WorldWideScience

Sample records for central heating plants

  1. The Marstal Central Solar Heating Plant

    DEFF Research Database (Denmark)

    Heller, Alfred; Jochen, Dahm

    1999-01-01

    The central solar heating plant in Marstal is running since 1996 and has been monitored since. The resulting data from the plant is analysed and the plant performance evaluated. A TRNSYS-model (computersimulation) id prepared and validated based on the measured data from the plant. Acceptable good...

  2. Central solar heating plants with seasonal storage

    Energy Technology Data Exchange (ETDEWEB)

    Breger, D.S.; Sunderland, J.E.

    1989-03-01

    The University of Massachusetts has recently started a two year effort to identify and design a significant Central Solar Heating Plant with Seasonal Storage (CSHPSS) in Massachusetts. The work is closely associated with the U.S. participation in the International Energy Agency (IEA) Task on CSHPSS. The University is working closely with the Commonwealth of Massachusetts to assist in identifying State facilities as potential sites and to explore and secure State support which will be essential for product development after the design phase. Currently, the primary site is the University of Massachusetts, Amherst campus with particular interest in several large buildings which are funded for construction over the next 4-5 years. Seasonal thermal energy storage will utilize one of several geological formations.

  3. Optimisation of Control Strategy at the Central Solar Heating Plant in Marstal, Denmark

    DEFF Research Database (Denmark)

    Heller, Alfred

    1999-01-01

    The central solar heating plant at Marstal is monitored since 1996. The data is analysed with focus on the applied constrol strategy for the solar collector field. Variable flow is applied which is not the case at the other plants compared. The project analysed the performance, compared the...

  4. Floating atomic central heating-and-power plant converted from a strategic submarine

    International Nuclear Information System (INIS)

    In accordance with open-quotes The Treaty on the Reduction of Strategic Offensive Armsclose quotes signed in July 1991, the operations envisages by open-quotes The Procedures for elimination of SSBN's Launchersclose quotes should be accomplished at submarines of the second generation both by eliminating missile compartments together with launchers and by removal of launchers only from missile compartments. THe number of such ships could reach 30 units as has been forecasted for the year of 1998 inclusive. With regard to the fact that the remaining operation life of the main power plant equipment of a nuclear submarine decommissioned in accordance with the Treaty is about 50 per cent, potentially there is a possibility to convert them into floating atomic central heating-and-power plants. The latter variant envisaged in the open-quotes Procedures...close quotes is preferable for developing a floating plant based on ships decommissioned from the Navy, since it permits to remove launchers without cutting and subsequent connection of main cables, pipelines and systems which provide the control of the main power plant, nuclear safety, radiological safety, damage control and fire safety of the floating plant. A submarine could be delivered for refitting into a floating plant only after accomplishing the works envisaged by the open-quotes Procedures...close quotes

  5. Radiation hygienic assessment of centralized heat and hot water supply of Bilibino village from Bilibin central nuclear heating- and power plant

    International Nuclear Information System (INIS)

    The experience in using an atomic power plant for heat and hot water supply of the village of Bilibino is outlined. Particular attention is given to the population radiation safety. It has been demonstrated that radiation safety of the system is ensured by maintaining fixed pressure levels in the heating media and by the hermetic state of heat exchanges. Water in the heat and hot water supply network meets the requirements for drinking water. Radioactive corrosion products were not detected in the test water. Gamma-radiation dose rate from the surface of heating devices and pipe-lines in the test premises did not exceed the natural background, that is, U.U1-0.025 mrad

  6. Theoretical and experimental investigation of a Moving Bed Heat Exchanger for Solar Central Receiver Power Plants

    International Nuclear Information System (INIS)

    A Moving Bed Heat Exchanger for heat extraction from solar heated granular materials is investigated with respect to flow behaviour. To overcome limitations of existing empirical models, a numerical CFD model is established and parametrised with the help of experiments. Parametric studies are performed to quantify the effect of inlet velocities on the velocity field. A good agreement with an empirical model is found. Also, a comparison with PIV measurements confirms its validity, making it a solid basis for future design work.

  7. Preliminary design study of a central solar heating plant with seasonal storage at the University of Massachusetts, Amherst

    Science.gov (United States)

    Breger, D. S.; Sunderland, J. E.

    1991-04-01

    This report documents the design development and selection of the final preliminary design of a Central Solar Heating Plant with Seasonal Storage (CSHPSS) for the University of Massachusetts in Amherst (UMass). The effort has been performed by the Department of Mechanical Engineering at UMass under contract with the U.S. Department of Energy. Phase 1 of this project was directed at site selection for the CSHPSS project and was reported earlier. This report focuses on the Phase 2 development of the site conditions and analytical study of project design, performance, and cost. The UMass site presents an excellent opportunity of a CSHPSS project in terms of land availability for a large collector array, a 100 foot deep deposit of soft, saturated clay for seasonal thermal energy storage, and appropriate low temperature heating loads. The project under study represents the first implementation of this solar technology in the United States and results from the International Energy Agency collaboration on CSHPSS since 1979. The preliminary design calls for a large 10,000 m(exp 2) parabolic trough collector array, 70,000 m(exp 3) storage volume in clay with heat transfer through 900 boreholes. Design optimization is based on computer simulations using MINSUN and TRNSYS. The design is expected to provide 95 percent of the 3500 MWh heating and hot water load. A project cost of $3.12 million (plus $240,000 for HVAC load retrofit) is estimated, which provides an annualized cost of $66.2/MWh per unit solar energy delivered. The project will proceed into an engineering phase in Spring 1991.

  8. Essent and Ineos realize flexible combined heat and power generating plant; Essent en Ineos realiseren flexibele WKK-centrale

    Energy Technology Data Exchange (ETDEWEB)

    De Groote, Y.

    2008-07-01

    At the Dutch company Ineos Ozide in Zwijndrecht a new combined heat and power plant is supplying steam, electricity and water to various companies at the location since early this year. Due to increased capacity and improved reliability, the location can continue to expand. [mk]. [Dutch] Bij het bedrijf Ineos Oxide in Zwijndrecht levert een nieuwe warmtekrachtcentrale sinds begin dit jaar stoom, elektriciteit en water aan de diverse bedrijven op het terrein. Met de verhoogde capaciteit en verbeterde betrouwbaarheid kan de locatie weer verder groeien.

  9. Expedient arrangement of newly constructed systems for centralized heat supply

    Science.gov (United States)

    Zeigarnik, Yu. A.; Rotinov, A. G.

    2008-11-01

    It is shown that for newly constructed combined-cycle cogeneration plants and nuclear cogeneration plants, the optimum arrangement of the centralized heat supply system is the combination of a cogeneration plant and a district heat-supply station (a boiler house).

  10. Biofuelled heating plants

    International Nuclear Information System (INIS)

    The purpose of this report is to serve as a basis to enable establishment and operation of small and medium-sized bio-fuel plants, district heating plants and local district heating plants. Furthermore, the purpose of this report is to serve as a guideline and basis when realizing projects, from the first concept to established plant. Taking into account all the phases, from selection of heating system, fuel type, selection of technical solutions, authorization request or application to operate a plant, planning, construction and buying, inspection, performance test, take-over and control system of the plant. Another purpose of the report is to make sure that best available technology is used and to contribute to continuous development of the technology. The report deals mainly with bio-fuelled plants in the effect range 0.3 to10 MW. The term 'plant' refers to combined power and heating plants as well as 'simpler' district heating plants. The last-mentioned is also often referred to as 'local heating plant'. In this context, the term bio fuel refers to a wide range of fuel types. The term bio fuel includes processed fractions like powders, pellets, and briquettes along with unprocessed fractions, such as by-products from the forest industry; chips and bark. Bio fuels also include straw, energy crops and cereal waste products, but these have not been expressly studied in this report. The report is structured with appendixes regarding the various phases of the projects, with the purpose of serving as a helping handbook, or manual for new establishment, helping out with technical and administrative advice and environmental requirements. Plants of this size are already expanding considerably, and the need for guiding principles for design/technology and environmental requirements is great. These guiding principles should comply with the environmental legislation requirements, and must contain advice and recommendations for bio fuel plants in this effect range, also in

  11. Power and Efficiency Analysis of a Solar Central Receiver Combined Cycle Plant with a Small Particle Heat Exchanger Receiver

    Science.gov (United States)

    Virgen, Matthew Miguel

    Two significant goals in solar plant operation are lower cost and higher efficiencies. To achieve those goals, a combined cycle gas turbine (CCGT) system, which uses the hot gas turbine exhaust to produce superheated steam for a bottoming Rankine cycle by way of a heat recovery steam generator (HRSG), is investigated in this work. Building off of a previous gas turbine model created at the Combustion and Solar Energy Laboratory at SDSU, here are added the HRSG and steam turbine model, which had to handle significant change in the mass flow and temperature of air exiting the gas turbine due to varying solar input. A wide range of cases were run to explore options for maximizing both power and efficiency from the proposed CSP CCGT plant. Variable guide vanes (VGVs) were found in the earlier model to be an effective tool in providing operational flexibility to address the variable nature of solar input. Combined cycle efficiencies in the range of 50% were found to result from this plant configuration. However, a combustor inlet temperature (CIT) limit leads to two distinct Modes of operation, with a sharp drop in both plant efficiency and power occurring when the air flow through the receiver exceeded the CIT limit. This drawback can be partially addressed through strategic use of the VGVs. Since system response is fully established for the relevant range of solar input and variable guide vane angles, the System Advisor Model (SAM) from NREL can be used to find what the actual expected solar input would be over the course of the day, and plan accordingly. While the SAM software is not yet equipped to model a Brayton cycle cavity receiver, appropriate approximations were made in order to produce a suitable heliostat field to fit this system. Since the SPHER uses carbon nano-particles as the solar absorbers, questions of particle longevity and how the particles might affect the flame behavior in the combustor were addressed using the chemical kinetics software Chemkin

  12. Problem of heat pumps in central Russia

    International Nuclear Information System (INIS)

    This article describes the problems of heat pumps due to climatic conditions and the characteristics of energy sources. As energy sources for heat pumps, solar power, air, groundwater, soil, and rejected heat are considered. It is shown that in central Russia it is only rational to use waste heat as an energy source for heat pump systems. (author)

  13. 15 Years of R&D in Central Solar Heating in Denmark

    DEFF Research Database (Denmark)

    Heller, Alfred

    2000-01-01

    Danish R&D activities during the last two decades in the field of Central Solar Heating Plants and Thermal Energy Storage Technologies are presented. The most relevant central solar heating plants (CSHPs), with and without seasonal storage, are examined and essential experiences highlighted. The ...

  14. Emissions from small heating plants

    International Nuclear Information System (INIS)

    This study treats emissions from and economy of small biofuelled heating plants. In order to reduce emissions of particulates below 100 mg/nm3, the plants must be equipped with flue gas cleaning systems superior to cyclones/multicyclones. The use of pellets or pulverized fuel does not necessarily give emissions lower than 100 mg/nm3. However, the study shows that the CO-emissions can be kept low. An economic analysis for biofuelled plants is also presented 18 tabs, 18 figs

  15. Cleaning chemical and mechanical of heat exchangers in french nuclear plants; Limpieza mecanica y quimica de intercambiadores de calor en centrales nucleares francesas

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, J. t.; Guerra, P.; Carreres, C.

    2013-03-01

    This project was carried out under the frame of the approval of LAINSA as a supplier of EDF in France. The inspection performed on systems called the moisture separator reheaters (GSS) of CPO series reactor of EDF nuclear power plants has shown evidence of significant clogging due to deposits of magnetite inside the tubes of tube bundle. The pressure drop between inlet and outlet of the heating was close to maximum design criterion. This effect could result in equipment damage and loss of plant productivity. The aim of the work was the design, development, approval and implementation of a procedure for un blocking the tubes of the GSS respecting the integrity of materials and ensuring the harmlessness of cleaning procedures. The procedure used was to completely remove magnetite deposits in order to recover a passage diameter and a surface finish equivalent to the origin, thus avoiding the replacement of the GSS and obtaining a considerable reduction of costs. The achieve these objectives we have developed a procedure that is basically a mechanical pre-cleaning of all tubes of the GSS in order to unblock tem, followed by a chemical cleaning where magnetite is dissolved and crawled out of the tube bundle. The main results were: -Corrosion less than 10 microns. 100-110 Kg of magnetite removed by heat exchanger. -Final pressure drop similar to that of new equipment. -Waste water: 70 m{sup 3} per exchanger, which were managed by an authorized waste management company. This procedure has been applied successfully in 14 GSS type heat exchangers in Fessenheim and Bugey nuclear power plants in France between 2009 and 2011. This project demonstrates that the long experience of LAINSA in the Spanish nuclear industry along with the knowledge and experience in chemical cleaning of SOLARCA, have served to successfully work demanding and mature markets such as the French nuclear market, solving the problem of deposits of magnetite with an effective and safe method for the treated

  16. Study and modelling of underground water pollution in the region of large central heating-and-power plant in Eastern Czechia

    International Nuclear Information System (INIS)

    Regularities of underground water formation in one of hydrogeological regions in Eastern Czechia are considered. Analysis of long-term observation of ground water quality shows that it changed sufficiently in this region under the effect of permanent effluents of combustion products of heating-and-power plant and products of chemical reclamation of soils into atmosphere. The type of ground water changed from hydrocarbonate to sulfate. Results of model evaluation of pollution of surface air by sulfur dioxides correlate satisfactorily with data on real content of sulfates in ground water. 5 refs., 12 figs., 4 tabs

  17. Heat pipe central solar receiver. Volume I. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Bienert, W. B.; Wolf, D. A.

    1979-04-01

    The objective of this project was the conceptual design of a Central Solar Receiver Gas Turbine Plant which utilizes a high temperature heat pipe receiver. Technical and economic feasibility of such a plant was to be determined and preliminary overall cost estimates obtained. The second objective was the development of the necessary heat pipe technology to meet the requirements of this receiver. A heat pipe receiver is ideally suited for heating gases to high temperatures. The heat pipes are essentially loss free thermal diffusers which accept a high solar flux and transform it to a lower flux which is compatible with heat transferred to gases. The high flux capability reduces receiver heating surface, thereby reducing receiver heat losses. An open recuperative air cycle with a turbine inlet temperature of 816/sup 0/C (1500/sup 0/F) was chosen as the baseline design. This results in peak metal temperatures of about 870/sup 0/C (1600/sup 0/F). The receiver consists of nine modular panels which form the semicircular backwall of a cavity. Gas enters the panels at the bottom and exits from the top. Each panel carries 637 liquid metal heat pipes which are mounted at right angle to the gas flow. The evaporators of the heat pipes protrude from the flux absorbing front surface of the panels, and the finned condensors traverse the gas stream. Capital cost estimates were made for a 10 MW(e) pilot plant. The total projected costs, in mid-1978 dollars, range from $1,947 to $2,002 per electrical kilowatt. On the same basis, the cost of a water/steam solar plant is approximately 50% higher.

  18. Diffusion and dispersion heat of hydrotermal discharge from power plant; Difusion y dispersion de calor de la descarga hidrotermal de una central termoelectrica

    Energy Technology Data Exchange (ETDEWEB)

    Rendon Villalobos, J. Rodolfo

    1996-12-31

    This study describe the numerical simulation results of hydrodynamical behavior of the surface discharge cooling water to the sea incoming from the Tuxpan Power Plant under two different meteorological and oceanographic conditions; Case I, southwest variable winds average speeds of 3 m s-1 and Case II, northwest variable winds average speeds of 11.10 m s-1 . The numerical simulations were made using a three-dimensional model of coastal circulation and heat exchange. The statistical analysis of the wind speed and direction time series measured from January 1, 1981 to December 31, 1983, shows that the larger part of the winds were predominantly from 180 degrees to 315 degrees. Therefore, the southerly winds induce a sea surface circulation towards the north which move the discharged heat water away from the intake. On the contrary, the north winds drives the hydrothermal effluent towards the intake. Comparisons between the numerical simulation results and field data show that under different meteorological and oceanographic conditions, representative of the Tuxpan Site, the model correctly predicts the hydrothermal effluents surface diffusion and Dispersion measured on August 19-20 and 21, 1992 (Case I) and November 26, 1992 (Case II). The model predicts the extent of the impacted areas with cooling water with a precision of {+-} 11%. For all analyzed cases, the real size of the impacted areas that might have adverse effects on the marine ecosystems was not gibber than 0.1 km{sup 2}. Thus, these possible adverse effects are considered to be of local significance only. The simulated vertical profiles of temperature show that the cooling water discharged remains mostly o the surface of the receiving water mass and reaches a maximum depth of 3.5 m. This floatability if a consequence of the low density and small Froude number (Fr << 1), at the discharge, that characterizes the Tuxpan Power Plant Effluent. [Espanol] Este estudio describe los resultados de la simulacion

  19. Heating plant overcomes coal crisis

    International Nuclear Information System (INIS)

    At the last moment Kosice managed to overcome the threat of a more than 30-percent heating price increase. The biggest local heat producer, Teplaren Kosice, is running out of coal supplies. The only alternative would be gas, which is far more expensive. The reason for this situation was a dispute of the heating plant with one of its suppliers, Kimex. Some days ago, the dispute was settled and the heating plant is now expecting the first wagon loads of coal to arrive. These are eagerly awaited, as its supplies will not last for more than a month. It all started with a public tender for a coal supplier. Teplaren Kosice (TEKO) announced the tender for the delivery of 120,000 tons of coal in June. Kimex, one of the traditional and biggest suppliers, was disqualified in the course of the tender. The winners of the tender were Slovenergo, Bratislava and S-Plus Trade, Vranov nad Toplou. TEKO signed contracts with them but a district court in Kosice prohibited the company from purchasing coal from these contractors. Kimex filed a complaint claiming that it was disqualified unlawfully. Based on this the court issued a preliminary ruling prohibiting the purchase of coal from the winners of the tender. The heating plant had to wait for the final verdict. The problem was then solved by the company's new Board of Directors, who were appointed in mid October who managed to sign new contracts with the two winners and Kimex. The new contracts cover the purchase of 150-thousand tons of coal, which is 30,000 more than in the original tender specification. Each company will supply one third. (authors)

  20. Hybrid solar central receiver for combined cycle power plant

    Energy Technology Data Exchange (ETDEWEB)

    Bharathan, Desikan (Lakewood, CO); Bohn, Mark S. (Golden, CO); Williams, Thomas A. (Arvada, CO)

    1995-01-01

    A hybrid combined cycle power plant including a solar central receiver for receiving solar radiation and converting it to thermal energy. The power plant includes a molten salt heat transfer medium for transferring the thermal energy to an air heater. The air heater uses the thermal energy to preheat the air from the compressor of the gas cycle. The exhaust gases from the gas cycle are directed to a steam turbine for additional energy production.

  1. Hybrid solar central receiver for combined cycle power plant

    Science.gov (United States)

    Bharathan, D.; Bohn, M.S.; Williams, T.A.

    1995-05-23

    A hybrid combined cycle power plant is described including a solar central receiver for receiving solar radiation and converting it to thermal energy. The power plant includes a molten salt heat transfer medium for transferring the thermal energy to an air heater. The air heater uses the thermal energy to preheat the air from the compressor of the gas cycle. The exhaust gases from the gas cycle are directed to a steam turbine for additional energy production. 1 figure.

  2. Demand modelling for central heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Heller, A.

    2000-07-01

    Most researchers in the field of heat demand estimation have focussed on explaning the load for a given plant based on rather few measurements. This approach is simply the only one adaptable with the very limited data material and limited computer power. This way of dealing with the subject is here called the top-down approach, due to the fact that one tries to explain the load from the overall data. The results of such efforts are discussed in the report, leading to inspiration for own work. Also the significance of the findings to the causes for given heat loads are discussed and summarised. Contrary to the top-down approach applied in literature, a here-called bottom-up approach is applied in this work, describing the causes of a given partial load in detail and combining them to explain the total load for the system. Three partial load 'components' are discussed: 1) Space heating. 2) Hot-Water Consumption. 3) Heat losses in pipe networks. The report is aimed at giving an introduction to these subjects, but at the same time at collecting the previous work done by the author. Space heating is shortly discussed and loads are generated by an advanced simulation model. A hot water consumption model is presented and heat loads, generated by this model, utilised in the overall work. Heat loads due to heat losses in district heating a given a high priority in the current work. Hence a detailed presentation and overview of the subject is given to solar heating experts normally not dealing with district heating. Based on the 'partial' loads generated by the above-mentioned method, an overall load model is built in the computer simulation environment TRNSYS. The final tool is then employed for the generation of time series for heat demand, representing a district heating area. The results are compared to alternative methods for the generation of heat demand profiles. Results form this comparison will be presented. Computerised modelling of systems

  3. Plant heat zones of Mexico

    OpenAIRE

    L. E. Giddings; M. Soto-Esparza

    2005-01-01

    Se presenta un Mapa de Zonas de Calor para México equivalente al Plant Heat-Zone Map de los Estados Unidos de América (EEUU), el cual muestra el número de días promedio que en el año presentan temperatura máxima mayor a 30 °C (86 °F). Su uso principal es para evaluar el potencial para cultivar plantas ornamentales en un lugar dado, al igual que el mapa correspondiente de EEUU, preparado por la American Horticultural Society. También puede ser usado para determinar la distribución pot...

  4. Plants and the central nervous system.

    Science.gov (United States)

    Carlini, E A

    2003-06-01

    This review article draws the attention to the many species of plants possessing activity on the central nervous system (CNS). In fact, they cover the whole spectrum of central activity such as psychoanaleptic, psycholeptic and psychodysleptic effects, and several of these plants are currently used in therapeutics to treat human ailments. Among the psychoanaleptic (stimulant) plants, those utilized by human beings to reduce body weight [Ephedra spp. (Ma Huang), Paullinia spp. (guaraná), Catha edulis Forssk. (khat)] and plants used to improve general health conditions (plant adaptogens) were scrutinized. Many species of hallucinogenic (psychodysleptic) plants are used by humans throughout the world to achieve states of mind distortions; among those, a few have been used for therapeutic purposes, such as Cannabis sativa L., Tabernanthe iboga Baill. and the mixture of Psychotria viridis Ruiz and Pav. and Banisteriopsis caapi (Spruce ex Griseb.) C.V. Morton. Plants showing central psycholeptic activities, such as analgesic or anxiolytic actions (Passiflora incarnata L., Valeriana spp. and Piper methysticum G. Forst.), were also analysed.Finally, the use of crude or semipurified extracts of such plants instead of the active substances seemingly responsible for their therapeutic effect is discussed. PMID:12895668

  5. Heat Generation by Heat Pump for LNG Plants

    OpenAIRE

    Moe, Bjørn Kristian

    2011-01-01

    Abstract The LNG production plant processing natural gas from the Snøhvit field outside Hammerfest in northern Norway utilizes heat and power produced locally with gas turbines. Building a new production train supplied with electricity from the power grid is being evaluated as a possible solution for reducing CO2 emissions from the plant. Buying electricity from the grid rather than producing it in a combined heat and power plant makes it necessary to find new ways to cover the heat loads at ...

  6. Comparative ecobalancing accounting of semi-central house heat supply from wood residues

    International Nuclear Information System (INIS)

    In 2008 almost 40 percent of the German final energy demand was used for room heating and hot water supply. To decrease environmental burdens and to save fossil resources a restructuring of the heating sector is needed. Therefore legislation enforces higher insulation standards of buildings and a more frequent use of renewable energies as well as heating networks. Wood as a renewable and storable energy source is an attractive fuel. However, it must be used as efficiently as possible because of limited wood supplies. Connecting buildings via a heating network is a good option since bigger heating plants can operate at higher efficiencies than small heaters. However, the higher insulation standards of the buildings often oppose the construction of a heating network, because heating networks work best with high energy demands and low network lengths. Therefore the environmental and economic feasibility of new heating networks needs to be checked beforehand. This thesis explores the environmental burdens of different semi- centralized heating networks using wood residues as fuel. A semi- centralized heating network is a network with no more than 500 customers and a heating plant with less than 5 MWth. While wood residues are used in the base load plant, peak load is covered by a gas heating plant. As a method to analyze the potential environmental burdens of the heat supply a life cycle assessment according to ISO 14040/44 is used. Opposed to former life cycle assessment studies, construction and operation of the network is included in the assessment. Even though the environmental impacts of the semi- centralized heating from wood residues are dominated by the heat supply, an observation of the impacts solely at the heating plant is not sufficient. By varying the boundary conditions of the heating network two main contributors to the environmental impacts are found. In addition to the heat production at the plant the type of the buildings in the settlement has a huge

  7. Efficiency Analysis of Independent and Centralized Heating Systems for Residential Buildings in Northern Italy

    Directory of Open Access Journals (Sweden)

    Fabio Rinaldi

    2011-11-01

    Full Text Available The primary energy consumption in residential buildings is determined by the envelope thermal characteristics, air change, outside climatic data, users’ behaviour and the adopted heating system and its control. The new Italian regulations strongly suggest the installation of centralized boilers in renovated buildings with more than four apartments. This work aims to investigate the differences in primary energy consumption and efficiency among several independent and centralized heating systems installed in Northern Italy. The analysis is carried out through the following approach: firstly building heating loads are evaluated using the software TRNSYS® and, then, heating system performances are estimated through a simplified model based on the European Standard EN 15316. Several heating systems have been analyzed, evaluating: independent and centralized configurations, condensing and traditional boilers, radiator and radiant floor emitters and solar plant integration. The heating systems are applied to four buildings dating back to 2010, 2006, 1960s and 1930s. All the combinations of heating systems and buildings are analyzed in detail, evaluating efficiency and primary energy consumption. In most of the cases the choice between centralized and independent heating systems has minor effects on primary energy consumption, less than 3%: the introduction of condensing technology and the integration with solar heating plant can reduce energy consumption by 11% and 29%, respectively.

  8. Decentralized Heat Supply – Alternative to Centralized One

    OpenAIRE

    Nazarov, V; L. Tarasevich; А. Burov

    2014-01-01

    The paper presents a concrete example that shows comparative characteristics of decentralized and centralized heat supply. It has been shown in the paper that selection of this or that variant of heat supply significantly depends on losses in heat supply networks.

  9. Decentralized Heat Supply – Alternative to Centralized One

    Directory of Open Access Journals (Sweden)

    V. Nazarov

    2014-09-01

    Full Text Available The paper presents a concrete example that shows comparative characteristics of decentralized and centralized heat supply. It has been shown in the paper that selection of this or that variant of heat supply significantly depends on losses in heat supply networks.

  10. Automated heating plants: from theory to reality

    Energy Technology Data Exchange (ETDEWEB)

    Cassin, P. [Agence de l`Environnement et de la Maitrise de l`Energie, 75 - Paris (France)

    1993-12-31

    This paper deals with the role of Ademe (Agence de l`Environnement et de la Maitrise de l`Energie) and the situation after ten years of work. The establishment of automated heating plants in public buildings and local collectivities is one of the priorities of the Agency. From 1983 to 1993, 350 heating plants in housing have been set up, research teams have been constituted and a network of competent professionals has been organised. (TEC). 1 fig.

  11. NUCLEAR POWER PLANT WASTE HEAT HORTICULTURE

    Science.gov (United States)

    The report gives results of a study of the feasibility of using low grade (70 degrees F) waste heat from the condenser cooling water of the Vermont Yaknee nuclear plant for commercial food enhancement. The study addressed the possible impact of laws on the use of waste heat from ...

  12. Central receiver solar thermal power system, Phase 1. CDRL Item 2. Pilot plant preliminary design report. Volume V. Thermal storage subsystem. [Sensible heat storage using Caloria HT43 and mixture of gravel and sand

    Energy Technology Data Exchange (ETDEWEB)

    Hallet, Jr., R. W.; Gervais, R. L.

    1977-10-01

    The proposed 100-MWe Commercial Plant Thermal Storage System (TSS) employs sensible heat storage using dual liquid and solid media for the heat storage in each of four tanks, with the thermocline principle applied to provide high-temperature, extractable energy independent of the total energy stored. The 10-MW Pilot Plant employs a similar system except uses only a single tank. The high-temperature organic fluid Caloria HT43 and a rock mixture of river gravel and No. 6 silica sand were selected for heat storage in both systems. The system design, installation, performance testing, safety characteristics, and specifications are described in detail. (WHK)

  13. Detailed study of the heat sink of Saint-Laurent-des-Eaux nuclear plant; Etude detaillee de la source froide de la centrale de Saint-Laurent des Eaux

    Energy Technology Data Exchange (ETDEWEB)

    Audrerie, Y

    1997-12-31

    This work is dedicated to a detailed study of the reliability of the heat sink of the nuclear plant which is situated on the banks of the Loire river. In the first part the requirements the heat sink has to comply with are reviewed, in the second part the various operating modes, the different procedures established to cope with the hazards of the river: icing up, frost, overflow, lowest water, choking are reported. This analysis highlights the good compliance of the heat sink with the specifications but some improvements about periodic testing are proposed. (A.C.)

  14. EIR solar heating plant OASE

    International Nuclear Information System (INIS)

    For a corrosion surveillance program of the EIR solar heating unit, OASE, the coolant of the flat collector circuit is controlled and material samples mounted in a circuit by-pass are tested periodically. The results of the first year of surveillance have been evaluated and interpreted. Furthermore water-ethyleneglycol mixtures without and with corrosion inhibiting additives have been tested. Only the ethyleneglycol and inhibitor contents may be controlled by means of pH and electrical conductivity tests. The metal content in the coolant as a corrosion indicator is not recorded by pH or electrical conductivity readings - they must be determined by chemical analysis. Samples of different materials used in the coolant circuit, mounted in a test by-pass of the circuit and taken out every year for testing give information on the corrosion behaviour of these materials under service conditions. Corrosion can be prevented or reduced by adding inhibitors to the coolant. The optimum inhibitor composition for the concerned material combinations and for the coolant must be determined in laboratory tests. The inhibitor composition used in the flat collector circuit proved not to be the optimum: corrosion on the aluminium of the rollbond absorber plate was not prevented. (Auth.)

  15. 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

    Driving a ground source heat pump in a central heating system with the minimum power consumption is studied. The idea of control is based on the fact that, in a heat pump, the temperature of the forward water has a strong positive correlation with the consumed electric power by the compressor. Th...

  16. The design of future central receiver power plants based on lessons learned from the Solar One Pilot Plant

    Science.gov (United States)

    Kolb, G. J.

    The 10-MW(sub e) Solar One Pilot Plant was the world's largest solar central receiver power plant. During its power production years it delivered over 37,000 MWhrs (net) to the utility grid. In this type of electric power generating plant, large sun-tracking mirrors called heliostats reflect and concentrate sunlight onto a receiver mounted on top of a tower. The receiver transforms the solar energy into thermal energy that heats water, turning it into superheated steam that drives a turbine to generate electricity. The Solar One Pilot Plant successfully demonstrated the feasibility of generating electricity with a solar central receiver power plant. During the initial 2 years the plant was tested and 4 years the plant was operated as a power plant, a great deal of data was collected relating to the efficiency and reliability of the plant's various systems. This paper summarizes these statistics and compares them to goals developed by the U.S. Department of Energy. Based on this comparison, improvements in the design and operation of future central receiver plants are recommended. Research at Sandia National Laboratories and the U.S. utility industry suggests that the next generation of central receiver power plants will use a molten salt heat transfer fluid rather than water/steam. Sandia has recently completed the development of the hardware needed in a molten salt power plant. Use of this new technology is expected to solve many of the performance problems encountered at Solar One. Projections for the energy costs from these future central receiver plants are also presented. For reference, these projections are compared to the current energy costs from the SEGS parabolic trough plants now operating in Southern California.

  17. The design of future central receiver power plants based on lessons learned from the Solar One Pilot Plant

    Energy Technology Data Exchange (ETDEWEB)

    Kolb, G.J.

    1991-01-01

    The 10-MW{sub e} Solar One Pilot Plant was the world's largest solar central receiver power plant. During its power production years it delivered over 37,000 MWhrs (net) to the utility grid. In this type of electric power generating plant, large sun-tracking mirrors called heliostats reflect and concentrate sunlight onto a receiver mounted on top a of a tower. The receiver transforms the solar energy into thermal energy that heats water, turning it into superheated steam that drives a turbine to generate electricity. The Solar One Pilot Plant successfully demonstrated the feasibility of generating electricity with a solar central receiver power plant. During the initial 2 years the plant was tested and 4 years the plant was operated as a power plant, a great deal of data was collected relating to the efficiency and reliability of the plant's various systems. This paper summarizes these statistics and compares them to goals developed by the US Department of Energy. Based on this comparison, improvements in the design and operation of future central receiver plants are recommended. Research at Sandia National Laboratories and the US utility industry suggests that the next generation of central receiver power plants will use a molten salt heat transfer fluid rather than water/steam. Sandia has recently completed the development of the hardware needed in a molten salt power plant. Use of this new technology is expected to solve many of the performance problems encountered at Solar One. Projections for the energy costs from these future central receiver plants are also presented. For reference, these projections are compared to the current energy costs from the SEGS parabolic trough plants now operating in Southern California.

  18. Maintenance and service of heat pump plants

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, J.; Dirmeier, K.

    1983-02-01

    The utilization of heat pumps for layer plants (from ca. 150 kW upward) which is definitely efficient already today often fails because of insufficient maintenance services offered by the installing firms. The detailed practical information regarding maintenance is not to replace but to complete the service training usually offered by the manufacturers.

  19. Heat recovery from nuclear power plants

    International Nuclear Information System (INIS)

    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)

  20. ENERGY EFFICIENCY OF DIFFERENT WAYS OF CENTRAL HEATING

    Directory of Open Access Journals (Sweden)

    A. E. Piir

    2015-03-01

    Full Text Available  The article shows the calculation comparison of fuel for producing of heat-line water with a help of different technological installations, transforming (converting high-grade heat from burning process of fuel or in the process of non-reversible heat exchange with coolant (heating agent, or with a help of heat engines, which allow to decrease losses of working efficiency and thus to reduce the use of fuel. There were considered five types of plants beginning from the  simplest  one  up  to  the  most  complex  in  two  variants,  when  the  heat  exchangers and machines are perfect (ideal and when equipment has the known degree of efficiency (perfection:1 water-heat boiler station, working on organic fuel;2 electrical boiler station, obtaining energy on power transmission lines from condensing power station;3 line heater of TPP, obtaining steam from heating turbine;4 line heater CPP, powered by steam from pressure reducing unit;5 heat pump, producing energy on power supply lines from TPP.In this article were investigated three ideal reversible ways of transformation of   high- grade heat into low-grade heat with a help of decreasing and increasing and combined (suggested by the authors heat transformers and their thermodynamic equivalence was shown in this article. And there were suggested universal installation for electric energy generation, cold and heat of two grades for heat-water supply and the heating process on the base of gascompressors   gas turbines. These results are so important (actual for power engineers of the countries with  increasing consumption  of organic  fuel and  its enhancement in  value and realizing programs of energy saving .The analysis shows, that the quality of produced low-grade heat per unit of used high-grade heat for ideal plants (installations is: electrical boiler unit – 0.7;  water boiler unit – 1.0; for heat pump, heating turbine, combined heat transformers   – 4

  1. Status of PBMR process heat plant project

    International Nuclear Information System (INIS)

    Conventional nuclear power plants only supply energy in a portion of the electricity sector, while the transportation and industrial energy sectors remain to rely exclusively on fossil fuels for its energy needs. However, the transportation and industrial sectors are vast consumers of energy and jointly contribute to approximately 66% of global CO2 emissions. Industry concerns for escalating cost of natural gas and petroleum, energy security and environmental acceptability are driving interest in using nuclear energy as primary energy source for transportation and industrial applications. An opportunity exists to introduce nuclear process heat into the world's energy market, but to succeed any technology must be available commercially in the needed timeframe, be demonstrably safe in order to be located close to the process plant, be economical, match the process energy needs and must produce the required temperatures. The Pebble Bed Modular Reactor (PBMR), under development in South Africa, fits each of these requirements. The PBMR is an advanced helium-cooled, graphite-moderated High Temperature Gas-cooled Reactor (HTGR). A 400 MWt (165 MWe) Demonstration Power Plant (DPP) for the production of electricity is being developed in South Africa for its national utility Eskom. The DPP project is envisioned to form the platform to launch future commercial PBMR products, notably including a variety of process heat applications for the transport and industrial sectors. PBMR Company has partnered with the Shaw Group, Westinghouse and others to develop and pilot its nuclear process heat technology. The team proposes that the first demonstration facility involve a consortium of industrial clients and is currently working to that end. One of these collaborative projects includes the Westinghouse-led consortium that was awarded the principal contract for the initial phase of pre-conceptual engineering services and planning for the Next Generation Nuclear Plant (NGNP) by the U

  2. The Apatity nuclear heating plant project: modern technical and economic issues of nuclear heat application in Russia

    International Nuclear Information System (INIS)

    Traditionally Russia is a country with advanced structure of centralized heat supply. Many thermal plants and heating networks need technical upgrading to improve their technical and economic efficiency. Fossil fuelled heating capacities have a negative influence on ecology, which can be seen especially in the northern regions of Russia. Furthermore, fossil fuel prices are rising in Russia. The above factors tend to intensify the need for alternative heat sources being capable of solving the problem. Nuclear heat sources may be the alternative. In this paper, the main features of a proposed NHP in the Murmansk region are summarized. (author)

  3. Water-Source Heat Pump Air-Conditioning System Characteristic for Central Control Room in a Fossil Fuel Power Plants%火力发电厂集中控制室水源热泵空调系统设计特点

    Institute of Scientific and Technical Information of China (English)

    王明国; 卢柏春

    2016-01-01

    This article describes the water source heat pump air-conditioning system for central control room and electronic equipment room in Puqi Phase II Power Plant project and analyzes the design characteristic of the system. The Water source heat pump air-conditioning system has a broad application value.%介绍了蒲圻电厂二期工程的集控室及电子设备间的水源热泵空调系统,分析了该系统的设计特点,具有推广应用的价值。

  4. Negative heat capacities in central Xe+Sn reactions

    International Nuclear Information System (INIS)

    In this study the fluctuation method is applied to the 32-50 A.MeV Xe + Sn central collisions detected with the INDRA multidetector. This method based on kinetic energy fluctuations allows the authors to provide information on the liquid gas phase transition in nuclear multifragmentation. In the case of Xe + Sn central reactions a divergence in the total heat capacity is observed. This divergence corresponds to large fluctuations on the detected fragment partitions. A negative heat capacity branch is measured and so tends to confirm the observation of a first order phase transition in heavy-ion collisions. (A.C.)

  5. Negative heat capacities in central Xe+Sn reactions

    Energy Technology Data Exchange (ETDEWEB)

    Le Neindre, N.; Bougault, R.; Gulminelli, F. [Laboratoire de Physique Corpusculaire, IN2P3-CNRS, ISMRA et Universite, 14 - Caen (France)] [and others

    2000-02-01

    In this study the fluctuation method is applied to the 32-50 A.MeV Xe + Sn central collisions detected with the INDRA multidetector. This method based on kinetic energy fluctuations allows the authors to provide information on the liquid gas phase transition in nuclear multifragmentation. In the case of Xe + Sn central reactions a divergence in the total heat capacity is observed. This divergence corresponds to large fluctuations on the detected fragment partitions. A negative heat capacity branch is measured and so tends to confirm the observation of a first order phase transition in heavy-ion collisions. (A.C.)

  6. District heat generating plants - present planning and significant results

    International Nuclear Information System (INIS)

    Combined generation of electricity and heat is a must for economical generation of district heat for the base load range with a minimum environmental impact. More sophisticated desings are taking over both for heat extraction from condensing turbine power plants as well as for backpressure turbine power plants. More and more existing power plants are being backfitted for heat extraction. The advantages and disadvantages of the different concepts are illustrated. The possibilities for nuclear district heat generation are also touched on. (orig.)

  7. Dynamic instabilities in radiation-heated boiler tubes for solar central receivers

    Science.gov (United States)

    Wolf, S.; Chan, K. C.; Chen, K.; Yadigaroglu, G.

    1982-11-01

    Density-wave instabilities have been investigated in circumferentially nonuniform radiation-heated boiler tubes, simulating solar heating. Analysis and experimental data are presented. The analysis provides the basis for a computer code, STEAMFREQ-I, for the prediction of density-wave instabilities in boiler tubes with imposed heat flux. The key model features include a drift-flux flow model in the boiling region, spatial variation of heat flux, wall dynamics, and variable steam properties in the superheat region. The experimental data include results from two radiation heated boiler panel tests. The data are applicable to central receivers for solar electric power plants. Data for stable and unstable conditions are compared with predictions from STEAMFREQ-I.

  8. International seminar on biomass and fossil fuels co-firing in power plants and heating plants in Europe; Seminaire international sur la cocombustion de biomasse et d'energies fossiles dans les centrales electriques et les chaufferies en Europe

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The aim of the European commission which has fixed to 12% the share of renewable energies in the total energy consumption up to 2010, is to develop the biomass sector. Co-firing is a solution that allows to increase significantly the use of biomass because it does not require important investments. Today, about 150 power plants in Europe use co-firing. An Altener project named 'Cofiring' has ben settled in order to bring together and analyze the European experience in this domain and to sustain and rationalize the design of future projects. The conclusions of this study, coordinated by VTT Energy and which involves CARMEN (Germany), CBE (Portugal), the Danish centre for landscape and planning, ITEBE (France), KOBA (Italy), SLU (Sweden), and EVA (Austria), were presented during this international seminar. (J.S.)

  9. Heat power plants in the Federal Republic of Germany

    International Nuclear Information System (INIS)

    The construction of conventional power plants in the past years has been almost exclusively dominated by plants for the heat market. The technology of fluidised bed combustion has been successfully introduced due to its small space requirement, low toxic emissions and relatively low plant costs. Due to pollution legislation it is difficult for new, small heat power plants to produce district heat at competitive prices. At present district heat can only be economically generated by condensation power plants with heat decoupling. The authors elaborate on this technology. (orig.)

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

    International Nuclear Information System (INIS)

    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

  11. Woodfuel procurement strategies of district heating plants

    International Nuclear Information System (INIS)

    Woodfuel use in the Swedish district heating sector increased significantly from 1985 to 1999. This study analysed strategies and considerations concerning woodfuel procurement in district heating plants. Priorities and concerns in the industry involved an increased woodfuel share, ambitions to create an environmental image, cost minimisation, awareness about the role of energy policies for fuel choice, improvement of woodfuel quality and the ambition to maintain a competitive woodfuel market with several suppliers. Factor analysis yielded five dimensions in the woodfuel procurement strategies among the district heating companies: (1) increased woodfuel use; (2) import; (3) spot market woodfuel purchases; (4) focus on refined woodfuels; and (5) using price only when deciding whether to use woodfuels or other fuels. Five clusters were defined along the three strategy dimensions (1)-(3). The clusters differed concerning size, experiences from the introduction of woodfuels, perceptions about woodfuels and strategies employed to date. This paper describes different strategies that the district heating companies apply on the woodfuel market. The conclusion is that policies should consider this diversity in procurement strategies, mitigate their negative side-effects and assist to make them cost-effective. (author)

  12. Investigation of bubble behaviours in wet central heating systems

    OpenAIRE

    Shefik Ali; Ge Yunting

    2014-01-01

    A series of experimental measurements has been conducted in order to investigate the bubble behaviours through the horizontal pipe line of the domestic wet central heating systems. Obtained results exposed the effect of 90 degree bend, buoyancy forces on bubbly two phase flow patterns and effect of velocity on void fractions and bubble diameters. Distance chosen for the first sight glass (HSG0) was sufficient enough to note the effect of 90 degree bend on void fraction patterns. Due to the ef...

  13. Thermoeconomic optimization of a Kalina cycle for a central receiver concentrating solar power plant

    DEFF Research Database (Denmark)

    Modi, Anish; Kærn, Martin Ryhl; Andreasen, Jesper Graa;

    2016-01-01

    Concentrating solar power plants use a number of reflecting mirrors to focus and convert the incident solar energy to heat, and a power cycle to convert this heat into electricity. This paper evaluates the use of a high temperature Kalina cycle for a central receiver concentrating solar power plant...... and the economic perspectives, the results suggest that it is not beneficial to use the Kalina cycle for high temperature concentrating solar power plants....... with direct vapour generation and without storage. The use of the ammonia-water mixture as the power cycle working fluid with non-isothermal evaporation and condensation presents the potential to improve the overall performance of the plant. This however comes at a price of requiring larger heat exchangers...

  14. Layouts of trigeneration plants for centralized power supply

    Science.gov (United States)

    Klimenko, A. V.; Agababov, V. S.; Il'ina, I. P.; Rozhnatovskii, V. D.; Burmakina, A. V.

    2016-06-01

    One of the possible and, under certain conditions, sufficiently effective methods for reducing consumption of fuel and energy resources is the development of plants for combined generation of different kinds of energy. In the power industry of Russia, the facilities have become widespread in which the cogeneration technology, i.e., simultaneous generation of electric energy and heat, is implemented. Such facilities can use different plants, viz., gas- and steam-turbine plants and gas-reciprocating units. Cogeneration power supply can be further developed by simultaneously supplying the users not only with electricity and heat but also with cold. Such a technology is referred to as trigeneration. To produce electricity and heat, trigeneration plants can use the same facilities that are used in cogeneration, namely, gas-turbine plants, steam-turbine plants, and gas-reciprocating units. Cold can be produced in trigeneration plants using thermotransformers of various kinds, such as vaporcompression thermotransformers, air thermotransformers, and absorption thermotransformers, that operate as chilling machines. The thermotransformers can also be used in the trigeneration plants to generate heat. The main advantage of trigeneration plants based on gas-turbine plants or gas-reciprocating units over cogeneration plants is the increased thermodynamic power supply efficiency owing to utilization of the waste-gas heat not only in winter but also in summer. In the steam-turbine-based trigeneration plants equipped with absorption thermotransformers, the enhancement of the thermodynamic power supply efficiency is determined by the increase in the heat extraction load during the nonheating season. The article presents calculated results that demonstrate higher thermodynamic efficiency of a gas-turbine-based plant with an absorption thermotransformer that operates in the trigeneration mode compared with a cogeneration gas-turbine plant. The structural arrangements of trigeneration

  15. Dynamics in the Central Plant Cell Metabolism

    OpenAIRE

    Ampofo-Asiama, Jerry

    2014-01-01

    As part of their development, plants have acquired adaptive mechanisms to cope with different stress situations they encounter in their environment. These adaptive mechanisms include the ability to alter their metabolism when faced with extreme environmental conditions such as low oxygen. In higher plants, oxygen (O2) availability is important for energy production through respiratory metabolism. Under conditions where O2 becomes limiting, respiratory metabolism can be impeded leading to impa...

  16. Efficient Heat Use from Biogas CHP Plants. Case Studies from Biogas Plants in Latvia

    OpenAIRE

    Dzene, Ilze; Slotiņa, Lāsma

    2013-01-01

    This paper is focusing on efficient heat use from biogas plants. It gives an overview about various biogas heat use options and specifically addresses biogas heat use market in Latvia. In the end three examples from typical agricultural biogas plants in Latvia and their heat use plans are described.

  17. Cob biomass supply for combined heat and power and biofuel in the north central USA

    International Nuclear Information System (INIS)

    Corn (Zea mays L.) cobs are being evaluated as a potential bioenergy feedstock for combined heat and power generation (CHP) and conversion into a biofuel. The objective of this study was to determine corn cob availability in north central United States (Minnesota, North Dakota, and South Dakota) using existing corn grain ethanol plants as a proxy for possible future co-located cellulosic ethanol plants. Cob production estimates averaged 6.04 Tg and 8.87 Tg using a 40 km radius area and 80 km radius area, respectively, from existing corn grain ethanol plants. The use of CHP from cobs reduces overall GHG emissions by 60%–65% from existing dry mill ethanol plants. An integrated biorefinery further reduces corn grain ethanol GHG emissions with estimated ranges from 13.9 g CO2 equiv MJ−1 to 17.4 g CO2 equiv MJ−1. Significant radius area overlap (53% overlap for 40 km radius and 86% overlap for 80 km radius) exists for cob availability between current corn grain ethanol plants in this region suggesting possible cob supply constraints for a mature biofuel industry. A multi-feedstock approach will likely be required to meet multiple end user renewable energy requirements for the north central United States. Economic and feedstock logistics models need to account for possible supply constraints under a mature biofuel industry. - Highlights: • Corn cob biomass was estimated for the north central United States region. • Cobs were evaluated for combined heat and power generation and bioethanol. • Co-located ethanol plants showed a reduction in greenhouse gas emissions. • Biomass supply constraints may occur under a mature cellulosic ethanol scenario

  18. Genetic and epigenetic control of plant heat responses

    Directory of Open Access Journals (Sweden)

    Junzhong eLiu

    2015-04-01

    Full Text Available Plants have evolved sophisticated genetic and epigenetic regulatory systems to respond quickly to unfavorable environmental conditions such as heat, cold, drought, and pathogen infections. In particular, heat greatly affects plant growth and development, immunity and circadian rhythm, and poses a serious threat to the global food supply. According to temperatures exposing, heat can be usually classified as warm ambient temperature (about 22-27℃, high temperature (27-30℃ and extremely high temperature (37-42℃, also known as heat stress for the model plant Arabidopsis thaliana. The genetic mechanisms of plant responses to heat have been well studied, mainly focusing on elevated ambient temperature-mediated morphological acclimation and acceleration of flowering, modulation of plant immunity and circadian clock by high temperatures, and thermotolerance to heat stress. Recently, great progress has been achieved on epigenetic regulation of heat responses, including DNA methylation, histone modifications, histone variants, ATP-dependent chromatin remodeling, histone chaperones, small RNAs, long non-coding RNAs and other undefined epigenetic mechanisms. These epigenetic modifications regulate the expression of heat-responsive genes and function to prevent heat-related damage. This review focuses on recent progresses regarding the genetic and epigenetic control of heat responses in plants, and pays more attention to the role of the major epigenetic mechanisms in plant heat responses. Further research perspectives are also discussed.

  19. Heat pipe central solar receiver. Semiannual progress report, September 1, 1976--May 31, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Bienert, W. B.; Wolf, D. A.

    1977-09-01

    It is proposed to develop a solar-to-gas heat exchanger for a Central Solar Receiver Power Plant. The concept employs heat pipes to transfer the concentrated solar flux to the gaseous working medium of a Brayton cycle conversion system. During early phases of the program, an open air cycle with recuperator and a turbine inlet temperature of 800/sup 0/C was selected as the optimum design. The predicted cycle efficiency is 33 percent and the overall solar-to-electric efficiency is 20 percent. Three potential receiver configurations were also identified during the initial phases of the program. Optimum heat pipe diameter is approximately 5 cm for all three receiver configurations, and typical lengths are 2 to 3 meters. The required number of heat pipes for a 10 MWe receiver ranges from 2000 to 8000. Heat transport requirements per pipe vary from 4 to 18 Kw. Several wick structures were developed and evaluated in subscale heat pipe tests using sodium as the working fluid. One full scale heat pipe (5 cm diameter by 183 cm long) was developed and tested with sodium as the working fluid.

  20. Feasibility of a steam reforming plant heated by an HTGR

    International Nuclear Information System (INIS)

    The steam reforming of the methane using the heat from an H.T.G.R. has been studied to evaluate the feasibility of the process and the investment cost of the plant. The paper describes the main components of the plant in which each of the four intermediate heat exchangers integrated into the PCRV feeds one process train

  1. Bowmanville central switching plant for the Canadian power network

    International Nuclear Information System (INIS)

    The Darlington nuclear power station is sited about 80 km east of Toronto on the border of Lake Ontario. Commissioning is planned to be completed by 1992, and the plant will then own four units with 935 MW each, for power input to the eastwestern line of the 500 kV network of Ontario Hydro. The unit and plant auxiliary transformers of the power station are connected by 500 kV transmission lines with the Bowmanville central switching plant at a distance of 700 m. The collecting bar for the outgoing 500 kV overhead transmission lines is north of the switching plant. (orig.)

  2. Baseload Nitrate Salt Central Receiver Power Plant Design Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Tilley, Drake [Abengoa Solar LLC, Lakewood, CO (United States); Kelly, Bruce [Abengoa Solar LLC, Lakewood, CO (United States); Burkholder, Frank [Abengoa Solar LLC, Lakewood, CO (United States)

    2014-12-12

    The objectives of the work were to demonstrate that a 100 MWe central receiver plant, using nitrate salt as the receiver coolant, thermal storage medium, and heat transport fluid in the steam generator, can 1) operate, at full load, for 6,400 hours each year using only solar energy, and 2) satisfy the DOE levelized energy cost goal of $0.09/kWhe (real 2009 $). To achieve these objectives the work incorporated a large range of tasks relating to many different aspects of a molten salt tower plant. The first Phase of the project focused on developing a baseline design for a Molten Salt Tower and validating areas for improvement. Tasks included a market study, receiver design, heat exchanger design, preliminary heliostat design, solar field optimization, baseline system design including PFDs and P&IDs and detailed cost estimate. The baseline plant met the initial goal of less than $0.14/kWhe, and reinforced the need to reduce costs in several key areas to reach the overall $0.09/kWhe goal. The major improvements identified from Phase I were: 1) higher temperature salt to improve cycle efficiency and reduce storage requirements, 2) an improved receiver coating to increase the efficiency of the receiver, 3) a large receiver design to maximize storage and meet the baseload hours objective, and 4) lower cost heliostat field. The second Phase of the project looked at advancing the baseline tower with the identified improvements and included key prototypes. To validate increasing the standard solar salt temperature to 600 °C a dynamic test was conducted at Sandia. The results ultimately proved the hypothesis incorrect and showed high oxide production and corrosion rates. The results lead to further testing of systems to mitigate the oxide production to be able to increase the salt temperature for a commercial plant. Foster Wheeler worked on the receiver design in both Phase I and Phase II looking at both design and lowering costs utilizing commercial fossil boiler

  3. Central receiver power plant: an environmental, ecological, and socioeconomic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Davison, M.; Grether, D.

    1977-06-01

    The technical details of the central receiver design are reviewed. Socio-economic questions are considered including: market penetration, air industrial sector model, demands on industry, employment, effluents associated with manufacture of components, strains due to intensive construction, water requirements, and land requirements. The ecological effects in the vicinity of the central receiver plant site are dealt with, with emphasis on effects on land surface, mammals, and reptiles and amphibians. Climatological considerations are reviewed including: desert types, effects of surface albedo modification, effects of aerosols, effects on evaporation rates, the heliostat canopy, effects on turbulent transfer rates, effects on the wind profile, a model of convection about a central receiver plant, and a global scenario. Drawings of heliostat and plant design are included in appendices. (MHR)

  4. District heat for eight communities from the Beznau heat and power plant

    International Nuclear Information System (INIS)

    Almost one year after the first heat supply from the Beznau cogeneration plant of the North East Swiss Power Consortium on 15. November 1983 and the initial heat supply to the Swiss Institute for Reactor Research and the Swiss Institute for Nuclear Research, the heat supply programme of Refuna now has a totally new component: since the start of the 1984/85 heating period 100 provate consumers (small consumers and large industrial customers) in neighbouring communities are also obtaining heat from the Beznau plant. Additional premises are being linked up daily and 15 km of Refuna's new district heating network are now in service. (orig.)

  5. Zero Energy Communities with Central Solar Plants using Liquid Desiccants and Local Storage: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Burch, J.; Woods, J.; Kozubal, E.; Boranian, A.

    2012-08-01

    The zero energy community considered here consists of tens to tens-of-thousands of residences coupled to a central solar plant that produces all the community's electrical and thermal needs. A distribution network carries fluids to meet the heating and cooling loads. Large central solar systems can significantly reduce cost of energy vs. single family systems, and they enable economical seasonal heat storage. However, the thermal distribution system is costly. Conventional district heating/cooling systems use a water/glycol solution to deliver sensible energy. Piping is sized to meet the peak instantaneous load. A new district system introduced here differs in two key ways: (i) it continuously distributes a hot liquid desiccant (LD) solution to LD-based heating and cooling equipment in each home; and (ii) it uses central and local storage of both LD and heat to reduce flow rates to meet average loads. Results for piping sizes in conventional and LD thermal communities show that the LD zero energy community reduces distribution piping diameters meeting heating loads by {approx}5X and meeting cooling loads by {approx}8X for cooling, depending on climate.

