feng Rui; Wu Chih

    2003-01-01

    The performance of irreversible reciprocating heat engine cycles with heat transfer loss and friction-like term loss is analysed using finite-time thermodynamics. The universal relations between the power output and the compression ratio, between the thermal efficiency and the compression ratio, and the optimal relation between power output and the efficiency of the cycles are derived. Moreover, analysis and optimization of the model were carried out in order to investigate the effect of cycle processes on the performance of the cycle using numerical examples. The results obtained herein include the performance characteristics of irreversible reciprocating Diesel, Otto, Atkinson and Brayton cycles.

  2. Numerical simulation of heat transfer in power law fluid flow through a stenosed artery

    Science.gov (United States)

    Talib, Amira Husni; Abdullah, Ilyani

    2017-11-01

    A numerical study of heat transfer in a power law fluid is investigated in this paper. The blood flow is treated as power law fluid with a presence of cosine shaped stenosis. This study reveals the effect of stenosis on the heat transfer and velocity of blood flowing in the constricted artery. The governing and energy equations are formulated in a cylindrical coordinate system. Hence, the set of equations and boundary conditions are solved numerically by Marker and Cell (MAC) method. The graphical result shows the profile of blood temperature is increased while the blood velocity is decreased at the critical height of stenosis.

  3. High-power ion-cyclotron-resonance heating in the Wisconsin Levitated Octupole

    International Nuclear Information System (INIS)

    Fortgang, C.M.

    1983-05-01

    Ion cyclotron resonance heating has been investigated, both experimentally and theoretically, on the Wisconsin Levitated Octupole. Heating of both ions and electrons has been observed. Typically, a two component ion energy distribution is produced (300 eV and 50 eV) with the application of 500 kW of rf power into a 5 x 10 12 cm -3 density plasma. Power is coupled to the plasma with an antenna that also serves as the inductor of an oscillator tank circuit. The oscillator is tunable from 1 to 3 MHz and can be applied for periods up to 10 msec. The experiments were performed with hydrogen, gun injected plasmas

  4. Thermodynamic effects when utilizing waste heat from condensation in cases of a reduced vacuum in steam turbine plants of thermal power stations, to provide heat at low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Vasiljevic, N.; Savic, B.; Stojakovic, M.

    1986-01-01

    There is an interesting variant of cogeneration in the steam turbine system of a thermal power plant, i.e. the utilisation of the waste heat of condensation with a reduced vacuum without reconstruction of the thermal power plant. The thermodynamic effect in cogeneration was calculated in consideration of the dynamics of heat consumption. This cogeneration process has the advantage of saving primary energy without reconstruction of the thermal power plant.

  5. Improved flexibility with large-scale variable renewable power in cities through optimal demand side management and power-to-heat conversion

    International Nuclear Information System (INIS)

    Salpakari, Jyri; Mikkola, Jani; Lund, Peter D.

    2016-01-01

    Highlights: • New models for optimal control of shiftable loads and power-to-heat conversion. • Full technical and economic potential with optimal controls. • Detailed time series of shiftable loads based on empirical data. • Case study of Helsinki (Finland) with over 90% share of district heating. • Positive net present values in cost-optimal operation. - Abstract: Solar and wind power are potential carbon-free energy solutions for urban areas, but they are also subject to large variability. At the same time, urban areas offer promising flexibility solutions for balancing variable renewable power. This paper presents models for optimal control of power-to-heat conversion to heating systems and shiftable loads in cities to incorporate large variable renewable power schemes. The power-to-heat systems comprise heat pumps, electric boilers, and thermal storage. The control strategies comprise optimal matching of load and production, and cost-optimal market participation with investment analysis. All analyses are based on hourly data. The models are applied to a case study in Helsinki, Finland. For a scheme providing ca. 50% of all electricity in the city through self-consumption of variable renewables, power-to-heat with thermal storage could absorb all the surplus production. A significant reduction in the net load magnitude was obtained with shiftable loads. Investments to both power-to-heat and load shifting with electric heating and commercial refrigeration have a positive net present value if the resources are controlled cost-optimally.

  6. Electrical power supply and process heat supply options

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    This paper consists of an economic analysis in which three geothermal electricity production scenarios are evaluated. The first is a 400 MW facility using cost and production data developed in this study. The other two are 400 and 880 MW units using cost data from a separate State of Hawaii study made to evaluate the economic feasibility of an interisland submersible electricity cable. In all cases, the scenarios are evaluated using the same economic model described, but in this case also reflecting depletion allowances permitted by the tax code. The output price is measured as cents per kWh, assuming delivery of the power to a bulk buyer at the plant fence. The two cases reflecting the State of Hawaii study use lower capital costs, which result in lower electricity prices when evaluated through the economic model. Since the assumptions of these two cases were not developed under this study, the resulting price figures are not used as part of the base case integrated systems. Rather, they are presented only as a special case, and are used as one scenario in the sensitivity analyses of integrated systems

  7. Combined heat and power in a liberalised energy market

    International Nuclear Information System (INIS)

    De Paepe, Michel; Mertens, David

    2007-01-01

    The decision whether or not to install cogeneration units mainly depends on individual economic considerations combined with ecological awareness. In countries with rather unfavourable economic conditions for cogeneration, government support or similar systems are considered to stimulate new investments. Although the economic feasibility of a cogeneration unit still strongly depends on site specific parameters, some general trends can be found. This paper clarifies which are the most important aspects in an economic evaluation of a cogeneration plant considering the context of a liberalised energy market. Also, a methodology for calculating the economic feasibility is set up. Firstly, the methodology is used to make a general analysis of the economic feasibility of cogeneration in Flanders, Belgium, taking into account the specific Flemish support systems. Different cogeneration technologies, including microturbines as a relatively new technology, are considered, as well as a broad range of sizes. Using average data makes it possible to compare those different sizes and technologies and to draw some general conclusions for the Flemish situation. After this case study, simulations are performed to quantify the impact of the variation of some crucial parameters on the economic feasibility of cogeneration. Ranking those parameters by their economic impact shows the high importance of the reliability of the installation and the power prices. The impact of changing energy prices is also examined, concluding that (gas fired) cogeneration should not fear the rise of gas prices. Where quantitative conclusions of this sensitivity analysis are based on specific inputs for Flanders, qualitative conclusions are still applicable to all similar countries

  8. The electrohydraulic balance of the solar heat storage with autonomous power supply

    Directory of Open Access Journals (Sweden)

    M. K. Marahtanov

    2014-01-01

    Full Text Available The introduction of the paper emphasizes an increasingly important role of alternative power sources nowadays. At the same time, a solar collector (suntrap is one of the most frequent techniques to use the solar energy. It is an absorber that picks up solar radiation and heats a heat carrier circulating in the close loop. Then the heat is transferred to the heat accumulator that is integrated in the hot-tap water system (HWS.The paper presents a prospective circuit of the solar collector. It differs from the traditional one because, in addition to absorbing panel, it uses photoconverters to generate electric power for the circulating pump. The advantage of this system is that for operation such a solar energy converter has no need in external power sources, i.e. it is autonomous. The need to calculate the essential thermo-physical parameters that ensure no-break system operation was stated as a main objective of the work.The suggested circuit has a photocell panel to convert solar radiation into dc voltage of 12 V. In case of a lack of the solar energy an accumulator battery can be used for feeding. To ensure the no-break supply of power an adaptor is offered.To calculate a density distribution of solar radiation a sine law is offered depending on the time of day and geographical locality. This dependence was used to obtain the expressions for calculating the water temperature in boiler over daytime.Further, the calculations have been done for the operating conditions under which an efficient heat exchange will be provided with the minimum consumption of electric power for the heat carrier circulation in the first loop. For this purpose, a pump power was calculated depending on consumption and hydraulic losses of head in the pipeline. As a minimum required consumption the value has been chosen at which a laminar flow regime changes to the turbulent one because of the most efficient heat exchange being both in collector and in heat accumulator

  9. 8 GHz, high power, microwave system for heating of thermonuclear plasmas

    International Nuclear Information System (INIS)

    Di Giovenale, S.; Fortunato, T.; Mirizzi, F.; Roccon, M.; Sassi, M.; Tuccillo, A.A.; Maffia, G.; Baldi, L.

    1993-01-01

    The Frascati Tokamak Upgrade (FTU) is a machine included in the European Thermonuclear Fusion Program aimed at investigating high density plasmas in the presence of powerful additional RF heating systems. The Lower Hybrid Resonant Heating (LHRH) system, based on 9 independent modules, works at 8 GHz, and will generate, at full performances, a total amount of 9 MW, in the pulsed regime (pulse length = 1 s, duty cycle = 1/600). The microwave power source is a gyrotron oscillator, developed by Thomson Tubes Electroniques (France) for this specific application, and capable of producing up to 1 MW. An overmoded, low loss, circular waveguide transmits the RF power toward the plasma; an array of 12x4 rectangular waveguides (the 'grill') launches this power into the plasma. The paper describes the LHRH system for FTU and analyses both its main performances and experimental results

  10. Problems of heat sources modeling on stage of isolated power systems expansion planning

    International Nuclear Information System (INIS)

    Malenkov, A.V.; Reshetnikova, L.N.; Sergeev, Yu.A.

    1998-01-01

    It is necessary to use computer codes for evaluation of possible applications and role of nuclear district heating plants in the local self-balancing power and heating systems, which are to be located in the remote isolated and hardly accessible regions in the Far North of Russia. Key factors in determining system configurations and its performances are: (1) interdependency of electricity, heat and fuel supply; (2) long distance between energy consumer centres (from several tens up to some hundred kilometers); and (3) difficulty in export and import of the electricity, especially the fuel in and from neighbouring and remote regions. The problem to challenge is to work out an optimum expansion plan of the local electricity and heat supply system. The ENPEP (ENergy and Power Evaluation Program) software package, which was developed by IAEA together with the USA Argonne National Laboratory, was chosen for this purpose. The Chaun-Bilibino power system (CBPS), an isolated power system in far North-East region of Russia, was selected as the first case of the ENPEP study. ENPEP allows a complex approach in the system expansion optimization planning in the time frame of planning period of up to 30 years. The key ENPEP module, ELECTRIC, considers electricity as the only product. The cogeneration part (heat production) must be considered outside the ELECTRIC model and then the results to be transfer ed to ELECTRIC. The ENPEP study on the Chaun-Bilibino isolated power system has shown that the modelling of the heat supply sources in ENPEP is not a trivial problem. It is very important and difficult to correctly represent specific features of cogeneration process at the same time. (author)

  11. Theoretical overview of heating power and necessary heating supply temperatures in typical Danish single-family houses from the 1900s

    DEFF Research Database (Denmark)

    Østergaard, Dorte Skaarup; Svendsen, Svend

    2016-01-01

    in typical Danish single-family houses constructed in the 1900s. The study provides a simplified theoretical overview of typical building constructions and standards for the calculation of design heat loss and design heating power in Denmark in the 1900s. The heating power and heating demand in six typical...... Danish single-family houses constructed in the 1900s were estimated based on simple steady-state calculations. We found that the radiators in existing single-family houses should not necessarilrbe expected to be over-dimensioned compared to current design heat loss. However, there is considerable...... potential for using low-temperature space heating in existing single-family houses in typical operation conditions. Older houses were not always found to require higher heating system temperatures than newer houses. We found that when these houses have gone through reasonable energy renovations, most...

