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 performance with other control strategies and made proposals for furher enhancements....

  4. Central Heating Plant site characterization report, Marine Corps Combat Development Command, Quantico, Virginia

    Energy Technology Data Exchange (ETDEWEB)

    1990-08-01

    This report presents the methodology and results of a characterization of the operation and maintenance (O M) environment at the US Marine Corps (USMC) Quantico, Virginia, Central Heating Plant (CHP). This characterization is part of a program intended to provide the O M staff with a computerized artificial intelligence (AI) decision support system that will assist the plant staff in more efficient operation of their plant. 3 refs., 12 figs.

  5. Enhancement of central heating plant economic evaluation program for retrofit to coal. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kinast, J.J.; Biederman, R.; Blazek, C.F.; Lin, M.C.; Moshagge, R.E.

    1994-09-01

    Public Law 99-190 requires the Department of Defense (DOD) to increase the use of coal for steam generation. However, DOD also has an obligation to use the most economical fuel. Supporting the coal conversion effort, the U.S. Army Construction Engineering Research Laboratories (USACERL) has developed a computer program for engineering personnel at Major Army Commands, installations, the Defense Logistics Agency, and other DOD facilities to analyze the technical and economic feasibility of specific coal-combustion technologies at central heating plant facilities on military bases. The program, Central Heating Plant Economic Evaluation (CHPECON), can model plants that have a capacity of 50,000 to 600,000 MBtu/hr of steam, with individual boiler sizes from 25,000 to 200,000 MBtu/hr. The technologies examined include coal-fired stoker and fluidized-bed boilers, oil/natural gas boilers, and coal-slurry boilers. This report documents enhancements to existing CHPECON procedures for analyzing the retrofit or reconversion of a central heating plant to coal firing. They include: improving the screening and scoring process for boiler facilities considered for retrofit; adding options for converting a facility back to coal firing; detailing retrofit costs; upgrading economic analysis of a retrofit from an operating cost evaluation to a life-cycle cost analysis; and expanding the economic analysis to include examination of the condition of existing equipment.

  6. Heat deposition into the superconducting central column of a spherical tokamak fusion plant

    Science.gov (United States)

    Windsor, C. G.; Morgan, J. G.; Buxton, P. F.

    2015-02-01

    A key challenge in designing a fusion power plant is to manage the heat deposition into the central core containing superconducting toroidal field coils. Spherical tokamaks have limited space for shielding the central core from fast neutrons produced by fusion and the resulting gamma rays. This paper reports a series of three-dimensional computations using the Monte Carlo N-particle code to calculate the heat deposition into the superconducting core. For a given fusion power, this is considered as a function of plasma major radius R0, core radius rsc and shield thickness d. Computations over the ranges 0.6 m ⩽ R0 ⩽ 1.6 m, 0.15 m ⩽ rsc ⩽ 0.25 m and 0.15 m ⩽ d ⩽ 0.4 m are presented. The deposited power shows an exponential dependence on all three variables to within around 2%. The additional effects of source profile, the outer shield and shield material are all considered. The results can be interpolated to 2% accuracy and have been successfully incorporated into a system code. A possible pilot plant with 174 MW of fusion is shown to lead to a heat deposition into the superconducting core of order 30 kW. An estimate of 1.7 MW is made for the cryogenic plant power necessary for heat removal, and of 88 s running time for an adiabatic experiment where the heat deposition is absorbed by a 10 K temperature rise.

  7. Central heating plant economic evaluation program. Volume 4. Coalfield properties information data management program. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lin, M.C.; Moshage, R.; Schanche, G.; Blazek, C.; Biederman, R.

    1995-01-01

    Public law has directed the Department of Defense (DoD) to rehabilitate and convert its existing domestic power plants to burn more coal. Other Federal legislation requires DoD to use the most economic fuel for any new heating system. This five-volume report discusses the Central Heating Plant Economic Evaluation Program (CHPECON), a computer program for screening potential new and retrofit steam/power generation facilities. Volume 4 is the Coalfield Properties Information Data Management Program. CHPECON provides screening criteria to evaluate competing combustion technologies using coal, gas, or oil; detailed conceptual facility design information; budgetary facility costs; and economic measures of project acceptability including total life cycle costs and levelized cost of service. The program provides sufficient flexibility to vary critical design and operating parameters to determine project sensitivity and parametric evaluation.

  8. Central heating plant economic evaluation program. Volume 2. User`s manual. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lin, M.C.; Moshage, R.; Schanche, G.; Blazek, C.; Biederman, R.

    1995-01-01

    Public Law has directed the Department of Defense (DOD) to rehabilitate and convert its existing domestic power plants to burn more coal. Other Federal legislation requires DOD to use the most economic fuel for any new heating system. This five-volume report discusses the Central Heating Plant Economic Evaluation Program (CHPECON), a computer program for screening potential new and retrofit steam/power generation facilities. Volume 1 is the Technical Reference. Volume 2 is the User`s Manual. Volume 3 is the Military Base Weather Information Data Management Program. Volume 4 is the Coalfield Properties Information Data Management Program. Volume 5 is the Emission Regulations Data Management Program. CHPECON provides screening criteria to evaluate competing combustion technologies using coal, gas, or oil; detailed conceptual facility design information; budgetary facility costs; and economic measures of project acceptability including total life cycle costs and levelized cost of service. The program provides sufficient flexibility to vary critical design and operating parameters to determine project sensitivity and parametric evaluation.

  9. Central heating plant economic evaluation program. Volume 5. Emission regulations data management program. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lin, M.C.; Moshage, R.; Schanche, G.; Blazek, C.; Biederman, R.

    1995-01-01

    Public Law has directed the Department of Defense (DOD) to rehabilitate and convert its existing domestic power plants to burn more coal. Other Federal legislation requires DOD to use the most economic fuel for any new heating system. This five-volume report discusses the Central Heating Plant Economic Evaluation Program (CHPECON), a computer program for screening potential new and retrofit steam/power generation facilities. Volume 1 is the Technical Reference. Volume 2 is the User`s Manual. Volume 3 is the Military Base Weather Information Data Management Program. Volume 4 is the Coalfield Properties Information Data Management Program. Volume 5 is the Emission Regulations Data Management Program. CHPECON provides screening criteria to evaluate competing combustion technologies using coal, gas, or oil; detailed conceptual facility design information; budgetary facility costs; and economic measures of project acceptability including total life cycle costs and levelized cost of service. The program provides sufficient flexibility to vary critical design and operating parameters to determine project sensitivity and parametric evaluation.

  10. The production of hot sanitary water by condensing boilers: Analysis of the seasonal experimental results of a central heating plant

    Energy Technology Data Exchange (ETDEWEB)

    Caliari, R.; Cirillo, E.; Lazzarin, R.; Piccininni, F.

    1988-12-01

    The use of condensing boilers in the production of hot sanitary water clearly evidences their advantages, since the highest operating temperatures are only around 60/degree/C. This paper examines performance test results relevant to a central heating plant (serving a residential area in Rovereto, Italy) with 112 kW of thermal power. The analysis reveals the excellent performance characteristics of the condensing boilers and points out the importance of proper management of the recirculation system.

  11. Do heat and smoke increase emergence of exotic and native plants in the matorral of central Chile?

    Science.gov (United States)

    Figueroa, Javier A.; Cavieres, Lohengrin A.; Gómez-González, Susana; Montenegro, Marco Molina; Jaksic, Fabian M.

    2009-03-01

    We studied the effect of heat shock and wood-fueled smoke on the emergence of native and exotic plant species in soil samples obtained in an evergreen shrubland of central Chile, located on the eastern foothills of the Coastal Range of Lampa. Immediately after collection samples were dried and stored under laboratory condition. For each two transect, 10 samples were randomly chosen, and one of the following treatments was applied: 1) Heat-shock treatment. 2) Plant-produced smoke treatment. 3) Combined heat-and-smoke treatment. 4) Control, corresponding to samples not subjected to treatment. Twenty-three species, representing 12 families, emerged from the soil samples. The best-represented families were Poaceae and Asteraceae. All of the emerged species were herbs, 21 were annuals, and 14 were exotic to Chile. Fire-related triggers used in this study did not increase the emergence and/or abundance of exotic species with respect to natives in soil samples. Interestingly, this study provides evidence that heat-shock can increase the emergence of native herbs.

  12. Central heating plant economic evaluation program. Volume 3. Military base weather information data management program. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lin, M.C.; Moshage, R.; Schanche, G.; Blazek, C.; Biederman, R.

    1995-01-01

    Public Law has directed the Department of Defense (DOD) to rehabilitate and convert its existing domestic power plants to burn more coal. Other Federal legislation requires DOD to use the most economic fuel for any new heating system. This five-volume report discusses the Central Heating Plant Economic Evaluation Program (CHPECON), a computer program for screening potential new and retrofit steam/power generation facilities. Volume 1 is the Technical Reference. Volume 2 is the User`s Manual. Volume 3 is the Military Base Weather Information Data Management Program. Volume 4 is the Coalfield Properties Information Data Management Program. Volume 5 is the Emission Regulations Data Management Program. CHPECON provides screening criteria to evaluate competing combustion technologies using coal, gas, or oil; detailed conceptual facility design information; budgetary facility costs; and economic measures of project acceptability including total life cycle costs and levelized cost of service. The program provides sufficient flexibility to vary critical design and operating parameters to determine project sensitivity and parametric evaluation.

  13. 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.

  14. Screening and life-cycle cost models for new pulverized-coal heating plants: An integrated computer-based module for the central heating plant economic evaluation program (CHPECON). Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, R.; Kinast, J.A.; Biederman, R.; Blazek, C.F.; Lin, M.C.

    1995-07-01

    Public Law 99-190 requires the Department of Defense (DOD) to increase the use of coal for steam generation, but DOD also has an obligation to use the most economical fuel. In support of the coal conversion effort, the U.S. Army Construction Engineering Research Laboratories (USACERL) has been tasked to develop a series of screening and life-cycle cost models to determine when and where specific coal-combustion technologies can economically be implemented in Army central heating plants. This report documents a pulverized coal-fired boiler analysis model, part of the USACERL-developed Central Heating Plant Economics model (CHPECON). The model is divided into two parts. A preliminary screening model contains options for evaluating new heating plants and cogeneration facilities fueled with pulverized coal, as well as the previous options. A cost model uses the entries provided by the screening model to provide a conceptual facility design, capital (installed) costs of the facility, operation and maintenance costs over the life of the facility, and life-cycle costs. Using these numbers the model produces a summary value for the total life-cycle cost of the plant, and a levelized cost of service.

  15. 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

  16. Stochastic modelling of central heating systems

    DEFF Research Database (Denmark)

    Hansen, Lars Henrik

    1997-01-01

    and the degree Erhvervsforsker (a special Danish degree, equivalent to ``Industrial Ph.D.''). The thesis is mainly concerned with experimental design and system identification for individual components in water based central heating systems. The main contribution to this field is on the nonlinear dynamic...

  17. 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

  18. 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

  19. 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.

  20. 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

  1. 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

  2. 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

  3. 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 ...

  4. Economics of installation of solar heating plants

    Science.gov (United States)

    Popel, O. S.; Frid, S. Y.; Shpiltayn, E. E.

    1984-04-01

    An engineering-economic analysis of solar heating plants for determination of their cost effectiveness involves calculating the maximum economically feasibile extra capital investment on their installation and calculating the fraction of the total heat demand covered by such a plant which makes replacement of conventional heating plant maximally economical. The annual economic effect of solar heating is calculated in terms of normalized cost differential, as criterion for its competitiveness with conventional heating. Plant performance characteristics, namely dependence of both the percent demand coverage and the annual cost differential on the area of solar radiation collectors is then considered. Analysis of the cost equation, assuming that the extra fixed cost is proportional to the collector area, reveals the necessary and sufficient condition for decrease of annual operating cost.

  5. 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

  6. 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.

  7. 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 ...

  8. 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)

  9. Indoor air pollution by different heating systems: coal burning, open fireplace and central heating.

    Science.gov (United States)

    Moriske, H J; Drews, M; Ebert, G; Menk, G; Scheller, C; Schöndube, M; Konieczny, L

    1996-11-01

    Investigations of indoor air pollution by different heating systems in private homes are described. Sixteen homes, 7 with coal burning, 1 with open fireplace (wood burning) and 8 with central heating have been investigated. We measured the concentrations of carbon monoxide, carbon dioxide and sedimented dust in indoor air, of total suspended particulates, heavy metals and of polycyclic aromatic hydrocarbons in indoor and outdoor air. Measurements were taken during winter (heating period) and during summer (non-heating period). Generally, we found higher indoor air pollution in homes with coal burning and open fireplace than in homes with central heating. Especially, the concentrations of carbon monoxide, sedimented dust and of some heavy metals were higher. In one case, we found also high indoor air pollution in a home with central heating. This apartment is on the ground floor of a block of flats, and the central heating system in the basement showed a malfunctioning of the exhaust system.

  10. 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...

  11. Energy analysis of a central domestic hot water heating system equipped with condensing boilers

    Energy Technology Data Exchange (ETDEWEB)

    Cirillo, E.; Lazzarin, R.; Piccininni, F. (Bologna Univ. (Italy). Ist. di Fisica); Caliari, R. (Servizio Energia, Provincia Autonoma di Trento (IT))

    1990-01-01

    An experimental study was carried out on a central plant for the heating of domestic hot water for a block of 143 flats and 15 offices. The behaviour of the condensing boilers serving the plant was examined and the energy costs of recirculation and distribution were analysed. Since the losses due to recirculation are of the same order as the useful energy, the influence of the various parameters on the losses has been studied, and some methods of lowering them are proposed. (author).

  12. 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.

  13. Changes in the timing, length and heating degree days of the heating season in central heating zone of China.

    Science.gov (United States)

    Shen, Xiangjin; Liu, Binhui

    2016-01-01

    Climate change affects the demand for energy consumption, especially for heating and cooling buildings. Using daily mean temperature (Tmean) data, this study analyzed the spatiotemporal changes of the starting date for heating (HS), ending date for heating (HE), length (HL) and heating degree day (HDD) of the heating season in central heating zone of China. Over China's central heating zone, regional average HS has become later by 0.97 day per decade and HE has become earlier by 1.49 days per decade during 1960-2011, resulting in a decline of HL (-2.47 days/decade). Regional averaged HDD decreased significantly by 63.22 °C/decade, which implies a decreasing energy demand for heating over the central heating zone of China. Spatially, there are generally larger energy-saving rate in the south, due to low average HDD during the heating season. Over China's central heating zone, Tmean had a greater effect on HL in warm localities and a greater effect on HDD in cold localities. We project that the sensitivity of HL (HDD) to temperature change will increase (decrease) in a warmer climate. These opposite sensitivities should be considered when we want to predict the effects of climate change on heating energy consumption in China in the future. PMID:27651063

  14. 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。

  15. 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.)

  16. 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.

  17. 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.)

  18. 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.)

  19. 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)

  20. Enhancement of reproductive heat tolerance in plants.

    Directory of Open Access Journals (Sweden)

    John J Burke

    Full Text Available Comparison of average crop yields with reported record yields has shown that major crops exhibit annual average yields three- to seven-fold lower than record yields because of unfavorable environments. The current study investigated the enhancement of pollen heat tolerance through expressing an Arabidopsis thaliana heat shock protein 101 (AtHSP101 that is not normally expressed in pollen but reported to play a crucial role in vegetative thermotolerance. The AtHSP101 construct under the control of the constitutive ocs/mas 'superpromoter' was transformed into cotton Coker 312 and tobacco SRI lines via Agrobacterium mediated transformation. Thermotolerance of pollen was evaluated by in vitro pollen germination studies. Comparing with those of wild type and transgenic null lines, pollen from AtHSP101 transgenic tobacco and cotton lines exhibited significantly higher germination rate and much greater pollen tube elongation under elevated temperatures or after a heat exposure. In addition, significant increases in boll set and seed numbers were also observed in transgenic cotton lines exposed to elevated day and night temperatures in both greenhouse and field studies. The results of this study suggest that enhancing heat tolerance of reproductive tissues in plant holds promise in the development of crops with improved yield production and yield sustainability in unfavorable environments.

  1. 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...

  2. 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...... 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...... and the economic perspectives, the results suggest that it is not beneficial to use the Kalina cycle for high temperature concentrating solar power plants....

  3. 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.

  4. 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.

  5. 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

  6. 77 FR 8178 - Test Procedures for Central Air Conditioners and Heat Pumps: Public Meeting

    Science.gov (United States)

    2012-02-14

    ...; ] DEPARTMENT OF ENERGY 10 CFR Part 430 Test Procedures for Central Air Conditioners and Heat Pumps: Public... discuss methodologies and gather comments on testing residential central air conditioners and heat pumps... residential central air conditioners and heat pumps that are single phase with rated cooling capacities...

  7. 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.

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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)

  13. 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.

  14. 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.

  15. Effects of passive heating on central blood volume and ventricular dimensions in humans

    DEFF Research Database (Denmark)

    Crandall, C.G.; Wilson, T.E.; Marving, J.;

    2008-01-01

    Mixed findings regarding the effects of whole-body heat stress on central blood volume have been reported. This study evaluated the hypothesis that heat stress reduces central blood volume and alters blood volume distribution. Ten healthy experimental and seven healthy time control (i.e. non-heat...... plus central vasculature (17 +/- 2%), thorax (14 +/- 2%), inferior vena cava (23 +/- 2%) and liver (23 +/- 2%) (all P Udgivelsesdato: 2008/1/1...

  16. 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

  17. 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.

  18. 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.

  19. 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 ...

  20. 两种利用电厂热量采暖供热的方案比较%Comparison of Two Heating Programs by Using Power Plant Heat

    Institute of Scientific and Technical Information of China (English)

    林俊光; 任渊源; 张卫灵; 崔云素

    2013-01-01

    发电厂有大量的低温余热被浪费,而通过热泵则可以将发电厂循环水的余热回收利用,从而提高热利用效率。基于热泵技术提出了一种汽水双热源供热量可调的集中供热系统,并与常规热电厂供热系统进行对比,认为利用热泵回收发电厂余热具有节能、环保的双重效应。虽然汽水双热源供热量可调集中供热系统的初投资较高,但运行费用较低,仅需3年就可收回投资。%A great deal of low-temperature residual heat is wasted in power plant. Recycling the residual heat of circulating water by heat pump could increase the efficiency of heat utilization. The paper proposes a cen-tral heating system with steam and water heat sources and heat adjustability on the basis of heat pump tech-nology and it compares the central heating system with the conventional heating system in thermal power plants. The paper believes that residual heat recycling by heat pump can save the energy and protect the en-vironment. Though the investment in central heating system with steam and water heat sources and heat ad-justability is high, the cost for operation is lower, and the investment can be returned in three years.

  1. Success factors for bioenergy production plants in district heating networks; Erfolgsfaktoren fuer Bioenergieanlagen mit Nahwaermenetz am Beispiel evaluierter Biomasseheizwerke

    Energy Technology Data Exchange (ETDEWEB)

    Leuchtweis, Christian [C.A.R.M.E.N. e.V., Straubing (Germany)

    2009-07-01

    Operators of heat supply plants who receive funds from the Bavarian State Ministry for Nutrition, Agriculture and Forestry are obliged to report annually on the operation of their heat supply plants over a period of up to twelve years (formerly five or seven years). For this purpose C.A.R.M.E.N. (Central Agricultural Resource Marketing and Energy Network) has compiled an extensive database which makes it possible to study the results from different perspectives.

  2. 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)

  3. 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.