  6. Heat flow and heat production in Zambia: evidence for lithospheric thinning in central Africa

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, D.S.; Pollack, H.N.

    1977-08-03

    Heat-flow results from eleven widely spaced sites in central and western regions of the Republic of Zambia range between 54 and 76 mW m/sup -2/. Ten of the sites are located in late Precambrian (Katangan) metasediments or Kibaran age basement, while one site is located in Karroo age sandstone. Compared to the global mean of 39 +- 7 (sd) mW m/sup -2/ for Precambrian provinces elsewhere, these heat-flow results are anomalously high by some 25 mW m/sup -2/. Heat-production measurements on borehole core samples indicate that enhanced radioactivity of an enriched surface zone can account for only half of the observed anomaly. The remaining anomalous heat flow must have a deeper source, and can be interpreted as a flux from the asthenosphere, providing the overlying lithosphere has been thinned to less than 60 km. Such an interpretation supports the existence of an incipient arm of the East African rift system trending southwest from Lake Tanganyika into the central African plateau.

  7. Molecular mechanisms of the plant heat stress response

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Ai-Li; Ding, Yan-Fei; Jiang, Qiong [China Jiliang University, Xueyuan Road 258, Hangzhou 310018 (China); Zhu, Cheng, E-mail: pzhch@cjlu.edu.cn [China Jiliang University, Xueyuan Road 258, Hangzhou 310018 (China)

    2013-03-08

    Highlights: ► This review elaborates the response networks of heat stress in plants. ► It elaborates proteins responding to heat stress in special physiological period. ► The proteins and pathways have formed a basic network of the heat stress response. ► Achievements of the various technologies are also combined. -- Abstract: High temperature has become a global concern, which seriously affects the growth and production of plants, particularly crops. Thus, the molecular mechanism of the heat stress response and breeding of heat-tolerant plants is necessary to protect food production and ensure crop safety. This review elaborates on the response networks of heat stress in plants, including the Hsf and Hsp response pathways, the response of ROS and the network of the hormones. In addition, the production of heat stress response elements during particular physiological periods of the plant is described. We also discuss the existing problems and future prospects concerning the molecular mechanisms of the heat stress response in plants.

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

    International Nuclear Information System (INIS)

    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. Heat recovery from a cement plant with a Marnoch Heat Engine

    International Nuclear Information System (INIS)

    This paper examines the performance of a new Marnoch Heat Engine (MHE) that recovers waste heat from within a typical cement plant. Two MHE units with compressed air as the working fluid are installed to recover the waste heat. The first unit on the main stack has four pairs of shell and tube heat exchangers. The second heat recovery unit is installed on a clinker quenching system. This unit operates with three pairs of shell and tube heat exchangers. The recovered heat is converted to electricity through the MHE system and used internally within the cement plant. A predictive model and results are presented and discussed. The results show the promising performance of the MHE's capabilities for efficient generation of electricity from waste heat sources in a cement plant. The new heat recovery system increases the efficiency of the cement plant and lowers the CO2 emissions from the clinker production process. Moreover, it reduces the amount of waste heat to the environment and lowers the temperature of the exhaust gases. - Highlights: → This paper examines the thermodynamic performance of a new Marnoch Heat Engine (MHE) that recovers waste heat to produce electricity and improve the operating efficiency of a typical cement plant. → The first unit of the MHE on the main stack has four pairs of shell and tube heat exchangers and the second heat recovery unit is installed on a clinker quenching system. → Both predicted and experimental results demonstrate the promising performance of the MHE's capabilities for efficient generation of electricity from waste heat sources in a cement plant.

  10. Nuclear reactor plant for production process heat

    International Nuclear Information System (INIS)

    The high temperature reactor is suitable as a heat source for carrying out endothermal chemical processes. A heat exchanger is required for separating the reactor coolant gases and the process medium. The heat of the reactor is transferred at a temperature lower than the process temperature to a secondary gas and is compressed to give the required temperature. The compression energy is obtained from the same reactor. (RW)

  11. Testing and plugging power plant heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Sutor, F. [Expando Seal Tools, Inc., Montgomeryville, PA (United States)

    1994-12-31

    Heat Exchanger tubes fail for any number of reasons including but certainly not limited to the cumulative effects of corrosion, erosion, thermal stress and fatigue. This presentation will attempt to identify the most common techniques for determining which tubes are leaking and then introduce the products in use to plug the leaking tubes. For the sake of time I will limit the scope of this presentation to include feedwater heaters and secondary system heat exchangers such as Hydrogen Coolers, Lube Oil Coolers, and nuclear Component Cooling Water, Emergency Cooling Water, Regenerative Heat Recovery heat exchangers.

  12. On a method for definition of optimal power of district heating nuclear power plants

    International Nuclear Information System (INIS)

    The problem is considered of the optimal power determination of district heating nuclear power plants (DHNPP) in the dependence on technical and economical indexes of the common system of central heat supply (CSCHS). The problem is solved by minimizing the efficiency function. The minimal value of year expenditures of the system in heat production is taken to be a criterion of optimality. Preliminary estimations shows the single power of DHNPP about 200 GJ/h to be economical for the majority of CSCHS in the German Democratic Republic

  13. A 2 MW heating plant supply by farmers

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, P.

    1993-12-31

    In Sweden, non-food products are encouraged since 1991, so energetic cultures develop. This paper deals with a Salix plantation and a 2 MW heating plant in Kolback supplied by salix plantations and wood waste. (TEC). 1 fig.

  14. Gas-steam turbine plant for cogenerative process at 'Toplifikacija' - Skopje (Joint-Stock Co. for district heating - Macedonia)

    International Nuclear Information System (INIS)

    The gas-steam power plant for combined heat and electric power production at A.D. 'Toplifikacija' Skopje - TO 'Zapad' is analyzed and determined. The analyzed plant is consisted of gas turbine, heat recovery steam generator (HRSG) and condensate steam turbine with controlled steam extraction. It operates on natural gas as a main fuel source. The heating of the water for the district heating is dine in the heat exchanger, with // heat of controlled extraction from condensate turbine. The advantages of the both binary plant and centralized co generative production compared with the individual are analyzed. The natural gas consumption of for both specific heating and electrical capacity in join production as well as fuel savings compared to the separate production of the same quantity of energy is also analyzed. (Original)

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

    International Nuclear Information System (INIS)

    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)

  16. Architecture of central control system for the 10 MW ECRH - plant at W7-X

    International Nuclear Information System (INIS)

    Electron Cyclotron Resonance Heating (ECRH) is the main heating method for the Wendelstein 7-X stellarator (W7-X). The mission of W7-X is to demonstrate the inherent steady state capability of stellarators at reactor relevant plasma parameters. A modular 10 MW ECRH plant at 140 GHz with 1 MW CW-capability power for each module is presently under construction at IPP-Greifswald as well as the W7-X, to meet the scientific objectives. The commissioning of the ECRH plant is well under way; three gyrotrons are operational at IPP in Greifswald. The strict modular design allows to operate each gyrotron separately and independent from all others. The ECRH plant consists not only of gyrotrons and high voltage power supplies, but also of many other devices such as superconductive magnets, collector sweep coils, gyrotron cooling systems with many water circuits and last but not least the quasi-optical transmission line for microwaves with remote controlled mirrors and further water cooled circuits. All these devices are essential for long pulse operation. A steady state ECRH has specific requirements on the stellarator machine itself, on the microwave sources, transmission elements and in particular on the central control system. The quasi steady state operation (up to 30 min) asks for real time microwave power adjustment during the different segments of one stellarator long pulse. Therefore the ECRH plant must operate with a maximum reliability and availability. A capable central control system is an important condition to achieve this goal. The central control system for the 10 MW ECRH - plant at W7-X comprises three main parts. In detail these are the voltage and current regulation of each gyrotron, the interlock system to prevent the gyrotrons from damages and the remote control system based on a hierarchy set of PLC's and computers. The architecture of this central control system is presented. (author)

  17. Firing with wood chips in heating and cogeneration plants

    International Nuclear Information System (INIS)

    The document was produced for use as detailed teaching material aimed at spreading information on the use of wood chips as fuel for heating and cogeneration plants. It includes information and articles on wood fuels generally, combustion values, chopping machines, suppliers, occupational health hazards connected with the handling of wood chips, measuring amounts, the selection of types, prices, ash, environmental aspects and information on the establishment of a wood-chip fired district heating plant. (AB)

  18. Exploitation of the waste-heat from hydro power plants

    International Nuclear Information System (INIS)

    This paper presents the possibility of exploiting low-temperature heat from the generators' cooling system within a hydro power plant, using a HTHP (high temperature heat-pump) that enables heating at up to 85 °C. The results based on theoretical calculations are presented for heat-flows, the powers of the compressors, and COP (coefficient of performance) values for the cases when using the refrigerant R717 and a single stage high pressure compressor (up to 50 bar) under varying operational conditions. Real possibilities are presented for heat production based on measurements of a closed cooling system of generators, thus showing that the total efficiencies of generators can be enhanced by up to 1% whilst reducing the electricity consumption during the electric heating of buildings. In addition, the simulations of cost and revenue, and cumulatively discounted cash-flows of the investment in HTHP are presented using the MS Excel computer program. The payback period for the investment in a 500 kW high-temperature heat-pump for exploiting low-temperature heat of the generators' cooling system would be approximately 2 years for the case of heating the commercial buildings of the hydro power plant, and 7 years for the case when heating the fluid within the nearby district heating systems of urban settlements. - Highlights: • Article describes the use of generators' heat within a hydroelectric power plant. • Total energy efficiency of hydroelectric generators can thus be increased by up to 1%. • High-temperature heat-pump allows a temperature rise of up to 85 °C with COP (coefficient of performance) > 5. • Heat recovery of a generator cooling system is very economical

  19. Solar central receiver reformer system for ammonia plants

    Science.gov (United States)

    1980-07-01

    An overview of a study to retrofit the Valley Nitrogen Producers, Inc., El Centro, California 600 ST/SD Ammonia Plant with Solar Central Receiver Technology is presented. The retrofit system consists of a solar central receiver reformer (SCRR) operating in parallel with the existing fossil fired reformer. Steam and hydrocarbon react in the catalyst filled tubes of the inner cavity receiver to form a hydrogen rich mixture which is the syngas feed for the ammonia production. The SCRR system will displace natural gas presently used in the fossil reformer combustion chamber.

  20. Water recovery using waste heat from coal fired power plants.

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Stephen W.; Morrow, Charles W.; Altman, Susan Jeanne; Dwyer, Brian P.

    2011-01-01

    The potential to treat non-traditional water sources using power plant waste heat in conjunction with membrane distillation is assessed. Researchers and power plant designers continue to search for ways to use that waste heat from Rankine cycle power plants to recover water thereby reducing water net water consumption. Unfortunately, waste heat from a power plant is of poor quality. Membrane distillation (MD) systems may be a technology that can use the low temperature waste heat (<100 F) to treat water. By their nature, they operate at low temperature and usually low pressure. This study investigates the use of MD to recover water from typical power plants. It looks at recovery from three heat producing locations (boiler blow down, steam diverted from bleed streams, and the cooling water system) within a power plant, providing process sketches, heat and material balances and equipment sizing for recovery schemes using MD for each of these locations. It also provides insight into life cycle cost tradeoffs between power production and incremental capital costs.

  1. Numerical Modelling of Induction Heating Process for Testing Plant

    OpenAIRE

    HRENIUC Ruslan Ovidiu; TIURBE Cristian

    2012-01-01

    This paper presents the numerical modelling of electromagnetic and thermal fields in the induction heating of a 2 kW testing plant, made by the author. The purpose of this modelling is to analyze thedevelopment of heating process, to notice any changes required to increase its efficiency. Modelling is performed by means of FLUX software package.

  2. Utilization of Low Temperature Heat in Coal based Power Plants

    OpenAIRE

    Sisic, Elmir

    2013-01-01

    Carbon Capture and Storage aims at capturing and storing carbon emissions from large point sources underground. One of three main ways of implementing CCS is in coal based power plants is the pressurized oxy-combustion, an advanced form of oxy-combustion. There are different approaches in designing the heat cycle with CCS. Included in the design is the acid condenser, a heat exchanger which utilizes the low temperature and latent heat of the flue gas for preheating purposes. The objective of ...

  3. Investigation of bubble behaviours in wet central heating systems

    Directory of Open Access Journals (Sweden)

    Shefik Ali

    2014-03-01

    Full Text Available A series of experimental measurements has been conducted in order to investigate the bubble behaviours through the horizontal pipe line of the domestic wet central heating systems. Obtained results exposed the effect of 90 degree bend, buoyancy forces on bubbly two phase flow patterns and effect of velocity on void fractions and bubble diameters. Distance chosen for the first sight glass (HSG0 was sufficient enough to note the effect of 90 degree bend on void fraction patterns. Due to the effect of 90 degree bend, position of the peak void fractions across the pipe section lowers, with an increase in bulk fluid velocity. Bubbles tend to flow for longer distance at the bottom of the pipe section. Buoyancy force effect is demonstrated with figures for highest bulk fluid velocity at three different positions. Analysis of four different flow rates at two different saturation ratios show reduction for average bubble diameters and void fractions when bulk fluid velocity increases. An attempt to predict bubble dissolution rates across the horizontal pipeline of the system is made, however results show some uncertainties.

  4. FACTORS AFFECTING HEAT TOLERANCE IN CROSSBRED CATTLE IN CENTRAL BRAZIL

    Directory of Open Access Journals (Sweden)

    Concepta Margaret McManus

    2014-06-01

    Full Text Available This study compared the adaptation traits in common crosses of crossbred dairy cattle in central Brazil. Twenty animals of each of three genetic groups were used: zebu (Bos indicus, Simmental x Zebu (SZ and Holstein x Zebu (HZ. The test measured variations in rectal temperature (RT, respiration rate (RR and heart rate (HR of animals in the shade and after exposure to the sun, as well as mean daily milk production throughout the lactation period. The procedure was repeated three times. There were significant interactions between test group and genetic group for the traits investigated and the correlations among traits were low. The RR of the crossbred groups may be controlling body temperature in such a way as not to cause an increase in RT. Milk production influenced RR in crossbred cows exposed to the sun, confirming their poorer adaptation in comparison with zebu cows. We observed that the adaptation can be measured in terms of production within the same genetic group. In conclusion, the crosses with European breeds produced more milk than zebu, although they were influenced by heat/solar radiation.

  5. Computations of flow and heat transfer in power plant condensers

    International Nuclear Information System (INIS)

    A computational procedure has been developed to model the two-dimensional flow and heat transfer in power plant condensers. This paper presents an outline of the procedure together with its application to model condensation in simple laboratory rigs and in a more complex power plant configuration

  6. 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)

  7. Desalination demonstration plant using nuclear heat

    International Nuclear Information System (INIS)

    Most of the desalination plants which are operating throughout the world utilize the energy from thermal power station which has the main disadvantage of polluting the environment due to combustion of fossil fuel and with the inevitable rise in prices of fossil fuel, nuclear driven desalination plants will become more economical. So it is proposed to set up nuclear desalination demonstration plant at the location of Madras Atomic Power Station (MAPS), Kalpakkam. The desalination plant will be of a capacity 6300 m3/day and based on both Multi Stage Flash (MSF) and Sea Water Reverse Osmosis (SWRO) processes. The MSF plant with performance ratio of 9 will produce water total dissolved solids (TDS-25 ppm) at a rate of 4500 m3/day from seawater of 35000 ppm. A part of this water namely 1000 m3/day will be used as Demineralised (DM) water after passing it through a mixed bed polishing unit. The remaining 3500 m3/day water will be mixed with 1800 m3/day water produced from the SWRO plant of TDS of 400 ppm and the same be supplied to industrial/municipal use. The sea water required for MSF and SWRO plants will be drawn from the intake/outfall system of MAPS which will also supply the required electric power pumping. There will be net 4 MW loss of power of MAPS namely 3 MW for MSF and 1 MW for SWRO desalination plants. The salient features of the project as well as the technical details of the both MSF and SWRO processes and its present status are given in this paper. It also contains comparative cost parameters of water produced by both processes. (author)

  8. Comparative ecobalancing accounting of semi-central house heat supply from wood residues; Vergleichende Oekobilanzierung der semi-zentralen Hauswaermebereitstellung aus Holzreststoffen

    Energy Technology Data Exchange (ETDEWEB)

    Biemann, Kirsten

    2015-07-01

    In 2008 almost 40 percent of the German final energy demand was used for room heating and hot water supply. To decrease environmental burdens and to save fossil resources a restructuring of the heating sector is needed. Therefore legislation enforces higher insulation standards of buildings and a more frequent use of renewable energies as well as heating networks. Wood as a renewable and storable energy source is an attractive fuel. However, it must be used as efficiently as possible because of limited wood supplies. Connecting buildings via a heating network is a good option since bigger heating plants can operate at higher efficiencies than small heaters. However, the higher insulation standards of the buildings often oppose the construction of a heating network, because heating networks work best with high energy demands and low network lengths. Therefore the environmental and economic feasibility of new heating networks needs to be checked beforehand. This thesis explores the environmental burdens of different semi- centralized heating networks using wood residues as fuel. A semi- centralized heating network is a network with no more than 500 customers and a heating plant with less than 5 MWth. While wood residues are used in the base load plant, peak load is covered by a gas heating plant. As a method to analyze the potential environmental burdens of the heat supply a life cycle assessment according to ISO 14040/44 is used. Opposed to former life cycle assessment studies, construction and operation of the network is included in the assessment. Even though the environmental impacts of the semi- centralized heating from wood residues are dominated by the heat supply, an observation of the impacts solely at the heating plant is not sufficient. By varying the boundary conditions of the heating network two main contributors to the environmental impacts are found. In addition to the heat production at the plant the type of the buildings in the settlement has a huge

  9. 77 FR 8178 - Test Procedures for Central Air Conditioners and Heat Pumps: Public Meeting

    Science.gov (United States)

    2012-02-14

    ... distribution of those central air conditioning systems and heat pump systems manufactured after January 1, 2010, that are designed to use R-22 refrigerant. 74 FR 66450 (Dec. 15, 2009). EPA's rulemaking included an... issued two guidance documents surrounding testing central air conditioner and heat pump systems...

  10. Indirect heat integration across plants using hot water circles☆

    Institute of Scientific and Technical Information of China (English)

    Chenglin Chang; Yufei Wang; Xiao Feng

    2015-01-01

    Total site heat integration (TSHI) provides more opportunities for energy saving in industry clusters. Some design methods including direct integration using process streams and indirect integration using intermediate-fluid cir-cuits, i.e., steam, dowtherms and hot water, have been proposed during last few decades. Indirect heat integration is preferred when the heat sources and sinks are separated in independent plants with rather long distance. This improves energy efficiency by adaption of intermediate fluid circle which acts as a utility provider for plants in a symbiotic network. However, there are some significant factors ignored in conventional TSHI, i.e. the investment of pipeline, cost of pumping and heat loss. These factors simultaneously determine the possibility and perfor-mance of heat integration. This work presents a new methodology for indirect heat integration in low tempera-ture range using hot water circuit as intermediate-fluid medium. The new methodology enables the targeting of indirect heat integration across plants considering the factors mentioned earlier. An MINLP model with economic objective is established and solved. The optimization results give the mass flow rate of intermediate-fluid, diam-eter of pipeline, the temperature of the circuits and the matches of heat exchanger networks (HENS) automati-cally. Finally, the application of this proposed methodology is il ustrated with a case study.

  11. Nuclear power plant waste heat utilization

    International Nuclear Information System (INIS)

    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 +- 20F; 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 600F. 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

    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.

  13. Performance Evaluation of Heat Exchangers in a Polyethylene Plant

    Directory of Open Access Journals (Sweden)

    Barinaadaa Thaddeus Lebele-Alawa

    2013-01-01

    Full Text Available This paper evaluates the performance of three heat exchanger units (2-E-2301, 3-E-901 and 3-E-401 in a polyethylene plant. Steady state monitoring and direct collection of data from the equipment in the plant were performed and the data were analyzed by using energy equations to determine the overall heat transfer coefficient, heat duty, temperature and pressure range of hot and cold fluids, capacity ratio and effectiveness. The results show that for 2-E-2301, the overall heat transfer coefficient is over 50 percent less than the design figure and the heat duty is over 75 percent than the design figure. For the 3-E-901 the heat duty and the overall heat transfer are over 75 percent less than the design figure which was traceable to fouling. This affected the effectiveness, capacity ratio and temperature range of the hot and cold fluid. For the 3-E-401, the heat duty was found to be within the limit of design figure. The temperature difference in the hot fluid side and the capacity ratio were within the limits of the design figure. Thus, the results show qualitative performance evaluation of the heat exchangers.

  14. Regional district heating network Refuna: Heat extraction in nuclear power plant Beznau extended

    International Nuclear Information System (INIS)

    The positive effects of the heat extraction from the nuclear power plant Beznau, in particular its contribution to the protection of the environment by substituting fossile fuels, have been established. The individual's contribution, which is practically demonstrated by the connection to district heating, is not only of moral significance, but has also concrete and practical effects. The example of heat extraction in Beznau shall mobilize us to enter further engagements for the protection of the environment. (orig.)

  15. Sustainability Assessment of a Self-Consumption Wood-Energy Chain on Small Scale for Heat Generation in Central Italy

    OpenAIRE

    Stefano Verani; Giulio Sperandio; Rodolfo Picchio; Enrico Marchi; Corrado Costa

    2015-01-01

    The sustainability of a small-scale self-consumption wood-energy chain for heat generation in central Italy was analyzed from a technical, economic and energetic point of view. A micro-chain was developed within the CRA-ING farm at Monterotondo (Rome, Italy): The purpose of this system was to produce biomass for supplying a heating plant within the CRA-ING property as a substitute for diesel fuel. A poplar short rotation coppice, established with clones AF2, AF6 and Monviso, fed the micro-cha...

  16. Climate change, workplace heat exposure, and occupational health and productivity in Central America.

    Science.gov (United States)

    Kjellstrom, Tord; Crowe, Jennifer

    2011-01-01

    Climate change is increasing heat exposure in places such as Central America, a tropical region with generally hot/humid conditions. Working people are at particular risk of heat stress because of the intrabody heat production caused by physical labor. This article aims to describe the risks of occupational heat exposure on health and productivity in Central America, and to make tentative estimates of the impact of ongoing climate change on these risks. A review of relevant literature and estimation of the heat exposure variable wet bulb globe temperature (WBGT) in different locations within the region were used to estimate the effects. We found that heat stress at work is a real threat. Literature from Central America and heat exposure estimates show that some workers are already at risk under current conditions. These conditions will likely worsen with climate change, demonstrating the need to create solutions that will protect worker health and productivity. PMID:21905396

  17. ALGORITHM FOR OPTIMIZATION OF STRUCTURE AND COMPOSITION OF CENTRALIZED HEAT-SUPPLY SYSTEM

    OpenAIRE

    V. Sednin; Korznikov, A.; A. Sednin; I. Shkliar

    2014-01-01

     The paper presents algorithms for structure optimization of centralized heat-supply systems in large cities due to higher heat loads and necessity for equipment change. The algorithms can be applied for elaboration of plans for development of heat supply in cities and human settlements.

  18. ALGORITHM FOR OPTIMIZATION OF STRUCTURE AND COMPOSITION OF CENTRALIZED HEAT-SUPPLY SYSTEM

    Directory of Open Access Journals (Sweden)

    V. Sednin

    2014-09-01

    Full Text Available  The paper presents algorithms for structure optimization of centralized heat-supply systems in large cities due to higher heat loads and necessity for equipment change. The algorithms can be applied for elaboration of plans for development of heat supply in cities and human settlements.

  19. Analysis of the Impact of Decreasing District Heating Supply Temperature on Combined Heat and Power Plant Operation

    Directory of Open Access Journals (Sweden)

    Bolonina Alona

    2014-12-01

    Full Text Available District heating systems are widely used to supply heat to different groups of heat consumers. The district heating system offers great opportunities for combined heat and power production. In this paper decreasing district heating supply temperature is analysed in the context of combined heat and power plant operation. A mathematical model of a CHP plant is developed using both empirical and theoretical equations. The model is used for analysis of modified CHP plant operation modes with reduced district heating supply temperature. Conclusions on the benefits of new operation modes are introduced.

  20. Analysis of the Impact of Decreasing District Heating Supply Temperature on Combined Heat and Power Plant Operation

    Science.gov (United States)

    Bolonina, Alona; Bolonins, Genadijs; Blumberga, Dagnija

    2014-12-01

    District heating systems are widely used to supply heat to different groups of heat consumers. The district heating system offers great opportunities for combined heat and power production. In this paper decreasing district heating supply temperature is analysed in the context of combined heat and power plant operation. A mathematical model of a CHP plant is developed using both empirical and theoretical equations. The model is used for analysis of modified CHP plant operation modes with reduced district heating supply temperature. Conclusions on the benefits of new operation modes are introduced.

  1. Dynamic disturbance rejection controllers for neutral time delay systems with application to a central heating system

    Institute of Scientific and Technical Information of China (English)

    KOUMBOULIS Fotis N.; KOUVAKAS Nikolaos D.; PARASKEVOPOULOS Paraskevas N.

    2009-01-01

    In the present paper the problem of disturbance rejection of single input-single output neutral time delay systems with multiple measurable disturbances is solved via dynamic controllers. In particular, the general form of the controller matrices is presented, while the necessary and sufficient conditions for the controller to be realizable are offered. The proposed technique is applied to a test case neutral time delay central heating system. In particular, the nonlinear model of the plant and its linearized approximation are presented. Based on the linearized model, a two-stage controller is designed in order to regulate the room temperature and the boiler effluent temperature. The performance of the closed loop system is investigated through computational experiments.

  2. Heat extraction in nuclear power plant Beznau (Switzerland)

    International Nuclear Information System (INIS)

    The district heat extraction system installed and commissioned at the Beznau Nuclear Power Plant (Canton Argovia) less than seven years ago has been a success from the very beginning. Over a 28 kilometres long main network and with to date 65 kilometres of distribution pipelines the eight founding communities as well as three newly joined networks have been connected after an extremely short construction time. Around 1600 consumers of the 'REFUNA' district heating network, small and large private houses, business and industrial complexes today are supplied with heat from the Beznau plant. The regional district heat supply system has thus become a fix part of the regional infrastructure for around 18'000 inhabitants of the lower Aare valley. (author) 12 figs., 8 refs

  3. Energy Saving Opportunities in Heat Integrated Beverage Plant Retrofit

    OpenAIRE

    Tokos, Hella; Pintarič, Zorka Novak; Glavič, Peter

    2009-01-01

    Abstract This paper presents practical applications of mathematical programming for energy integration in a large beverage plant. The opportunities of heat integration between batch operations were analysed by a Mixed Integer Linear Programming (MILP) model, which was slightly modified by considering specific industrial circumstances. The feasibility of combined electricity, heating and cooling production was studied using a simplified MILP model, developed for the selection of an ...

  4. Use of waste heat from nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Use of waste heat from nuclear power plants

    International Nuclear Information System (INIS)

    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

  6. Transient analysis of a molten salt central receiver (MSCR) in a solar power plant

    Science.gov (United States)

    Joshi, A.; Wang, C.; Akinjiola, O.; Lou, X.; Neuschaefer, C.; Quinn, J.

    2016-05-01

    Alstom is developing solar power tower plants utilizing molten salt as the working fluid. In solar power tower, the molten salt central receiver (MSCR) atop of the tower is constructed of banks of tubes arranged in panels creating a heat transfer surface exposed to the solar irradiation from the heliostat field. The molten salt heat transfer fluid (HTF), in this case 60/40%wt NaNO3-KNO3, flows in serpentine flow through the surface collecting sensible heat thus raising the HTF temperature from 290°C to 565°C. The hot molten salt is stored and dispatched to produce superheated steam in a steam generator, which in turn produces electricity in the steam turbine generator. The MSCR based power plant with a thermal energy storage system (TESS) is a fully dispatchable renewable power plant with a number of opportunities for operational and economic optimization. This paper presents operation and controls challenges to the MSCR and the overall power plant, and the use of dynamic model computer simulation based transient analyses applied to molten salt based solar thermal power plant. This study presents the evaluation of the current MSCR design, using a dynamic model, with emphasis on severe events affecting critical process response, such as MS temperature deviations, and recommend MSCR control design improvements based on the results. Cloud events are the scope of the transient analysis presented in this paper. The paper presents results from a comparative study to examine impacts or effects on key process variables related to controls and operation of the MSCR plant.

  7. District heating plants in Europe: Recent experience and innovations

    International Nuclear Information System (INIS)

    This paper contains a critical review of recent experience and innovative features encountered in some European district heating plants. The increased application of cogeneration is pointed out, with reference to traditional, as well as, more recent technology which makes use of combined gas-steam cycles. An example of a combined gas-steam cycle is schematically described. The relevance of fluidized bed combustion and interconnection of heat distribution grids, and their consequences to the environmentally-safe and economical employment of the plants, are evidenced

  8. U. S. Central Station Nuclear Power Plants: operating history

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-01

    The information assembled in this booklet highlights the operating history of U. S. Central Station nuclear power plants through December 31, 1976. The information presented is based on data furnished by the operating electric utilities. The information is presented in the form of statistical tables and computer printouts of major shutdown periods for each nuclear unit. The capacity factor data for each unit is presented both on the basis of its net design electrical rating and its net maximum dependable capacity, as reported by the operating utility to the Nuclear Regulatory Commission.

  9. U.S. Central Station Nuclear Power Plants: operating history

    International Nuclear Information System (INIS)

    The information assembled in this booklet highlights the operating history of U. S. Central Station nuclear power plants through December 31, 1976. The information presented is based on data furnished by the operating electric utilities. The information is presented in the form of statistical tables and computer printouts of major shutdown periods for each nuclear unit. The capacity factor data for each unit is presented both on the basis of its net design electrical rating and its net maximum dependable capacity, as reported by the operating utility to the Nuclear Regulatory Commission

  10. 75 MW heat extraction from Beznau nuclear power plant (Switzerland)

    International Nuclear Information System (INIS)

    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)

  11. Waste heat recovery in a coffee roasting plant

    Energy Technology Data Exchange (ETDEWEB)

    Monte, M. De; Padoano, E.; Pozzetto, D. [Via A Valerio, Trieste (Italy). Dept. of Energetics

    2003-06-01

    The paper presents the possibility of introducing, in the event of substitution of an old plant, the recovery of heat produced during the roasting process of coffee. During the analysis, thermo and fluid dynamic operating parameters of the present plant were defined also with the support of an experimental measuring campaign. Energy recovery possibilities were then evaluated, and a possible plant solution was examined taking into consideration its economic feasibility. The case study is also interesting because the methodology used for the analysis can be generally applied to production plants, which have hot air exhaust emissions. Waste heat recovery is an important topic, not only for its economic benefits, but also for its environmental outcomes and resource saving. (author)

  12. Dimensionally similar discharges with central rf heating on the DIII-D tokamak

    International Nuclear Information System (INIS)

    The scaling of L-mode heat transport with normalized gyroradius is investigated on the DIII-D tokamak using central rf heating. A toroidal field scan of dimensionally similar discharges with central ECH and/or fast wave heating show gyro-Bohm-like scaling both globally and locally. The main difference between these restats and those using NBI heating on DIII-D is that with rf heating the deposition profile is not very sensitive to the plasma density. Therefore central heating can be utilized for both the low-B and high-B discharges, whereas for NBI the power deposition is decidedly off-axis for the high-B discharge (i.e., high density)

  13. Economics of long distance transmission, storage and distribution of heat from nuclear plants with existing and newer techniques

    International Nuclear Information System (INIS)

    Nuclear plants can provide heat for district heating in mainly two ways. Central nuclear power plants sufficiently large to be economic as electricity producers could instead be designed for heat extraction at temperatures useful for district heating. The second promising way is to design simple low temperature reactors, so simple and safe that near urban location becomes feasible. The manner of transport distribution and storage of heat is discussed in this paper which are very important especially in the cost calculations. The economic objectives can often be attained already with conventional technigues even when transport distances are large. But newer techniques of transport promise to make even cities at greater distances from major nuclear power plants economically connectible whilst new techniques for small distribution pipes help to extend the economic distribution area to the less dense one-family house districts. (M.S.)

  14. Dissipation of the reactor heat at the Savannah River Plant

    International Nuclear Information System (INIS)

    The effluent cooling water from the heat exchangers of the Savannah River nuclear reactors is cooled by natural processes as it flows through the stream beds, canals, ponds, and swamps on the plant site. The Langhaar equation, which gives the rate of heat removal from the water surface as a function of the surface temperature, air temperature, relative humidity, and wind speed, is applied satisfactorily to calculate the cooling that occurs at all temperature levels and for all modes of water flow. The application of this equation requires an accounting of effects such as solar heating, shading, mixing, staging, stratification, underflow, rainfall, the imposed heat load, and the rate of change in heat content of the body of water

  15. Waste heat problems in connection with power plants

    International Nuclear Information System (INIS)

    The erection of additional thermal power plants on a fossil as well as nuclear basis increasingly raises problems caused by waste heat, which are discussed in more detail. Besides the physical fundamentals of the various cooling systems, the paper specifies the costs involved in alternative cooling methods. Model approaches for dispersion, mixing and heat losses in connection with cooling tower waste air plumes indicate possible solutions with a view to the entire complex of cooling tower/environment for describing environmental effects, giving particular consideration to the field of gas radiation. Model calculations provide examples for potential small-space influence on the climate in the vicinity of cooling towers. The problem of large-space weather changes is equally dealt with. Finally, the direct application of cooling water in agricultural areas, the use of heat pumps for raising the waste heat temperature level, and the possibility of coupling heat production with power production are examined in more detail. (orig.)

  16. Piping information centralized management system for nuclear plant, PIMAS

    International Nuclear Information System (INIS)

    Piping works frequently cause many troubles in the progress of construction works, because piping is the final procedure in design and construction and is forced to suffer the problems in earlier stages. The enormous amount of data on quality control and management leads to the employment of many unskilled designers of low technical ability, and it causes confusion in installation and inspection works. In order to improve the situation, the ''piping information management system for nuclear plants (PIMAS)'' has been introduced attempting labor-saving and speed-up. Its main purposes are the mechanization of drafting works, the centralization of piping informations, labor-saving and speed-up in preparing production control data and material management. The features of the system are as follows: anyone can use the same informations whenever he requires them because the informations handled in design works are contained in a large computer; the system can be operated on-line, and the terminals are provided in the sections which require informations; and the sub-systems are completed for preparing a variety of drawings and data. Through the system, material control has become possible by using the material data in each plant, stock material data and the information on the revision of drawings in the design department. Efficiency improvement and information centralization in the manufacturing department have also been achieved because the computer has prepared many kinds of slips based on unified drawings and accurate informations. (Wakatsuki, Y.)

  17. Bioindicator plants for ambient ozone in Central and Eastern Europe

    International Nuclear Information System (INIS)

    Sixteen species of native detector plants for ambient ozone have been identified for use in Central and Eastern Europe. They include the forbs Alchemilla sp., Astrantia major, Centuarea nigra, Centauria scabiosa, Impatiens parviflora, Lapsana communis, Rumex acetosa and Senecio subalpinus; the shrubs Corylus avellana, Cornus sanguinea and Sambucus racemosa; the trees Alnus incana, Pinus cembra and Sorbus aucuparia; and the vines Humulus lupulus and Parthenocissus quinquefolia. Sensitivity to ozone and symptoms have been verified under controlled exposure conditions. Under these conditions, symptom incidence, intensity and appearance often changed with time after removal from exposure chambers. Ozone sensitivity for four species: Astrantia major, Centuarea nigra, C. scabiosa and Humulus lupulus are reported here for the first time. The other 12 species have also been confirmed by others in Western Europe. It is recommended that these detector bioindicator species be used in conjunction with ozone monitors and passive samplers so that injury symptoms incidence can be used to give biological significance to monitored ambient ozone data. - Sixteen species of verified bioindicator plants for ambient ozone are available for use in Central and Eastern Europe

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

    International Nuclear Information System (INIS)

    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

  19. 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.

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

    International Nuclear Information System (INIS)

    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)

  1. EFFICIENCY AND LIFETIME OF SOLAR COLLECTORS FOR SOLAR HEATING PLANTS

    DEFF Research Database (Denmark)

    The 12.5 m² flat plate solar collector HT, today marketed by Arcon Solvarme A/S, has been used in solar heating plants in Scandinavia since 1983. The collector is designed to operate in a temperature interval between 40°C and 90°C. The efficiency of the collector has been strongly improved since...... it was introduced on the market. The paper will present the increase of the efficiency of the collector due to technical improvements since 1983. Further, measurements from the spring of 2009 of the efficiency of two HT collectors, which have been in operation in the solar heating plant Ottrupgaard, Skørping......, Denmark since 1994 with a constant high flow rate and in the solar heating plant Marstal, Denmark since 1996 with a variable flow rate, will be presented. The efficiencies will be compared to the efficiencies of the collectors when they were first installed in the solar heating plants. The measurements...

  2. EFFICIENCY AND LIFETIME OF SOLAR COLLECTORS FOR SOLAR HEATING PLANTS

    DEFF Research Database (Denmark)

    Fan, Jianhua; Chen, Ziqian; Furbo, Simon;

    2009-01-01

    The 12.5 m² flat plate solar collector HT, today marketed by Arcon Solvarme A/S, has been used in solar heating plants in Scandinavia since 1983. The collector is designed to operate in a temperature interval between 40°C and 90°C. The efficiency of the collector has been strongly improved since...... it was introduced on the market. The paper will present the increase of the efficiency of the collector due to technical improvements since 1983. Further, measurements from the spring of 2009 of the efficiency of two HT collectors, which have been in operation in the solar heating plant Ottrupgaard, Skørping......, Denmark since 1994 with a constant high flow rate and in the solar heating plant Marstal, Denmark since 1996 with a variable flow rate, will be presented. The efficiencies will be compared to the efficiencies of the collectors when they were first installed in the solar heating plants. The measurements...

  3. 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 are....... The scenarios are assessed on their total socioeconomic costs and the biomass consumption. The CCGT CHP plant is concluded to be the most feasible of the assessed types considering both a technical analysis and a market economic analysis with electricity exchange. It is also concluded that the current...

  4. Shrines in Central Italy conserve plant diversity and large trees.

    Science.gov (United States)

    Frascaroli, Fabrizio; Bhagwat, Shonil; Guarino, Riccardo; Chiarucci, Alessandro; Schmid, Bernhard

    2016-05-01

    Sacred natural sites (SNS) are instances of biocultural landscapes protected for spiritual motives. These sites frequently host important biological values in areas of Asia and Africa, where traditional resource management is still upheld by local communities. In contrast, the biodiversity value of SNS has hardly been quantitatively tested in Western contexts, where customs and traditions have relatively lost importance due to modernization and secularization. To assess whether SNS in Western contexts retain value for biodiversity, we studied plant species composition at 30 SNS in Central Italy and compared them with a paired set of similar but not sacred reference sites. We demonstrate that SNS are important for conserving stands of large trees and habitat heterogeneity across different land-cover types. Further, SNS harbor higher plant species richness and a more valuable plant species pool, and significantly contribute to diversity at the landscape scale. We suggest that these patterns are related not only to pre-existent features, but also to traditional management. Conservation of SNS should take into account these specificities, and their cultural as well as biological values, by supporting the continuation of traditional management practices. PMID:26701326

  5. Combined heat-and-power plants and district heating in a deregulated electricity market

    International Nuclear Information System (INIS)

    In this paper, a municipality with district heating supplied via boilers and combined heat-and-power (CHP) plants is studied. The electricity load in the municipality is provided for by the CHP plant and electricity bought from the Nordic electricity market. It is therefore desirable to produce as much electricity as possible during periods when the price of electricity is high. The variations in the price of electricity over a 24-h period are significant. The idea presented in this paper is that heat storage can be used to maximise the amount of electricity produced in the CHP plants during peak-price periods. It can also be used to minimise the use of plants with higher operational costs. For storing heat, both a hot-water accumulator at the CHP plant and storage in the building stock are suggested. The situation is analysed using a mixed integer linear-programming model and a case study is presented for the city of Linkoping, a City of approximately 130,000 inhabitants, situated 200 km south of Stockholm in Sweden. A simple model for forecasting the electricity price on the Nordic electricity market is also presented. (Author)

  6. Balance-of-plant heat exchanger condition assessment guidelines

    International Nuclear Information System (INIS)

    In nuclear power plants, service water system heat exchanger integrity and thermal performance are receiving close scrutiny to ensure that they perform their functions in an emergency condition. Many safety-related service water systems are called upon to function only in emergency conditions and are therefore difficult to monitor on a regular basis to ensure functionality. For some heat exchangers it is difficult to measure and extrapolate their thermal performance data since performance testing is often conducted at flows, temperatures, and heat loads which are different from design conditions. Tube fouling and plugged tubes may also contribute to this difficulty. Performance testing and analysis of heat exchanger alone does not provide information relative to structural integrity of remaining tubes. This document is provided to complement the existing performance testing with a periodic inservice inspection program

  7. THE PROPERTIES OF HOUSES IN TERMS OF GEOTHERMAL CENTRAL HEATING AND THE APPROACH OF DENIZLI TO GEOTHERMAL ENERGY

    Directory of Open Access Journals (Sweden)

    Halil KARAHAN

    1996-01-01

    Full Text Available Although the geothermal fluid, which is discharged into Büyük Menderes River after electric generation at Kızıldere Geothermal power plant, has been considered as a solution the air pollution problem of Denizli province, there has been no work carried out to determine the number of house, the area of house, the type of heating, coal consumption for each house, heat isolation, and centrally heated houses. The existing works includes only the applications at local places comparing to Denizli. In order to get maximum benefit from the planned project, it is necessary to collect data for Denizli and evaluate the data at the feasibility and application phases of the project. For this purpose questionnaire forms have been given to 15000 houses and offices at the different places in Denizli. The questionnaire forms were collected and the results have been evaluated and presented in graphics.

  8. Chloroplast Retrograde Regulation of Heat Stress Responses in Plants.

    Science.gov (United States)

    Sun, Ai-Zhen; Guo, Fang-Qing

    2016-01-01

    It is well known that intracellular signaling from chloroplast to nucleus plays a vital role in stress responses to survive environmental perturbations. The chloroplasts were proposed as sensors to heat stress since components of the photosynthetic apparatus housed in the chloroplast are the major targets of thermal damage in plants. Thus, communicating subcellular perturbations to the nucleus is critical during exposure to extreme environmental conditions such as heat stress. By coordinating expression of stress specific nuclear genes essential for adaptive responses to hostile environment, plants optimize different cell functions and activate acclimation responses through retrograde signaling pathways. The efficient communication between plastids and the nucleus is highly required for such diverse metabolic and biosynthetic functions during adaptation processes to environmental stresses. In recent years, several putative retrograde signals released from plastids that regulate nuclear genes have been identified and signaling pathways have been proposed. In this review, we provide an update on retrograde signals derived from tetrapyrroles, carotenoids, reactive oxygen species (ROS) and organellar gene expression (OGE) in the context of heat stress responses and address their roles in retrograde regulation of heat-responsive gene expression, systemic acquired acclimation, and cellular coordination in plants. PMID:27066042

  9. Sustainability Assessment of a Self-Consumption Wood-Energy Chain on Small Scale for Heat Generation in Central Italy

    Directory of Open Access Journals (Sweden)

    Stefano Verani

    2015-06-01

    Full Text Available The sustainability of a small-scale self-consumption wood-energy chain for heat generation in central Italy was analyzed from a technical, economic and energetic point of view. A micro-chain was developed within the CRA-ING farm at Monterotondo (Rome, Italy: The purpose of this system was to produce biomass for supplying a heating plant within the CRA-ING property as a substitute for diesel fuel. A poplar short rotation coppice, established with clones AF2, AF6 and Monviso, fed the micro-chain. The rotation was biennial. The average plantation production (Mgd.m.·ha−1·year−1 was 10.2, with a maximum of 13.53 for the twin-rows AF2 and a minimum of 8.00 for the single-row Monviso. The economic assessment was based on the Net Present Value (NPV method and the equivalent annuity cost, and found an average saving of 15.60 €·GJ−1 of heat generated by the wood chips heating system in comparison with the diesel heating system over a 10 year lifetime of the thermal power plant. The energy assessment of the poplar plantation, carried out using the Gross Energy Requirements method, reported an energy output/input ratio of 12.3. The energy output/input ratio of the whole micro-chain was 4.5.

  10. Large combined heat and power plants in sustainable energy systems

    DEFF Research Database (Denmark)

    Lund, Rasmus Søgaard; Mathiesen, Brian Vad

    2015-01-01

    In many countries, the electricity supply and power plant operation are challenged by increasing amounts of fluctuating renewable energy sources. A smart energy system should be developed to integrate as much energy supply from fluctuating renewable sources and to utilise the scarce biomass...... resources as efficiently as possible. Using the advanced energy systems analysis tool EnergyPLAN and Denmark as a case, this analysis defines which of the three assessed types of CHP plants connected to district heating systems is most feasible in terms of total socioeconomic costs and biomass consumption....... It is concluded that the CCGT CHP plant is the most feasible both from a technical analysis and a market economic analysis with electricity exchange. It is found that the current economic framework for large CHP plants in Denmark generates a mismatch between socio economy and business economy as well...

  11. Advective heat transport associated with regional Earth degassing in central Apennine (Italy)

    OpenAIRE

    Chiodini, G.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Cardellini, C.; Dipartimento di Scienze della Terra, Universita` di Perugia,Italy; Caliro, S.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Chiarabba, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione CNT, Roma, Italia; Frondini, F.; Dipartimento di Scienze della Terra, Universita` di Perugia, Piazza dell’Universita`, Perugia, Italy

    2013-01-01

    In this work we show that the main springs of the central Apennine transport a total amount of heat of ∼2.2 109 J s−1. Most of this heat (57%) is the result of geothermal warming while the remaining 43% is due to gravitational potential energy dissipation. This result indicates that a large area of the central Apennines is very hot with heat flux values 4300 mWm−2. These values are higher than those measured in the magmatic and famously geothermal provinces of Tuscany and Latium a...

  12. Combined heat supply from heat and power plants with gas-net-heaters and thermo-transformers

    Science.gov (United States)

    Nozdrenko, G. V.; Grigoryeva, O. K.; Frantseva, A. A.

    2012-12-01

    The article considers the process scheme and the cycle of power unit of heat and power plant in the system of combined heat supply with gas-net-heaters and interblock Freon thermo-transformers. Methodology and indicators for evaluation of efficiency of the heating power unit at such heat supply are presented.

  13. New gasification plants for combined heat and power in Denmark

    International Nuclear Information System (INIS)

    In Danish energy planning, the role of combined heat and power generation has been increasing. This has aroused an interest in gasification of biofuels. Several gasification techniques are being developed and the focus is on wood rather than straw. This conference paper describes the present projects in this field and lists the advantages and disadvantages of each technique. The tar content of the gas is a problem. A recent attempt has been made to decompose the tar in biogas plants. Gasification plants are supposed to be commercially available within a few years

  14. Density response to central electron heating: theoretical investigations and experimental observations in ASDEX Upgrade

    International Nuclear Information System (INIS)

    Theory of ion temperature gradient (ITG) and trapped electron modes (TEMs) is applied to the study of particle transport in experimental conditions with central electron heating. It is shown that in the unstable domain of TEMs, the electron thermo diffusive flux is directed outwards. By means of such a flux, a mechanism is identified likely to account for density flattening with central electron heating. Theoretical predictions are compared with experimental observations in ASDEX Upgrade. A parameter domain (including L- and H-mode plasmas) is identified, in which flattening with central electron heating is observed in the experiments. In general, this domain turns out to be the same domain in which the dominant plasma instability is a TEM. On the contrary, the dominant instability is an ITG in plasmas whose density profile is not affected significantly by central electron heating. The flattening predicted by quasi-linear theory for low density L-mode plasmas is too small compared to the experimental observations. At very high density, even when the dominant instability is an ITG, electron heating can provide density flattening, via the coupling with the ion heat channel. In these conditions the anomalous diffusivity increases in response to the increased ion heat flux, while the large collisionality makes the anomalous pinch small and the Ware pinch important. (author)

  15. 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

  16. Application possibilities for nuclear heating plants in the energy system of the Federal Republic of Germany

    International Nuclear Information System (INIS)

    The field of application for nuclear heating plants is the so-called low-temperature heating market. It includes the energy demand for space heating, hot water an low-temperature process heat. The analysis of technical potentials for heating reactors considers two different levels. The structure of the district heating system determines the technical potential in the now existing energy system, it amounts to a total power of 9,8 to 14,3 GWth of heating reactors. For a possible extended use of heating reactors in future which goes beyond the existing district heating system the technical circumstances and the local distribution of the low-temperature heating market define the technical potential which ranges from 126 to 160 GWth on todays basis. The chance of implementing nuclear heating plants is strongly influenced by the economy of their heat generation. The economic situation of heat generation with heating reactors is estimated in comparison to current fossil district heating production systems. In the low-temperature heating market the heat supply by nuclear fed district heating systems is compared to the heat production in houses. Considering the assumptions the analysis indicates that nuclear heating plants can compete with existing fossil heat sources. The analysis shows that heating reactors are an interesting and powerful option for the supply of the district heating market in future. The underlying economic assumptions would allow the use of nuclear heating plants and it seems that they could contribute to reduce the environmental stress. (orig.)

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

    OpenAIRE

    Mirko Grljušić; Vladimir Medica; Nikola Račić

    2014-01-01

    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 ...

  18. Straw fired district heating plants in Denmark. Facts and figures

    International Nuclear Information System (INIS)

    A series of analyses and comparisons of technical, operational and financial and environmental conditions relating to straw-fired district heating and cogeneration plants in Denmark during the period of May 1993 to June 1995. The report provides an insight into the potentials of straw as a source of energy, particularly in the case of countries where the cultivation of cereals represents a major part of the agricultural economy. (AB)

  19. 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.

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

    International Nuclear Information System (INIS)

    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.

  1. Performance analysis of a Kalina cycle for a central receiver solar thermal power plant with direct steam generation

    DEFF Research Database (Denmark)

    Modi, Anish; Haglind, Fredrik

    2014-01-01

    Solar thermal power plants have attracted increasing interest in the past few years - with respect to both the design of the various plant components, and extending the operation hours by employing different types of storage systems. One approach to improve the overall plant efficiency is to use...... without corroding the equipment by using suitable additives with the mixture. The purpose of the study reported here was to investigate if there is any benefit of using a Kalina cycle for a direct steam generation, central receiver solar thermal power plant with high live steam temperature (450 C...... direct steam generation with water/steam as both the heat transfer fluid in the solar receivers and the cycle working fluid. This enables operating the plant with higher turbine inlet temperatures. Available literature suggests that it is feasible to use ammonia-water mixtures at high temperatures...

  2. PLANT COMMUNITIES WITH ARNICA MONTANA IN NATURAL HABITATS FROM THE CENTRAL REGION OF ROMANIAN EASTERN CARPATHIANS

    Directory of Open Access Journals (Sweden)

    Constantin MARDARI

    2015-12-01

    Full Text Available Arnica montana is a species of European Union interest, whose harvest from the wild and exploitation should be made under certain management measures. In Romania it is a vulnerable species due to excessive collection. It is a species with European areal occuring in pastures, meadows, forest glades, shrubs communities of mountain to the subalpine regions and, isolated, up to the alpine belt. Most of the plant communities with Arnica montana are semi-natural, with a floristic composition in which there are numerous rare or threatened species also supporting the need of their conservation. Our study was focused on a numerical classification (hierarchical, using Flexible ß algorithm and Bray-Curtis dissimilarity based on 48 plots, of the plant communities with Arnica montana from the central region of Romanian Eastern Carpathians and on the investigation of the effect of some environmental variables (Ellenberg indicator values, altitude, heat load index on their floristic composition (100 m2 scale. Vegetation – environment relationship was assessed via detrended correspondence analysis and canonical correspondence analysis with Monte Carlo test. Six plant communities with Arnica montana were identified (communities of Festuca rubra with Agrostis capillaris, Festuca nigrescens, Vaccinium myrtillus, Nardus stricta, Vaccinium gaultherioides and Juniperus sibirica with a floristic composition mainly shaped by altitude, temperature and soil nitrogen content. Details related to location and sites characteristics, diagnostic species, floristic composition, presence of other rare or threatened species and Arnica montana abundance were presented for all these plant communities.

  3. Ziar nad Hronom will be heated by an underground heat plant

    International Nuclear Information System (INIS)

    The World Bank and the European Bank for Reconstruction and Development are concerned in co-participation in funding a project for utilising geothermal ground water in heating premises in Ziar nad Hronom. The project implementations costs will be running at U.S.$18 million, of which the two bank institutions would provide for a non-specified part in the form of credit. In heating residential houses, production and commercial infrastructure of Ziar nad Hronom, 72 thousand tonnes of coal are consumed annually to generate 810 TJ heat. By implementing the new project there will be over 100 TJ savings, with a new more efficient distribution hot water network and 39 reconstructed heat exchange station making for effective consumption of heat. The current heat plant will only serve as an auxiliary source under extremely chilly weather conditions with an expected coal consumption of at most 9 thousand tonnes. In addition to cost implications, the geothermal water heating will make a significant contribution through environmental impact. Ecologists calculated that by shutting down the solid fuel burning heat plant the air burden will be reduced by 59 thousand tonnes of carbon dioxide, 290 tonnes of sulfur dioxide, 48 tonnes of nitrogen oxide, 230 tonnes of dust and nearly 12 tonnes of ash. The implementer of the project scheduled to complete in 2001 is a subsidiary of the joint-stock company Zavod SNP - Geothermal, Ltd, Ziar nad Hronom. Aimed at geothermal water sampling in the depth of some 2,500 meters, a trial drill at Ziarska kotlina - site Varticka will last roughly till April 9 1999. The drilling set of Nafta Gbely erected on December 21, 1998 is technically capable of reaching the depth 2,800 meter, just in case that the geothermal water level is lower than the expected 2,500 m. In all In all Nafta Gbely staffs will carry out two production and two reinjection drills. (author)

  4. Evaluation of a sulfur oxide chemical heat storage process for a steam solar electric plant

    Energy Technology Data Exchange (ETDEWEB)

    Dayan, J.; Lynn, S.; Foss, A.

    1979-07-01

    The purpose of this study was to develop and evaluate technically feasible process configurations for the use of the sulfur oxide system, 2 SO/sub 3/ reversible 2 SO/sub 2/ + O/sub 2/, in energy storage. The storage system is coupled with a conventional steam-cycle power plant. Heat for both the power plant and the storage system is supplied during sunlit hours by a field of heliostats focussed on a central solar receiver. When sunlight is not available, the storage system supplies the heat to operate the power plant. A technically feasible, relatively efficient configuration is proposed for incorporating this type of energy storage system into a solar power plant. Complete material and energy balances are presented for a base case that represents a middle range of expected operating conditions. Equipment sizes and costs were estimated for the base case to obtain an approximate value for the cost of the electricity that would be produced from such an installation. In addition, the sensitivity of the efficiency of the system to variations in design and operating conditions was determined for the most important parameters and design details. In the base case the solar tower receives heat at a net rate of 230 MW(t) for a period of eight hours. Daytime electricity is about 30 MW(e). Nighttime generation is at a rate of about 15 MW(e) for a period of sixteen hours. The overall efficiency of converting heat into electricity is about 26%. The total capital cost for the base case is estimated at about $68 million, of which about 67% is for the tower and heliostats, 11% is for the daytime power plant, and 22% is for the storage system. The average cost of the electricity produced for the base case is estimated to be about 11 cents/kW(e)-hr.