  12. Stochastic PSO-based heat and power dispatch under environmental constraints incorporating CHP and wind power units

    Energy Technology Data Exchange (ETDEWEB)

    Piperagkas, G.S.; Anastasiadis, A.G.; Hatziargyriou, N.D. [National Technical University of Athens, School of Electrical and Computer Engineering, Electric Power Division, 9, Iroon Polytechneiou Str., GR-15773 Zografou, Athens (Greece)

    2011-01-15

    In this paper an extended stochastic multi-objective model for economic dispatch (ED) is proposed, that incorporates in the optimization process heat and power from CHP units and expected wind power. Stochastic restrictions for the CO{sub 2}, SO{sub 2} and NO{sub x} emissions are used as inequality constraints. The ED problem is solved using a multi-objective particle swarm optimization technique. The available wind power is estimated from a transformation of the wind speed considered as a random variable to wind power. Simulations are performed on the modified IEEE 30 bus network with 2 cogeneration units and actual wind data. Results concerning minimum cost and emissions reduction options are finally drawn. (author)

  13. A study of a small nuclear power plant system for district heating

    International Nuclear Information System (INIS)

    Imamura, Mitsuru; Sato, Kotaro; Narabayashi, Tadashi; Shimazu, Yoichiro; Tsuji, Masashi

    2008-01-01

    We have studied nuclear power plant for district heating. Already some towns and villages in Hokkaido have requested small reactor for district heating. Using existing technology allows us to shorten development period and to keep a lid on development cost. We decided to develop new reactor based on 'MUTSU' reactor technology. 'MUTSU' had already proved its safety. And 'MUTSU' reactor was boron free reactor. It allows plant system to become more compact and simple. And load following capability by core reactivity become bigger. It means to reduce control rod movement. It leads to dependability enhancement. We calculated burn-up calculation of erbium addition fuel. In the result the core life became about 10 years. In the district heating system, there are not only district heating but also snow melting with warm water. It uses steam condenser's heat, which are only discharged now. This small plant has passive safety system. It is natural cooling of containment vessel. In case of loss of coolant accident, decay heat can remove by natural convection air cooling after 6 hours. Decay heat within 6 hours can remove by evaporative heat transfer of pool on containment vessel. (author)

  14. Investigations of heat-hydraulic noises in the equipment for creation of power-saving technologies

    International Nuclear Information System (INIS)

    Proskuryakov, K.N.

    2000-01-01

    The results of experimental and theoretical studies on the parameters of vibroacoustic signals, originating in the TPP and NPP thermal energy equipment, are presented. The methods for calculation and identification of the heat-hydraulic perturbation sources, intended for improving the means of early diagnostics of anomalies in the technological process, forecasting their development, increasing the maintenance work efficiency and operational safety, as well as for creating power-saving technologies in the power engineering, are developed [ru

  15. Thermal Management of Transient Power Spikes in Electronics - Phase Change Energy Storage or Copper Heat Sinks?

    OpenAIRE

    Krishnan, S.; Garimella, S V

    2004-01-01

    A transient thermal analysis is performed to investigate thermal control of power semiconductors using phase change materials, and to compare the performance of this approach to that of copper heat sinks. Both the melting of the phase change material under a transient power spike input, as well as the resolidification process, are considered. Phase change materials of different kinds (paraffin waxes and metallic alloys) are considered, with and without the use of thermal conductivity enhancer...

  16. Productivity Enhancement of Solar Still with PV Powered Heating Coil and Chamber Step-Wise Basin

    Directory of Open Access Journals (Sweden)

    Salah Abdallah

    2018-03-01

    Full Text Available There is a strong need to improve the productivity of single slope solar still. PV generator powered electrical heater and chamber step-wise design were introduced to the conventional solar still. An experimental study was performed to investigate the effect of adding the above mentioned modifications on the output parameters of the modified solar still. The inclusion of PV-powered heating coil and chamber step-wise design enhanced the productivity of distiller by up to 1098%.

  17. Implementing CDIO project-based learning in training of Heat and Power engineers

    Science.gov (United States)

    Boiko, E. A.; Shishmarev, P. V.; Karabarin, D. I.; Yanov, S. R.; Pikalova, A. A.

    2017-11-01

    This paper presents the experience and current results of CDIO standards implementation in training of bachelors in Heat and Power Engineering at Thermal Power Stations academic department in Siberian Federal University. It provides information on methodology of modernization of educational programs, curricula and programs of disciplines in transition to CDIO project-based learning technology. Preliminary assessment and analysis of lessons learned and scaling perspectives are given.

  18. Experimental study of heating scheme effect on the inner divertor power footprint widths in EAST lower single null discharges

    Science.gov (United States)

    Deng, G. Z.; Xu, J. C.; Liu, X.; Liu, X. J.; Liu, J. B.; Zhang, H.; Liu, S. C.; Chen, L.; Yan, N.; Feng, W.; Liu, H.; Xia, T. Y.; Zhang, B.; Shao, L. M.; Ming, T. F.; Xu, G. S.; Guo, H. Y.; Xu, X. Q.; Gao, X.; Wang, L.

    2018-04-01

    A comprehensive work of the effects of plasma current and heating schemes on divertor power footprint widths is carried out in the experimental advanced superconducting tokamak (EAST). The divertor power footprint widths, i.e., the scrape-off layer heat flux decay length λ q and the heat spreading S, are crucial physical and engineering parameters for fusion reactors. Strong inverse scaling of λ q and S with plasma current have been demonstrated for both neutral beam (NB) and lower hybrid wave (LHW) heated L-mode and H-mode plasmas at the inner divertor target. For plasmas heated by the combination of the two kinds of auxiliary heating schemes (NB and LHW), the divertor power widths tend to be larger in plasmas with higher ratio of LHW power. Comparison between experimental heat flux profiles at outer mid-plane (OMP) and divertor target for NB heated and LHW heated L-mode plasmas reveals that the magnetic topology changes induced by LHW may be the main reason to the wider divertor power widths in LHW heated discharges. The effect of heating schemes on divertor peak heat flux has also been investigated, and it is found that LHW heated discharges tend to have a lower divertor peak heat flux compared with NB heated discharges under similar input power. All these findings seem to suggest that plasmas with LHW auxiliary heating scheme are better heat exhaust scenarios for fusion reactors and should be the priorities for the design of next-step fusion reactors like China Fusion Engineering Test Reactor.

  19. District Heating at Power Failures - Final Report; Fjaerrvaerme vid Elavbrott - Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Lauenburg, Patrick; Johansson, Per-Olof

    2008-11-15

    Our society is vulnerable to prolonged power cuts. In cold weather interrupted heating is one of the most serious threats. District heating is available at most locations in Sweden and if heat can be transferred to the connected buildings at a power failure, it is of great importance for securing energy supply. In this work it was found that there are good opportunities for upholding heat supply at a power failure through self-circulation in connected radiator system, which has previously been overlooked. Self Circulation occurs when there is a sufficiently large temperature difference between forward and return line in the radiator system. The control and circulation in radiator systems will fail, but if the district heating water can continue to pass through the heat exchangers of the radiator systems self-circulation can occur. A prerequisite for self-circulation in the individual buildings to work is therefore to district heating network can operate at a power failure. District heating supply must have back to maintain the production and distribution of district heating, which is not always the case. Our studies show that there is every reason to this. Moreover there are customers that have their own reserve aggregates, such as hospitals, which are dependent on the district heating network function. In an extensive power failure, it may be desirable to establish a smaller grid, separate from backbone, using local electricity generation. The establishment of such a network requires there is local production which can start to loose voltage networks and has necessary control equipment for the frequency approach. In Malmoe, it is now possible to establish a such a network with the help of local production units. A prerequisite is that there are consumption of heating. It is not unusual for power plants (which produce both electricity and heat) is dependent on the pipe system for cooling the production of electricity. One can from the results also argue that every

  20. Decay heat power of spent nuclear fuel of power reactors with high burnup at long-term storage

    Science.gov (United States)

    Ternovykh, Mikhail; Tikhomirov, Georgy; Saldikov, Ivan; Gerasimov, Alexander

    2017-09-01

    Decay heat power of actinides and fission products from spent nuclear fuel of power VVER-1000 type reactors at long-term storage is calculated. Two modes of storage are considered: mode in which single portion of actinides or fission products is loaded in storage facility, and mode in which actinides or fission products from spent fuel of one VVER reactor are added every year in storage facility during 30 years and then accumulated nuclides are stored without addition new nuclides. Two values of fuel burnup 40 and 70 MW·d/kg are considered for the mode of storage of single fuel unloading. For the mode of accumulation of spent fuel with subsequent storage, one value of burnup of 70 MW·d/kg is considered. Very long time of storage 105 years accepted in calculations allows to simulate final geological disposal of radioactive wastes. Heat power of fission products decreases quickly after 50-100 years of storage. The power of actinides decreases very slow. In passing from 40 to 70 MW·d/kg, power of actinides increases due to accumulation of higher fraction of 244Cm. These data are important in the back end of fuel cycle when improved cooling system of the storage facility will be required along with stronger radiation protection during storage, transportation and processing.

  1. Decay heat power of spent nuclear fuel of power reactors with high burnup at long-term storage

    Directory of Open Access Journals (Sweden)

    Ternovykh Mikhail

    2017-01-01

    Full Text Available Decay heat power of actinides and fission products from spent nuclear fuel of power VVER-1000 type reactors at long-term storage is calculated. Two modes of storage are considered: mode in which single portion of actinides or fission products is loaded in storage facility, and mode in which actinides or fission products from spent fuel of one VVER reactor are added every year in storage facility during 30 years and then accumulated nuclides are stored without addition new nuclides. Two values of fuel burnup 40 and 70 MW·d/kg are considered for the mode of storage of single fuel unloading. For the mode of accumulation of spent fuel with subsequent storage, one value of burnup of 70 MW·d/kg is considered. Very long time of storage 105 years accepted in calculations allows to simulate final geological disposal of radioactive wastes. Heat power of fission products decreases quickly after 50-100 years of storage. The power of actinides decreases very slow. In passing from 40 to 70 MW·d/kg, power of actinides increases due to accumulation of higher fraction of 244Cm. These data are important in the back end of fuel cycle when improved cooling system of the storage facility will be required along with stronger radiation protection during storage, transportation and processing.