  4. 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.

  5. Investigation of bubble behaviours in wet central heating systems

    Science.gov (United States)

    Shefik, Ali; Ge, Yunting

    2014-03-01

    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 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.

  6. 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.

  7. 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

  8. 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 improvements...... of the cost/performance ratio for solar collector fields, both with flat plate collectors and with concentrating tracking solar collectors. It is recommended to continue monitoring and analysis of all large solar heating plants to document the reliability of the solar heating plants. It is also recommended...

  9. 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

  10. 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.

  11. 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.

  12. Central heating pipes cause unwanted heating; CV-leidingen zorgen voor ongewenste opwarming

    Energy Technology Data Exchange (ETDEWEB)

    Wessels, R. [biq-stadsontwerp, Rotterdam (Netherlands); Nuijten, O. [ISSO, Rotterdam (Netherlands)

    2011-12-15

    Research has shown that the risk of hot spots in the drinking water pipes is very high. Hot spots are, for example, caused by central heating pipes that are too close to the water pipes. The water pipes may be 25 C for a long period, thus creating the risk of legionella growth. The various disciplines need to be careful in the design stage and building stage to prevent such situations from occurring. [Dutch] Onderzoek heeft uitgewezen dat het risico op 'hotspots' in de drinkwaterleidingen erg groot is. Hotspots worden bijvoorbeeld veroorzaakt door cv-leidingen die te dicht in de buurt van waterleidingen lopen. Die waterleidingen kunnen dan langdurig warmer zijn dan 25C en daardoor gevaar opleveren voor legionellagroei. Het vereist zorg van meerdere disciplines in de ontwerpfase en de bouwfase om deze situaties te vermijden.

  13. 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...

  14. 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.

  15. 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

  16. Cepload: A load-allocation program for army central energy plants. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Dilks, C.; Moshage, R.; Kinast, J.A.; Biederman, R.; Blazek, C.F.

    1994-09-01

    Significant energy savings may be achieved through improved coordination of boiler operation in Army central energy plants. Historically, plant operators have tended to run their facilities conservatively to cover the uncertainty of imminent loads while ensuring the reliability of the plant. Because a properly adjusted boiler`s operating efficiency depends primarily on its current load, and because most boilers produce their peak efficiencies in the range of 80 percent to 100 percent of their rated capacity, a preferred operating method would maintain each boiler`s load as close as possible to the point of maximum efficiency. Most Army heating and cooling loads are related to the weather. An accurate forecast of loads into the near future should make it possible to adjust the boilers to handle those loads more efficiently. Given a reliable forecast model for future loads and an evaluation of boiler operating parameters, an optimum boiler load allocation strategy may be developed. Such a strategy could help the Army improve energy efficiency and reduce the operating costs. The overall objective of this research is to develop a computer-based expert system to help central energy plant personnel optimize boiler operations based on accurate load forecasts. This report documents the development of an accurate load-forecasting model and a prototype expert system called CEPLOAD, which can use the model to help energy plant personnel optimize boiler load allocation.

  17. 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.

  18. Performance analysis of heating plants equipped with condensing boilers

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, R.M.; Schibuola, L.

    1986-01-01

    The behaviour of the condensing boilers is strictly bound to the temperature of the water coming back from the plant. This temperature depends on the control modes and on the meteorological conditions. The seasonal performance has been computed for a heating plant of a building equipped with a condensing boiler simulating the load at short time intervals through a suitable modification of TRNSYS. The study has been carried out in the climate of Padova. For other towns a rough estimate is proposed.

  19. 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.

  20. 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.

  1. 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

  2. Comparison of multitank storage DHW heating solar plants

    Energy Technology Data Exchange (ETDEWEB)

    Lazzarin, R.; Rossetto, L.; Schibuola, L.

    1983-04-01

    Distribution of the hot storage in a multitank system may be a suitable way to assure stratification in DHW solar heating plants of medium and great sizes. The possible connections for the various tanks are manifold: three different working ways are considered in this paper. Performances are analyzed during one year through TRNSYS computing program and the results are compared.

  3. 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...

  4. 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...

  5. 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

  6. Chloroplast retrograde regulation of heat stress responses in plants

    Directory of Open Access Journals (Sweden)

    Ai-Zhen eSun

    2016-03-01

    Full Text Available 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 primary susceptible 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. Such diverse metabolic and biosynthetic functions require efficient communication between plastids and the nucleus. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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...

  11. 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.

  12. 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

  13. 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...

  14. 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 ...

  15. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-11-01

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

  17. 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)

  18. Thermal energy storage heat exchanger: Molten salt heat exchanger design for utility power plants

    Science.gov (United States)

    Ferarra, A.; Yenetchi, G.; Haslett, R.; Kosson, R.

    1977-01-01

    The use of thermal energy storage (TES) in the latent heat of molten salts as a means of conserving fossil fuels and lowering the cost of electric power was evaluated. Public utility systems provided electric power on demand. This demand is generally maximum during late weekday afternoons, with considerably lower overnight and weekend loads. Typically, the average demand is only 60% to 80% of peak load. As peak load increases, the present practice is to purchase power from other grid facilities or to bring older less efficient fossil-fuel plants on line which increase the cost of electric power. The widespread use of oil-fired boilers, gas turbine and diesel equipment to meet peaking loads depletes our oil-based energy resources. Heat exchangers utilizing molten salts can be used to level the energy consumption curve. The study begins with a demand analysis and the consideration of several existing modern fossil-fuel and nuclear power plants for use as models. Salts are evaluated for thermodynamic, economic, corrosive, and safety characteristics. Heat exchanger concepts are explored and heat exchanger designs are conceived. Finally, the economics of TES conversions in existing plants and new construction is analyzed. The study concluded that TES is feasible in electric power generation. Substantial data are presented for TES design, and reference material for further investigation of techniques is included.

  19. 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

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

    DEFF Research Database (Denmark)

    Andersen, Palle; Pedersen, Tom Søndergaard; Stoustrup, Jakob;

    2000-01-01

    In central heating systems with thermostatic valve temperature control it is a well known fact that room temperature oscillations may occur when the heat demand becomes low due to the non-linear behavior of the control loop. This is not only discomforting but it also increases the energy cost...... of 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...

  1. 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.

  2. New integrated gas turbine CHP (combined heat and power) and incinerator plant.

    Science.gov (United States)

    Briggs, R A; Yates, B

    1990-12-01

    Despite the complex nature of the project, the clients brief of a 14 month design and installation period was achieved within the approved budget of 2.5 million pounds. Early performance figures indicate that the scheme is on target to achieve the original payback of under four years. Queen Elizabeth Hospital: installation of integrated combined heat and power plant. Client: Central Birmingham Health Authority. Consulting Engineers/Project Managers: Yates, Edge and Partners. Architects: Temple Cox and Nichols. Structural Engineers: Peel and Fowler. Quantity Surveyor: West Midlands Regional Health Authority.

  3. 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.

  4. 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.

  5. First Experience from the World Largest fully commercial Solar Heating Plant

    DEFF Research Database (Denmark)

    Heller, Alfred; Furbo, Simon

    1997-01-01

    The first experience from the largest solar heating plant in the world is given. The plant is situated in Marstal and is has a total area of 8000 square m.......The first experience from the largest solar heating plant in the world is given. The plant is situated in Marstal and is has a total area of 8000 square m....

  6. 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.

  7. 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

  8. 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.

  9. Exhaust gas side corrosion of oil fired central heating boilers

    Energy Technology Data Exchange (ETDEWEB)

    Koebel, M.; Elsener, M.

    1987-09-01

    While Swiss boiler producers aim primarily at achieving low exhaust gas temperatures, in our northern neighbouring country, lower boiler water temperatures are being set as favourite objectives to be met. The first method aims at reducing the exhaust gas losses, i.e. of the heat content of the exhaust gases; the second one aims at reducing service life losses (= losses in the off-air of the boiler). Flue-gas caused corrosion, however, sets practical limits to the energy-saving reduction of the exhaust gas and boiler water temperatures. To be able to define this practical limit more exactly is the main goal of this project which is supported by NEFF and which is carried out in cooperation with the Institute for Energy Engineering of the ETHZ (Professor P. Suter). In addition to this, however, the author also head to find out about sill inexplained cases of corrosion in boilers which are being operated correctly, i.e. with comparably high boiler water and exhaust gas temperatures.

  10. 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)

  11. 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.

  12. Heat recovery from waste water by energy-saving heat pump systems in connection with water treatment plants

    Science.gov (United States)

    Wiedmann, U.; Flohrschuetz, R.

    1980-04-01

    The advantages of waste water recovery as an energy source were investigated. It was found that heat pump systems reach the highest performance coefficients and their primary energy ratios are competitive with conventional heating systems. It is concluded that the utilization of waste water treatment plants by large heat pump systems provides a considerable annual energy saving of light oil.

  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. EFFICIENCY AND LIFETIME OF SOLAR COLLECTORS FOR SOLAR HEATING PLANTS

    OpenAIRE

    Fan, Jianhua; Chen, Ziqian; Furbo, Simon; Perers, Bengt; Karlsson, Björn

    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 e...

  15. 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.

  16. 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.)

  17. 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...... as an unsustainable level of biomass consumption. Therefore, the regulatory framework should generally be considered in long-term planning of sustainable CHP systems....

  18. 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

  19. 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)

  20. Host plants of the tarnished plant bug (Heteroptera: Miridae) in Central Texas.

    Science.gov (United States)

    Esquivel, J F; Mowery, S V

    2007-08-01

    The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), has taken on added importance as a pest of cotton in the Cotton Belt after successful eradication efforts for the boll weevil (Anthonomus grandis grandis Boheman). Because the Southern Blacklands region of Central Texas is in advanced stages of boll weevil eradication, blooming weeds and selected row crops were sampled during a 3-yr study to determine lygus species composition and associated temporal host plants. L. lineolaris was the sole lygus species in the region. Thirteen previously unreported host plants were identified for L. lineolaris, of which 69% supported reproduction. Rapistrum rugosum L. Allioni and Ratibida columnifera (Nuttall) Wooton and Standley were primary weed hosts during the early season (17 March to 31 May). Conyza canadensis L. Cronquist variety canadensis and Ambrosia trifida L. were primary weed hosts during the midseason (1 June to 14 August) and late-season (15 August to 30 November), respectively. Sisymbrium irio L. and Lamium amplexicaule L. sustained L. lineolaris populations during the overwintering period (1 December to 16 March). The proportion of females and numbers of nymphs found in R. rugosum, C. canadensis, A. trifida, and S. irio suggests these weeds supported reproductive adults during the early, mid-, and late season and overwintering period, respectively. Medicago sativa L. was the leading crop host for L. lineolaris; Glycine max L. Merrill did not yield L. lineolaris. Few L. lineolaris were collected in Gossypium hirsutum L. These results provide a more comprehensive assessment of host plants contributing to L. lineolaris populations in central Texas.

  1. 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.

  2. Is sexual reproduction of high-mountain plants endangered by heat?

    Science.gov (United States)

    Ladinig, Ursula; Pramsohler, Manuel; Bauer, Ines; Zimmermann, Sonja; Neuner, Gilbert; Wagner, Johanna

    2015-04-01

    Strong solar irradiation in combination with still air and dry soil can cause prostrate high-mountain plants to heat up considerably and ultimately suffer heat damage. Such heat damage has been repeatedly shown for vegetative structures, but not for reproductive structures, which we expected to be particularly vulnerable to heat. Heat effects on cold-adapted plants may increase with rising global temperatures and the predicted increase in heat waves. We have tested the heat tolerance of reproductive versus vegetative shoots at different reproductive stages, comparing ten common plant species from different elevation belts in the European Alps. Plant samples were exposed to temperatures in 2-K steps of 30 min each between 42 and 56 °C. Heat damage was assessed by visual rating and vital staining. Reproductive shoots were on average 2.5 K less heat tolerant (LT50, i.e. the mean temperature causing 50 % heat damage, 47.2 °C) than vegetative shoots (mean LT50 49.7 °C). Initial heat injuries (mean LT10) were observed at 43-45 °C in heat-susceptible species and at 45-47 °C in more heat-tolerant species, in at least one reproductive stage. Generally, heat tolerance was significantly higher during fruiting than during the bud stages and anthesis. Prostrate species with acaulescent buds and flowers tolerated heat better than those with caulescent buds and flowers. Petals were the most heat-susceptible plant structure and mature pollen the most heat tolerant. Based on these data, heat tolerance of reproductive structures appears to be adapted to the prevailing maximum temperatures which the plants experience during different reproductive stages in their environment. During hot spells, however, heat tolerance thresholds may be exceeded. More frequent heat waves would decrease the reproductive output and, consequently, the competitiveness of heat-susceptible species.

  3. 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.

  4. Optimizing Waste Heat Recovery for Class A Biosolids Production from a Combined Cycle Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Soroushian, Fred

    2003-07-01

    The City of Corona serves a rapidly growing area of Southern California, The City operates three wastewater treatment plants (WWTPs) that produce reclaimed water for unrestricted reuse. The sludge from the three WWTPs is transported to a central sludge treatment facility located at WWTP No. 1. The sludge treatment facility consists of sludge receiving, thickening, anaerobic digestion, and dewatering. In the year 2000, the City was faced with two crises. First, the California power shortage and escalating cost of power severely impacted the industry and businesses. Second, bans on Class B biosolids land application and the shutdown of a local privatized composting facility where the bulk of the City's biosolids were processed or reused forced the City to transport bulk waste a much greater distance. To cost-effectively respond to these crises, the City decided to start generating and supplying power to its constituents by constructing a nominal 30-megawatt (MW) power plant. The feasibility study proved that locating the power plant at the City's largest WWTP produced significant synergies. The reclaimed water from the WWTP could be used for power plant cooling, the waste heat from the power plant could be recovered and used in Class A biosolids processes, the digester gas could be used for supplementing the fuel needs of the sludge dryer, and the combined facilities operation was more efficient than physically separate facilities. This paper presents the results of this analysis as well as the construction and operational aspects of the project. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    1976-05-25

    This preliminary design review package, consisting of the Software Performance Specification, Hardware Performance Specification, and the Verification Plan for the Central Data Processing System (CDPS), was prepared by the IBM Corporation. The Central Data Processing System, located at IBM's FSD facility in Huntsville, Alabama, provides the resources required to assess the performance of solar heating and cooling systems at remote sites. These sites include 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    1978-03-01

    This system design package for the Central Data Processing System consists of the Software Performance Specification, Hardware Performance Specification, Software Verification Plan, CDPS Development Program, Qualification and Acceptance Test Procedures, Qualification Test and Analysis Report, and Qualification and Acceptance Test Review. The Central Data Processing System, located at IBM's Federal System Division facility in Huntsville, Alabama, 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.

  7. 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)

  8. 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)

  9. 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...

  10. 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 ...

  11. Solar power tower design guide: Solar thermal central receiver power systems. A source of electricity and/or process heat

    Science.gov (United States)

    Battleson, K. W.

    1981-04-01

    Preliminary evaluations of whether a solar thermal central receiver plant is technically and economically feasible and desirable, for the potential user's application are reported. The cost elements, performance, and operation of solar central receiver systems are described.

  12. 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.

  13. 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.

  14. 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.)

  15. 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.

  16. Earthquake-proof plants; Centrales a prueba de terremotos

    Energy Technology Data Exchange (ETDEWEB)

    Francescutti, P.

    2008-07-01

    In the wake of the damage suffered by the Kashiwazaki-Kariwa nuclear power plant as a result of an earthquake last July, this article looks at the seismic risk affecting the Spanish plants and the safety measures in place to prevent it. (Author)

  17. Numerical study of local/regional atmospheric changes caused by a large solar central receiver power plant

    Science.gov (United States)

    Bhumralkar, C. M.; Slemmons, A. J.; Nitz, K. C.

    1981-06-01

    A two-dimensional numerical atmospheric mesoscale model with a vertical cross section is applied to study the potential local/regional atmospheric effects of the installation of a 100 MWe solar thermal central receiver power plant in California. The plant comprises heliostats (mirrors) covering a portion of ground surface and reflecting sunlight onto a central receiving tower. The model is able to simulate the changes in surface characteristics associated with the installation of heliostats and other power plant ancillaries and can also simulate the effects of waste heat from cooling towers. The model equations are integrated to simulate typical summer and atypical summer. The results for typical summer conditions at the site and in the surrounding region demonstrate that the power plant has the potential to increase local humidity and wind circulation but cannot induce the formation of clouds or rain. The results for atypical summer conditions show that the solar power plant is potentially able to increase the wind circulation and form clouds and rain. It is noted, however, that the life cycle of such formations is only 2-3 h.

  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. 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...

  20. 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...

  1. 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...

  2. 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.

  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. 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.

  5. Power generation plant integrating concentrated solar power receiver and pressurized heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Sakadjian, Bartev B; Flynn, Thomas J; Hu, Shengteng; Velazquez-Vargas, Luis G; Maryamchik, Mikhail

    2016-10-04

    A power plant includes a solar receiver heating solid particles, a standpipe receiving solid particles from the solar receiver, a pressurized heat exchanger heating working fluid by heat transfer through direct contact with heated solid particles flowing out of the bottom of the standpipe, and a flow path for solid particles from the bottom of the standpipe into the pressurized heat exchanger that is sealed by a pressure P produced at the bottom of the standpipe by a column of heated solid particles of height H. The flow path may include a silo or surge tank comprising a pressure vessel connected to the bottom of the standpipe, and a non-mechanical valve. The power plant may further include a turbine driven by heated working fluid discharged from the pressurized heat exchanger, and a compressor driven by the turbine.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. A new perspective on the 1930s mega-heat waves across central United States

    Science.gov (United States)

    Cowan, Tim; Hegerl, Gabi

    2016-04-01

    The unprecedented hot and dry conditions that plagued contiguous United States during the 1930s caused widespread devastation for many local communities and severely dented the emerging economy. The heat extremes experienced during the aptly named Dust Bowl decade were not isolated incidences, but part of a tendency towards warm summers over the central United States in the early 1930s, and peaked in the boreal summer 1936. Using high-quality daily maximum and minimum temperature observations from more than 880 Global Historical Climate Network stations across the United States and southern Canada, we assess the record breaking heat waves in the 1930s Dust Bowl decade. A comparison is made to more recent heat waves that have occurred during the latter half of the 20th century (i.e., in a warming world), both averaged over selected years and across decades. We further test the ability of coupled climate models to simulate mega-heat waves (i.e. most extreme events) across the United States in a pre-industrial climate without the impact of any long-term anthropogenic warming. Well-established heat wave metrics based on the temperature percentile threshold exceedances over three or more consecutive days are used to describe variations in the frequency, duration, amplitude and timing of the events. Casual factors such as drought severity/soil moisture deficits in the lead up to the heat waves (interannual), as well as the concurrent synoptic conditions (interdiurnal) and variability in Pacific and Atlantic sea surface temperatures (decadal) are also investigated. Results suggest that while each heat wave summer in the 1930s exhibited quite unique characteristics in terms of their timing, duration, amplitude, and regional clustering, a common factor in the Dust Bowl decade was the high number of consecutive dry seasons, as measured by drought indicators such as the Palmer Drought Severity and Standardised Precipitation indices, that preceded the mega-heat waves. This

  11. THE NITROGEN OXIDE CONCENTRATION DEPENDENCE ON HEAT LOSSES WITH EXIT SMOKE GASES OF HEAT-GENERATING PLANTS

    Directory of Open Access Journals (Sweden)

    A. A. Sedaev

    2012-04-01

    Full Text Available Problem statement. The most significant heat losses are losses associated with exit gases. It is these losses that determine the scale of heat emissions into the plant air with fuel combustion products and reduce the environmental safety of the plant. Many of the derived methods for reducing the nitrogen oxide emission associated with gas purification systems provide a high degree of smoke gas purification, but these methods are based on the use of various chemicals, which sharply reduces their environmental and operational characteristics.Results. The suggested method of simultaneous purification and recycling of gaseous emissions of heat-generating plants differs profitably from the existing ones. Its application will improve tech-nical and economic and also environmental characteristics of heat-generating plants and will make the characteristics of the energy enterprise a closer match to those of waste-free, environmentally-friendly and profitable enterprises.Conclusions. The obtained results confirm the fact that reduction of heat losses with exit gases re-sults in a reduction of nitrogen oxide emissions. Therefore, an increase in environmental safety of a boiler unit can be achieved in tandem with one in heat efficiency.