  5. Thermodynamic evaluation of liquid metals as heat transfer fluids in concentrated solar power plants

    International Nuclear Information System (INIS)

    Concentrated solar power, and in particular central receiver systems, can play a major role as a renewable energy source with the inherent possibility of including a thermal energy storage subsystem for improving the plant dispatchability. While current commercial projects are dominated by direct steam generation and molten nitrate salt concepts, next-generation systems will require higher operating temperature and larger heat-flux densities in order to increase the efficiency and reduce costs. In that context, liquid metals are proposed in this work as advanced heat transfer fluids that can face those challenges. The main advantages, regarding higher temperature and improved heat transfer performance, are discussed and quantified using simplified models. Indirect thermal storage solutions are proposed for compensating their relatively small heat capacity. Overall, provided that some practical challenges can be overcome, liquid metals present large potential as efficient heat transfer fluids. -- Highlights: • Liquid metals (sodium and LBE) are studied as advanced HTFs. • Larger heat transfer rates lead to an improved receiver performance. • High operating temperature above 1000 °C is possible. • Advanced high-temperature power conversion cycles are investigated

  6. Solar augmentation for process heat with central receiver technology

    Science.gov (United States)

    Kotzé, Johannes P.; du Toit, Philip; Bode, Sebastian J.; Larmuth, James N.; Landman, Willem A.; Gauché, Paul

    2016-05-01

    Coal fired boilers are currently one of the most widespread ways to deliver process heat to industry. John Thompson Boilers (JTB) offer industrial steam supply solutions for industry and utility scale applications in Southern Africa. Transport cost add significant cost to the coal price in locations far from the coal fields in Mpumalanga, Gauteng and Limpopo. The Helio100 project developed a low cost, self-learning, wireless heliostat technology that requires no ground preparation. This is attractive as an augmentation alternative, as it can easily be installed on any open land that a client may have available. This paper explores the techno economic feasibility of solar augmentation for JTB coal fired steam boilers by comparing the fuel savings of a generic 2MW heliostat field at various locations throughout South Africa.

  7. Small mammals as indicators of cryptic plant species diversity in the central Chilean plant endemicity hotspot

    Directory of Open Access Journals (Sweden)

    Meredith Root-Bernstein

    2014-12-01

    Full Text Available Indicator species could help to compensate for a shortfall of knowledge about the diversity and distributions of undersampled and cryptic species. This paper provides background knowledge about the ecological interactions that affect and are affected by herbaceous diversity in central Chile, as part of the indicator species selection process. We focus on the ecosystem engineering role of small mammals, primarily the degu Octodon degus. We also consider the interacting effects of shrubs, trees, avian activity, livestock, slope, and soil quality on herbaceous communities in central Chile. We sampled herbaceous diversity on a private landholding characterized by a mosaic of savanna, grassland and matorral, across a range of degu disturbance intensities. We find that the strongest factors affecting endemic herbaceous diversity are density of degu runways, shrub cover and avian activity. Our results show that the degu, a charismatic and easily identifiable and countable species, could be used as an indicator species to aid potential conservation actions such as private protected area uptake. We map areas in central Chile where degus may indicate endemic plant diversity. This area is larger than expected, and suggests that significant areas of endemic plant communities may still exist, and should be identified and protected.

  8. Power contracting between two different partners. Biogas combined heat and power plants; Energie-Contracting zweier unterschiedlicher Partner. Biogas-Blockheizkraftwerk

    Energy Technology Data Exchange (ETDEWEB)

    Lennartz, Marc Wilhelm

    2013-06-15

    An agricultural consortium in the Eifel (Federal Republic of Germany) has adopted a comprehensive supply of a 7,000 m{sup 2} comprising hotel complex with combined heat and power. The old oil-fired central heating plant has been replaced by a biogas-powered combined heat and power plant (CHP). The hotel was directly connected to the CHP plant by means of a new, approximately 300 m long local heating network including buffer storage. Overall, the hotel operator saves approximately 300,000 L of heating oil annually. The energy demand of the hotel operator will be covered by more than 90 % by means of CHP plants. Thus 20 % of the heating costs is saved.

  9. Designing for the home: a comparative study of support aids for central heating systems.

    Science.gov (United States)

    Sauer, J; Wastell, D G; Schmeink, C

    2009-03-01

    The study examined the influence of different types of enhanced system support on user performance during the management of a central heating system. A computer-based simulation of a central heating system, called CHESS V2.0, was used to model different interface options, providing different support facilities to the user (e.g., historical, predictive, and instructional displays). Seventy-five participants took part in the study and completed a series of operational scenarios under different support conditions. The simulation environment allowed the collection of performance measures (e.g., energy consumption), information sampling, and system control behaviour. Subjective user evaluations of various aspects of the system were also measured. The results showed performance gains for predictive displays whereas no such benefits were observed for the other display types. The data also revealed that status and predictive displays were valued most highly by users. The implications of the findings for designers of central heating systems are discussed. PMID:18433730

  10. System design package for the solar heating and cooling central data processing system

    Science.gov (United States)

    1978-01-01

    The central data processing system provides the resources required to assess the performance of solar heating and cooling systems installed at remote sites. These sites consist of residential, commercial, government, and educational types of buildings, and the solar heating and cooling systems can be hot-water, space heating, cooling, and combinations of these. The instrumentation data associated with these systems will vary according to the application and must be collected, processed, and presented in a form which supports continuity of performance evaluation across all applications. Overall software system requirements were established for use in the central integration facility which transforms raw data collected at remote sites into performance evaluation information for assessing the performance of solar heating and cooling systems.

  11. Investigation of Heat Supply System for Apartment Houses in Zone with Central Thermal Station

    OpenAIRE

    B. A. Bajrashevskij; N. P. Boruchko

    2014-01-01

    A method for calculation of thermal engineering characteristics of central thermal stations (CTS) and heated buildings is developed by organization of systematic processing of measuring results by standard devices. The given method of calculation is used as a basis for the development of mathematical model for a heat supply system with the purpose to try out the investigated modes using a computer. Approximate results of calculations are given in the form of diagrams and tables.

  12. Investigation of Heat Supply System for Apartment Houses in Zone with Central Thermal Station

    Directory of Open Access Journals (Sweden)

    B. A. Bajrashevskij

    2014-06-01

    Full Text Available A method for calculation of thermal engineering characteristics of central thermal stations (CTS and heated buildings is developed by organization of systematic processing of measuring results by standard devices. The given method of calculation is used as a basis for the development of mathematical model for a heat supply system with the purpose to try out the investigated modes using a computer. Approximate results of calculations are given in the form of diagrams and tables.

  13. Heat Flow in Central Japan and its Relations to Geological and Geophysical Features

    OpenAIRE

    Li, Xinyuan; Furukawa, Yoshitsugu; NAGAO, Toshiyasu; Uyeda, Seiya; Suzuki, Hiroyoshi

    1989-01-01

    An investigation on the distribution of surface heat flow in central Japan was carried out using bore-holes of the Kanto-Tokai seismic network of the National Research Center for Disaster Prevention, and holes drilled for geological survey by the Water Resources Development Public Cooperation, the Kanto Regional Construction Bureau and the Chubu Regional Construction Bureau. Topographic effects on heat flow values measured in areas of high topographic variation were taken into account. Eighte...

  14. Design precautions for coupling interfaces between nuclear heating reactor and heating grid or desalination plant

    International Nuclear Information System (INIS)

    Nuclear heating reactor (NHR) has been developed by INET since the early eighties. To achieve its economic viability and safety goal, the NHR is designed with a number of advanced and innovative features, including integrated arrangement, natural circulation, self-pressurized performance, dynamically hydraulic control rod drive and passive safety systems. As a new promising energy system, the NHR can serve for district heating, air conditioning, sea-water desalination and other industrial processes. For all of these applications, it is vital that the design and performance of the coupling interfaces shall insure protection of user ends against radioactive contamination. Therefore, an intermediate circuit is provided in the NHR as a physical barrier, and the operating pressure in the intermediate circuit is higher than that in the primary system. In addition, the radioactivity in the intermediate circuit is monitored continuously, and there are also other protection measures in the design for isolating the intermediate circuit and the heating grid or desalination plant under some emergency conditions. The excellent performance of the above design precautions for the coupling interfaces has been demonstrated by operational practice from the NHR-5, a 5 MW(thermal) experimental NHR, which was put into operation in 1989. This paper presents the main design features of the NHR as well as the special provisions taken in the design for coupling the NHR to the heating grid or desalination plant and some operating experience from the NHR-5. (author)

  15. Waste heat exploitation in processing plants using existing power installations

    International Nuclear Information System (INIS)

    The paper reviews a new procedure patent for the exploitation of low-temperature waste heat in processing plants that consist of steam power installations for the generation of electric energy. The procedure is based on the energy exchange among different processing units, divided into processing stages, so that the input of waste heat at one point substitutes for the consumption of the primary energy medium steam at another point. This enables the utilisation of higher parameter energy accumulated from the, still operationally capable, steam, for the additional expansion on the existing steam turbine within a steam installation. Should this procedure secure a larger quantity of usable steam compared to the quantities processed by the existing steam turbine, then it could be utilised on a new, smaller turbine, which would be built into the other side of the generator, so that it made a unique operational group with the existing one. This would enable the generation of additional electric energy by means of utilising waste heat. Both above mentioned variants can be seen on the process diagram, Figure 1, which is an essential part of this report, while only the first one will be presented in detail for a particular location with a potential energy rationalisation expressed through heat power of around 11 MWt. The main characteristic of this innovation is that its implementation involves minimum investments, as little new equipment would be used with the existing power installations. (author)

  16. Central receiver solar thermal power system, Phase 1: CDRL Item 2, pilot plant preliminary design report. Volume VII. Pilot plant cost and commercial plant cost and performance

    Energy Technology Data Exchange (ETDEWEB)

    Hallet, Jr., R. W.; Gervais, R. L.

    1980-05-01

    Detailed cost and performance data for the proposed tower focus pilot plant and commercial plant are given. The baseline central receiver concept defined by the MDAC team consists of the following features: (A) an external receiver mounted on a tower, and located in a 360/sup 0/ array of sun-tracking heliostats which comprise the collector subsystem. (B) feedwater from the electrical power generation subsystem is pumped through a riser to the receiver, where the feedwater is converted to superheated steam in a single pass through the tubes of the receiver panels. (C) The steam from the receiver is routed through a downcomer to the ground and introduced to a turbine directly for expansion and generation of electricity, and/or to a thermal storage subsystem, where the steam is condensed in charging heat exchangers to heat a dual-medium oil and rock thermal storage unit (TSU). (D) Extended operation after daylight hours is facilitated by discharging the TSU to generate steam for feeding the admission port of the turbine. (E) Overall control of the system is provided by a master control unit, which handles the interactions between subsystems that take place during startup, shutdown, and transitions between operating modes. (WHK)

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

    International Nuclear Information System (INIS)

    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

  18. Influence of plants on heat balance and entropy exchange

    Czech Academy of Sciences Publication Activity Database

    Šír, Miloslav; Weger, J.; Tesař, Miroslav; Lichner, Ľ.

    Praha : VÚKOZ, 2007, s. 177-180. ISBN 978-80-85116-52-6. [Vědecká konference s mezinárodní účastí Strom a květina – součást života. Praha (CZ), 04.09.2007-04.09.2007] R&D Projects: GA AV ČR 1QS200420562; GA AV ČR IAA3042301; GA ČR GA205/05/2312 Institutional research plan: CEZ:AV0Z20600510 Keywords : plant transpiration * phytomass productivity * heat balance * entropy exchange * short rotation coppices Subject RIV: DA - Hydrology ; Limnology

  19. Mathematical modeling of heat transfer between the plant seedling and the environment during a radiation frost

    Directory of Open Access Journals (Sweden)

    Finnikov K.A.

    2010-11-01

    Full Text Available The power of the internal heat source sufficient to maintain a positive temperature of plants during one of the possible form of cold stress - radiation frost was determined with the help of numerical simulation.The simulation of unsteady heat transfer in the soil-plant-air system in the conditions of radiation frost showed that the the ground part of plants is cooling most rapidly, and this process is partially slowed down by the natural-convection heat transfer with warmer air. If the frost is not continuous, the radiative cooling is the main danger for plant. The necessary power of heat-production inside plant that allows it to avoid hypothermia depends both on natural conditions and the size of the plant. For plants with a typical diameter of the stem about 2 mm this heat-production should be from 50 to 100 W / kg. Within 2 hours a total amount of heat about 0.5 MJ / kg in the plant should be allocated. Larger plants will have a smaller surface to mass ratio, and the maintaining of it's temperature will require a lower cost of nutrients per unit, accordingly. Modeling of the influence of plant surface trichomes presence on the process of its cooling showed that the role of trichomes in the protection of plants from hypothermia during radiation frost usually is negative due to the fact that the presence of trichomes increases the radiative heat transfer from the plant and the impediment in air movement near the plant reduces heat flux entering the plant from a warmer air. But in cases where the intensity of heat generation within the plant is sufficient for the maintenance of the plant temperature higher than the air temperature, the presence of trichomes impairs heat transfer from plant to air, and therefore contributes to a better heating of plants.

  20. Modernization and efficiency of heat treatment and heating up plants; Modernisierung und Effizienz von Thermoprozessanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Wendt, Peter [LOI Thermprocess GmbH, Essen (Germany); Kuehn, Friedhelm [Ingenieurbuero fuer Waermebehandlung, Industrieoefen und Energieberatung, Muelheim (Germany)

    2010-10-15

    A goal of this contribution is to show, using examples of the thermal heat treatment industry and the thermal processing units used there (Beltype plants, routary hearth, walking hearth, walking beam, pusher type furnaces and gas carburizing plants as well as case hardening plants), which increases in efficiency within and outside of the actual thermal treatment process and the necessary thermal processing units for the order are available today. From the possibilities of the reduction of energy employment resulting from that, a high potential for the discharge of the environment can be derived. The economic effect concerning energy employment and saving possibilities will also be considered. Concluding, examples of case-hardening show which variants of a change of process present themselves partially in the future, in order to achieve substantial production increases and thus energy cost reductions. (orig.)

  1. Thermal performance of solar district heating plants in Denmark

    DEFF Research Database (Denmark)

    Furbo, Simon; Perers, Bengt; Bava, Federico

    2014-01-01

    collectors mounted on the ground, shows measured yearly thermal performances of the solar heating plants placed in the interval from 313 kWh/m² collector to 493 kWh/m² collector with averages for all plants of 411 kWh/m² collector for 2012 and 450 kWh/m² collector for 2013. Theoretical calculations show that...... for temperature levels higher than about 55°C the thermal performance of a solar collector field based on concentrating tracking solar collectors is higher than the thermal performance of a solar collector field based on flat plate collectors. It is estimated that there are potentials for further...... recommended by parallel theoretical and experimental approach to investigate in detail the thermal performance of differently designed solar collector fields in such a way that their thermal performance can be determined by theoretical calculations in the future. This will be useful in connection with...

  2. Elimination of Oscillations in a Central Heating System using Pump Control

    DEFF Research Database (Denmark)

    Andersen, Palle; Pedersen, Tom Søndergaard; Stoustrup, Jakob; Bidstrup, N.; Svensen, J.; Lovmand, B.

    heating the room. Using the pump speed as an active part in control is it shown that the room temperature may be stabilized in a wider interval of heat demand. The idea is to control the pump speed in a way that keeps the thermostatic valve within a suitable operating area using an estimate of the valve...... position. The position is estimated from the pump terminals, using the pump flow and the pump differential pressure. The concept is tested on a small central heating test bench. The results show that it is possible to stabilize the room temperature even at part load conditions...

  3. Plants adapted to warmer climate do not outperform regional plants during a natural heat wave.

    Science.gov (United States)

    Bucharova, Anna; Durka, Walter; Hermann, Julia-Maria; Hölzel, Norbert; Michalski, Stefan; Kollmann, Johannes; Bossdorf, Oliver

    2016-06-01

    With ongoing climate change, many plant species may not be able to adapt rapidly enough, and some conservation experts are therefore considering to translocate warm-adapted ecotypes to mitigate effects of climate warming. Although this strategy, called assisted migration, is intuitively plausible, most of the support comes from models, whereas experimental evidence is so far scarce. Here we present data on multiple ecotypes of six grassland species, which we grew in four common gardens in Germany during a natural heat wave, with temperatures 1.4-2.0°C higher than the long-term means. In each garden we compared the performance of regional ecotypes with plants from a locality with long-term summer temperatures similar to what the plants experienced during the summer heat wave. We found no difference in performance between regional and warm-adapted plants in four of the six species. In two species, regional ecotypes even outperformed warm-adapted plants, despite elevated temperatures, which suggests that translocating warm-adapted ecotypes may not only lack the desired effect of increased performance but may even have negative consequences. Even if adaptation to climate plays a role, other factors involved in local adaptation, such as biotic interactions, may override it. Based on our results, we cannot advocate assisted migration as a universal tool to enhance the performance of local plant populations and communities during climate change. PMID:27516871

  4. Developing a strategy for improving efficiency in the heating sector in central and eastern Europe

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, A.S. [World Bank, Washington, DC (United States)

    1995-12-31

    Heating is a vital energy service in Central and Eastern Europe, but the current delivery mechanisms are riddled with problems. District heating (DH) in its present technical form and with the present management structures is an inefficient system which produces expensive heat. Customers cannot control it and react to overheating by opening windows, even in winter. DH facilities together with other forms of individual heating are responsible for air pollution, causing severe impacts on the health of urban residents. The issues relating to DH are discussed, the first World Bank activities and experiences with projects in Poland are analyzed, and the cornerstones of a strategy to support future World Bank financing and the development of sound heating policies in CEE are presented.

  5. Performance analysis of a Kalina cycle for a central receiver solar thermal power plant with direct steam generation

    International Nuclear Information System (INIS)

    Solar thermal power plants have attracted increasing interest in the past few years – with respect to both the design of the various plant components, and extending the operation hours by employing different types of storage systems. One approach to improve the overall plant efficiency is to use direct steam generation with water/steam as both the heat transfer fluid in the solar receivers and the cycle working fluid. This enables operating the plant with higher turbine inlet temperatures. Available literature suggests that it is feasible to use ammonia-water mixtures at high temperatures without corroding the equipment by using suitable additives with the mixture. The purpose of the study reported here was to investigate if there is any benefit of using a Kalina cycle for a direct steam generation, central receiver solar thermal power plant with high live steam temperature (450 °C) and pressure (over 100 bar). Thermodynamic performance of the Kalina cycle in terms of the plant exergy efficiency was evaluated and compared with a simple Rankine cycle. The rates of exergy destruction for the different components in the two cycles were also calculated and compared. The results suggest that the simple Rankine cycle exhibits better performance than the Kalina cycle when the heat input is only from the solar receiver. However, when using a two-tank molten-salt storage system as the primary source of heat input, the Kalina cycle showed an advantage over the simple Rankine cycle because of about 33 % reduction in the storage requirement. The solar receiver showed the highest rate of exergy destruction for both the cycles. The rates of exergy destruction in other components of the cycles were found to be highly dependent on the amount of recuperation, and the ammonia mass fraction and pressure at the turbine inlet. - Highlights: •Kalina cycle for a central receiver solar thermal power plant with direct steam generation. •Rankine cycle shows better plant exergy

  6. Heat waves over Central Europe in regional climate models: evaluation and future projections

    Czech Academy of Sciences Publication Activity Database

    Lhotka, Ondřej; Kyselý, Jan

    Berlín: European Meteorological Society, 2015. EMS2015-135. [EMS Annual Meeting /15./ and European Conference on Applied Climatology /12./. 07.09.2015–11.09.2015, Sofia] Institutional support: RVO:68378289 Keywords : regional climate model ( RCM ) * heat waves * Central Europe Subject RIV: DG - Athmosphere Sciences, Meteorology http://meetingorganizer.copernicus.org/EMS2015/EMS2015-135.pdf

  7. Indigenous use and bio-efficacy of medicinal plants in the Rasuwa District, Central Nepal

    OpenAIRE

    Boon Emmanuel K; Asselin Hugo; Uprety Yadav; Yadav Saroj; Shrestha Krishna K

    2010-01-01

    Abstract Background By revealing historical and present plant use, ethnobotany contributes to drug discovery and socioeconomic development. Nepal is a natural storehouse of medicinal plants. Although several ethnobotanical studies were conducted in the country, many areas remain unexplored. Furthermore, few studies have compared indigenous plant use with reported phytochemical and pharmacological properties. Methods Ethnopharmacological data was collected in the Rasuwa district of Central Nep...

  8. Identification and Characterization of Proteins Associated with Plant Tolerance to Heat Stress

    Institute of Scientific and Technical Information of China (English)

    Bingru Huang; Chenping Xu

    2008-01-01

    Heat stress is a major abiotic stress limiting plant growth and productivity in many areas of the world. Understanding mechanisms of plant adaptation to heat stress would facilitate the development of heat-tolerant cultivars for improving productivity in warm climatic regions. Protein metabolism involving protein synthesis and degradation is one of the most sensitive processes to heat stress. Changes in the level and expression pattern of some proteins may play an important role in plant adaptation to heat stress. The identification of stress-responsive proteins and pathways has been facilitated by an increasing number of tools and resources, including two-dimensional electrophoresis and mass spectrometry, and the rapidly expanding nucleotide and amino acid sequence databases. Heat stress may induce or enhance protein expression or cause protein degradation. The induction of heat-responsive proteins, particularly heat shock proteins (HSPs), plays a key role in plant tolerance to heat stress. Protein degradation involving various proteases is also important in regulating plant responses to heat stress. This review provides an overview of recent research on proteomic profiling for the identification of heat-responsive proteins associated with heat tolerance, heat induction and characteristics of HSPs, and protein degradation in relation to plant responses to heat stress.

  9. Refractories in heating plants; Eldfasta material i vaermeanlaeggningar

    Energy Technology Data Exchange (ETDEWEB)

    Westberg, S.B.

    1996-10-01

    This work concerns the demand for development of refractories used as linings in different types of heating plants in Sweden. The treated plants are primarily saw-dust boilers, black-liquor refuse boilers in the pulp industry, biomass fired fluidised bed boilers and municipal-waste incinerators. The use, function, development and development demand varies largely between the different types of plants. A common trend is, however, that increasingly more higher-grade materials are being used and that other factors than wear rate determine the materials selection. The use of refractories in saw-dust boilers is restricted to the immediate vicinity of the burner. Occurring damages are attended yearly. The design of the lining in municipal-waste incinerators is largely determined by the combustion conditions and the ability to protect the metal from the corrosive flue gas. The introduction of cooled membrane-walls has resulted in extensive use of silicon-carbide based materials due to inherently high thermal conductivity and usually high abrasion resistance. From a durability point of view, a smooth surface and high thermal conductivity is desired. The refractories in a black liquor refuse boiler is attacked by the molten alkali-compounds. These compounds are able to dissolve glass, most minerals and attack cement. Compound materials and sprayed protective surface coatings are often used where possible to decrease the amount of refractories used. High quality corrosion resistant low-cement materials with high content of alumina is used. 25 refs, 4 figs

  10. Costs and water quality effects of wastewater treatment plant centralization

    Energy Technology Data Exchange (ETDEWEB)

    Macal, C.M.; Broomfield, B.J.

    1980-01-01

    The costs and water quality impacts of two regional configurations of municipal wastewater treatment plants in Northeastern Illinois are compared. In one configuration, several small treatment plants are consolidated into a smaller number of regional facilities. In the other, the smaller plants continue to operate. Costs for modifying the plants to obtain various levels of pollutant removal are estimated using a simulation model that considers the type of equipment existing at the plants and the costs of modifying that equipment to obtain a range of effluent levels for various pollutants. A dynamic water-quality/hydrology simulation model is used to determine the water quality effects of the various treatment technologies and pollutant levels. Cost and water quality data are combined and the cost-effectiveness of the two treatment configurations is compared. The regionalized treatment-plant configuration is found to be the more cost-effective.

  11. Heat engineering problems of designing boiler units of power plants with heat emission superstructure

    Energy Technology Data Exchange (ETDEWEB)

    Berezintes, P.A.; Shvarts, A.L.

    1981-06-01

    In connection with the achievements in the development of thermoemission converters, the problem of their application at steam power plants as a superstructure is posed. The efficiency of such a combined cycle is discussed. A design diagram including a power unit with an 800 MW steam turbine with standard supercritical steam parameters is considered. The main constraint on the efficiency of the combined cycle with a solid fuel-fired boiler is the level of air preheating. This is due to the slagging properties of ash and heat-resistance and chemical resistance of materials used for air preheaters.

  12. Energy and exergy analysis of fossil plant and heat pump building heating system at two different dead-state temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Lohani, S.P. [Kathmandu University, Dhulikhel (Nepal)

    2010-08-15

    In this paper, we deal with the energy and exergy analysis of a fossil plant and ground and air source heat pump building heating system at two different dead-state temperatures. A zone model of a building with natural ventilation is considered and heat is being supplied by condensing boiler. The same zone model is applied for heat pump building heating system. Since energy and exergy demand are key parameters to see which system is efficient at what reference temperature, we did a study on the influence of energy and exergy efficiencies. In this regard, a commercial software package IDA-ICE program is used for calculation of fossil plant heating system, however, there is no inbuilt simulation model for heat pumps in IDA-ICE, different COP (coefficient of performance) curves of the earlier studies of heat pumps are taken into account for the evaluation of the heat pump input and output energy. The outcome of the energy and exergy flow analysis at two different dead-state temperatures revealed that the ground source heat pumps with ambient reference have better performance against all ground reference systems as well as fossil plant (conventional system) and air source heat pumps with ambient reference. (author)

  13. Nuclear heat generating plants - technical concepts and market potentials. Chapter 8

    International Nuclear Information System (INIS)

    To determine the advantages and disadvantages of different heat generating systems, a comparison is made between nuclear heat generating plants and competing heat generating systems. Nuclear heat generating plant concepts in practice have to compete with a wide range of existing and new fossil heat generating technologies of the most different capacities, ranging from combined heat and power generation to individual heating in one-family houses. Heat generation costs are calculated by means of a dynamic annuity method from an economic point of view. The development of real prices of fossil energy sources is based on two scenarios characterized as follows: scenario I - insignificant price increase by the year 2000, then stagnant; scenario II - moderate price increase by the year 2010, then stagnant. As a result of that systems comparison it can be stated that the considered nuclear heat generating plants may be an interesting competitive heat generation option, provided the assumptions on which the study is based can be implemented. This applies especially to investment costs. At the same time those plants contribute to a diversification of energy source options on the heat market. Their use leads to a reduction of fossil fuel imports, increasing at the same time short- and long-term supply guarantees. If nuclear heat generating plants substitute fossil heat generating plants, or render the construction of new ones superfluous, they contribute to avoiding chemical air pollutants. (orig./UA)

  14. Integration of centralized biogas plant in cold-snowy region in Japan

    OpenAIRE

    Umetsu K.; Ying C.; Kikuchi S.; Iwasaki M.; Takeuchi Y.; Oi M.; Shiroishi K.; Uematsu T.; Yasui S.

    2011-01-01

    A centralized biogas plant was built in Shikaoi town, Hokkaido, Japan to treat manure from 1320 cattle heads. The biogas plant was designed to operate at a feeding amount of 85.8 t/day, a hydraulic retention time (HRT) of 37 days and at a digester temperature of 38 °C. In this study, the operational performance of biogas plant, utilization of digested slurry and economic balance were investigated. Since the working conditions of the plant became stable, the...

  15. Concept of a HTR modular plant for generation of process heat in a chemical plant

    International Nuclear Information System (INIS)

    This final report summarizes the results of a preliminary study on behalf of Buna AG and Leunawerke AG. With regard to the individual situations the study investigated the conditions for modular HTR-2 reactors to cover on-site process heat and electric power demands. HTR-2 reactor erection and operation were analyzed for their economic efficiency compared with fossil-fuel power plants. Considering the prospective product lines, the technical and economic conditions were developed in close cooperation with Buna AG and Leunawerke AG. The study focused on the technical integration of modular HTR reactors into plants with regard to safety concepts, on planning, acceptance and erection concepts which largely exclude uncalculable scheduling and financial risks, and on comparative economic analyses with regard to fossil-fuel power plants. (orig.)

  16. A novel system for in situ determination of heat tolerance of plants: first results on alpine dwarf shrubs

    OpenAIRE

    Buchner, Othmar; Karadar, Matthias; Bauer, Ines; Neuner, Gilbert

    2013-01-01

    Background Heat stress and heat damage to plants gain globally increasing importance for crop production and plant survival in endangered habitats. Therefore the knowledge of heat tolerance of plants is of great interest. As many heat tolerance measurement procedures require detachment of plants and protocols expose samples to various heat temperatures in darkness, the ecological relevance of such results may be doubted. To overcome these constraints we designed a novel field compatible Heat ...

  17. Central Control of Heat Pump for Smart Grid Purposes Tested on Single Family Houses

    DEFF Research Database (Denmark)

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

    2013-01-01

    A challenge in Denmark in the near future is to balance the electrical grid due to a large increase in the renewable energy production mainly from wind turbines. In this work a central control system using heat pumps in single family houses to help balancing the grid is investigated. The central...... MPC controller optimises the hour by hour energy consumption based on energy prices. A server based solution is tested using inhabited single family houses showing ability to move consumption with minor indoor temperature variations....

  18. Central Data Processing System (CDPS) users manual: solar heating and cooling program

    Energy Technology Data Exchange (ETDEWEB)

    1976-09-01

    The Central Data Processing System (CDPS) provides the software and data base management system required to assess the performance of solar heating and cooling systems installed at multiple remote sites. The instrumentation data associated with these systems is collected, processed, and presented in a form which supports continuity of performance evaluation across all applications. The CDPS consists of three major elements: communication interface computer, central data processing computer, and performance evaluation data base. The CDPS Users Manual identifies users of the performance data base, procedures for operation, and guidelines for software maintenance. The manual also defines the output capabilities of the CDPS in support of external users of the system.

  19. An examination of heat rate improvements due to waste heat integration in an oxycombustion pulverized coal power plant

    Science.gov (United States)

    Charles, Joshua M.

    Oxyfuel, or oxycombustion, technology has been proposed as one carbon capture technology for coal-fired power plants. An oxycombustion plant would fire coal in an oxidizer consisting primarily of CO2, oxygen, and water vapor. Flue gas with high CO2 concentrations is produced and can be compressed for sequestration. Since this compression generates large amounts of heat, it was theorized that this heat could be utilized elsewhere in the plant. Process models of the oxycombustion boiler, steam cycle, and compressors were created in ASPEN Plus and Excel to test this hypothesis. Using these models, heat from compression stages was integrated to the flue gas recirculation heater, feedwater heaters, and to a fluidized bed coal dryer. All possible combinations of these heat sinks were examined, with improvements in coal flow rate, Qcoal, net power, and unit heat rate being noted. These improvements would help offset the large efficiency impacts inherent to oxycombustion technology.

  20. The Molecular Evolution of the Small Heat-Shock Proteins in Plants

    OpenAIRE

    Waters, E. R.

    1995-01-01

    The small heat-shock proteins have undergone a tremendous diversification in plants; whereas only a single small heat-shock protein is found in fungi and many animals, over 20 different small heat-shock proteins are found in higher plants. The small heat-shock proteins in plants have diversified in both sequence and cellular localization and are encoded by at least five gene families. In this study, 44 small heat-shock protein DNA and amino acid sequences were examined, using both phylogeneti...

  1. Utilization of low-temperature heat out of Philippsburg nuclear power plant and concepts for economical district heating systems

    International Nuclear Information System (INIS)

    The project had to develop technical and economical concepts of utilization of low temperature heat and waste heat out of the Philippsburg nuclear power plant. Three general techniques turned out to be feasible and economical: - District heating for the eastern part of the town by extraction of 18 MW (thermal output) out of the low pressure part of the condensing turbine (total load of the district heating system is 37 MW), - Supply of greenhouses (total area of 20.000 m2 under glas) close to the plant by waste heat out of the condensing - turbine and generator-cooling-circuit (8 MW, 300C), - Supply of low-temperature waste heat out of the condensing circuit (4 MW, 200C) for fish-growing-basins. (orig.)

  2. 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.

  3. Objective validation of central sensitization in the rat UVB and heat rekindling model

    OpenAIRE

    Weerasinghe, NS; Lumb, BM; Apps, R; Koutsikou, S; Murrell, JC

    2014-01-01

    Background The UVB and heat rekindling (UVB/HR) model shows potential as a translatable inflammatory pain model. However, the occurrence of central sensitization in this model, a fundamental mechanism underlying chronic pain, has been debated. Face, construct and predictive validity are key requisites of animal models; electromyogram (EMG) recordings were utilized to objectively demonstrate validity of the rat UVB/HR model. Methods The UVB/HR model was induced on the heel of the hind paw unde...

  4. Preliminary design review package for the solar heating and cooling central data processing system

    Science.gov (United States)

    1976-01-01

    The Central Data Processing System (CDPS) is designed to transform the raw data collected at remote sites into performance evaluation information for assessing the performance of solar heating and cooling systems. Software requirements for the CDPS are described. The programming standards to be used in development, documentation, and maintenance of the software are discussed along with the CDPS operations approach in support of daily data collection and processing.

  5. Experimental pneumococcal meningitis causes central nervous system pathology without inducing the 72-kd heat shock protein.

    OpenAIRE

    Täuber, M G; Kennedy, S L; Tureen, J H; Lowenstein, D. H.

    1992-01-01

    We examined whether experimental pneumococcal meningitis induced the 72-kd heat shock protein (HSP72), a sensitive marker of neuronal stress in other models of central nervous system (CNS) injury. Brain injury was characterized by vasculitis, cerebritis, and abscess formation in the cortex of infected animals. The extent of these changes correlated with the size of the inoculum (P less than 0.003) and with pathophysiologic parameters of disease severity, i.e., cerebrospinal fluid (CSF) lactat...

  6. Preliminary design of the Carrisa Plains solar central receiver power plant. Volume III, Book 1. Design description

    Energy Technology Data Exchange (ETDEWEB)

    1983-12-31

    The design of the 30 MWe central receiver solar power plant to be located at Carrisa Plains, San Luis Obispo County, California, is summarized. The plant uses a vertical flat-panel (billboard solar receiver located at the top of a tower to collect solar energy redirected by approximately 1900 heliostats located to the north of the tower. The solar energy is used to heat liquid sodium pumped from ground level from 610 to 1050/sup 0/F. The power conversion system is a non-reheat system, cost-effective at this size level, and designed for high-efficiency performance in an application requiring daily startup. Successful completion of this project will lead to power generation starting in 1986. This report discusses in detail the design of the collector system, heat transport system, thermal storage subsystem, heat transport loop, steam generation subsystem, electrical, instrumentation, and control systems, power conversion system, master control system, and balance of plant. The performance, facility cost estimate and economic analysis, and development plan are also discussed.

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

    OpenAIRE

    Mirko Grljušić; Vladimir Medica; Gojmir Radica

    2015-01-01

    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. ...

  8. CONCRETE STORAGE FOR SOLAR THERMAL POWER PLANTS AND INDUSTRIAL PROCESS HEAT

    OpenAIRE

    Laing, Doerte; Lehmann, Dorothea; Bahl, Carsten

    2008-01-01

    Economic storage of thermal energy is a technological key issue for solar thermal power plants and industrial waste heat recovery. Systems using single phase heat transfer fluids like thermal oil, pressurized water, air or superheated steam, demand storage systems for sensible heat. A sensible heat storage system using concrete as storage material has been developed by Ed. Züblin AG and DLR. A major focus was the cost reduction of the heat exchanger and the high temperature concrete storage m...

  9. HEAT TRANSFORMATION IN THE PLANT FOR INTEGRATED ENERGY SUPPLY BY LITHIUM BROMIDE ABSORPTION MACHINE

    OpenAIRE

    А.М. Радченко; Остапенко, О. В.

    2015-01-01

    The efficiency of waste heat transformation from gas engines in the plant forintegratedenergysupply by lithium bromideabsorption refrigerating machine was analyzed. Such gas engines are equipped with heat exchangers for producing hot water from the engine recoverable heat. The waste heat from gas engine jacket and lubricant oil cooling water, scavenge gas-air mixture and exhaust gas are used to produce hot water with the temperature of about 90 °С as heating source for absorption chiller. The...

  10. Performance improvement of a 330MWe power plant by flue gas heat recovery system

    OpenAIRE

    Xu Changchun; Xu Min; Zhao Ming; Liang Junyu; Sai Juncong; Qiu Yalin; Xiang Wenguo

    2016-01-01

    In a utility boiler, the most heat loss is from the exhaust flue gas. In order to reduce the exhaust flue gas temperature and further boost the plant efficiency, an improved indirect flue gas heat recovery system and an additional economizer system are proposed. The waste heat of flue gas is used for high-pressure condensate regeneration heating. This reduces high pressure steam extraction from steam turbine and more power is generated. The waste heat recov...

  11. Operation Performance of Central Solar Heating System with Seasonal Storage Water Tank in Harbin

    Institute of Scientific and Technical Information of China (English)

    YE Ling; JIANG Yi-qiang; YAO Yang; ZHANG Shi-cong

    2009-01-01

    This paper presented a preliminary research on the central solar heating system with seasonal stor-age(CSHSSS)used in cold climate in China.A mathematical model of the solar energy seasonal storage water tank used in the central solar heating system was firstly developed based on energy conservation.This was fol-lowed by the simulation of the CSHSSS used in a two-floor villa in Harbin,and analysis of the impacts on storage water temperature of tank volume,solar collector area,tank burial depth,insulation thickness around the tank,etc.The results show there is a relatively economical tank volume to optimize the system efficiency,which de-creases with increasing tank volume at the constant collector area,and increases with increasing collector area at the constant tank volume.Furthermore,the insulation thickness has obvious effect on avoiding heat loss,while the tank burial depth doesn't.In addition-the relationship between the solar collector efficiency and storage wa-ter temperature is also obtained,it decreases quickly with increasing storing water temperature,and then in-creases slowly after starting space heating system.These may be helpful for relevant design and optimization in cold climates in China and all over the world.

  12. Operation and Maintenance Manual for the Central Facilities Area Sewage Treatment Plant

    Energy Technology Data Exchange (ETDEWEB)

    Norm Stanley

    2011-02-01

    This Operation and Maintenance Manual lists operator and management responsibilities, permit standards, general operating procedures, maintenance requirements and monitoring methods for the Sewage Treatment Plant at the Central Facilities Area at the Idaho National Laboratory. The manual is required by the Municipal Wastewater Reuse Permit (LA-000141-03) the sewage treatment plant.

  13. Puertollano IGCC Power Plant; Central de Gasificacion Integrada en Ciclo Combinado de Puertollano

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The Puertollano IGCC Power Plant, rated 335 MW and located in Puertollano, Ciudad Real, in the central area of Spain, is a project led by ELCOGAS, a company incorporated by the European utilities ENDESA, ELECTRICITE DE FRANCE, IBERDROLA HIDROCANTABRICO ELECTRICIDADE DE PURTUGAL, ENEL and NATIONAL POWER and the technology and equipment suppliers SIEMENS, KRUPP UHDE and BABCOCK WILCOX ESPANOLA. IGCC technology is based in a process of coal gasification to obtain a clean combustion synthetic gas, integrated with a combined cycle, agas and steam, electricity-generating unit. The energy efficiency which is aimed to achieve at the Plant is 46% in ISO conditions. The Gasification unit uses the process of pressurised entrained flow for coal gasification. The gas is produced by the reaction of coal with oxygen at high temperatures, of up to 1600 degree centigree. This process is capable of gasifying a wide variety of types and qualities of coal for the production of a synthetic fuel gas. In the case of Puertollano, the raw fuel is a 50% mixture by weight of local coal and petroleum coke. The oxygen needed in the process and the nitrogen used for covering the fuel is generated in the Air Separation. The Gas Cleaning and Sulphur Recovery Unit clean the gases from contaminants and solid particles before to send them to the Gas Turbine. The clean gas is burnt in gas turbine of the Combined Cycle Plant, producing electricity. The exhaust gases feed a heat recovery steam generator, which produces steam used to generate additional electricity in a conventional steam turbine. The gas turbine is capable of operating both with synthetic gas and with natural gas, allowing operation flexibility. The net output of the plant up to December 1999 was 3.061 GWh, from them 344 GWh were produced with synthetic gas. This project has an important technological value, being the first power plant which uses coal gasification to feed a combined cycle in Spain and being also the biggest power plant

  14. Comparison of LCA results of low temperature heat plant using electric heat pump, absorption heat pump and gas-fired boiler

    International Nuclear Information System (INIS)

    Highlights: • Usage of geothermal heat pump can bring environmental benefits. • The lowest environmental impact for whole life cycle is obtained for absorption heat pump. • The value of heat pump COP has a significant influence on environmental impact. • In case of coal based power generation the damage to human health is significant. - Abstract: This study compares the life cycle impacts of three heating plant systems which differ in their source of energy and the type of system. The following heating systems are considered: electric water-water heat pump, absorption water-water heat pump and natural gas fired boiler. The heat source for heat pump systems is low temperature geothermal source with temperature below 20 °C and spontaneous outflow 24 m3/h. It is assumed that the heat pumps and boiler are working in monovalent system. The analysis was carried out for heat networks temperature characteristic at 50/40 °C which is changing with outdoor temperature during heating season. The environmental life cycle impact is evaluated within life cycle assessment methodological framework. The method used for life cycle assessment is eco-indicator ‘99. The functional unit is defined as heating plant system with given amount of heat to be delivered to meet local heat demand in assumed average season. The data describing heating plant system is derived from literature and energy analysis of these systems. The data describing the preceding life cycle phases: extraction of raw materials and fuels, production of heating devices and their transportation is taken from Ecoinvent 2.0 life cycle inventory database. The results were analyzed on three levels of indicators: single score indicator, damage category indicators and impact category indicator. The indicators were calculated for characterization, normalization and weighting phases as well. SimaPro 7.3.2 is the software used to model the systems’ life cycle. The study shows that heating plants using a low

  15. Remote and Centralized Monitoring of PV Power Plants

    DEFF Research Database (Denmark)

    Kopacz, Csaba; Spataru, Sergiu; Sera, Dezso;

    2014-01-01

    measurements from the inverters within each PV plant. The monitoring software stores the PV measurements in a data warehouse optimized for managing and data mining large amounts of data, from where it can be later visualized, analyzed and exported. By combining PV production measurements data with I-V curve...

  16. Report of results of benchmarking survey of central heating operations at NASA centers and various corporations

    Science.gov (United States)

    Hoffman, Thomas R.

    1995-08-01

    In recent years, Total Quality Management has swept across the country. Many companies and the Government have started looking at every aspect on how business is done and how money is spent. The idea or goal is to provide a service that is better, faster and cheaper. The first step in this process is to document or measure the process or operation as it stands now. For Lewis Research Center, this report is the first step in the analysis of heating plant operations. This report establishes the original benchmark that can be referred to in the future. The report also provides a comparison to other organization's heating plants to help in the brainstorming of new ideas. The next step is to propose and implement changes that would meet the goals as mentioned above. After the changes have been implemented the measuring process starts over again. This provides for a continuous improvement process.

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

    International Nuclear Information System (INIS)

    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)

  18. Application of multi-criteria decision-making model for choice of the optimal solution for meeting heat demand in the centralized supply system in Belgrade

    International Nuclear Information System (INIS)

    The expected growth of living standard, number of inhabitants and development of technology, industry and agriculture will cause a significant increase of energy consumption in cities. Three scenarios of energy sector development until 2030 and corresponding energy consumption for the city of Belgrade are analyzed in this paper. These scenarios consider different level of economic development, investments in energy sector, substitution of fossil fuels, introduction of renewable energy sources and implementation of energy efficiency measures. The proposed model for selection of optimal district heating system compares different options for fulfilling expected new heat demand through eight criteria for each scenario. Proposed options are combination of different energy sources and technologies for their use. The criteria weights are set according to Serbian economy and energy position. The criteria include financial aspects, environmental impact and availability of energy. Multi-criteria method ELECTRE (ELimination Et Choix Traduisant la REalite) is used as a tool for obtaining the optimal option. It is concluded that combination of CHP (combined heat and power) plant and centralized use of geothermal energy is optimal choice in the optimistic scenario. In the pessimistic and business as usual scenario the optimal option is combination of new gas boilers and centralized use of geothermal energy. - Highlights: • Three scenarios for meeting new heat demand are developed and assessed. • Constructing CHP (combined heat and power) is desirable in case of significant electricity price growth. • In all scenarios the chosen option includes using geothermal energy for heating

  19. Prototype plant for nuclear process heat (PNP) - operation of the pilot plant for hydrogasification of coal

    International Nuclear Information System (INIS)

    The Rheinische Braunkohlenwerke AG developed the process of hydrogasification of coal in a fluidized bed for generation of SNG. On basis of test results obtained in a semi-technical pilot plant of a through-put of 250 kg/h dried coal a large pilot plant was erected processing 10 t/h dried brown coal. This plant was on stream for about 14700 h, of which about 7800 h were with gasifier operation; during this time about 38000 t of dried brown coal of the Rhenish district were processed containing 4 to 25% of ash. At pressures of 60 to 120 bar and temperatures of 800 to 9350C carbon conversion rates up to 81 percent and methane amounts of 5000 m3 (STP)/h were reached. The decisive parameter for methane generation was the hydrogen/coal-ratio. Even at high moisture contents, usually diminishing the methane yield from the coal essentially, by high hydrogen/coal-ratios high methane yields could be obtained. The gasifier itself caused no troubles during the total time operation. Difficulties with the original design of the residual char cooler could be overcome by change-over from water injection to liquid carbon dioxide. The design of the heat recovery system proved well. Alltogether so the size increasement of the gasifier from the semi-technical to the large pilot plant as well as the harmonization of gas generation and gas refining was proved. (orig.) With 20 refs., 20 tabs., 81 figs

  20. Solar Pilot Plant, Phase I. Preliminary design report. Volume II, Book 2. Central receiver optical model users manual. CDRL item 2. [HELIAKI code

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-05-01

    HELIAKI is a FORTRAN computer program which simulates the optical/thermal performance of a central receiver solar thermal power plant for the dynamic conversion of solar-generated heat to electricity. The solar power plant which this program simulates consists of a field of individual sun tracking mirror units, or heliostats, redirecting sunlight into a cavity, called the receiver, mounted atop a tower. The program calculates the power retained by that cavity receiver at any point in time or the energy into the receiver over a year's time using a Monte Carlo ray trace technique to solve the multiple integral equations. An artist's concept of this plant is shown.

  1. Cost to deliver sweet sorghum fermentables to a central plant

    International Nuclear Information System (INIS)

    The major obstacle to a sweet sorghum-for-ethanol industry in the Piedmont of Virginia is the short harvest season of eight weeks. A Piedmont harvesting system is described that will enable the Piedmont to compete with Louisiana in production of sweet sorghum for ethanol. The cost to supply feedstock (up to the point fermentation begins) for a one million GPY ethanol plant was estimated to be $2.35/gal expected ethanol yield. This amount compared favorably with two other options

  2. EFFICIENCY OF THE USE OF HEAT PUMPS ON THE CHP PLANTS

    Directory of Open Access Journals (Sweden)

    Juravleov A.A.

    2007-04-01

    Full Text Available The work is dedicated to the calculus of the efficiency of the use of heat pumps on the CHP plants. There are presented the interdependences between the pay-back period and NPV of heat pump and the price of 1 kWt of thermal power of heat pump and of the tariff of electricity.

  3. Efficiency Growth of Combined-cycle Cogeneration Plant with the Heat Supply System

    OpenAIRE

    Denysova Alla; Mazurenko A.S.; Denysova Anastasiia

    2015-01-01

    Energy efficiency of modern technologies of the combined production of heat and electricity and ways of energy saving on base of recycling secondary energy sources has been estimated. It is shown that the most effective for cogeneration are combined-cycle plants. The rational scheme of interaction of combined-cycle cogeneration plant with heat supply system has been offered. Theoretical bases of interaction of main installation with a contour of heat and hot water supply system has been devel...

  4. Experience with the operation of a solar central heating system in Friedrichshafen/Wiggenhausen-Sued; Betriebserfahrungen mit der solaren Nahwaermeversorgung in Friedrichshafen/Wiggenhausen-Sued

    Energy Technology Data Exchange (ETDEWEB)

    Stanzel, B.; Gawantka, F. [Technische Werke Friedrichshafen GmbH, Friedrichshafen (Germany)

    1998-12-31

    The ideas, concepts and pilot plants for solar central heating systems developed by the Institute for Thermodynamics and Thermal Engineering of Stuttgart University were implemented by the Steinbeis-Transfer Centre for Energy, Building and Solar Engineering. In order to improve the economic efficiency of solar central heating with long-term storage a pilot plant with a heat storage tank of 12,000 cubic metres was built in Wiggenhausen-Sued. The `Technische Werke Friedrichshafen` (TWF) is in charge of the project `Solar City Wiggenhausen-Sued`. This company built the plant and also operates and maintains it. (orig.) [Deutsch] Die Ideen, Konzepte und erste Pilotanlagen zur solaren Nahwaerme werden seit Mitte der achtziger Jahre vom Institut fuer Thermodynamik und Waermetechnik (ITW) der Universitaet Stuttgart entwickelt und vom Steinbeis-Transferzentrum Energie-, Gebaeude- und Solartechnik umgesetzt. Um die solare Nahwaermeversorgung mit Langzeit-Waermespeicher der Wirtschaftlichkeit etwas naeher zu bringen, wurde eine Pilotanlage mit einem 12.000 m{sup 3} grossen Waermespeicher in Wiggenhausen-Sued gebaut. Mit diesem Pilotprojekt soll neben der technischen Durchfuehrbarkeit die Kostendegression durch steigende Anlagengroesse nachgewiesen werden. Als Energiedienstleistungsunternehmen hat die Technische Werke Friedrichshafen GmbH (TWF) die technische und kaufmaennische Durchfuehrung des Projektes `Solarstadt Wiggenhausen-Sued` uebernommen. Sie errichtete, betreibt und wartet die Anlage. (orig.)

  5. Studying heat integration options for steam-gas power plants retrofitted with CO2 post-combustion capture

    International Nuclear Information System (INIS)

    Electricity generation from fossil fuels has become a focal point of energy and climate change policies due to its central role in modern economics and its leading contribution to greenhouse gas emissions. Carbon capture and sequestration (CCS) is regarded by the International Energy Agency as an essential part of the technology portfolio for carbon mitigation, as it can significantly reduce CO2 emissions while ensuring electricity generation from fossil fuel power plants. This paper studies the retrofit of natural gas combined cycles (NGCCs) with an amine-based post-combustion carbon capture system. NGCCs with differently rated capacities were analysed under the assumptions that the heat requirement of the capture system was provided via a steam extraction upstream of the low-pressure steam turbine or by an auxiliary unit that was able to reduce the power plant derating related to the energy needs of the CCS system. Different types of auxiliary units were investigated based on power plant size, including a gas turbine cogeneration plant and a supplementary firing unit or boiler fed by natural gas or biomass. Energy and economic analyses were performed in order to evaluate the impact of type and layout of retrofit option on energy, environmental and economic performance of NGCCs with the CCS system. - Highlights: • Steam-gas power plants with an amine-based CO2 capture unit are examined. • The study concerns three combined cycles with different capacity and plant layout. • Several options to fulfil the heat requirement of the CCS system are explored. • Steam extraction significantly reduces the capacity of steam-gas power plant. • An auxiliary combined heat and power unit allows to reduce power plant derating

  6. RESTful M2M gateway for remote wireless monitoring for district central heating networks.

    Science.gov (United States)

    Cheng, Bo; Wei, Zesan

    2014-01-01

    In recent years, the increased interest in energy conservation and environmental protection, combined with the development of modern communication and computer technology, has resulted in the replacement of distributed heating by central heating in urban areas. This paper proposes a Representational State Transfer (REST) Machine-to-Machine (M2M) gateway for wireless remote monitoring for a district central heating network. In particular, we focus on the resource-oriented RESTful M2M gateway architecture, and present an uniform devices abstraction approach based on Open Service Gateway Initiative (OSGi) technology, and implement the resource mapping mechanism between resource address mapping mechanism between RESTful resources and the physical sensor devices, and present the buffer queue combined with polling method to implement the data scheduling and Quality of Service (QoS) guarantee, and also give the RESTful M2M gateway open service Application Programming Interface (API) set. The performance has been measured and analyzed. Finally, the conclusions and future work are presented. PMID:25436650

  7. Enhanced biogas recovery by applying post-digestion in large-scale centralized biogas plants

    DEFF Research Database (Denmark)

    Angelidaki, Irini; Hejnfelt, Anette; Ellegaard, L.

    2006-01-01

    The main objective of this study was to investigate the degradation efficiency of centralized biogas plants and provide guidance for the design of more efficient digester and post-digestion systems. These centralized biogas plants in Denmark digest manure together with organic waste from the food...... industry to generate biogas, which is used for electricity and thermal energy. A total of 20 such plants are currently active in Denmark, most of which were included in the investigation. From the plants, samples were obtained from various steps of the process. Samples were analysed and the residual biogas...... potential determined by batch post-digestion at various temperature levels. Results were correlated with plant characteristics and production statistics in order to judge the efficiency of various digestion concepts. A simplified model based on a two-step biogas production process was developed...

  8. Nuclear power plant insurance in Central and Eastern Europe

    International Nuclear Information System (INIS)

    It was only after the decay of the Warsaw Pact, accompanied by emerging democratic structures and abolishment of the state monopolies, that an insurance market with private insurance companies had a chance to develop in these countries. West European insurance companies and their associations assisted and participated in this development by sending representatives and establishing branch offices. The paper reviews the current insurance regime for nuclear power plants of the Russian design types from the angle of international insurers as well as German insurance companies, referring to achievements so far and the foreseeable development. (orig./CB)

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

    International Nuclear Information System (INIS)

    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

  10. Nitrogen Removal Efficiency at Centralized Domestic Wastewater Treatment Plants in Bangkok, Thailand

    Directory of Open Access Journals (Sweden)

    Pongsak Noophan

    2009-07-01

    Full Text Available In this study, influents and effluents from centralized domestic wastewater treatment systems in Bangkok (Rattanakosin, Dindaeng, Chongnonsi, Nongkhaem, and Jatujak were randomly collected in order to measure organic nitrogen plus ammonium-nitrogen (total Kjeldahl nitrogen, total organic carbon, total suspended solids, and total volatile suspended solids by using Standard Methods for the Examination of Water and Wastewater 1998. Characteristics of influent and effluent (primary data of the centralized domestic wastewater treatment system from the Drainage and Sewerage Department of Bangkok Metropolitan Administration were used to analyze efficiency of systems. Fluorescent in situ hybridization (FISH was used to identify specific nitrifying bacteria (ammonium oxidizing bacteria specific for Nitrosomonas spp. and nitrite oxidizing bacteria specific for Nitrobacter spp. and Nitrospira spp.. Although Nitrosomonas spp. and Nitrobacter spp. were found, Nitrospira spp. was most prevalent in the aeration tank of centralized wastewater treatment systems. Almost all of the centralized domestic wastewater treatment plants in Bangkok are designed for activated sludge type biological nutrient removal (BNR. However, low efficiency nitrogen removal was found at centralized wastewater treatment plants in Bangkok. Influent ratio of TOC:N at centralized treatment plant is less than 2.5. Centralized wastewater treatment systems have not always been used suitability and used successfully in some areas of Bangkok Thailand.

  11. ASESSMENT OF STREET PLANTINGS ON THE EXAMPLE OF SOCHI CENTRAL REGION

    Directory of Open Access Journals (Sweden)

    Kunina V. A.