  2. Guide to Combined Heat and Power Systems for Boiler Owners and Operators

    Energy Technology Data Exchange (ETDEWEB)

    Oland, CB

    2004-08-19

    Combined heat and power (CHP) or cogeneration is the sequential production of two forms of useful energy from a single fuel source. In most CHP applications, chemical energy in fuel is converted to both mechanical and thermal energy. The mechanical energy is generally used to generate electricity, while the thermal energy or heat is used to produce steam, hot water, or hot air. Depending on the application, CHP is referred to by various names including Building Cooling, Heating, and Power (BCHP); Cooling, Heating, and Power for Buildings (CHPB); Combined Cooling, Heating, and Power (CCHP); Integrated Energy Systems (IES), or Distributed Energy Resources (DER). The principal technical advantage of a CHP system is its ability to extract more useful energy from fuel compared to traditional energy systems such as conventional power plants that only generate electricity and industrial boiler systems that only produce steam or hot water for process applications. By using fuel energy for both power and heat production, CHP systems can be very energy efficient and have the potential to produce electricity below the price charged by the local power provider. Another important incentive for applying cogeneration technology is to reduce or eliminate dependency on the electrical grid. For some industrial processes, the consequences of losing power for even a short period of time are unacceptable. The primary objective of the guide is to present information needed to evaluate the viability of cogeneration for new or existing industrial, commercial, and institutional (ICI) boiler installations and to make informed CHP equipment selection decisions. Information presented is meant to help boiler owners and operators understand the potential benefits derived from implementing a CHP project and recognize opportunities for successful application of cogeneration technology. Topics covered in the guide follow: (1) an overview of cogeneration technology with discussions about benefits

  3. High-performance nanostructured thermoelectric generators for micro combined heat and power systems

    International Nuclear Information System (INIS)

    Zhang, Yanliang; Wang, Xiaowei; Cleary, Martin; Schoensee, Luke; Kempf, Nicholas; Richardson, Joseph

    2016-01-01

    Highlights: • A TEG is fabricated using high-efficiency nanostructured thermoelectric materials. • The TEG produces high power density of 2.1 W/cm"2 with 5.3% electrical efficiency. • A micro-CHP system is demonstrated by integrating the TEG into a gas-fired boiler. - Graphical Abstract: - Abstract: Micro combined heat and power (micro-CHP) systems are promising pathways to increase power generation efficiencies. Here a new class of micro-CHP system without moving parts is experimentally demonstrated by integrating high-temperature thermoelectric generators (TEGs) and residential gas-fired boilers, thus enabling wide applications. The TEGs fabricated using high-efficiency nanostructured bulk half-Heusler alloys generate ultrahigh power density of 2.1 W/cm"2 with 5.3% electrical efficiency under 500 °C temperature differences between the hot and cold sides. The TEG system harnesses the untapped exergy between the combustion gas and water, and converts thermal energy into electric power with 4% heat-to-electricity efficiency based on the total heat input into the TEGs. The high-performance TEGs open lots of opportunities to transform power generation technologies and improve energy efficiency.

  4. Critical heat flux phenomena in flow boiling during step wise and ramp wise power transients

    International Nuclear Information System (INIS)

    Celata, G.P.; Cumo, M.; D'Annibale, F.; Farello, G.E.; Abou Said, S.

    1987-01-01

    The present paper deals with the results of an experimental investigation of the forced flow critical heat flux during power transients in a vertically heated channel. Experiments were carried out with a Refrigerant-12 1oop employing a circular test section which was electrically and uniformly heated. The power transients were performed with the step-wise and ramp-wise increase of the power to the test section. The test parameters included several values of the initial power (before the transient) and the final power (at the end of the transient) in the case of step-wise transients and the slope of the ramp in the case of ramp-wise transients. The pressure and specific mass flow rate, which were kept constant during the power transient,were varied from 1.2 to 2.7 MPa and 850 to 1500 Kg/sm 2 , respectively. Correlations of the experimental data for the time-to-crisis in terms of the independent parameters of the system are also proposed and verified for different values of pressure,mass flow rate, and inlet subcooling

  5. Combined Heat and Power Systems for the Provision of Sustainable Energy from Biomass in Buildings

    Directory of Open Access Journals (Sweden)

    Ortwein Andreas

    2016-01-01

    Full Text Available Against the background of greenhouse gases causing climate change, combined heat and power (CHP systems fueled by biomass can efficiently supply energy with high flexibility. Such CHP systems will usually consist of one or more thermo-chemical conversion steps and at least one (the more or less separated electric power generation unit. Depending on the main products of the previous conversion steps (e.g. combustible gases or liquids, but also flue gases with sensible heat, different technologies are available for the final power conversion step. This includes steam cycles with steam turbines or engines and different working fluids (water, organic fluids, but also combustion based systems like gas turbines or gas engines. Further promising technologies include fuel cells with high electric efficiency. When integrating such CHP systems in buildings, there are different strategies, especially concerning electric power generation. While some concepts are focusing on base load production, others are regulated either by thermal or by electric power demand. The paper will give a systematic overview on the combination of thermo-chemical conversion of biomass and combined heat and power production technologies. The mentioned building integration strategies will be discussed, leading to conclusions for further research and development in that field.

  6. Thermal-hydraulic process for cooling, heating and power production with low-grade heat sources in residential sector

    International Nuclear Information System (INIS)

    Borgogno, R.; Mauran, S.; Stitou, D.; Marck, G.

    2017-01-01

    Highlights: • Assessment of solar thermal-hydraulic process for tri-generation application. • Choice of the most suitable working fluid pair (R1234yf/R1233zd). • Evaluation of the global annual performance in Mediterranean climate. • Global annual COP and heat amplification achieving 0.24 and 1.2 respectively. • Global annual performance achieving an electric efficiency of 3.7%. - Abstract: A new process based on thermal-hydraulic conversion actuated by low-grade thermal energy is investigated. Input thermal energy can be provided by the means of solar collectors, as well as other low temperature energy sources. In the following article, “thermo-hydraulic” term refers to a process involving an incompressible fluid used as an intermediate medium to transfer work hydraulically between different thermal operated components or sub-systems. The system aims at providing trigeneration energy features for the residential sector, that is providing heating, cooling and electrical power for meeting the energy needs of domestic houses. This innovative system is made of two dithermal processes (working at two different levels of temperatures) and featuring two different working fluids. The first process is able to directly supply either electrical energy generated by an hydraulic turbine or drives the second process thanks to the incompressible fluid, which is similar to a heat pump effect for heating or cooling purposes. The innovative aspect of this process relies on the use of an hydraulic transfer fluid to transfer the work between each sub-system and therefore simplifying the conversion chain. A model, assuming steady-state operation, is developed to assess the energy performances of different variants of this thermo-hydraulic process with various heat source temperatures (80–110 °C) or heat sinks (0–30 °C), as well as various pairs of working fluids. For instance, in the frame of a single-family home, located in the Mediterranean region, the working

  7. Optimal placement of combined heat and power scheme (cogeneration): application to an ethylbenzene plant

    International Nuclear Information System (INIS)

    Zainuddin Abd Manan; Lim Fang Yee

    2001-01-01

    Combined heat and power (CHP) scheme, also known as cogeneration is widely accepted as a highly efficient energy saving measure, particularly in medium to large scale chemical process plants. To date, CHP application is well established in the developed countries. The advantage of a CHP scheme for a chemical plant is two-fold: (i) drastically cut down on the electricity bill from on-site power generation (ii) to save the fuel bills through recovery of the quality waste heat from power generation for process heating. In order to be effective, a CHP scheme must be placed at the right temperature level in the context of the overall process. Failure to do so might render a CHP venture worthless. This paper discusses the procedure for an effective implementation of a CHP scheme. An ethylbenzene process is used as a case study. A key visualization tool known as the grand composite curves is used to provide an overall picture of the process heat source and heat sink profiles. The grand composite curve, which is generated based on the first principles of Pinch Analysis enables the CHP scheme to be optimally placed within the overall process scenario. (Author)

  8. Configuring a fuel cell based residential combined heat and power system

    Science.gov (United States)

    Ahmed, Shabbir; Papadias, Dionissios D.; Ahluwalia, Rajesh K.

    2013-11-01

    The design and performance of a fuel cell based residential combined heat and power (CHP) system operating on natural gas has been analyzed. The natural gas is first converted to a hydrogen-rich reformate in a steam reformer based fuel processor, and the hydrogen is then electrochemically oxidized in a low temperature polymer electrolyte fuel cell to generate electric power. The heat generated in the fuel cell and the available heat in the exhaust gas is recovered to meet residential needs for hot water and space heating. Two fuel processor configurations have been studied. One of the configurations was explored to quantify the effects of design and operating parameters, which include pressure, temperature, and steam-to-carbon ratio in the fuel processor, and fuel utilization in the fuel cell. The second configuration applied the lessons from the study of the first configuration to increase the CHP efficiency. Results from the two configurations allow a quantitative comparison of the design alternatives. The analyses showed that these systems can operate at electrical efficiencies of ∼46% and combined heat and power efficiencies of ∼90%.

  9. Mitigation of divertor heat loads by strike point sweeping in high power JET discharges

    Science.gov (United States)

    Silburn, S. A.; Matthews, G. F.; Challis, C. D.; Frigione, D.; Graves, J. P.; Mantsinen, M. J.; Belonohy, E.; Hobirk, J.; Iglesias, D.; Keeling, D. L.; King, D.; Kirov, K.; Lennholm, M.; Lomas, P. J.; Moradi, S.; Sips, A. C. C.; Tsalas, M.; Contributors, JET

    2017-12-01

    Deliberate periodic movement (sweeping) of the high heat flux divertor strike lines in tokamak plasmas can be used to manage the heat fluxes experienced by exhaust handling plasma facing components, by spreading the heat loads over a larger surface area. Sweeping has recently been adopted as a routine part of the main high performance plasma configurations used on JET, and has enabled pulses with 30 MW plasma heating power and 10 MW radiation to run for 5 s without overheating the divertor tiles. We present analysis of the effectiveness of sweeping for divertor temperature control on JET, using infrared camera data and comparison with a simple 2D heat diffusion model. Around 50% reduction in tile temperature rise is obtained with 5.4 cm sweeping compared to the un-swept case, and the temperature reduction is found to scale slower than linearly with sweeping amplitude in both experiments and modelling. Compatibility of sweeping with high fusion performance is demonstrated, and effects of sweeping on the edge-localised mode behaviour of the plasma are reported and discussed. The prospects of using sweeping in future JET experiments with up to 40 MW heating power are investigated using a model validated against existing experimental data.