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

    Energy Technology Data Exchange (ETDEWEB)

    Palsson, H.

    2000-02-01

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

  13. 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

  14. 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.)

  15. 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

  16. 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

  17. Remote and Centralized Monitoring of PV Power Plants

    DEFF Research Database (Denmark)

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

    2014-01-01

    This paper presents the concept and operating principles of a low-cost and flexible monitoring system for PV plants. Compared to classical solutions which can require dedicated hardware and/or specialized data logging systems, the monitoring system we propose allows parallel monitoring of PV plan...... the diagnostic and condition monitoring capabilities of the PV system can be greatly enhanced. The practical implementation and operation of the monitoring system is demonstrated with a study case system deployed at Aalborg University.......This paper presents the concept and operating principles of a low-cost and flexible monitoring system for PV plants. Compared to classical solutions which can require dedicated hardware and/or specialized data logging systems, the monitoring system we propose allows parallel monitoring of PV plants...... with different architectures and locations by taking advantage of the intrinsic monitoring capabilities of the inverters and their internet connectivity. The backbone of the system is a software system capable of collecting production measurements and current-voltage (I-V) characteristic curve measurements from...

  18. 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...

  19. Calculation and Designing of Up-to-Date Gas-Flame Plants for Metal Heating and Heat Treatment

    Directory of Open Access Journals (Sweden)

    V. I. Тimoshpolsky

    2008-01-01

    Full Text Available An analysis of development trends in the CIS machine-building industry and current status of the heating and heat treatment furnaces of main machine-building enterprises of the Republic of Belarus as of the 1st quarter of 2008 is given in the paper.The paper presents the most efficient engineering solutions from technological and economic point of view that concern calculation and designing of up-to-date gas-flame plants which are to be applied for modernization of the current heating and heat treatment furnaces of the machine-building enterprises in the Republic of Belarus.A thermo-technical calculation of main indices of the up-to-date gas-flame plant has been carried out in the paper.

  20. 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)

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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%

  7. 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.

  8. Assessment of heat shock protein 70 induction by heat in alfalfa varieties and constitutive overexpression in transgenic plants.

    Directory of Open Access Journals (Sweden)

    Nicoletta Ferradini

    Full Text Available Heat shock proteins (HSPs are molecular chaperones involved in many cellular functions. It has been shown that mammalian cytosolic HSP70 binds antigenic peptides mediating the activation of the immune system, and that it plays a determining role in tumour immunogenicity. This suggests that HSP70 may be used for the production of conjugated vaccines. Human and plant HSPs share high sequence similarity and some important biological functions in vitro. In addition, plant HSPs have no endotoxic side effects. Extraction of HSP70 from plants for use as vaccine adjuvant requires enhancing its concentration in plant tissues. In this work, we explored the possibility to produce HSP70 in both transgenic and non-transgenic plants, using alfalfa as a model species. First, a transcriptional analysis of a constitutive and an inducible HSP70 genes was conducted in Arabidopsis thaliana. Then the coding sequence of the inducible form was cloned and introduced into alfalfa by Agrobacterium-mediated transformation, and the accumulation of the protein in leaf tissue of transgenic plants was demonstrated. We also tested diverse alfalfa varieties for heat-inducible expression of endogenous HSP70, revealing variety-specific responses to heat shock.

  9. 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.

  10. 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

  11. 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...

  12. 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

  13. Feedback quality and environmentally friendly use of domestic central heating systems.

    Science.gov (United States)

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

    2007-06-01

    The study examined the influence of system-embedded feedback on user behaviour during the environmentally friendly operation of a central heating system. A PC-based simulation, called CHESS, was developed to model the critical features of a central heating system. After having received 30 min of training on the simulation task, 60 participants worked on a series of operational scenarios under different levels of system feedback. In addition to the collection of various performance measures (e.g. energy consumption, energy wastage), a range of user variables was collected (e.g. environmental concern). As hypothesized, the results showed that increased feedback resulted in improved environmentally friendly performance and, more importantly, the specific feedback indicator influenced the type of strategy used to improve human - machine system performance. A major implication is that system designers need to develop feedback indicators that are chiefly influenced by user behaviour and are largely immune to factors that are beyond the user's control (e.g. weather conditions).

  14. Central Nervous System Effects of Ginkgo Biloba, a Plant Extract.

    Science.gov (United States)

    Itil, Turan M.; Eralp, Emin; Tsambis, Elias; Itil, Kurt Z.; Stein, Ulrich

    1996-01-01

    Extracts of Ginkgo biloba (EGb) are among the most prescribed drugs in France and Germany. EGb is claimed to be effective in peripheral arterial disorders and in "cerebral insufficiency." The mechanism of action is not yet well understood. Three of the ingredients of the extract have been isolated and found to be pharmacologically active, but which one alone or in combination is responsible for clinical effects is unknown. The recommended daily dose (3 x 40 mg extract) is based more on empirical data than on clinical dose-findings studies. However, despite these, according to double-blind, placebo-controlled clinical trials, EGb has therapeutic effects, at least, on the diagnostic entity of "cerebral insufficiency," which is used in Europe as synonymous with early dementia. To determine whether EGb has significant pharmacological effects on the human brain, a pharmacodynamic study was conducted using the Quantitative Pharmacoelectroencephalogram (QPEEG(R)) method. It was established that the pharmacological effects (based on a predetermined 7.5--13.0-Hz alpha frequency band in a computer-analyzed electroencephalogram = CEEG(R)) of EGb on the central nervous system (CNS) are significantly different than placebo, and the high and low doses could be discriminated from each other. The 120-mg, but particularly the 240-mg, single doses showed the most consistent CNS effects with an earlier onset (1 h) and longer duration (7 h). Furthermore, it was established that the electrophysiological effects of EGb in CNS are similar to those of well-known cognitive activators such as "nootropics" as well as tacrine, the only marketed "antidementia" drug currently available in the United States. PMID:11856998

  15. Central Nervous System Effects of Ginkgo Biloba, a Plant Extract.

    Science.gov (United States)

    Itil, Turan M.; Eralp, Emin; Tsambis, Elias; Itil, Kurt Z.; Stein, Ulrich

    1996-01-01

    Extracts of Ginkgo biloba (EGb) are among the most prescribed drugs in France and Germany. EGb is claimed to be effective in peripheral arterial disorders and in "cerebral insufficiency." The mechanism of action is not yet well understood. Three of the ingredients of the extract have been isolated and found to be pharmacologically active, but which one alone or in combination is responsible for clinical effects is unknown. The recommended daily dose (3 x 40 mg extract) is based more on empirical data than on clinical dose-findings studies. However, despite these, according to double-blind, placebo-controlled clinical trials, EGb has therapeutic effects, at least, on the diagnostic entity of "cerebral insufficiency," which is used in Europe as synonymous with early dementia. To determine whether EGb has significant pharmacological effects on the human brain, a pharmacodynamic study was conducted using the Quantitative Pharmacoelectroencephalogram (QPEEG(R)) method. It was established that the pharmacological effects (based on a predetermined 7.5--13.0-Hz alpha frequency band in a computer-analyzed electroencephalogram = CEEG(R)) of EGb on the central nervous system (CNS) are significantly different than placebo, and the high and low doses could be discriminated from each other. The 120-mg, but particularly the 240-mg, single doses showed the most consistent CNS effects with an earlier onset (1 h) and longer duration (7 h). Furthermore, it was established that the electrophysiological effects of EGb in CNS are similar to those of well-known cognitive activators such as "nootropics" as well as tacrine, the only marketed "antidementia" drug currently available in the United States.

  16. 15 Years of R&D in Central Solar Heating in Denmark

    DEFF Research Database (Denmark)

    Heller, Alfred

    2000-01-01

    , pit water storage is presented and conclusions are drawn. R&D in the field of CSHPs call for international co-operation, knowledge transfer and not least financing. The structural and political climate that shapes the boundaries of the R&D activities and also makes up the dominant barrier...... and the application of variable flow that lead to novelties in the control strategy. The plant is described and experiences are analysed. The presented cases show that the technology, under special conditions, can be economically competitive with other heating technologies. Under normal conditions, public funding...

  17. 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.

  18. 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.

  19. Role and regulation of autophagy in heat stress responses of tomato plants.

    Science.gov (United States)

    Zhou, Jie; Wang, Jian; Yu, Jing-Quan; Chen, Zhixiang

    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 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 (VIGS) 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.

  20. 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.

  1. Codigestion of manure and organic wastes in centralized biogas plants: status and future trends.

    Science.gov (United States)

    Angelidaki, I; Ellegaard, L

    2003-01-01

    Centralized biogas plants in Denmark codigest mainly manure, together with other organic waste such as industrial organic waste, source sorted household waste, and sewage sludge. Today 22 large-scale centralized biogas plants are in operation in Denmark, and in 2001 they treated approx 1.2 million tons of manure as well as approx 300,000 of organic industrial waste. Besides the centralized biogas plants there are a large number of smaller farm-scale plants. The long-term energy plan objective is a 10-fold increase of the 1998 level of biogas production by the year 2020. This will help to achieve a target of 12-14% of the national energy consumption being provided by renewable energy by the year 2005 and 33% by the year 2030. A major part of this increase is expected to come from new centralized biogas plants. The annual potential for biogas production from biomass resources available in Denmark is estimated to be approx 30 Peta Joule (PJ). Manure comprises about 80% of this potential. Special emphasis has been paid to establishing good sanitation and pathogen reduction of the digested material, to avoid risk of spreading pathogens when applying the digested manure as fertilizer to agricultural soils.

  2. Application and design of an economizer for waste heat recovery in a cogeneration plant

    Directory of Open Access Journals (Sweden)

    Martić Igor I.

    2016-01-01

    Full Text Available Energy increase cost has required its more effective use. However, many industrial heating processes generate waste energy. Use of waste-heat recovery systems decreases energy consumption. This paper presents case study of waste heat recovering of the exhaust flue gas in a 1415 kWe cogeneration plant. This waste heat can be recovered by installing an economizer to heat the condensed and fresh water in thermal degasification unit and reduce steam use for maintaining the temperature of 105˚C for oxygen removal. Design methodology of economizer is presented.

  3. 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)

  4. 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.

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

    Science.gov (United States)

    Fsadni, A.-M.; Ge, Y. T.

    2013-04-01

    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.

  6. First experience gained with heat-pump utilization in animal-husbandry plants

    Energy Technology Data Exchange (ETDEWEB)

    Kuemmritz, W.; Schaeffel, W.

    1982-10-01

    For cleaning and desinfection of all milk-conducting plant parts, the LPG Tierproduktion at the town of Berlstedt (capacity of 2000 animal stands) needs a daily amount of c. 60 cbm of heated water. Recently 50% of this useful-water requirement has been covered by four small-size heat pumps WW 12 of a water/water configuration. In the heating house, two heat pumps have been installed on top of each other in each case. The circuit plan of the heat-pump facility is demonstrated. The facility operates at open and closed loop, contains two-step rotary pumps and heats useful water to 50-60/sup 0/C. Two heat pumps are operated via shift water throughout the year, the remaining two use brook water in summer and well water in winter as their heat source. 40 t of fuel oil were saved in 1981.

  7. The Plant Heat Stress Transcription Factors (HSFs): Structure, Regulation, and Function in Response to Abiotic Stresses.

    Science.gov (United States)

    Guo, Meng; Liu, Jin-Hong; Ma, Xiao; Luo, De-Xu; Gong, Zhen-Hui; Lu, Ming-Hui

    2016-01-01

    Abiotic stresses such as high temperature, salinity, and drought adversely affect the survival, growth, and reproduction of plants. Plants respond to such unfavorable changes through developmental, physiological, and biochemical ways, and these responses require expression of stress-responsive genes, which are regulated by a network of transcription factors (TFs), including heat stress transcription factors (HSFs). HSFs play a crucial role in plants response to several abiotic stresses by regulating the expression of stress-responsive genes, such as heat shock proteins (Hsps). In this review, we describe the conserved structure of plant HSFs, the identification of HSF gene families from various plant species, their expression profiling under abiotic stress conditions, regulation at different levels and function in abiotic stresses. Despite plant HSFs share highly conserved structure, their remarkable diversification across plants reflects their numerous functions as well as their integration into the complex stress signaling and response networks, which can be employed in crop improvement strategies via biotechnological intervention.

  8. The plant heat stress transcription factors (HSFs: structure, regulation and function in response to abiotic stresses

    Directory of Open Access Journals (Sweden)

    Meng eGuo

    2016-02-01

    Full Text Available Abiotic stresses such as high temperature, salinity and drought adversely affect the survival, growth and reproduction of plants. Plants respond to such unfavorable changes through developmental, physiological and biochemical ways, and these responses require expression of stress-responsive genes, which are regulated by a network of transcription factors (TFs, including heat stress transcription factors (HSFs. HSFs play a crucial role in plants response to several abiotic stresses by regulating the expression of stress-responsive genes, such as heat shock proteins (Hsps. In this review, we describe the conserved structure of plant HSFs, the identification of HSF gene families from various plant species, their expression profiling under abiotic stress conditions, regulation at different levels and function in abiotic stresses. Despite plant HSFs share highly conserved structure, their remarkable diversification across plants reflects their numerous functions as well as their integration into the complex stress signaling and response networks, which can be employed in crop improvement strategies via biotechnological intervention.

  9. 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...

  10. 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...

  11. 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

  12. 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.

  13. 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%.

  14. 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.

  15. 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)

  16. 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.

  17. 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.

  18. Anomalous subglacial heat flow in central Greenland induced by the Iceland plume.

    Science.gov (United States)

    Petrunin, Alexey G.; Rogozhina, Irina; Kaban, Mikhail K.; Vaughan, Alan P. M.; Steinberger, Bernhard; Johnson, Jesse; Koulakov, Ivan; Thomas, Maik

    2013-04-01

    3000 m of ice sheet thickness has ensured that central Greenland has kept it geothermal heat flow (GHF) distribution enigmatic. Some few direct ice temperature measurements from deep ice cores reveal a GHF of 50 to 60 mW/m² in the Summit region and this is noticeably above what would be expected for the underlying Early Proterozoic lithosphere. In addition, indirect estimates from zones of rapid basal melting suggest extreme anomalies 15 to 30 times continental background. Subglacial topography indicates caldera like topographic features in the zones hinting at possible volcanic activity in the past [1], and all of these observations combined hint at an anomalous lithospheric structure. Further supporting this comes from new high-resolution P-wave tomography, which shows a strong thermal anomaly in the lithosphere crossing Greenland from east to west [2]. Rock outcrops at the eastern and western end of this zone indicate significant former magmatic activity, older in the east and younger in the west. Additionally, plate modelling studies suggest that the Greenland plate passed over the mantle plume that is currently under Iceland from late Cretaceous to Neogene times, consistent with the evidence from age of magmatism. Evidence of rapid basal melt revealed by ice penetrating radar along the hypocentre of the putative plume track indicates that it continues to affect the Greenland continental geotherm today. We analyse plume-induced thermal disturbance of the present-day lithosphere and their effects on the central Greenland ice sheet by using a novel evolutionary model of the climate-ice-lithosphere-upper mantle system. Our results indicate that mantle plume-induced erosion of the lithosphere has occurred, explaining caldera-type volcanic structures, the GHF anomaly, and requiring dyke intrusion into the crust during the early Cenozoic. The residual thermo-mechanical effect of the mantle plume has raised deep-sourced heat flow by over 25 mW/m² since 60 Ma and

  19. 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).

  20. Effects of Autumn and Spring Heat Waves on Seed Germination of High Mountain Plants.

    Science.gov (United States)

    Orsenigo, Simone; Abeli, Thomas; Rossi, Graziano; Bonasoni, Paolo; Pasquaretta, Cristian; Gandini, Maurizia; Mondoni, Andrea

    2015-01-01

    Alpine plants are considered to be particularly vulnerable to climate change and related extreme episodes, such as heat waves. Despite growing interest in the impact of heat waves on alpine plants, knowledge about their effects on regeneration is still fragmentary. Recruitment from seeds will be crucial for the successful migration and survival of these species and will play a key role in their future adaptation to climate change. In this study, we assessed the impacts of heat waves on the seed germination of 53 high mountain plants from the Northern Apennines (Italy). The seeds were exposed to laboratory simulations of three seasonal temperature treatments, derived from real data recorded at a meteorological station near the species growing site, which included two heat wave episodes that occurred both in spring 2003 and in autumn 2011. Moreover, to consider the effect of increasing drought conditions related to heat waves, seed germination was also investigated under four different water potentials. In the absence of heat waves, seed germination mainly occurred in spring, after seeds had experienced autumn and winter seasons. However, heat waves resulted in a significant increase of spring germination in c. 30% of the species and elicited autumn germination in 50%. When heat waves were coupled with drought, seed germination decreased in all species, but did not stop completely. Our results suggest that in the future, heat waves will affect the germination phenology of alpine plants, especially conditionally dormant and strictly cold-adapted chorotypes, by shifting the emergence time from spring to autumn and by increasing the proportion of emerged seedlings. The detrimental effects of heat waves on recruitment success is less likely to be due to the inhibition of seed germination per se, but rather due to seedling survival in seasons, and temperature and water conditions that they are not used to experiencing. Changes in the proportion and timing of emergence

  1. 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.

  2. 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.)

  3. 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. ...

  4. 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

  5. Solar heating and hot water system for the central administrative office facility. Technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    1978-11-01

    Progress on the solar heating and hot water system for the central administrative office facility of the Lincoln Housing Authority, Lincoln, NE is covered. An acceptance test plan is presented and the results of the test are tabulated. A complete blueprint of the system as built is provided. The monitoring system is drawn and settings and installation are described. An operation and maintenance manual discusses procedures for start up, shut down and seasonal changeover and include a valve list and pictures and specifications of components and materials used. Photographs of the final installation are included, and technical data and performance data are given. Finally, there is a brief description of system design and operation and a discussion of major maintenance problems encountered and their solutions. (LEW)

  6. 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.

  7. 10 CFR Appendix M to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Central Air Conditioners and Heat Pumps

    Science.gov (United States)

    2010-01-01

    ... of Central Air Conditioners and Heat Pumps M Appendix M to Subpart B of Part 430 Energy DEPARTMENT OF... Consumption of Central Air Conditioners and Heat Pumps 1. DEFINITIONS 2. TESTING CONDITIONS 2.1Test room... conditioners and heat pumps, and systems composed of multiple mini-split units (outdoor units located...