    2015-12-01

    Full Text Available The article deals with the topical issues of ornamental woody plants used in street landscaping of Sochi Central district. It presents the quantitative composition of these species, numbering 12181 specimens. With the scale, modified for the regional conditions, we carried out an analysis of the studied plantations and their state, which revealed that weakened plants were predominant - 72.48%. Healthy plants make up over 20%. The lowest number of the specimen was recorded among the dead plants (0,26%. The analysis was carried out for all species according to the state categories. For instance, structure-forming species selected for further studies, were analyzed this way, including a large part of plants that belong to the second category of state (89,04%. Healthy plants are less than 8% from the total number of dominant species. The number of dead plants makes up 0,35%

  12. Changes in cause-specific mortality during heat waves in central Spain, 1975-2008

    Science.gov (United States)

    Miron, Isidro Juan; Linares, Cristina; Montero, Juan Carlos; Criado-Alvarez, Juan Jose; Díaz, Julio

    2015-09-01

    The relationship between heat waves and mortality has been widely described, but there are few studies using long daily data on specific-cause mortality. This study is undertaken in central Spain and analysing natural causes, circulatory and respiratory causes of mortality from 1975 to 2008. Time-series analysis was performed using ARIMA models, including data on specific-cause mortality and maximum and mean daily temperature and mean daily air pressure. The length of heat waves and their chronological number were analysed. Data were stratified in three decadal stages: 1975-1985, 1986-1996 and 1997-2008. Heat-related mortality was triggered by a threshold temperature of 37 °C. For each degree that the daily maximum temperature exceeded 37 °C, the percentage increase in mortality due to circulatory causes was 19.3 % (17.3-21.3) in 1975-1985, 30.3 % (28.3-32.3) in 1986-1996 and 7.3 % (6.2-8.4) in 1997-2008. The increase in respiratory cause ranged from 12.4 % (7.8-17.0) in the first period, to 16.3 % (14.1-18.4) in the second and 13.7 % (11.5-15.9) in the last. Each day of heat-wave duration explained 5.3 % (2.6-8.0) increase in respiratory mortality in the first period and 2.3 % (1.6-3.0) in the last. Decadal scale differences exist for specific-causes mortality induced by extreme heat. The impact on heat-related mortality by natural and circulatory causes increases between the first and the second period and falls significantly in the last. For respiratory causes, the increase is no reduced in the last period. These results are of particular importance for the estimation of future impacts of climate change on health.

  13. 78 FR 55117 - Ultimate Heat Sink for Nuclear Power Plants; Draft Regulatory Guide

    Science.gov (United States)

    2013-09-09

    ... COMMISSION Ultimate Heat Sink for Nuclear Power Plants; Draft Regulatory Guide AGENCY: Nuclear Regulatory... Nuclear Power Plants.'' This regulatory guide (RG) describes methods and procedures acceptable to the NRC staff that nuclear power plant facility licensees and applicants may use to implement general...

  14. Central Data Processing System (CDPS) user's manual: Solar heating and cooling program

    Science.gov (United States)

    1976-01-01

    The software and data base management system required to assess the performance of solar heating and cooling systems installed at multiple sites is presented. The instrumentation data associated with these systems is collected, processed, and presented in a form which supported continuity of performance evaluation across all applications. The CDPS consisted of three major elements: communication interface computer, central data processing computer, and performance evaluation data base. Users of the performance data base were identified, and procedures for operation, and guidelines for software maintenance were outlined. The manual also defined the output capabilities of the CDPS in support of external users of the system.

  15. Analysis of temporal variability and spatial characteristics of heat waves in central Europe using extremity index

    Czech Academy of Sciences Publication Activity Database

    Lhotka, Ondřej; Kyselý, Jan

    Brno : Global change research centre, Academy of Sciences of the Czech Republic, v. v. i, 2013 - (Stojanov, R.; Žalud, Z.; Cudlín, P.; Farda, A.; Urban, O.; Trnka, M.), s. 105-109 ISBN 978-80-904351-8-6. [Global Change and Resilience . Brno (CZ), 22.05.2013-24.05.2013] R&D Projects: GA ČR GAP209/10/2265; GA MŠk 7AMB12AR005 Institutional support: RVO:68378289 Keywords : heat waves * central Europe * extremity index Subject RIV: DG - Athmosphere Sciences, Meteorology

  16. The central role of heat shock factor 1 in synaptic fidelity and memory consolidation.

    Science.gov (United States)

    Hooper, Philip L; Durham, Heather D; Török, Zsolt; Hooper, Paul L; Crul, Tim; Vígh, László

    2016-09-01

    Networks of neuronal synapses are the fundamental basis for making and retaining memory. Reduced synapse number and quality correlates with loss of memory in dementia. Heat shock factor 1 (HSF1), the major transcription factor regulating expression of heat shock genes, plays a central role in proteostasis, in establishing and sustaining synaptic fidelity and function, and in memory consolidation. Support for this thesis is based on these observations: (1) heat shock induces improvements in synapse integrity and memory consolidation; (2) synaptic depolarization activates HSF1; (3) activation of HSF1 alone (independent of the canonical heat shock response) augments formation of essential synaptic elements-neuroligands, vesicle transport, synaptic scaffolding proteins, lipid rafts, synaptic spines, and axodendritic synapses; (4) HSF1 coalesces and activates memory receptors in the post-synaptic dendritic spine; (5) huntingtin or α-synuclein accumulation lowers HSF1 while HSF1 lowers huntingtin and α-synuclein aggregation-a potential vicious cycle; and (6) HSF1 agonists (including physical activity) can improve cognitive function in dementia models. Thus, via direct gene expression of synaptic elements, production of HSPs that assure high protein fidelity, and activation of other neuroprotective signaling pathways, HSF1 agonists could provide breakthrough therapy for dementia-associated disease. PMID:27283588

  17. Mapping regional distribution of land surface heat fluxes on the southern side of the central Himalayas using TESEBS

    Science.gov (United States)

    Amatya, Pukar Man; Ma, Yaoming; Han, Cunbo; Wang, Binbin; Devkota, Lochan Prasad

    2016-05-01

    Recent scientific studies based on large-scale climate model have highlighted the importance of the heat release from the southern side of the Himalayas for the development of South Asian Summer Monsoon. However, studies related to land surface heat fluxes are nonexistent on the southern side. In this study, we test the feasibility of deriving land surface heat fluxes on the central Himalayan region using Topographically Enhanced Surface Energy Balance System (TESEBS), which is forced by MODIS land surface products and Global Land Data Assimilation System (GLDAS) meteorological data. The model results were validated using the first eddy covariance measurement system established in the southern side of the central Himalayas. The derived land surface heat fluxes were close to the field measurements with mean bias of 15.97, -19.89, 8.79, and -20.39 W m-2 for net radiation flux, ground heat flux, sensible heat flux, and latent heat flux respectively. Land surface heat fluxes show strong contrast in pre monsoon, summer monsoon, post monsoon, and winter seasons and different land surface states among the different physiographic regions. In the central Himalayas, the latent heat flux is the dominant consumer of available energy for all physiographic regions except for the High Himalaya where the sensible heat flux is high.

  18. Central European botanic gardens as centres of dispersal of alien plants

    Directory of Open Access Journals (Sweden)

    Halina Galera

    2011-04-01

    Full Text Available The aim of the work was to estimate the specific role that Central European botanic gardens play in the dispersal of alien plants, which results from the wide variety of plants cultivated in the gardens and regular international exchange of plant material between these institutions. We compared the results of recent field studies (in eight Polish botanic gardens and a review of older literature data and herbarium collections (from Central European botanic gardens. We found that in Poland the proportion of botanic garden escapes was lower (3% than would be expected from the "tens rule". Botanic gardens have played a considerable role in the development of the synanthropic flora of Central Europe in the last 200 years. We determined a group of species introduced through a network of botanic gardens and propose 5 theoretical patterns to describe the mode and pathways of the early stages of introduction of these species.

  19. Preliminary design of the Carrisa Plains solar central receiver power plant. Volume II. Plant specifications

    Energy Technology Data Exchange (ETDEWEB)

    Price, R. E.

    1983-12-31

    The specifications and design criteria for all plant systems and subsystems used in developing the preliminary design of Carrisa Plains 30-MWe Solar Plant are contained in this volume. The specifications have been organized according to plant systems and levels. The levels are arranged in tiers. Starting at the top tier and proceeding down, the specification levels are the plant, system, subsystem, components, and fabrication. A tab number, listed in the index, has been assigned each document to facilitate document location.

  20. Medicinal Plants from Mexico, Central America, and the Caribbean Used as Immunostimulants

    Science.gov (United States)

    Juárez-Vázquez, María del Carmen; Campos-Xolalpa, Nimsi

    2016-01-01

    A literature review was undertaken by analyzing distinguished books, undergraduate and postgraduate theses, and peer-reviewed scientific articles and by consulting worldwide accepted scientific databases, such as SCOPUS, Web of Science, SCIELO, Medline, and Google Scholar. Medicinal plants used as immunostimulants were classified into two categories: (1) plants with pharmacological studies and (2) plants without pharmacological research. Medicinal plants with pharmacological studies of their immunostimulatory properties were subclassified into four groups as follows: (a) plant extracts evaluated for in vitro effects, (b) plant extracts with documented in vivo effects, (c) active compounds tested on in vitro studies, and (d) active compounds assayed in animal models. Pharmacological studies have been conducted on 29 of the plants, including extracts and compounds, whereas 75 plants lack pharmacological studies regarding their immunostimulatory activity. Medicinal plants were experimentally studied in vitro (19 plants) and in vivo (8 plants). A total of 12 compounds isolated from medicinal plants used as immunostimulants have been tested using in vitro (11 compounds) and in vivo (2 compounds) assays. This review clearly indicates the need to perform scientific studies with medicinal flora from Mexico, Central America, and the Caribbean, to obtain new immunostimulatory agents. PMID:27042188

  1. Medicinal Plants from Mexico, Central America, and the Caribbean Used as Immunostimulants.

    Science.gov (United States)

    Alonso-Castro, Angel Josabad; Juárez-Vázquez, María Del Carmen; Campos-Xolalpa, Nimsi

    2016-01-01

    A literature review was undertaken by analyzing distinguished books, undergraduate and postgraduate theses, and peer-reviewed scientific articles and by consulting worldwide accepted scientific databases, such as SCOPUS, Web of Science, SCIELO, Medline, and Google Scholar. Medicinal plants used as immunostimulants were classified into two categories: (1) plants with pharmacological studies and (2) plants without pharmacological research. Medicinal plants with pharmacological studies of their immunostimulatory properties were subclassified into four groups as follows: (a) plant extracts evaluated for in vitro effects, (b) plant extracts with documented in vivo effects, (c) active compounds tested on in vitro studies, and (d) active compounds assayed in animal models. Pharmacological studies have been conducted on 29 of the plants, including extracts and compounds, whereas 75 plants lack pharmacological studies regarding their immunostimulatory activity. Medicinal plants were experimentally studied in vitro (19 plants) and in vivo (8 plants). A total of 12 compounds isolated from medicinal plants used as immunostimulants have been tested using in vitro (11 compounds) and in vivo (2 compounds) assays. This review clearly indicates the need to perform scientific studies with medicinal flora from Mexico, Central America, and the Caribbean, to obtain new immunostimulatory agents. PMID:27042188

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

    International Nuclear Information System (INIS)

    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

  3. District heating system of Belgrade supplied from the co-generation plant 'Obrenovac' (Yugoslavia)

    International Nuclear Information System (INIS)

    The paper presents most relevant technical and economic features of the Project called 'System for supplying Belgrade with heat' (SDGB) from the thermal power plant 'Obrenovac', based on domestic coal and reconstruction of condensing power plant for combined generation of electricity and heat for the needs of municipal energy consumption. The system is designed for transport thermal energy, with capacity of 730 MJ/s from the Thermal Power Plant 'Nikola Tesla' / A to the existing heat plant 'Novi Beograd' based on the natural gas. The paper also gives the comparison of most important technical and economic features of 'SDGB' Project with the similar Project of District Heating System for supplying Prague with the thermal energy from Thermal Power Plant Melnik. (Author)

  4. Thermal, performance and economic analysis of solar thermal central receiver power plants

    International Nuclear Information System (INIS)

    This paper presents the results of modeling the thermal performance and economic feasibility of large (utility scale) and small solar thermal central receiver power plants. Five options have been studied: molten nitrate salt external central receiver (CR) with molten salt storage, molten nitrate salt cavity CR with salt storage, sodium external CR with sodium storage, sodium external CR with salt storage, water/steam external CR with oil/rock storage. Each option is analyzed over a range of plant power ratings from 1 MWe to 100 MWe and over a range of capacity factors. 12 figs., 4 tabs., 6 refs

  5. Uranium accumulation by aquatic plants from uranium-contaminated water in Central Portugal.

    Science.gov (United States)

    Pratas, João; Favas, Paulo J C; Paulo, Carlos; Rodrigues, Nelson; Prasad, M N V

    2012-03-01

    Several species of plants have developed a tolerance to metal that enables them to survive in metal contaminated and polluted sites. Some of these aquatic plants have been reported to accumulate significant amounts of specific trace elements and are, therefore, useful for phytofiltration. This work focuses the potential of aquatic plants for the phytofiltration of uranium (U) from contaminated water. We observed that Callitriche stagnalis, Lemna minor, and Fontinalis antipyretica, which grow in the uraniferous geochemical province of Central Portugal, have been able to accumulate significant amounts of U. The highest concentration of U was found in Callitriche stagnalis (1948.41 mg/kg DW), Fontinalis antipyretica (234.79 mg/kg DW), and Lemna minor (52.98 mg/kg DW). These results indicate their potential for the phytofiltration of U through constructed treatment wetlands or by introducing these plants into natural water bodies in the uraniferous province of Central Portugal. PMID:22567707

  6. Effects of Ascorbic Acid Application in Strawberry Plants During Heat Stress

    OpenAIRE

    Sergul ERGIN; AYDOGAN, Cigdem; OZTURK, Nilufer; Turhan, Ece

    2014-01-01

    Frigo seedlings of ‘Redlands Hope’ (R. Hope) and ‘Festival’ strawberry cultivars, which are heat-tolerant and heat-sensitive, respectively were grown in a controlled greenhouse. When the seedlings had 5-6 leaves (11 weeks old); half of the plants were sprayed with 3 mM ascorbic acid (AA) every three days for 3 weeks (7 applications) in order to investigate whether AA is effective on heat stress tolerance of the cultivars, the other half ones were used as control plants. Plants were then trans...

  7. Oil condition effects over the heat transfer performance in CSP parabolic trough power plants

    OpenAIRE

    Montero Pascual, Daniel

    2015-01-01

    The present master thesis is devoted to the analysis of the energy flow in a concentrated solar power plant with regards of the heat transfer fluid. In this work it is analysed the heat transfer capacity of the synthetic oil commonly used in parabolic trough power plants after a few years in operation, aiming to find heat transfer problems due to fouling resistance both in the collector field and in the heat exchangers. In order to evaluate the presented problematic it is introduced a para...

  8. Review of shell-and-tube heat exchanger fouling and corrosion in geothermal power plant service

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, P.F. II

    1983-12-01

    Heat exchangers for hot geofluid/working substance vaporizers for binary power plants are considered. A brief description of the physical test apparatus and the geofluid chemistry for each of the several heat exchanger tests is presented. The fouling data developed from these tests are summarized, in most cases presenting a mathematical expression for the increase in fouling factor with time. The materials performance data developed from these same tests are explored. The performance of shell-and-tube heat exchangers used as condensers and ancillary coolers in the power plant heat rejection system is considered.

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

    International Nuclear Information System (INIS)

    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/mi2 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)

  10. Economic and environmental efficiencey of district heating plants

    International Nuclear Information System (INIS)

    District heating, the conversion of primary energy into distributed thermal energy and possible electric energy, is a challenge to regulate. In addition to the ever present asymmetric information in any sufficiently complex activity, some of the inputs for district heating, such as excess process heat, have arbitrary valuation. This study concerns the most developed European district heating and cogeneration system, the Danish. By assessing environmental and economic efficiency, the impact of governmental, market and managerial imperfections are estimated. The principal methodological base is the additive Data Envelopment Analysis model with extensions. The paper ends with some policy suggestions

  11. Economic and environmental efficiency of district heating plants

    International Nuclear Information System (INIS)

    District heating, the conversion of primary energy into distributed thermal energy and possible electric energy, is a challenge to regulate. In addition to the ever present asymmetric information in any sufficiently complex activity, some of the inputs for district heating, such as excess process heat, have arbitrary valuation. This study concerns th emost developed European district heating and cogeneration systen, The Danish. By assessing environmental and economic efficiency, The impact of governmental, market and managerial imperfection are estimated. The principal methodological base is the additive data envelopment analysis model with extensions. The paper ends with some policy suggestions. (au)

  12. Floating nuclear heat. And power station 'Pevec' with KLT-40S type reactor plant for remote regions of Russia

    International Nuclear Information System (INIS)

    Floating small nuclear power plants power for local energy systems of littoral regions of Russia, located far from central energy system, open a new line in nuclear power development. Designing a floating power unit of a lead nuclear heat and power generating station for port Pevec at the Chuckchee national district is currently nearing completion. Most labor-intensive components are being manufactured. The co-generation NPP Pevec is to be created on the basis of a floating power unit with KLT-40S type reactor plant. KLT-40S reactor plant is based on similar propulsion plants, verified at operation of Russia's nuclear-powered civil ships, evolutionary improved by elimination of 'weak points' revealed during its prototypes operation or on the basis of safety analysis. KLT-40S reactor plant uses the most wide-spread and developed in the world practice PWR-type reactor. KLT-40S meets contemporary national and international requirements imposed to future reactor plants. The NHPS description, its main technical-economic data, environmental safety indices, basic characteristics of KLT-40S reactor plant are presented. Prospects of small NPPs utilization outside Russia, particularly as an energy source for sea water desalination, are considered. (author)

  13. Technical and economical analysis of concepts for using the heat of biogas plants in rural areas

    International Nuclear Information System (INIS)

    Since the implementation of the EEG in Germany the biogas production becomes an independent branch of industry in the agriculture. At this time more than 90 percent of the biogas plants work with co-generation plant for heat and power with a thermal engine efficiencies of more than 50 percent. Because of the location in the rural area heat costumers with a continuous demand of heat over the whole year are rare. This research had a closer look how to use the heat of biogas production efficiently and also generating profit. The aim of the study was to use heat over the whole year, a profitable heat concept without counting the KWK-bonus and an added value on the farm. During the study the following concepts were analyzed: asparagus production using soil heating, drying equipment for different products, the production of fish in aquaculture, the poultry production and the heated production of tomatoes. The results showed different concepts using heat of biogas plants as efficient for farmers. However with only one concept the aims - to use the heat over the whole year, generating a profitable heat concept without counting the KWK-bonus, add an value on the farm - mostly can not be achieved. The combination of different heat concepts is necessary. In this analysis the poultry production in combination with the dryer can be considered as the most efficient concept. Bearing in mind the benefit which can be generated with a heat concept as well as the higher income and the higher technical efficiency of biogas plants operators should implement an individual concept for their heat.

  14. Heat supply from municipal solid waste incineration plants in Japan: Current situation and future challenges.

    Science.gov (United States)

    Tabata, Tomohiro; Tsai, Peii

    2016-02-01

    The use of waste-to-energy technology as part of a municipal solid waste management strategy could reduce the use of fossil fuels and contribute to prevention of global warming. In this study, we examined current heat and electricity production by incineration plants in Japan for external use. Herein, we discuss specific challenges to the promotion of heat utilisation and future municipal solid waste management strategies. We conducted a questionnaire survey to determine the actual conditions of heat production by incineration plants. From the survey results, information of about 498 incineration plants was extracted. When we investigated the relationship between heat production for external use and population density where incineration plants were located, we found that regions with a population density energy for factories, markets, and related use, was noted in cities with a population density of 2000 to 4000 persons (km(2))(-1). Several incineration plants have poor performance for heat production because there are few facilities near them to provide demand for the energy. This is the result of redundant capacity, and is reflected in the heat production performance. Given these results, we discussed future challenges to creating energy demand around incineration plants where there is presently none. We also examined the challenges involved in increasing heat supply beyond the present situation. PMID:26628053

  15. Plant hydraulics as a central hub integrating plant and ecosystem function: meeting report for 'Emerging Frontiers in Plant Hydraulics' (Washington, DC, May 2015).

    Science.gov (United States)

    Sack, Lawren; Ball, Marilyn C; Brodersen, Craig; Davis, Stephen D; Des Marais, David L; Donovan, Lisa A; Givnish, Thomas J; Hacke, Uwe G; Huxman, Travis; Jansen, Steven; Jacobsen, Anna L; Johnson, Daniel M; Koch, George W; Maurel, Christophe; McCulloh, Katherine A; McDowell, Nate G; McElrone, Andrew; Meinzer, Frederick C; Melcher, Peter J; North, Gretchen; Pellegrini, Matteo; Pockman, William T; Pratt, R Brandon; Sala, Anna; Santiago, Louis S; Savage, Jessica A; Scoffoni, Christine; Sevanto, Sanna; Sperry, John; Tyerman, Stephen D; Way, Danielle; Holbrook, N Michele

    2016-09-01

    Water plays a central role in plant biology and the efficiency of water transport throughout the plant affects both photosynthetic rate and growth, an influence that scales up deterministically to the productivity of terrestrial ecosystems. Moreover, hydraulic traits mediate the ways in which plants interact with their abiotic and biotic environment. At landscape to global scale, plant hydraulic traits are important in describing the function of ecological communities and ecosystems. Plant hydraulics is increasingly recognized as a central hub within a network by which plant biology is connected to palaeobiology, agronomy, climatology, forestry, community and ecosystem ecology and earth-system science. Such grand challenges as anticipating and mitigating the impacts of climate change, and improving the security and sustainability of our food supply rely on our fundamental knowledge of how water behaves in the cells, tissues, organs, bodies and diverse communities of plants. A workshop, 'Emerging Frontiers in Plant Hydraulics' supported by the National Science Foundation, was held in Washington DC, 2015 to promote open discussion of new ideas, controversies regarding measurements and analyses, and especially, the potential for expansion of up-scaled and down-scaled inter-disciplinary research, and the strengthening of connections between plant hydraulic research, allied fields and global modelling efforts. PMID:27037757

  16. Economic and environmental efficiency of district heating plants

    DEFF Research Database (Denmark)

    Agrell, Per J.; Bogetoft, Peter

    2005-01-01

    heat, have arbitrary valuation.This study concerns the most developed European district heating and cogeneration system, the Danish.By assessing environmental and economic ef¿ciency, the impact of governmental, market and managerial imperfections are estimated.The principal methodological base is the...

  17. Two-phase distribution in the vertical flow line of a domestic wet central heating system

    Directory of Open Access Journals (Sweden)

    Ge Y.T.

    2013-04-01

    Full Text Available The theoretical and experimental aspects of bubble distribution in bubbly two-phase flow are reviewed in the context of the micro bubbles present in a domestic gas fired wet central heating system. The latter systems are mostly operated through the circulation of heated standard tap water through a closed loop circuit which often results in water supersaturated with dissolved air. This leads to micro bubble nucleation at the primary heat exchanger wall, followed by detachment along the flow. Consequently, a bubbly two-phase flow characterises the flow line of such systems. The two-phase distribution across the vertical and horizontal pipes was measured through a consideration of the volumetric void fraction, quantified through photographic techniques. The bubble distribution in the vertical pipe in down flow conditions was measured to be quasi homogenous across the pipe section with a negligible reduction in the void fraction at close proximity to the pipe wall. Such a reduction was more evident at lower bulk fluid velocities.

  18. Recovery of heat from the refrigeration plant at the Bjoerkaeng stadium in Huddinge

    Energy Technology Data Exchange (ETDEWEB)

    Glas, L.O.

    1984-01-01

    The report describes an investigation of heat recovery from the refrigeration plant at the ice hockey rinks outdoors and in the stadium building at the Bjoerkaeng athletics centre. Heat emitted by the refrigeration plant is utilized for heating of the stadium building and for heating water. The heat recovery was measured and analysed over the period 1.12.78-30.11.79, a net energy saving of approximately 380,000 kWh being achieved. The heat recovery analysis comprises a complete heat balance for the ice hockey rinks, the ice stadium, the water heating and the refrigeration plant. On average, test results are very near the figures produced by calculations. The calculation method described should therfore reproduce with good accuracy the possible energy savings in refrigeration plants for ice rinks both indoors and outdoors, of widely differing sizes and geographical location. For instance, the calculation takes into account the effect of the ice stadium temperature selected on the net energy saving and the recoverable quantity of heat.

  19. Project No. 6 - Replacement of the heating and steam plant

    International Nuclear Information System (INIS)

    At present the Ignalina NPP facilities and Visaginas town are supplied with heat and steam from the district heating facility at Ignalina NPP. A back-up system, dating from 1979, supplies heat and steam when the district heating system is under repair or in case of outages of units 1 and 2. The existing back-up system does no longer meet with applicable technical and safety standards. A breakdown of the back-up system might result in the interruption of the supply to Ignalina NPP of heat and steam necessary for a number of processes, including waste management. Reconstruction of the existing boiler houses is not economically viable option, nor recommendable, for safety reasons, as it would mean the temporary closing of the back-up system. Project activities includes the design, construction and commissioning of the proposed facility, including all licensing documentation

  20. The Impact of Implementation of Total quality Management on Plants' Productivity: Evidence from Poultry Processing Plants- Saudi Arabia- Central Region

    Directory of Open Access Journals (Sweden)

    ELHAJ ABDELMOULA.ELSIDDIG MUSA,

    2011-05-01

    Full Text Available Productivity index as an important business determinant factor for profitability and business performance has been studied in this research versus TQM varibles. The study highlighted out the impacts ofimplementation of TQM on productivity in poultry processing plants in Saudi Arabia – Central Region. The significance of this research represented in exploring the impact of TQM practices on Poultry Processing Plants' productivity. Seven determinants of TQM practices and their impacts were measured against productivity. The determinants included top management commitment, customer focus, rewards & training, continual improvement, cooperation & teamwork, prevention focus and measurement system. Data was collected by using Questionnaire tool. The Questionnaire is of closed ended questions. It consists of three parts, the first part is demographic information about the study sample, the second part about implementation of the total quality management and the third part is to measure productivity. A sample of three poultry processing plants that effectively implemented total quality management were purposively chosen out of eight plants in Saudi Arabia Central Region. The study respondents are purposively chosen which consists quality team, production supervisors, Total quality management and production managers. 73 respondents out 75 participated in the survey. The finding indicated that the TQM practices have positive impact on poultry processing plants' productivity.

  1. Ultimate heat sink and directly associated heat transport systems for nuclear power plants

    International Nuclear Information System (INIS)

    The scope of the Guide covers design considerations for various types of ultimate heat sinks (UHS) and directly associated heat transport systems, and for types and sources of related heat transport fluids. The scope encompasses the conditions for using the UHS for reactor safety following postulated initiating events, as well as its selection, sizing and reliability

  2. 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.

  3. Wood pellet heating plants. Market survey. 4. upd. ed.; Hackschnitzel-Heizung. Marktuebersicht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-15

    Wood pellets from the agriculture and forestry offer an enormous potential for the development of the use of bio energy in the private area as well as in industry and commerce. Within the market survey 'Wood pellet heating systems', the Fachagentur Nachwachsende Rohstoffe e.V. (Guelzow-Pruezen, Federal Republic of Germany) reported on the targets and measures of the Federal Government with respect to the heating with biomass, wood pellets as solid biofuels (standardization of solid biofuels, supply, features, evaluation), wood pellet heating plants, economic considerations, market survey on wood pellet heating plants as well as list of addresses for producers of wood pellet heating plants and suppliers of wood pellets.

  4. Thermodynamic analysis of an existing coal-fired power plant for district heating/cooling application

    International Nuclear Information System (INIS)

    In a conventional coal-fired power plant, which is only designed for electricity generation, 2/3 of fuel energy is wasted through stack gases and cooling water of condensers. This waste energy could be recovered by trigeneration; modifying the plants in order to meet district heating/cooling demand of their locations. In this paper, thermodynamical analysis of trigeneration conversion of a public coal-fired power plant, which is designed only for electricity generation, has been carried out. Waste heat potentials and other heat extraction capabilities have been evaluated. Best effective steam extraction point for district heating/cooling system; have been identified by conducting energetic and exergetic performance analyses. Analyses results revealed that the low-pressure turbine inlet stage is the most convenient point for steam extraction for the plant analyzed.

  5. Thermodynamic analysis of an existing coal-fired power plant for district heating/cooling application

    Energy Technology Data Exchange (ETDEWEB)

    Erdem, H.H.; Dagdas, A.; Sevilgen, S.H.; Cetin, B.; Akkaya, A.V.; Sahin, B.; Teke, I.; Gungor, C.; Atas, S. [Yildiz Technical University, Istanbul (Turkey). Dept. of Mechanical Engineering

    2010-02-15

    In a conventional coal-fired power plant, which is only designed for electricity generation, 2/3 of fuel energy is wasted through stack gases and cooling water of condensers. This waste energy could be recovered by trigeneration; modifying the plants in order to meet district heating/cooling demand of the locations. In this paper, thermodynamical analysis of trigeneration conversion of a public coal-fired power plant, which is designed only for electricity generation, has been carried out. Waste heat potential and other heat extraction capabilities have been evaluated. Best effective steam extraction point for district heating/cooling systems have been identified by conducting energetic and exergetic performance analyses. Analyses results revealed that the low-pressure turbine inlet stage is the most convenient point for steam extraction for the plant analyzed.

  6. Design optimization of a polygeneration plant producing power, heat, and lignocellulosic ethanol

    DEFF Research Database (Denmark)

    Lythcke-Jørgensen, Christoffer Ernst; Haglind, Fredrik

    2015-01-01

    ethanol production capacity, ranging from 0.746 for 5 kg/s to 0.696 for 12 kg/s. This trend results from operating constraints that induce expensive operation patterns in periods of high district heating loads or shut-down periods for the combined heat and power plant. A sensitivity analysis indicates......A promising way to increase the energy efficiency and reduce costs of biofuel production is to integrate it with heat and power production in polygeneration plants. This study treats the retrofitting of a Danish combined heat and power plant by integrating lignocellulosic ethanol production based...... on wheat straw with the aim of minimizing specific ethanol production cost. Previously developed and validated models of the facilities are applied in the attempt to solve the design optimization problem. Straw processing capacities in the range of 5–12 kg/s are considered, while plant operation is...

  7. Role and Regulation of Autophagy in Heat Stress Responses of Tomato Plants

    Directory of Open Access Journals (Sweden)

    Jie eZhou

    2014-04-01

    Full Text Available As sessile organisms, plants are constantly exposed to a wide spectrum of stress conditions such as high temperature, which causes protein misfolding. Misfolded proteins are highly toxic and must be efficiently removed to reduce cellular proteotoxic stress if restoration of native conformations is unsuccessful. Although selective autophagy is known to function in protein quality control by targeting degradation of misfolded and potentially toxic proteins, its role and regulation in heat stress responses have not been analyzed in crop plants. In the present study, we found that heat stress induced expression of autophagy-related (ATG genes and accumulation of autophagosomes in tomato plants. Virus-induced gene silencing of tomato ATG5 and ATG7 genes resulted in increased sensitivity of tomato plants to heat stress based on both increased development of heat stress symptoms and compromised photosynthetic parameters of heat-stressed leaf tissues. Silencing of tomato homologs for the selective autophagy receptor NBR1, which targets ubiquitinated protein aggregates, also compromised tomato heat tolerance. To better understand the regulation of heat-induced autophagy, we found that silencing of tomato ATG5, ATG7 or NBR1 compromised heat-induced expression of not only the targeted genes but also other autophagy-related genes. Furthermore, we identified two tomato genes encoding proteins highly homologous to Arabidopsis WRKY33 transcription factor, which has been previously shown to interact physically with an autophagy protein. Silencing of tomato WRKY33 genes compromised tomato heat tolerance and reduced heat-induced ATG gene expression and autophagosome accumulation. Based on these results, we propose that heat-induced autophagy in tomato is subject to cooperative regulation by both WRKY33 and ATG proteins and plays a critical role in tomato heat tolerance, mostly likely through selective removal of heat-induced protein aggregates.

  8. A centralized hazardous waste treatment plant: the facilities of the ZVSMM at Schwabach as an example

    Energy Technology Data Exchange (ETDEWEB)

    Amsoneit, Norbert [Zweckverband Sondermuell-Entsorgung Mittelfranken, Rednitzhembach (Germany)

    1993-12-31

    In this work a centralized hazardous waste treatment plant is described and its infra-structure is presented. Special emphasis is given to the handling of the residues produced and the different treatment processes at the final disposal. 2 refs., 4 figs.

  9. Sweet corn growth and yield responses to planting dates of the north central U.S.

    Science.gov (United States)

    Sweet corn is planted over a three-month period in the north central U.S. in order to extend availability for fresh market and processing; however, the extent to which development and growth of sweet corn changes during this period is unreported. Field experiments were conducted in 2006 and 2007 to...

  10. Spatial and temporal characteristics of heat waves over Central Europe in an ensemble of regional climate model simulations

    Science.gov (United States)

    Lhotka, Ondřej; Kyselý, Jan

    2015-11-01

    The study examines the capability of regional climate models (RCMs) to reproduce spatial and temporal characteristics of severe Central European heat waves. We analysed an ensemble of seven RCM simulations driven by the ERA-40 reanalysis over the 1961-2000 period, in comparison to observed data from the E-OBS gridded dataset. Heat waves were defined based on regionally significant excesses above the model-specific 95 % quantile of summer daily maximum air temperature distribution and their severity was described using the extremity index. The multi-model mean reflected the observed characteristics of heat waves quite well, but considerable differences were found among the individual RCMs. The RCMs had a tendency to simulate too many heat waves that were shorter but their temperature peak was more pronounced on average compared to E-OBS. Deficiencies were found also in reproducing interannual and interdecadal variability of heat waves. Using as an example the most severe Central European heat wave that occurred in 1994, we demonstrate that its magnitude was underestimated in all RCMs and that this bias was linked to overestimation of precipitation during and before the heat wave. By contrast, a simulated precipitation deficit during summer 1967 in the majority of RCMs contributed to an "erroneous" heat wave. This shows that land-atmosphere coupling is crucial for developing severe heat waves and its proper reproduction in climate models is essential for obtaining credible scenarios of future heat waves.

  11. Natural heat transfer augmentation in passive advanced BWR plants

    International Nuclear Information System (INIS)

    In the European Simplified Boiling Water Reactor (ESBWR), the long-term post-accident containment pressure is determined by the combination of non condensable gas pressure and steam pressure in the wet well gas space. Since there are no active systems for heat removal in the wet well, energy transmitted to the wet well gas space, by a variety of means, must be removed by passive heat transfer to the walls and suppression pool (SP). The cold suppression pool located below the hotter gas space provides a stable configuration in which convection currents are suppressed thus limiting heat and mass transfer between the gas space and pool. However, heat transfer to the walls results in natural circulation currents that can augment the heat and mass transfer to the pool surface. Using a simplified model, parametric studies are carried out to show that augmentation of the order of magnitude expected can significantly impact the heat and mass transfer to the pool. Additionally a review of available literature in the area of augmentation and mixed convection of this type is presented and indicates the need for additional experimental work in order to develop adequate models for heat and mass transfer augmentation in the configuration of a BWR suppression pool. (author)

  12. Application of solar energy in heating and cooling of residential buildings under Central Asian conditions

    Directory of Open Access Journals (Sweden)

    Usmonov Shukhrat Zaurovich

    2014-04-01

    Full Text Available Solar radiation is the main source of thermal energy for almost all the processes developing in the atmosphere, hydrosphere, and biosphere. The total duration of sunshine in Tajikistan ranges from 2100 to 3170 hours per year. Solar collectors can be mounted on the roof of a house after its renovation and modernization. One square meter of surface area in Central Asia accounts for up to 1600 kW/h of solar energy gain, whilst the average gain is 1200 kW/h. Active solar thermal systems are able to collect both low- and high-temperature heat. Active systems require the use of special engineering equipment for the collection, storage, conversion and distribution of heat, while a low-grade system is based on the principle of using a flat solar collector. The collector is connected to the storage tank for storing the heated water, gas, etc. The water temperature is in the range 50-60 °C. For summer air conditioning in hot climates, absorption-based solar installations with open evaporating solution are recommended. The UltraSolar PRO system offers an opportunity to make a home independent of traditional electricity. Combining Schneider Electric power generation and innovative energy storage technology results in an independent power supply. Traditional power supply systems can be short-lived since they store energy in lead-acid batteries which have a negligible lifetime. Lead-acid batteries operate in a constant charge-discharge mode, require specific conditions for best performance and can fail suddenly. Sudden failure of lead acid batteries, especially in winter in the northern part of Tajikistan, completely disables the heating system of a building. Instead, it is recommended to use industrial lithium-ion batteries, which have a significantly longer life and reliability compared to lead-acid type. UltraSolar PRO are ideal and provide a complete package, low noise and compact lithium-ion power supply.

  13. Integration of Solar Process Heat into an Existing Thermal Desalination Plant in Qatar

    OpenAIRE

    Dieckmann, Simon; Krishnamoorthy, Ganesh; Aboumadi, Mahmoud; Pandian, Yuvaraj; Dersch, Jürgen; Krüger, Dirk; Al-Rasheed, Abdulsattar; Krüger, Joachim; Ottenburger, Ulrich

    2015-01-01

    The water supply of many countries in the Middle East relies mainly on water desalination. In Qatar, the water network is completely fed with water from desalination plants. One of these power and desalination plants is located in Ras Abu Fontas, 20 km south of the capital Doha. The heat required for thermal desalination is provided by steam which is generated in waste heat recovery boilers (HRB) connected to gas turbines. Additionally, gas fired boilers or auxiliary firing in the HRBs are us...

  14. Renovating thermal power plant to trigeneration system for district heating/cooling: Evaluation of performance variation

    International Nuclear Information System (INIS)

    This paper presents performance assessments of thermal power plant-based co/tri-generation systems for district heating/cooling system. The power plants were originally designed exclusively for the generation of electricity. With respect to the renovation of power plants to co/tri-generation systems, the analysis of performance variations in the systems has been undertaken. For the purpose of simulation analysis, thermodynamic models of the eight thermal power plants have been developed. The performance variations have been evaluated with different performance criteria, including electrical power output, classical thermal efficiency, coefficient of performance and comprehensive thermal efficiency. The comprehensive thermal efficiency takes into account all products (electricity, heating and cooling energy) generated from the power plant-based tri-generation system. The results of analysis show that the comprehensive thermal efficiencies of the eight considered systems range from 49% to 61% in the heating mode, although their generated electrical power amounts decrease slightly. As a result, this type of modification for an existing power plant can greatly benefit the cause of energy efficiency and sustainable development. - Highlights: • Two new performance parameters are defined for renovated power plants. • The first parameter is named “The comprehensive thermal efficiency”. • The second parameter is named “coefficient of performance for heating/cooling”. • According to analysis all examined power plants can be converted to co-tri generation plant

  15. Case study: centralized wastewater treatment plant at Rawang Integrated Industrial Park

    International Nuclear Information System (INIS)

    Survey has been conducted at Rawang Integrated Industrial Park (RIIP) to investigate the possibility of setting up centralized industrial wastewater treatment plant. Rawang integrated industrial park is selected based on suggestion from department of environment. RIIP consists of about 150 industries with various type of activities operated in the area. Only 9 out of estimated 150 industries have individual wastewater treatment plant. The business activities of the 9 industries include food processing, textile, welding rods manufacturing, steel galvanizing and battery manufacturing. Wastewater generated by the industries are characterized by high oil and grease, cod, bod, organic matter, metal hydroxide and acidic. Besides that most of industries do the monitoring only once a month. This paper will also discuss the advantages of setting up of centralized industrial wastewater treatment plant to the government authorities, industries, people and environment. (Author)

  16. Implementing Geothermal Plants in the Copenhagen District Heating System

    DEFF Research Database (Denmark)

    Jensen, Louise Overvad; Hallgreen, Christine Erikstrup; Larsen, Esben

    2003-01-01

    The possibility of implementing geothermal heating in the Copenhagen district-heating system is assessed. This is done by building up general knowledge on the geological factors that influence the development of useable geothermal resources, factors concerning the exploration and utilization...... of geothermal energy in Denmark as well as the Danish potential, which, in former investigations, has been found to be around 100.000 PJ annually, and the economical potential is less, about 15 PJ/year. Since a considerable amount of the Danish power supply is tied to weather and the demand for heating......, an increasing demand for flexibility has been raised. Implementing geothermal heating would improve the flexibility in the Eastern Danish power system. Based on this information, as well as, on the hourly values of the expected production and consumption in 2010 and 2020, a model of the Copenhagen power...

  17. Performance improvement of a 330MWe power plant by flue gas heat recovery system

    Directory of Open Access Journals (Sweden)

    Xu Changchun

    2016-01-01

    Full Text Available In a utility boiler, the most heat loss is from the exhaust flue gas. In order to reduce the exhaust flue gas temperature and further boost the plant efficiency, an improved indirect flue gas heat recovery system and an additional economizer system are proposed. The waste heat of flue gas is used for high-pressure condensate regeneration heating. This reduces high pressure steam extraction from steam turbine and more power is generated. The waste heat recovery of flue gas decreases coal consumption. Other approaches for heat recovery of flue gas, direct utilization of flue gas energy and indirect flue gas heat recovery system, are also considered in this work. The proposed systems coupled with a reference 330MWe power plant are simulated using equivalent enthalpy drop method. The results show that the additional economizer scheme has the best performance. When the exhaust flue gas temperature decreases from 153℃ to 123℃, power output increases by 6.37MWe and increment in plant efficiency is about 1.89%. For the improved indirect flue gas heat recovery system, power output increases by 5.68MWe and the increment in plant efficiency is 1.69%.

  18. HEAT OF COMPRESSION AND OPPORTUNITY OF ITS USE FOR INCREASE OF EFFICIENCY OF AIR SEPARATION PLANTS

    OpenAIRE

    Лавренченко, Г. К.; Швец, С. Г.; Копытин, А. В.

    2015-01-01

    The analysis of possible directions useful utilization of heat of compression for production of the cold water in the heat-utilizing refrigerating machine and for organization heating vacuum regeneration of the adsorbent bloc of the desiccation and the purification of the air. Mark expediency of the application absorption lithium bromide refrigerating machines for organization preliminary cooling of the air in the air separation plant large productivity.

  19. Indigenous use and bio-efficacy of medicinal plants in the Rasuwa District, Central Nepal

    Directory of Open Access Journals (Sweden)

    Boon Emmanuel K

    2010-01-01

    Full Text Available Abstract Background By revealing historical and present plant use, ethnobotany contributes to drug discovery and socioeconomic development. Nepal is a natural storehouse of medicinal plants. Although several ethnobotanical studies were conducted in the country, many areas remain unexplored. Furthermore, few studies have compared indigenous plant use with reported phytochemical and pharmacological properties. Methods Ethnopharmacological data was collected in the Rasuwa district of Central Nepal by conducting interviews and focus group discussions with local people. The informant consensus factor (FIC was calculated in order to estimate use variability of medicinal plants. Bio-efficacy was assessed by comparing indigenous plant use with phytochemical and pharmacological properties determined from a review of the available literature. Criteria were used to identify high priority medicinal plant species. Results A total of 60 medicinal formulations from 56 plant species were documented. Medicinal plants were used to treat various diseases and disorders, with the highest number of species being used for gastro-intestinal problems, followed by fever and headache. Herbs were the primary source of medicinal plants (57% of the species, followed by trees (23%. The average FIC value for all ailment categories was 0.82, indicating a high level of informant agreement compared to similar studies conducted elsewhere. High FIC values were obtained for ophthalmological problems, tooth ache, kidney problems, and menstrual disorders, indicating that the species traditionally used to treat these ailments are worth searching for bioactive compounds: Astilbe rivularis, Berberis asiatica, Hippophae salicifolia, Juniperus recurva, and Swertia multicaulis. A 90% correspondence was found between local plant use and reported plant chemical composition and pharmacological properties for the 30 species for which information was available. Sixteen medicinal plants were

  20. Setting technical and economic features regarding nuclear heating plants implementation for heat supply in Romania by the year 2010

    International Nuclear Information System (INIS)

    This paper presents the world wide preoccupation concerning the implementation of nuclear heating plants for fulfilling the heat demand and the main technical data of the reactors destined to such NHP's. The second part of this paper shows technical and economic aspects related to the implementation of NHP's equipped with nuclear thermal reactor specialized in the exclusive heat supply in Romania at the level of the year 2010. Among these aspects the following are mentioned: - the results of researches and the world wide achievements; - the development and structure of the production and of the thermal electric energy as well as the feasibility for covering the demands for nuclear sources; - the impact on environment of various technologies for the production of thermal energy with conventional fuels comparing with NHP; - the philosophy from economic stand point for the covering part of the NHP heat demand. (authors)

  1. Internal combustion engine combined heat and power plants: Case study of the University of Perugia power plant

    International Nuclear Information System (INIS)

    A performance and economic analysis of an existing combined heat and power plant with an internal combustion engine and district heating for the Faculty of Engineering of the University of Perugia is presented. Results of the first 15 months of operation are shown and discussed with reference to daily performance of the combined heat and power plant, which shows how electric efficiency is only slightly affected by ambient temperature. A comparison of evaluation indexes for cogeneration plants is made with particular attention to the energy index (EI) which is used by Italian legislation as an evaluation parameter to decide if a combined heat and power plant can have access to financial benefits.A cost-benefits analysis based on the first year of operation was made to decide eventual changes in heat and power management, in order to reduce pay-back period and increase the internal rate of return of the investment. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  2. Use of ICRH for startup and initial heating of the TMX-U central cell

    International Nuclear Information System (INIS)

    Ion cyclotron resonance heating (ICRH) was evaluated and it was found to be satisfactory for use in establishing the conditions necessary to form a thermal barrier in TMX-upgrade (TMX-U). We discuss the constraints that must be satisfied in order to maintain a plasma, and outline a complete startup scenario that ends with the plasma at design parameters. The detailed discussions in this report concentrate on those parts of startup where ICRH is necessary. The ability of ICRH to couple power into a plasma at the fundamental ion cyclotron resonance, w/sub ci/, is determined from experiments with a half-turn loop antenna in the Phaedrus tandem mirror central cell. From these experiments, we get the empirical scaling that shows power deposited in the plasma is proportional to the plasma density

  3. Nuclear heating plants. Technical concepts and market potentials. Chapter 3

    International Nuclear Information System (INIS)

    Both the single-phase and the two-phase natural circulation cooling system has characteristic effects on the dynamic behavior of heating reactors. In two-phase systems, thermohydraulically conditioned flow oscillations can occur for certain pairs of values of inlet subcooling and thermal power, which, because of the feedback of the moderator density on the reactivity, lead to power oscillations. By means of a stability analysis the stability domains were identified for the operation of small and large heating reactors. In support of the computational model experiments were carried out on a heated test loop with natural circulation cooling. The analysis of the irregular load following behavior of heating reactors with natural circulation cooling takes up relatively much space. The HERE-300 and NHR-200 types are typical examples of single-phase and two-phase cooling, respectively. Contrary to common expectations the dynamic calculations prove that even the two-phase system shows a natural load following behavior under heating reactor conditions. (orig.)

  4. Heat supply measurement in industrial and municipal plants: Steam as heat source. Waermemengenmessung in Industrie- und kommunalen Anlagen: Dampf als Waermetraeger

    Energy Technology Data Exchange (ETDEWEB)

    Matthes, H.; Wiegand, W.

    1992-03-01

    Energy efficiency improvements and the thus to be furnished proof that energy is saved which is important in view of cost reductions and security of supply requires specialist and reliable solutions for consumption monitoring and distribution of heat for space heating and industrial processes.Heat supply measurements based on modern techniques i.e. flow measurement with vortex meter and microprocessor is presented in connection with the determination of differential enthalpy in plants using steam/condensate as heat source. Moreover heat sypply measurement is also the basis or evaluations of the communication between heat meters and heat control systems, e.g. in case of district heat supply. (orig./BWI).

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

    OpenAIRE

    Andreas Poullikkas

    2012-01-01

    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. ...

  6. PRACTICE ON EFFECTIVE ENERGY & HEAT UTILIZATION AT STEEL PLANT.

    Directory of Open Access Journals (Sweden)

    M.S. DHANDE,

    2010-11-01

    Full Text Available Now a days importance of steel plant go on increase and at the same time competition very treamoundouly raise. So the quality of steel and energy saving factors, very effectively work out today. What are the good strength and opportunity available in our industry that collect at the same weakness reducer and eliminate threats through the steel plant. Target to increase the production rate in plant. Quality of Steel improves so that life capacity of building work as use to these plant for maintain the sophisticated work. The work should be progressive but in future get the more scope because durability and life power must be increase the steel. From the data collection and analysis it is clear that plant required some modification because start melting shop I is also production rate than steel melting shop II but there is again some losses is to be available and that reducers is steel melting shop III for any plant start melting shop is the main heart for increase the efficienancy point of view.

  7. Colloid volume loading does not mitigate decreases in central blood volume during simulated hemorrhage while heat stressed

    DEFF Research Database (Denmark)

    Crandall, Craig G; Wilson, Thad E; Marving, Jens;

    2012-01-01

    attenuates the reduction in regional blood volumes during a simulated hemorrhagic challenge imposed via lower-body negative pressure (LBNP). Seven subjects underwent 30 mmHg LBNP while normothermic, during passive heat stress (increased internal temperature ~1°C), and while continuing to be heated after......±3%; spleen: 72±5%, all P0.05 relative to heat stress alone). These data suggest that blood volume loading during passive heat stress (via 11 ml/kg of a colloid solution) normalizes regional blood volumes in the torso, but does not mitigate the reduction in central blood volume during a simulated hemorrhagic......Heat stress results in profound reductions in the capacity to withstand a simulated hemorrhagic challenge; however, this capacity is normalized if the individual is volume loaded prior to the challenge. The present study tested the hypothesis that volume loading during passive heat stress...

  8. How a retrotransposon exploits the plant's heat stress response for its activation.

    Directory of Open Access Journals (Sweden)

    Vladimir V Cavrak

    2014-01-01

    Full Text Available Retrotransposons are major components of plant and animal genomes. They amplify by reverse transcription and reintegration into the host genome but their activity is usually epigenetically silenced. In plants, genomic copies of retrotransposons are typically associated with repressive chromatin modifications installed and maintained by RNA-directed DNA methylation. To escape this tight control, retrotransposons employ various strategies to avoid epigenetic silencing. Here we describe the mechanism developed by ONSEN, an LTR-copia type retrotransposon in Arabidopsis thaliana. ONSEN has acquired a heat-responsive element recognized by plant-derived heat stress defense factors, resulting in transcription and production of full length extrachromosomal DNA under elevated temperatures. Further, the ONSEN promoter is free of CG and CHG sites, and the reduction of DNA methylation at the CHH sites is not sufficient to activate the element. Since dividing cells have a more pronounced heat response, the extrachromosomal ONSEN DNA, capable of reintegrating into the genome, accumulates preferentially in the meristematic tissue of the shoot. The recruitment of a major plant heat shock transcription factor in periods of heat stress exploits the plant's heat stress response to achieve the transposon's activation, making it impossible for the host to respond appropriately to stress without losing control over the invader.

  9. Design Option of Heat Exchanger for the Next Generation Nuclear Plant

    Energy Technology Data Exchange (ETDEWEB)

    Eung Soo Kim; Chang Oh

    2008-09-01

    The Next Generation Nuclear Plant (NGNP), a very High temperature Gas-Cooled Reactor (VHTGRS) concept, will provide the first demonstration of a closed-loop Brayton cycle at a commercial scale of a few hundred megawatts electric and hydrogen production. The power conversion system (PCS) for the NGNP will take advantage of the significantly higher reactor outlet temperatures of the VHTGRS to provide higher efficiencies than can be achieved in the current generation of light water reactors. Besides demonstrating a system design that can be used directly for subsequent commercial deployment, the NGNP will demonstrate key technology elements that can be used in subsequent advanced power conversion systems for other Generation IV reactors. In anticipation of the design, development and procurement of an advanced power conversion system for the NGNP, the system integration of the NGNP and hydrogen plant was initiated to identify the important design and technology options that must be considered in evaluating the performance of the proposed NGNP. As part of the system integration of the VHTGRS and hydrogen production plant, the intermediate heat exchanger is used to transfer the process heat from VHTGRS to hydrogen plant. Therefore, the design and configuration of the intermediate heat exchanger are very important. This paper will include analysis of one stage versus two stage heat exchanger design configurations and thermal stress analyses of a printed circuit heat exchanger, helical coil heat exchanger, and shell/tube heat exchanger.

  10. Uses of titanium in heat exchangers for condensers of power plants, geothermal power generators, and OTEC

    International Nuclear Information System (INIS)

    Because of its excellent corrosion resistance to sea water, titanium has increasingly been used in condensers in power plants. Air-cooling units of the condensers have for a long time used titanium tubes for preventing problems caused by ammonia. But recently, condensers using both titanium tube plates and titanium tubes have been made. Also, in a binary circle test plant, which reuses hot water in a geothermal power generator, titanium was used in heat exchangers for its high corrosion resistance to hot water. In a test plant for ocean thermal energy conversion, titanium tubes and tube plates are used. This paper explains the use of titanium in such heat exchangers. (author)

  11. Nuclear power plant waste heat horticulture. Final report, October 1976-September 1977

    International Nuclear Information System (INIS)

    The report gives results of a study of the feasibility of using low grade (700F) waste heat from the condenser cooling water of the Vermont Yankee nuclear plant for commercial food enhancement. The study addressed the possible impact of laws on the use of waste heat from a nuclear plant for food production, alternative greenhouse designs suitable for the site, and an economic and marketing model for greenhouse crops. The low temperature of the waste heat source suggested that supplemental greenhouse heating will be required (a biogas facility using wastes from a dairy herd near the plant was proposed as being economically attractive). A greenhouse design employing heaters using methane from the proposed biogas facility and a cropping schedule for the greenhouses was recommended. The report includes the computer program used to determine the costs of greenhouse production in the Northeast

  12. Energy savings in industrial NH/sub 3/ plant by heat recovery in the waste heat system

    Energy Technology Data Exchange (ETDEWEB)

    Weber, H.; Graeve, H.W.; Herbort, H.J.; Marsch, H.D.

    1984-05-01

    Minimization of energy consumption is nowadays a primary goal in the design of NH/sub 3/ plant. In this context two aspects are particularly important: first, the process steps and their combination must be selected in such a way that the level of energy that has to be supplied to the plant is kept low from the very beginning; second, heat recovery must be optimized by the choice of process conditions and use of appropriate equipment. An industrial NH/sub 3/ plant built according to these principles can operate at a consumption of as low as 29.5 GJ/t NH/sub 3/, using proven processes and equipment. The first plant of this new generation with a capacity of 1120 t/d is currently under construction for Canadian Industries Ltd. (CIL) in Canada.

  13. Application of heat storage in increasing operating flexibility of newly built WWER type reactor power plants in the CSSR for peak electric power generation and for offsetting plant capacity decrease due to heat supply

    International Nuclear Information System (INIS)

    In order to increase the production of electric energy during power peaks a method is suggested for heat storage. At the Dukovany nuclear power plant this is the heat storage in hot feed water based on heating a greater amount of turbine condensate. At the Jaslovske Bohunice nuclear power plant V-2 the possibility is being studied of securing heat offtake from the condensing turbines, this both for power and heating purposes. At the Mochovce nuclear power plant V-4 they are concerned with a combined generation of power and heat from the heating process water of turbines with modified design. The operation is described of the heat offtake from the heating process water at the Temelin nuclear power plant V-5. (M.D.)

  14. Geothermal power plants of Mexico and Central America: a technical survey of existing and planned installations

    Energy Technology Data Exchange (ETDEWEB)

    DiPippo. R.

    1978-07-01

    In this report, the fifth in a series describing the geothermal power plants of the world, the countries of Mexico and of Central America are studied. The geothermal plants are located in areas of recent and active volcanism; the resources are of the liquid-dominated type. Details are given about the plants located at Cerro Prieto in Mexico and at Ahuachapan in El Salvador. In both cases, attention is paid to the geologic nature of the fields, the well programs, geofluid characteristics, energy conversion systems, materials of construction, effluent handling systems, economic factors and plant operating experience. Exploration and development activities are described for other promising geothermal areas in Mexico and El Salvador, along with those in the countries of Costa Rica, Nicaragua, Guatemala, Honduras, and Panama.

  15. A study of a small nuclear power plant system for district heating

    International Nuclear Information System (INIS)

    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. Specific features of combined generation of electric power, heat, and cold by combined-cycle plants

    Science.gov (United States)

    Klimenko, A. V.; Agababov, V. S.; Rogova, A. A.; Tideman, P. A.