  10. Mitigation of divertor heat loads by strike point sweeping in high power JET discharges

    International Nuclear Information System (INIS)

    Silburn, S A; Matthews, G F; Challis, C D; Belonohy, E; Iglesias, D; Keeling, D L; King, D; Kirov, K; Lomas, P J; Frigione, D; Graves, J P; Mantsinen, M J; Hobirk, J; Lennholm, M; Moradi, S; Sips, A C C; Tsalas, M

    2017-01-01

    Deliberate periodic movement (sweeping) of the high heat flux divertor strike lines in tokamak plasmas can be used to manage the heat fluxes experienced by exhaust handling plasma facing components, by spreading the heat loads over a larger surface area. Sweeping has recently been adopted as a routine part of the main high performance plasma configurations used on JET, and has enabled pulses with 30 MW plasma heating power and 10 MW radiation to run for 5 s without overheating the divertor tiles. We present analysis of the effectiveness of sweeping for divertor temperature control on JET, using infrared camera data and comparison with a simple 2D heat diffusion model. Around 50% reduction in tile temperature rise is obtained with 5.4 cm sweeping compared to the un-swept case, and the temperature reduction is found to scale slower than linearly with sweeping amplitude in both experiments and modelling. Compatibility of sweeping with high fusion performance is demonstrated, and effects of sweeping on the edge-localised mode behaviour of the plasma are reported and discussed. The prospects of using sweeping in future JET experiments with up to 40 MW heating power are investigated using a model validated against existing experimental data. (paper)

  11. Critical heat fluxes in tubular fuel elements of nuclear power reactors

    International Nuclear Information System (INIS)

    Subbotin, V.I.; Alekseev, G.V.; Peskov, O.L.

    1974-01-01

    The results of the experiments carried out show that with appropriate choice of tube, type and dimensions of intensifier the attainment of critical conditions at certain parameters is not accompanied by sharp or considerable increases in temperature of the heat removing surface. Increase in power to above critical under these conditions does not lead to considerable variation in temperature either. Thus, it appears possible to change from heat removal by steam-water mixture to convective heat removal by wet steam without manifestation of intolerable temperature conditions of the heating surface (Fig. 6). A change to convective heat removal by wet steam is possible at different levels of heat fluxes which depend during constant conditions at the inlet on tube length and the degree of the disturbing influence on the flow. This is especially important since in principle the possibility arises for developing a power reactor with tubular fuel elements, in which a once-through cycle with steam superheat involving no intermediate separation can be realised

  12. An underground nuclear power station using self-regulating heat-pipe controlled reactors

    Science.gov (United States)

    Hampel, V.E.

    1988-05-17

    A nuclear reactor for generating electricity is disposed underground at the bottom of a vertical hole that can be drilled using conventional drilling technology. The primary coolant of the reactor core is the working fluid in a plurality of thermodynamically coupled heat pipes emplaced in the hole between the heat source at the bottom of the hole and heat exchange means near the surface of the earth. Additionally, the primary coolant (consisting of the working fluid in the heat pipes in the reactor core) moderates neutrons and regulates their reactivity, thus keeping the power of the reactor substantially constant. At the end of its useful life, the reactor core may be abandoned in place. Isolation from the atmosphere in case of accident or for abandonment is provided by the operation of explosive closures and mechanical valves emplaced along the hole. This invention combines technology developed and tested for small, highly efficient, space-based nuclear electric power plants with the technology of fast- acting closure mechanisms developed and used for underground testing of nuclear weapons. This invention provides a nuclear power installation which is safe from the worst conceivable reactor accident, namely, the explosion of a nuclear weapon near the ground surface of a nuclear power reactor. 5 figs.

  13. Underground nuclear power station using self-regulating heat-pipe controlled reactors

    Science.gov (United States)

    Hampel, Viktor E.

    1989-01-01

    A nuclear reactor for generating electricity is disposed underground at the bottom of a vertical hole that can be drilled using conventional drilling technology. The primary coolant of the reactor core is the working fluid in a plurality of thermodynamically coupled heat pipes emplaced in the hole between the heat source at the bottom of the hole and heat exchange means near the surface of the earth. Additionally, the primary coolant (consisting of the working flud in the heat pipes in the reactor core) moderates neutrons and regulates their reactivity, thus keeping the power of the reactor substantially constant. At the end of its useful life, the reactor core may be abandoned in place. Isolation from the atmosphere in case of accident or for abandonment is provided by the operation of explosive closures and mechanical valves emplaced along the hole. This invention combines technology developed and tested for small, highly efficient, space-based nuclear electric power plants with the technology of fast-acting closure mechanisms developed and used for underground testing of nuclear weapons. This invention provides a nuclear power installation which is safe from the worst conceivable reactor accident, namely, the explosion of a nuclear weapon near the ground surface of a nuclear power reactor.

  14. A review of solar energy based heat and power generation systems

    DEFF Research Database (Denmark)

    Modi, Anish; Bühler, Fabian; Andreasen, Jesper Graa

    2017-01-01

    The utilization of solar energy based technologies has attracted increased interest in recent times in order to satisfy the various energy demands of our society. This paper presents a thorough review of the open literature on solar energy based heat and power plants. In order to limit the scope ...

  15. Diffusion of combined heat and power in Dutch greenhouses : A case study

    NARCIS (Netherlands)

    Dijkema, G.P.J.; Kasmire, J.; Van der Veen, R.A.C.

    2012-01-01

    This report presents the case study of the rapid diffusion of combined heat and power (CHP) units in the Dutch greenhouse horticulture in the period 2003-2009. The aim of the case study is to find explanations for this particular transition, and to generalize on the nature of technology diffusion

  16. Underground nuclear power station using self-regulating heat-pipe controlled reactors

    International Nuclear Information System (INIS)

    Hampel, V.E.

    1989-01-01

    The author presents a nuclear reactor for generating electricity disposed underground at the bottom of a vertical hole that can be drilled using conventional drilling technology. The primary coolant of the reactor core is the working fluid in a plurality of thermodynamically coupled heat pipes emplaced in the hole between the heat source at the bottom of the hole and heat exchange means near the surface of the earth. Additionally, the primary coolant (consisting of the working fluid in the heat pipes in the reactor core) moderates neutrons and regulates their reactivity, thus keeping the power of the reactor substantially constant. At the end of its useful life, the reactor core may be abandoned in place. Isolation from the atmosphere in case of accident or for abandonment is provided by the operation of explosive closures and mechanical valves emplaced along the hole. This invention combines technology developed and tested for small, highly efficient, space-based nuclear electric power plants with the technology of fast-acting closure mechanisms developed and used for underground testing of nuclear weapons. This invention provides a nuclear power installation which is safe from the worst conceivable reactor accident, namely, the explosion of a nuclear weapon near the ground surface of a nuclear power reactor

  17. A thermoelectric generator using loop heat pipe and design match for maximum-power generation

    KAUST Repository

    Huang, Bin-Juine; Hsu, Po-Chien; Tsai, Rung-Je; Hussain, Muhammad Mustafa

    2015-01-01

    of noise. The experiments for a TEG with 4W rated power show that the LHP performs very well with overall thermal resistance 0.35 K W-1, from the cold side of TEG module to the ambient. The LHP is able to dissipate heat up to 110W and is maintenance free

  18. Specific power reduction of an ion source due to heating and cathode sputtering of electrodes

    International Nuclear Information System (INIS)

    Hamilton, G.U.; Semashko, N.N.

    The potentialities and limitations of the water-cooled ion-optical system of the ion source designed for continuous operation of the high-power neutral beam injector are determined. The following problems are analyzed: thermal expansion and deformation of electrodes, electrode sputtering as a result of bombardment, and heat transfer to turbulent flow of water

  19. Carbon Emissions Trading and Combined Heat and Power Strategies: Unintended Consequences

    Science.gov (United States)

    Tysseling, John C.; Vosevich, Mary; Boersma, Benjamin R.; Zumwalt, Jefferey A.

    2009-01-01

    Facility professionals continuously search for projects that reduce energy consumption and operating costs so as to directly benefit their bottom line. Many institutions nationwide have contemplated or made investments in combined heat and power (CHP) projects as a life-cycle strategy to minimize operating costs. However, recent sustainability and…

  20. High-Power Laser Cutting of Steel Plates: Heat Affected Zone Analysis

    Directory of Open Access Journals (Sweden)

    Imed Miraoui

    2016-01-01

    Full Text Available The thermal effect of CO2 high-power laser cutting on cut surface of steel plates is investigated. The effect of the input laser cutting parameters on the melted zone depth (MZ, the heat affected zone depth (HAZ, and the microhardness beneath the cut surface is analyzed. A mathematical model is developed to relate the output process parameters to the input laser cutting parameters. Three input process parameters such as laser beam diameter, cutting speed, and laser power are investigated. Mathematical models for the melted zone and the heat affected zone depth are developed by using design of experiment approach (DOE. The results indicate that the input laser cutting parameters have major effect on melted zone, heat affected zone, and microhardness beneath cut surface. The MZ depth, the HAZ depth, and the microhardness beneath cut surface increase as laser power increases, but they decrease with increasing cutting speed. Laser beam diameter has a negligible effect on HAZ depth but it has a remarkable effect on MZ depth and HAZ microhardness. The melted zone depth and the heat affected zone depth can be reduced by increasing laser cutting speed and decreasing laser power and laser beam diameter.

  1. Exergy analysis and evolutionary optimization of boiler blowdown heat recovery in steam power plants

    International Nuclear Information System (INIS)

    Vandani, Amin Mohammadi Khoshkar; Bidi, Mokhtar; Ahmadi, Fatemeh

    2015-01-01

    Highlights: • Heat recovery of boiler blow downed water using a flash tank is modeled. • Exergy destruction of each component is calculated. • Exergy efficiency of the whole system is optimized using GA and PSO algorithms. • Utilizing the flash tank increases the net power and efficiency of the system. - Abstract: In this study, energy and exergy analyses of boiler blowdown heat recovery are performed. To evaluate the effect of heat recovery on the system performance, a steam power plant in Iran is selected and the results of implementation of heat recovery system on the power plant are investigated. Also two different optimization algorithms including GA and PSO are established to increase the plant efficiency. The decision variables are extraction pressure from steam turbine and temperature and pressure of boiler outlet stream. The results indicate that using blowdown recovery technique, the net generated power increases 0.72%. Also energy and exergy efficiency of the system increase by 0.23 and 0.22, respectively. The optimization results show that temperature and pressure of boiler outlet stream have a higher effect on the exergy efficiency of the system in respect to the other decision variables. Using optimization methods, exergy efficiency of the system reaches to 30.66% which shows a 1.86% augmentation with regard to the situation when a flash tank is implemented.

  2. Options for greenhouse emission reduction by using a module for combined heat and power generation

    International Nuclear Information System (INIS)

    Stankov, Nikola; Ivanov, Bozhidar

    2009-01-01

    This report contains example of CO 2 emission reduction assessment when using module for combined heat and power generation that is fueled by natural gas. Environmental benefits are related to the type of fuel that is used and the increased efficiency of the combined production process. Choosing of the CHP unit and the assessment scheme are also presented

  3. Power module packaging with double sided planar interconnection and heat exchangers

    Science.gov (United States)

    Liang, Zhenxian; Marlino, Laura D.; Ning, Puqi; Wang, Fei

    2015-05-26

    A double sided cooled power module package having a single phase leg topology includes two IGBT and two diode semiconductor dies. Each IGBT die is spaced apart from a diode semiconductor die, forming a switch unit. Two switch units are placed in a planar face-up and face-down configuration. A pair of DBC or other insulated metallic substrates is affixed to each side of the planar phase leg semiconductor dies to form a sandwich structure. Attachment layers are disposed on outer surfaces of the substrates and two heat exchangers are affixed to the substrates by rigid bond layers. The heat exchangers, made of copper or aluminum, have passages for carrying coolant. The power package is manufactured in a two-step assembly and heating process where direct bonds are formed for all bond layers by soldering, sintering, solid diffusion bonding or transient liquid diffusion bonding, with a specially designed jig and fixture.