  8. Control engineering and central supervision for ammonia refrigeration plants; Regelungstechnik und zentrale Leittechnik fuer Ammoniakkaelteanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Wendelborn, H. [Danfoss Waerme- und Kaeltetechnik GmbH, Heusenstamm (Germany)

    1996-04-01

    A brief overall view for mechanical and electronic liquid level controllers for flooded evaporators and NH{sub 3} surge drums, evaporator controllers, compound plant controllers and central supervision technology for industrial refrigeration plants will be presented. Using a fresh produce distribution centre with an ammonia refrigeration plant and surge drums as an example the controls operation and the central supervision technology will be described. (orig.) [Deutsch] Es wird eine Uebersicht ueber die mechanische und elektronische Niveauregelung von ueberfluteten Verdampfern und NH{sub 3}-Abscheidern, ueber Kuehlstellenregler, Verbundanlagenregler und ueber zentrale Leittechnik fuer Industriekaelteanlagen gegeben. Anhand eines Frischware-Verteilzentrums, dessen Kaelteanlage mit drei NH{sub 3}-Abscheidern ausgeruestet ist, wird beispielhaft der Regelbetrieb des elektronischen Niveaureglers und der Leittechnik beschrieben. (orig.)

  9. 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)

  10. 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

  11. 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.

  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. 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)

  14. 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

  15. 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

    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......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...

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

    Science.gov (United States)

    Upathumchard, Ularee

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

  17. Application of microwave heating to a polyesterification plant

    NARCIS (Netherlands)

    Komorowska-Durka, M.

    2015-01-01

    Utilizing microwave irradiation, a fundamentally different method of the energy transfer, to the chemical process units can potentially be advantageous compared to the conventional heating, inter alia due to the selective nature of interaction of the microwaves with the matter. This doctoral dissert

  18. 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

  19. 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)

  20. 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.

  1. Heat integration of an Olefins Plant: Pinch Analysis and mathematical optimization working together

    Directory of Open Access Journals (Sweden)

    M. Beninca

    2011-03-01

    Full Text Available This work explores a two-step, complexity reducing methodology, to analyze heat integration opportunities of an existing Olefins Plant, identify and quantify reduction of energy consumption, and propose changes of the existing heat exchanger network to achieve these goals. Besides the analysis of plant design conditions, multiple operational scenarios were considered to propose modifications for handling real plant operation (flexibility. On the strength of plant complexity and large dimension, work methodology was split into two parts: initially, the whole plant was evaluated with traditional Pinch Analysis tools. Several opportunities were identified and modifications proposed. Modifications were segregated to represent small and independent portions of the original process. One of them was selected to be re-analyzed, considering two scenarios. Reduction of problem dimension allowed mathematical methodologies (formulation with decomposition, applying LP, MILP and NLP optimization methods to synthesize flexible networks to be applied, generating a feasible modification capable of fulfilling the proposed operational scenarios.

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

    Science.gov (United States)

    Lhotka, Ondrej; Plavcová, Eva; Kyselý, Jan

    2016-04-01

    The 2015 summer was the warmest summer ever observed in Central Europe according to many characteristics, including the overall severity of heat waves. We assess how unusual this summer was by i) comparing the seasonal temperature anomalies and severity of heat waves against long-term temperature records at Central European stations, ii) evaluating its temperature characteristics at the continental scale against hot summers and major heat waves affecting Europe recently (including the 2003 western-European heat waves and the 2010 Russian heat waves), and iii) identifying time slices in climate change scenarios for the 21st century in which similar events are projected to occur over Central Europe at least once per decade. In the last point, we make use of a large ensemble of RCM simulations from CORDEX and ENSEMBLES projects and critically evaluate their ability to simulate events such as the 2015 summer (in terms of both seasonal temperature anomalies and heat waves, including their spatial extent). We examine also how results for the climate change scenarios depend on radiative forcing and driving global models.

  3. 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…

  4. 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.

  5. Perapion connexum (Schilsky, 1902 (Coleoptera, Apionidae in Central Europe, a case of plant expansion chase

    Directory of Open Access Journals (Sweden)

    Marek Wanat

    2012-03-01

    Full Text Available Perapion connexum (Schilsky is recorded for the first time from Hungary and Kyrgyzstan, and new distribution data from Ukraine and Russia are provided. Preliminary placements of this weevil in faunal checklists for Poland and Slovakia are here documented with detailed data. Its occurrence in Austria based on older evidence, is discussed. The neophytic and invasive in Central Europe sorrel Rumex confertus Willd. is confirmed to be its unique host plant in Poland. Morphology of the newcoming weevil is described and illustrated, and the key to all Central European species of Perapion is presented.

  6. 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.

  7. From gene manipulation to forest establishment: shoot cultures of woody plants can be a central tool

    Energy Technology Data Exchange (ETDEWEB)

    McCown, B.H.

    1985-05-01

    Establishing germplasm of woody plants in microculture as shoot cultures has proved to be an effective method of overcoming many of the obstacles in working with these crops. Shoot cultures eliminate the changes associated with seasonal growth cycles and phase change and put large plants into a more manageable form. Well-established shoot cultures are central to successful clonal propagation systems for forest trees as well as to genetic improvement based on the use of cellular techniques such as protoplast manipulation. The physiological basis as to why tissues from shoot cultures are so readily manipulated is not well understood.

  8. 吸收式热泵用于热电联产改造新技术%The Co-production of New Technology Transformation of Usage of Absorption Hot-pump to Recycle Waste Heat in Heat Power Plant

    Institute of Scientific and Technical Information of China (English)

    茹毅; 王飞

    2012-01-01

    热电厂的循环冷却水系统存在大量的低位热能。热泵系统具有将低位热能提升为高位热能的能力。本文即是根据山西某热电厂的节能改造方案介绍了利用吸收式热泵系统回收电厂冷凝余热用于集中供热的新技术;并对新型供热系统做出能效和经济性评价,认为新技术应用具有经济和环境的双重效益,有广阔发展前景。%There is a large number of low level heat energy in the circulating cooling water system of thermal power plant.Heat pump system has the ability to improve the heat energy level from low order into high order.This article introduced the new technology,application to central heating,of usage of absorption high temperature heat pump system for recycling waste heat of condensation which based on the energy-saving reform plan of one heat-power plant in Shanxi province.Based on the new central heating systems the energy efficiency and economic evaluation be giving in this paper.Through the analysis shows that the application of new technology has the double effect in economic efficiency and environmental protection that has broad prospects for development.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. Land surface and atmospheric conditions associated with heat waves over the Chickasaw Nation in the South Central United States

    Science.gov (United States)

    Lee, Eungul; Bieda, Rahama; Shanmugasundaram, Jothiganesh; Basara Richter, Heather

    2016-06-01

    Exposure to extreme heat was reconstructed based on regional land-atmosphere processes from 1979 to 2010 in the South Central U.S. The study region surrounds the Chickasaw Nation (CN), a predominantly Native American population with a highly prevalent burden of climate-sensitive chronic diseases. Land surface and atmospheric conditions for summer heat waves were analyzed during spring (March-April-May, MAM) and summer (June-July-August, JJA) based on the Climate and Ocean: Variability, Predictability, and Change maximum temperature definition for heat wave frequency (HWF). The spatial-temporal pattern of HWF was determined using empirical orthogonal function (EOF) analysis and the corresponding principle component time series of the first EOF of HWF. Statistically significant analyses of observed conditions indicated that sensible heat increased and latent heat fluxes decreased with high HWF in the South Central U.S. The largest positive correlations of sensible heat flux to HWF and the largest negative correlations of latent heat flux to HWF were specifically observed over the CN. This is a significantly different energy transfer regime due to less available soil moisture during the antecedent MAM and JJA. The higher sensible heat from dry soil could cause significant warming from the near surface (>2.0°C) to the lower troposphere (>1.5°C), and accumulated boundary layer heat could induce the significant patterns of higher geopotential height and enhance anticyclonic circulations (negative vorticity anomaly) at the midtroposphere. Results suggested a positive land-atmosphere feedback associated with heat waves and called attention to the need for region-specific climate adaptation planning.

  14. 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)

  15. 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.

  16. 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...

  17. 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.)

  18. 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.

  19. 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...

  20. 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.

  1. 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

  2. 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

  3. 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.

  4. 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.)

  5. 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.

  6. 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

  7. Micro bubble formation and bubble dissolution in domestic wet central heating systems

    Directory of Open Access Journals (Sweden)

    Ge Yunting

    2012-04-01

    Full Text Available 16 % of the carbon dioxide emissions in the UK are known to originate from wet domestic central heating systems. Contemporary systems make use of very efficient boilers known as condensing boilers that could result in efficiencies in the 90-100% range. However, research and development into the phenomenon of micro bubbles in such systems has been practically non-existent. In fact, such systems normally incorporate a passive deaerator that is installed as a ‘default’ feature with no real knowledge as to the micro bubble characteristics and their effect on such systems. High saturation ratios are known to occur due to the widespread use of untreated tap water in such systems and due to the inevitable leakage of air into the closed loop circulation system during the daily thermal cycling. The high temperatures at the boiler wall result in super saturation conditions which consequently lead to micro bubble nucleation and detachment, leading to bubbly two phase flow. Experiments have been done on a test rig incorporating a typical 19 kW domestic gas fired boiler to determine the expected saturation ratios and bubble production and dissolution rates in such systems.

  8. Micro bubble formation and bubble dissolution in domestic wet central heating systems

    Science.gov (United States)

    Fsadni, Andrew M.; Ge, Yunting

    2012-04-01

    16 % of the carbon dioxide emissions in the UK are known to originate from wet domestic central heating systems. Contemporary systems make use of very efficient boilers known as condensing boilers that could result in efficiencies in the 90-100% range. However, research and development into the phenomenon of micro bubbles in such systems has been practically non-existent. In fact, such systems normally incorporate a passive deaerator that is installed as a `default' feature with no real knowledge as to the micro bubble characteristics and their effect on such systems. High saturation ratios are known to occur due to the widespread use of untreated tap water in such systems and due to the inevitable leakage of air into the closed loop circulation system during the daily thermal cycling. The high temperatures at the boiler wall result in super saturation conditions which consequently lead to micro bubble nucleation and detachment, leading to bubbly two phase flow. Experiments have been done on a test rig incorporating a typical 19 kW domestic gas fired boiler to determine the expected saturation ratios and bubble production and dissolution rates in such systems.

  9. 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

  10. 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.

  11. 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)

  12. 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

  13. 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.

  14. The automatic operation of the Rance plant; La conduite automatique de la centrale de la Rance

    Energy Technology Data Exchange (ETDEWEB)

    Charon, A. [EDF, 75 - Paris (France)

    1997-12-31

    The programming of the functioning cycles of the Rance plant takes into account the tide cycle, the estimated availability of turbine-groups and sluice gates, the weekly estimations and the external constraints. In the beginning, the AGRA computer code was used to propose a detailed program for plant operation which was carried out by the shift operating personnel. The programme schedule system became obsolete in the beginning of the 80`s and choice was given to a completely automatized operating system with suppression of the shift operating service. Programming was still based on AGRA but the code was modified to take into account a better modeling of the Rance estuary. Because of the huge size of the plant (390 m of length), a decentralized structure was retained (turbine-groups were connected together by sets of four units). The common treatments are centralized by a single computer. (J.S.)

  15. 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.

  16. 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

  17. Thermal analysis of heat and power plant with high temperature reactor and intermediate steam cycle

    Science.gov (United States)

    Fic, Adam; Składzień, Jan; Gabriel, Michał

    2015-03-01

    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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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...

  5. Impact of Stationary Direct Current in the Central Solenoidal Coil on Tokamak Plasma Formation by Non-induction Heating

    Science.gov (United States)

    Watanabe, Osamu

    2016-09-01

    Stationary direct current in the central solenoidal coil (DCCS) of tokamak devices can reduce the non-induction heating energy necessary for tokamak plasma formation. The magnetic field energy in the inner region of the central solenoidal coil (CS region) is expelled during the tokamak plasma formation, because the vertical magnetic field intensity generated by the central solenoidal coil and poloidal field coils is partly cancelled by the increase in the toroidal plasma current. Because this magnetic field energy expelled from the CS region is distributed to the tokamak plasma in accordance with the mutual inductance, this expelled energy can drive the toroidal plasma current inductively. This energy expulsion in the CS region can be enhanced by the DCCS without the modification of the tokamak plasma configuration, when the CS coil current has negligible leakage magnetic field in the plasma area. Because the drive of the toroidal plasma current by non-induction heating can be assisted by this inductive current drive mechanism, the non-induction heating energy necessary for the tokamak plasma formation can be reduced by the DCCS. If the non-induction heating is constant, the tokamak plasma formation time can be shorted by the DCCS.

  6. 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.

  7. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Taveau, F.; Huiban, A.M. [Alstom Power Heat Exchange, 78 - Velizy Villacoublay (France)

    2001-07-01

    With the current evolutions of the energy market and the life extension of the power plants, all the equipment initially supplied need one day or another partial or total rehabilitation. For heat exchange equipment, this includes the condensers, feed water heaters and various heat exchangers. Modernization is in particular necessary when in-service monitoring and periodic inspections show significant deteriorations of the tubes and cooling water leakages leading to forced outages or when tube and tube plate materials are no longer suited to cooling water characteristics or to updated specifications of the secondary system. Feedwater heaters and heat exchangers damaged by erosion/corrosion, vibrations, etc. can be re-designed, manufactured and replaced easily. The operation is more complex on condensers and requires technical surveys, study of alternative solutions and has a more direct impact on the global output of the power plant. That is why our conference will focus on the condenser refurbishment. (author)

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. Distribution pattern and conservation of threatened medicinal and aromatic plants of Central Himalaya, India

    Institute of Scientific and Technical Information of China (English)

    L. S. Kandari; K.S. Rao; R. K. Maikhuri; G. Kharkwal; K. Chauhan; C.P. Kala

    2011-01-01

    A study was conducted to examine the distribution pattern of four rhizomatous medicinal and aromatic plant species (MAPs) viz., Angelica glauca, Pleurospermum angelicoides, Rheum emodi and Arne- bia benthamii in different forest stands in Central Himalaya. Results show that A. Glauca and P. Angelicoides had a higher (50%) frequency at Chipkoan, Garpak and Phagati forest, R. Emodi had a higher (60%) fre- quency at Rishikund, Suki and Himtoli, and A. Benthamii had a higher (70%) frequency at Suki and Khambdhar The densities of A. Glauca (0.6 plants·m) and P. Angelicoides (0.5 plants·m) were higher at Chipkoan and Garpak sites than at other micro-sites, while densities of R. Emodi (0.8 plants·m) and A. Benthamii (1.0 plants·m) were higher at Suki and Khambdhar sites. A. Glauca had highest total basal covers (TBC) (1.2 cm·m) at Chipkoan, P. Angelicoides had highest TBC (0.92 cm·m) at Lati kharak site, A. Benthamii had the highest TBC (6.48 cm·m) at Khambdhar, and R. Emodi had highest TBC (4.53 cm·m) at Rishikund. For the four studied species, A. Glauca showed a contagious distribution, P. Angelicoides and R. Emodi showed the random and A. Benthamii showed the regular type of distribution.

  14. A Central Role for Thiols in Plant Tolerance to Abiotic Stress

    Directory of Open Access Journals (Sweden)

    Lyuben Zagorchev

    2013-04-01

    Full Text Available Abiotic stress poses major problems to agriculture and increasing efforts are being made to understand plant stress response and tolerance mechanisms and to develop new tools that underpin successful agriculture. However, the molecular mechanisms of plant stress tolerance are not fully understood, and the data available is incomplete and sometimes contradictory. Here, we review the significance of protein and non-protein thiol compounds in relation to plant tolerance of abiotic stress. First, the roles of the amino acids cysteine and methionine, are discussed, followed by an extensive discussion of the low-molecular-weight tripeptide, thiol glutathione, which plays a central part in plant stress response and oxidative signalling and of glutathione-related enzymes, including those involved in the biosynthesis of non-protein thiol compounds. Special attention is given to the glutathione redox state, to phytochelatins and to the role of glutathione in the regulation of the cell cycle. The protein thiol section focuses on glutaredoxins and thioredoxins, proteins with oxidoreductase activity, which are involved in protein glutathionylation. The review concludes with a brief overview of and future perspectives for the involvement of plant thiols in abiotic stress tolerance.

  15. 75 FR 14368 - Energy Conservation Standards for Residential Central Air Conditioners and Heat Pumps: Public...

    Science.gov (United States)

    2010-03-25

    ... conditioners and heat pumps. 66 FR 7170. The amended standards would have increased the minimum SEER to 13 for... and heat pumps; the analytical framework, models, and tools that DOE is using to evaluate amended... Heat Pumps, EERE-2008-BT- STD-0006, 1000 Independence Avenue, SW., Washington, DC 20585-0121....

  16. Perspectives on deciphering mechanisms underlying plant heat stress response and thermotolerance

    Directory of Open Access Journals (Sweden)

    Kamila Lucia Bokszczanin

    2013-08-01

    Full Text Available Global warming is a major threat for agriculture and food safety and in many cases the negative effects are already apparent. The current challenge of basic and applied plant science is to decipher the molecular mechanisms of heat stress response and thermotolerance in detail and use this information to identify genotypes that will withstand unfavorable environmental conditions. Nowadays X-omics approaches complement the findings of previous targeted studies and highlight the complexity of heat stress response mechanisms giving information for so far unrecognized genes, proteins and metabolites as potential key players of thermotolerance. Even more, roles of epigenetic mechanisms and the involvement of small RNAs in thermotolerance are currently emerging and thus open new directions of yet unexplored areas of plant heat stress response. In parallel it is emerging that although the whole plant is vulnerable to heat, specific organs are particularly sensitive to elevated temperatures. This has redirected research from the vegetative to generative tissues. The sexual reproduction phase is considered as the most sensitive to heat and specifically pollen exhibits the highest sensitivity and frequently an elevation of the temperature just a few degrees above the optimum during pollen development can have detrimental effects for crop production. Compared to our knowledge on heat stress response of vegetative tissues, the information on pollen is still scarce. Nowadays, several techniques for high-throughput X-omics approaches provide major tools to explore the principles of pollen heat stress response and thermotolerance mechanisms in specific genotypes. The collection of such information will provide an excellent support for improvement of breeding programs to facilitate the development of tolerant cultivars. The review aims at describing the current knowledge of thermotolerance mechanisms and the technical advances which will foster new insights into

  17. 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.

  18. 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.

  19. District heating and cooling system for communities through power plant retrofit and distribution network. Final report, Phase I

    Energy Technology Data Exchange (ETDEWEB)

    1979-06-01

    The technical and economic feasibility of retrofitting thermal power plants in Minnesota to accommodate both heat and power generation for district heating was examined and is discussed. Three communities were identified as viable sites for co-generation district heating. (LCL)

  20. 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.

  1. 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.

  2. 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)

  3. 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).

  4. 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).

  5. 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)

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. Elevating optimal human nutrition to a central goal of plant breeding and production of plant-based foods.

    Science.gov (United States)

    Sands, David C; Morris, Cindy E; Dratz, Edward A; Pilgeram, Alice

    2009-11-01

    High-yielding cereals and other staples have produced adequate calories to ward off starvation for much of the world over several decades. However, deficiencies in certain amino acids, minerals, vitamins and fatty acids in staple crops, and animal diets derived from them, have aggravated the problem of malnutrition and the increasing incidence of certain chronic diseases in nominally well-nourished people (the so-called diseases of civilization). Enhanced global nutrition has great potential to reduce acute and chronic disease, the need for health care, the cost of health care, and to increase educational attainment, economic productivity and the quality of life. However, nutrition is currently not an important driver of most plant breeding efforts, and there are only a few well-known efforts to breed crops that are adapted to the needs of optimal human nutrition. Technological tools are available to greatly enhance the nutritional value of our staple crops. However, enhanced nutrition in major crops might only be achieved if nutritional traits are introduced in tandem with important agronomic yield drivers, such as resistance to emerging pests or diseases, to drought and salinity, to herbicides, parasitic plants, frost or heat. In this way we might circumvent a natural tendency for high yield and low production cost to effectively select against the best human nutrition. Here we discuss the need and means for agriculture, food processing, food transport, sociology, nutrition and medicine to be integrated into new approaches to food production with optimal human nutrition as a principle goal.