    2015-03-01

    Trigeneration systems based on the combined-cycle plants of condensation type and the combined-cycle plants of cogeneration type of several possible structures for the simultaneous generation of heat and cold are developed. Two types of their operational modes are considered: trigeneration complexes with separate and simultaneous generation of heat and cold. In the first case, two assemblies (thermotransformers) of different types are used for generation of heat and cold, one of which is designed to generate heat and the second to generate cold. In the second case, the heat and cold are generated simultaneously in one thermotransformer. In the article, the results of thermodynamic analysis and calculations of technical and economic efficiency of the developed trigeneration systems are presented.

  17. Optimization of a local district heating plant under fuel flexibility and performance

    DEFF Research Database (Denmark)

    Rudra, Souman; Rosendahl, Lasse; From, Niels

    2011-01-01

    Brovst is a small district in Denmark. Based on the case of Brovst, this paper analyses the role of district heating in future Renewable Energy Systems. The present use of fossil fuels in the Brovst DHP (district heating plant) represents an increasing environmental and climate-related load. So, an...... investigation has been made to reduce the use of fossil fuels for district heating system and make use of the local renewable resources (Biogas, Solar and Geothermal) for district heating purpose. In this article, the techno-economic assessment is achieved through the development of a suite of models that are...... energyPRO which has been used to analyses the integration of large scale energy system into the domestic district heating system. A model of the current work on the basis of information from the plant (using fossil fuel) is established and named as a reference model. Then different solutions are...

  18. Feasibility study on development of plate-type heat exchanger for BWR plants

    International Nuclear Information System (INIS)

    In order to apply plate-type heat exchanger to RCW, TCW and FPC system in BWR plants, heat test and seismic test of RCW system heat exchanger sample were carried out. The results of these tests showed new design plate-type heat exchanger satisfied the fixed pressure resistance and seismic resistance and keep the function. The evaluation method of seismic design was constructed and confirmed by the results of tests. As anti-adhesion measure of marine organism, an ozone-water circulation method, chemical-feed method and combination of circulation of hot water and air bubbling are useful in place of the chlorine feeding method. Application of the plate-type heat exchanger to BWR plant is confirmed by these investigations. The basic principles, structure, characteristics, application limit and reliability are stated. (S.Y.)

  19. Process integration in bioprocess indystry: waste heat recovery in yeast and ethyl alcohol plant

    International Nuclear Information System (INIS)

    The process integration of the bioprocess plant for production of yeast and alcohol was studied. Preliminary energy audit of the plant identified the huge amount of thermal losses, caused by waste heat in exhausted process streams, and reviled the great potential for energy efficiency improvement by heat recovery system. Research roadmap, based on process integration approach, is divided on six phases, and the primary tool used for the design of heat recovery network was Pinch Analysis. Performance of preliminary design are obtained by targeting procedure, for three process stream sets, and evaluated by the economic criteria. The results of process integration study are presented in the form of heat exchanger networks which fulfilled the utilization of waste heat and enable considerable savings of energy in short payback period.

  20. 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

  1. New steels for fossil-fired power plants; De nouveaux aciers pour les centrales thermiques classiques

    Energy Technology Data Exchange (ETDEWEB)

    Prunier, V.

    1996-10-01

    Most utilities are determined to enhance the efficiency of their fossil-fired power plants. Related industrial firms are showing an increasing interest in what are known as `supercritical` or `ultra-supercritical` power plants. In these new plants, efficiency is enhanced by increasing the steam temperature and pressure. Conditions aimed at are as follows: T {approx} 580-600 deg and P {approx} 250 bar for supercritical and T {approx} 650 deg C and P {approx} 300-350 bar for ultra-supercritical. Main limiting factors for increasing efficiency are unquestionably related to materials. The new creep, fatigue and corrosion requirements call for substantial research, ensuring that new grades of alloys are regularly propose. The relevance for EDF of higher efficiency plants has led us to define a work program aimed at better acquaintance with materials which could be used in such installations. These materials are also interesting in older plants, where they would enable the thickness of major components to be considerably reduced. The present document is a bibliographical study in two parts. We first present the main alloys suitable for the manufacture of components subjected to creep, thermal fatigue or corrosion in fossil-fired power plants. We identify in particular the first steel grades used in former plants and those recently developed for improved efficiency supercritical or ultra-supercritical plants. We then give details on the main mechanical and structural properties of the eight most interesting alloys: 2.25Cr-1Mo steel, most frequently encountered in operating plants; HCM2S steel, used for the manufacture of water panels tubes without post welding heat treatment; modified 9 Cr-1Mo steel, the international reference for thick components; NF616, HCM12A and NF12 steels for thick components in improved efficiency plants; TP347HFG and NF709 steels for tubes in improved efficiency plants. (author) 40 refs.

  2. Study concerning the erection within the precincts of INR Pitesti of TRIGA prototype nuclear heating plant

    International Nuclear Information System (INIS)

    This paper presents the problems of nuclear plant energy production as heating source for industrial processes and urban district heating. The study is based on the TRIGA concept due to some of its advantages in comparison with other concepts. The system solutions for a prototype implementation and the aspects of the economical and financial efficiency are outlined. The conclusion is drawn that the TRIGA 53 MWt-reactor is suitable to meet the heating needs of urban and industrial heating systems in this country

  3. Heat exchanger design considerations for high temperature gas-cooled reactor (HTGR) plants

    International Nuclear Information System (INIS)

    Various aspects of the high-temperature heat exchanger conceptual designs for the gas turbine (HTGR-GT) and process heat (HTGR-PH) plants are discussed. Topics include technology background, heat exchanger types, surface geometry, thermal sizing, performance, material selection, mechanical design, fabrication, and the systems-related impact of installation and integration of the units in the prestressed concrete reactor vessel. The impact of future technology developments, such as the utilization of nonmetallic materials and advanced heat exchanger surface geometries and methods of construction, is also discussed

  4. A Preliminary Study on Rainfall Interception Loss and Water Yield Analysis on Arabica Coffee Plants in Central Aceh Regency, Indonesia

    OpenAIRE

    Reza Benara; Maimun Rizalihadi; B.C. Alfiansyah Yulianur

    2012-01-01

    Rainfall interception loss from plants or trees can reduce a net rainfall as source of water yield. The amount of rainfall interception loss depends on kinds of plants and hydro-meteorological characteristics. Therefore, it is important to study rainfall interception loss such as from Arabica Coffee plantation which is as main agricultural commodity for Central Aceh Regency. In this study, rainfall interception loss from Arabica Coffee plants was studied in Kebet Village of Central Aceh Regen...

  5. Recycled Water Reuse Permit Renewal Application for the Central Facilities Area Sewage Treatment Plant

    Energy Technology Data Exchange (ETDEWEB)

    Mike Lewis

    2014-09-01

    This renewal application for a Recycled Water Reuse Permit is being submitted in accordance with the Idaho Administrative Procedures Act 58.01.17 “Recycled Water Rules” and the Municipal Wastewater Reuse Permit LA-000141-03 for continuing the operation of the Central Facilities Area Sewage Treatment Plant located at the Idaho National Laboratory. The permit expires March 16, 2015. The permit requires a renewal application to be submitted six months prior to the expiration date of the existing permit. For the Central Facilities Area Sewage Treatment Plant, the renewal application must be submitted by September 16, 2014. The information in this application is consistent with the Idaho Department of Environmental Quality’s Guidance for Reclamation and Reuse of Municipal and Industrial Wastewater and discussions with Idaho Department of Environmental Quality personnel.

  6. Plant diversity-productivity patterns in the alpine steppe environment of the Central Tianshan Mountains

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The biodiversity-productivity relationship is an important topic in the research of bio- diversity and ecosystem function. The plant diversity-productivity pattern is commonly unimodal and positively correlated. This paper researches the characteristics of plant diversity-productivity patterns in the Bayanbuluk alpine steppe in the central Tianshan Mountains, Xinjiang, China, and analyzes the effects of environmental factors on the distribution of plant communities, species composition, plant diversity and productivity in the steppe. The results show a positive correlation between plant diversity and productivity. DCCA (detrended canonical correspondence analysis) ordination reveals a significant relationship between the effects of air temperature, soil moisture content, available soil nitrogen, relative humidity and pH value on the distribution and composition of plant communities. There are significant correlations between the soil moisture content, relative humidity, pH value, air temperature and species richness and the aboveground biomass of Gramineae and Cyperaceae, and also significant correlations between the relative humidity, pH values and the total aboveground biomass of plant communities.

  7. Plant mineral concentrations related to foraging preferences of western lowland gorilla in Central African forest clearings.

    Science.gov (United States)

    Metsio Sienne, Julia; Buchwald, Rainer; Wittemyer, George

    2014-12-01

    In the Central African rain forest, mineral resources essential to organisms are distributed heterogeneously. Forest clearings, locally known as bais, attract numerous species presumably due to the mineral richness of these sites, though understanding of the factors drawing species to bais remains speculative. Western lowland gorillas (Gorilla g. gorilla) selectively feed on particular plant species and parts within bais, but studies of such feeding preferences have focused on one site. Here, we compared concentrations of minerals and macronutrients from plants gorillas consumed and those they did not in 16 bais to gain inference regarding drivers of resource selection within bais and bai use. The availability of gorilla feeding plants varied between surveyed bais, with some consumed species occurring only at a few bais. Regardless of bai specific species composition, significantly higher concentrations of Na, K, and Ca were found in consumed plants, and other trace minerals were more common in consumed plants. In contrast, macronutrients appeared to play no major role in feeding plant selectivity with consumed species often having lower concentrations than non-consumed species. We found evidence for seasonal differences in Mg and Na concentrations, but the concentrations of other minerals in consumed plants were consistent across time. These findings provide insight to the drivers of bai visitation by gorillas. The high variation in species across bais may elicit use of multiple bais, but the general increased mineral composition of consumed species across bais suggests metabolic requirements may be met through consumption of a variety of species. PMID:24865332

  8. Cascade: a review of heat transport and plant design issues

    International Nuclear Information System (INIS)

    A conceptual heat transfer loop for Cascade, a centrifugal-action solid-breeder reaction chamber, has been investigated and results are presented. The Cascade concept, a double-cone-shaped reaction chamber, rotates along its horizontal axis. Solid Li2O or other lithium-ceramic granules are injected tangentially through each end of the chamber. The granules cascade axially from the smaller radii at the ends to the larger radius at the center, where they are ejected into a stationary granule catcher. Heat and tritium are then removed from the granules and the granules are reinjected into the chamber. A 50% dense Li2O granule throughput of 2.8 m3/s is transferred from the reaction chamber to the steam generators via continuous bucket elevators. The granules then fall by gravity through 4 vertical steam generators. The entire transport system is maintained at the same vacuum conditions present inside the reaction chamber

  9. Design of heat exchanger for heating UF6 feed in nuclear fuel element plant

    International Nuclear Information System (INIS)

    The process of conversion of UF6 to UO2 through Integrated Dry Route (IDR) is done in a rotary kiln reactor. There are two stages of initial treatment / conditioning before inserting the UF6 in to the reactor: changing UF6 solid into the gas phase at a temperature of 60°C in an evaporator, and then, raising the temperature of UF6 gas from 60°C to 290°C in a Heat Exchanger (HE). Therefore it is necessary to design a HE for heating UF6 gas by determination / calculation of HE specifications as a heater. The steps activities of determining the specifications of HE in the Following sequence: determining the value of the heat load Q, determining the approximate dimensions of the Heat Exchanger, determining the dimensions / specifications corrected Heat Exchanger, HE pressure drop calculation. The result of this design specification is a type of hairpin double pipe HE with a length of 12 ft, 2 x 1 ¼. IPS. Pipe material is Inconel (alloy -600) that is resistant to UF6, HF, and Steam. Annulus material is carbon steel. Pressure drop in annulus is 0.0004 psi, and in inner pipe is 0.042 psi. Heat Exchanger with specs like this can function as UF6 gas heater so that the temperature be 290°C. (author)

  10. Controversy over Biomass Plant at Florida State Heats up

    Science.gov (United States)

    Mangan, Katherine

    2009-01-01

    This article reports that Florida State University officials are gearing up for what could be another bruising battle this month over a proposed biomass plant that could bring the campus cleaner, cheaper energy and monetary support for alternative-energy research. Or, it could bring noise and pollution to a nearby neighborhood, according to…

  11. Analytical characteristics of dyes extracted from dye plants in Central Africa

    International Nuclear Information System (INIS)

    The aim of this study is to contribute to the valorization of the tinctorial plants of Central Africa. A chemical characterization was conducted on three vegetable species presumed tinctorial. Grewia coriacea Mast (Malvaceae), Harungana madagascariensis Lamex Poir. (Hypericaceae), Annickia chlorantha Oliv. (Annonaceae) were selected because of their traditional use as colouring agents. The classical extractions were done by means of TLC, and quantified by usual methods. The antioxidant activity for the three species has also been assessed.(author)

  12. Wastewater Land Application Permit LA-000141 Renewal Information for the Central Facilities Area Sewage Treatment Plant

    Energy Technology Data Exchange (ETDEWEB)

    Laboratory, Idaho National

    1999-02-01

    On July 25, 1994, the State ofldaho Division of Environmental Quality (DEQ) issued a Wastewater Land Application Permit (WLAP) for the Idaho National Engineering Laboratory's (INEL, now the Idaho National Engineering and Environmental Laboratory [INEEL]) Central Facilities Area (CFA) Sewage Treatment Plant (STP). The permit expires August 7, 1999. In addition to the renewal application, this report was prepared to provide the following information as requested by DEQ.

  13. Plant biodiversity of beech forests in central-northern Italy: a methodological approach for conservation purposes

    OpenAIRE

    Marcantonio M; Chiarucci A; Maccherini S; Guglietta D; Bacaro G

    2012-01-01

    Forests are reckoned essentials as biodiversity reservoirs and carbon sinks. Current threats to forest ecosystems (e.g., climate changes, habitat loss and fragmentation, management changes) call for monitoring their biodiversity and preserving their ecological functions. In this study, we characterized plants diversity of five beech forests located in central and north Apennines mountain chain, using results by a probabilistic sampling. In order to achieve our goals, we have considered specie...

  14. IAEA activities to improve occupational radiation protection in nuclear power plants in Central and Eastern Europe

    International Nuclear Information System (INIS)

    The following aspects are highlighted: developing standards, ISOE (Information System on Occupational Exposure), providing assistance, and intercomparisons. By means of these coordinated efforts, the IAEA aims at improving occupational radiation protection in nuclear power plants in Central and Eastern Europe. The objective is not only transfer of knowledge and technology but also encouraging cooperation between health physicists in those countries as well as with health physicists in Western countries. (P.A.)

  15. 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.

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

    International Nuclear Information System (INIS)

    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 105 kg/year of fish, 1.5 x 106 kg/year of clam meat, and 1.5 x 104 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

  17. Electric protections based in microprocessors in power plants; Protecciones electricas basadas en microprocesadores en centrales generadoras

    Energy Technology Data Exchange (ETDEWEB)

    Libreros, Domitilo; Castanon Jimenez, Jose Ismael [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1987-12-31

    This article is centered around the substitution of the conventional electric protections of a power plant in connection type unit for protections based in microprocessors. A general model of conventional protection of a power plant is described and the number of analogic and digital signals that intervene in that model are quantified. A model is setup for power plant protection with microprocessors, analyzing each one of the modules that would form it. Finally, the algorithms to carry on such protection are presented. [Espanol] Este articulo se centra en torno a la sustitucion de las protecciones electricas convencionales de una central generadora en conexion tipo unidad por protecciones basadas en microprocesadores. Se describe el modelo general de proteccion convencional de una central generadora y se cuantifica el numero de senales analogicas y digitales que interviene en dicho modelo. Se propone un modelo para proteccion de centrales generadoras mediante microprocesadores, analizandose cada uno de los modulos que lo conformarian. Finalmente, se presentan los algoritmos para realizar dicha proteccion.

  18. Effectiveness of a large mimic panel in an existing nuclear power plant central control board

    International Nuclear Information System (INIS)

    We conducted the analysis of the nuclear power plant (NPP) operators' behaviors under emergency conditions by using training simulators as a joint research project by Japanese BWR groups for twelve years. In the phase-IV of this project we executed two kinds of experiments to evaluate the effectiveness of the interfaces. One was for evaluations of the interfaces such as CRTs with touch screen, a large mimic panel, and a hierarchical annunciator system introduced in the newly developed ABWR type central control board. The other was that we analyzed the operators' behaviors in emergency conditions by using the first generation BWR type central control board which was added new interfaces such as a large display screen and demarcation on the board to help operators to understand the plant. The demarcation is one of the visual interface improvements and its technique is that a line enclosing several components causes them to be perceived as a group.The result showed that both the large display panel Introduced in ABWR central control board and the large display screen in the existing BWR type central control board improved the performance of the NPP operators in the experiments. It was expected that introduction of the large mimic panel into the existing BWR type central control boards would improve operators' performance. However, in the case of actual installation of the large display board into the existing central control boards, there are spatial and hardware constraints. Therefore the size of lamps, lines connecting from symbols of the pumps or valves to the others' will have to be modified under these constraints. It is important to evaluate the displayed information on the large display board before actual installation. We made experiments to solve these problems by using TEPCO's research simulator which is added a large mimic panel. (author)

  19. Heat flow and subsurface temperature distributions in central and western New York. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hodge, D.S.; Fromm, K.

    1984-01-01

    Initiation of a geothermal energy program in western and central New York requires knowledge of subsurface temperatures for targeting areas of potential resources. The temperature distribution in possible geothermal reservoirs, calculated from heat flow measurements and modeling techniques, shows that a large area of New York can be considered for exploitation of geothermal resources. Though the temperatures at currently accessible depths show the availability of only a low-temperature (less than 100/sup 0/C), direct-use resource, this can be considered as an alternative for the future energy needs of New York State. From analysis of bottom-hole-temperature data and direct heat flow measurements, estimates of temperatures in the Cambrian Sandstones provide the basis of the economic evaluation of the reservoir. This reservoir contains the extractable fluids needed for targeting a potential geothermal well site in the low-temperature geothermal target zone. In the northern section of the Appalachian basin, reservoir temperatures in the Cambrian are below 50/sup 0/C but may be over 80/sup 0/C in the deeper parts of the basin in southern New York State. Using a minimum of 50/sup 0/C as a useful reservoir temperature, temperatures in excess of this value are encountered in the Theresa Formation at depths in excess of 1300 meters. Considering a maximum depth for economical drilling to be 2500 meters with present technology, the 2500 meters to the Theresa (sea level datum) forms the lower limit of the geothermal resource. Temperatures in the range of 70/sup 0/C to 80/sup 0/C are predicted for the southern portion of New York State.

  20. Emission analysis of the best available wood-fired central heating boilers on the market

    International Nuclear Information System (INIS)

    The purpose of the present project is to study the emissions from some of the best available wood-fired central heating boilers on the market. The aim is to identify the critical factors which determine the emission levels by means of emission measurements as well as temperature measurements in the combustion chamber. Four boilers with different design characteristics have been included in the project. All boilers use reversed combustion and fan-assisted combustion air supply, and have shown low tar emissions in earlier environmental tests. Boiler A is a boiler with a rather large mass of ceramics in the grate and in the burn-out zone, and a large volume of water. Boiler B has a smaller mass in the cast-iron grate and in the burn-out zone and a small water volume. Boiler C is a boiler with tertiary air and an incorporated accumulator tank. Boiler D has a zirconia-cell probe for continuous control of the air-excess ratio. The measurements have been made with the boilers in accumulator operation, i.e. at maximum heat output, since they are intended for this type of operation. Tests have, in addition to normal operating conditions, been made with high fuel moisture contents, high draught and a low boiler temperature at the start of the test. Measurements have been made of excess-air ratios, contents of CO, total hydrocarbons (THC), NOx and a number of volatile organic compounds (VOC) in the flue gases as well as of combustion temperatures below the grate

  1. Simulation of solar chimney power plant with an external heat source

    International Nuclear Information System (INIS)

    Solar chimney power plant is a sustainable source of power production. The key parameter to increase the system power output is to increase its size but the plant cannot operate during night hours. This study deals with simulation work to validate results of pilot plant at Manzanares and include the effects of waste heat from a gas turbine power plant in the system. The effects show continuous night operation, a 38.8 percent increase in power at 1000 W/m2 global solar irradiation at daytime and 1.14 percent increase in overall efficiency.

  2. Simulation of solar chimney power plant with an external heat source

    Science.gov (United States)

    Islamuddin, Azeemuddin; Al-Kayiem, Hussain H.; Gilani, Syed I.

    2013-06-01

    Solar chimney power plant is a sustainable source of power production. The key parameter to increase the system power output is to increase its size but the plant cannot operate during night hours. This study deals with simulation work to validate results of pilot plant at Manzanares and include the effects of waste heat from a gas turbine power plant in the system. The effects show continuous night operation, a 38.8 percent increase in power at 1000 W/m2 global solar irradiation at daytime and 1.14 percent increase in overall efficiency.

  3. Recent severe heat waves in central Europe: how to view them in a long-term prospect?

    Czech Academy of Sciences Publication Activity Database

    Kyselý, Jan

    2010-01-01

    Roč. 30, č. 1 (2010), s. 89-109. ISSN 0899-8418 R&D Projects: GA ČR GC205/07/J044 Institutional research plan: CEZ:AV0Z30420517 Keywords : heat wave * climate variability * regional warming * stochastic modelling * probability estimates * central Europe Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 2.479, year: 2010

  4. Drought increases the freezing resistance of high-elevation plants of the Central Chilean Andes.

    Science.gov (United States)

    Sierra-Almeida, Angela; Reyes-Bahamonde, Claudia; Cavieres, Lohengrin A

    2016-08-01

    Freezing temperatures and summer droughts shape plant life in Mediterranean high-elevation habitats. Thus, the impacts of climate change on plant survival for these species could be quite different to those from mesic mountains. We exposed 12 alpine species to experimental irrigation and warming in the Central Chilean Andes to assess whether irrigation decreases freezing resistance, irrigation influences freezing resistance when plants are exposed to warming, and to assess the relative importance of irrigation and temperature in controlling plant freezing resistance. Freezing resistance was determined as the freezing temperature that produced 50 % photoinactivation [lethal temperature (LT50)] and the freezing point (FP). In seven out of 12 high-Andean species, LT50 of drought-exposed plants was on average 3.5 K lower than that of irrigated plants. In contrast, most species did not show differences in FP. Warming changed the effect of irrigation on LT50. Depending on species, warming was found to have (1) no effect, (2) to increase, or (3) to decrease the irrigation effect on LT50. However, the effect size of irrigation on LT50 was greater than that of warming for almost all species. The effect of irrigation on FP was slightly changed by warming and was sometimes in disagreement with LT50 responses. Our data show that drought increases the freezing resistance of high-Andean plant species as a general plant response. Although freezing resistance increases depended on species-specific traits, our results show that warmer and moister growing seasons due to climate change will seriously threaten plant survival and persistence of these and other alpine species in dry mountains. PMID:27053321

  5. Energy efficiency analysis of condensed waste heat recovery ways in cogeneration plant

    International Nuclear Information System (INIS)

    Highlights: • The heating equivalent electricity method is used to analyze energy efficiencies. • Analysis is made combining with the characteristics of the steam turbines. • Main factors affecting energy efficiencies of the common heating ways are analyzed. • Applicability evaluations of the heating ways are made under design conditions. - Abstract: Making full use of condensed waste heat is an effective approach to increase heating capacity and reduce air pollutant emissions of the cogeneration plant. In this article, the heating equivalent electricity method is adopted to evaluate energy efficiencies and applicability of different condensed waste heat recovery ways, such as the condenser, the single-effect lithium bromide absorption heat pump and the bleeding-steam-driven compression heat pump. The following discussion is based on a 300 MW water-cooling steam turbine heating system and a 300 MW air-cooling steam turbine heating system. Combining with the characteristics of the water-cooling steam turbine and the air-cooling steam turbine, main factors affecting energy efficiencies are analyzed. Applicability evaluations of these condensed waste heat recovery ways are made by comparing energy efficiencies with each other under design conditions. Analysis shows that direct heat exchange by the condenser should be given the first priority. The condenser is most suitable to provide basic heating load. For the heat source composed of several steam turbines, the corresponding condensers should be connected in series. The proportion of steam turbines with high backpressures should be controlled due to high energy consumptions and inflexibility of adjustment. When supply water temperature is low, a surplus of bleeding steam pressure causes large irreversible loss in the generator of the single-effect absorption heat pump. A waste of energy grade of the bleeding steam makes the energy efficiency of the single-effect absorption heat pump lower than that of the

  6. Mycorrhizal status of plant species in the Chaco Serrano Woodland from central Argentina.

    Science.gov (United States)

    Fracchia, Sebastian; Aranda, Adriana; Gopar, Analia; Silvani, Vanesa; Fernandez, Laura; Godeas, Alicia

    2009-03-01

    We examined the mycorrhizal type of 128 plant species in two patches of native vegetation of the Chaco Serrano Woodland, central Argentina, the largest dry forest area in South America. Of the 128 plant species investigated (belonging to 111 genera in 53 families), 114 were colonized by arbuscular mycorrhizal fungi (AM), orchid mycorrhizal associations were present in the five terrestrial orchid species analyzed, one ectomycorrhiza was only present in Salix humboldtiana Willd., and 96 harbored a dark septate endophyte (DSE) association. Co-occurrence of AM and DSE was observed in 88 plant species. We determine morphological types of arbuscular mycorrhizal fungi (Arum, Paris, and intermediate AM structures) and report the mycorrhizal status in 106 new species, 12 of which are endemic to central Argentina and two, Aa achalensis Schltr. and Buddleja cordobensis Griseb., are declared to be vulnerable species. Root colonization in the Chaco Serrano Woodland is widespread and should be considered in revegetation programs due to the deterioration of this particular ecosystem. Considering the predominance of AM and DSE associations and the various potential benefits that these associations may bring to plant establishment, they should receive special attention in conservation and reforestation of these woodlands. PMID:19184128

  7. Improving the turbine district heating installations of single-circuit nuclear power plants

    Science.gov (United States)

    Kondurov, E. P.; Kruglikov, P. A.; Smolkin, Yu. V.

    2015-10-01

    Ways for improving the turbine district heating installations of single-circuit nuclear power plants are considered as a possible approach to improving the nuclear power plant energy efficiency. The results of thermal tests carried out at one of single-circuit NPPs in Russia with a view to reveal the possibilities of improving the existing heat-transfer equipment of the turbine district heating installation without making significant investments in it were taken as a basis for the analysis. The tests have shown that there is certain energy saving potential in some individual units and elements in the turbine district heating installation's process circuit. A significant amount of thermal energy can be obtained only by decreasing the intermediate circuit temperature at the inlet to the heater of the first district-heating extraction. The taking of this measure will also lead to an additional amount of generated electricity because during operation with the partially loaded first heater, the necessary amount of heat has to be obtained from the peaking heater by reducing live steam. An additional amount of thermal energy can also be obtained by eliminating leaks through the bypass control valves. The possibility of achieving smaller consumption of electric energy for power plant auxiliaries by taking measures on reducing the available head in the intermediate circuit installation's pump unit is demonstrated. Partial cutting of pump impellers and dismantling of control valves are regarded to be the most efficient methods. The latter is attributed to qualitative control of the turbine district heating installation's thermal load. Adjustment of the noncondensable gas removal system will make it possible to improve the performance of the turbine district heating installation's heat-transfer equipment owing to bringing the heat-transfer coefficients in the heaters to the design level. The obtained results can be used for estimating the energy saving potential at other

  8. Ethnomedicinal plants used by the people of Manang district, central Nepal

    Directory of Open Access Journals (Sweden)

    Chaudhary Ram P

    2006-10-01

    Full Text Available Abstract Background The district of Manang (2000 – 6000 m is located in the Central Himalayas, Nepal. The majority of local inhabitants of the area are Gurungs, of Tibetan origin. The remoteness of the region has resulted in continued use of plants as medicine in an area where the ethnobotany has sparsely been documented. Methods Interviews were conducted with amchi (Tibetan medicinal practitioners, local healers (including priests locally known as 'lamas', plant traders, and knowledgeable villagers (including herders regarding local plant names and their medicinal uses during several field visits (2002–2005. When convenient to the locals, a jungle or forest walk was done with the healers, allowing for both plant collection and detailed information gathering. Results This present research documented 91 ethnomedicinal plant species, belonging to 40 families under 73 genera, and 45 new ethnomedicinal plant species are added. These 91 locally used medicinal plants are found to treat 93 ailments. This study provides information on 45 plant species previously unknown for their medicinal uses in Manang. The indication for use, mode of preparation, dose and administration of medicine are described in detail for each species. Conclusion This wealth of ethnobotanical knowledge persists, and is being transferred to the next generation in some areas in upper Manang, in a country where this is often not the case. The senior amchi of the area (Karma Sonam Lama, who has been practicing Tibetan medicine for three generations, feels that it is of utmost importance to conserve the traditional healing system and to pass his knowledge on to the local community about the importance of medicinal plants. He hopes that this will lead to the conservation and sustainable management of medicinal plants in the villages. Over the duration of this research, the prices of several rare medicinal plants of Manang increased dramatically, highlighting both the scarcity and

  9. Effect of heating rate and plant species on the size and uniformity of silver nanoparticles synthesized using aromatic plant extracts

    Science.gov (United States)

    Hernández-Pinero, Jorge Luis; Terrón-Rebolledo, Manuel; Foroughbakhch, Rahim; Moreno-Limón, Sergio; Melendrez, M. F.; Solís-Pomar, Francisco; Pérez-Tijerina, Eduardo

    2016-05-01

    Mixing aqueous silver solutions with aqueous leaf aromatic plant extracts from basil, mint, marjoram and peppermint resulted in the synthesis of quasi-spherical silver nanoparticles in a range of size between 2 and 80 nm in diameter as analyzed by analytical high-resolution electron microscopy. The average size could be controlled by applying heat to the initial reaction system at different rates of heating, and by the specific botanical species employed for the reaction. Increasing the rate of heating resulted in a statistically significant decrease in the size of the nanoparticles produced, regardless of the species employed. This fact was more evident in the case of marjoram, which decreased the average diameter from 27 nm at a slow rate of heating to 8 nm at a high rate of heating. With regard to the species, minimum sizes of mint yielded an average size between 10 and 25 nm. The results indicate that aromatic plant extracts can be used to achieve the controlled synthesis of metal nanoparticles.

  10. Solar heat storages in district heating networks

    Energy Technology Data Exchange (ETDEWEB)

    Ellehauge, K. (Ellehauge og Kildemoes, AArhus (DK)); Engberg Pedersen, T. (COWI A/S, Kgs. Lyngby (DK))

    2007-07-15

    This report gives information on the work carried out and the results obtained in Denmark on storages for large solar heating plants in district heating networks. Especially in Denmark the share of district heating has increased to a large percentage. In 1981 around 33% of all dwellings in DK were connected to a district heating network, while the percentage in 2006 was about 60% (in total 1.5 mio. dwellings). In the report storage types for short term storage and long term storages are described. Short term storages are done as steel tanks and is well established technology widely used in district heating networks. Long term storages are experimental and used in connection with solar heating. A number of solar heating plants have been established with either short term or long term storages showing economy competitive with normal energy sources. Since, in the majority of the Danish district heating networks the heat is produced in co-generation plants, i.e. plants producing both electricity and heat for the network, special attention has been put on the use of solar energy in combination with co-generation. Part of this report describes that in the liberalized electricity market central solar heating plants can also be advantageous in combination with co-generation plants. (au)

  11. Themoeconomic optimization of triple pressure heat recovery steam generator operating parameters for combined cycle plants

    OpenAIRE

    Mohammd Mohammed S.; Petrović Milan V.

    2015-01-01

    The aim of this work is to develop a method for optimization of operating parameters of a triple pressure heat recovery steam generator. Two types of optimization: (a) thermodynamic and (b) thermoeconomic were preformed. The purpose of the thermodynamic optimization is to maximize the efficiency of the plant. The selected objective for this purpose is minimization of the exergy destruction in the heat recovery steam generator (HRSG). The purpose of the ther...

  12. Heat pipe air preheater for gas-/oil-fired power plants

    International Nuclear Information System (INIS)

    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

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

    OpenAIRE

    Florian Heberle; Dieter Brüggemann

    2014-01-01

    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...

  14. Steam generators and waste heat boilers for process and plant engineers

    CERN Document Server

    Ganapathy, V

    2014-01-01

    Incorporates Worked-Out Real-World ProblemsSteam Generators and Waste Heat Boilers: For Process and Plant Engineers focuses on the thermal design and performance aspects of steam generators, HRSGs and fire tube, water tube waste heat boilers including air heaters, and condensing economizers. Over 120 real-life problems are fully worked out which will help plant engineers in evaluating new boilers or making modifications to existing boiler components without assistance from boiler suppliers. The book examines recent trends and developments in boiler design and technology and presents novel idea

  15. The heat transport system and plant design for the HYLIFE-2 fusion reactor

    International Nuclear Information System (INIS)

    HYLIFE is the name given to a family of self-healing liquid-wall reactor concepts for inertial confinement fusion. This HYLIFE-II concept employs the molten salt, Flibe, for the liquid jets instead of liquid lithium used in the original HYLIFE-I study. A preliminary conceptual design study of the heat transport system and the balance of plant of the HYLIFE-II fusion power plant is described in this paper with special emphasis on a scoping study to determine the best intermediate heat exchanger geometry and flow conditions for minimum cost of electricity. 11 refs., 8 figs

  16. Some fabrication problems in nuclear power plants heat exchanges, its detectability and implications

    International Nuclear Information System (INIS)

    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)

  17. Steam gasification of coal, project prototype plant nuclear process heat

    International Nuclear Information System (INIS)

    This report describes the tasks, which Bergbau-Forschung has carried out in the field of steam gasification of coal in cooperation with partners and contractors during the reference phase of the project. On the basis of the status achieved to date it can be stated, that the mode of operation of the gas-generator developed including the direct feeding of caking high volatile coal is technically feasible. Moreover through-put can be improved by 65% at minimum by using catalysts. On the whole industrial application of steam gasification - WKV - using nuclear process heat stays attractive compared with other gasification processes. Not only coal is conserved but also the costs of the gas manufactured are favourable. As confirmed by recent economic calculations these are 20 to 25% lower. (orig.)

  18. Efficiency Growth of Combined-cycle Cogeneration Plant with the Heat Supply System

    Directory of Open Access Journals (Sweden)

    Denysova Alla

    2015-08-01

    Full Text Available Energy efficiency of modern technologies of the combined production of heat and electricity and ways of energy saving on base of recycling secondary energy sources has been estimated. It is shown that the most effective for cogeneration are combined-cycle plants. The rational scheme of interaction of combined-cycle cogeneration plant with heat supply system has been offered. Theoretical bases of interaction of main installation with a contour of heat and hot water supply system has been developed. Numerical modeling of temperature parameters and the analysis of results of numerical modeling has been executed. The technology of increase of energy efficiency of installations on base of recycling heat is offered. Increase of effectiveness of system is achieved due to full use of heat and reduction of losses to environment. It is established, that the rational scheme of interaction of combined-cycle cogeneration plant with heat supply system allows increasing energy efficiency on 2 % that corresponds to economy of fuel 3 %.

  19. Mathematical model for solar-hydrogen heated desalination plant using humidification-dehumidification process

    International Nuclear Information System (INIS)

    This paper presents a mathematical model for thermal desalination plant operating with solar energy and hydrogen. This plant is composed of two main systems, the heating system and the distillation system. The distillation system is composed of multi-cells; each cell is using the humidification-dehumidification (H-D) process in the distillation unit and getting the required amount of heat from feed seawater heater. The feed seawater heater is a heat exchanger used to raise the temperature of the preheated seawater coming from the condensation chamber (Dehumidifier) of each cell to about 85 degree centigrade. The heating amount in the heat exchangers is obtained from the thermal storage tank, which gets its energy from solar thermal system and is coupled with a hydrogen-fired backup system to guaranty necessary operating conditions and permit 24 hours solar H-D desalination plant to enhance the performance of this system. The mathematical model studies the performance of the proposed desalination system using thermal solar energy and hydrogen as fuel. Other pertinent variable in the heating and distillation system are also studied. The outcomes of this study are analyzed to enhance the used solar desalination process and make commercial.(Author)

  20. Solar tower power plant using a particle-heated steam generator: Modeling and parametric study

    Science.gov (United States)

    Krüger, Michael; Bartsch, Philipp; Pointner, Harald; Zunft, Stefan

    2016-05-01

    Within the framework of the project HiTExStor II, a system model for the entire power plant consisting of volumetric air receiver, air-sand heat exchanger, sand storage system, steam generator and water-steam cycle was implemented in software "Ebsilon Professional". As a steam generator, the two technologies fluidized bed cooler and moving bed heat exchangers were considered. Physical models for the non-conventional power plant components as air- sand heat exchanger, fluidized bed coolers and moving bed heat exchanger had to be created and implemented in the simulation environment. Using the simulation model for the power plant, the individual components and subassemblies have been designed and the operating parameters were optimized in extensive parametric studies in terms of the essential degrees of freedom. The annual net electricity output for different systems was determined in annual performance calculations at a selected location (Huelva, Spain) using the optimized values for the studied parameters. The solution with moderate regenerative feed water heating has been found the most advantageous. Furthermore, the system with moving bed heat exchanger prevails over the system with fluidized bed cooler due to a 6 % higher net electricity yield.

  1. Mycorrhizas in the Central European flora: relationships with plant life history traits and ecology.

    Science.gov (United States)

    Hempel, Stefan; Götzenberger, Lars; Kühn, Ingolf; Michalski, Stefan G; Rillig, Matthias C; Zobel, Martin; Moora, Mari

    2013-06-01

    Plant traits have been widely used to characterize different aspects of the ecology of plant species. Despite its wide distribution and its proven significance at the level of individuals, communities, and populations, the ability to form mycorrhizal associations has been largely neglected in these studies so far. Analyzing plant traits associated with the occurrence of mycorrhizas in plants can therefore enhance our understanding of plant strategies and distributions. Using a comparative approach, we tested for associations between mycorrhizal status and habitat characteristics, life history traits, and plant distribution patterns in 1752 species of the German flora (a major part of the Central European flora). Data were analyzed using log-linear models or generalized linear models, both accounting for phylogenetic relationships. Obligatorily mycorrhizal (OM) species tended to be positively associated with higher temperature, drier habitats, and higher pH; and negatively associated with moist, acidic, and fertile soils. Competitive species were more frequently OM, and stress tolerators were non-mycorrhizal (NM), while ruderal species did not show any preference. Facultatively mycorrhizal (FM) species showed the widest geographic and ecological amplitude. Indigenous species were more frequently FM and neophytes (recent aliens) more frequently OM than expected. FM species differed markedly from OM and NM species in almost all analyzed traits. Specifically, they showed a wider geographic distribution and ecological niche. Our study of the relationships between mycorrhizal status and other plant traits provides a comprehensive test of existing hypotheses and reveals novel patterns. The clear distinction between FM and OM + NM species in terms of their ecology opens up a new field of research in plant-mycorrhizal ecology. PMID:23923502

  2. Determination and evaluation of the operation characteristics for two configurations of combined heat and power systems depending on the heating plant parameters in low-temperature geothermal applications

    International Nuclear Information System (INIS)

    Highlights: • We analyzed the performances of two CHP plants versus the heating plant parameters. • ORC performance is destructed when raising the heat demand and return temperature. • The low return temperatures enhance the power productivity in the both plants. • The high supply temperature has no impact on ORC in the parallel CHP integration. • The increasing heat demand optimizes the heat source utilization. - Abstract: This paper analyzes impact of the required heating plant parameters on the Organic Rankine Cycle (ORC) power plant and the total plant behavior for two connections of CHP systems; they are the parallel plant and CHP integration according to Glewe-plant, Germany. And also, degree of utilizing the geothermal heat source will be discussed, and all CHP systems presented in the literature will be compared under the same conditions. R134a as working fluid in power plant will be employed. Exergy efficiency, net output power of ORC, irreversibility especially with exhausted geothermal water and the total heat exchange areas will be evaluated. From the calculations, it could be concluded that when operating the power plant in the both aforementioned CHP connections, its performances will be destructed at high heating plant parameters. So the compromised values of the low return temperatures and the heat exchange areas will enhance the power production and the performance of the total CHP systems at unchanged heat demand and supply temperature. The supply temperature does not have any effects on the power generation in case of the parallel connection, while the high values of this temperature affect negatively the other integration. The analysis also proved that the increasing heat demand will reduce the ORC productivity, but it will enhance the heat source utilization. The comparison between the CHP plants showed that the parallel connection is more economical and the series connection is energetically more efficient, while the integration

  3. A Novel Modeling of Molten-Salt Heat Storage Systems in Thermal Solar Power Plants

    Directory of Open Access Journals (Sweden)

    Rogelio Peón Menéndez

    2014-10-01

    Full Text Available Many thermal solar power plants use thermal oil as heat transfer fluid, and molten salts as thermal energy storage. Oil absorbs energy from sun light, and transfers it to a water-steam cycle across heat exchangers, to be converted into electric energy by means of a turbogenerator, or to be stored in a thermal energy storage system so that it can be later transferred to the water-steam cycle. The complexity of these thermal solar plants is rather high, as they combine traditional engineering used in power stations (water-steam cycle or petrochemical (oil piping, with the new solar (parabolic trough collector and heat storage (molten salts technologies. With the engineering of these plants being relatively new, regulation of the thermal energy storage system is currently achieved in manual or semiautomatic ways, controlling its variables with proportional-integral-derivative (PID regulators. This makes the overall performance of these plants non optimal. This work focuses on energy storage systems based on molten salt, and defines a complete model of the process. By defining such a model, the ground for future research into optimal control methods will be established. The accuracy of the model will be determined by comparing the results it provides and those measured in the molten-salt heat storage system of an actual power plant.

  4. Nuclear heat generating plants - technical concepts and market potentials. Chapter 10

    International Nuclear Information System (INIS)

    The export potential of nuclear heat generating plants is discussed giving different countries as an example. In order to keep the relevant investigation expenditure within reasonable limits, an indicator system is developed consisting of the following six stages: basic indicators, economic indicators, industrial indicators, energy indicators, environment indicators, and economic efficiency indicators. The resulting export potential for German nuclear heat generating plants is summarized by countries and criteria. Altogether there are good export potentials for six countries, namely Denmark, France, Poland, Hungary, USSR and Japan. Exports to another 11 countries, namely Finland, Belgium, Switzerland, Austria, Spain, Portugal, the GDR, the CSFR, Bulgaria, China and South Korea, may be possible. Finally it can be said that there are potentials for the export of German nuclear heat generating plants which may fill the order books of the German power plant industry. Since the potential importers are above all East European and Asian countries, the experience gained from the project undertaken with the USSR, and the further development of the political dialogue with those countries, are of major importance for the export potential of German nuclear heat generating plants. (orig./UA)

  5. THE INCREASE EFFICIENCY OF THE HEAT SUPPLY PUBLIC SERVICE BY IMPLEMENTING AN INTEGRATED CENTRALIZED HEATING SUPPLY SYSTEM (SACET) IN THE MUNICIPALITY OF BUCHAREST

    OpenAIRE

    Anamaria-Cristina ANDREI

    2013-01-01

    Under the new European regulations, it becomes a necessity and a priority for Romania to take adequate political, legislative and administrative measures to stop the decline of the centralized heat supply systems. The energy efficiency is the most cost-effective and fastest growing method to improve security of energy supply, reduce energy loss and costs, and greenhouse gas emissions which are responsible for global warming. Cogeneration, notably high efficiency cogeneration and the improved ...

  6. Heat balance in main lakes of central Italy; Bilancio termico dei principali laghi dell`Italia Centrale

    Energy Technology Data Exchange (ETDEWEB)

    Monte, L.; Baldini, E.; Battella, C.; Fratarcangeli, S.; Pompei, F. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dip. Ambiente

    1996-07-01

    A thermodynamic model for predicting the thermal stratification of water of deep lakes and the components of the heat balance of lacustrine systems was developed in the frame of the researches on predictive limnology. The model has been applied to Bracciano, Bolsena and Trasimeno lakes. The validation of the temperature results demonstrated the reliability of the model and, as consequence, of the thermal balances of the lakes. The calculated yearly evaporation is about 800 mm.

  7. Feasibility Assessment of Using Power Plant Waste Heat in Large Scale Horticulture Facility Energy Supply Systems

    OpenAIRE

    Min Gyung Yu; Yujin Nam

    2016-01-01

    Recently, the Korean government has been carrying out projects to construct several large scale horticulture facilities. However, it is difficult for an energy supply to operate stably and economically with only a conventional fossil fuel boiler system. For this reason, several unused energy sources have become attractive and it was found that power plant waste heat has the greatest potential for application in this scenario. In this study, we performed a feasibility assessment of power plant...

  8. Heat Shock Proteins: A Review of the Molecular Chaperones for Plant Immunity

    OpenAIRE

    Park, Chang-Jin; Seo, Young-Su

    2015-01-01

    As sessile organisms, plants are exposed to persistently changing stresses and have to be able to interpret and respond to them. The stresses, drought, salinity, chemicals, cold and hot temperatures, and various pathogen attacks have interconnected effects on plants, resulting in the disruption of protein homeostasis. Maintenance of proteins in their functional native conformations and preventing aggregation of non-native proteins are important for cell survival under stress. Heat shock prote...

  9. Determining Reliability Parameters for a Closed-Cycle Small Combined Heat and Power Plant

    Science.gov (United States)

    Vysokomorny, Vladimir S.; Vysokomornaya, Olga V.; Piskunov, Maxim V.

    2016-02-01

    The paper provides numerical values of the reliability parameters for independent power sources within the ambient temperature and output power range corresponding to the operation under the climatic conditions of Eastern Siberia and the Far East of the Russian Federation. We have determined the optimal values of the parameters necessary for the reliable operation of small CHP plants (combined heat and power plants) providing electricity for isolated facilities.

  10. Study of two control rods of a district heating nuclear plant

    International Nuclear Information System (INIS)

    This paper broaches the study of the control rods to ensure a convenient working during load following of the nuclear reactor THERMOS. The mathematical model is descriptive of the whole of the nuclear plant (point model for the core and the heat balances). Two power control are studied. The first, like PWR, is a program for the mean temperature of primary water. The second takes into account the structure of the plant and is described by a schedule of powers

  11. Detailed study of the heat sink of Saint-Laurent-des-Eaux nuclear plant

    International Nuclear Information System (INIS)

    This work is dedicated to a detailed study of the reliability of the heat sink of the nuclear plant which is situated on the banks of the Loire river. In the first part the requirements the heat sink has to comply with are reviewed, in the second part the various operating modes, the different procedures established to cope with the hazards of the river: icing up, frost, overflow, lowest water, choking are reported. This analysis highlights the good compliance of the heat sink with the specifications but some improvements about periodic testing are proposed. (A.C.)

  12. Fluorescence and heat emission in plants. Use in research on photosynthesis

    International Nuclear Information System (INIS)

    Fluorescence and heat emitted by a leaf can be used for a nondestructive evaluation of photosynthetic parameters in vivo both in basic and applied research. Here it is illustrated how induction kinetics, emission spectra and excitation spectra of both fluorescence and heat can be used to detect the physiological activity of a plant. Photoaccoustic spectroscopy is described as a new, sensitive technique for the detection of heat emission. It enables a more detailed picture of the quantum yield efficiency and provides additional information on the depth profile of a sample

  13. Central African biomes and forest succession stages derived from modern pollen data and plant functional types

    Directory of Open Access Journals (Sweden)

    J. Lebamba

    2009-07-01

    Full Text Available New detailed vegetation reconstructions are proposed in Atlantic Central Africa from a modern pollen data set derived from 199 sites (Cameroon, Gabon and Congo including 131 new sites. In this study, the concept of plant functional classification is improved with new and more detailed plant functional types (PFTs and new aggregations of pollen taxa. Using the biomisation method, we reconstructed (1 modern potential biomes and (2 potential succession stages of forest regeneration, a new approach in Atlantic Central African vegetation dynamics and ecosystem functioning reconstruction. When compared to local vegetation, potential biomes are correctly reconstructed (97.5% of the sites and tropical rain forest (TRFO biome is well identified from tropical seasonal forest (TSFO biome. When the potential biomes are superimposed on the White's vegetation map, only 76.4% of the sites are correctly reconstructed. But using botanical data, correspondence and cluster analyses, the 43 sites from Congo (Mayombe evidence more affinities with those of central Gabon and so they can also be considered as correctly reconstructed as TRFO biome and White's map should be revised. In terms of potential succession stages of forest regeneration, the mature forest (TMFO is well differentiated from the secondary forest (TSFE, but inside this latter group, the young and the pioneer stages are not clearly identified due probably to their low sampling representation. Moreover, linked to their progressive and mosaic character, the boundaries between two forest biomes or two forest stages are not clearly detected and need also a more intensive sampling in such transitions.

  14. Pressurizer level measurement inside PWR nuclear plant using resistance type heat sensors

    International Nuclear Information System (INIS)

    The accident that occured in 1979 to the PWR type nuclear reactor, Three-Mile Island 2, has drawn attention to the maladjustement of the differentiel pressure level detector installed in nuclear plants on the market. A system is presented here for measuring the level in pressurizers based on measurements of the heat resistance of the boundary layer existing between the heated sensor and the fluid mass in the vessel. The sensor consists of a 3 cm diameter cylindrical insulator support around which a 0.1 mm diameter platinum filament is wound. This filament simultaneously fulfills heating and transducer functions. To verify the feasibility of the resistant type heat sensor a test system, which provides water and steam under pressure was realised. Static and dynamic tests have shown that the principle of the resistant heat sensor is viable and can be used to obtain level informations

  15. Heat pipe cooling system for safer storage of spent fuel in nuclear plant

    International Nuclear Information System (INIS)

    This paper proposes completely passive cooling system utilizing heat pipe thermal diode character and natural air convection cooling of condenser, for cooling spent fuel pool. Detail analysis of various heat pipe design cases to determine the best design concept in terms of cooling power, construction and cost has been presented. The best design when considering thermal safety margin and cost is the heat pipe cooling system with capacity of 0.9 MW, 1,662 heat pipe modules. For this design case, water temperature will reach to peak 68degC after 75 hours, and then it will saturate at 50degC after 2,000 hours. The proposed heat pipe systems can be operated completely passive which will provide safer operational environment to nuclear power plants. (author)

  16. Direct Heat-Flux Measurement System (MDF) for Solar central Receiver Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Ballestrin, J.

    2001-07-01

    A direct flux measurement system, MDF, has been designed, constructed and mounted on top of the SSPS-CRS tower at the Plataforma Solar de Almeria (PSA) in addition to an indirect flux measurement system based on a CCD camera. It's one of the main future objectives to compare systematically both measurements of the concentrated solar power, increasing in this way the confidence in the estimate of this quantity. Today everything is prepared to perform the direct flux measurement on the aperture of solar receivers: calorimeter array, data acquisition system and software. the geometry of the receiver determines the operation and analysis procedures to obtain the indecent power onto the defined area. The study of previous experiences with direct flux measurement systems ha been useful to define a new simpler and more accurate system. A description of each component of the MDF system is included, focusing on the heat-flux sensors or calorimeters, which enables these measurements to be done in a few seconds without water-cooling. The incident solar power and the spatial flux distribution on the aperture of the volumetric receiver Hitrec II are supplied by the above-mentioned MDF system. The first results obtained during the evaluation of this solar receiver are presented including a sunrise-sunset test. All these measurements have been concentrated in one coefficient that describes the global behavior of the Solar Power Plant. (Author) 18 refs.

  17. Direct Heat-Flux Measurement System (MDF) for Solar Central Receiver Evaluation

    International Nuclear Information System (INIS)

    A direct flux measurement system, MDF, has been designed, constructed and mounted on top of the SSPSCRS tower at the Plataforma Solar de Almeria (PSA) in addition to an indirect flux measurement system based on a CCD camera. It's one of the main future objectives to compare systematically both measurements of the concentrated solar power, increasing in this way the confidence in the estimate of this quantity. Today everything is prepared to perform the direct flux measurement on the aperture of solar receivers: calorimeter array, data acquisition system and software. The geometry of the receiver determines the operation and analysis procedures to obtain the incident power onto the defined area. The study of previous experiences with direct flux measurement systems has been useful to define a new, simpler and more accurate system. A description of each component of the MDF system is included, focusing on the heat-flux sensors or calorimeters, which enables these measurements to be done in a few seconds without water-cooling. The incident solar power and the spatial flux distribution on the aperture of the volumetric receiver Hitrec II are supplied by the above-mentioned MDF system. The first results obtained during the evaluation of this solar receiver are presented including a sunrise-sunset test. AU these measurements have been concentrated in one coefficient that describes the global behavior of the Solar Power Plant. (Author) 18 refs

  18. The relative contribution of waste heat from power plants to global warming

    International Nuclear Information System (INIS)

    Evidence on global climate change, being caused primarily by rising levels of greenhouse gases in the atmosphere, is perceived as fairly conclusive. It is generally attributed to the enhanced greenhouse effect, resulting from higher levels of trapped heat radiation by increasing atmospheric concentrations of gases such as CO2 (carbon dioxide). Much of these gases originate from power plants and fossil fuel combustion. However, the fate of vast amounts of waste heat rejected into the environment has evaded serious scholarly research. While 1 kWh electricity generation in a typical condensing coal-fired power plant emits around 1 kg of CO2, it also puts about 2 kWh energy into the environment as low grade heat. For nuclear (fission) electricity the waste heat release per kWh is somewhat higher despite much lower CO2 releases. This paper evaluates the impact of waste heat rejection combined with CO2 emissions using Finland and California as case examples. The immediate effects of waste heat release from power production and radiative forcing by CO2 are shown to be similar. However, the long-term (hundred years) global warming by CO2-caused radiative forcing is about twenty-five times stronger than the immediate effects, being responsible for around 92% of the heat-up caused by electricity production.

  19. Roles of Protein Synthesis Elongation Factor EF-Tu in Heat Tolerance in Plants

    Directory of Open Access Journals (Sweden)

    Jianming Fu

    2012-01-01

    Full Text Available EF-Tu proteins of plastids, mitochondria, and the cytosolic counterpart EF-1α in plants, as well as EF-Tu proteins of bacteria, are highly conserved and multifunctional. The functions of EF-Tu include transporting the aminoacyl-tRNA complex to the A site of the ribosome during protein biosynthesis; chaperone activity in protecting other proteins from aggregation caused by environmental stresses, facilitating renaturation of proteins when conditions return to normal; displaying a protein disulfide isomerase activity; participating in the degradation of N-terminally blocked proteins by the proteasome; eliciting innate immunity and triggering resistance to pathogenic bacteria in plants; participating in transcription when an E. coli host is infected with phages. EF-Tu genes are upregulated by abiotic stresses in plants, and EF-Tu plays important role in stress responses. Expression of a plant EF-Tu gene confers heat tolerance in E. coli, maize knock-out EF-Tu null mutants are heat susceptible, and over-expression of an EF-Tu gene improves heat tolerance in crop plants. This review paper summarizes the current knowledge of EF-Tu proteins in stress responses in plants and progress on application of EF-Tu for developing crop varieties tolerant to abiotic stresses, such as high temperatures.

  20. Examination of the influence of water-heated central heating systems on the levels of radon and radon progeny in the workplace

    International Nuclear Information System (INIS)

    A series of continuous real-time radon and progeny measurements, together with passive etched-track detector measurements returning average values, were undertaken in commercial premises in Northamptonshire. Detailed measurements over several months in two separate buildings show that the level of both radon and progeny are determined to a major extent by the influence of the operation and timing of the central heating systems in place. Both buildings studied are similar in construction to many single-storey domestic properties. The operative heating system reduced the radon and progeny levels relative to the non-operating mode by over 40% during the heating period of a normal working day. The variation in temperature during this time was generally less than 3 deg. C, indicative of a heat retentive building. Because the equilibrium (F) fraction is reduced during the heating period, the reductions in radon and progeny are not uniform. In the workplaces studied, the work-cycle was normally limited to 0900-1700 hours Monday to Friday, the period when the lowest values were recorded. Average daily values would therefore overstate by more than 50% the maximum potential dose during normal attendance hours. The corollary is that living under similar circumstances in domestic environments, the operation and timing of this type of heating regime may well result in higher exposure in the home than at work

  1. Long-term performance of central heat pumps in Slovenian homes

    OpenAIRE

    Marčič, Milan

    2012-01-01

    Due to limited availability of natural resources exploited for heating and in order to reduce the environmental impact, people should strive to use renewable energy sources. Heat pumps allow the conversion of ambient heat, available in almost unlimited quantities, to heating energy. The paper describes an energy-saving house provided with good thermal insulation and heated by an air-to-water split-type heat pump. The condenser is located in the attic and the evaporator in the boiler room of t...