  4. Numerical simulation of nanofluids based on power-law fluids with flow and heat transfer

    Science.gov (United States)

    Li, Lin; Jiang, Yongyue; Chen, Aixin

    2017-04-01

    In this paper, we investigate the heat transfer of nanofluids based on power-law fluids and movement of nanoparticles with the effect of thermophoresis in a rotating circular groove. The velocity of circular groove rotating is a constant and the temperature on the wall is kept to be zero all the time which is different from the temperature of nanofluids in the initial time. The effects of thermophoresis and Brownian diffusion are considered in temperature and concentration equations, and it is assumed that the thermal conductivity of nanofluids is a function of concentration of nanoparticles. Based on numerical results, it can be found that nanofluids improve the process of heat transfer than base fluids in a rotating circular groove. The enhancement of heat transfer increases as the power law index of base fluids decreases.

  5. The General-Purpose Heat Source Radioisotope Thermoelectric Generator: Power for the Galileo and Ulysses missions

    International Nuclear Information System (INIS)

    Bennett, G.L.; Lombardo, J.J.; Hemler, R.J.; Peterson, J.R.

    1986-01-01

    Electrical power for NASA's Galileo mission to Jupiter and ESA's Ulysses mission to explore the polar regions of the Sun will be provided by General-Purpose Heat Source Radioisotope Thermo-electric Generators (GPHS-RTGs). Building upon the successful RTG technology used in the Voyager program, each GPHS-RTG will provide at least 285 W(e) at beginning-of-mission. The design concept has been proven through extensive tests of an electrically heated Engineering Unit and a nuclear-heated Qualification Unit. Four flight generators have been successfully assembled and tested for use on the Galileo and Ulysses spacecraft. All indications are that the GPHS-RTGs will meet or exceed the power requirement of the missions

  6. Rehabilitation of heat exchange equipment a key to power plant life extension and performance improvement

    Energy Technology Data Exchange (ETDEWEB)

    Taveau, F.; Huiban, A.M. [Alstom Power Heat Exchange, 78 - Velizy Villacoublay (France)

    2001-07-01

    With the current evolutions of the energy market and the life extension of the power plants, all the equipment initially supplied need one day or another partial or total rehabilitation. For heat exchange equipment, this includes the condensers, feed water heaters and various heat exchangers. Modernization is in particular necessary when in-service monitoring and periodic inspections show significant deteriorations of the tubes and cooling water leakages leading to forced outages or when tube and tube plate materials are no longer suited to cooling water characteristics or to updated specifications of the secondary system. Feedwater heaters and heat exchangers damaged by erosion/corrosion, vibrations, etc. can be re-designed, manufactured and replaced easily. The operation is more complex on condensers and requires technical surveys, study of alternative solutions and has a more direct impact on the global output of the power plant. That is why our conference will focus on the condenser refurbishment. (author)

  7. Heat transfer in the core graphite structures of RBMK nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Knoglinger, E., E-mail: ernst.knoglinger@a1.net [Am Winklerwald 15, A 4020 Linz (Austria); Wölfl, H., E-mail: herbert.woelfl@tele2.at [Berg, Im Weideland 19, A 4060 Linz (Austria); Kaliatka, A., E-mail: algirdas.kaliatka@lei.lt [Laboratory of Nuclear Installation Safety, Lithuanian Energy Institute, Breslaujos 3, LT-44403 Kaunas (Lithuania)

    2015-11-15

    Highlights: • Proposed solution of heat transfer model from a hollow cylinder to a fluid through narrow duct. • Thermal conductance of annular gaps, filled by two component gas was discussed. • Xenon transient preceding the Chernobyl Accident was analyzed. • Reactivity balance during power manoeuvres and potenrial causes of the accident were discussed. - Abstract: Conductive and combined radiative/conductive gap conductance models are presented and discussed in great detail. The heat resistance concept and an exact solution to the one dimensional heat conduction equation for a 3-region composite hollow cylinder are used to calculate gap conductance in function of gap gas composition and fuel burn up. The study includes the back calculation of a reactor experiment performed at the Ignalina NPP Unit-1 which provides some insight in the function of the RBMK nitrogen supply and regulating device and an investigation of the role the graphite temperature played during the power manoeuvres preceding the Chernobyl Accident.

  8. Rehabilitation of heat exchange equipment a key to power plant life extension and performance improvement

    International Nuclear Information System (INIS)

    Taveau, F.; Huiban, A.M.

    2001-01-01

    With the current evolutions of the energy market and the life extension of the power plants, all the equipment initially supplied need one day or another partial or total rehabilitation. For heat exchange equipment, this includes the condensers, feed water heaters and various heat exchangers. Modernization is in particular necessary when in-service monitoring and periodic inspections show significant deteriorations of the tubes and cooling water leakages leading to forced outages or when tube and tube plate materials are no longer suited to cooling water characteristics or to updated specifications of the secondary system. Feedwater heaters and heat exchangers damaged by erosion/corrosion, vibrations, etc. can be re-designed, manufactured and replaced easily. The operation is more complex on condensers and requires technical surveys, study of alternative solutions and has a more direct impact on the global output of the power plant. That is why our conference will focus on the condenser refurbishment. (author)

  9. System Statement of Tasks of Calculating and Providing the Reliability of Heating Cogeneration Plants in Power Systems

    Science.gov (United States)

    Biryuk, V. V.; Tsapkova, A. B.; Larin, E. A.; Livshiz, M. Y.; Sheludko, L. P.

    2018-01-01

    A set of mathematical models for calculating the reliability indexes of structurally complex multifunctional combined installations in heat and power supply systems was developed. Reliability of energy supply is considered as required condition for the creation and operation of heat and power supply systems. The optimal value of the power supply system coefficient F is based on an economic assessment of the consumers’ loss caused by the under-supply of electric power and additional system expences for the creation and operation of an emergency capacity reserve. Rationing of RI of the industrial heat supply is based on the use of concept of technological margin of safety of technological processes. The definition of rationed RI values of heat supply of communal consumers is based on the air temperature level iside the heated premises. The complex allows solving a number of practical tasks for providing reliability of heat supply for consumers. A probabilistic model is developed for calculating the reliability indexes of combined multipurpose heat and power plants in heat-and-power supply systems. The complex of models and calculation programs can be used to solve a wide range of specific tasks of optimization of schemes and parameters of combined heat and power plants and systems, as well as determining the efficiency of various redundance methods to ensure specified reliability of power supply.

  10. Modeling and optimization of a heat-pump-assisted high temperature proton exchange membrane fuel cell micro-combined-heat-and-power system for residential applications

    DEFF Research Database (Denmark)

    Arsalis, Alexandros; Kær, Søren Knudsen; Nielsen, Mads Pagh

    2015-01-01

    In this study a micro-combined-heat-and-power (micro-CHP) system is coupled to a vapor-compression heat pump to fulfill the residential needs for heating (space heating and water heating) and electricity in detached single-family households in Denmark. Such a combination is assumed to be attractive...... for application, since both fuel cell technology and electric heat pumps are found to be two of the most efficient technologies for generation/conversion of useful energy. The micro-CHP system is fueled with natural gas and includes a fuel cell stack, a fuel processor and other auxiliary components. The micro......-CHP system assumes heat-led operation, to avoid dumping of heat and the use of complicated thermal energy storage. The overall system is grid-interconnected to allow importing and exporting of electricity as necessary. In this study emphasis is given on the operational characterization of the system...

  11. The relationship among CPU utilization, temperature, and thermal power for waste heat utilization

    International Nuclear Information System (INIS)

    Haywood, Anna M.; Sherbeck, Jon; Phelan, Patrick; Varsamopoulos, Georgios; Gupta, Sandeep K.S.

    2015-01-01

    Highlights: • This work graphs a triad relationship among CPU utilization, temperature and power. • Using a custom-built cold plate, we were able capture CPU-generated high quality heat. • The work undertakes a radical approach using mineral oil to directly cool CPUs. • We found that it is possible to use CPU waste energy to power an absorption chiller. - Abstract: This work addresses significant datacenter issues of growth in numbers of computer servers and subsequent electricity expenditure by proposing, analyzing and testing a unique idea of recycling the highest quality waste heat generated by datacenter servers. The aim was to provide a renewable and sustainable energy source for use in cooling the datacenter. The work incorporates novel approaches in waste heat usage, graphing CPU temperature, power and utilization simultaneously, and a mineral oil experimental design and implementation. The work presented investigates and illustrates the quantity and quality of heat that can be captured from a variably tasked liquid-cooled microprocessor on a datacenter server blade. It undertakes a radical approach using mineral oil. The trials examine the feasibility of using the thermal energy from a CPU to drive a cooling process. Results indicate that 123 servers encapsulated in mineral oil can power a 10-ton chiller with a design point of 50.2 kW th . Compared with water-cooling experiments, the mineral oil experiment mitigated the temperature drop between the heat source and discharge line by up to 81%. In addition, due to this reduction in temperature drop, the heat quality in the oil discharge line was up to 12.3 °C higher on average than for water-cooled experiments. Furthermore, mineral oil cooling holds the potential to eliminate the 50% cooling expenditure which initially motivated this project

  12. High-temperature and high-power-density nanostructured thermoelectric generator for automotive waste heat recovery

    International Nuclear Information System (INIS)

    Zhang, Yanliang; Cleary, Martin; Wang, Xiaowei; Kempf, Nicholas; Schoensee, Luke; Yang, Jian; Joshi, Giri; Meda, Lakshmikanth

    2015-01-01

    Highlights: • A thermoelectric generator (TEG) is fabricated using nanostructured half-Heusler materials. • The TE unicouple devices produce superior power density above 5 W/cm"2. • A TEG system with over 1 kW power output is demonstrated by recovering automotive waste heat. - Abstract: Given increasing energy use as well as decreasing fossil fuel sources worldwide, it is no surprise that interest in promoting energy efficiency through waste heat recovery is also increasing. Thermoelectric generators (TEGs) are one of the most promising pathways for waste heat recovery. Despite recent thermoelectric efficiency improvement in nanostructured materials, a variety of challenges have nevertheless resulted in few demonstrations of these materials for large-scale waste heat recovery. Here we demonstrate a high-performance TEG by combining high-efficiency nanostructured bulk materials with a novel direct metal brazing process to increase the device operating temperature. A unicouple device generates a high power density of 5.26 W cm"−"2 with a 500 °C temperature difference between hot and cold sides. A 1 kW TEG system is experimentally demonstrated by recovering the exhaust waste heat from an automotive diesel engine. The TEG system operated with a 2.1% heat-to-electricity efficiency under the average temperature difference of 339 °C between the TEG hot- and cold-side surfaces at a 550 °C exhaust temperature. The high-performance TEG reported here open up opportunities to use TEGs for energy harvesting and power generation applications.