  11. 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.

  12. 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

    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...

  13. 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

    /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...

  14. 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)

  15. 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)

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. New gasification plants for combined heat and power in Denmark; Nye forgasningsanlaeg til kraftvarme i Danmark

    Energy Technology Data Exchange (ETDEWEB)

    Houmoeller, S.

    1997-12-31

    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

  1. Carbon emission impact on the operation of virtual power plant with combined heat and power system

    Institute of Scientific and Technical Information of China (English)

    Yu-hang XIA; Jun-yong LIU; Zheng-wen HUANG; Xu ZHANG

    2016-01-01

    A virtual power plant (VPP) can realize the aggregation of distributed generation in a certain region, and represent distributed generation to participate in the power market of the main grid. With the expansion of VPPs and ever-growing heat demand of consumers, managing the effect of fluctuations in the amount of available renewable resources on the operation of VPPs and maintaining an economical supply of electric power and heat energy to users have been important issues. This paper proposes the allocation of an electric boiler to realize wind power directly converted for supplying heat, which can not only overcome the limitation of heat output from a combined heat and power (CHP) unit, but also reduce carbon emissions from a VPP. After the electric boiler is considered in the VPP operation model of the combined heat and power system, a multi-objective model is built, which includes the costs of carbon emissions, total operation of the VPP and the electricity traded between the VPP and the main grid. The model is solved by the CPLEX package using the fuzzy membership function in Matlab, and a case study is pre-sented. The power output of each unit in the case study is analyzed under four scenarios. The results show that after carbon emission is taken into account, the output of low carbon units is significantly increased, and the allocation of an electric boiler can facilitate the maximum absorption of renewable energy, which also reduces carbon emissions from the VPP.

  2. Combustion testing and heat recovery study: Frank E. Van Lare Wastewater Treatment Plant, Monroe County. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Chattopadhyay, A.

    1995-01-01

    The report describes the results of combustion testing work, and analysis of heat recovery and use at the Monroe County Frank E. Van Lare wastwater treatment plant (WWTP). The three multiple-hearth furnaces at the plant process an average of 65 dry tons of dewatered sludge per day. The furnaces use about 12.5 million Btus of natural gas per dry ton of sludge incinerated, or about 300 billion Btus per year. Center shaft and rabble arm cooling air is recirculated to the furnaces as pre-heated combustion air. No other heat from the combustion process is recovered for use in the plant. The project had four objectives: to record and analyze sludge management operations data and sludge incinerator combustion data; to ascertain instrumentation and control needs; to calculate heat balances for the incineration system; and to determine the feasibility of full waste-heat recovery and utilization, at the Frank E. Van Lare wastewater treatment plant.

  3. 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...

  4. Numerical simulation on heat transfer characteristics of the storage tank for concentrating solar power plant

    Directory of Open Access Journals (Sweden)

    Qianjun Mao

    2016-06-01

    Full Text Available Concentrating solar power plant coupling with energy storage is a new and emerging technology, which can solve two issues, that is, low flux density and intermittent of solar energy. Heat transfer characteristics of the storage tank in this system have a key effect on the system’s efficiency and cost. In this article, the heat transfer performance of a phase change thermal storage tank has been proposed, and the temperature distribution and liquid fraction of phase change material in the tank has numerically been investigated. The results show that the temperature increases with the increasing charge time. The results also show that there is a phase change process at the charge time of 200 min, and no phase change for the charge time of 250 and 300 min. The results of this article can provide a reference for future design and optimal operation of the storage tank in concentrating solar power plant.

  5. 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.

  6. 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

  7. Conservation potential at heating plants and cooling plants by means of regular jet plants; Einsparungspotential bei Heizungs- und Kaelteanlagen durch geregelte Strahlpumpen

    Energy Technology Data Exchange (ETDEWEB)

    Kilpper, Renate [W. Baelz und Sohn GmbH, Heilbronn (Germany)

    2009-12-15

    Regular jet pumps also are well-known as three-way injector valves. The employment of these regular jet pumps for the regulation of heating systems, ventilation systems and refrigerant plants in the industry and in the building engineering of hospitals, schools and administration buildings increases ever more. High savings of electricity and armatures are possible due to this technology. A selection of jet pumps with flange connections and sleeve connections is possible.

  8. 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.

  9. 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.

  10. 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...

  11. 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...

  12. 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.

  13. 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.

  14. 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.

  15. 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%.

  16. Performance investigation of a cogeneration plant with the efficient and compact heat recovery system

    Science.gov (United States)

    Myat, Aung; Thu, Kyaw; Kim, Young-Deuk; Choon, Ng Kim

    2012-06-01

    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%.

  17. Effect of heating strategy on power consumption and performance of a pilot plant anaerobic digester.

    Science.gov (United States)

    Espinosa-Solares, Teodoro; Valle-Guadarrama, Salvador; Bombardiere, John; Domaschko, Max; Easter, Michael

    2009-05-01

    The effect of heating strategy on power consumption and performance of a pilot plant anaerobic digester treating chicken litter, under thermophilic conditions, has been studied. Heating strategy was evaluated using three different spans (0.2 degrees C, 0.6 degrees C, and 1.0 degree C) for triggering the temperature control system from target temperature (56.7 degrees C). The hydraulic retention time in the pilot plant digester was in the range of 32 to 37 days, varying the total solids concentration fed from 5% to 6%. The results showed that under the experimental conditions, heating was the most energy-demanding process with 95.5% of the energy used. Increments up to 7.5% and 3.8%, respectively, on mechanical and heating power consumption, were observed as the span, for triggering the temperature control system from target temperature, was increased. Under the experimental conditions studied here, an increment of 30.6% on the global biodigester performance index was observed when a span of 1.0 degree C was compared to the one of 0.2 degrees C.

  18. 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

  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. CORRELATION ANALYSIS OF SURFACE TEMPERATURE OF ROOFTOPS, STREETSCAPES AND URBAN HEAT ISLAND EFFECT: CASE STUDY OF CENTRAL SYDNEY

    Directory of Open Access Journals (Sweden)

    Ehsan Sharifi

    2015-01-01

    Full Text Available Cities are frequently experiencing artificial heat stress, known as the Urban Heat Island (UHI effect. The UHI effect is commonly present in cities due to increased urbanization, where anthropogenic heat and human modifications have altered the characteristics of surfaces and atmosphere. Urban structure, land cover and metabolism are underlined as UHI key contributors and can result in higher urban densities being up to 10°C hotter compared to their peri-urban surroundings. The UHI effect increases the health-risk of spending time outdoors and boosts the need for energy consumption, particularly for air-conditioning during summer. Under investigation is what urban features are more resilient to the surface layer Urban Heat Island (sUHI effect in precinct scale. In the context of Sydney, this ongoing research aims to explore the most heat resilient urban features at precinct scale. This UHI investigation covers five highdensity precincts in central Sydney and is based on a nocturnal remote-sensing thermal image of central Sydney taken on 6 February 2009. Comparing the surface temperature of streetscapes and buildings’ rooftops (dominant urban horizontal surfaces, indicates that open spaces and particularly streetscapes are the most sensitive urban elements to the sUHI effect. The correlations between street network intensity, open space ratio, urban greenery ratio and the sUHI effect is being analysed in Sydney’s high-density precincts. Results indicate that higher open space ratio and street network intensity correlate significantly to higher sUHI effect at precinct scale. Meanwhile, 10% increase in the urban greenery can effectively decrease the precinct temperature by 0.6°C.

  1. 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

  2. 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)

  3. Heat flow and its coalbed gas effects in the central-south area of the Huaibei coalfield, eastern China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Based on an analysis of the present geo-temperature field and the thermal conductivity (K) of 62 samples from the central-south area of the Huaibei coalfield in eastern China, we calculated the heat flow and plotted its distribution map. The results show that the average heat flow in the research area is about 60 mW/m2. It is different from other major energy basins in the North China Plate, but has close relationship with the regional geology and the deep geological setting. The heat flow is comparatively higher in the southeastern, central, and northwestern areas than in the northeastern and southwestern areas. The geo-temperature distribution map of the bottom interface of the Permian coal measure was drawn by calculating its embedding depth and geo-temperature gradients. Finally, the present gas generation condition of the Permian coal measure is discussed by associating with the temperature condition, the vitrinite reflectance (Ro), the metamorphism of coal and tectonic-burial evolution. The study indicates all present characters of the Permian coal measure, such as lower present temperature, higher Ro value, middle-high rank coals, and uplift and extension events after the coal measure sediment, are favorable for the generation of secondary biogenic gas, but not thermogenic gas or primary biogenic gas.

  4. The Photovoltaic Heat Island Effect: Larger solar power plants increase local temperatures

    Science.gov (United States)

    Barron-Gafford, Greg A.; Minor, Rebecca L.; Allen, Nathan A.; Cronin, Alex D.; Brooks, Adria E.; Pavao-Zuckerman, Mitchell A.

    2016-01-01

    While photovoltaic (PV) renewable energy production has surged, concerns remain about whether or not PV power plants induce a “heat island” (PVHI) effect, much like the increase in ambient temperatures relative to wildlands generates an Urban Heat Island effect in cities. Transitions to PV plants alter the way that incoming energy is reflected back to the atmosphere or absorbed, stored, and reradiated because PV plants change the albedo, vegetation, and structure of the terrain. Prior work on the PVHI has been mostly theoretical or based upon simulated models. Furthermore, past empirical work has been limited in scope to a single biome. Because there are still large uncertainties surrounding the potential for a PHVI effect, we examined the PVHI empirically with experiments that spanned three biomes. We found temperatures over a PV plant were regularly 3–4 °C warmer than wildlands at night, which is in direct contrast to other studies based on models that suggested that PV systems should decrease ambient temperatures. Deducing the underlying cause and scale of the PVHI effect and identifying mitigation strategies are key in supporting decision-making regarding PV development, particularly in semiarid landscapes, which are among the most likely for large-scale PV installations. PMID:27733772

  5. Lifetime of solar collectors in solar heating plants; Levetid for solfangere i solvarmecentraler

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Z.; Fan, J.; Perers, B.; Furbo, S.

    2009-10-15

    Two HT solar collectors, which have been in operation at high temperature levels in Ottrupgaard solar heating plant for 15 years and in Marstal solar heating plant for 13 years, were in the spring of 2009 tested with regard to efficiency. The collectors were also inspected with the aim to evaluate the life time of the collectors. An old version of the HT solar collector, which has been in operation in a Swedish test facility since 1982, was tested with regard to the thermal performance. The measurements showed that the efficiencies of the solar collectors from the two Danish solar heating plants have been decreased since the installation. The reductions of the yearly thermal performance of the solar collectors are at a temperature level of 40 centigrade Celsius, 1% and 4%, respectively, for the Marstal collector and the Ottrupgaard collector. At a temperature level of 60 centigrade Celsius the reduction of the yearly thermal performance is 10% and 11%, respectively, for the Marstal collector and the Ottrupgaard collector. At a temperature level of 80 centigrade Celsius the reduction is 27% and 23%, respectively, for the Marstal collector and the Ottrupgaard collector. Based on the inspection, it is estimated that the reason for the reduction of thermal performance is the condition of the Teflon foil and the installation of the Teflon foil. The Teflon foil is wrinkled and folded and expanded in such a way that the distance between the absorber and the Teflon foil is far too small. Further, cracks in the Teflon foil have been observed. The thermal performance of the Swedish solar collector in the test facility is after 26 years of operation reduced compared to the thermal performance of the collector when it was first installed. For this collector the reduction in thermal performance is only 2-5%. The collectors from Ottrupgaard solar heating plant and from Marstal solar heating plant were in a very good condition with exception of the above mentioned problems with

  6. Investigations on a milk cooling plant with heat recovery. Untersuchungen an einer Milchkuehlanlage mit Waermerueckgewinnung

    Energy Technology Data Exchange (ETDEWEB)

    Loechel, E.; Bache, E. (Bitzer Kuehlmaschinenbau Schkeuditz GmbH (Germany))

    1991-01-01

    In the scope of an investigation program, the refrigeration technological, chemical, biological and sanitary prerequisites of milk cooling have been investigated. The condition was the cooling of 1000 l of milk in a milk cooling tub with a content of 2000 l. The cooling was realized in mechanical milkers according to DIN 8968 and ISO 5708. The tests began with a plant without accumulting the refrigerant in the heat recovery tank or without by-pass conduit from the compressor to the collector, which could be, however, retrofitted on demand. Based on the results received, additional measures have been ignored, since the profit bears no relation to the disadvantages (price of the plant, complexity of the control, incrase of the susceptibility and the leakage of the plant). The tests are carried out with R12 as well as with R22. (BWI).

  7. HISTORY AND DEVELOPMENT DIRECTIONS OF INDUCTION HEATING HFC AT THE MINSK AUTOMOBILE PLANT

    Directory of Open Access Journals (Sweden)

    P. S. Gurchenko

    2013-01-01

    Full Text Available The data on the development of induction technology in the Republic of Belarus on the example of the Minsk Automobile Plant are given. Their development began at the end of the fifties at the Minsk Tractor Plant, and the highest development has been obtained at the Minsk Automobile Plant from 1983 to 2008. The short features of energy-efficient processes created at MAZ in collaboration with country’s institutions are given: surface hardening on the contour of gear wheels, a body-surface-hardened gears and satellites, the impulse hardening of complex configuration, the heat treatment of long items and bulk materials, etc.Литература

  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. Impact of plant shoot architecture on leaf cooling: a coupled heat and mass transfer model.

    Science.gov (United States)

    Bridge, L J; Franklin, K A; Homer, M E

    2013-08-01

    Plants display a range of striking architectural adaptations when grown at elevated temperatures. In the model plant Arabidopsis thaliana, these include elongation of petioles, and increased petiole and leaf angles from the soil surface. The potential physiological significance of these architectural changes remains speculative. We address this issue computationally by formulating a mathematical model and performing numerical simulations, testing the hypothesis that elongated and elevated plant configurations may reflect a leaf-cooling strategy. This sets in place a new basic model of plant water use and interaction with the surrounding air, which couples heat and mass transfer within a plant to water vapour diffusion in the air, using a transpiration term that depends on saturation, temperature and vapour concentration. A two-dimensional, multi-petiole shoot geometry is considered, with added leaf-blade shape detail. Our simulations show that increased petiole length and angle generally result in enhanced transpiration rates and reduced leaf temperatures in well-watered conditions. Furthermore, our computations also reveal plant configurations for which elongation may result in decreased transpiration rate owing to decreased leaf liquid saturation. We offer further qualitative and quantitative insights into the role of architectural parameters as key determinants of leaf-cooling capacity.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. Robustness analysis of an air heating plant and control law by using polynomial chaos

    Energy Technology Data Exchange (ETDEWEB)

    Colón, Diego [University of São Paulo, Polytechnic School, LAC -PTC, São Paulo (Brazil); Ferreira, Murillo A. S.; Bueno, Átila M. [São Paulo State University - Sorocaba Campus, Sorocaba (Brazil); Balthazar, José M. [São Paulo State University - Rio Claro Campus, Rio Claro (Brazil); Rosa, Suélia S. R. F. de [University of Brasilia, Brasilia (Brazil)

    2014-12-10

    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.

  16. Efficiency of hepatitis A virus removal in six sewage treatment plants from central Tunisia.

    Science.gov (United States)

    Ouardani, Imen; Manso, Carmen F; Aouni, Mahjoub; Romalde, Jesús L

    2015-12-01

    The efficiency of six Tunisian sewage treatment plants (STP) for the removal of hepatitis A virus (HAV) from wastewater was analysed in order to evaluate the potential risk for human health linked to reuse or discharge of treated wastewater into the environment. The STP utilize different biological wastewater treatments including primary treatment, which involves the physical removal of organic and inorganic solids, and secondary treatment that involves different processes, such as activated sludge or lagoon. Quantitative real-time reverse transcription polymerase chain reaction (RT-PCR) and conventional RT-PCR were used for the analysis of the 325 wastewater samples (163 raw and 162 treated) obtained. Results revealed highest contamination in west-central of Tunisia in raw wastewater with 62.96 % of samples positive for HAV and predominance during winter and autumn, whereas east-central region showed 50.62 % of positive samples with high prevalence from winter through summer. The quantitative analysis revealed a range between 4.29 × 10(1) and 1.24 × 10(5) RNA copies/mL in treated wastewater, showing clearly the inefficiency for total removal of HAV regardless of the treatment method used. The vast majority of HAV sequences belonged to the sub-genotype IA, except one that was assigned to sub-genotype IB. PMID:26286509

  17. 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

  18. 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)

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. 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

  4. The market potential for solar heating plants in some European countries

    Energy Technology Data Exchange (ETDEWEB)

    Zinko, H; Bjaerklev, J.; Margen, P. [ZW Energiteknik AB, Nykoeping (Sweden)

    1996-03-01

    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 Mm{sup 2} for small systems, and 60 Mm{sup 2} 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 m{sup 2}/inhabitant in north and central Europe, and 0.5m{sup 2} 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

  5. Costs of urban area retrofit to district heating and cooling systems: north-central cities

    Energy Technology Data Exchange (ETDEWEB)

    Santini, D J; Davis, A A; Marder, S M

    1978-03-01

    This study considers the major urbanized areas of six U.S. cities (Washington, D.C.; St. Louis; Cleveland; Milwaukee; Detroit; Chicago) to arrive at reasonably accurate estimates of costs required to retrofit them with district heating and cooling systems. Only costs associated with heating and hot water are addressed here. Demand estimates and energy-supply analyses are made, and component capital costs are estimated to arrive at annualized system costs. Finally, a comparison of alternative energy-delivery options is made, and estimates of scarce-fuel savings are derived. 39 refs., 12 figs., 14 tables.

  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. 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.

  8. 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

  9. 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.

  10. 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....

  11. 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.

  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. Optimization of heating systems. Up on the way to a series-produced individual heating plant; Optimierung von Heizungssystemen. Auf dem Weg zur serienmaessig individuellen Heizungsanlage

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, R. [Bosch Thermotechnik GmbH, Wetzlar (Germany). Produktmanagement Buderus Deutschland

    2008-07-01

    Normal utilization grades of almost 110% referring to the lower heating value H-1 characterize modern thermal energy generators. However, the average yearly utilization rate of medium and larger heating plants only range at barely 70% according to a current analysis. An overall concept can provide remedy. The solution present in this contribution consists of modules that can be combined. These module contain all components like pumps, actuators, armatures, feeler and insulation. (orig.)

  14. 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

  15. Effect of volume loading on the Frank-Starling relation during reductions in central blood volume in heat-stressed humans

    DEFF Research Database (Denmark)

    Bundgaard-Nielsen, Morten; Wilson, T E; Seifert, Thomas;

    2010-01-01

    from whom pulmonary capillary wedge pressure (PCWP), central venous pressure and SV (via thermodilution) were obtained while central blood volume was reduced via lower-body negative pressure (LBNP) during normothermia, whole-body heating (increase in blood temperature 1 degrees C), and during whole-body...