  2. Central receiver solar thermal power system, Phase 1. Pilot plant cost and commercial plant cost and performance preliminary design report. [150 MW commercial tower focus plant and 10 MW pilot plant

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-01-01

    Detailed cost and performance data for the 10 MWe Pilot Plant and the 150 MWe Commercial Plant are given. The Commercial Plant consists of 15 integrated collector - receiver modules. Each module contains 1325 heliostats and an internally mounted steam-generating receiver on a steel tower with an aperture height of 90 M. The Pilot Plant consists of one full-scale collector - receiver module. The two-stage sensible heat storage system utilizes a heat transfer salt medium and a hydrocarbon oil storage medium. The electric power generation system uses a conventional steam turbine-generator. The Pilot Plant is one module of the Commercial Plant, providing for one-to-one scaling in the most critical areas. (WHK)

  3. Design optimization of a polygeneration plant producing power, heat, and lignocellulosic ethanol

    International Nuclear Information System (INIS)

    Highlights: • A polygeneration plant producing power, heat, and lignocellulosic ethanol is modeled. • The plant design is optimized to minimize specific ethanol production cost. • An exergy analysis of the ethanol production is conducted. • A diseconomy-of-scale trend applies for the ethanol production in the polygeneration plant. - Abstract: A promising way to increase the energy efficiency and reduce costs of biofuel production is to integrate it with heat and power production in polygeneration plants. This study treats the retrofitting of a Danish combined heat and power plant by integrating lignocellulosic ethanol production based on wheat straw with the aim of minimizing specific ethanol production cost. Previously developed and validated models of the facilities are applied in the attempt to solve the design optimization problem. Straw processing capacities in the range of 5–12 kg/s are considered, while plant operation is optimized over the year with respect to maximal income and with the limitations that the reference hourly district heating production has to be met while reference hourly power export cannot be exceeded. The results suggest that the specific ethanol production cost increased continuously from 0.958 Euro/L at a straw processing capacity of 5 kg/s to 1.113 Euro/L at a capacity of 12 kg/s, indicating that diseconomies-of-scale applies for the suggested ethanol production scheme. A thermodynamic evaluation further discloses that the average yearly exergy efficiency decreases continuously with increasing ethanol production capacity, ranging from 0.746 for 5 kg/s to 0.696 for 12 kg/s. This trend results from operating constraints that induce expensive operation patterns in periods of high district heating loads or shut-down periods for the combined heat and power plant. A sensitivity analysis indicates that the found optimum is indifferent to major variations in fossil fuel prices. The results question the efficiency of the suggested

  4. Standardized interface for district heating centrals in one-family houses; Standardiserat graenssnitt foer fjaerrvaermecentraler i smaahus

    Energy Technology Data Exchange (ETDEWEB)

    Petersson, Stefan [FVB Sverige AB, Vaesteraas (Sweden)

    2005-07-01

    The cost of supplying small houses with district heating is high. Cost effective solutions are therefore important for reasonable economy in small house areas. One thing that, in the long run, can lead to lower costs is a standardized interface between the district heating central and the surrounding systems. Today, manufacturers of district heating centrals have individual solutions for their own models. There are several advantages with a standardized interface. The aim of this project has been to put together today's solutions of the manufacturers and their view on standardizing the interface. Other actors, like suppliers of district heating, manufacturers of small houses, designers of the house internal heating and domestic water system and the Swedish Heat Pump Association have given their point of view. The cost of the district heating central is down to a level that the line of business wanted to reach, but the installation cost can probably be lower. If standardizing means a simplified installation procedure and the line of business is not observant when the purchasing are made, it's likely that the installers profit increase instead of decreased costs for the customer. Negotiated times for installations are to be renegotiated if simplified solutions replace older methods. Today, the interface of the district heating central models are fairly like each other, except for the manufacturer 'Tau District Heating AB' who has a much more compact model. Most of the models have 'fence solutions' that makes it possible to connect the central from above or below. Some models are able to turn. Manufacturers have not exactly the same solution, which probably forces every manufacturer to make some minor changes before a standard can be established. The technical conditions for standardizing the interface are good. How a standard could be designed in detail must be worked out between manufacturers and other actors. The Swedish District

  5. 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.

  6. Physiological, Biochemical, and Molecular Mechanisms of Heat Stress Tolerance in Plants

    Directory of Open Access Journals (Sweden)

    Masayuki Fujita

    2013-05-01

    Full Text Available High temperature (HT stress is a major environmental stress that limits plant growth, metabolism, and productivity worldwide. Plant growth and development involve numerous biochemical reactions that are sensitive to temperature. Plant responses to HT vary with the degree and duration of HT and the plant type. HT is now a major concern for crop production and approaches for sustaining high yields of crop plants under HT stress are important agricultural goals. Plants possess a number of adaptive, avoidance, or acclimation mechanisms to cope with HT situations. In addition, major tolerance mechanisms that employ ion transporters, proteins, osmoprotectants, antioxidants, and other factors involved in signaling cascades and transcriptional control are activated to offset stress-induced biochemical and physiological alterations. Plant survival under HT stress depends on the ability to perceive the HT stimulus, generate and transmit the signal, and initiate appropriate physiological and biochemical changes. HT-induced gene expression and metabolite synthesis also substantially improve tolerance. The physiological and biochemical responses to heat stress are active research areas, and the molecular approaches are being adopted for developing HT tolerance in plants. This article reviews the recent findings on responses, adaptation, and tolerance to HT at the cellular, organellar, and whole plant levels and describes various approaches being taken to enhance thermotolerance in plants.

  7. Expression of E. coli heat-labile enterotoxin B subunit in transgenic tobacco plants

    Institute of Scientific and Technical Information of China (English)

    LIU Hong-li; ZHANG Zheng; LI Wen-sheng; ZHENG Jing; KONG Ling-hong; WANG Yi-li; SI Lü-sheng

    2005-01-01

    Objective: To construct plant transformation vector containing Escherichia coli heat-labile enterotoxin B subunit (LT-B) gene and generate LT-B transgenic tobacco plants. Methods: The LT-B coding sequence was amplified from pMMB68 by PCR, subcloned into middle vector pUCmT and binary vector pBI121 to obtain plant expression vector pBI-LTB, in which LT-B expression was controlled under the Cauliflower mosaic virus (CaMV) 35S promoter. The tobacco plants (Nicotiana tobacum L. Cuttivar Xanthi) were transformed by co-cultivating leaf discs method via Agrobacterium tumefaciens LBA4404 harboring the plant expression vector. The regenerated transgenic tobacco plants were selected by kanamycin and confirmed by PCR, Southern blot, Western blot and ELISA. Results: LT-B gene integrated in the tobacco genomic DNA and were expressed in 9 strains of transgenic tobacco plants. The yield was varied from 3.36-10.56 ng/mg total soluble tobacco leaf protein. Conclusion: The plant binary expression vector pBILTB was constructed successfully, and transgenic LT-B tobacco plants was generated, and confirmed by Southern blot. The protein LT-B expressed by engineered plants was identified by Western blot analysis and had the expected molecular weight of LT-B pentamer protein. This result is an important step close to developing an edible vaccine and supplying a mucasal immunoajuvant, which will contribute to the prevention of mucosa-route evading pathogen.

  8. Optimum Operation of a Thermal Plant with Cogeneration and Heat Pumps

    Directory of Open Access Journals (Sweden)

    M. Sasso

    2001-06-01

    Full Text Available

    In this paper, a complex thermal plant is analyzed. The plant under analysis is basically made up of four gas-fueled engines with heat recovery. Each engine can drive, simultaneously, an electric generator and the compressor of a heat-pump/chiller. The plant is interconnected to the electric utility grid, both to receive additional power and to deliver excess power. In addition, each heat-pump/chiller can be driven electrically, using the electric generator as a motor. For any given amount of power and heat required by the users, a large number of operating conditions are possible. So, the problem arises of selecting, at any given time, the operational mode that involves the lowest instantaneous cost of operating the system. This cost can be regarded as the objective function to be minimized in a typical constrained optimization problem. In the paper, after a short description of the plant, this problem is dealt with. Some examples of the results provided by the optimization algorithm are presented and commented on. The economic savings achievable through an optimized operation are highlighted too.

    • This paper was presented at the ECOS'00 Conference in Enschede, July 5-7, 2000 

  9. 16 CFR 305.12 - Labeling for central air conditioners, heat pumps, and furnaces.

    Science.gov (United States)

    2010-01-01

    ... source as indicated in the appendices to this part. (5) Placement of the labeled product on the scale... heating seasonal performance factors for all heating only heat pumps. (5) Placement of the labeled product... the product in the form of an adhesive label. All adhesive labels should be applied so they can...

  10. Wastewater Land Application Permit LA-000141 Renewal Information for the Central Facilities Area Sewage Treatment Plant

    Energy Technology Data Exchange (ETDEWEB)

    None

    1999-02-01

    On July 25, 1994, the State of ldaho Division of Environmental Quality issued a Wastewater Land Application Permit, #LA-000141-01, for the Central Facilities Area Sewage Treatment Plant. The permit expires August 7, 1999. This report is being submitted with the renewal application and specifically addresses; Wastewater flow; Wastewater characteristics; Impacts to vegetation in irrigation area; Impacts to soil in irrigation area; Evaluation of groundwater monitoring wells for Wastewater Land Application Permit purposes; Summary of trends observed during the 5-year reporting period; and Projection of changes and new processes.

  11. Evaluation and demonstration of decentralized space and water heating versus centralized services for new and rehabilitated multifamily buildings. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Belkus, P. [Foster-Miller, Inc., Waltham, MA (US); Tuluca, A. [Steven Winter Associates, Inc., Norwalk, CT (US)

    1993-06-01

    The general objective of this research was aimed at developing sufficient technical and economic know-how to convince the building and design communities of the appropriateness and energy advantages of decentralized space and water heating for multifamily buildings. Two main goals were established to guide this research. First, the research sought to determine the cost-benefit advantages of decentralized space and water heating versus centralized systems for multifamily applications based on innovative gas piping and appliance technologies. The second goal was to ensure that this information is made available to the design community.

  12. Codigestion of manure and industrial organic waste at centralized biogas plants: process imbalances and limitations

    DEFF Research Database (Denmark)

    Bangsø Nielsen, Henrik; Angelidaki, Irini

    2008-01-01

    The present study focuses on process imbalances in Danish centralized biogas plants treating manure in combination with industrial waste. Collection of process data from various full-scale plants along with a number of interviews showed that imbalances occur frequently. High concentrations of...... conditions) and high fractions of industrial waste in the feedstock was also observed. The process imbalances and suboptimal conditions are mainly allowed to occur due to 1) inadequate knowledge about the waste composition, 2) inadequate knowledge about the waste degradation characteristics, 3) inadequate...... process surveillance, especially with regard to volatile fatty acids, and 4) insufficient pre-storage capacity causing inexpedient mixing and hindering exact dosing of the different waste products....

  13. Isolation and identification mould micoflora inhabiting plant leaf litter from Mount Lawu, Surakarta, Central Java

    Directory of Open Access Journals (Sweden)

    MUHAMMAD ILYAS

    2007-04-01

    Full Text Available A study on isolation and identification mould inhabiting plant leaf litter had been conducted. The objective of the study was to isolate and identify mould inhabiting plant leaf litter from Mount Lawu, Surakarta, Central Java. The mould isolation was based on washing and filtering with membrane isolation method. The result showed that 39 moulds generas with 55 species varians, one group identified in class level, and three groups of unidentified mould isolates had been isolated. Taxas distributions showed that there were endophyte and phytopatogen mould isolates had been isolated such as Fusarium, Pestalotiopsis, Phoma, and Coelomycetes. However, typical soil taxa and common saprobic fungi such as Aspergillus, Cunninghamella, Mucor, Paecilomyces, Penicillium, Rhizopus, and Trichoderma remain dominated the resulted isolates.

  14. Study of flue gas condensing for biofuel fired heat and power plants; Studie av roekgaskondensering foer biobraensleeldade kraftvaermeanlaeggningar

    Energy Technology Data Exchange (ETDEWEB)

    Axby, Fredrik; Gustafsson, J.O.; Nystroem, Johan; Johansson, Kent

    2000-11-01

    This report considers questions regarding flue gas condensing plants connected to bio-fuelled heat and power plants. The report consists of two parts, one where nine existing plants are described regarding technical issues and regarding the experience from the different plants. Part two is a theoretical study where heat balance calculations are made to show the technical and economical performance in different plant configurations and operating conditions. Initially the different parts in the flue gas condensing plant are described. Tube, plate and scrubber condensers are described briefly. The different types of humidifiers are also described, rotor, cross-stream plate heat exchanger and scrubber. Nine flue gas-condensing plants have been visited. The plants where chosen considering it should be bio-fuel fired plant primarily heat and power plants. Furthermore we tried to get a good dissemination considering plant configuration, supplier, geographical position, operating situation and plant size. The description of the different plants focuses on the flue gas condenser and the belonging components. The fuel, flue gas and condensate composition is described as well as which materials are used in the different parts of the plant. The experience from operating the plants and the reasons of why they decided to chose the actual condenser supplier are reported.

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

    Directory of Open Access Journals (Sweden)

    Andreas Poullikkas

    2012-01-01

    Full Text Available 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.

  16. 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.

  17. Rehabilitation of heat exchange equipment a key to power plant life extension and performance improvement

    International Nuclear Information System (INIS)

    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)

  18. Synthesis of the low molecular weight heat shock proteins in plants

    International Nuclear Information System (INIS)

    Heat shock of living tissue induces the synthesis of a unique group of proteins, the heat shock proteins. In plants, the major group of heat shock proteins has a molecular mass of 15 to 25 kilodaltons. Accumulation to these proteins to stainable levels has been reported in only a few species. To examine accumulation of the low molecular weight heat shock proteins in a broader range of species, two-dimensional electrophoresis was used to resolve total protein from the following species: soybean (Glycine max L. Merr., var Wayne), pea (Pisum sativum L., var Early Alaska), sunflower (Helianthus annuus L.), wheat (Triticum asetivum L.), rice (Oryza sativa L., cv IR-36), maize (Zea mays L.), pearl millet (Pennisetum americanum L. Leeke, line 23DB), and Panicum miliaceum L. When identified by both silver staining and incorporation of radiolabel, a diverse array of low molecular weight heat shock proteins was synthesized in each of these species. These proteins accumulated to significant levels after three hours of heat shock but exhibited considerable heterogeneity in isoelectric point, molecular weight, stainability, and radiolabel incorporation. Although most appeared to be synthesized only during heat shock, some were detectable at low levels in control tissue. Compared to the monocots, a higher proportion of low molecular weight heat shock proteins was detectable in control tissues from dicots

  19. Agave salmiana Plant Communities in Central Mexico as Affected by Commercial Use

    Science.gov (United States)

    Martínez Salvador, Martin; Mata-González, Ricardo; Morales Nieto, Carlos; Valdez-Cepeda, Ricardo

    2012-01-01

    Agave salmiana is a native plant species harvested for the commercial production of mezcal ( Agave spirits) in the highlands of central Mexico. The objective of this study was to identify vegetation changes in natural communities where A. salmiana has been differentially harvested for commercial purposes. Three plant community categories were identified in the state of Zacatecas based on their history of A. salmiana utilization: short (less than 10 years of use), moderate (about 25 years), and long (60 or more years). Species cover, composition, and density were evaluated in field surveys by use category. A gradient of vegetation structure of the communities parallels the duration of A. salmiana use. A. salmiana density was greatest (3,125 plants ha-1) in the short-use areas and less (892 plants ha-1) in the moderate-use areas, associated with markedly greater density of shrubs (200%) and Opuntia spp. (50%) in moderate-use areas. The main shrubs were Larrea tridentata, Mimosa biuncifera, Jatropha dioica and Buddleia scordioides while the main Opuntia species were Opuntia leucotricha and Opuntia robusta. A. salmiana density was least (652 plants ha-1) in the long-use areas where shrubs were less abundant but Opuntia spp. density was 25% higher than in moderate-use areas. We suggest that shrubs may increase with moderate use creating an intermediate successional stage that facilitates the establishment of Opuntia spp. Long-term Agave use is generating new plant communities dominated by Opuntia spp. (nopaleras) as a replacement of the original communities dominated by A. salmiana (magueyeras).

  20. Equilibrium temperature as a parameter for estimating the net heat-flux at the air-sea interface in the central red-sea

    OpenAIRE

    Ahmad, F; Sultan, Sar

    1994-01-01

    The net rate of heat exchange at the water surface in the central Red Sea is calculated with reference to the equilibrium temperature and the thermal exchange coefficient, both of which depend on meteorological variables. The monthly means of this exchange agree well with the values computed on the basis of heat balance processes which include sensible, evaporative and radiative heat fluxes.

  1. A Model for Optimization and Analysis of Energy Flexible Boiler Plants for Building Heating Purposes

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, J.R.

    1996-05-01

    This doctoral thesis presents a model for optimization and analysis of boiler plants. The model optimizes a boiler plant with respect to the annual total costs or with respect to energy consumption. The optimum solution is identified for a given number of energy carriers and defined characteristics of the heat production units. The number of heat production units and the capacity of units related to each energy carrier or the capacity of units related to the same energy carrier can be found. For a problem comprising large variation during a defined analysis period the model gives the operating costs and energy consumption to be used in an extended optimization. The model can be used to analyse the consequences with respect to costs and energy consumption due to capacity margins and shifts in the boundary conditions. The model is based on a search approach comprising an operational simulator. The simulator is based on a marginal cost method and dynamic programming. The simulation is performed on an hourly basis. A general boiler characteristic representation is maintained by linear energy or cost functions. The heat pump characteristics are represented by tabulated performance and efficiency as function of state and nominal aggregate capacities. The simulation procedure requires a heat load profile on an hourly basis. The problem of the presence of capacity margins in boiler plants is studied for selected cases. The single-boiler, oil-fired plant is very sensitive to the magnitude of the losses present during burner off-time. For a plant comprising two oil-fired burners, the impact of a capacity margin can be dampened by the selected capacity configuration. The present incentive, in Norway, to install an electric element boiler in an oil-fired boiler plant is analysed. 77 refs., 74 figs., 12 tabs.

  2. Record-breaking 2015 heat waves in Central Europe: how to view them in/nthe climate change context?

    Czech Academy of Sciences Publication Activity Database

    Lhotka, Ondřej; Plavcová, Eva; Kyselý, Jan

    Göttingen: European Geosciences Union, 2016. EGU2016-7126-1. ISSN 1607-7962. [EGU General Assembly 2016. 17.04.2016-22.04.2016, Vienna] Institutional support: RVO:68378289 Keywords : heat waves * climate change scenarios * Central Europe Subject RIV: DG - Athmosphere Sciences, Meteorology; DG - Athmosphere Sciences, Meteorology (UEK-B) http://meetingorganizer.copernicus.org/EGU2016/EGU2016-7126-1.pdf

  3. Development of objective air-mass classifications for studies of heat-related mortality in central Europe and east Asia

    Czech Academy of Sciences Publication Activity Database

    Kyselý, Jan; Kim, J.; Huth, Radan; Choi, B. C.

    Christchurch : Modelling and Simulation Society of Australia and New Zealand, 2007 - (Oxley, L.; Kulasiri, D.), s. 2875-2881 ISBN 978-0-9758400-4-7. [International Congress on Modelling and Simulation. Christchurch (NZ), 10.12.2007-13.12.2007] R&D Projects: GA ČR GC205/07/J044 Institutional research plan: CEZ:AV0Z30420517 Keywords : biometeorology * human mortality * heat stress * air mass classifications * central Europe * east Asia Subject RIV: DG - Athmosphere Sciences, Meteorology

  4. Investigation of thermal energy transport from an anisotropic central heating element to the adjacent channels: A multipoint flux approximation

    International Nuclear Information System (INIS)

    Highlights: • The multipoint flux method is used to solve the problem of heat transfer in anisotropic medium. • The anisotropy results in skewness of the temperature field. • This makes the heat flux to the two channels asymmetric. • The temperature profiles of the coolant in the two channels becomes also different. - Abstract: The problem of heat transfer from a central heating element pressed between two clad plates to cooling channels adjacent and outboard of the plates is investigated numerically. The aim of this work is to highlight the role of thermal conductivity anisotropy of the heating element and/or the encompassing plates on thermal energy transport to the fluid passing through the two channels. When the medium is anisotropic with respect to thermal conductivity; energy transport to the neighboring channels is no longer symmetric. This asymmetry in energy fluxes influence heat transfer to the coolant resulting in different patterns of temperature fields. In particular, it is found that the temperature fields are skewed towards the principal direction of anisotropy. In addition, the heat flux distributions along the edges of the heating element are also different as a manifestation of thermal conductivity anisotropy. Furthermore, the peak temperature at the channel walls change location and magnitude depending on the principal direction of anisotropy. Based on scaling arguments, it is found that, the ratio of width to the height of the heating system is a key parameter which can suggest when one may ignore the effect of the cross-diagonal terms of the full conductivity tensor. To account for anisotropy in thermal conductivity, the method of multipoint flux approximation (MPFA) is employed. Using this technique, it is possible to find a finite difference stencil which can handle full thermal conductivity tensor and in the same time enjoys the simplicity of finite difference approximation. Although the finite difference stencil based on MPFA is

  5. Air pollution prognosis during reorganization of Visaginas heating structure after closing the Ignalina Nuclear Power Plant

    International Nuclear Information System (INIS)

    Air pollution prognosis after reorganization of the Visaginas heating structure in the case of closing the Ignalina Nuclear Power Plant has been made. If heavy fuel, oil with 3% sulphur content, and indigenous incinerable waste would be used as fuel in the built boilers houses, the maximal permissible concentrations of sulphur dioxide and hydrogen chlorine in the smoke would be exceeded. During use of heavy fuel (oil with 1% sulphur content) without smoke desulphurization, the third variant of heat and steam surplus would be best from the ecological point of view. In this case the heat for Visaginas would be produced in the current reserve boiler house and the heat and steam for the closed INPP would be produced in the boiler house located in the INPP territory. The optimum height and diameter of chimneys for both boiler houses would be 90 and 4.2 m, respectively. (author)

  6. Feasibility study for the provision of a reliable heat source for Ignalina nuclear power plant and Visaginas, and the modernisation of Visaginas district heating system. Final report

    International Nuclear Information System (INIS)

    In October 1999, the National Energy Strategy was approved by the Lithuanian Parliament. The National Energy Strategy included the decision to close Unit-1 of INPP before 2005. Later is has been decided to close Unit 2 before the end of 2009 as well. The closure and decommissioning will have heavy impact on the heat supply for the city of Visaginas. Unit 1 and Unit 2 of INPP supplies hot water and steam to INPP for process purposes and for space heating of residential and commercial buildings. When Unit 1 is permanently shut down, reliable heat and steam sources independent of the power plants own heat and steam generation facilities are required for safety reasons in the event of shutdown of the remaining unit for maintenance or in an emergency. These steam and heat sources must be operational before single unit operation is envisaged. Provision of a reliable independent heat and steam source is therefore urgent. After both reactors are shut down permanently, a steam source will be needed at the plant for radioactive waste storage and disposal. Heat and hot tap water will also be needed for the premises during decommissioning. The following measures are recommended: 1. New steam boiler plant at P2, 2. New heat only boiler station at P1, 3. Rehabilitation of existing hot water boilers at P1, 4. Rehabilitation of heat transmission pipeline from P1 to INPP, 5. Rehabilitation of heat transmission pipeline from P1 to Visaginas, 6. Rehabilitation of existing installations inside INPP. (ba)

  7. Central heating in Norway. A study of the market trends for the period 2008-2011; Vannbaaren varme i Norge. Et studium av markedsutviklingen i perioden 2008-2011

    Energy Technology Data Exchange (ETDEWEB)

    Haarberg, Karl Johan; Hansen, Eivind; Bjoerneng, Heidi; Vasvik, Truls

    2012-11-01

    Under floor heating distribution buildings gives the flexibility to accept multiple forms of renewable energy, whether from district heating, biomass, solar collectors or heat pumps. Central heating is therefore a joker for a flexible energy. This is why Prognosesenteret commissioned by Enova has conducted a survey on central heating systems aimed at plumbers over a 5-year period. (eb)

  8. 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)

  9. Development of a Two-Phase Capillary Pumped Heat Transport for Spacecraft Central Thermal Bus

    Science.gov (United States)

    Hoang, Triem; Brown, Michael; Baldauff, Robert; Cummings, Sheila

    2003-01-01

    Thermal requirements of future spacecraft and satellites will certainly outgrow the capability of conventional heat pipes in terms of heat transport, heat density, and temperature control. Emerging passive heat transport technologies such as Capillary Pumped Loop (CPL) and Loop Heat Pipe (LHP) have demonstrated in both ground testing and micro-gravity flight experiments that they have the potential to replace heat pipes as primary heat transport devices in next generation thermal control technology. Like heat pipes, CPLs and LHPs are completely passive systems which have no mechanical moving part to wear out or to introduce unwanted vibration to the spacecraft. However, the heat transport capabilities of CPLs and LHPs are at least one order of magnitude higher than those of heat pipes. Despite sharing many operational characteristics. CPLs and LHPs do have differences. CPLs require a lengthy and tedious start-up procedure to prime the wicks before heat is applied to the evaporator plate. Even with the start-up procedure, start-ups are not always successful. LHPs, on the other hand, do not require a wick pre-conditioning process. But the LHP effective thermal conductance is not as high as that of a CPL. Temperature control of a LHP is not easily achieved. A novel concept, which combined a CPL and a LHP into one loop, was proposed to take advantage of selective features of each system without inheriting their shortcomings. The resultant loop was called Advanced Loop Heat Pipe (A-LHP). A proof-of-concept testbed was put together and tested at the Naval Research Laboratory. Test results showed that the A-LHP performed like a CPL without start-up problems associated with CPLs.

  10. Recent research and development of intermediate heat exchanger for VHTR plant

    International Nuclear Information System (INIS)

    This paper describes recent tests which show progress in design of Intermediate Heat Exchanger (IHX) for high-temperature gas cooled reactor plants developed for process heat application utilizing nuclear thermal energy. As the IHX must have a large heat exchanging capacity, the most important consideration is to design a compact heat exchanger having high efficiency. For the improvement of heat transfer characteristics, tests were performed at Mitsubishi Heavy Industries such as, trial manufacturing, heat transfer characteristic tests and nondestructive inspection tests of finned tubes. Results are as follows; (1) Finned tubes produced by rolling were able to be wound helically by bending machine. (2) Laboratory tests showed this tube had good heat transfer characteristics. (3) There was not much difference between finned tubes and bare tubes for detection of defects by the eddy current tests. (4) A trial assembly using the same scale model showed that the present design is easy to assemble. (5) Automatic orbital welding can be adopted for the welding between tube and tube sheet. As the result of the experiences gained from these successful tests, the design of the IHX has been greatly improved. (author)

  11. Preliminary issues associated with the next generation nuclear plant intermediate heat exchanger design

    Science.gov (United States)

    Natesan, K.; Moisseytsev, A.; Majumdar, S.

    2009-07-01

    The Next Generation Nuclear Plant, with emphasis on production of both electricity and hydrogen, involves helium as the coolant and a closed-cycle gas turbine for power generation with a core outlet/gas turbine inlet temperature of 850-950 °C. In this concept, an intermediate heat exchanger is used to transfer the heat from primary helium from the core to the secondary fluid, which can be helium, a nitrogen/helium mixture, or a molten salt. This paper assesses the issues pertaining to shell-and-tube and compact heat exchangers. A detailed thermal-hydraulic analysis was performed to calculate heat transfer, temperature distribution, and pressure drop inside both printed circuit and shell-and-tube heat exchangers. The analysis included evaluation of the role of key process parameters, geometrical factors in heat exchanger designs, and material properties of structural alloys. Calculations were performed for helium-to-helium, helium-to-helium/nitrogen, and helium-to-salt heat exchangers.

  12. Theoretical Design of a Thermosyphon for Efficient Process Heat Removal from Next Generation Nuclear Plant (NGNP) for Production of Hydrogen

    International Nuclear Information System (INIS)

    The work reported here is the preliminary analysis of two-phase Thermosyphon heat transfer performance with various alkali metals. Thermosyphon is a device for transporting heat from one point to another with quite extraordinary properties. Heat transport occurs via evaporation and condensation, and the heat transport fluid is re-circulated by gravitational force. With this mode of heat transfer, the thermosyphon has the capability to transport heat at high rates over appreciable distances, virtually isothermally and without any requirement for external pumping devices. For process heat, intermediate heat exchangers (IHX) are required to transfer heat from the NGNP to the hydrogen plant in the most efficient way possible. The production of power at higher efficiency using Brayton Cycle, and hydrogen production requires both heat at higher temperatures (up to 1000 C) and high effectiveness compact heat exchangers to transfer heat to either the power or process cycle. The purpose for selecting a compact heat exchanger is to maximize the heat transfer surface area per volume of heat exchanger; this has the benefit of reducing heat exchanger size and heat losses. The IHX design requirements are governed by the allowable temperature drop between the outlet of the NGNP (900 C, based on the current capabilities of NGNP), and the temperatures in the hydrogen production plant. Spiral Heat Exchangers (SHE's) have superior heat transfer characteristics, and are less susceptible to fouling. Further, heat losses to surroundings are minimized because of its compact configuration. SHEs have never been examined for phase-change heat transfer applications. The research presented provides useful information for thermosyphon design and Spiral Heat Exchanger

  13. Cold local heating. Agrothermal heat supply of an ecovillage; Kalt Nahwaerme. Agrothermische Waermeversorgung einer Plusenergiesiedlung

    Energy Technology Data Exchange (ETDEWEB)

    Pietruschka, Dirk [Hochschule fuer Technik Stuttgart (Germany). Forschungszentrum fuer Nachhaltige Energietechnik; Kluge, Juergen [Doppelacker GmbH, Petershagen-Eggersdorf (Germany)

    2013-03-01

    An ecovillage with highly efficient residential buildings is arisen in the Swabian community Wuestenrot. The power generation in these residential buildings by means of photovoltaic power plants is greater than the energy consumption. Decentralized heat plants supply thermal energy for the space heating and industrial waste. Central agrothermal collectors provide the necessary low-temperature heat for the effective operation of heat pumps over a so-called cold heat grid.

  14. Seawater desalination plant using nuclear heating reactor coupled with MED process

    International Nuclear Information System (INIS)

    A small size plant for seawater desalination using nuclear heating reactor coupled with MED process was developed by the Institute of Nuclear Energy Technology, Tsinghua University, China. this seawater desalination plant was designed to supply potable water demand to some coastal location or island where both fresh water and energy source are severely lacking. It is also recommended as a demonstration and training facility for seawater desalination using nuclear energy. The design of small size of seawater desalination plant couples two proven technologies: Nuclear Heating Reactor (NHR) and Multi-Effect Destination (MED) process. The NHR design possesses intrinsic and passive safety features, which was demonstrated by the experiences of the project NHR-5. the intermediate circuit and steam circuit were designed as the safety barriers between the NHR reactor and MED desalination system. Within 10-200 MWt of the power range of the heating reactor, the desalination plant could provide 8000 to 150,000 m3/d of high quality potable water. The design concept and parameters, safety features and coupling scheme are presented

  15. Drought versus heat: What's the major constraint on Mediterranean green roof plants?

    Science.gov (United States)

    Savi, Tadeja; Dal Borgo, Anna; Love, Veronica L; Andri, Sergio; Tretiach, Mauro; Nardini, Andrea

    2016-10-01

    Green roofs are gaining momentum in the arid and semi-arid regions due to their multiple benefits as compared with conventional roofs. One of the most critical steps in green roof installation is the selection of drought and heat tolerant species that can thrive under extreme microclimate conditions. We monitored the water status, growth and survival of 11 drought-adapted shrub species grown on shallow green roof modules (10 and 13cm deep substrate) and analyzed traits enabling plants to cope with drought (symplastic and apoplastic resistance) and heat stress (root membrane stability). The physiological traits conferring efficiency/safety to the water transport system under severe drought influenced plant water status and represent good predictors of both plant water use and growth rates over green roofs. Moreover, our data suggest that high substrate temperature represents a stress factor affecting plant survival to a larger extent than drought per se. In fact, the major cause influencing seedling survival on shallow substrates was the species-specific root resistance to heat, a single and easy measurable trait that should be integrated into the methodological framework for screening and selection of suitable shrub species for roof greening in the Mediterranean. PMID:27239718

  16. A small floating seawater desalination plant using a nuclear heating reactor coupled with the MED process

    International Nuclear Information System (INIS)

    A small floating seawater desalination plant using a nuclear heating reactor coupled with a multi-effect distillation (MED) process was designed by the Institute of Nuclear Energy Technology, Tsinghua University of China. It was intended to supply potable water to remove coastal areas or islands where both fresh water and energy are severely lacking, and also to serve as a demonstration and training facility. The design of a small floating plant coupled two proven technologies in the cogeneration mode: a nuclear heating reactor (NHR-10), with inherent, passive safety features based on NHR-5 experience, and a low temperature MED process. The secondary loop was designed as a safety barrier between the primary loop and the steam loop. With a 10 MW(th) heating reactor, the floating plant could provide 4,000 m3/d of potable water and 750 kW of electricity. The design concept and parameters, safety features, coupling scheme and floating plant layout are presented in the paper. (author). 3 refs, 4 figs, 3 tabs

  17. Seawater desalination plant using nuclear heating reactor coupled with MED process

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A small size plant for seawater desalination using nuclear heating reactor coupled with MED process was developed by the Institute of Nuclear Energy Technology, Tsinghua University, China. This seawater desalination plant was designed to supply potable water demand to some coastal location or island where both fresh water and energy source are severely lacking. It is also recommended as a demonstration and training facility for seawater desalination using nuclear energy. The design of small size of seawater desalination plant couples two proven technologies: Nuclear Heating Reactor (NHR) and Multi-Effect Destination (MED) process. The NHR design possesses intrinsic and passive safety features, which was demonstrated by the experiences of the project NHR-5. The intermediate circuit and steam circuit were designed as the safety barriers between the NHR reactor and MED desalination system. Within 10~200 MWt of the power range of the heating reactor, the desalination plant could provide 8000 to 150,000 m3/d of high quality potable water. The design concept and parameters, safety features and coupling scheme are presented.

  18. Design and analysis of a cogeneration plant using heat recovery of a cement factory

    Directory of Open Access Journals (Sweden)

    G.V. Pradeep Varma

    2015-03-01

    Full Text Available There is a more potential in a cement factory for electric power generation using waste heat recovery compared to the other industries. A case study has been done at a cement factory having two units, 1600 TPD and 5500 TPD, identified three waste heat rejections at 176 °C, 330 °C and 420 °C and designed a suitable power plant configuration. In this work, an attempt has been made to quantify the power generation capacity with plant analysis. It has been resulted that 12.5 MW of power can be produced with the available heat recovery against a cement factory demand of 15 MW. The available process heat for cement production and power generation has been estimated at a capacity range from 5000 to 9000 TPD. The analysis recommended a low steam pressure for power generation at above said heat recovery gas temperature.

  19. Optimal placement of combined heat and power scheme (cogeneration): application to an ethylbenzene plant

    International Nuclear Information System (INIS)

    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)

  20. Exergy analysis of a combined heat and power plant with integrated lignocellulosic ethanol production

    International Nuclear Information System (INIS)

    Highlights: • We model a system where lignocellulosic ethanol production is integrated with a combined heat and power (CHP) plant. • We conduct an exergy analysis for the ethanol production in six different system operation points. • Integrated operation, district heating (DH) production and low CHP loads all increase the exergy efficiency. • Separate operation has the largest negative impact on the exergy efficiency. • Operation is found to have a significant impact on the exergy efficiency of the ethanol production. - Abstract: Lignocellulosic ethanol production is often assumed integrated in polygeneration systems because of its energy intensive nature. The objective of this study is to investigate potential irreversibilities from such integration, and what impact it has on the efficiency of the integrated ethanol production. An exergy analysis is carried out for a modelled polygeneration system in which lignocellulosic ethanol production based on hydrothermal pretreatment is integrated in an existing combined heat and power (CHP) plant. The ethanol facility is driven by steam extracted from the CHP unit when feasible, and a gas boiler is used as back-up when integration is not possible. The system was evaluated according to six operation points that alternate on the following three different operation parameters: Load in the CHP unit, integrated versus separate operation, and inclusion of district heating production in the ethanol facility. The calculated standard exergy efficiency of the ethanol facility varied from 0.564 to 0.855, of which the highest was obtained for integrated operation at reduced CHP load and full district heating production in the ethanol facility, and the lowest for separate operation with zero district heating production in the ethanol facility. The results suggest that the efficiency of integrating lignocellulosic ethanol production in CHP plants is highly dependent on operation, and it is therefore suggested that the

  1. Research on frost formation in air source heat pump at cold-moist conditions in central-south China

    International Nuclear Information System (INIS)

    Highlights: ►A dynamic evaporator model is built up. ► The model involves the ratio of the latent heat to sensible heat of wet air. ►A correlation considering deq is shown below to predict frost accumulation: (Mfrv3)/(Ψdeq2) =((Ta)/(Tw) )0.1((vτ)/(deq) )0.7(l/(deq) )1.378Xa1.228. ►The changing ratio can characterize the early development of system performance. ►The changing ratio can characterize the early development of frost accumulation. -- Abstract: A dynamic evaporator model of air source heat pump (ASHP), considering the ratio of the latent heat to sensible heat of wet air, is presented to analyze the performance of ASHP under frosting. The performance parameters, such as the heating capacity, COP and the outlet temperature of compressor, are simulated with CYCLEPAD. Then a semi-empirical correlation that predicts frost accumulation on the air-side of fin-tube heat exchanger is developed with dimensionless analysis and also modified by a test conducted under cold-moist conditions in winter. In addition, eight influence factors are considered involving the ambient conditions and structures of heat exchanger, whose effects are analyzed as well. Among them, the equivalent diameter of air flow cross-section in fin-tube deq is especially proposed. Lastly, the relationships between the ratio, the performance parameters and the frost accumulation are discussed in this paper, followed by an evaluation of an optimal defrosting time interval to improve the ASHP’s energy efficiency and operational reliability at cold-moist conditions in central-south China.

  2. District heating and cooling systems for communities through power-plant retrofit and distribution network. Volume 2. Tasks 1-3. Final report. [Downtown Toledo steam system

    Energy Technology Data Exchange (ETDEWEB)

    Watt, J.R.; Sommerfield, G.A.

    1979-08-01

    Each of the tasks is described separately: Task 1 - Demonstration Team; Task 2 - Identify Thermal Energy Source(s) and Potential Service Area(s); and Task 3 - Energy Market Analysis. The purpose of the project is to establish and implement measures in the downtown Toledo steam system for conserving scarce fuel supplies through cogeneration, by retrofit of existing base- or intermediate-loaded electric-generating plants to provide for central heating and cooling systems, with the ultimate purpose of applying the results to other communities. For Task 1, Toledo Edison Company has organized a Demonstration Team (Battelle Columbus Laboratories; Stone and Webster; Ohio Dept. of Energy; Public Utilities Commission of Ohio; Toledo Metropolitan Area Council of Governments; and Toledo Edison) that it hopes has the expertise to evaluate the technical, legal, economic, and marketing issues related to the utilization of by-product heat from power generation to supply district heating and cooling services. Task 2 gives a complete technical description of the candidate plant(s), its thermodynamic cycle, role in load dispatch, ownership, and location. It is concluded that the Toledo steam distribution system can be the starting point for developing a new district-heating system to serve an expanding market. Battelle is a member of the team employed as a subcontractor to complete the energy market analysis. The work is summarized in Task 3. (MCW)

  3. Plant biodiversity of beech forests in central-northern Italy: a methodological approach for conservation purposes

    Directory of Open Access Journals (Sweden)

    Marcantonio M

    2012-07-01

    Full Text Available Forests are reckoned essentials as biodiversity reservoirs and carbon sinks. Current threats to forest ecosystems (e.g., climate changes, habitat loss and fragmentation, management changes call for monitoring their biodiversity and preserving their ecological functions. In this study, we characterized plants diversity of five beech forests located in central and north Apennines mountain chain, using results by a probabilistic sampling. In order to achieve our goals, we have considered species richness and abundance, taxonomic distinctness and species composition, using both old and new analytical approaches. Results have shown how: (1 the forest type dominated by Fagus sylvatica is characterized by high complexity, with marked compositional, structural and biodiversity differences; (2 beech forests of Pigelleto di Piancastagnaio and Valle della Corte show the highest plants diversity values. The ecological characteristics of these areas, which sustain high diversity values, are unique and of great conservation interest; (3 the use of species richness as the only diversity measure have not allowed an efficient differentiation between studied areas. Indeed, the use of different indexes and analytical methods is required to detect multiple characteristics of biological diversity, as well as to carry out efficient biodiversity surveys aimed to develop optimal conservation strategies. In the future, we plan to apply the sampling methodology and the analytical approach used in this paper to characterize plants diversity of similar forest types.

  4. Hydrology and plant survival in excavated depressions near an earthen dam in north-central Texas

    Science.gov (United States)

    Williams, Lynde L.; Hudak, Paul F.

    2005-09-01

    This investigation examined plant survival and water sources for small depressions excavated to build an earthen dam and nature trail in north-central Texas, USA. These “inadvertent wetlands” occupy part of an outdoor education facility, overlying alluvial deposits of the Trinity River. A large lake behind the earthen dam strongly influences surface water and groundwater levels in the area. Excavated depressions receive direct precipitation, runoff, and groundwater inputs, losing water by seepage and evapotranspiration. Hydroperiods varied with location and water input: excavations receiving groundwater held water year round; others periodically desiccated. Groundwater-fed depressions had higher salinity; however, the highest average value (1,304 μS/cm) was within the freshwater range. A total of 66 to 75% of emergent and floating wetland species planted in three depressions survived after 2 years. The developing wetlands appear viable under hydrologic conditions typical of the study period. Ultimately, variable hydroperiods among wetlands, and water level fluctuations within individual wetlands, may foster diverse plant-species compositions. Depressed lake levels following long-term drought or increased water demands pose the greatest threat to the developing wetlands.

  5. Chromatin changes in response to drought, salinity, heat, and cold stresses in plants

    Directory of Open Access Journals (Sweden)

    Jong-Myong eKim

    2015-03-01

    Full Text Available Chromatin regulation is essential to regulate genes and genome activities. In plants, the alteration of histone modification and DNA methylation are coordinated with changes in the expression of stress-responsive genes to adapt to environmental changes. Several chromatin regulators have been shown to be involved in the regulation of stress-responsive gene networks under abiotic stress conditions. Specific histone modification sites and the histone modifiers that regulate key stress-responsive genes have been identified by genetic and biochemical approaches, revealing the importance of chromatin regulation in plant stress responses. Recent studies have also suggested that histone modification plays an important role in plant stress memory. In this review, we summarize recent progress on the regulation and alteration of histone modification (acetylation, methylation, phosphorylation, and SUMOylation in response to the abiotic stresses, drought, high-salinity, heat, and cold in plants.

  6. Research on technological assessment for ageing management of reprocessing plant. Assessment of stainless steel heating component

    International Nuclear Information System (INIS)

    The purpose of the research program is to provide review manuals and technical database for Ageing Management Technical Evaluation Reports performed by licensees of spent fuel reprocessing plants in accordance with ordinance on Periodic Safety Review. Research programs have been conducted based on a contract with well-equipped organization since F.Y. 2006. One experimental subjects on ageing phenomena listed below in this program for the technological assessment of TOKAI plant, which have experienced many corrosion problems. TOKAI plant is the pilot plant for reprocessing service commissioned in Dec. 1980 and shifted to R and D in Apr. 2006. - Corrosion of stainless steel components in boiling nitric acid solutions at heating portions -. (author)

  7. Habitat Range of two Alpine Medicinal Plants in a Trans-Himalayan Dry Valley, Central Nepal

    Institute of Scientific and Technical Information of China (English)

    Bharat Babu SHRESTHA; Pramod Kumar JHA

    2009-01-01

    Understanding of the habitat range of threatened Himalayan medicinal plants which are declining in their abundance due to high anthropogenic disturbances is essential for developing conservation strategies and agro-technologies for cultivation. In this communication, we have discussed the habitat range of two alpine medicinal plants, Aconitum naviculare (Briihl) Stapf and Neopierorhiza scrophulariiflora (Pennel) Hong in a trans-Himalayan dry valley of central Nepal, Manang district. They are the most prioritized medicinal plants of the study area in terms of ethnomedicinal uses. A. naviculare occurs on warm and dry south facing slopes between 4090-4650 m asl along with sclerophyllous and thorny alpine scrubs, while N. serophulariiflora is exclusively found on cool and moist north facing slope between 4o0o and 4400 m asl where adequate water is available from snow melt to create a suitable habitat for this wetland dependent species. The soil in rooting zone of the two plants differs significantly in organic carbon (OC), organic matter (OM), total nitrogen (N) and carbon to nitrogen (C/N) ratio. Due to cool and moist condition of N. scrophulariiflora habitat, accumulation of soil OC is higher, but soil N content is lower probably due to slow release from litter, higher leaching loss and greater retention in perennial live biomass of the plant. The C/N ratio of soil is more suitable in A. navuculare habitat than that of N scrophulariiflora for N supply. Warm and sunny site with N rich soft can be suitable for cultivation of A. naviculare, while moist and cool site with organic soil for N. scrophulariiflora. The populations of both the plants are fragmented and small. Due to collection by human and trampling damage by livestock, the population of A. naviculare was found absent in open areas in five of the six sampling sites and it was confined only within the bushes of alpine scrubs. For N. serophulariiflora, high probability of complete receding of small glaciers may

  8. Development of small (10 MW thermal) nuclear plant with lead-bismuth coolant for electricity and heat co-generation, production of fresh water and hydrogen

    International Nuclear Information System (INIS)

    The paper is presented to evaluate the possibilities of developing a small capacity transportable nuclear power and technology plant (SC TNPTP) with lead-bismuth as a coolant intended for electricity and heat supply, production of fresh water and hydrogen. Its basic distinctive features compared to other various small capacity nuclear power plants (SC NPPS) under development are: simplified design; extended life time; safety and reliability; a pumpless scheme of coolant circulation; utilization of a gas turbine facility with a closed circuit; variable production ratios of the electricity, heat and its products such as fresh water and hydrogen. All these features give grounds for a new generation nuclear power and technology plant (NPTP). TNPTP uses a compact desalinator based on a multi-effect distillation process and/or an electrolizer with metal hydrides for hydrogen accumulation. The plant's capacity of 10 MW(thermal) has been chosen based on the economic optimization of the electricity and thermal heat to be supplied for the production of fresh water and hydrogen (even if the operations are simultaneous, i.e., cogenerating) in the isolated regions far remote from the centralized energy supply sources. (author)

  9. 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.

  10. Joint Electricity and Heat Production Possibilities on the Basis of the District Trigeneration Plant

    Directory of Open Access Journals (Sweden)

    Ershov Vadim

    2016-01-01

    Full Text Available Renewable energy has become increasingly important in the last decade due to the limited reserves of fossil fuels and environmental issues related to CO2 emissions. The paper investigates the joint production possibility of electricity and heat in the Tomsk district Stepanovka, using modern trigeneration plant. The analysis was performed based on a comparison of the two alternatives for the area: the use of a diesel power plant (DPP or gas-piston units (GPU on biofuel. Technical and economic indicators for two different systems were calculated to evaluate the projects effectiveness.

  11. Technoeconomic evaluation of trigeneraton plant: Gas turbine performance, absorption cooling and district heating

    OpenAIRE

    Polyzakis, Apostolos

    2006-01-01

    This PhD thesis is a demand led study taking into account changes in ambient conditions and power settings of a tri-generation power plant. Includes an evaluation tool for combined heat, cooling and power generation plant. The thesis is based on an overall technical-economic analysis of the tri-generation system, including: 1. Energy demand analysis and evaluation of actual tri-generation case studies. 2. Modelling of the prime mover (Gas Turbine, GT) 3. Modelling of the abs...

  12. Mass flows of perfluorinated compounds (PFCs) in central wastewater treatment plants of industrial zones in Thailand.

    Science.gov (United States)

    Kunacheva, Chinagarn; Tanaka, Shuhei; Fujii, Shigeo; Boontanon, Suwanna Kitpati; Musirat, Chanatip; Wongwattana, Thana; Shivakoti, Binaya Raj

    2011-04-01

    Perfluorinated compounds (PFCs) are fully fluorinated organic compounds, which have been used in many industrial processes and have been detected in wastewater and sludge from municipal wastewater treatment plants (WWTPs) around the world. This study focused on the occurrences of PFCs and PFCs mass flows in the industrial wastewater treatment plants, which reported to be the important sources of PFCs. Surveys were conducted in central wastewater treatment plant in two industrial zones in Thailand. Samples were collected from influent, aeration tank, secondary clarifier effluent, effluent and sludge. The major purpose of this field study was to identify PFCs occurrences and mass flow during industrial WWTP. Solid-phase extraction (SPE) coupled with HPLC-ESI-MS/MS were used for the analysis. Total 10 PFCs including perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluoropropanoic acid (PFPA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorohexane sulfonate (PFHxS), perfluoronanoic acid (PFNA), perfluordecanoic acid (PFDA), perfluoroundecanoic acid (PFUnA), and perfluorododecanoic acid (PFDoA) were measured to identify their occurrences. PFCs were detected in both liquid and solid phase in most samples. The exceptionally high level of PFCs was detected in the treatment plant of IZ1 and IZ2 ranging between 662-847ngL(-1) and 674-1383ngL(-1), respectively, which greater than PFCs found in most domestic wastewater. Due to PFCs non-biodegradable property, both WWTPs were found ineffective in removing PFCs using activated sludge processes. Bio-accumulation in sludge could be the major removal mechanism of PFCs in the process. The increasing amount of PFCs after activated sludge processes were identified which could be due to the degradation of PFCs precursors. PFCs concentration found in the effluent were very high comparing to those in river water of the area. Industrial activity could be the one of major sources of PFCs

  13. Exergy analysis of a combined heat and power plant with integrated lignocellulosic ethanol production

    DEFF Research Database (Denmark)

    Lythcke-Jørgensen, Christoffer Ernst; Haglind, Fredrik; Clausen, Lasse Røngaard

    2014-01-01

    Lignocellulosic ethanol production is often assumed integrated in polygeneration systems because of its energy intensive nature. The objective of this study is to investigate potential irreversibilities from such integration, and what impact it has on the efficiency of the integrated ethanol...... production. An exergy analysis is carried out for a modelled polygeneration system in which lignocellulosic ethanol production based on hydrothermal pretreatment is integrated in an existing combined heat and power (CHP) plant. The ethanol facility is driven by steam extracted from the CHP unit when feasible...... with zero district heating production in the ethanol facility. The results suggest that the efficiency of integrating lignocellulosic ethanol production in CHP plants is highly dependent on operation, and it is therefore suggested that the expected operation pattern of such polygeneration system is...

  14. An Optimal Control Approach for an Overall Cryogenic Plant Under Pulsed Heat Loads

    CERN Document Server

    Gómez Palacin, Luis; Blanco Viñuela, Enrique; Maekawa, Ryuji; Chalifour, Michel

    2015-01-01

    This work deals with the optimal management of a cryogenic plant composed by parallel refrigeration plants, which provide supercritical helium to pulsed heat loads. First, a data reconciliation approach is proposed to estimate precisely the refrigerator variables necessary to deduce the efficiency of each refrigerator. Second, taking into account these efficiencies, an optimal operation of the system is proposed and studied. Finally, while minimizing the power consumption of the refrigerators, the control system maintains stable operation of the cryoplant under pulsed heat loads. The management of the refrigerators is carried out by an upper control layer, which balances the relative production of cooling power in each refrigerator. In addition, this upper control layer deals with the mitigation of malfunctions and faults in the system. The proposed approach has been validated using a dynamic model of the cryoplant developed with EcosimPro software, based on first principles (mass and energy balances) and the...

  15. An Optimal Control Approach for an Overall Cryogenic Plant Under Pulsed Heat Loads

    Science.gov (United States)

    Palaćın, Luis Gómez; Bradu, Benjamin; Viñuela, Enrique Blanco; Maekawa, Ryuji; Chalifour, Michel

    This work deals with the optimal management of a cryogenic plant composed by parallel refrigeration plants, which provide supercritical helium to pulsed heat loads. First, a data reconciliation approach is proposed to estimate precisely the refrigerator variables necessary to deduce the efficiency of each refrigerator. Second, taking into account these efficiencies, an optimal operation of the system is proposed and studied. Finally, while minimizing the power consumption of the refrigerators, the control system maintains stable operation of the cryoplant under pulsed heat loads. The management of the refrigerators is carried out by an upper control layer, which balances the relative production of cooling power in each refrigerator. In addition, this upper control layer deals with the mitigation of malfunctions and faults in the system. The proposed approach has been validated using a dynamic model of the cryoplant developed with EcosimPro software, based on first principles (mass and energy balances) and thermo-hydraulic equations.

  16. Thermal analysis of the heat recuperator of a combined cycle thermoelectric central; Analisis termico del recuperador de calor de una central termoelectrica de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes, Hernando; Sanchez, I.; Lazcano, L. C.; Ambriz, Juan Jose; Alvarez, M. [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D. F. (Mexico); Gonzalez, O. [Comision Federal de Electricidad, Tula (Mexico)

    1996-12-31

    The thermoelectric centrals of the combined cycle type (Brayton Cycle and Rankine Cycle) present a series of opportunities to increase the efficiency of the combined cycle or of the generated power. This paper shows the methodology for the performance of energy balances in a heat recuperator (H. R.), typically employed in the combined cycle stations operating in Mexico, for the assessment of the energy harnessing in the different sections conforming a H. R. The effect of the installation of evaporative coolers and/or an absorption cooling system at the gas turbine compressor intake on the steam generation in the heat recuperator, is evaluated. This extra generation of steam is quantified for its potential use in the same absorption refrigeration system. From the assessment, it follows up that the steam generation in the H.R. is inversely proportional to the ambient temperature and that, although the increased amount of steam generated can not be harnessed in total by the steam turbine, the remaining fraction is good enough to cover the heat demand for the operation of the refrigeration system. [Espanol] Las centrales termoelectricas del tipo ciclo combinado (ciclo Brayton y ciclo Rankine) presentan un conjunto de oportunidades para incrementar la eficiencia del ciclo combinado o bien la potencia generada. En el presente trabajo se expone la metodologia para realizar los balances de energia en un recuperador de calor (R.C.) tipicamente utilizado en las Centrales de Ciclo Combinado (CCC) que operan en Mexico, para evaluar el aprovechamiento de la energia en las diferentes secciones que conforman un R.C. Se evalua el efecto que tiene la instalacion de enfriadores evaporativos y/o un sistema de enfriamiento por absorcion en la succion del compresor de la turbina de gas sobre la generacion de vapor en el recuperador de calor. Se cuantifica esta generacion extra de vapor para su posible utilizacion en el mismo sistema de refrigeracion por absorcion. De la evaluacion se

  17. Torrefaction of invasive alien plants: Influence of heating rate and other conversion parameters on mass yield and higher heating value.

    Science.gov (United States)

    Mundike, Jhonnah; Collard, François-Xavier; Görgens, Johann F

    2016-06-01

    With the aim of controlling their proliferation, two invasive alien plants, Lantana camara (LC) and Mimosa pigra (MP), both widespread in Africa, were considered for torrefaction for renewable energy applications. Using thermogravimetric analysis, the influence of heating rate (HR: 2.18-19.82°Cmin(-1)) together with variable temperature and hold time on char yield and HHV (in a bomb calorimeter) were determined. Statistically significant effects of HR on HHV with optima at 10.5°Cmin(-1) for LC and 20°Cmin(-1) for MP were obtained. Increases of HHV up to 0.8MJkg(-1) or energy yield greater than 10%, together with a 3-fold reduction in torrefaction conversion time could be achieved by optimisation of HR. Analysis of the torrefaction volatiles by TG-MS showed that not only hemicelluloses, but also lignin conversion, could influence the optimum HR value. PMID:26954309

  18. The production of activated carbon using the equipment of thermal power plants and heating plants

    Science.gov (United States)

    Osintsev, K. V.; Osintsev, V. V.; Dzhundubaev, A. K.; Kim, S. P.; Al'musin, G. T.; Akbaev, T. A.; Bogatkin, V. I.