  13. High power electron cyclotron heating in ISX and ORMAK Upgrade at ORNL

    International Nuclear Information System (INIS)

    England, A.C.; Eldridge, O.C.; Marcus, F.B.; Sprott, J.C.; Namkung, W.; Wilgen, J.B.

    1976-05-01

    A phased program of plasma heating at the electron cyclotron frequency is proposed for the Oak Ridge tokamaks ISX and ORMAK Upgrade. The past history of the program of electron cyclotron heating (ECH) at ORNL on mirrors and in the ELMO Bumpy Torus has been successful. Future technological developments in the production of high power high frequency microwave tubes look promising at this time. The physics of wave propagation and particle heating are fairly well understood and indicate the viability of this technique. Studies on breakdown and on runaway electron reduction will provide useful information for larger machines. Recent experiments in the USSR on small tokamaks have shown that ECH is a viable heating technique. Providing that the microwave tubes become available, the engineering considerations suggest that the technique is practical and workable, based on present day technology

  14. Preliminary design study of an alternate heat source assembly for a Brayton isotope power system

    Science.gov (United States)

    Strumpf, H. J.

    1978-01-01

    Results are presented for a study of the preliminary design of an alternate heat source assembly (HSA) intended for use in the Brayton isotope power system (BIPS). The BIPS converts thermal energy emitted by a radioactive heat source into electrical energy by means of a closed Brayton cycle. A heat source heat exchanger configuration was selected and optimized. The design consists of a 10 turn helically wound Hastelloy X tube. Thermal analyses were performed for various operating conditions to ensure that post impact containment shell (PICS) temperatures remain within specified limits. These limits are essentially satisfied for all modes of operation except for the emergency cooling system for which the PICS temperatures are too high. Neon was found to be the best choice for a fill gas for auxiliary cooling system operation. Low cycle fatigue life, natural frequency, and dynamic loading requirements can be met with minor modifications to the existing HSA.

  15. Passive flow heat exchanger simulation for power generation from solar pond using thermoelectric generators

    Science.gov (United States)

    Baharin, Nuraida'Aadilia; Arzami, Amir Afiq; Singh, Baljit; Remeli, Muhammad Fairuz; Tan, Lippong; Oberoi, Amandeep

    2017-04-01

    In this study, a thermoelectric generator heat exchanger system was designed and simulated for electricity generation from solar pond. A thermoelectric generator heat exchanger was studied by using Computational Fluid Dynamics to simulate flow and heat transfer. A thermoelectric generator heat exchanger designed for passive in-pond flow used in solar pond for electrical power generation. A simple analysis simulation was developed to obtain the amount of electricity generated at different conditions for hot temperatures of a solar pond at different flow rates. Results indicated that the system is capable of producing electricity. This study and design provides an alternative way to generate electricity from solar pond in tropical countries like Malaysia for possible renewable energy applications.

  16. Waste-heat disposal from US geothermal power plants: An update

    Science.gov (United States)

    Robertson, R. C.

    1982-05-01

    Some of the more interesting and significant methods that are currently being studied in the US for reducing waste heat dissipation system costs and water consumption are: (1) allowing plant power output to vary with ambient conditions; (2) use of ammonia to transport waste heat from the turbine condenser to air-cooled coils; (3) development of a plastic-membrane type wet/dry tower; (4) marketing of steam turbines that can tolerate a wider range of back pressure; (5) use of circulating water storage to delay heat dissipation until more favorable conditions exist; (6) development of tubes with enhanced heat transfer surfaces to reduce condenser capital costs; and (7) use of evaporative condensers to reduce costs in binary cycles. Many of these projects involve large scale tests that are now fully installed and producing some preliminary data.

  17. Technical Design of Flexible Thin-Film Solar Heating Clothes with Switchable Output Power

    Directory of Open Access Journals (Sweden)

    Zhao Yu Xiao

    2016-01-01

    Full Text Available This research focuses on the research and development of thermal clothes through technical design, by adopting unique removable electronic equipment and applying carbon fiber material to thermal clothes against cold, so as to meet the requirements of active heating and passive warmth retention. Firstly, the specification of power supply system was determined in accordance with the requirements of power system, and the specification of charging system was determined according to the specification of power system. Then circuit system was designed and tested. Fianlly, the electronic device was configured on the clothes appropriately, so that it should be conforms to ergonomic principles, convenient and fast.

  18. Investigation of heat exchangers for energy conversion systems of megawatt-class space power plants

    Science.gov (United States)

    Ilmov, D. N.; Mamontov, Yu. N.; Skorohodov, A. S.; Smolyarov, V. A.; Filatov, N. I.

    2016-01-01

    The specifics of operation (high temperatures in excess of 1000 K and large pressure drops of several megapascals between "hot" and "cold" coolant paths) of heat exchangers in the closed circuit of a gasturbine power converter operating in accordance with the Brayton cycle with internal heat recovery are analyzed in the context of construction of space propulsion systems. The design of a heat-exchange matrix made from doubly convex stamped plates with a specific surface relief is proposed. This design offers the opportunity to construct heat exchangers with the required parameters (strength, rigidity, weight, and dimensions) for the given operating conditions. The diagram of the working area of a test bench is presented, and the experimental techniques are outlined. The results of experimental studies of heat exchange and flow regimes in the models of heat exchangers with matrices containing 50 and 300 plates for two pairs of coolants (gas-gas and gas-liquid) are detailed. A criterion equation for the Nusselt number in the range of Reynolds numbers from 200 to 20 000 is proposed. The coefficients of hydraulic resistance for each coolant path are determined as functions of the Reynolds number. It is noted that the pressure in the water path in the "gas-liquid" series of experiments remained almost constant. This suggests that no well-developed processes of vaporization occurred within this heat-exchange matrix design even when the temperature drop between gas and water was as large as tens or hundreds of degrees. The obtained results allow one to design flight heat exchangers for various space power plants.

  19. Heat pipe air preheater for gas-/oil-fired power plants

    International Nuclear Information System (INIS)

    Teixeira, D.P.

    1993-02-01

    With the rising costs of fuel, utilities are constantly looking for ways to improve the net plant heat rate of new and existing units. Significant heat rate improvements can be obtained by reducing the exit stack flue gas temperature. This project evaluated two technologies to reduce flue gas temperatures: heat pipes and liquid-coupled heat exchangers. The specific unit chosen for evaluating these systems was Pacific Gas ampersand Electric's 750 MW Moss Landing Power Plant, Unit 7. Both natural gas and low sulfur (0.5%) fuel oil are fired at this plant. Accordingly, the heat exchangers were required to operate on both fuels. This study investigated the heat recovery installation through the preliminary engineering level of detail. At the conclusion of this effort, the results indicated that neither concept was economically attractive for the retrofit situation involved. In addition, several major technical questions remained unresolved concerning the design of a single heat-exchange device capable of operating on gas (sulfur-free) and oil (sulfur-containing) environments over the full normal operating load range. While the technologies this study reviewed have been installed in actual power plant applications, the site-specific aspects of Moss Landing Unit 7 significantly influenced the estimated costs and performance of each alternative. Using more cost-effective and corrosion-resistant materials may help reduce costs. The following conditions would further enhance the viability of lowering exit gas temperatures: Higher capacity factors; rising fuel costs; greater use of sulfur-free fuels, such as natural gas; lower manufacturing costs for heat exchanger technologies; or new unit application

  20. Transient non-boiling heat transfer in a fuel rod bundle during accidental power excursions

    International Nuclear Information System (INIS)

    Bonaekdarzadeh, S.; Johannsen, K.; Ramm, H.

    1977-01-01

    The physical problem studied is the transient non-boiling heat transfer of a cylindrical fuel rod consisting of fuel, gap, and cladding to a steady, fully developed turbulent flow. The fuel pin is assumed to be located in the interior region of a subassembly with regular triangular or square arrangements. The turbulent velocity field as well as turbulent transport properties are specified as functions of the coordinates normal to the axial flow direction. The heat generation within the fuel may be specified as an arbitrary function of the three spatial coordinates and time. A digital computer program has been developed. On the basis of finite-difference techniques, to solve the governing partial differential equations with their associated subsidiary conditions. Results have been obtained for a series of exponential power transients of interest to safety of liquid-metal and water cooled nuclear reactors. The general physical features of transient convective heat transfer as explored by previous investigators have qualitatively been substantiated by the present analysis. Emphasis has been devoted to investigate the differences of heat-transfer (coefficient) results from multi-region analysis including a realistic fuel rod model and single-region analysis for the coolant region only. A comparison with the engineering relationships for turbulent liquid-metal cooling by Stein, which are an extension of the heat transfer coefficient concept to account for transient heat fluxes, clearly demonstrates that, at the parameters studied, Stein's approach tends to largely overestimate the convective heat transfer at early times

  1. Reducing Pumping Power in Hydronic Heating and Cooling Systems with Microencapsulated Phase Change Material Slurries

    Science.gov (United States)

    Karas, Kristoffer Jason

    Phase change materials (PCMs) are being used increasingly in a variety of thermal transfer and thermal storage applications. This thesis presents the results of a laboratory study into the feasibility of improving the performance of hydronic heating and cooling systems by adding microcapsules filled with a PCM to the water used as heat transport media in these systems. Microencapsulated PCMs (MPCMs) increase the heat carrying capacity of heat transport liquids by absorbing or releasing heat at a constant temperature through a change of phase. Three sequences of tests and their results are presented: 1) Thermal cycling tests conducted to determine the melting temperatures and extent of supercooling associated with the MPCMs tested. 2) Hydronic performance tests in which MPCM slurries were pumped through a fin-and-tube, air-to-liquid heat exchanger and their thermal transfer performance compared against that of ordinary water. 3) Mechanical stability tests in which MPCM slurries were pumped in a continuous loop in order to gauge the extent of rupture due to pumping. It is shown that slurries consisting of water and MPCMs ˜ 14-24 mum in diameter improve thermal performance and offer the potential for power savings in the form of reduced pumping requirements. In addition, it is shown that while slurries of MPCMs 2-5 mum in diameter appear to exhibit better mechanical stability than slurries of larger diameter MPCMs, the smaller MPCMs appear to reduce the thermal performance of air-to-liquid heat exchangers.

  2. Dual-cycle power plant with internal and external heating of a gas turbine circuit

    International Nuclear Information System (INIS)

    Strach, L.