  16. 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.

  17. 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...

  18. 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

  19. 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.

  20. 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.)

  1. Industrial and district heating plants in FR Yugoslavia as FBC technology market

    Energy Technology Data Exchange (ETDEWEB)

    Pavlovic, N.V.; Studovic, M. [Electric Power Industry of Serbia, Belgrade (Yugoslavia)

    1997-12-31

    The basic primary energy resource in Yugoslavia is lignite. As policy has already directed the substitution of the imported fuel with the domestic ones, Yugoslavia should turn towards wider use of lignite in district heating (DH) and industrial plants. This paper discusses the present state of technologies regarding boiler units installed in the industrial and DH sectors in Yugoslavia, as well as the assessment of potential market for FBC boilers. The paper also discusses limitations and circumstances of the introduction and larger FBC boilers` applications. 5 refs., 4 tabs.

  2. Using the sun and waste wood to heat a central Ohio home. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    The description of a house in Ohio built on a south facing slope with two levels above ground on the north, east, and west sides and three levels exposed to the southern winter Sun is presented. The floor plan, a general history of the project, the operation of the system, the backup heat source (wood), the collection of data, and the procedure for determining actual heat loss are described. Additionally, the calculation of the solar contribution percentage and the amount of mass to be included in the greenhouse and problems with an indirect gain wall are discussed. The location of the wood stove in the system is noted. The east wall temperature data are given. Soil temperature, air infiltration, thermal comfort, and energy usage are discussed. (MCW).

  3. 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)

  4. 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...

  5. WEATHER CONDITIONS OF MAIZE VEGETATION IN CONNECTION WITH THE PLANTING DATES IN THE ARID ZONE OF CENTRAL CISCAUCASUSIA

    Directory of Open Access Journals (Sweden)

    Kravchenko R. V.

    2016-02-01

    Full Text Available There were reviewed the results of the study of the dependence of main phenological phases of development of corn hybrids of different maturity groups of the selection of Krasnodar Research Institute of Agriculture named after P.P. Lukyanenko in the arid zone of Central Ciscaucasia (Ross 199, Ross 299, Krasnodar 382 and Krasnodar 410 and the AllRussian Research Institute of Corn (Mashuk 170, Newton, RIC 345 and Eric, as well as early-middle Rossiyskaya 1 from the changes of average daily air temperature of planting dates and preplant seed treatment by the preparation "TMTD-plus", containing the growth promoter called Krezatsin in its composition. The studies were conducted in accordance with the thematic plan of scientific researches of the department of crop and forage production of Stavropol State Agrarian University. The technology of maize growing on the experimental plot corresponds to the standard technology for this area and culture. The sowing was performed in three stages. The first (early sowing period was at t = + 7 ... +8 ° C. The second (recommended – was at t = + 10 ... + 12 ° C. The third (later sowing period was at t = +15 ° C. There was identified a high inverse correlation between the average daily air temperature and the duration of the intraphase periods of maize propagation. Thus, at the shifting of maize sowing dates with the second half of May on the second half of April we have optimization of heat regime in the generative period and rising of the efficiency of use of thermal resources of the region. There was marked the acceleration of development of corn seedlings when the average daily air temperatures was up to 12 ° C at the samples with the application of the disinfectant TMTD-plus

  6. 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.

  7. 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.

  8. 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)

  9. 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

  10. 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.

  11. 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

    2015-01-01

    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...

  12. 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.

  13. 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.

  14. 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

  15. 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 ...

  16. 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%.

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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 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...... 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...

  2. 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.

  3. 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.

  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. 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

  7. 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.

  8. Accumulation and Soil-to-Plant Transfer Factor of Lead and Manganese in some Plant Species in Semnan Province, Central Iran

    Directory of Open Access Journals (Sweden)

    Mohamad Sakizadeh

    2016-04-01

    Full Text Available Background: Heavy metals have detrimental effects on the health of human being. The values of manganese (Mn and lead (Pb in some plant species and soil samples in an arid area of Iran were evaluated in this study. Methods: The values of Pb and Mn in 94 plant samples from 8 plant species and the related soil samples in 2010 were considered in Shahroud and Damghan, central Iran. Moreover, the soil-to-plant transfer factors of these two elements were investigated. Results: Except for barley, the values of Pb in all of the considered plants were higher than the standard level of 0.3 mg/kg. The amounts of Mn in all of the plant species other than pistachio were higher than the standard level of 25 mg/kg. As a whole, the bio-concentration factor of Mn was higher than that of Pb in the study area. Conclusion: None of the soil-to-plant transfer factors exceeded one. Grape recorded the highest amounts of Pb and Mn compared with that of other investigated plant species. However, since its respective bio concentration factor (BCF was lower than one, it cannot be considered as a hyper accumulator of lead and manganese.

  9. 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.

  10. 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.

  11. Life management plants at nuclear power plants PWR; Planes de gestion de vida en centrales nucleares PWR

    Energy Technology Data Exchange (ETDEWEB)

    Esteban, G.

    2014-10-01

    Since in 2009 the CSN published the Safety Instruction IS-22 (1) which established the regulatory framework the Spanish nuclear power plants must meet in regard to Life Management, most of Spanish nuclear plants began a process of convergence of their Life Management Plants to practice 10 CFR 54 (2), which is the current standard of Spanish nuclear industry for Ageing Management, either during the design lifetime of the plant, as well as for Long-Term Operation. This article describe how Life Management Plans are being implemented in Spanish PWR NPP. (Author)

  12. Detection of carbon nanotubes in plant roots through microwave-induced heating

    Science.gov (United States)

    Irin, Fahmida; Shrestha, Babina; Canas, Jaclyn; Saed, Mohammad; Green, Micah

    2012-02-01

    We demonstrate a novel technique for quantitative detection of CNTs in biological samples by utilizing the thermal response of CNTs under microwave irradiation. In particular, rapid heating of CNTs due to microwave absorption was employed to quantify the amount of CNTs present in alfalfa plant roots. Alfalfa roots were prepared by injecting a known amount of CNTs (single walled and multi walled) and exposed to 30-50 W microwave power to generate calibration curves (temperature rise vs. CNT mass). These calibration curves serve as a characterization tool to determine the unknown amount of CNTs absorbed by alfalfa plant roots grown in CNT-laden soil with superior accuracy and sensitivity. Moreover, the threshold for detectable CNT concentration is much lower than common analytical methods of detecting nanomaterials, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. Considering the lack of effective detection methods for CNT uptake in plants, this method is not only unique but also practical, as it addresses a major problem in the field of nanotoxicology risk assessment.

  13. Modular pebble-bed reactor reforming plant design for process heat

    International Nuclear Information System (INIS)

    This report describes a preliminary design study of a Modular Pebble-Bed Reactor System Reforming (MPB-R) Plant. The system uses one pressure vessel for the reactor and a second pressure vessel for the components, i.e., reformer, steam generator and coolant circulator. The two vessels are connected by coaxial pipes in an arrangement known as the side-by-side (SBS). The goal of the study is to gain an understanding of this particular system and to identify any technical issues that must be resolved for its application to a modular reformer plant. The basic conditions for the MPB-R were selected in common with those of the current study of the MRS-R in-line prismatic fuel concept, specifically, the module core power of 250 MWt, average core power density of 4.1 w/cc, low enriched uranium (LEU) fuel with a 235U content of 20% homogeneously mixed with thorium, and a target burnup of 80,000 MWD/MT. Study results include the pebble-bed core neutronics and thermal-hydraulic calculations. Core characteristics for both the once-through-then-out (OTTO) and recirculation of fuel sphere refueling schemes were developed. The plant heat balance was calculated with 55% of core power allotted to the reformer

  14. Scale Resistant Heat Exchanger for Low Temperature Geothermal Binary Cycle Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Hays, Lance G. [Energent Corporation, Santa Ana, CA (United States)

    2014-11-18

    Phase 1 of the investigation of improvements to low temperature geothermal power systems was completed. The improvements considered were reduction of scaling in heat exchangers and a hermetic turbine generator (eliminating seals, seal system, gearbox, and lube oil system). A scaling test system with several experiments was designed and operated at Coso geothermal resource with brine having a high scaling potential. Several methods were investigated at the brine temperature of 235 ºF. One method, circulation of abradable balls through the brine passages, was found to substantially reduce scale deposits. The test heat exchanger was operated with brine outlet temperatures as low as 125 ºF, which enables increased heat input available to power conversion systems. For advanced low temperature cycles, such as the Variable Phase Cycle (VPC) or Kalina Cycle, the lower brine temperature will result in a 20-30% increase in power production from low temperature resources. A preliminary design of an abradable ball system (ABS) was done for the heat exchanger of the 1 megawatt VPC system at Coso resource. The ABS will be installed and demonstrated in Phase 2 of this project, increasing the power production above that possible with the present 175 ºF brine outlet limit. A hermetic turbine generator (TGH) was designed and manufacturing drawings produced. This unit will use the working fluid (R134a) to lubricate the bearings and cool the generator. The 200 kW turbine directly drives the generator, eliminating a gearbox and lube oil system. Elimination of external seals eliminates the potential of leakage of the refrigerant or hydrocarbon working fluids, resulting in environmental improvement. A similar design has been demonstrated by Energent in an ORC waste heat recovery system. The existing VPC power plant at Coso was modified to enable the “piggyback” demonstration of the TGH. The existing heat exchanger, pumps, and condenser will be operated to provide the required

  15. Central model predictive control of a group of domestic heat pumps, case study for a small district

    NARCIS (Netherlands)

    Leeuwen, van R.P.; Fink, J.; Smit, G.J.M.; Helfert, Markus; Krempels, Karl-Heinz; Donnellan, Brian; Klein, Cornel

    2015-01-01

    In this paper we investigate optimal control of a group of heat pumps. Each heat pump provides space heating and domestic hot water to a single household. Besides a heat pump, each house has a buffer for domestic hot water and a floor heating system for space heating. The paper describes models and

  16. Integration of biomass fast pyrolysis and precedent feedstock steam drying with a municipal combined heat and power plant

    International Nuclear Information System (INIS)

    Biomass fast pyrolysis (BFP) is a promising pre-treatment technology for converting biomass to transport fuel and in the future also for high-grade chemicals. BFP can be integrated with a municipal combined heat and power (CHP) plant. This paper shows the influence of BFP integration on a CHP plant's main parameters and its effect on the energetic and environmental performance of the connected district heating network. The work comprises full- and part-load operation of a CHP plant integrated with BFP and steam drying. It also evaluates different usage alternatives for the BFP products (char and oil). The results show that the integration is possible and strongly beneficial regarding energetic and environmental performance. Offering the possibility to provide lower district heating loads, the operation hours of the plant can be increased by up to 57%. The BFP products should be sold rather than applied for internal use as this increases the district heating network's primary energy efficiency the most. With this integration strategy future CHP plants can provide valuable products at high efficiency and also can help to mitigate global CO2 emissions. - Highlights: • Part load simulation of a cogeneration plant integrated with biomas fast pyrolysis. • Analysis of energetic and environmental performance. • Assessment of different uses of the pyrolysis products

  17. On the performance of CSP oil-cooled plants, with and without heat storage in tanks of molten salts

    International Nuclear Information System (INIS)

    The most-used thermodynamic CSP (concentrating solar plants) in the world, provided with linear parabolic collectors cooled by oil, have been analyzed in the two configurations employed: with heat storage in two tanks filled with molten salts and without heat storage. The performances and the costs of the plants have been analyzed in the paper according to solar multiple (ranging between 1 and 3) and to storage capacity (ranging between 0 and 24 h), in terms of annual electrical energy, average annual plant efficiency, charge factor, capital cost and levelized cost of energy (LCOE). Also a method of economic optimization, based on the evaluation of the minimum value of the levelized cost of energy is presented. The minimum LCOE value, in the case of heat storage, is obtained for a solar multiple of 2.2 and a storage capacity of 16 h. In the plants without storage, minimum LCOE is achieved for SM (solar multiple) equal to 1.2. - Highlights: • A model to analyze the performance of oil thermodynamic solar plant is presented. • Plants without heat storage and with storage in molten salts are considered. • Annual electricity production, efficiency, capital cost, CF and LCOE are estimated. • Storage capacity and solar multiple values which minimize LCOE have been found

  18. A thermodynamic analysis of waste heat recovery from reciprocating engine power plants by means of Organic Rankine Cycles

    International Nuclear Information System (INIS)

    Organic Rankine Cycle (ORC) is a Rankine cycle using organic fluid as the working fluid instead of water and steam. The ORC process is a feasible choice in waste heat recovery applications producing electricity from relatively low-temperature waste heat sources or in applications having a rather low power output. Utilizing waste heat from a large high-efficiency reciprocating engine power plant with ORC processes is studied by means of computations. In addition to exhaust gas heat recovery, this study represents and discusses an idea of directly replacing the charge air cooler (CAC) of a large turbocharged engine with an ORC evaporator to utilize the charge air heat in additional power production. A thermodynamic analysis for ORCs was carried out with working fluids toluene, n-pentane, R245fa and cyclohexane. The effect of different ORC process parameters on the process performance are presented and analyzed in order to investigate the heat recovery potential from the exhaust gas and charge air. A simplified feasibility consideration is included by comparing the ratio of the theoretical heat transfer areas needed and the obtained power output from ORC processes. The greatest potential is related to the exhaust gas heat recovery, but in addition also the lower temperature waste heat streams could be utilized to boost the electrical power of the engine power plant. A case study for a large-scale gas-fired engine was carried out showing that the maximum power increase of 11.4% was obtained from the exhaust gas and 2.4% from the charge air heat. - Highlights: • Waste heat recovery potential of reciprocating engines was studied. • Thermodynamic optimization for ORCs was carried out with different fluids. • The utilization of exhaust gas and charge air heat is presented and discussed. • Simplified economic feasibility study was included in the analysis. • Power increase of 11.4% was obtained from exhaust gas and 2.4% from charge air

  19. Energy-effective method for low-temperature deaeration of make-up water on the heating supply system of heat power plants

    Science.gov (United States)

    Sharapov, V. I.; Pazushkina, O. V.; Kudryavtseva, E. V.

    2016-01-01

    The technology for low-temperature deaeration of make-up water of heating supply systems is developed that makes it possible to substantially enhance the energy efficiency of heat power plants (HPPs). As a desorbing agent for deaeration of make-up water of heating supply systems, it is proposed to use not steam or superheated water but a gas supplied to boiler burners. Natural gas supplied to steam boilers of HPPs has very low or often negative temperature after reducing devices. At the same time, it is virtually corrosive gas-free (oxygen and carbon dioxide) and, therefore, can be successfully used as the desorbing agent for water deaeration. These factors make it possible to perform deaeration of make-up water of heating supply systems at relatively low temperatures (10-30°C). Mixing of the cold deaerated make-up water with the return delivery water results in a significant decrease in the temperature the return delivery water before a lower delivery heater of a dual-purpose turbine plant, increase in the power output with the heat consumption, and, consequently, enhancement in the operation efficiency of the HPP. The article presents the calculation of the consumption of gas theoretically required for deaeration and reveals the evaluation of the energy efficiency of the technology for a typical energy unit of thermal power station. The mass transfer efficiency of the deaeration of the make-up water of heating supply systems is estimated for the case of using natural gas as the desorbing agent for which the specific gas consumption required theoretically for deaeration is calculated. It is shown that the consumption of natural gas used as fuel in boilers of HPPs is sufficient for the deaeration of any volumes of the make-up water of heating supply systems. The energy efficiency of the developed technology is evaluated for a typical heat power-generating unit of the HPP with a T-100-12.8 turbine. The calculation showed that the application of the new technology

  20. Ground-water temperature of the Wyoming quadrangle in central Delaware : with application to ground-water-source heat pumps

    Science.gov (United States)

    Hodges, Arthur L.

    1982-01-01

    Ground-water temperature was measured during a one-year period (1980-81) in 20 wells in the Wyoming Quadrangle in central Delaware. Data from thermistors set at fixed depths in two wells were collected twice each week, and vertical temperature profiles of the remaining 18 wells were made monthly. Ground-water temperature at 8 feet below land surface in well Jc55-1 ranged from 45.0 degrees F in February to 70.1 degrees F in September. Temperature at 35 feet below land surface in the same well reached a minimum of 56.0 degrees F in August, and a maximum of 57.8 degrees F in February. Average annual temperature of ground water at 25 feet below land surface in all wells ranged from 54.6 degrees F to 57.8 degrees F. Variations of average temperature probably reflect the presence or absence of forestation in the recharge areas of the wells. Ground-water-source heat pumps supplied with water from wells 30 or more feet below land surface will operate more efficiently in both heating and cooling modes than those supplied with water from shallower depths. (USGS)

  1. Comparative analysis of cooling systems for energy equipment of combined heat and power plants and nuclear power plants

    Science.gov (United States)

    Reutov, B. F.; Lazarev, M. V.; Ermakova, S. V.; Zisman, S. L.; Kaplanovich, L. S.; Svetushkov, V. V.

    2016-07-01

    In the 20th century, the thermal power engineering in this country was oriented toward oncethrough cooling systems. More than 50% of the CHPP and NPP capacities with once-through cooling systems put into operation before the 1990s were large-scale water consumers but with minimum irretrievable water consumption. In 1995, the Water Code of the Russian Federation was adopted in which restrictions on application of once-through cooling systems for newly designed combined heat and power plants (CHPPs) were introduced for the first time. A ban on application of once-through systems was imposed by the current Water Code of the Russian Federation (Federal law no. 74-FZ, Art. 60 Cl. 4) not only for new CHPPs but also for those to be modified. Clause 4 of Article 60 of the Water Code of the Russian Federation contravenes law no. 7-FZ "On Protection of the Environment" that has priority significance, since the water environment is only part of the natural environment and those articles of the Water Code of the Russian Federation that are related directly to electric power engineering, viz., Articles 46 and 62. In recent decades, the search for means to increase revenue charges and the economic pressure on the thermal power industry caused introduction by law of charges for use of water by cooling systems irrespective of the latter's impact on the water quality of the source, the environment, the economic efficiency of the power production, and the living conditions of the people. The long-range annual increase in the water use charges forces the power generating companies to switch transfer once-through service water supply installations to recirculating water supply systems and once-through-recirculating systems with multiple reuse of warm water, which drastically reduces the technical, economic, and ecological characteristic of the power plant operation and also results in increasing power rates for the population. This work comprehensively substantiates the demands of

  2. Dense gas in the Galactic central molecular zone is warm and heated by turbulence

    CERN Document Server

    Ginsburg, Adam; Ao, Yiping; Riquelme, Denise; Kauffmann, Jens; Pillai, Thushara; Mills, Elisabeth A C; Requena-Torres, Miguel A; Immer, Katharina; Testi, Leonardo; Ott, Juergen; Bally, John; Battersby, Cara; Darling, Jeremy; Aalto, Susanne; Stanke, Thomas; Kendrew, Sarah; Kruijssen, J M Diederik; Longmore, Steven; Dale, James; Guesten, Rolf; Menten, Karl M

    2016-01-01

    The Galactic center is the closest region in which we can study star formation under extreme physical conditions like those in high-redshift galaxies. We measure the temperature of the dense gas in the central molecular zone (CMZ) and examine what drives it. We mapped the inner 300 pc of the CMZ in the temperature-sensitive J = 3-2 para-formaldehyde (p-H$_2$CO) transitions. We used the $3_{2,1} - 2_{2,0} / 3_{0,3} - 2_{0,2}$ line ratio to determine the gas temperature in $n \\sim 10^4 - 10^5 $cm$^{-3}$ gas. We have produced temperature maps and cubes with 30" and 1 km/s resolution and published all data in FITS form. Dense gas temperatures in the Galactic center range from ~60 K to > 100 K in selected regions. The highest gas temperatures T_G > 100 K are observed around the Sgr B2 cores, in the extended Sgr B2 cloud, the 20 km/s and 50 km/s clouds, and in "The Brick" (G0.253+0.016). We infer an upper limit on the cosmic ray ionization rate ${\\zeta}_{CR} < 10^{-14}$ 1/s. The dense molecular gas temperature o...