    2013-08-01

    The production technology of activated carbon using the conventional equipment of the thermal power stations and boiler houses is proposed. The obtained product is directed into the systems of chemical water preparation and water drain of enterprises. The production cycle is invariable when producing the activated carbon by the proposed technology. The fuel consumption and heat losses are considerably reduced when implementing this technology compared with the known analogs of the carbon sorbent. The production efficiency increases if small dust particles are preliminary separated and coal is activated in narrow ranges of fraction sizes.

  19. Investigation of thermal energy transport from an anisotropic central heating element to the adjacent channels: A multipoint flux approximation

    KAUST Repository

    Salama, Amgad

    2015-02-01

    The problem of heat transfer from a central heating element pressed between two clad plates to cooling channels adjacent and outboard of the plates is investigated numerically. The aim of this work is to highlight the role of thermal conductivity anisotropy of the heating element and/or the encompassing plates on thermal energy transport to the fluid passing through the two channels. When the medium is anisotropic with respect to thermal conductivity; energy transport to the neighboring channels is no longer symmetric. This asymmetry in energy fluxes influence heat transfer to the coolant resulting in different patterns of temperature fields. In particular, it is found that the temperature fields are skewed towards the principal direction of anisotropy. In addition, the heat flux distributions along the edges of the heating element are also different as a manifestation of thermal conductivity anisotropy. Furthermore, the peak temperature at the channel walls change location and magnitude depending on the principal direction of anisotropy. Based on scaling arguments, it is found that, the ratio of width to the height of the heating system is a key parameter which can suggest when one may ignore the effect of the cross-diagonal terms of the full conductivity tensor. To account for anisotropy in thermal conductivity, the method of multipoint flux approximation (MPFA) is employed. Using this technique, it is possible to find a finite difference stencil which can handle full thermal conductivity tensor and in the same time enjoys the simplicity of finite difference approximation. Although the finite difference stencil based on MPFA is quite complex, in this work we apply the recently introduced experimenting field approach which construct the global problem automatically.

  20. Role and Regulation of Autophagy in Heat Stress Responses of Tomato Plants

    OpenAIRE

    Jie eZhou; Jian eWang; Jingquan eYu; Zhixiang eChen

    2014-01-01

    As sessile organisms, plants are constantly exposed to a wide spectrum of stress conditions such as high temperature, which causes protein misfolding. Misfolded proteins are highly toxic and must be efficiently removed to reduce cellular proteotoxic stress if restoration of native conformations is unsuccessful. Although selective autophagy is known to function in protein quality control by targeting degradation of misfolded and potentially toxic proteins, its role and regulation in heat st...

  1. Control Optimization through Simulations of Large Scale Solar Plants for Industrial Heat Applications

    OpenAIRE

    Ben Hassine Ilyes, Cotrado Sehgelmeble Mariela, Söll Robert, Pietruschka Dirk

    2015-01-01

    The European FP7 Project InSun; which started in April 2012; aims to demonstrate the reliability and efficiency of three different collector technologies suitable for heat production employed in diverse industrial processes in different climatic regions. These collectors are installed and will be monitored in detail over a period of almost two years. One of the plants is installed at Fleischwaren Berger GmbH located in Sieghartskirchen, Austria, a company which produces meat and sausage p...

  2. Experimental investigations on the transient behaviour of nuclear heat plants with natural convection

    International Nuclear Information System (INIS)

    Apart from the theoretical approach, practical experiments concerning the transient behaviour of the primary loop of reactors with natural coolant convection are necessary in order to evaluate the safety systems of reactors providing heat for industrial and communal consumers. The article presents experiments concerning the transient behaviour of the experimental plant DANTON, which models the reactor AST-500, and gives a preview of further research. (orig.)

  3. Detailed process modeling of a wood gasification combined heat and power plant

    International Nuclear Information System (INIS)

    We provide the first process simulation able to depict a complete life cycle inventory of a biomass gasification combined heat and power (CHP) plant. The model predicts the detailed mass and energy balances, minor compounds emissions (such as NOx, SOx, aromatics, etc.). It is based on a phenomenological approach for dryer, reactors (gasification and combustion) and scrubber modeling. Process units are modeled with Aspen Plus® models completed with dedicated Fortran sub-models when more details are required. The gasifier is a Dual Fluidized Bed (DFB). It is decomposed in three sections, describing the three main mechanisms occurring in the reactor: wood pyrolysis, secondary reactions and char combustion. At the outlet of the gasifier, the complete composition of the syngas is predicted, which includes water, permanent gases, inorganics, particles and tars (phenol, benzene, toluene, styrene, indene, naphthalene, acenaphthylene, anthracene, phenanthrene, pyrene). Simulation results were validated against measurements from a pilot plant and other literature data. A wet conventional syngas cleaning system for gasification plant, including cyclone, catalytic tar cracker, syngas cooler, bag filters, water scrubber and wastewater treatment was considered and modeled. The complexity of tar composition allows a reliable determination of tar dew point. At the outlet of the cleaning system, syngas is burned in gas engines. Gaseous emissions (NOx, SOx, etc.) of the gas engines and the DFB combustor are also handled by the model as well as ashes and liquid waste. The predicted electrical and thermal efficiencies are 27 and 39% respectively. Highlights: ► A new model of a biomass gasification combined heat and power plant is presented. ► The whole gasification process is modelled under Aspen Plus from dryer to gas engine. ► Heat streams are integrated for internal needs and district heating. ► Tar and inorganic compounds are predicted. ► A detailed life cycle inventory

  4. Sequential extraction partitioning of trace and nutrient elements in ashes from biomass firing district heating plants

    Directory of Open Access Journals (Sweden)

    Šyc M.

    2013-04-01

    Full Text Available Four different ashes from three district heating plants firing biomass were studied with the respect to their potential application as soil fertilizers. Major and trace elements content and some important characteristics of the studied ashes are also presented. Five stage sequential extraction procedure was used for the determination of distribution and speciation of As, Ca, Cd, Cr, Cu, K, Mg, Na, Ni, Pb and Zn in studied ash samples.

  5. Sequential Extraction Partitioning of Trace and Nutrient Elements in Ashes from Biomass Firing District Heating Plants

    OpenAIRE

    Šyc M.; Tošnarová M.; Hrma J.; Pohořelý M.; Svoboda K.; Punčochář M.

    2012-01-01

    Four different ashes from three district heating plants firing biomass were studied with the respect to their potential application as soil fertilizers. Major and trace elements content and some important characteristics of the studied ashes are also presented. Five stage sequential extraction procedure was used for the determination of distribution and speciation of As, Ca, Cd, Cr, Cu, K, Mg, Na, Ni, Pb and Zn in studied ash samples.

  6. Screening of the topical anti-inflammatory activity of some Central American plants.

    Science.gov (United States)

    Sosa, S; Balick, M J; Arvigo, R; Esposito, R G; Pizza, C; Altinier, G; Tubaro, Aurelia

    2002-07-01

    Hexane, chloroform and methanol extracts of seven herbal drugs used in the folk medicine of Central America against skin disorders (Aristolochia trilobata leaves and bark, Bursera simaruba bark, Hamelia patens leaves, Piper amalago leaves, and Syngonium podophyllum leaves and bark) were evaluated for their topical anti-inflammatory activity against the Croton oil-induced ear oedema in mice. Most of the extracts induced a dose-dependent oedema reduction. The chloroform extract of almost all the drugs exhibited interesting activities with ID(50) values ranging between 108 and 498 micro g/cm(2), comparable to that of indomethacin (93 micro g/cm(2)). Therefore, the tested plants are promising sources of principles with high anti-inflammatory activity. PMID:12065153

  7. Fuel-oil cogeneration plant for textile Industry. Central de cogeneracion a fueloleo para industria textil

    Energy Technology Data Exchange (ETDEWEB)

    Navarro Larrauri, M.; Diez Hernandez, J.; Villasante Diaz, A. (IDOM, Ingenieria y Consultoria, S.A. (Spain))

    1993-10-01

    Aznar S.A. is a textile factory especially sensitive to electricity distribution failures. They produce the subsequent shut down at the manufacturing process and several hours of maintenance tasks. A cogeneration plant has been installed to provide electricity and thermal energy to the process. Since the location is far from Natural Gas pipelines the system includes fuel-oil as energy source. Annual electricity production will be 23.300 MWh and 6.400 MWh of them will be exported into the grid. Fuel-oil consumption at the heat exchanger is reduced by 47%, but the whole factory consumption increases a 247% due to the high consumption of the engine. This increase is compensated by revenues from selling electricity and electricity savings. These facts, together with maintenance cost saving leads to a pay back time of 3.3. years. (Author)

  8. Preliminary design of the Carrisa Plains solar central receiver power plant. Volume III, Book 3. Appendices. Part 2

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S. K.

    1983-12-31

    The auxiliary heat transport systems of the Carrisa Plains Solar Power Plant (CPSPP) comprise facilities which are used to support plant operation and provide plant safety and maintenance. The facilities are the sodium purification system, argon cover gas system, sodium receiving and filling system, sodium-water reaction product receiving system, and safety and maintenance equipment. The functions of the facilities of the auxiliary system are described. Design requirements are established based on plant operating parameters. Descriptions are given on the system which will be adequate to perform the function and satisfy the requirements. Valve and equipment lists are included in the appendix.

  9. Wastewater recycling and heat reclamation at the Red Lion Central Laundry, Portland, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    Garlick, T.F.; Halverson, M.A.; Ledbetter, M.R.

    1996-09-01

    This report discusses water, energy, and cost savings that can be achieved in a commercial laundry through the use of a wastewater recycling and heat recovery system. Cost savings are achieved through reductions in water use, reduction in sewage charges, reductions in water heating energy, and potential reductions in water treatment chemicals. This report provides an economic analysis of the impact of capital investment, daily consumption, and local utility rates on the payback period.

  10. Solar space and water heating system at Stanford University Central Food Services Building. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-01

    This active hydronic domestic hot water and space heating system was 840 ft/sup 2/ of single-glazed, liquid, flat plate collectors and 1550 gal heat storage tanks. The following are discussed: energy conservation, design philosophy, operation, acceptance testing, performance data, collector selection, bidding, costs, economics, problems, and recommendations. An operation and maintenance manual and as-built drawings are included in appendices. (MHR)

  11. District heat for Bern-West and vicinity from waste heat of the Muehleberg nuclear power plant and biogas from the Teuftal refuse tip

    International Nuclear Information System (INIS)

    At a time when man in industrial countries is creating heavy environmental, especially atmospheric pollution through energy consumption and its side effects, the use of waste heat from existing plants is an exemplary measure of active environmental conservation. West of Bern in Switzerland the Muehleberg nuclear power plant and the Teuftal refuse tip are sources of waste heat which have the potential for supplying large areas of the Bern region with environment compatible heat for space and water heating. Fundamental surveys for this region have shown that a secure and environment oriented heat supply can be realised for at least 20 years. With the proper extension of the supply area the economy of the project could be improved even further. (orig.)

  12. 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.

  13. Performance investigation of a cogeneration plant with the efficient and compact heat recovery system

    KAUST Repository

    Myat, Aung

    2011-10-03

    This paper presents the performance investigation of a cogeneration plant equipped with an efficient waste heat recovery system. The proposed cogeneration system produces four types of useful energy namely: (i) electricity, (ii) steam, (iii) cooling and (iv) dehumidification. The proposed plant comprises a Capstone C30 micro-turbine which generates 24 kW of electricity, a compact and efficient waste heat recovery system and a host of waste heat activated devices namely (i) a steam generator, (ii) an absorption chiller, (iii) an adsorption chiller and (iv) a multi-bed desiccant dehumidifier. The numerical analysis for the host of waste heat recovery system and thermally activated devices using FORTRAN power station linked to powerful IMSL library is performed to investigate the performance of the overall system. A set of experiments, both part load and full load, of micro-turbine is conducted to examine the electricity generation and the exhaust gas temperature. It is observed that energy utilization factor (EUF) could achieve as high as 70% while Fuel Energy Saving Ratio (FESR) is found to be 28%.

  14. Olfactory Response and Host Plant Feeding of the Central American Locust Schistocerca piceifrons piceifrons Walker to Common Plants in a Gregarious Zone.

    Science.gov (United States)

    Poot-Pech, M A; Ruiz-Sánchez, E; Ballina-Gómez, H S; Gamboa-Angulo, M M; Reyes-Ramírez, A

    2016-08-01

    The Central American locust (CAL) Schistocerca piceifrons piceifrons Walker is one of the most harmful plant pests in the Yucatan Peninsula, where an important gregarious zone is located. The olfactory response and host plant acceptance by the CAL have not been studied in detail thus far. In this work, the olfactory response of the CAL to odor of various plant species was evaluated using an olfactometer test system. In addition, the host plant acceptance was assessed by the consumption of leaf area. Results showed that the CAL was highly attracted to odor of Pisonia aculeata. Evaluation of host plant acceptance showed that the CAL fed on Leucaena glauca and Waltheria americana, but not on P. aculeata or Guazuma ulmifolia. Analysis of leaf thickness, and leaf content of nitrogen (N) and carbon (C) showed that the CAL was attracted to plant species with low leaf C content. PMID:26957085

  15. Amaranthus cruentus L. is suitable for cultivation in Central Italy: field evaluation and response to plant densities

    Directory of Open Access Journals (Sweden)

    Paolo Casini

    2014-12-01

    Full Text Available The aim of this study was to determine the possibility of amaranth cultivation in Central Italy and to determine the optimum plant density. Field trials were carried out in 2011 and 2012 under non-irrigated conditions in Tuscany (43° 18’ N, 11° 47’ E. Twelve accessions of two amaranth species (Amaranthus cruentus L. and A. hypochondriacus L. were utilised. Genotypes were evaluated over a two-year period using a RCB design with three replicates. The effects of plant density were investigated in 2012. A with a split-plot design was used, where the A. cruentus accessions (AMES 5148, PI 511719 and PI 643045 constituted the main plots. Plant densities (7.5, 15, 30 and 60 plants m–2 constituted the subplots. Plants were transplanted at the 3-4 true leaf stage. Morphological traits were determined using 5 plants selected from the two central rows of the sampling area. Plots were hand-harvested and cleaned with a mechanical grid with appropriate sieve diameters. A. cruentus was shown to be more suitable to the Central Italy agro-ecological conditions than A. hypochondriacus. The accessions derived from Mexico (PI 477913, PI 576481, PI 643045, PI 643053, and PI 6495079, Guatemala (PI 511719 and Puerto Rico (AMES 5148, had both higher grain yields and a greater stability over the two-year period, with a mean grain production ranging from 2.8 to 3.2 t ha–1. The severe climatic stress in 2012 (high temperatures and aridity, resulted in a 43-60% reduction in seed production compared to that of the previous year. Under these conditions, PI 511719, AMES 26015, AMES 5386, AMES 5148, PI 477913 yielded on average 1.9 t ha–1. Yields of A. hypochondriacus were negligible in both years, probably attributable to greater photoperiod sensitivity, resulting in reduced flowering and delayed maturity. By increasing density up to 60 and 30 plants m–2 for PI 511719 and AMES 5148, respectively, grain production was increased by 55%. As the plant population

  16. Final report on the power production phase of the 10 MW/sub e/ Solar Thermal Central Receiver Pilot Plant

    Energy Technology Data Exchange (ETDEWEB)

    Radosevich, L.G.

    1988-03-01

    This report describes the evaluations of the power production testing of Solar One, the 10 MW/sub e/ Solar Thermal Central Receiver Pilot Plant near Barstow, California. The Pilot Plant, a cooperative project of the US Department of Energy and utility firms led by the Southern California Edison Company, began a three year period of power production operation in August 1984. During this period, plant performance indicators, such as capacity factor, system efficiency, and availability, were studied to assess the operational capability of the Pilot Plant to reliably supply electrical power. Also studied was the long-term performance of such key plant components as the heliostats and the receiver. During the three years of power production, the Pilot Plant showed an improvement in performance. Considerable increases in capacity factor, system efficiency, and availability were achieved. Heliostat operation was reliable, and only small amounts of mirror corrosion were observed. Receiver tube leaks did occur, however, and were the main cause of the plant's unscheduled outages. The Pilot Plant provided valuable lessons which will aid in the design of future solar central receiver plants. 53 refs., 46 figs., 4 tabs.

  17. Paleoclimate influence on early diagenesis of plant triterpenes in the Dajiuhu peatland, central China

    Science.gov (United States)

    Huang, Xianyu; Xue, Jiantao; Wang, Xinxin; Meyers, Philip A.; Huang, Junhua; Xie, Shucheng

    2013-12-01

    Aromatic derivatives of vascular plant triterpenoids are common in recent and ancient sediments, coal, and petroleum. Understanding their early diagenetic alterations and their relation with environmental conditions can facilitate their applications in paleoenvironmental reconstructions. Here we present a high-resolution record of aromatic triterpenes in a Holocene peat core collected in the Dajiuhu peatland, central China. These aromatic triterpenes are derivatives of plant triterpenoids with oleanane, ursane and lupane carbon skeletons and exist in three different structural groups: aromatic des-A-triterpenes, aromatic pentacyclic triterpenes, and C-ring cleaved aromatic triterpenes. Such a high diversity of aromatic triterpenes in a young peat deposit is compelling evidence for rapid microbial mediation of these important degradation pathways during very early diagenesis. Of particular importance is the occurrence of C-ring cleaved aromatic triterpene and aromatic des-A-triterpenes in the Dajiuhu peat samples, which until now have not been identified in recent sediments. The downcore profile shows that the microbial aromatization process of oleanoids positively correlates with paleoclimate change. During dry or warm intervals, highly aromatized products such as tetraaromatic triterpenes become predominant over their triaromatic homologs. In contrast, triaromatic triterpenes become dominant during wet or cold intervals. In addition, this study provides further evidence to support that the climate pattern in the middle reaches of the Yangtze River is different from that in north China during 13-9.4 ka. These findings suggest that aromatic triterpenes can be valuable tools for Holocene paleoenvironmental reconstructions.

  18. Alteration in delayed fluorescence characterize the effect of heat stress on plants

    Science.gov (United States)

    Zeng, Lizhang; Xing, Da

    2005-02-01

    High temperature affects the photosynthetic functions of plants by its effects on the rate of chemical reactions and on structural organization. Delayed fluorescence originated from the reaction center of photosystem II (PSII) during the photosynthesis process shortly after stopped illumination. With lamina of soybean as a testing model, the effects of high temperature stress on plant photosynthesis capability were studied with various spectral analysis methods. Experimental results show that DF spectrum and Excitation spectrum can probably characterize the changes of soybean photosynthesis capability after different high temperature treatments. Meanwhile, the injury and harm degree of heat stress on soybean leaves were further studied by the variability of its chloroplast absorption spectrum. DF spectroscopy method may provide a new approach for fast detection of the effects of environment stresses on plant photosynthesis capability.

  19. 2010 Annual Wastewater Reuse Report for the Idaho National Laboratory Site's Central Facilities Area Sewage Treatment Plant

    Energy Technology Data Exchange (ETDEWEB)

    Mike lewis

    2011-02-01

    This report describes conditions, as required by the state of Idaho Wastewater Reuse Permit (#LA-000141-03), for the wastewater land application site at Idaho National Laboratory Site’s Central Facilities Area Sewage Treatment Plant from November 1, 2009, through October 31, 2010. The report contains the following information: • Site description • Facility and system description • Permit required monitoring data and loading rates • Status of special compliance conditions • Discussion of the facility’s environmental impacts. During the 2010 permit year, approximately 2.2 million gallons of treated wastewater was land-applied to the irrigation area at Central Facilities Area Sewage Treatment plant.

  20. 2012 Annual Wastewater Reuse Report for the Idaho National Laboratory Site's Central facilities Area Sewage Treatment Plant

    Energy Technology Data Exchange (ETDEWEB)

    Mike Lewis

    2013-02-01

    This report describes conditions, as required by the state of Idaho Wastewater Reuse Permit (#LA-000141-03), for the wastewater land application site at Idaho National Laboratory Site’s Central Facilities Area Sewage Treatment Plant from November 1, 2011, through October 31, 2012. The report contains the following information: • Site description • Facility and system description • Permit required monitoring data and loading rates • Status of compliance conditions and activities • Discussion of the facility’s environmental impacts. During the 2012 permit year, no wastewater was land-applied to the irrigation area of the Central Facilities Area Sewage Treatment Plant.

  1. Long term energy yield measurements of a string- vs. central inverter concept tested on a large scale PV-plant

    DEFF Research Database (Denmark)

    Paasch, Kasper; Nymand, Morten; Kjær, Søren Bækhøj

    2015-01-01

    High speed long term recording of inverter data has been performed on a utility scale PV plant and two different configurations of panel groups are compared. The recorded impact of partial shading due to moving clouds on a sting based and a central inverter based concept is analyzed.......High speed long term recording of inverter data has been performed on a utility scale PV plant and two different configurations of panel groups are compared. The recorded impact of partial shading due to moving clouds on a sting based and a central inverter based concept is analyzed....

  2. Naturalization of central European plants in North America: species traits, habitats, propagule pressure, residence time.

    Science.gov (United States)

    Pyšek, Petr; Manceur, Ameur M; Alba, Christina; McGregor, Kirsty F; Pergl, Jan; Stajerová, Katerina; Chytrý, Milan; Danihelka, Jiří; Kartesz, John; Klimesova, Jitka; Lucanova, Magdalena; Moravcová, Lenka; Nishino, Misako; Sadlo, Jiri; Suda, Jan; Tichy, Lubomir; Kühn, Ingolf

    2015-03-01

    The factors that promote invasive behavior in introduced plant species occur across many scales of biological and ecological organization. Factors that act at relatively small scales, for example, the evolution of biological traits associated with invasiveness, scale up to shape species distributions among different climates and habitats, as well as other characteristics linked to invasion, such as attractiveness for cultivation (and by extension propagule pressure). To identify drivers of invasion it is therefore necessary to disentangle the contribution of multiple factors that are interdependent. To this end, we formulated a conceptual model describing the process of invasion of central European species into North America based on a sequence of "drivers." We then used confirmatory path analysis to test whether the conceptual model is supported by a statistical model inferred from a comprehensive database containing 466 species. The path analysis revealed that naturalization of central European plants in North America, in terms of the number of North American regions invaded, most strongly depends on residence time in the invaded range and the number of habitats occupied by species in their native range. In addition to the confirmatory path analysis, we identified the effects of various biological traits on several important drivers of the conceptualized invasion process. The data supported a model that included indirect effects of biological traits on invasion via their effect on the number of native range habitats occupied and cultivation in the native range. For example, persistent seed banks and longer flowering periods are positively correlated with number of native habitats, while a stress-tolerant life strategy is negatively correlated with native range cultivation. However, the importance of the biological traits is nearly an order of magnitude less than that of the larger scale drivers and highly dependent on the invasion stage (traits were associated

  3. Assessment of fluid-elastic vibration of tube bundle of nuclear power plant heat exchanger

    International Nuclear Information System (INIS)

    Fluid-elastic vibrations of tubes are a frequent cause of failures of heat exchanger tube systems with transverse flow of liquid. The configuration is described of tubes in a heat exchanger designed for a nuclear power plant, and the stability threshold, critical frequency and critical velocity of liquid flow are defined. Formulae are listed used by different authors for critical velocity. Formulae suitable for the described type of heat exchanger were selected and the value of the constant in the formulae determined on a model. The calculated critical velocities and critical frequencies for the inserted and the main bundle of hairpins of the heat exchanger under study are tabulated. The logarithmic decrement of hairpin attenuation required for the calculation of critical velocity was determined on a steel tube model. The calculated values showed that a certain danger of fluid-elastic vibrations is present for both heat exchanger bundles. However, the conclusions are only approximative and should be tested on a large, more accurate model. (A.K.)

  4. Correct safety requirements during the life cycle of heating plants; Korrekta saekerhetskrav under vaermeanlaeggningars livscykel

    Energy Technology Data Exchange (ETDEWEB)

    Tegehall, Jan; Hedberg, Johan [Swedish National Testing and Research Inst., Boraas (Sweden)

    2006-10-15

    The safety of old steam boilers or hot water generators is in principle based on electromechanical components which are generally easy to understand. The use of safety-PLC is a new and flexible way to design a safe system. A programmable system offers more degrees of freedom and consequently new problems may arise. As a result, new standards which use the Safety Integrity Level (SIL) concept for the level of safety have been elaborated. The goal is to define a way of working to handle requirements on safety in control systems of heat and power plants. SIL-requirements are relatively new within the domain and there is a need for guidance to be able to follow the requirements. The target of this report is the people who work with safety questions during new construction, reconstruction, or modification of furnace plants. In the work, the Pressure Equipment Directive, 97/23/EC, as well as standards which use the SIL concept have been studied. Additionally, standards for water-tube boilers have been studied. The focus has been on the safety systems (safety functions) which are used in water-tube boilers for heat and power plants; other systems, which are parts of these boilers, have not been considered. Guidance has been given for the aforementioned standards as well as safety requirements specification and risk analysis. An old hot water generator and a relatively new steam boiler have been used as case studies. The design principles and safety functions of the furnaces have been described. During the risk analysis important hazards were identified. A method for performing a risk analysis has been described and the appropriate content of a safety requirements specification has been defined. If a heat or power plant is constructed, modified, or reconstructed, a safety life cycle shall be followed. The purpose of the safety life cycle is to plan, describe, document, perform, check, test, and validate that everything is correctly done. The components of the safety

  5. Steady-state chlorophyll fluorescence (Fs) as a tool to monitor plant heat and drought stress

    Science.gov (United States)

    Cendrero Mateo, M.; Carmo-Silva, A.; Salvucci, M.; Moran, S. M.; Hernandez, M.

    2012-12-01

    Crop yield decreases when photosynthesis is limited by heat or drought conditions. Yet farmers do not monitor crop photosynthesis because it is difficult to measure at the field scale in real time. Steady-state chlorophyll fluorescence (Fs) can be used at the field level as an indirect measure of photosynthetic activity in both healthy and physiologically-perturbed vegetation. In addition, Fs can be measured by satellite-based sensors on a regular basis over large agricultural regions. In this study, plants of Camelina sativa grown under controlled conditions were subjected to heat and drought stress. Gas exchange and Fs were measured simultaneously with a portable photosynthesis system under light limiting and saturating conditions. Results showed that Fs was directly correlated with net CO2 assimilation (A) and inversely correlated with non-photochemical quenching (NPQ). Analysis of the relationship between Fs and Photosynthetically Active Radiation (PAR) revealed significant differences between control and stressed plants that could be used to track the status, resilience, and recovery of photochemical processes. In summary, the results provide evidence that Fs measurements, even without normalization, are an easy means to monitor changes in plant photosynthesis, and therefore, provide a rapid assessment of plant stress to guide farmers in resource applications. Figure1. Net CO2 assimilation rate (A) of Camelina sativa plants under control conditions and after heat stress exposure for 1 or 3 days (1d-HS and 3d-HS, respectively) (right) and control, drought and re-watering conditions (left). Conditions for infra-red gas analysis were: reference CO2 = 380 μmol mol-1, PPFD = 500 μmol m-2 s-1 and Tleaf set to 25°C (control, drought and re-water) or 35°C (HS). Different letters denote significant differences at the α=0.05 level. Values are means±SEM (n=10). Figure 2. Stable chlorophyll fluorescence (Fs) of Camelina sativa plants under control conditions and

  6. Analysis of thermohydraulic limits during WWER-1000 nuclear power plants heat-up using RELAP5 system code

    International Nuclear Information System (INIS)

    Plant heat-up is a process which all operating systems such as primary coolant circuit, pressurizer, primary and secondary sides of the steam generators and etc. are transferred from a cold shutdown to a hot standby status. During plant heat-up, some thermohydraulic limitations such as maximum and minimum allowable pressure and maximum rate of increase in pressure and temperature which are recommended by plant commissioning program and NPP safety related documents should be considered. Maximum allowable pressure prevents brittle fracture in reactor vessel, Minimum allowable pressure in the inlet of the reactor coolant pumps (RCPs) prevent pump cavitations and maximum allowable rate of increase in temperature and pressure respectively prevent thermal and mechanical shocks. Thus, tuning pressure and temperature increasing rates during plant heat-up is important from plant safety point of view. The RELAP5 system code was used to model and analysis the behavior of WWER-1000 plants during heat-up. In plant heat-up, at first the primary circuit pressure increases by injection of N2 gas into pressurizer in order to provide minimum required NPSH (net positive suction head) for operation of the RCPs. After short time RCPs are turned on to operate which increases the primary coolant circuit temperature through friction losses. At a time which is specified by heat-up procedure the pressurizer heaters are turning on to increase the primary circuit pressure. Heat transfer from primary to secondary side in the steam generators causes increasing of the secondary side temperature and pressure. Temperature and pressure of primary and secondary circuits increase until plant reaches to hot standby condition. The results show that the thermohydraulic parameters during plant heat-up are in an acceptable range and have a good agreement with available data in technical documents. (authors)

  7. Central unresolved issues in thermal energy storage for building heating and cooling

    Energy Technology Data Exchange (ETDEWEB)

    Swet, C.J.; Baylin, F.

    1980-07-01

    This document explores the frontier of the rapidly expanding field of thermal energy storage, investigates unresolved issues, outlines research aimed at finding solutions, and suggests avenues meriting future research. Issues related to applications include value-based ranking of storage concepts, temperature constraints, consistency of assumptions, nomenclature and taxonomy, and screening criteria for materials. Issues related to technologies include assessing seasonal storage concepts, diurnal coolness storage, selection of hot-side storage concepts for cooling-only systems, phase-change storage in building materials, freeze protection for solar water heating systems, and justification of phase-change storage for active solar space heating.

  8. Exergoeconomic performance optimization of an endoreversible intercooled regenerative Brayton combined heat and power plant coupled to variable-temperature heat reservoirs

    Directory of Open Access Journals (Sweden)

    Bo Yang, Lingen Chen, Fengrui Sun

    2012-01-01

    Full Text Available An endoreversible intercooled regenerative Brayton combined heat and power (CHP plant model coupled to variable-temperature heat reservoirs is established. The exergoeconomic performance of the CHP plant is investigated using finite time thermodynamics. The analytical formulae about dimensionless profit rate and exergy efficiency of the CHP plant with the heat resistance losses in the hot-, cold- and consumer-side heat exchangers, the intercooler and the regenerator are deduced. By taking the maximum profit rate as the objective, the heat conductance allocation among the five heat exchangers and the choice of intercooling pressure ratio are optimized by numerical examples, the characteristic of the optimal dimensionless profit rate versus corresponding exergy efficiency is investigated. When the optimization is performed further with respect to the total pressure ratio, a double-maximum profit rate is obtained. The effects of the design parameters on the double-maximum dimensionless profit rate and corresponding exergy efficiency, optimal total pressure ratio and optimal intercooling pressure ratio are analyzed in detail, and it is found that there exist an optimal consumer-side temperature and an optimal thermal capacitance rate matching between the working fluid and the heat reservoir, respectively, corresponding to a thrice-maximum dimensionless profit rate.

  9. Exergoeconomic performance optimization of an endoreversible intercooled regenerative Brayton combined heat and power plant coupled to variable-temperature heat reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Bo; Chen, Lingen; Sun, Fengrui [College of Naval Architecture and Power, Naval University of Engineering, Wuhan 430033 (China)

    2012-07-01

    An endoreversible intercooled regenerative Brayton combined heat and power (CHP) plant model coupled to variable-temperature heat reservoirs is established. The exergoeconomic performance of the CHP plant is investigated using finite time thermodynamics. The analytical formulae about dimensionless profit rate and exergy efficiency of the CHP plant with the heat resistance losses in the hot-, cold- and consumer-side heat exchangers, the intercooler and the regenerator are deduced. By taking the maximum profit rate as the objective, the heat conductance allocation among the five heat exchangers and the choice of intercooling pressure ratio are optimized by numerical examples, the characteristic of the optimal dimensionless profit rate versus corresponding exergy efficiency is investigated. When the optimization is performed further with respect to the total pressure ratio, a double-maximum profit rate is obtained. The effects of the design parameters on the double-maximum dimensionless profit rate and corresponding exergy efficiency, optimal total pressure ratio and optimal intercooling pressure ratio are analyzed in detail, and it is found that there exist an optimal consumer-side temperature and an optimal thermal capacitance rate matching between the working fluid and the heat reservoir, respectively, corresponding to a thrice-maximum dimensionless profit rate.

  10. In vitro antimicrobial activity of plants used in traditional medicine in Gurage and Silti Zones, south central Ethiopia

    OpenAIRE

    Teka Sahile, Alemtshay; Rondevaldova, Johana; Asfaw, Zemede; Demissew, Sebsebe; Van Damme, Patrick; Kokoska, Ladislav; Vanhove, Wouter

    2015-01-01

    Background: To overcome the escalating problems associated with infectious diseases and drug resistance, discovery of new antimicrobials is crucial. The present study aimed to carry out in vitro antimicrobial analysis of 15 medicinal plant species selected according to their traditional medicinal uses in Gurage and Silti Zones, south central Ethiopia. Methods: Ethanol extracts of various plant parts were investigated for their antimicrobial activity against 20 bacterial and one yeast stra...

  11. Robustness analysis of an air heating plant and control law by using polynomial chaos

    International Nuclear Information System (INIS)

    This paper presents a robustness analysis of an air heating plant with a multivariable closed-loop control law by using the polynomial chaos methodology (MPC). The plant consists of a PVC tube with a fan in the air input (that forces the air through the tube) and a mass flux sensor in the output. A heating resistance warms the air as it flows inside the tube, and a thermo-couple sensor measures the air temperature. The plant has thus two inputs (the fan's rotation intensity and heat generated by the resistance, both measured in percent of the maximum value) and two outputs (air temperature and air mass flux, also in percent of the maximal value). The mathematical model is obtained by System Identification techniques. The mass flux sensor, which is nonlinear, is linearized and the delays in the transfer functions are properly approximated by non-minimum phase transfer functions. The resulting model is transformed to a state-space model, which is used for control design purposes. The multivariable robust control design techniques used is the LQG/LTR, and the controllers are validated in simulation software and in the real plant. Finally, the MPC is applied by considering some of the system's parameters as random variables (one at a time, and the system's stochastic differential equations are solved by expanding the solution (a stochastic process) in an orthogonal basis of polynomial functions of the basic random variables. This method transforms the stochastic equations in a set of deterministic differential equations, which can be solved by traditional numerical methods (That is the MPC). Statistical data for the system (like expected values and variances) are then calculated. The effects of randomness in the parameters are evaluated in the open-loop and closed-loop pole's positions

  12. Technology data for energy plants. Individual heating plants and energy transport

    Energy Technology Data Exchange (ETDEWEB)

    2012-05-15

    The present technology catalogue is published in co-operation between the Danish Energy Agency and Energinet.dk and includes technology descriptions for a number of technologies for individual heat production and energy transport. The primary objective of the technology catalogue is to establish a uniform, commonly accepted and up-to-date basis for the work with energy planning and the development of the energy sector, including future outlooks, scenario analyses and technical/economic analyses. The technology catalogue is thus a valuable tool in connection with energy planning and assessment of climate projects and for evaluating the development opportunities for the energy sector's many technologies, which can be used for the preparation of different support programmes for energy research and development. The publication of the technology catalogue should also be viewed in the light of renewed focus on strategic energy planning in municipalities etc. In that respect, the technology catalogue is considered to be an important tool for the municipalities in their planning efforts. (LN)

  13. Examples of power generation and heat utilization in solid waste processing plants. Minami solid waste processing plant, Matsue District Environmental Sanitation Association

    Energy Technology Data Exchange (ETDEWEB)

    Ishihara, J.

    1981-01-01

    The plant has a solid waste processing capacity of 150t/16h and incorporates an indoor swimming pool of 25 x 10 x 1m. The outline of the facilities, the layout of the plant and the heat balance are described. The purpose and the mode of use of the indoor swimming pool are described.

  14. Fluid selection and parametric analysis on condensation temperature and plant height for a thermogravimetric heat pump

    International Nuclear Information System (INIS)

    The Thermogravimetric Heat Pump (TGHP) is a non-conventional system, implementing a reverse cycle, the main difference of which from the usual vapor compression (Rankine) cycle is a quasi-isothermal compression of the working fluid by a high heat capacity carrier fluid. Previous studies showed that employing HFC134a or PF5050 as working fluids may be promising in terms of thermodynamic performance, though the corresponding required plant heights confine its application to tall buildings (from minimum height of 10–12 storeys to skyscrapers). Accordingly, an investigation has been carried out in the present study in order to determine a group of fluids which allow lower heights under the same input conditions. In order to investigate the performance of the system and the required plant height, operation of a 100 kW TGHP has been simulated for 17 different fluids. Accordingly, the corresponding COPs and required heights are determined and based on the achieved COPs, the optimum fluid for each range of building height is selected. The resulting plant heights range from 20 m to nearly 200 m and R245ca is shown to be the most promising fluid for the lowest plant height range. A parametric study is next carried out in order to study the effect of variations in the condensation temperature and the dimensionless plant height on the performance of the system. The obtained results demonstrate that an increase in the former from 313 K to 348 K, for almost all of the analyzed fluids, causes a reduction of around 50% in the COP. It is also shown that, almost independent of the employed fluid, the maximum values of COP are reached for a dimensionless plant height of around 1.8. Moreover, all the analyzed fluids show basically the same COP trend and, at the same operating conditions, the COP values for all fluids are within a 10% range of variation. This leads to the conclusion that the thermophysical properties of the employed fluid mainly influences the required height of

  15. Combined heat and power plants with parallel tandem steam turbines; Smaaskalig kraftvaerme med parallellkopplade tandemturbiner

    Energy Technology Data Exchange (ETDEWEB)

    Steinwall, Pontus; Norstroem, Urban; Pettersson, Camilla; Oesterlin, Erik

    2004-12-01

    We investigate the technical and economical conditions for a concept with parallel coupled tandem turbines in small scale combined heat and power plants fired with bio-fuel and waste. Performance and heat production costs at varying electricity prices for the concept with two smaller tandem coupled steam turbines has been compared to the traditional concept with one single multi-staged turbine. Three different types of plants have been investigated: - Bio fuelled CHP plant with thermal capacity of 15 MW{sub th}; - Waste fired CHP plant with thermal capacity of 20 MW{sub th}; - Bio fuelled CHP plant with thermal capacity of 25 MW{sub th}. The simple steam turbines (Curtis turbines) used in the tandem arrangement has an isentropic efficiency of about 49 to 53% compared to the multi-staged steam turbines with isentropic efficiency in the range of 59% to 81%. The lower isentropic efficiency for the single staged turbines is to some extent compensated at partial load when one of the two turbines can be shut down leading to better operational conditions for the one still in operation. For concepts with saturated steam at partial load below 50% the tandem arrangements presents higher electricity efficiency than the conventional single turbine alternative. The difference in annual production of electricity is therefore less than the difference in isentropic efficiency for the two concepts. Production of electricity is between 2% and 42% lower for the tandem arrangements in this study. Investment costs for the turbine island has been calculated for the two turbine concepts and when the costs for turbines, generator, power transmission, condensing system, piping system, buildings, assembling, commissioning and engineering has been added the sum is about the same for the two concepts. For the bio-fuelled plant with thermal capacity of 15 MW{sub th} the turbine island amount to about 10-12 MSEK and about 13-15 MSEK for the waste fired plant with a thermal capacity of 20 MW

  16. A Novel approach for Low temperature Condenser waste heat Utilization in winter air conditioning for overall Performance Improvement of a Power Plant in Northern India

    Directory of Open Access Journals (Sweden)

    Rajendra Kumar Yadav

    2014-10-01

    Full Text Available The objective of this paper to highlight the scope of utilization of waste heat of condenser for winter air conditioning in and around thermal power stations. The vast amount of low grade condenser waste heat can be used to provide winter air conditioning by utilizing the existing system of year round central air conditioning without additional heavy capital expenditure .The present case study is about North India where peak winter lasts about 90 days . The waste heat utilization for winter conditioning will not only save large amount of electrical energy being used in electrical heaters but also generate additional revenue by selling out extra/spared power ,increase thermal energy utilization ,improve performance of the plant .The novel method of winter air conditioning will also reduce the heat load of the cooling towers, avoid pumping and blow down power as the returning water from air conditioning system can be used as blow down to maintain cooling water parameters in the plant.

  17. The market potential for solar heating plants in some European countries

    International Nuclear Information System (INIS)

    This study evaluates the market potential for solar collectors for residential heating in six European countries: Sweden, Denmark, Germany, Netherlands, Italy and Greece. The study is based on statistical information about the population, buildings, energy consumption and climatic conditions in the respective regions. The market potential was determined for systems supplying hot water and space heating in small houses and multi family houses, as well as for central block heating and district heating systems. Only systems with diurnal storage were taken into account. The technical potential was derived by analyzing the available roof areas, making allowance construction obstacles, unfavourable orientation, shadowing etc. Furthermore, commercial considerations, such as cost of competing energy sources, e.g. cogeneration and other low cost sources were considered. In accordance with our expectations, we assumed that the solar costs will decrease by 30 to 50% and that the market will increase by 30%/year during the next ten years, due to growing energy prices and by public financial support in an initial phase. It was found that there exists a commercial solar energy market in Greece for small systems and that the market could be nearly commercial in Italy. In the other countries the market must be stimulated by subsidies in order to take off. The total net potential for solar collectors in the six countries was found to about 100 Mm2 for small systems, and 60 Mm2 for large systems, corresponding to about 70 TWh/year. In a rough estimate we can say that the net solar collector market potential is about 1 m2/inhabitant in north and central Europe, and 0.5m2 in south Europe. Although systems for seasonal storage were not included in our analysis, it is probable that these systems will increase the net market potential by a factor of 2-3. 9 refs

  18. Studying effect of heating plant parameters on performances of a geothermal-fuelled series cogeneration plant based on Organic Rankine Cycle

    International Nuclear Information System (INIS)

    Highlights: • We analyzed performances of a series ORC–CHP plant versus the heating plant parameters. • ORC–CHP power is destructed when raising the heat demand or the return temperature. • Only the high supply temperatures of the heating plant affect negatively the performances. • Reducing the return temperature optimizes both the energetic and exergetic criteria. • Increasing the heat demand improves the exergetic efficiency of the total CHP system. - Abstract: The present work aims to analyze the performance characteristics of the series Combined Heat and Power (CHP) system based on Organic Rankine Cycle (ORC) under influence of the heating plant parameters without considering the chemistry of the geothermal water considered as heat source. For evaluation, energetic and exergetic criteria along with the heat transfer capacities have been determined, and also the working fluid R134a has been used. The results showed that increasing the heat demand or the return temperature and only the high supply temperatures lead to destruct the net power generated by the ORC–CHP system. While, influence of the last parameters on the total exergy efficiency and losses is different; whereas raising the heat demands optimizes these exergetic indicators, variation of the supply temperature leads to an optimum for these performances. Since increasing the return temperature has purely negative impacts on all exergetic and energetic criteria, the latter can be improved by reducing this temperature with attention to the heat transfer capacities. Thus, reduction of the return temperature about 5 °C lowers the exhausted stream losses by app. 25% and enhances the power generation by app. 52% and the total exergy efficiency by 9%

  19. 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

    Energy Technology Data Exchange (ETDEWEB)

    Mani, Sudhagar [University of Georgia; Sokhansanj, Shahabaddine [ORNL; Togore, Sam [U.S. Department of Energy; Turhollow Jr, Anthony F [ORNL

    2010-03-01

    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 dam3). 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.

  20. 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

    Energy Technology Data Exchange (ETDEWEB)

    Mani, S. [Biological and Agricultural Engineering, Driftmier Engineering Center, University of Georgia, Athens, GA 30602 (United States); Sokhansanj, S.; Turhollow, A.F. [Environmental Sciences Division, Oak Ridge National Laboratory, P. O. Box 2008, Oak Ridge, TN 37831 (United States); Tagore, S. [Office of Biomass Program, U.S. Department of Energy, Washington, DC 20585 (United States)

    2010-03-15

    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{sup 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. (author)

  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)

    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 dam3). 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. Design of dedicated nuclear desalination system Low pressure Inherent heat sink Nuclear Desalination plant: LIND

    International Nuclear Information System (INIS)

    This study is for developing a dedicated nuclear desalination system equipped with highly passive safety features. The target site of the project is Abu Dhabi Emirate in UAE. Low pressure Inherent heat sink Nuclear Desalination plant (LIND) adopts the several innovative design concepts: 1) Use of low pressure operation (1-3bar) due to a dedicated nuclear desalination plant; 2) Use of a pool type reactor to have a large water reservoir; 3) Use of square ring type fuel loading to maintain the cladding maximum temperature below the criterion even in accident scenario; 4) Use of SiC as control rod wall, baffle, guide tube, cladding etc. to allow high temperature of that components for decay heat removal; 5) Use of SiC as cladding to permit CHF during worst transients and eliminate H2 explosion; 6) Underground design of a reactor to eliminate concrete wall surrounding a steel containment; 7) Use of reactor cavity for ex vessel cooling; 8) Use of steel containment to effectively remove decay heat through radiation and air convection; 9) Use of In Containment Refueling Water Storage Tank (IRWST) and Desalted Water Storage Tank (DWST) as water storage for safety injection purpose

  3. Pulse*Star Inertial Confinement Fusion Reactor: heat transfer loop and balance of plant considerations

    International Nuclear Information System (INIS)

    A conceptual heat transfer loop and balance of plant design for the Pulse*Star Inertial Confinement Fusion Reactor has been investigated and results are presented. The Pulse*Star reaction vessel, a perforated steel bell jar approximately 11 m in diameter, is immersed in Li17Pb83 coolant which flows through the perforations and forms a 1.5 m thick plenum of droplets around an 8 m diameter inner chamber. The reactor and associated pumps, piping, and steam generators are contained within a 17 m diameter pool of Li17Pb83 coolant to minimize structural requirements and occupied space, resulting in reduced cost. Four parallel heat transfer loops with flow rates of 5.5 m3/s each are necessary to transfer 3300 MWt of power. The steam generator design was optimized by finding the most cost-effective combination of heat exchanger area and pumping power. Power balance calculations based on an improved electrical conversion efficiency revealed a net electrical output of 1260 MWe to the bus bar and a resulting net efficiency of 39%. Suggested balance-of-plant layouts are also presented

  4. Feasibility Assessment of Using Power Plant Waste Heat in Large Scale Horticulture Facility Energy Supply Systems

    Directory of Open Access Journals (Sweden)

    Min Gyung Yu

    2016-02-01

    Full Text Available Recently, the Korean government has been carrying out projects to construct several large scale horticulture facilities. However, it is difficult for an energy supply to operate stably and economically with only a conventional fossil fuel boiler system. For this reason, several unused energy sources have become attractive and it was found that power plant waste heat has the greatest potential for application in this scenario. In this study, we performed a feasibility assessment of power plant waste heat as an energy source for horticulture facilities. As a result, it was confirmed that there was a sufficient amount of energy potential for the use of waste heat to supply energy to the assumed area. In Dangjin, an horticultural area of 500 ha could be constructed by utilizing 20% of the energy reserves. In Hadong, a horticulture facility can be set up to be 260 ha with 7.4% of the energy reserves. In Youngdong, an assumed area of 65 ha could be built utilizing about 19% of the energy reserves. Furthermore, the payback period was calculated in order to evaluate the economic feasibility compared with a conventional system. The initial investment costs can be recovered by the approximately 83% reduction in the annual operating costs.

  5. Mutualistic fungal endophytes produce phytohormones and organic acids that promote japonica rice plant growth under prolonged heat stress*

    OpenAIRE

    Waqas, Muhammad; Khan, Abdul Latif; Shahzad, Raheem; Ullah, Ihsan; Khan, Abdur Rahim; Lee, In-Jung

    2015-01-01

    This study identifies the potential role in heat-stress mitigation of phytohormones and other secondary metabolites produced by the endophytic fungus Paecilomyces formosus LWL1 in japonica rice cultivar Dongjin. The japonica rice was grown in controlled chamber conditions with and without P. formosus LWL1 under no stress (NS) and prolonged heat stress (HS) conditions. Endophytic association under NS and HS conditions significantly improved plant growth attributes, such as plant height, fresh ...

  6. Minnesota Project: district heating and cooling through power plant retrofit and distribution network. Final report. Phase 1. [Minnesota Project

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-01-01

    Appendices are presented for the Minnesota Project: District Heating and Cooling Through Power Plant Retrofit and Distribution Network. These are: SYNTHA results (SYNTHA II is a proprietary program of the SYNTHA Corporation); Market Survey Questionnaire: Environmental Review Procedures; Public Service Commission Regulation of District Heating; Energy Use Normalization Procedures; Power Plant Description; Letters of Commitment; Bond Opinion and Issuance; and Marvin Koeplin Letter, Chairman of Public Service Commission, Moorehead, Minnesota.

  7. Enhancement of LNG plant propane cycle through waste heat powered absorption cooling

    International Nuclear Information System (INIS)

    In liquefied natural gas (LNG) plants utilizing sea water for process cooling, both the efficiency and production capacity of the propane cycle decrease with increasing sea water temperature. To address this issue, several propane cycle enhancement approaches are investigated in this study, which require minimal modification of the existing plant configuration. These approaches rely on the use of gas turbine waste heat powered water/lithium bromide absorption cooling to either (i) subcool propane after the propane cycle condenser, or (ii) reduce propane cycle condensing pressure through pre-cooling of condenser cooling water. In the second approach, two alternative methods of pre-cooling condenser cooling water are considered, which consist of an open sea water loop, and a closed fresh water loop. In addition for all cases, three candidate absorption chiller configurations are evaluated, namely single-effect, double-effect, and cascaded double- and single-effect chillers. The thermodynamic performance of each propane cycle enhancement scheme, integrated in an actual LNG plant in the Persian Gulf, is evaluated using actual plant operating data. Subcooling propane after the propane cycle condenser is found to improve propane cycle total coefficient of performance (COPT) and cooling capacity by 13% and 23%, respectively. The necessary cooling load could be provided by either a single-effect, double-effect or cascaded and single- and double-effect absorption refrigeration cycle recovering waste heat from a single gas turbine operated at full load. Reducing propane condensing pressure using a closed fresh water condenser cooling loop is found result in propane cycle COPT and cooling capacity enhancements of 63% and 22%, respectively, but would require substantially higher capital investment than for propane subcooling, due to higher cooling load and thus higher waste heat requirements. Considering the present trend of short process enhancement payback periods in the

  8. Use of reactor plants of enhanced safety for sea water desalination, industrial and district heating

    International Nuclear Information System (INIS)

    Russian designers have developed and can deliver nuclear complexes to provide sea water desalination, industrial and district heating. This paper provides an overview of these designs utilizing the ABV, KLT-40 and ATETS-80 reactor plants of enhanced safety. The most advanced nuclear powered water desalination project is the APVS-80. This design consists of a special ship equipped with the distillation desalination plant powered at a level of 160 MW(th) utilizing the type KLT-40 reactor plant. More than 20 years of experience with water desalination and reactor plants has been achieved in Aktau and Russian nuclear ships without radioactive contamination of desalinated water. Design is also proceeding on a two structure complex consisting of a floating nuclear power station and a reverse osmosis desalination plant. This new technology for sea water desalination provides the opportunity to considerably reduce the specific consumption of power for the desalination of sea water. The ABV reactor is utilized in the ''Volnolom'' type floating nuclear power stations. This design also features a desalinator ship which provides sea water desalination by the reverse osmosis process. The ATETS-80 is a nuclear two-reactor cogeneration complex which incorporates the integral vessel-type PWR which can be used in the production of electricity, steam, hot and desalinated water. (author). 9 figs

  9. Impact of southern and central European land surface heating induced by greenhouse warming on the atmospheric circulation

    International Nuclear Information System (INIS)

    Full text: A robust result of greenhouse warming runs with global climate models is the depletion of soil moisture in southern and central Europe in summer. This leads to a strong increase in surface temperatures as a result of the accompanying reduction of the surface cooling by evaporation. In a series of sensitivity experiments with the EC-EARTH climate model we investigate the effect of this enhanced warming on the atmospheric circulation. EC-EARTH is a coupled climate model jointly developed by the EC-EARTH consortium and is based on the integrated forecast model of the ECMWF. The sensitivity experiments are designed to test the hypothesis that the enhanced summer surface easterlies over central Europe that are found in many recent climate scenario simulations are mainly due to the development of a heat low over the Mediterranean region in response to the enhanced warming of North Africa and Southern Europe. In the experiments with EC-EARTH the land surface temperature is artificially enhanced by increasing the downward surface solar radiation. This is done in order to enable the soil moisture to respond in a dynamically consistent way to the increase in surface land temperature. A similar approach has been successfully used in a previous study to show that an enhanced Sahara heating results in a deepening of the Sahara low with consequences for the Sahel rainfall. (author)

  10. Seepage at western Sagami Bay, Central Japan: Results from heat flow and seismic reflection

    Science.gov (United States)

    Kinoshita, M.; Machiyama, H.; Yamashita, M.; Soh, W.

    2005-12-01

    The Izu Peninsula on the Philippine Sea Plate (PHS) collides NNW-ward with the mainland Honshu. The subduction boundary at the northern boundary of PHS is thus distorted northward, forming an oblique subduction boundary Sagami Trough to the east of Izu Peninsula. Also a fault plane is inferred at the western Sagami Bay off Hatsushima Island, in order to explain tremors activity. The volcanic front of IBM arc runs at the western Sagami Bay, producing a group of monogenetic volcanoes. Active cold seep communities develop off Hatsushima at 1200 m water depth. Intensive heat flow studies, including dive results and recent survey in 2004 revealed a high heat flow distribution (> 1,000 mWm-2) within 500m of the colony and low (~50 mWm-2) on the Sagami Trough to the east. Hydrological conduit along the potential fault or along the lithologic boundary will feed nutrients to the colony, as well as it will provide heat conductively in the surrounding region. Dive studies revealed almost zero heat flow within 50 m of the colony, whereas heat flow is as high as 20,000 mWm-2 on the colony. Continuous monitoring of heat flow in and outside the colony (only 1m apart) was conducted for 4 years using JAMSTEC_fs cabled observatory. A temperature decrease by 0.8°C only at sensors 10-20 cm below seafloor within the colony occurred within two months. Piston core samples taken in 2003 include massive carbonate crust of 20 cm thickness, which probably forms a hydrological seal. This suggests that the hydrological system here is dynamically supported through time-variant chemical reaction and fluid transport. In 2005 we conducted a grid survey of single-channel seismics at 0.1-0.2 miles interval around the Hatsushima seep community. A potential reservoir, showing negative reflectivity, was located 200-300m below sea floor. We plan to submit a drilling proposal to IODP in this area, in order to characterize hydrological system trough sampling and long-term monitoring.