    1976-01-01

    The present proposal, after a preceding invention by the same inventor, aims at making possible the increased use of gas turbines in nuclear and coal-fired power plants. This is to be achieved by bringing the temperature of the combustion easily from a maximum of 900 0 C, as may be supplied, e.g., by the cooling media of nuclear reactors, up to the 1,700 to 2,000 0 C required as inlet temperature for gas turbines, with the aid of a fossil-fired recuperator. In fossil and nuclear power plants, gas turbines will more and more substitute steam turbines which affect the environment because of their high waste-heat losses. In coal power plants, only that part of the coal will be gasified whose resulting gas causes internal combustion within the furnace, while the remaining part of the coal is used for external combustion in a tabular heater. In a nuclear power plant, undisturbed maximum generation of electric power is to be achieved, even at reactor outages and shutdown periods for refuelling and maintenance, by almost inertia-free increase of the fossil fuel supply to the furnace (provided an extension of the latter for the capacity of heating the combustion air from room temperature till 1,700 to 2,000 0 C). The hazard of ruptures in the primary heat exchanging system is very low, because it is operated with a relative pressure of nearly zero between reactor coolant and gas turbine circuit. (RW) [de

  3. Magnetic power conversion with machines containing full or porous wheel heat exchangers

    Science.gov (United States)

    Egolf, Peter W.; Kitanovski, Andrej; Diebold, Marc; Gonin, Cyrill; Vuarnoz, Didier

    2009-04-01

    A first part of the article contains a thermodynamic theory describing the temperature distribution in a Curie wheel. The occurring nonlinear ordinary differential equation has an analytical solution. If a Curie wheel is stabilized by levitation, it is named Palmy wheel. These wheels show a full structure, and because of this reason, their uptake of heat from a flame (Curie wheel) or by (solar) light absorption (Palmy wheel) only on the periphery of a cylinder is very limited. To improve the method, a modification of the principle by introducing a convective heat transport into a porous wheel is discussed. By this the power conversion rate from a heat flux to mechanical and electric power is very much increased. The second part of the article presents results of a theoretical/numerical study on the efficiencies of magnetic power conversion plants operating with porous wheels. Furthermore, these efficiencies—which are promising—are compared with those of existing power conversion plants, as e.g. geothermal binary cycle power plants.

  4. Magnetic power conversion with machines containing full or porous wheel heat exchangers

    International Nuclear Information System (INIS)

    Egolf, Peter W.; Kitanovski, Andrej; Diebold, Marc; Gonin, Cyrill; Vuarnoz, Didier

    2009-01-01

    A first part of the article contains a thermodynamic theory describing the temperature distribution in a Curie wheel. The occurring nonlinear ordinary differential equation has an analytical solution. If a Curie wheel is stabilized by levitation, it is named Palmy wheel. These wheels show a full structure, and because of this reason, their uptake of heat from a flame (Curie wheel) or by (solar) light absorption (Palmy wheel) only on the periphery of a cylinder is very limited. To improve the method, a modification of the principle by introducing a convective heat transport into a porous wheel is discussed. By this the power conversion rate from a heat flux to mechanical and electric power is very much increased. The second part of the article presents results of a theoretical/numerical study on the efficiencies of magnetic power conversion plants operating with porous wheels. Furthermore, these efficiencies-which are promising-are compared with those of existing power conversion plants, as e.g. geothermal binary cycle power plants

  5. Thermoelectric Power Generation Utilizing the Waste Heat from a Biomass Boiler

    Science.gov (United States)

    Brazdil, Marian; Pospisil, Jiri

    2013-07-01

    The objective of the presented work is to test the possibility of using thermoelectric power to convert flue gas waste heat from a small-scale domestic pellet boiler, and to assess the influence of a thermoelectric generator on its function. A prototype of the generator, able to be connected to an existing device, was designed, constructed, and tested. The performance of the generator as well as the impact of the generator on the operation of the boiler was investigated under various operating conditions. The boiler gained auxiliary power and could become a combined heat and power unit allowing self-sufficient operation. The created unit represents an independent source of electricity with effective use of fuel.

  6. Micro-tubular flame-assisted fuel cells for micro-combined heat and power systems

    Science.gov (United States)

    Milcarek, Ryan J.; Wang, Kang; Falkenstein-Smith, Ryan L.; Ahn, Jeongmin

    2016-02-01

    Currently the role of fuel cells in future power generation is being examined, tested and discussed. However, implementing systems is more difficult because of sealing challenges, slow start-up and complex thermal management and fuel processing. A novel furnace system with a flame-assisted fuel cell is proposed that combines the thermal management and fuel processing systems by utilizing fuel-rich combustion. In addition, the flame-assisted fuel cell furnace is a micro-combined heat and power system, which can produce electricity for homes or businesses, providing resilience during power disruption while still providing heat. A micro-tubular solid oxide fuel cell achieves a significant performance of 430 mW cm-2 operating in a model fuel-rich exhaust stream.

  7. Accounting of the Power Balance for Neutral-beam heated H-Mode Plasmas in NSTX

    International Nuclear Information System (INIS)

    Paul, S.F.; Maingi, R.; Soukhanovskii, V.; Kaye, S.M.; Kugel, H.

    2004-01-01

    A survey of the dependence of power balance on input power, shape, and plasma current was conducted for neutral-beam-heated plasmas in the National Spherical Torus Experiment (NSTX). Measurements of heat to the divertor strike plates and divertor and core radiation were taken over a wide range of plasma conditions. The different conditions were obtained by inducing a L-mode to H-mode transition, changing the divertor configuration [lower single null (LSN) vs. double-null (DND)] and conducting a NBI power scan in H-mode. 60-70% of the net input power is accounted for in the LSN discharges with 20% of power lost as fast ions, 30-45% incident on the divertor plates, up to 10% radiated in the core, and about 12% radiated in the divertor. In contrast, the power accountability in DND is 85-90%. A comparison of DND and LSN data show that the remaining power in the LSN is likely to be directed to the upper divertor

  8. Performance analysis and comparison of an Atkinson cycle coupled to variable temperature heat reservoirs under maximum power and maximum power density conditions

    International Nuclear Information System (INIS)

    Wang, P.-Y.; Hou, S.-S.

    2005-01-01

    In this paper, performance analysis and comparison based on the maximum power and maximum power density conditions have been conducted for an Atkinson cycle coupled to variable temperature heat reservoirs. The Atkinson cycle is internally reversible but externally irreversible, since there is external irreversibility of heat transfer during the processes of constant volume heat addition and constant pressure heat rejection. This study is based purely on classical thermodynamic analysis methodology. It should be especially emphasized that all the results and conclusions are based on classical thermodynamics. The power density, defined as the ratio of power output to maximum specific volume in the cycle, is taken as the optimization objective because it considers the effects of engine size as related to investment cost. The results show that an engine design based on maximum power density with constant effectiveness of the hot and cold side heat exchangers or constant inlet temperature ratio of the heat reservoirs will have smaller size but higher efficiency, compression ratio, expansion ratio and maximum temperature than one based on maximum power. From the view points of engine size and thermal efficiency, an engine design based on maximum power density is better than one based on maximum power conditions. However, due to the higher compression ratio and maximum temperature in the cycle, an engine design based on maximum power density conditions requires tougher materials for engine construction than one based on maximum power conditions

  9. Minimization of the external heating power by long fusion power rise-up time for self-ignition access in the helical reactor FFHR2m

    International Nuclear Information System (INIS)

    Mitarai, O.; Sagara, A.; Chikaraishi, H.; Imagawa, S.; Shishkin, A.A.; Motojima, O.

    2006-10-01

    Minimization of the external heating power to access self-ignition is advantageous to increase the reactor design flexibility and to reduce the capital and operating costs of the plasma heating device in a helical reactor. In this work we have discovered that a larger density limit leads to a smaller value of the required confinement enhancement factor, lower density limit margin reduces the external heating power, and over 300 s of the fusion power rise-up time makes it possible to reach a minimized heating power. While the fusion power rise-up time in a tokamak is limited by the OH transformer flux or the current drive capability, any fusion power rise-up time can be employed in a helical reactor for reducing the thermal stresses of the blanket and shields, because the confinement field is generated by the external helical coils. (author)

  10. Balance-of-plant options for the Heat-Pipe Power System

    International Nuclear Information System (INIS)

    Berte, M.; Capell, B.

    1997-09-01

    The Heat-Pipe Power System (HPS) is a near-term, low-cost space fission power system with the potential for utilizing various option for balance-of-plant options. The following options have been studied: a low-power thermoelectric design (14-kWe output), a small Brayton cycle system (60--75 kWe), and a large Brayton cycle system (250 kWe). These systems were analyzed on a preliminary basis, including mass, volume, and structure calculations. These analyses have shown that the HPS system can provide power outputs from 10--250 kWe with specific powers of ∼ 14 W/kg for a 14-kWe model to ∼ 100 W/kg for a 250-kWe model. The system designs considered in this study utilize a common component base to permit easy expansion and development

  11. Thermal performance of a PCB embedded pulsating heat pipe for power electronics applications

    International Nuclear Information System (INIS)

    Kearney, Daniel J.; Suleman, Omar; Griffin, Justin; Mavrakis, Georgios

    2016-01-01

    Highlights: • Planar, compact PCB embedded pulsating heat pipe for heat spreading applications. • Embedded heat pipe operates at sub-ambient pressure with environmentally. • Compatible fluids. • Range of optimum operating conditions, orientations and fill ratios identified. - Abstract: Low voltage power electronics applications (<1.2 kV) are pushing the design envelope towards increased functionality, better reliability, low profile and reduced cost. One packaging method to enable these constraints is the integration of active power electronic devices into the printed circuit board improving electrical and thermal performance. This development requires a reliable passive thermal management solution to mitigate hot spots due to the increased heat flux density. To this end, a 44 channel open looped pulsating heat pipe (OL-PHP) is experimentally investigated for two independent dielectric working fluids – Novec"T"M 649 and Novec"T"M 774 – due to their lower pressure operation and low global warming potential compared to traditional two-phase coolants. The OL-PHP is investigated in vertical (90°) orientation with fill ratios ranging from 0.30 to 0.70. The results highlight the steady state operating conditions for each working fluid with instantaneous plots of pressure, temperature, and thermal resistance; the minimum potential bulk thermal resistance for each fill ratio and the effective thermal conductivity achievable for the OL-PHP.

  12. A multi-lateral trading model for coupled gas-heat-power energy networks

    International Nuclear Information System (INIS)

    Chen, Yue; Wei, Wei; Liu, Feng; Mei, Shengwei

    2017-01-01

    Highlights: •Optimal energy flows in the gas, heat, and power systems are modeled in detail. •A multi-lateral trading model for the coupled energy markets is proposed. •A two-phase algorithm for computing the market equilibrium. •Case studies demonstrate that market competition pilots reasonable energy prices. -- Abstract: The proliferation of cogeneration technology and the need for more resilient energy utilization inspire the emerging trend of integration of multi-resource energy systems, in which natural gas, heat, and electricity are produced, delivered, converted, and distributed more efficiently and flexibly. The increasing interactions and interdependencies across heterogenous physical networks impose remarkable challenges on the operation and market organization. This paper envisions the market trading scheme in the network-coupled natural gas system, district heating system, and power system. Based on the physical energy flow models of each system and their interdependency, a multi-lateral trading gas-heat-power (MLT-GHP) model is suggested, and a mixed-integer linear programming based two-phase algorithm is developed to find the market equilibrium. Case studies on two testing systems demonstrate the effectiveness of the proposed model and method, showing that the multi-lateral trading essentially results in market competition that orientates reasonable energy prices. Some prospects for future researches are also summarized.