  3. Central radio galaxies in groups: cavities, bubbles and the history of AGN heating

    Science.gov (United States)

    Giacintucci, S.; Venturi, T.; Raychaudhury, S.; Vrtilek, J.

    2008-10-01

    E' noto che le regioni centrali degli ammassi e gruppi di galassie costituiscono un ambiente in cui gas caldo e plasma radioemittente proveniente dalle galassie dominanti interagiscono tra loro. In particolare, si pensa che la radioemissione dell'AGN centrale ed i suoi possibili cicli di attivita', siano strettamente legati alla presenza di cavita' e "bubbles" nel gas intergalattico. Si presentera' lo status di un progetto osservativo effettuato con il Giant Metrewave Radio Telescope (GMRT, India) su di un campione di 18 gruppi di galassie, osservati a tre frequenze radio (235 MHz, 325 MHz e 610 MHz). Lo studio della morfologia radio degli AGN centrali e la relativa analisi spettrale permettono di ottenere stime sull'eta' di questi oggetti, e sulla loro energia totale, che a loro volta sono in relazione con le proprieta' X dei gruppi stessi. Per tutti gli oggetti del campione sono disponibili osservazioni Chandra di proprieta'. Per due oggetti del campione, 4C+24.36 (al centro di AWM04) e NGC741 (al centro di RSOG17) verra' presentato uno studio dettagliato.

  4. Theoretical analysis and numerical modeling of heat transfer and fuel migration in underlying soils and constructive elements of nuclear plants during an accident release from the core

    International Nuclear Information System (INIS)

    Migration of fuel fragments and core fission products during severe accidents on nuclear plants is studied analytically and numerically.The problems of heat transfer and migration of volume heat sources in construction materials and underlying soils are considered

  5. The combined effect of salinity and heat reveals a specific physiological, biochemical and molecular response in tomato plants.

    Science.gov (United States)

    Rivero, Rosa M; Mestre, Teresa C; Mittler, Ron; Rubio, Francisco; Garcia-Sanchez, Francisco; Martinez, Vicente

    2014-05-01

    Many studies have described the response mechanisms of plants to salinity and heat applied individually; however, under field conditions some abiotic stresses often occur simultaneously. Recent studies revealed that the response of plants to a combination of two different stresses is specific and cannot be deduced from the stresses applied individually. Here, we report on the response of tomato plants to a combination of heat and salt stress. Interestingly, and in contrast to the expected negative effect of the stress combination on plant growth, our results show that the combination of heat and salinity provides a significant level of protection to tomato plants from the effects of salinity. We observed a specific response of plants to the stress combination that included accumulation of glycine betaine and trehalose. The accumulation of these compounds under the stress combination was linked to the maintenance of a high K(+) concentration and thus a lower Na(+) /K(+) ratio, with a better performance of the cell water status and photosynthesis as compared with salinity alone. Our findings unravel new and unexpected aspects of the response of plants to stress combination and provide a proposed list of enzymatic targets for improving crop tolerance to the abiotic field environment.

  6. Atucha I nuclear power plant: repair works in QK02W01 moderator system heat exchanger

    International Nuclear Information System (INIS)

    Atucha I nuclear power plant moderator system operates with highly radioactive heavy water, a pressure of 115 Bar and temperatures of about 200 C degrees. In March 2000, an increasing leakage of heavy water to the conventional thermal circuit was detected, conducting the plant to a shut down. The development of a number of actions and measures were taken, in order to plug this leakage. The leakage was found in a heat exchanger, which is located in a place of difficult access, with a high radiological yield and which, according to design, it was not considered to be mechanically repaired. It is a U bend tubes heat exchanger, weighting about 20 tons, and with a heavy water flow of 800 tons/h on the primary circuit, and 950 tons/h of ordinary water on the secondary side. Foreseeing this event, it had been designed and constructed special equipment and procedures, by means of a contract, with the Company INVAP SA. Repair works were carried out within a period of eighty-six (86) days, from which, forty five days were used to repair the component itself. A considerable amount of time was used to prepare simulators and the training of personnel. Due to the high radiological yield and the strict care of radiological standards, it was necessary the participation of 300 persons, integrating a collective dose of 4,86 Sv-m. It was necessary the construction of platforms and auxiliary stairs so as to make the work place accessible, as well as lifting and movement devices for heavy components, since this area does not have such kind of facilities. Welding and cutting machines remote controlled as well as manipulators which operated in front of the exchanger tube sheet were used. The aim was the reduction of dose values as much as possible. Special shielding were developed and in some cases it was necessary the adoption of drastic measures such as the cutting of bolts or pipes. The failure was detected and the tube was plugged. Also were plugged those tubes with wall thickness

  7. Optimal Design of Cogeneration Systems in Industrial Plants Combined with District Heating/Cooling and Underground Thermal Energy Storage

    Directory of Open Access Journals (Sweden)

    Vincenzo Dovì

    2011-12-01

    Full Text Available Combined heat and power (CHP systems in both power stations and large plants are becoming one of the most important tools for reducing energy requirements and consequently the overall carbon footprint of fundamental industrial activities. While power stations employ topping cycles where the heat rejected from the cycle is supplied to domestic and industrial consumers, the plants that produce surplus heat can utilise bottoming cycles to generate electrical power. Traditionally the waste heat available at high temperatures was used to generate electrical power, whereas energy at lower temperatures was either released to the environment or used for commercial or domestic heating. However the introduction of new engines, such as the ones using the organic Rankine cycle, capable of employing condensing temperatures very close to the ambient temperature, has made the generation of electrical power at low temperatures also convenient. On the other hand, district heating is becoming more and more significant since it has been extended to include cooling in the warm months and underground storage of thermal energy to cope with variable demand. These developments imply that electric power generation and district heating/cooling may become alternative and not complementary solutions for waste energy of industrial plants. Therefore the overall energy management requires the introduction of an optimisation algorithm to select the best strategy. In this paper we propose an algorithm for the minimisation of a suitable cost function, for any given variable heat demand from commercial and domestic users, with respect to all independent variables, i.e., temperatures and flowrates of warm fluid streams leaving the plants and volume and nature of underground storage. The results of the preliminary process integration analysis based on pinch technology are used in this algorithm to provide bounds on the values of temperatures.

  8. Next Generation Nuclear Plant Intermediate Heat Exchanger Materials Research and Development Plan (PLN-2804)

    Energy Technology Data Exchange (ETDEWEB)

    J. K. Wright

    2008-04-01

    DOE has selected the High Temperature Gas-cooled Reactor (HTGR) design for the Next Generation Nuclear Plant (NGNP) Project. The NGNP will demonstrate the use of nuclear power for electricity and hydrogen production. It will have an outlet gas temperature in the range of 900°C and a plant design service life of 60 years. The reactor design will be a graphite moderated, helium-cooled, prismatic or pebble-bed reactor and use low-enriched uranium, Tri-Isotopic (TRISO)-coated fuel. The plant size, reactor thermal power, and core configuration will ensure passive decay heat removal without fuel damage or radioactive material releases during accidents. The NGNP Materials Research and Development (R&D) Program is responsible for performing R&D on likely NGNP materials in support of the NGNP design, licensing, and construction activities. Today’s high-temperature alloys and associated ASME Codes for reactor applications are approved up to 760°C. However, some primary system components, such as the Intermediate Heat Exchanger (IHX) for the NGNP will require use of materials that can withstand higher temperatures. The thermal, environmental, and service life conditions of the NGNP will make selection and qualification of some high-temperature materials a significant challenge. Examples include materials for the core barrel and core internals, such as the control rod sleeves. The requirements of the materials for the IHX are among the most demanding. Selection of the technology and design configuration for the NGNP must consider both the cost and risk profiles to ensure that the demonstration plant establishes a sound foundation for future commercial deployments. The NGNP challenge is to achieve a significant advancement in nuclear technology while at the same time setting the stage for an economically viable deployment of the new technology in the commercial sector soon after 2020. A number of solid solution strengthened nickel based alloys have been considered for

  9. Next Generation Nuclear Plant Steam Generator and Intermediate Heat Exchanger Materials Research and Development Plan

    Energy Technology Data Exchange (ETDEWEB)

    J. K. Wright

    2010-09-01

    DOE has selected the High Temperature Gas-cooled Reactor (HTGR) design for the Next Generation Nuclear Plant (NGNP) Project. The NGNP will demonstrate the use of nuclear power for electricity and hydrogen production. It will have an outlet gas temperature in the range of 900°C and a plant design service life of 60 years. The reactor design will be a graphite moderated, helium-cooled, prismatic or pebble-bed reactor and use low-enriched uranium, Tri-Isotopic (TRISO)-coated fuel. The plant size, reactor thermal power, and core configuration will ensure passive decay heat removal without fuel damage or radioactive material releases during accidents. The NGNP Materials Research and Development (R&D) Program is responsible for performing R&D on likely NGNP materials in support of the NGNP design, licensing, and construction activities. Today’s high-temperature alloys and associated ASME Codes for reactor applications are approved up to 760°C. However, some primary system components, such as the Intermediate Heat Exchanger (IHX) for the NGNP will require use of materials that can withstand higher temperatures. The thermal, environmental, and service life conditions of the NGNP will make selection and qualification of some high-temperature materials a significant challenge. Examples include materials for the core barrel and core internals, such as the control rod sleeves. The requirements of the materials for the IHX are among the most demanding. Selection of the technology and design configuration for the NGNP must consider both the cost and risk profiles to ensure that the demonstration plant establishes a sound foundation for future commercial deployments. The NGNP challenge is to achieve a significant advancement in nuclear technology while at the same time setting the stage for an economically viable deployment of the new technology in the commercial sector soon after 2020. A number of solid solution strengthened nickel based alloys have been considered for

  10. Elecnuc. Nuclear power plants in the world; Elecnuc. Les centrales nucleaires dans le monde

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    This 2003 version of Elecnuc contents information, data and charts on the nuclear power plants in the world and general information on the national perspectives concerning the electric power industry. The following topics are presented: 2002 highlights; characteristics of main reactor types and on order; map of the French nuclear power plants; the worldwide status of nuclear power plants on 2002/12/3; units distributed by countries; nuclear power plants connected to the Grid by reactor type groups; nuclear power plants under construction; capacity of the nuclear power plants on the grid; first electric generations supplied by a nuclear unit; electrical generation from nuclear plants by country at the end 2002; performance indicator of french PWR units; trends of the generation indicator worldwide from 1960 to 2002; 2002 cumulative Load Factor by owners; nuclear power plants connected to the grid by countries; status of license renewal applications in Usa; nuclear power plants under construction; Shutdown nuclear power plants; exported nuclear power plants by type; exported nuclear power plants by countries; nuclear power plants under construction or order; steam generator replacements; recycling of Plutonium in LWR; projects of MOX fuel use in reactors; electricity needs of Germany, Belgium, Spain, Finland, United Kingdom; electricity indicators of the five countries. (A.L.B.)

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

    International Nuclear Information System (INIS)

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

  12. The cost of installing central heating. Comparison of Norway and Sweden. Final version; Kostnader ved installasjon av vannbaaren varme. Sammenlikning av Norge og Sverige. Endelig versjon

    Energy Technology Data Exchange (ETDEWEB)

    Haarberg, Karl Johan; Elnan, Kaare; Essen, Jan von; Hovden, Agnete; Ekvall, Thomas; Melbaeck, Johan

    2010-10-22

    The objective of the cost study is to examine costs and cost differences associated with the installation of various technical solutions for water heating in various buildings in Norway and Sweden - regionally and nationally. In addition, the cost study intended to point out any barriers to the increased prevalence of central heating, as well as proposals for measures to remove such. Finally, the cost study in general and in particular barriers placed in a larger environment and climate perspective. (AG)

  13. A central role for bifunctional aspartate/prephenate aminotransferase in the biosynthesis of amino acids in plant plastids.

    OpenAIRE

    El-Azaz, Jorge; Cánovas, Francisco M.; de la Torre, Fernando; Ávila, Concepción

    2014-01-01

    A central role for bifunctional aspartate/prephenate aminotransferase in the biosynthesis of amino acids in plant plastids. Fernando de la Torre, Jorge El-Azaz, Concepción Ávila, Francisco M. Cánovas Departamento de Biología Molecular y Bioquímica. Universidad de Málaga. Bifunctional aspartate/prephenate aminotransferases (AAT/PAT) are plastid-located enzymes encoded by a single locus in all reported plants, which develop two different enzymatic activities: aspartate aminotransferas...

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

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.; Moisseytsev, A.; Majumdar, S.; Shankar, P. S.; Nuclear Engineering Division

    2007-04-05

    The Next Generation Nuclear Plant (NGNP), which is an advanced high temperature gas reactor (HTGR) concept 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 900-1000 C. In the indirect cycle system, an intermediate heat exchanger is used to transfer the heat from primary helium from the core to the secondary fluid, which can be helium, nitrogen/helium mixture, or a molten salt. The system concept for the vary high temperature reactor (VHTR) can be a reactor based on the prismatic block of the GT-MHR developed by a consortium led by General Atomics in the U.S. or based on the PBMR design developed by ESKOM of South Africa and British Nuclear Fuels of U.K. This report has made a preliminary assessment on the issues pertaining to the intermediate heat exchanger (IHX) for the NGNP. Two IHX designs namely, shell and tube and compact heat exchangers were considered in the assessment. Printed circuit heat exchanger, among various compact heat exchanger (HX) designs, was selected for the analysis. Irrespective of the design, the material considerations for the construction of the HX are essentially similar, except may be in the fabrication of the units. As a result, we have reviewed in detail the available information on material property data relevant for the construction of HX and made a preliminary assessment of several relevant factors to make a judicious selection of the material for the IHX. The assessment included four primary candidate alloys namely, Alloy 617 (UNS N06617), Alloy 230 (UNS N06230), Alloy 800H (UNS N08810), and Alloy X (UNS N06002) for the IHX. Some of the factors addressed in this report are the tensile, creep, fatigue, creep fatigue, toughness properties for the candidate alloys, thermal aging effects on the mechanical properties, American Society of Mechanical Engineers (ASME) Code compliance

  15. Impact of different national biomass policies on investment costs of biomass district heating plants. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-04-01

    The BIO-COST project - co-ordinated by E.V.A. - was funded by the European Commission's THERMIE Type B Programme. The objective of BIO-COST was to analyse the impact of national biomass policies on the investment costs of biomass district heating (DH) plants. The European comparison should help identifying measures to reduce investment costs for biomass DH plants and/or components down to a 'best practice' level. The investigation is based on the comparison of 20 biomass DH plants by country, with Denmark and Sweden having mainly high energy taxes as driver, while Austria and France rely mainly on subsidy systems. The results of BIO-COST show, that governmental policies can have a big impact especially on grid and buildings costs, effecting of course the overall costs of the plant enormously. Emission standards have their effects especially on the costs for technical equipment, however, this fact was not reflected in the BIO-COST data. The results do not show a clear advantage of either the energy tax approach or the subsidy approach: The French subsidy approach leads to fairly low cost levels compared to the Danish tax approach, while the Swedish tax approach seems to yield the lowest cost level. On the other hand the Austrian subsidy approach seems to intercrease investment costs. In principle both the tax as the subsidy approach can lead to the same effect: a project is calculated in such a way, that it just meets economic breakeven. This is typically the case when the project is not carried out by a private enterprise but by an operator aiming at enhanced public welfare (e.g. co-operative, municipality). In this case a subsidy model might yield more possibilities to encourage an economically efficient development, than a tax. Instead of giving subsidies as a fixed percentage of investments they could be adjusted to the actual needs of the project as proven by a standardised calculation. Of course this can create the incentive to expect higher

  16. District heating and cooling systems for communities through power plant retrofit and distribution network, City of Piqua, Ohio

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-09-18

    The goal of the Piqua, Ohio District Heating and Cooling Demonstration Project is to demonstrate the feasibility and efficiency of using cogenerated thermal energy from the City's Municipal Power Plant to provide residential, commercial and industrial space heating and cooling and satisfy other community energy needs as appropriate. Progress in four tasks within this project is reported. These tasks include: development of team work plan resource allocation; identification of thermal energy source market; analysis of energy market; and planning of power plant retrofits. (LCL)

  17. Endangered and threatened plant species of the Nevada Test Site, Ash Meadows, and central-southern Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Beatley, J.C.

    1977-07-01

    Three plant species included among the Nevada Threatened or Endangered Flora of the Federal Register list of July 1, 1975, were omitted from the recent reports dealing with these groups of plants in central-southern Nevada. Two of the species, Ephedra funerea and Mirabilis pudica, were not included because they are both widely distributed and locally common in southern Nevada and were understood (unofficially) to be no longer considered candidates for either an Endangered or Threatened status. The third species, Machaeranthera ammophila, is now included with M. arida, an uncommon species of central and eastern Mojave Desert of southern California (to southern Nevada, Arizona, and Sonora), and is therefore no longer a candidate for the status of Threatened Species in Nevada.

  18. Arsenic contamination in soil-water-plant (rice, Oryza sativa L.) continuum in central and sub-mountainous Punjab, India.

    Science.gov (United States)

    Sidhu, Savitoz Singh; Brar, Joginder Singh; Biswas, Asim; Banger, Kamaljit; Saroa, Gurbachan Singh

    2012-11-01

    In the present study, Arsenic (As) concentrations in underground water, soil, and plants (rice) and their inter-relationships in central and sub-mountainous Punjab, India were studied. Approximately, 32% of the tubewell water samples had As concentrations greater than the maximum permissible limit (10 μg As L(-1)) set by the World Health Organization (WHO) whereas in hand pump waters, As concentrations were within the safe range (i.e. soil (r = 0.57; P < 0.05) and plant samples (r = 0.27-0.82; P < 0.05) in central and sub-mountainous Punjab. The estimated daily intake of As through human consumption in rural and urban population was 0.016 and 0.012 μg day(-1) kg(-1) body weight respectively. PMID:22926503

  19. 2013 Annual Wastewater Reuse Report for the Idaho National Laboratory Site’s Central Facilities Area Sewage Treatment Plant

    Energy Technology Data Exchange (ETDEWEB)

    Mike Lewis

    2014-02-01

    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, 2012, through October 31, 2013. The report contains, as applicable, 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 2013 permit year, no wastewater was land-applied to the irrigation area of the Central Facilities Area Sewage Treatment Plant and therefore, no effluent flow volumes or samples were collected from wastewater sampling point WW-014102. However, soil samples were collected in October from soil monitoring unit SU-014101.