  11. ClpB/Hsp100 proteins and heat stress tolerance in plants.

    Science.gov (United States)

    Mishra, Ratnesh Chandra; Grover, Anil

    2016-10-01

    High-temperature stress can disrupt cellular proteostasis, resulting in the accumulation of insoluble protein aggregates. For survival under stressful conditions, it is important for cells to maintain a pool of native soluble proteins by preventing and/or dissociating these aggregates. Chaperones such as GroEL/GroES (Hsp60/Hsp10) and DnaK/DnaJ/GrpE (Hsp70/Hsp40/nucleotide exchange factor) help cells minimize protein aggregation. Protein disaggregation is accomplished by chaperones belonging to the Caseinolytic Protease (Clp) family of proteins. ClpB/Hsp100 proteins are strikingly ubiquitous and are found in bacteria, yeast and multi-cellular plants. The expression of these proteins is regulated by heat stress (HS) and developmental cues. Bacteria and yeast contain one and two forms of ClpB proteins, respectively. Plants possess multiple forms of these proteins that are localized to different cellular compartments (i.e. cytoplasm/nucleus, chloroplast or mitochondria). Overwhelming evidence suggests that ClpB/Hsp100 proteins play decisive roles in cell adaptation to HS. Mutant bacteria and yeast cells lacking active ClpB/Hsp100 proteins are critically sensitive to high-temperature stress. Likewise, Arabidopsis, maize and rice mutants lacking cytoplasmic ClpB proteins are very sensitive to heat. In this study, we present the structural and functional attributes of plant ClpB forms. PMID:26121931

  12. Savannah River Plant Low-Level Waste Heat Utilization Project preliminary analysis. Volume II. Options for capturing the waste heat

    International Nuclear Information System (INIS)

    Options for utilizing the heated SRP effluent are investigated. The temperature and availability characteristics of the heated effluent are analyzed. Technical options for energy recovery are discussed. A number of thermodynamic cycles that could generate electrical power using the energy in the heated SRP effluent are described. Conceptual designs for SRP application of two attractive options are presented. Other direct uses for the heated effluent, as heat sources for agriculture and aquaculture options are discussed

  13. To Question оf Using Power Reserve оf Power-and-Heat Supply Turbine Plants

    OpenAIRE

    S. A. Kachan; I. N. Baranovski

    2014-01-01

    The paper considers possibilities and limitations of various methods for obtaining power re-serve at power-and-heat supply turbo-generator sets.Approximate values of specific heat rate and quantity of reserve power and rate of its obtaining for various turbine plants are given in the paper.

  14. Thermal coupling at the Beznau nuclear power plant, Switzerland, of the NOK for the regional district heat supply Refuna

    International Nuclear Information System (INIS)

    A brief review of the pilot district heating supply project, Refuna, is presented. The project involves the coupling of the waste heat from the Beznau nuclear power plant and transporting it in the form of hot water in the Aaretal region of Switzerland. (G.T.H.)

  15. To Question оf Using Power Reserve оf Power-and-Heat Supply Turbine Plants

    Directory of Open Access Journals (Sweden)

    S. A. Kachan

    2014-06-01

    Full Text Available The paper considers possibilities and limitations of various methods for obtaining power re-serve at power-and-heat supply turbo-generator sets.Approximate values of specific heat rate and quantity of reserve power and rate of its obtaining for various turbine plants are given in the paper.

  16. An ethnobotanical study of plants used for the treatment of livestock diseases in Tikamgarh District of Bundelkhand, Central India

    Institute of Scientific and Technical Information of China (English)

    Raj Kumar Verma

    2014-01-01

    Objective: To explore and document the information regarding usage of ethnoveterinary medicinal plants utilized by rural farmers and traditional herbal healers for livestock healthcare in Tikamgarh District of Bundelkhnad, Central India. Methods: The remote villages of Tikamgarh district were regularly visited from July 2011 to June 2012. Following the methods of Jain and Goel (1995) information regarding the usage of ethnoveterinary medicinal plants was collected.Results:various plant parts and their combinations for the treatment of more than 36 diseases in the studied area. Trees (17 species) were found to be the most used Ethnoveterinary medicinal plants followed by herbs (15 species), shrubs (6 species) and grasses (3) in descending order. The most common diseases cough, diarrhoea and fever were treated by 04 ethnoveterinary medicinal plant species.Conclusions:The present study recommended that the crop and medicinal plant genetic A total of 41 plant species in 39 genera and 25 families were used traditionally with resources cannot be conserved and protected without conserving/managing of the agro-ecosystem or natural habitat of medicinal plants and the socio-cultural organization of the local people. The same may be applied to protect indigenous knowledge, related to the use of medicinal and other wild plants. Introduction of medicinal plants in degraded government and common lands could be another option for promoting the rural economy together with environmental conservation, but has not received attention in the land rehabilitation programs in this region.

  17. 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

  18. Comparative analysis of the performance of string and central inverter topology at a large PV utility plant with varying topography

    DEFF Research Database (Denmark)

    Paasch, Kasper; Nymand, Morten; Kjær, Søren Bækhøj

    MPPT) and a series of small central inverters (60 kW, 1 MPPT) in the same PV plant under varying irradiation conditions and also including the potential detrimental effect of the horizontally tilt of the solar panels due to area topography variation. It has been shown that the gain from using multiple...

  19. A New Method to Determine Central Wavelength and Optimal Bandwidth for Predicting Plant Nitrogen Uptake in Winter Wheat

    Institute of Scientific and Technical Information of China (English)

    YAO Xin-feng; YAO Xia; TIAN Yong-chao; NI Jun; LIU Xiao-jun; CAO Wei-xing; ZHU Yan

    2013-01-01

    Plant nitrogen (N) uptake is a good indicator of cropNstatus. In this study, a new method was designed to determine the central wavelength, optimal bandwidth and vegetation indices for predicting plantNuptake (gNm-2) in winter wheat (Triticum aestivum L.). The data were collected from the ground-based hyperspectral reflectance measurements in eight field experiments on winter wheat of different years, eco-sites, varieties,Nrates, sowing dates, and densities. The plantNuptake index (PNUI) based on NDVI of 807 nm combined with 736 nm was selected as the optimal vegetation index, and a linear model was developed with R2 of 0.870 and RMSE of 1.546 gNm-2 for calibration, and R2 of 0.834, RMSE of 1.316 gNm-2, slope of 0.934, and intercept of 0.001 for validation. Then, the effect of the bandwidth of central wavelengths on model performance was determined based on the interaction between central wavelength and bandwidth expansion. The results indicated that the optimal bandwidth varies with the changes of the central wavelength and with the interaction between the two bands in one vegetation index. These findings are important for prediction and diagnosis of plantNuptake more precise and accurate in crop management.

  20. 2015 Annual Wastewater Reuse Report for the Idaho National Laboratory Site’s Central Facilities Area Sewage Treatment Plant

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Michael George [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-02-01

    This report describes conditions, as required by the state of Idaho Wastewater Reuse Permit (#LA-000141-03), for the wastewater land application site at the Idaho National Laboratory Site’s Central Facilities Area Sewage Treatment Plant from November 1, 2014, through October 31, 2015.

  1. A Conceptual Design Study on the Application of Liquid Metal Heat Transfer Technology to the Solar Thermal Power Plant

    Science.gov (United States)

    Zimmerman, W. F.; Robertson, C. S.; Ehde, C. L.; Divakaruni, S. M.; Stacy, L. E.

    1979-01-01

    Alkali metal heat transfer technology was used in the development of conceptual designs for the transport and storage of sensible and latent heat thermal energy in distributed concentrator, solar Stirling power conversion systems at a power level of 15 kWe per unit. Both liquid metal pumped loop and heat pipe thermal transport were considered; system configurations included: (1) an integrated, focal mounted sodium heat pipe solar receiver (HPSR) with latent heat thermal energy storage; (2) a liquid sodium pumped loop with the latent heat storage, Stirling engine-generator, pump and valves located on the back side of the concentrator; and (3) similar pumped loops serving several concentrators with more centralized power conversion and storage. The focus mounted HPSR was most efficient, lightest and lowest in estimated cost. Design confirmation testing indicated satisfactory performance at all angles of inclination of the primary heat pipes to be used in the solar receiver.

  2. On meridional circulation and heat budget of the troposphere over the Equatorial Central Pacific

    OpenAIRE

    Hastenrath, Stefan L.

    2011-01-01

    The existence of an equatorial dry zone in the Central Pacific enclosed between moister belts in both hemispheres is borne out by rainfall measurements and daily ESSA III and ESSA V cloud mosaics. The tropospheric wind regime is studied mainly on the basis of aerological soundings during the Line Islands Experiment (LIE) in spring 1967 and observations of earlier periods. During LIE, upper-tropospheric Westerlies extend continuously across the equator. In the lower layers, Easterlies dominate...

  3. Modelling, Simulation and Identification of Heat Loss Mechanisms for Parabolic Trough Receivers Installed in Concentrated Solar Power Plants

    OpenAIRE

    Caron, Simon; Röger, Marc

    2015-01-01

    This paper describes a thermodynamic model library developed with the object-oriented language Modelica, which is both implemented for steady-state and transient heat transfer analyses of Parabolic Trough Receivers (PTRs) installed in Concentrated Solar Power (CSP) plants. For the identification of PTR heat loss mechanisms, this heat transfer model is coupled to a derivative-free hybrid optimization routine developed in Matlab, combining a Particle Swarm Optimization (PSO) algorithm with a...

  4. RDF to energy plant for a central Italian region SUW management system: Energetic and economical analysis

    International Nuclear Information System (INIS)

    It is well known that a rise in a country's prosperity is parallel to an increase in the amount of waste produced by the population. The specific solid urban waste production off a European citizen is actually about 500 kg per inhabitant per year. In reference to the whole European population, the global solid urban waste production requires an adequate management system, able to satisfy economical, social and environmental needs. Before final disposal (i.e. sanitary landfill), wastes need some kind of recovery, reuse and ad hoc treatments operation, in compliance with European state laws. The aim of these rules is to achieve an environmentally sound waste management system, that allows to reduce raw materials and fossil fuel consumption, dangerous waste production and the amount of disposed materials. Among the technologies available for the different treatments, incineration with energy recovery seems to have many advantages mainly because it reduces waste volume and fossil fuel consumption, and because its sterilization effects are achieved on the inlet substances. The main drawbacks of such plants are represented by the emission off gaseous pollutant, thus requiring important exhaust gasses treatment systems, by producing a non-negligible amount of dangerous substances, and by high capital and operating costs. In this paper the solid urban waste production of a central Italian region and the amount of available residual derived fuel for thermal treatment has been assessed. Then, the possibility of exploiting a fluid bed combustor based power plant, able to treat the residual derive fuel fraction produced through the years, has been analyzed both from an energetic and an economical point of view

  5. Combined heat and power (cogeneration) plant based on renewable energy sources and electrochemical hydrogen systems

    Science.gov (United States)

    Grigor'ev, S. A.; Grigor'ev, A. S.; Kuleshov, N. V.; Fateev, V. N.; Kuleshov, V. N.

    2015-02-01

    The layout of a combined heat and power (cogeneration) plant based on renewable energy sources (RESs) and hydrogen electrochemical systems for the accumulation of energy via the direct and inverse conversion of the electrical energy from RESs into the chemical energy of hydrogen with the storage of the latter is described. Some efficient technical solutions on the use of electrochemical hydrogen systems in power engineering for the storage of energy with a cyclic energy conversion efficiency of more than 40% are proposed. It is shown that the storage of energy in the form of hydrogen is environmentally safe and considerably surpasses traditional accumulator batteries by its capacitance characteristics, being especially topical in the prolonged absence of energy supply from RESs, e.g., under the conditions of polar night and breathless weather. To provide the required heat consumption of an object during the peak period, it is proposed to burn some hydrogen in a boiler house.

  6. Use of geothermal heat for sugar refining in Imperial County: pilot plant implementation

    Energy Technology Data Exchange (ETDEWEB)

    1984-09-01

    The objective of the phase was to develop a successful geothermal resource and use it in conjunction with a geothermal process heat pilot plant to demonstrate the adequacy of a system which could provide technically sound, economical and environmentally acceptable process heat. During the second phase drilling of and exploratory production well was carried out. The well reached a total depth of about 10,000 feet. Static bottom hole temperatures as high as 393 degreees F were calculated. However, the well did not produce a free flow of more than 2 to 3 barrels of brine per hour. Attempts were made to stimulate the well by gas lift and circulation. These procedures were unsuccessful in promoting flow, and the well was shut in. At that point the DOE decided to terminate the project.

  7. Gallium-cladding compatibility testing plan: Phase 3: Test plan for centrally heated surrogate rodlet test. Revision 2

    International Nuclear Information System (INIS)

    The Fissile Materials Disposition Program (FMDP) is investigating the use of weapons grade plutonium in mixed oxide (MOX) fuel for light-water reactors (LWR). Commercial MOX fuel has been successfully used in overseas reactors for many years; however, weapons derived fuel may differ from the previous commercial fuels because of small amounts of gallium impurities. A concern presently exists that the gallium may migrate out of the fuel, react with and weaken the clad, and thereby promote loss of fuel pin integrity. Phases 1 and 2 of the gallium task are presently underway to investigate the types of reactions that occur between gallium and clad materials. This is a Level-2 document as defined in the Fissile Materials Disposition Program Light-Water Reactor Mixed-Oxide Fuel Irradiation Test Project Plan. This Plan summarizes the projected Phase 3 Gallium-Cladding compatibility heating test and the follow-on post test examination (PTE). This work will be performed using centrally-heated surrogate pellets, to avoid unnecessary complexities and costs associated with working with plutonium and an irradiation environment. Two sets of rodlets containing pellets prepared by two different methods will be heated. Both sets will have an initial bulk gallium content of approximately 10 ppm. The major emphasis of the PTE task will be to examine the material interactions, particularly indications of gallium transport from the pellets to the clad

  8. Surface Heat Budget and Solar Radiation Allocation at a Melt Pond During Summer in the Central Arctic Ocean

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shugang; ZHAO Jinping; SHI Jiuxin; JIAO Yutian

    2014-01-01

    The heat budget of a melt pond surface and the solar radiation allocation at the melt pond are studied using the 2010 Chinese National Arctic Research Expedition data collected in the central Arctic. Temperature at a melt pond surface is proportional to the air temperature above it. However, the linear relationship between the two varies, depending on whether the air temperature is higher or lower than 0℃. The melt pond surface temperature is strongly influenced by the air temperature when the latter is lower than 0℃. Both net longwave radiation and turbulent heat flux can cause energy loss in a melt pond, but the loss by the latter is larger than that by the former. The turbulent heat flux is more than twice the net longwave radiation when the air temperature is lower than 0℃. More than 50%of the radiation energy entering the pond surface is absorbed by pond water. Very thin ice sheet on the pond surface (black ice) appears when the air temperature is lower than 0℃; on the other hand, only a small percentage (5.5%) of net longwave in the solar radiation is absorbed by such a thin ice sheet.

  9. Effects of N on Plant Response to Heat-wave: A Field Study with Prairie Vegetation

    Institute of Scientific and Technical Information of China (English)

    Dan Wang; Scott A. Heckathorn; Kumar Mainali; E. William Hamilton

    2008-01-01

    More intense, more frequent, and longer heat-waves are expected in the future due to global warming, which could have dramatic ecological impacts. Increasing nitrogen (N) availability and its dynamics will likely impact plant responses to heat stress and carbon (C) sequestration in terrestrial ecosystems. This field study examined the effects of N availability on plant response to heat-stress (HS) treatment in naturally-occurring vegetation. HS (5 d at ambient or 40.5 ℃) and N treatments (±N) were applied to 16 1 m2 plots in restored prairie vegetation dominated by Andropogon gerardii (warm-season C4 grass) and Solidago canadensis (warm-season C3 forb). Before, during, and after HS, air, canopy, and soil temperature were monitored; net CO2 assimilation (Pn), quantum yield of photosystem Ⅱ (φPsⅡ), stomatal conductance (gs), and leaf water potential (Ψw) of the dominant species and soil respiration (Rsolf) of each plot were measured daily during HS. One week after HS, plots were harvested, and C% and N% were determined for rhizosphere and bulk soil, and above-ground tissue (green/senescent leaf, stem, and flower). Photosynthetic N-use efficiency (PNUE) and N resorption rate (NRR) were calculated. HS decreased Pn, gs, Ψw, and PNUE for both species, and +N treatment generally increased these variables (±HS), but often slowed their poat-HS recovery. Aboveground biomass tended to decrease with HS in both species (and for green leaf mass in S. canadensis), but decrease with +N for ,4. gerardii and increase with +N for S. canadensis. For A. gerardii, HS tended to decrease N% in green tissues with +N, whereas in S. canadensis, HS increased N% in green leaves.Added N decreased NRR for A. gerardii and HS increased NRR for S. canadensis. These results suggest that heat waves,though transient, could have significant effects on plants, communities, and ecosystem N cycling, and N can influence the effect of heat waves.

  10. Advances in processing technologies for titanium heat exchanger tubes of fossil and nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Likhareva, T.P.; Tchizhik, A.A.; Chavchanidze, N.N. [Polzanov Central Boiler and Turbine Institute, St. Petersburg (Russian Federation)

    1998-12-31

    The advances in processing technologies for titanium heat exchangers with rolled and welded tubes of fossil and nuclear power plants in Russia are presented. The special methodology of investigations with constant small strain rate have been used to study the effects of mixed corrosion and creep processes in condensers cooled by sea or synthetic sea waters. The results of corrosion creep tests and K1scc calculations are given. The Russian science activities concerning condensers manufactured from titanium show the possibilities for designing structures with very high level service reliability in different corrosion aggressive mediums with high total salt, Cl-ion and oxygen contents. (orig.)

  11. Optimisation of a Kalina cycle for a central receiver solar thermal power plant with direct steam generation

    DEFF Research Database (Denmark)

    Modi, Anish; Haglind, Fredrik

    2014-01-01

    Central receiver solar thermal power plants are regarded as one of the promising ways to generate electricity in near future. They offer the possibility of using high temperatures and pressures to achieve high efficiencies with standard power cycles. A direct steam generation approach can be used...... for a central receiver solar thermal power plant with direct steam generation. The variation in the cycle performance with respect to the turbine inlet ammonia mass fraction and pressure and a comparison of the initial investment with that of the basic Rankine cycle are also presented. Only high live steam...... for such plants for improved performance. This approach can also be combined with using advanced power cycles like the Kalina cycle, which uses a zeotropic mixture of ammonia and water instead of pure water as the working fluid. This paper presents the optimisation of a particular Kalina cycle layout...

  12. Palaeoclimate reconstruction within the upper Eocene in central Germany using fossil plants

    Science.gov (United States)

    Moraweck, Karolin; Kunzmann, Lutz; Uhl, Dieter; Kleber, Arno

    2013-04-01

    The Eocene has been commonly called "The world`s last greenhouse period" covering the Paleocene-Eocene Thermal Maximum (PETM) as well as the Eocene-Oligocene turnover. In the mid-latitudes of Europe this turnover was characterized by pronounced climatic changes from subtropical towards temperate conditions that were accompanied by significant vegetational changes on land. Fossil plants are regarded as excellent palaeoenvironmental proxies, because leaf physiognomy often reflects climate conditions. The study site, the Paleogene Weißelster basin in central Germany, including fluvial, estuarine and lacustrine deposits, provides several excellently preserved megafloras for reconstructions of terrestrial palaeoclimate. For our case study we used material from different stratigraphic horizons within the late Eocene Zeitz megafloral assemblage recovered from the open-cast mines of Profen and Schleenhain. These horizons cover a time interval of ca. 3 Ma. The Zeitz megafloral assemblage ("Florenkomplex") was characterized by mainly evergreen, notophyllous vegetation, consisting of warm-temperate to subtropical elements. Tropical species are present but very rare. To infer the regional climatic conditions and putative climate changes from these fossil plants we compare proxy data obtained by the application of standard methods for quantitative reconstruction of palaeoclimate data: the coexistence approach (CA), leaf margin analysis (LMA) and Climate Leaf Analysis Multivariate Program (CLAMP).Before the CA was applied to the material the list of putative nearest living relative species (NLR) was carefully revisited and partly revised. In case of the LMA approach information of so-called "silent taxa" (fossil species preserved by diaspores, leaf margin state is inferred from NLR data) were partly included in the data set. The four floras from the Zeitz megafloral assemblage show slightly different floral compositions caused by various taphonomic processes. An aim of the

  13. System studies of coal fired-closed cycle MHD for central station power plants

    Science.gov (United States)

    Zauderer, B.

    1976-01-01

    This paper presents a discussion of the closed cycle MHD results obtained in a recent study of various advanced energy conversion (ECAS) power systems. The study was part of the first phase of this ECAS study. Since this was the first opportunity to evaluate the coal fired closed cycle MHD system, a number of iterations were required to partially optimize the system. The present paper deals with the latter part of the study in which the direct coal fired, MHD topping-steam bottoming cycle was established as the current choice for central station power generation. The emphasis of the paper is on the background assumptions and the conclusions that can be drawn from the closed cycle MHD analysis. The author concludes that closed cycle MHD has efficiencies comparable to that of open cycle MHD and that both systems are considerably more efficient than the other system studies in Phase 1 of the GE ECAS. Its cost will possibly be slightly higher than that of the open cycle MHD system. Also, with reasonable fuel escalation assumptions, both systems can produce lower cost electricity than conventional steam power plants. Suggestions for further work in closed cycle MHD components and systems is made.

  14. Integral power evaluation in fossil fuel power plants; Evaluacion energetica integral en unidades de centrales termoelectricas

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa I, Luis R; Sanchez H, Laura E; Rodriguez M, Jose H [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Nebradt G, Jesus [Unidad de Investigacion y Desarrollo de la Subdireccion de Generacion de la Comision Federal de Electricidad, (Mexico)

    2006-07-01

    In this occasion, a methodology is presented that carries out an integral energy evaluation of fossil fuel power plants units (FFPPU) with the purpose of determining the root of the significant decrements of power produced soon after the annual maintenance service. This proposal, besides identifying the origin of the energy efficiency problems, offers information about the contributions of each one of the involved equipment in the total decrement of the unit. With this methodology, the maintenance focuses in the equipment that contributes to the greater energy loss. This document presents such methodology along with its application in a real case, results and necessary remedial actions, demonstrating that its application offers bases for the investment in corrective measures. [Spanish] En esta ocasion se presenta una metodologia que efectua una evaluacion energetica integral de las unidades de centrales termoelectricas (UCT) con el fin de determinar la raiz de los decrementos de potencia significativos producidos luego del servicio anual de mantenimiento. Dicha propuesta, ademas de identificar el origen de los problemas de eficiencia energetica, brinda informacion acerca de las aportaciones de cada uno de los equipos involucrados al decremento total de la unidad. Con esta metodologia, el mantenimiento se enfoca a los equipos que contribuyen a la mayor perdida de potencia. Este documento exhibe tal metodologia junto con su aplicacion en un caso real, resultados y las acciones correctivas necesarias, demostrando que su aplicacion ofrece bases para una inversion futura en medidas correctivas.

  15. Virucidal activity and chemical composition of essential oils from aromatic plants of central west Argentina.

    Science.gov (United States)

    García, Cybele C; Acosta, Eliana G; Carro, Ana C; Fernández Belmonte, María C; Bomben, Renata; Duschatzky, Claudia B; Perotti, Marina; Schuff, Carola; Damonte, Elsa B

    2010-08-01

    The essential oils of seven aromatic plants from central west Argentina were isolated by steam distillation and analyzed by a gas chromatography/mass spectrometry technique. The oils were screened for cytotoxicity and in vitro inhibitory activity against herpes simplex virus type 1 (HSV-1), dengue virus type 2 (DENV-2) and Junin virus (JUNV). The oils showed a variable virucidal action according to the virus. JUNV was the least susceptible virus in comparison with HSV-1 and DENV-2. The better relationship between cytotoxicity and inhibitory activity was observed for the essential oil of Lantana grisebachiii (Seckt.) var. grisebachii against DENV-2 and HSV-1 with IC50 (inhibitory concentration 50%) values of 21.1 and 26.1 ppm, respectively. This effect was specific since the selectivity indices (ratio cytotoxicity/virucidal activity) were > 23.7 and > 19.1 for DENV-2 and HSV-1, respectively. Furthermore, the oil from L. grisebachii was also an effective inhibitor of HSV-2 and acyclovir resistant variants of herpes virus. This study demonstrates the effective and selective inhibitory activity of the essential oil from Lantana grisebachii against HSV and DENV by direct virus inactivation. PMID:20839642

  16. The economic and environmental impacts of biofuel taxes on heating plants in Sweden

    International Nuclear Information System (INIS)

    Sweden's energy policy is currently based on a large-scale introduction of biofuels. Following a 1980 nuclear power referendum, the current plan is to phase out nuclear power, replacing nuclear energy with renewable energy sources. This policy is supported by various tax breaks for biofuels. There is an ongoing discussion about a restructuring of the energy tax system, which will have far-reaching impact on the markets for biofuels. This paper evaluates the impact of changes in current energy taxation by analyzing a panel of approximately 150 district heating plants in Sweden. We estimate plant-specific production functions and derive the economic repercussions of the tax. We also estimate the resulting changes of emissions of sulfur, NOX and particulates and assess the externality costs Arbetsrapport 258. 6 refs, 4 figs, 11 tabs

  17. Status of projects using reject heat for aquaculture and horticulture at power plants in the EEC

    International Nuclear Information System (INIS)

    Data collected mainly from an inventory of waste heat projects in the EEC prepared by Potentiel Energie of Paris covers 46 projects approximately half of which are fish farms and half horticultural projects mainly in the form of greenhouses. About a half of the projects are run on a commercial basis while the other half are Research and Development (R and D) or demonstrations. At least 18 species of fish and 18 species of plant are produced at the various projects but eels and potted plants are grown at more of the commercially orientated projects than any other produce. There has been a significant increase in the number of commercially run projects during the past 10-15 years and this trend is likely to continue in view of the considerable savings that can be made on fuel. The size and number of commercial projects in the UK compares favourably with those in other EEC countries. (author)

  18. Application of solar energy in heating and cooling of residential buildings under Central Asian conditions

    OpenAIRE

    Usmonov Shukhrat Zaurovich

    2014-01-01

    Solar radiation is the main source of thermal energy for almost all the processes developing in the atmosphere, hydrosphere, and biosphere. The total duration of sunshine in Tajikistan ranges from 2100 to 3170 hours per year. Solar collectors can be mounted on the roof of a house after its renovation and modernization. One square meter of surface area in Central Asia accounts for up to 1600 kW/h of solar energy gain, whilst the average gain is 1200 kW/h. Active solar thermal systems are able ...

  19. Occupants’ behavioural adaptation in workplaces with non-central heating and cooling systems

    International Nuclear Information System (INIS)

    Occupants’ behaviour when improving the indoor environment plays a significant role in saving energy in buildings. Therefore the key step to reducing energy consumption and carbon emissions from buildings is to understand how occupants interact with the environment they are exposed to in terms of achieving thermal comfort and well-being; though such interaction is complex. This paper presents a dynamic process of occupant behaviours involving technological, personal and psychological adaptations in response to varied thermal conditions based on the data covering four seasons gathered from the field study in Chongqing, China. It demonstrates that occupants are active players in environmental control and their adaptive responses are driven strongly by ambient thermal stimuli and vary from season to season and from time to time, even on the same day. Positive, dynamic, behavioural adaptation will help save energy used in heating and cooling buildings. However, when environmental parameters cannot fully satisfy occupants’ requirements, negative behaviours could conflict with energy saving. The survey revealed that about 23% of windows are partly open for fresh air when air-conditioners are in operation in summer. This paper addresses the issues how the building and environmental systems should be designed, operated and managed in a way that meets the requirements of energy efficiency without compromising wellbeing and productivity. - Highlights: ► A year-long field study of observing user behaviour in workplace. ► Occupants’ behavioural adaptation plays an important role in reducing energy from buildings. ► Occupants actively and dynamically respond to outdoor climate change. ► Positive behavioural adaptations will eliminate the use of heating/cooling facilities. ► The poor use of heating/cooling facilities will cause a significant waste of energy.

  20. Monitored performance of residential geothermal heat pumps in central Texas and Southern Michigan

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, W.N.

    1997-11-01

    This report summarizes measured performance of residential geothermal heat pumps (GHP`s) that were installed in family housing units at Ft. Hood, Texas and at Selfridge Air National Guard base in Michigan. These units were built as part of a joint Department of Defense/Department of Energy program to evaluate the energy savings potential of GHP`s installed at military facilities. At the Ft. Hood site, the GHP performance was compared to conventional forced air electric air conditioning and natural gas heating. At Selfridge, the homes under test were originally equipped with electric baseboard heat and no air conditioning. Installation of the GHP systems at both sites was straightforward but more problems and costs were incurred at Selfridge because of the need to install ductwork in the homes. The GHP`s at both sites produced impressive energy savings. These savings approached 40% for most of the homes tested. The low cost of energy on these bases relative to the incremental cost of the GHP conversions precludes rapid payback of the GHP`s from energy savings alone. Estimates based on simple payback (no inflation and no interest on capital) indicated payback times from 15 to 20 years at both sites. These payback times may be reduced by considering the additional savings possible due to reduced maintenance costs. Results are summarized in terms of 15 minute, hourly, monthly, and annual performance parameters. The results indicate that all the systems were working properly but several design shortcomings were identified. Recommendations are made for improvements in future installations at both sites.

  1. Results of the safety evaluation for the AVR-modification into a nuclear process heat plant

    International Nuclear Information System (INIS)

    In 1983 the Juelich Nuclear Research Center (KFA) proposed the modification of the AVR for high-temperature process heat systems demonstration. This would represent the achievement of an important HTR target. The work for the modification performed so far has given evidence that the plant will continue to run reliably and has led to an optimized plant concept. Most of the investigations were devoted to safety issues. The safety and licensing questions were discussed by an advisory group of the German Federal Ministry of the Interior which gave its vote in March 1985 and came to very positive conclusions. The AVR fulfils the current safety and licensing requirements; for the proposed plant modification no severe backfitting has to be taken into account. The AVR-building and the reactor itself turned out to be earthquake-proof, even according to current licensing demands if realistic site-specific earthquake spectra are applied. Risk assessment of an airplane crash show that the public risk is negligible even in the case of unrealistically pessimistic assumptions concerning the release of radioactivity. The modified plant will have a confinement similar to the modern German HTR-design. The investigations have shown that the safety questions related to a steam reformer in a primary circuit system are solved. All consequences of process gas release into the safety enclosure or into the primary system are controlled effectively by active and passive measures. Process gas release in the vicinity of the nuclear plant is excluded by the plant concept. Furthermore, even the hypothetical assumption of process gas explosions cannot damage the essential safety functions. (author)

  2. Optimal scheduling of industrial combined heat and power plants under time-sensitive electricity prices

    International Nuclear Information System (INIS)

    Combined heat and power (CHP) plants are widely used in industrial applications. In the aftermath of the recession, many of the associated production processes are under-utilized, which challenges the competitiveness of chemical companies. However, under-utilization can be a chance for tighter interaction with the power grid, which is in transition to the so-called smart grid, if the CHP plant can dynamically react to time-sensitive electricity prices. In this paper, we describe a generalized mode model on a component basis that addresses the operational optimization of industrial CHP plants. The mode formulation tracks the state of each plant component in a detailed manner and can account for different operating modes, e.g. fuel-switching for boilers and supplementary firing for gas turbines, and transitional behavior. Transitional behavior such as warm and cold start-ups, shutdowns and pre-computed start-up trajectories is modeled with modes as well. The feasible region of operation for each component is described based on input–output relationships that are thermodynamically sound, such as the Willans line for steam turbines. Furthermore, we emphasize the use of mathematically efficient logic constraints that allow solving the large-scale models fast. We provide an industrial case study and study the impact of different scenarios for under-utilization. - Highlights: • Unified representation for CHP plant components to capture flexibility in terms of thermodynamics and transitional behavior. • Efficient mathematical formulation for logic constraints that allows solving real-world case study in reasonable time. • Industrial case study shows economic benefit of 5–20% depending on level of utilization. • CHP plant's operating data allows readers to reproduce results and comparison with other model formulations

  3. Development of heat sink concept for near-term fusion power plant divertor

    International Nuclear Information System (INIS)

    The development of the efficient divertor concept is an important task to meet in the scenario of the future fusion power plant (DEMO). The divertor has to discharge the considerable fraction ∼15% of the total fusion thermal power incident on the divertor, therefore it has to survive very high thermal loads (∼10 MW/m2). In the present study, a new high efficient divertor heat sink (HEDHS) concept is proposed for the future post ITER tokamak called as 'DEMO'. The first wall of the diverter made-up of several modules to overcome the stresses caused by high heat flux, in the present design. Thermal hydraulic performance of one such HEDHS module is numerically investigated using the Fluent software. The effects of critical thermal hydraulic and geometric parameters on the heat transfer characteristics of HEDHS are presented with the Reynolds number (Re) range of 1.2 × 104 - 3.0 × 104. The stresses induced in the HEDHS by the thermal and pressure loads are an important factor that limits the performance and life of the divertor. Therefore, heat transfer coefficient received from the computational fluid dynamics (CFD) analysis is used to perform the thermo-mechanical analysis through finite element based approach. The result revealed that, the proposed design is capable to accommodate the design loads at the acceptable pumping power ratio, and stresses are well within the allowable limits. In addition, detailed of fluid flow and heat transfer mechanism associated with geometric variation have also been studied for the HEDHS to enhance the thermal performance. (author)

  4. Solar-assisted central heating in Hamburg-Bramfeld; Solarunterstuetzte Nahwaermeversorgung Hamburg-Bramfeld

    Energy Technology Data Exchange (ETDEWEB)

    Ebel, M. [HGC Hamburg Gas Consult, Hamburg (Germany)

    1998-12-31

    About 38% of the energy consumed in Germany is used for space heating. Hot water demand of old buildings accounts for approximately 10% while buildings constructed according to modern insulation standards account for 15 - 20 %. Space heating has a considerable conservation potential, which plays an important role in terms of reducing carbon dioxide pollution. More and more new technologies for conventional thermal insulation as well as for the active use of solar energy are being developed and will soon be commercially available. (orig.) [Deutsch] In der Bundesrepublik Deutschland werden ca. 38% des Energieverbrauches fuer die Waermeversorgung von Gebaeuden eingesetzt. Auf den Warmwasserbedarf entfallen davon ca. 10% bei Altbauten und 15-20% bei Wohngebaeuden nach den heute gueltigen Waermeschutzbestimmungen. Damit liegt im Bereich der Waemreversorgung von Gebaeuden ein erhebliches Einsparpotential, welches innerhalb der Diskussion ueber die CO{sub 2}-Problematik eine immer groessere Bedeutung erlangt. Neben einer Verbesserung der konventionellen Waermedaemmung der Gebaeude werden zunehmend Techniken der aktiven Solarenergienutzung zur Einsatzreife entwickelt. (orig.)

  5. Effects of vertically ribbed surface roughness on the forced convective heat losses in central receiver systems

    Science.gov (United States)

    Uhlig, Ralf; Frantz, Cathy; Fritsch, Andreas

    2016-05-01

    External receiver configurations are directly exposed to ambient wind. Therefore, a precise determination of the convective losses is a key factor in the prediction and evaluation of the efficiency of the solar absorbers. Based on several studies, the forced convective losses of external receivers are modeled using correlations for a roughened cylinder in a cross-flow of air. However at high wind velocities, the thermal efficiency measured during the Solar Two experiment was considerably lower than the efficiency predicted by these correlations. A detailed review of the available literature on the convective losses of external receivers has been made. Three CFD models of different level of detail have been developed to analyze the influence of the actual shape of the receiver and tower configuration, of the receiver shape and of the absorber panels on the forced convective heat transfer coefficients. The heat transfer coefficients deduced from the correlations have been compared to the results of the CFD simulations. In a final step the influence of both modeling approaches on the thermal efficiency of an external tubular receiver has been studied in a thermal FE model of the Solar Two receiver.

  6. The response of leaves to heat stress in tomato plants with source-sink modulated by growth regulators

    Directory of Open Access Journals (Sweden)

    Zofia Starck

    2014-02-01

    Full Text Available The response to heat stress was investigated in heat-sensitive, Roma V. F. and heat-tolerant, Robin, cultivars whose fruit growth was stimulated by NOA + GA3 , or NOA + GA3 + zeatin. The treated plants were compared with untreated control plant. In each of these series half of the plants were subjected to one or three cycles of heat stress. A single cycle of 38°/25°C day and night did not significantly affect either the respiration rate or chlorophyll content. In PGR-untreated intact cv. Roma, heat stress inhibited starch formation during the day and strongly depressed night export from the blades. High temperature depressed the night transport less in plants having a higher sink demand of fruits in plant treated with PGR. In this case the amount of substances available for export was much higher and both sugars and starch were more intensively remobilized at night. In intact Robin plants, PGR and heat stress much less affected sugar and starch content. High temperature diminished noctural starch remobilization only in the NOA + GA3 series. Leaf disc growth was evaluated as a measure of response to heat stress after elimination of the direct effect of fruit demands. One cycle of high temperature did not negatively affect the growth of leaf discs; it even caused thermal low growth activation in both cultivars. Three cycles of heat stress depressed leaf disc growth after short-term stimulation, especially in Roma plants. Immediately after 3-day heat stress, there was no response of discs to GA3 or zeatin added to the solution on which the discs were floated. Leaf disc growth of Robin control and NOA + GA3 series was very similar in plants from optimal temperature conditions. High temperature inhibited only disc growth of the NOA + GA3 series owing to depression of starch break-down, diminishing the pool of sugars. In contrast, leaf discs of Roma cv. excided from NOA + GA3 treated plants from the optimal temperature series, grew more intensively

  7. Thermodynamic Optimization of the Operative Parameters for the Heat Recovery in Combined Power Plants

    Directory of Open Access Journals (Sweden)

    Alessandro Franco

    2001-03-01

    Full Text Available

    For the combined power plants, the optimization of the heat recovery steam generator (HRSG is of particular interest in order to improve the efficiency of the heat recovery from turbine exhaust gas and to maximize the power production in the steam cycle. The thermodynamic optimization is the first step of a power plant design optimization process. The aim of this paper is to provide thermodynamic tools for the optimal selection of the operative parameters of the HRSG, starting from which a detailed optimization of its design variables can be carried out. For the thermodynamic analysis, the selected objective is the minimization of thermal exergy losses, taking into account only the irreversibility due to the temperature difference between the hot and cold streams. Various HRSG configurations have been analyzed, from the simpler, a single evaporator to the common configuration of two-pressure steam generator with five different sections.

    •  This paper was presented at the ECOS'00 Conference in Enschede, July 5-7, 2000

  8. Themoeconomic optimization of triple pressure heat recovery steam generator operating parameters for combined cycle plants

    Directory of Open Access Journals (Sweden)

    Mohammd Mohammed S.

    2015-01-01

    Full Text Available The aim of this work is to develop a method for optimization of operating parameters of a triple pressure heat recovery steam generator. Two types of optimization: (a thermodynamic and (b thermoeconomic were preformed. The purpose of the thermodynamic optimization is to maximize the efficiency of the plant. The selected objective for this purpose is minimization of the exergy destruction in the heat recovery steam generator (HRSG. The purpose of the thermoeconomic optimization is to decrease the production cost of electricity. Here, the total annual cost of HRSG, defined as a sum of annual values of the capital costs and the cost of the exergy destruction, is selected as the objective function. The optimal values of the most influencing variables are obtained by minimizing the objective function while satisfying a group of constraints. The optimization algorithm is developed and tested on a case of CCGT plant with complex configuration. Six operating parameters were subject of optimization: pressures and pinch point temperatures of every three (high, intermediate and low pressure steam stream in the HRSG. The influence of these variables on the objective function and production cost are investigated in detail. The differences between results of thermodynamic and the thermoeconomic optimization are discussed.

  9. Integration of solar process heat into an existing thermal desalination plant in Qatar

    Science.gov (United States)

    Dieckmann, S.; Krishnamoorthy, G.; Aboumadi, M.; Pandian, Y.; Dersch, J.; Krüger, D.; Al-Rasheed, A. S.; Krüger, J.; Ottenburger, U.

    2016-05-01

    The water supply of many countries in the Middle East relies mainly on water desalination. In Qatar, the water network is completely fed with water from desalination plants. One of these power and desalination plants is located in Ras Abu Fontas, 20 km south of the capital Doha. The heat required for thermal desalination is provided by steam which is generated in waste heat recovery boilers (HRB) connected to gas turbines. Additionally, gas fired boilers or auxiliary firing in the HRBs are used in order to decouple the water generation from the electricity generation. In Ras Abu Fontas some auxiliary boilers run 24/7 because the HRB capacity does not match the demand of the desalination units. This paper contains the techno-economic analysis of two large-scale commercial solar field options, which could reduce the fuel consumption significantly. Both options employ parabolic trough technology with a nominal saturated steam output of 350 t/h at 15 bar (198°C, 240 MW). The first option uses direct steam generation without storage while the second relies on common thermal oil in combination with a molten salt thermal storage with 6 hours full-load capacity. The economic benefit of the integration of solar power depends mainly on the cost of the fossil alternative, and thus the price (respectively opportunity costs) of natural gas. At a natural gas price of 8 US-/MMBtu the internal rate of return on equity (IRR) is expected at about 5%.

  10. Heat Exchanger Tube Inspection of Nuclear Power Plants using IRIS Technique

    International Nuclear Information System (INIS)

    Inspection of heat exchange tubing include steam generator of nuclear power plant mostly performed with eddy current method. Recently, various inspection technique is available such as remote field eddy current, flux leakage and ultrasonic methods. Each of these techniques has its merits and limitations. Electromagnetic techniques are very useful to locate areas of concern but sizing is hard because of the difficult interpretation of an electric signature. On the other hand, ultrasonic methods are very accurate in measuring wall loss damage, and are reliable for detecting cracks. Additionally ultrasound methods is not affected by support plates or tube sheets and variation of electrical conductivity or permeability. Ultrasound data is also easier to analyze since the data displayed is generally the remaining wall thickness. It should be emphasized that ultrasound is an important tool for sizing defects in tubing. In addition, it can be used in situations where eddy current or remote field eddy current is not reliable, or as a flaw assessment tool to supplement the electromagnetic data. The need to develop specialized ultrasonic tools for tubing inspection was necessary considering the limitations of electromagnetic techniques to some common inspection problems. These problems the sizing of wall loss in carbon steel tubes near the tube sheet or support plate, sizing internal erosion damage, and crack detection. This paper will present an IRIS(Internal Rotating Inspection System) ultrasonic tube inspection technique for heat exchanger tubing in nuclear power plant and verify inspection reliability for artificial flaw embedded to condenser tube

  11. District heat from the Beznau nuclear power plant - the first extension phase for Refuna now in operation

    International Nuclear Information System (INIS)

    Eleven months after the first orders for equipment for decoupling heat from the Beznau Nuclear Power Plant of the North East Swiss Power Company, the supply of district heat to two Federal Institutions, EIR in Wuerenlingen and SIN in Villingen, was commended on November, 15sup(th), 1983. Thus the first major stage in the construction of a regional district heating network in the lower Aare valley (Refuna) is complete. During the course of further extension additional communities and large consumers will be supplied with heat from Beznau. (orig.)

  12. Transgenic tobacco plants overexpressing a grass PpEXP1 gene exhibit enhanced tolerance to heat stress.

    Directory of Open Access Journals (Sweden)

    Qian Xu

    Full Text Available Heat stress is a detrimental abiotic stress limiting the growth of many plant species and is associated with various cellular and physiological damages. Expansins are a family of proteins which are known to play roles in regulating cell wall elongation and expansion, as well as other growth and developmental processes. The in vitro roles of expansins regulating plant heat tolerance are not well understood. The objectives of this study were to isolate and clone an expansin gene in a perennial grass species (Poa pratensis and to determine whether over-expression of expansin may improve plant heat tolerance. Tobacco (Nicotiana tabacum was used as the model plant for gene transformation and an expansin gene PpEXP1 from Poa pratensis was cloned. Sequence analysis showed PpEXP1 belonged to α-expansins and was closely related to two expansin genes in other perennial grass species (Festuca pratensis and Agrostis stolonifera as well as Triticum aestivum, Oryza sativa, and Brachypodium distachyon. Transgenic tobacco plants over-expressing PpEXP1 were generated through Agrobacterium-mediated transformation. Under heat stress (42°C in growth chambers, transgenic tobacco plants over-expressing the PpEXP1 gene exhibited a less structural damage to cells, lower electrolyte leakage, lower levels of membrane lipid peroxidation, and lower content of hydrogen peroxide, as well as higher chlorophyll content, net photosynthetic rate, relative water content, activity of antioxidant enzyme, and seed germination rates, compared to the wild-type plants. These results demonstrated the positive roles of PpEXP1 in enhancing plant tolerance to heat stress and the possibility of using expansins for genetic modification of cool-season perennial grasses in the development of heat-tolerant germplasm and cultivars.

  13. Transgenic tobacco plants overexpressing a grass PpEXP1 gene exhibit enhanced tolerance to heat stress.

    Science.gov (United States)

    Xu, Qian; Xu, Xiao; Shi, Yang; Xu, Jichen; Huang, Bingru

    2014-01-01

    Heat stress is a detrimental abiotic stress limiting the growth of many plant species and is associated with various cellular and physiological damages. Expansins are a family of proteins which are known to play roles in regulating cell wall elongation and expansion, as well as other growth and developmental processes. The in vitro roles of expansins regulating plant heat tolerance are not well understood. The objectives of this study were to isolate and clone an expansin gene in a perennial grass species (Poa pratensis) and to determine whether over-expression of expansin may improve plant heat tolerance. Tobacco (Nicotiana tabacum) was used as the model plant for gene transformation and an expansin gene PpEXP1 from Poa pratensis was cloned. Sequence analysis showed PpEXP1 belonged to α-expansins and was closely related to two expansin genes in other perennial grass species (Festuca pratensis and Agrostis stolonifera) as well as Triticum aestivum, Oryza sativa, and Brachypodium distachyon. Transgenic tobacco plants over-expressing PpEXP1 were generated through Agrobacterium-mediated transformation. Under heat stress (42°C) in growth chambers, transgenic tobacco plants over-expressing the PpEXP1 gene exhibited a less structural damage to cells, lower electrolyte leakage, lower levels of membrane lipid peroxidation, and lower content of hydrogen peroxide, as well as higher chlorophyll content, net photosynthetic rate, relative water content, activity of antioxidant enzyme, and seed germination rates, compared to the wild-type plants. These results demonstrated the positive roles of PpEXP1 in enhancing plant tolerance to heat stress and the possibility of using expansins for genetic modification of cool-season perennial grasses in the development of heat-tolerant germplasm and cultivars. PMID:25003197

  14. Nuclear Co-Generating Plants for Powering and Heating to Cleaning the Warsaw's Environment

    International Nuclear Information System (INIS)

    In 2009 the Polish Government made a decision to introduce nuclear power to Poland. Two nuclear power plants (NPPs) will be constructed nearly at the same time - the first unit should start operation in 2020, and by 2030 there should be about 6000 MWe added to the national electrical grid. The Commissioner of the Government was nominated to introduce the Polish Nuclear Power Program (PNPP). One of the four vertically integrated - the biggest energy company (PGE - the Polish Energy Group with headquarters in Warsaw) was appointed to prepare investments. These activities are planned in four stages: I. up to 31.12.2010 - The PNPP will be prepared and the program must then be accepted by the Government. II. 2011 - 2013 - Sites will be determined, and the contract for construction of the first NPP will be closed. III. 2014 - 2015 - Technical specifications will be prepared and accepted according the law. IV. 2016 - 2020 - The first NPP in Poland will be constructed. At present, the Government is receiving proposals from some regions of Poland asking that they be chosen for the NPP. One of the obvious locations for the NPP is a 40-kilometer vicinity of Warsaw (1.8 mln inhabitants). The need for both electric power and heat is increasing because of the rapidly growing town. It gives the extremely valuable chance for a very high thermodynamic efficiency of 80% in co-generation instead of 33% (max 36% for EPR-1600) for NPP generated electric power only. The Warsaw heating system has a capacity of 3950 MWt and is the biggest among EU countries. It is the third biggest in the world. Two NPPs, each of 2 x 1000 MWe could be built on the Vistula River up and down the town. In 2005, UE calculated losses caused by gas emissions at 24 mld eur, and the span of human lives was six months shorter in western countries and 8 months shorter in Poland. Warsaw's atmosphere is very polluted also because there are four heat and power generating plants: three coal and one oil -fired. In these

  15. Heat transfer and thermodynamic performance of a parabolic trough receiver with centrally placed perforated plate inserts

    International Nuclear Information System (INIS)

    Highlights: • Heat transfer enhancement of a parabolic trough receiver with perforated plate inserts is studied. • Effect of insert geometrical parameters on receiver thermal performance is investigated. • Correlations for Nusselt number and friction factor performance are derived and presented. • Performance evaluation using enhancement factors and collector modified thermal efficiency was demonstrated. • Thermodynamic performance is investigated using the entropy generation minimization method. - Abstract: In this paper, a numerical investigation of thermal and thermodynamic performance of a receiver for a parabolic trough solar collector with perforated plate inserts is presented. The analysis was carried out for different perforated plate geometrical parameters including dimensionless plate orientation angle, the dimensionless plate spacing, and the dimensionless plate diameter. The Reynolds number varies in the range 1.02 × 104 ⩽ Re ⩽ 7.38 × 105 depending on the heat transfer fluid temperature. The fluid temperatures used are 400 K, 500 K, 600 K and 650 K. The porosity of the plate was fixed at 0.65. The study shows that, for a given value of insert orientation, insert spacing and insert size, there is a range of Reynolds numbers for which the thermal performance of the receiver improves with the use of perforated plate inserts. In this range, the modified thermal efficiency increases between 1.2% and 8%. The thermodynamic performance of the receiver due to inclusion of perforated plate inserts is shown to improve for flow rates lower than 0.01205 m3/s. Receiver temperature gradients are shown to reduce with the use of inserts. Correlations for Nusselt number and friction factor were also derived and presented

  16. Experiments to investigate direct containment heating phenomena with scaled models of the Surry Nuclear Power Plant

    International Nuclear Information System (INIS)

    The Containment Technology Test Facility (CTTF) and the Surtsey Test Facility at Sandia National Laboratories are used to perform scaled experiments that simulate High Pressure Melt Ejection accidents in a nuclear power plant (NPP). These experiments are designed to investigate the effects of direct containment heating (DCH) phenomena on the containment load. High-temperature, chemically reactive melt (thermite) is ejected by high-pressure steam into a scale model of a reactor cavity. Debris is entrained by the steam blowdown into a containment model where specific phenomena, such as the effect of subcompartment structures, prototypic air/steam/hydrogen atmospheres, and hydrogen generation and combustion, can be studied. Four Integral Effects Tests (IETs) have been performed with scale models of the Surry NPP to investigate DCH phenomena. The 1/61th scale Integral Effects Tests (IET-9, IET-10, and IET-11) were conducted in CTRF, which is a 1/6th scale model of the Surry reactor containment building (RCB). The 1/10th scale IET test (IET-12) was performed in the Surtsey vessel, which had been configured as a 1/10th scale Surry RCB. Scale models were constructed in each of the facilities of the Surry structures, including the reactor pressure vessel, reactor support skirt, control rod drive missile shield, biological shield wall, cavity, instrument tunnel, residual heat removal platform and heat exchangers, seal table room and seal table, operating deck, and crane wall. This report describes these experiments and gives the results

  17. EXPERIMENTAL RESEARCH AND DESIGN ON HEAT TRANSFER OF EVAPORATOR USED IN THE LARGE QUICK FREEZE PLANT

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The evaporator is the main part of a quick-freeze equipment. There are many factors influencing the heat transfer coefficient of an evaporator. The most important factors among them are the fin shape, tube diameter, distance of fin space, frost, and velocity of air flow etc. They mainly influence the thermal efficiency of an evaporator, and therefore its thermal efficiency has direct relationship with the whole efficiency of the quick freeze plant. Evaporators with different structural types have different heat transfer efficiency. In order to obtain high efficiency structure of evaporator, 8 evaporator models with different fin shape, tube diameter and tube arrangement are analyzed and compared. The calculation results show that the integral waved fins, equilateral-triangle arranged small diameter tubes and varying fin-spacing has the highest heat transfer coefficient. The experimental result also shows that the evaporator with this type of structure has better thermal efficiency. The experimental result is in good agreement with the calculation result. It can instruct engineering design for usual designer. A real quick-freeze equipment is designed and put into production. The result shows that, compared with traditional domestic quick-freeze equipments, this equipment decreases by 40% in size and by 20% in energy consumption.

  18. Positive interactions between alpine plant species and the nurse cushion plant Laretia acaulis do not increase with elevation in the Andes of central Chile.

    Science.gov (United States)

    Cavieres, Lohengrin A; Badano, Ernesto I; Sierra-Almeida, Angela; Gómez-González, Susana; Molina-Montenegro, Marco A

    2006-01-01

    In alpine habitats, positive interactions among plants tend to increase with elevation as a result of altitudinal increase in environmental harshness. However, in mountains located in arid zones, lower elevations are also stressful because of scarce availability of water, suggesting that positive interactions may not necessarily increase with elevation. Here we analysed the spatial association of plant species with the nurse cushion plant Laretia acaulis at two contrasting elevations, and monitored the survival of seedlings of two species experimentally planted within and outside cushions in the semiarid Andes of central Chile. Positive spatial associations with cushions were more frequent at lower elevations. Species growing at the two elevations changed the nature of their association with cushions from neutral or negative at higher elevations to positive at lower elevations. Survival of seedlings was higher within cushions, particularly at lower elevations. The increased facilitation by cushions at lower elevations seems to be related to provision of moisture. This result suggests that cushion plants play a critical role in structuring alpine plant communities at lower elevations, and that climatic changes in rainfall could be very relevant for persistence of plant communities. PMID:16390419

  19. Effective heat transport of Gulf Stream to subarctic North Atlantic during Miocene cooling: evidence from "Köppen signatures" of fossil plant assemblages

    Directory of Open Access Journals (Sweden)

    T. Denk

    2013-08-01

    Full Text Available Shallowing of the Panama Sill and the closure of the Central American Seaway initiated the modern Loop Current/Gulf Stream circulation pattern during the Miocene but no direct evidence has yet been provided for effective heat transport to the northern North Atlantic during that time. Climatic signals from 11 precisely-dated plant-bearing sedimentary rock formations in Iceland, spanning 15–0.8 million years (Myr, resolve the impacts of the developing Miocene global thermohaline circulation on terrestrial vegetation in the subarctic North Atlantic region. "Köppen signatures" were implemented to express climatic properties of fossil plant taxa and their potential modern analogues using the principal concept of the generic Köppen–Geiger climate system, which is based on plant distribution patterns. Using Köppen signatures and the correlation between Köppen climate zones and major global vegetation zones, fossil assemblages were used to trace major vegetation shifts. This evidence was combined with evidence from tectonics and palaeoceanography. In contrast to the global climatic trend, the vegetation record reveals no cooling between ~ 15 and 12 Myr, whereas periods of climatic deterioration between 12–10 Myr, 8–4 Myr, and in the Pleistocene are in phase with increased pulses of ice-rafted debris in the Northern Hemisphere. The observed sequence of climate change in the northern North Atlantic can only be explained by an effective Gulf Stream-mediated heat transport from the middle Miocene onwards.

  20. Relationship between Aflatoxin Contamination and Physiological Responses of Corn Plants under Drought and Heat Stress

    Directory of Open Access Journals (Sweden)

    Nacer Bellaloui

    2012-11-01

    Full Text Available Increased aflatoxin contamination in corn by the fungus Aspergillus flavus is associated with frequent periods of drought and heat stress during the reproductive stages of the plants. The objective of this study was to evaluate the relationship between aflatoxin contamination and physiological responses of corn plants under drought and heat stress. The study was conducted in Stoneville, MS, USA under irrigated and non-irrigated conditions. Five commercial hybrids, P31G70, P33F87, P32B34, P31B13 and DKC63-42 and two inbred germplasm lines, PI 639055 and PI 489361, were evaluated. The plants were inoculated with Aspergillus flavus (K-54 at mid-silk stage, and aflatoxin contamination was determined on the kernels at harvest. Several physiological measurements which are indicators of stress response were determined. The results suggested that PI 639055, PI 489361 and hybrid DKC63-42 were more sensitive to drought and high temperature stress in the non-irrigated plots and P31G70 was the most tolerant among all the genotypes. Aflatoxin contamination was the highest in DKC63-42 and PI 489361 but significantly lower in P31G70. However, PI 639055, which is an aflatoxin resistant germplasm, had the lowest aflatoxin contamination, even though it was one of the most stressed genotypes. Possible reasons for these differences are discussed. These results suggested that the physiological responses were associated with the level of aflatoxin contamination in all the genotypes, except PI 639055. These and other physiological responses related to stress may help examine differences among corn genotypes in aflatoxin contamination.