  13. Technical and economical prerequisites of special district-heating nuclear power plant development

    International Nuclear Information System (INIS)

    Baturov, B.B.; Boldyrev, V.M.; Losev, V.L.; Sigal, M.V.

    1983-01-01

    Results are presented of technical and economical analysis of advisability of constructing combined Nuclear Power and Heating Plants (NPHP) assuring the possibility of their location near the areas of heat power consumption in case of observing a given degree of radiation safety for population and personnel. Specific features determining the choice of turbine-driven units for such plants are analyzed. Conditions of competiveness of a specialized NPHP with alternative power units, NPHP based on the WWER-1000 reactor and district heating plants (NDHP), are determined. Analysis of design specifications of NPHP with two VK-500 reactor units and structures of capital investments in such a plant reveal that an increase in the total capital investments in the NPHP would not exceed 2% with account of the difference in costs for grid heaters and a corresponding change in dimensions of operation rooms as well as changes in costs of heat removal system (within one site) at the TK turbine replacement by the T turbine

  14. Opportunities for biomass-derived 'bio-oil' in European heat and power markets

    International Nuclear Information System (INIS)

    Brammer, J.G.; Lauer, M.; Bridgwater, A.V.

    2006-01-01

    Bio-oil (biomass fast pyrolysis) systems for heat, power or CHP production are nearing demonstration status. Their commercial attractiveness will depend on many factors, and will vary with the application, the scale, and importantly the location and its associated economic and logistical factors. The objective of this work, carried out as part of an EC-ALTENER project, was to evaluate the opportunities for bio-oil in the heat and power markets of Europe. Bio-oil applications were compared with conventional (fossil) alternatives for the same heat and power duty. The evaluation was carried out by a quantitative assessment of the economic competitiveness of standard applications in 14 European countries. Location-specific data were collected, and combined with technology-specific data obtained from earlier work. A competitiveness factor (c F ) was derived which represents the total annual cost of a conventional alternative relative to a bio-oil application. The results showed a wide variation across Europe. A total of six countries had at least one bio-oil application which was economically competitive. Heat-only applications were found to be the most economically competitive, followed by CHP applications, with electricity-only applications only very rarely competitive. For a given technology, the larger the scale, the better the competitiveness

  15. Opportunities for biomass-derived 'bio-oil' in European heat and power markets

    International Nuclear Information System (INIS)

    Brammer, J.G.; Bridgwater, A.V.

    2006-01-01

    Bio-oil (biomass fast pyrolysis) systems for heat, power or CHP production are nearing demonstration status. Their commercial attractiveness will depend on many factors, and will vary with the application, the scale, and importantly the location and its associated economic and logistical factors. The objective of this work, carried out as part of an EC-ALTENER project, was to evaluate the opportunities for bio-oil in the heat and power markets of Europe. Bio-oil applications were compared with conventional (fossil) alternatives for the same heat and power duty. The evaluation was carried out by a quantitative assessment of the economic competitiveness of standard applications in 14 European countries. Location-specific data were collected, and combined with technology-specific data obtained from earlier work. A competitiveness factor (c F ) was derived which represents the total annual cost of a conventional alternative relative to a bio-oil application. The results showed a wide variation across Europe. A total of six countries had at least one bio-oil application which was economically competitive. Heat-only applications were found to be the most economically competitive, followed by CHP applications, with electricity-only applications only very rarely competitive. For a given technology, the larger the scale, the better the competitiveness. (author)

  16. Sizing Combined Heat and Power Units and Domestic Building Energy Cost Optimisation

    Directory of Open Access Journals (Sweden)

    Dongmin Yu

    2017-06-01

    Full Text Available Many combined heat and power (CHP units have been installed in domestic buildings to increase energy efficiency and reduce energy costs. However, inappropriate sizing of a CHP may actually increase energy costs and reduce energy efficiency. Moreover, the high manufacturing cost of batteries makes batteries less affordable. Therefore, this paper will attempt to size the capacity of CHP and optimise daily energy costs for a domestic building with only CHP installed. In this paper, electricity and heat loads are firstly used as sizing criteria in finding the best capacities of different types of CHP with the help of the maximum rectangle (MR method. Subsequently, the genetic algorithm (GA will be used to optimise the daily energy costs of the different cases. Then, heat and electricity loads are jointly considered for sizing different types of CHP and for optimising the daily energy costs through the GA method. The optimisation results show that the GA sizing method gives a higher average daily energy cost saving, which is 13% reduction compared to a building without installing CHP. However, to achieve this, there will be about 3% energy efficiency reduction and 7% input power to rated power ratio reduction compared to using the MR method and heat demand in sizing CHP.

  17. Performance demonstration of a high-power space-reactor heat-pipe design

    International Nuclear Information System (INIS)

    Merrigan, M.A.; Martinez, E.H.; Keddy, E.S.; Runyan, J.; Kemme, J.E.

    1983-01-01

    Performance of a 15.9-mm diam, 2-m long, artery heat pipe has been demonstrated at power levels to 22.6 kW and temperatures to 1500 0 K. The heat pipe employed lithium as a working fluid with distribution wicks and arteries fabricated from 400 mesh Mo-41 wt % Re screen. Molybdenum alloy (TZM) was used for the container. Peak axial power density attained in the testing was 19 kW/cm 2 at 1465 0 K. The corresponding radial flux density in the evaporator region of the heat pipe was 150 W/cm 2 . The extrapolated limit for the heat pipe at its 1500 0 K design point is 30 kW, corresponding to an axial flux density of 25 kW/cm 2 . Sonic and capillary limits for the design were investigated in the 1100 to 1500 0 K temperature range. Excellent agreement of measured and predicted temperature and power levels was observed

  18. Space and Terrestrial Power System Integration Optimization Code BRMAPS for Gas Turbine Space Power Plants With Nuclear Reactor Heat Sources

    Science.gov (United States)

    Juhasz, Albert J.

    2007-01-01

    In view of the difficult times the US and global economies are experiencing today, funds for the development of advanced fission reactors nuclear power systems for space propulsion and planetary surface applications are currently not available. However, according to the Energy Policy Act of 2005 the U.S. needs to invest in developing fission reactor technology for ground based terrestrial power plants. Such plants would make a significant contribution toward drastic reduction of worldwide greenhouse gas emissions and associated global warming. To accomplish this goal the Next Generation Nuclear Plant Project (NGNP) has been established by DOE under the Generation IV Nuclear Systems Initiative. Idaho National Laboratory (INL) was designated as the lead in the development of VHTR (Very High Temperature Reactor) and HTGR (High Temperature Gas Reactor) technology to be integrated with MMW (multi-megawatt) helium gas turbine driven electric power AC generators. However, the advantages of transmitting power in high voltage DC form over large distances are also explored in the seminar lecture series. As an attractive alternate heat source the Liquid Fluoride Reactor (LFR), pioneered at ORNL (Oak Ridge National Laboratory) in the mid 1960's, would offer much higher energy yields than current nuclear plants by using an inherently safe energy conversion scheme based on the Thorium --> U233 fuel cycle and a fission process with a negative temperature coefficient of reactivity. The power plants are to be sized to meet electric power demand during peak periods and also for providing thermal energy for hydrogen (H2) production during "off peak" periods. This approach will both supply electric power by using environmentally clean nuclear heat which does not generate green house gases, and also provide a clean fuel H2 for the future, when, due to increased global demand and the decline in discovering new deposits, our supply of liquid fossil fuels will have been used up. This is

  19. Maximum Efficiency of Thermoelectric Heat Conversion in High-Temperature Power Devices

    Directory of Open Access Journals (Sweden)

    V. I. Khvesyuk

    2016-01-01

    Full Text Available Modern trends in development of aircraft engineering go with development of vehicles of the fifth generation. The features of aircrafts of the fifth generation are motivation to use new high-performance systems of onboard power supply. The operating temperature of the outer walls of engines is of 800–1000 K. This corresponds to radiation heat flux of 10 kW/m2 . The thermal energy including radiation of the engine wall may potentially be converted into electricity. The main objective of this paper is to analyze if it is possible to use a high efficiency thermoelectric conversion of heat into electricity. The paper considers issues such as working processes, choice of materials, and optimization of thermoelectric conversion. It presents the analysis results of operating conditions of thermoelectric generator (TEG used in advanced hightemperature power devices. A high-temperature heat source is a favorable factor for the thermoelectric conversion of heat. It is shown that for existing thermoelectric materials a theoretical conversion efficiency can reach the level of 15–20% at temperatures up to 1500 K and available values of Ioffe parameter being ZT = 2–3 (Z is figure of merit, T is temperature. To ensure temperature regime and high efficiency thermoelectric conversion simultaneously it is necessary to have a certain match between TEG power, temperature of hot and cold surfaces, and heat transfer coefficient of the cooling system. The paper discusses a concept of radiation absorber on the TEG hot surface. The analysis has demonstrated a number of potentialities for highly efficient conversion through using the TEG in high-temperature power devices. This work has been implemented under support of the Ministry of Education and Science of the Russian Federation; project No. 1145 (the programme “Organization of Research Engineering Activities”.

  20. A Comparison of Coolant Options for Brayton Power Conversion Heat Rejection Systems

    International Nuclear Information System (INIS)

    Siamidis, John; Mason, Lee

    2006-01-01

    This paper describes potential heat rejection design concepts for Brayton power conversion systems. Brayton conversion systems are currently under study by NASA for Nuclear Electric Propulsion (NEP) and surface power applications. The Brayton Heat Rejection Subsystem (HRS) must dissipate waste heat generated by the power conversion system due to inefficiencies in the thermal-to-electric conversion process. Sodium potassium (NaK) and H2O are two coolant working fluids that have been investigated in the design of a pumped loop and heat pipe space HRS. In general NaK systems are high temperature (300 to 1000 K) low pressure systems, and H2O systems are low temperature (300 to 600 K) high pressure systems. NaK is an alkali metal with health and safety hazards that require special handling procedures. On the other hand, H2O is a common fluid, with no health hazards and no special handling procedures. This paper compares NaK and H2O for the HRS pumped loop coolant working fluid. A detailed excel analytical model, HRS O pt, was developed to evaluate the various HRS design parameters. It is capable of analyzing NaK or H2O coolant, parallel or series flow configurations, and numerous combinations of other key parameters (heat pipe spacing, diameter and radial flux, radiator facesheet thickness, fluid duct system pressure drop, system rejected power, etc.) of the HRS. This paper compares NaK against water for the HRS coolant working fluid with respect to the relative mass, performance, design and implementation issues between the two fluids