  20. THE CENTRAL ROLES OF IRON AND CALCIUM FOR PLANT/MICROBE INTERACTION AND SHAPING MICROBIAL COMMUNITIES IN THE SOIL

    Directory of Open Access Journals (Sweden)

    Irena Sherameti

    2010-12-01

    Full Text Available Roots are associated with a large number of different microbes, which can form beneficial, neutral or pathogenic interactions. “Infochemicals” from the microbial community, released into the soil or plants, induce signaling processes in the root cells which determine the fitness of a plant and its response to the environment. The plant integrates the information from the different microbes for an appropriate and balanced response. On the other hand, the microbial community is shaped by signals from the roots. We have established a symbiotic interaction system, in which the information exchange between the model plant Arabidopsis thaliana and a beneficial, plant-growth promoting endophytic fungus, called Piriformospora indica, can be studied and compared with other root-interacting microbes. Biochemical and molecular-genetic data indicate that two ions, calcium and iron, are major players in determining the fitness of the plant and the response to microbial signals. We will highlight the central role of these two ions in plant/microbe interactions.

  1. Analyzing the possibility of constructing the air heating system for an integrated solid fuel gasification combined-cycle power plant

    Science.gov (United States)

    Mikula, V. A.; Ryzhkov, A. F.; Val'tsev, N. V.

    2015-11-01

    Combined-cycle power plants operating on solid fuel have presently been implemented only in demonstration projects. One of possible ways for improving such plants consists in making a shift to hybrid process circuits of integrated gasification combined-cycle plants with external firing of solid fuel. A high-temperature air heater serving to heat compressed air is a key element of the hybrid process circuit. The article describes application of a high-temperature recuperative metal air heater in the process circuit of an integrated gasification combined-cycle power plant (IGCC). The available experience with high-temperature air heating is considered, and possible air heater layout arrangements are analyzed along with domestically produced heat-resistant grades of steel suitable for manufacturing such air heater. An alternative (with respect to the traditional one) design is proposed, according to which solid fuel is fired in a noncooled furnace extension, followed by mixing the combustion products with recirculation gases, after which the mixture is fed to a convective air heater. The use of this design makes it possible to achieve considerably smaller capital outlays and operating costs. The data obtained from thermal and aerodynamic calculations of the high-temperature air heater with a thermal capacity of 258 MW for heating air to a temperature of up to 800°C for being used in the hybrid process circuit of a combined-cycle power plant are presented.

  2. District heating and cooling systems for communities through power plant retrofit and distribution network. Final report. Volume I. Text

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-09-15

    An analysis was performed investigating the potential of retrofitting Detroit Edison's Conners Creek power plant to supply district heating and cooling to an area surrounding the plant and within the City of Detroit. A detailed analysis was made of the types and ages of the buildings in the service area as a basis for establishing loads. The analysis of the power plant established possible modifications to the turbines to serve the load in the area. Based upon the service area data and plant retrofit schemes, a distribution system was developed incrementally over a 20-y period. An economic analysis of the system was performed to provide cash flows and payback periods for a variety of energy costs, system costs, and escalation rates to determine the economic viability of the system analyzed. The legal and regulatory requirements required of the district heating and cooling system owner in Michigan were also analyzed to determine what conditions must be met to own and operate the system.

  3. Occurrence of pharmaceuticals in municipal wastewater treatment plants and receiving surface waters in Central and Southern Finland

    OpenAIRE

    Lindholm-Lehto, Petra

    2016-01-01

    The presence of five selected pharmaceuticals, four anti-inflammatory drugs, diclofenac, ibuprofen, ketoprofen, naproxen, and an antiepileptic drug carbamazepine, was determined at four municipal wastewater treatment plants (WWTPs) and in the receiving waterway near the city of Jyväskylä, in central Finland and also in the River Vantaa. First, an analytical method was developed including a pretreatment and purification followed by liquid chromatography coupled to tandem mass spectrometry (LC-...

  4. Polychlorinated Biphenyls in the Centralized Wastewater Treatment Plant in a Chemical Industry Zone: Source, Distribution, and Removal

    OpenAIRE

    Min Yao; Zhongjian Li; Xingwang Zhang; Lecheng Lei

    2014-01-01

    Polychlorinated biphenyls (PCBs) could be dissolved in wastewater or adsorbed on particulate. The fate of PCBs in wastewater is essential to evaluate the feasibility of wastewater treatment processes and the environmental risk. Here dissolved and adsorbed concentrations of twenty concerned PCB congeners and total PCBs have been measured in the centralized wastewater treatment plant of a chemical industry zone in Zhejiang, China. It was found that the dyeing chemical processes were the main so...

  5. Resolution of the direct containment heating issue for all Westinghouse plants with large dry containments or subatmospheric containments

    Energy Technology Data Exchange (ETDEWEB)

    Pilch, M.M.; Allen, M.D.; Klamerus, E.W. [Sandia National Labs., Albuquerque, NM (United States)

    1996-03-01

    This report uses the methodology and scenarios described in NUREG/CR-6075 and NUREG/CR-6075, Supplement 1, to address the direct containment heating (DCH) issue for all Westinghouse plants with large dry or subatmospheric containments. DCH is considered resolved if the conditional containment failure probability (CCFP) is less than 0.1. The methodology calls for an initial screening phase in which the CCFP for each plant is calculated based on loads versus strength evaluations using plant-specific information. The DCH issue is considered resolved for a plant if the CCFP calculated in the screening phase is less than 0.01. This value is more stringent than the overall success criterion of 0.1. The CCFPs for all of the Westinghouse plants with dry containments were less than 0.01 in the screening phase calculations, and thus, the DCH issue is resolved for these plants based on containment loads alone. No additional analyses are required.

  6. Urban heat island impacts on plant phenology: intra-urban variability and response to land cover

    Science.gov (United States)

    Zipper, Samuel C.; Schatz, Jason; Singh, Aditya; Kucharik, Christopher J.; Townsend, Philip A.; Loheide, Steven P., II

    2016-05-01

    Despite documented intra-urban heterogeneity in the urban heat island (UHI) effect, little is known about spatial or temporal variability in plant response to the UHI. Using an automated temperature sensor network in conjunction with Landsat-derived remotely sensed estimates of start/end of the growing season, we investigate the impacts of the UHI on plant phenology in the city of Madison WI (USA) for the 2012-2014 growing seasons. Median urban growing season length (GSL) estimated from temperature sensors is ˜5 d longer than surrounding rural areas, and UHI impacts on GSL are relatively consistent from year-to-year. Parks within urban areas experience a subdued expression of GSL lengthening resulting from interactions between the UHI and a park cool island effect. Across all growing seasons, impervious cover in the area surrounding each temperature sensor explains >50% of observed variability in phenology. Comparisons between long-term estimates of annual mean phenological timing, derived from remote sensing, and temperature-based estimates of individual growing seasons show no relationship at the individual sensor level. The magnitude of disagreement between temperature-based and remotely sensed phenology is a function of impervious and grass cover surrounding the sensor, suggesting that realized GSL is controlled by both local land cover and micrometeorological conditions.

  7. Elecnuc. Nuclear power plants in the world; Elecnuc. Les centrales nucleaires dans le monde

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    This small booklet summarizes in tables all data relative to the nuclear power plants worldwide. These data come from the IAEA's PRIS and AREVA-CEA's GAIA databases. The following aspects are reviewed: 2007 highlights; Main characteristics of reactor types; Map of the French nuclear power plants on 2007/01/01; Worldwide status of nuclear power plants (12/31/2007); Units distributed by countries; Nuclear power plants connected to the Grid- by reactor type groups; Nuclear power plants under construction on 2007; Evolution of nuclear power plants capacities connected to the grid; First electric generations supplied by a nuclear unit in each country; Electrical generation from nuclear power plants by country at the end 2007; Performance indicator of French PWR units; Evolution of the generation indicators worldwide by type; Nuclear operator ranking according to their installed capacity; Units connected to the grid by countries at 12/31/2007; Status of licence renewal applications in USA; Nuclear power plants under construction at 12/31/2007; Shutdown reactors; Exported nuclear capacity in net MWe; Exported and national nuclear capacity connected to the grid; Exported nuclear power plants under construction; Exported and national nuclear capacity under construction; Nuclear power plants ordered at 12/31/2007; Long term shutdown units at 12/31/2007; COL (combined licences) applications in the USA; Recycling of Plutonium in reactors and experiences; Mox licence plants projects; Appendix - historical development; Meaning of the used acronyms; Glossary.

  8. Operation Strategies of Heat Accumulator in Combined Heat and Power Plant with Uncertain Wind Power%考虑风电不确定性的热电厂蓄热罐运行策略

    Institute of Scientific and Technical Information of China (English)

    吕泉; 王海霞; 陈天佑; 李纯; 朱全胜; 李卫东

    2015-01-01

    By installing the heat accumulator,a combined heat and power (CHP) plant is able to effectively reduce its power output in valley load hours of heating period for accommodating curtailed wind power.But the operation strategy of the heat accumulator should be made by centralized dispatching in China at present so that the potential of accommodating wind power by heat accumulator can be brought into full play.In order to take the uncertainty of wind power into account,a CHP dispatch model based on scenario analysis is built to get the operation strategy of heat accumulator.Further,a simpler but practical method is designed as a substitute of the model.The numerical examples have verified the effectiveness of the two methods, showing that the operation strategies of heat accumulator obtained by two methods are almost the same.So the practical method can well be used to replace the multi-scenarios model to get the optimal operation strategy of the heat accumulator.%热电厂配置蓄热罐可有效提高其供暖期负荷低谷时段的下调峰能力来消纳弃风电力,但在国内需要通过集中调度确定充放热运行策略以充分发挥其调峰潜力。为考虑风电不确定性,建立了基于多场景的含储热的电热综合调度模型来优化确定蓄热罐运行策略;进一步为减少计算复杂性,提出一种简化的实用化确定方法。算例验证了两个模型的有效性,并且表明两者所确定的蓄热罐运行方式差异很小,因此实用化确定方法完全可替代基于多场景的电热综合调度模型。

  9. Mirror Advanced Reactor Study (MARS). Final report. Volume 1-B. Commercial fusion electric plant

    Energy Technology Data Exchange (ETDEWEB)

    Donohue, M.L.; Price, M.E. (eds.)

    1984-07-01

    Volume 1-B contains the following chapters: (1) blanket and reflector; (2) central cell shield; (3) central cell structure; (4) heat transport and energy conversion; (5) tritium systems; (6) cryogenics; (7) maintenance; (8) safety; (9) radioactivity, activation, and waste disposal; (10) instrumentation and control; (11) balance of plant; (12) plant startup and operation; (13) plant availability; (14) plant construction; and (15) economic analysis.

  10. Mirror Advanced Reactor Study (MARS). Final report. Volume 1-B. Commercial fusion electric plant

    International Nuclear Information System (INIS)

    Volume 1-B contains the following chapters: (1) blanket and reflector; (2) central cell shield; (3) central cell structure; (4) heat transport and energy conversion; (5) tritium systems; (6) cryogenics; (7) maintenance; (8) safety; (9) radioactivity, activation, and waste disposal; (10) instrumentation and control; (11) balance of plant; (12) plant startup and operation; (13) plant availability; (14) plant construction; and (15) economic analysis

  11. Modeling Potential Impacts of Planting Palms or Tree in Small Holder Fruit Plantations on Ecohydrological Processes in the Central Amazon

    Directory of Open Access Journals (Sweden)

    Norbert Kunert

    2015-07-01

    Full Text Available Native fruiting plants are widely cultivated in the Amazon, but little information on their water use characteristics can be found in the literature. To explore the potential impacts of plantations on local to regional water balance, we studied plant water use characteristics of two native fruit plants commonly occurring in the Amazon region. The study was conducted in a mixed fruit plantation containing a dicot tree species (Cupuaçu, Theobroma grandiflorum and a monocot palm species (Açai, Euterpe oleracea close to the city of Manaus, in the Central Amazon. Scaling from sap flux measurements, palms had a 3.5-fold higher water consumption compared to trees with a similar diameter. Despite the high transpiration rates of the palms, our plantation had only one third of the potential water recycling capacity of natural forests in the area. Converting natural forest into such plantations will thus result in significantly higher runoff rates.

  12. 中央热送风冲天炉的应用%Application of Central Blast-heating Cupola

    Institute of Scientific and Technical Information of China (English)

    冯英宇; 苏文生

    2011-01-01

    为提高冲天炉的综合性能,通过采取中央集中送风,合理控制风口风速,合理的炉膛结构,防止风嘴熔化等措施.强化焦炭燃烧,增加了焦炭的燃烧比,提高了冲天炉熔炼铁液的出炉温度;能适用混合焦炭,简化了焦炭处理;使炉衬侵蚀减小,修炉简便.通过多年实践改进,完善了中央送风冲天炉的相关工艺参数.该炉型操作简单,有利于降低硅、锰烧损和节能,打炉方便,生产稳定,可在同行业推广.%To improve the overall performance of cupola, taking the measures of centralized air supply, reasonable air control speed, reasonable furnace structurc and preventing the tuyere from mclting, the process of coke combustion is enhanced, the combustion ratio of coke increases and the tapping temperature of cupola melting iron improves. Mixed coke can be applied under the above measures, so the coke processing is simplified, which reduces lining erosion, makes repairing furnace simple. Through practicing and improving in years, the relevant process parameters of central blast-heating cupola are perfected. The cupola is simple in work and stable in production, which can reduce silicon-manganese melting loss and save energy. The cupola is worth of spreading in the same industry.

  13. Are plant N-alkylamide cosmenutriceuticals also active in the central nervous system?

    OpenAIRE

    Veryser, Lieselotte; Wynendaele, Evelien; Taevernier, Lien; Verbeke, Frederick; Joshi, Tanmayee; Tatke, Pratima; De Spiegeleer, Bart

    2014-01-01

    Background: The biomedical interest in N-alkylamides (NAAs), a large group of secondary metabolites found in various medicinal plants, has increased enormously. These compounds, occurring in more than 25 plant families, have a wide structural diversity and are potential lead compounds for functional food, cosmetics and pharmaceutical drugs, as well as biocidal and plant protection products. They are known to have analgesic, antimicrobial, insecticidal, sensory, anti-inflammatory and immune-mo...

  14. Feasibility of geothermal heat use in the San Bernardino Municipal Wastewater Treatment Plant. Final report, September 1980-June 1981

    Energy Technology Data Exchange (ETDEWEB)

    Racine, W.C.; Larson, T.C.; Stewart, C.A.; Wessel, H.B.

    1981-06-01

    The results of the feasibility study for utilizing low temperature geothermal heat in the City of San Bernardino Wastewater Treatment Plant are summarized. The study is presented in terms of preliminary engineering design, economic analysis, institutional issues, environmental impacts, resource development, and system implementation.

  15. Impact of soil heat on reassembly of bacterial communities in the rhizosphere microbiome and plant disease suppression

    NARCIS (Netherlands)

    Voort, van der M.; Kempenaar, Marcel; Driel, van Marc; Raaijmakers, Jos M.; Mendes, Rodrigo

    2016-01-01

    The rhizosphere microbiome offers a range of ecosystem services to the plant, including nutrient acquisition and tolerance to (a)biotic stress. Here, analysing the data by Mendes et al. (2011), we show that short heat disturbances (50 or 80 °C, 1 h) of a soil suppressive to the root pathogenic fu

  16. Program of low emissions elimination and power recovery by the Krakow heat and power plant for the city of Krakow and its residents

    Energy Technology Data Exchange (ETDEWEB)

    Drezewski, J.; Kasprzyk, T. [Krakow Heat and Power Plant, Cracow (Poland)

    1995-12-31

    For over three years the Krakow Heat and Power Plant S.A. (ECK SA) has been implementing its strategy of adapting to operation and growth in the market economy. The accomplishment and results of these efforts are presented. The social and economic conditions prevailing during the transformation from a centrally controlled economy to a market economy have changed the realities and regulations that restricted the availability of energy carriers. The continual shortages and restrictions on supplies of gas, electricity, heat and even solids fuels (coke) that occurred in previous years have been replaced by a surplus. That is why many investment planning decisions have had to be revised. A sharp increase in energy carrier prices has required detailed analyses and viability studies to be made before final investment decisions are made. The choice of fuel and heating methods has begun to be dictated by the market and the economy, and not by rationing and administrative decisions. Clearly, a free market in energy generation and distribution has come into existence in the Krakow urban area. In general, these trends will produce a situation in which the fixed cost (depreciation, repairs, payroll) incurred by manufacturers and distributors will be apportioned among a smaller number of power units (MW), thus increasing the capacity price (fixed payment).

  17. Power plant heating system integrating low temperature heat and absorption heat pumps%电厂低温热与吸收式热泵耦合供热系统研究

    Institute of Scientific and Technical Information of China (English)

    邱丽霞; 郝艳红

    2015-01-01

    On the basis of analysis on two kinds of waste heat utilization approaches,using the low-tempera-ture flue gas waste heat to heat the condensate water and feed water by installing heat exchangers in the tail flue duct,and improving the quality of steam turbine exhaust and circulating water to supply heat for users by adopting absorption heat pumps,a novel waste heat utilization system for thermal power plants was proposed.In this system,the flue gas after the air preheater is regarded as the heat pump's driving heat source,thus the absorption heat pump can recover the heat of condensation and heat the heating hot water. In addition,in order to meet the heating requirements in extremely cold periods,the heat exchanger is in-stalled after the economizer in the tail flue duct,in which the heating hot water from heat pump exit is heated by part of the flue gas extracted from outlet of the economizer.In this system,the low-temperature heat is recovered by the absorption heat pump,so that the exergy loss is reduced in the heat transfer process,the extraction steam from the steam turbine decreases and the output power increases.Further-more,combined with a 330 MW heat supply unit,this novel system's energy-saving effect was analyzed and the results were compared with that of the conventional flue gas waste heat utilization system (convention-al system I)and the conventional condensation heat heat pump system (conventional system2).The results show that,the annual standard coal consumption of the unit applying this novel system is 8 487.8 t less than that applying the conventional system I,and the output power is 1.3% to 2.7% higher than that ap-plying the conventional system II,which indicates the energy saving effect of this novel waste heat utiliza-tion system is remarkable.%基于常规烟气余热利用系统(常规系统1)及常规冷凝热热泵系统(常规系统2),提出了一种新型的电厂余热利用系统:将空气预热器(空预器)后的烟气作为

  18. Influence of heat consumers distribution and flashing vapours effect on steam consumption of evaporation plant of sugar factory

    Directory of Open Access Journals (Sweden)

    A. A. Gromkovskii

    2016-01-01

    Full Text Available The article considered the influence of the heat consumers distribution and the flashing vapours effect juice for multipleevaporator sugar factory on the consumption the main production flow of heat transfer agent – water vapor. The problem of rational distribution of heat transfer agent for of the corps multiple-evaporator is relevant from point of view of energy saving and energysaving heat of the sugar factory. The solution to this problem is advantageously carried out on the basis of quantitative mathematical description of the distribution of vapor on the corps of the evaporation plant. The heat consumers distribution should be based on technical and economic calculation. To solve this problem it is advisable to use a single equation that determines the dependence of the steam flow in the first unit evaporator on the amount of evaporated water and the method of heat consumers distribution for housing. Evaporators sugar factory has two functions – technology and heat, each of which is described by its equation. On the basis of the material and heat balance equations for the realization of the basic functions of the system evaporator written multipleevaporator equations. The solution of this system allows you to obtain the equation of the steam flow and the amount of evaporated water, taking into account the flashing vapours effect. Solution of the system should take into account the accepted design standards of sugar factories. As a result of solving the system of equation is obtained, which allows you to organize and optimize the heat consumers distribution of the corps evaporator. The equation can be used for any number of units evaporator. This equation allows you to assess the efficiency of the evaporation plant of a sugar factory. This is of great practical importance in the modernization of thermal schemes of sugar factories.

  19. Analysis of Heat Balance on Innovative-Simplified Nuclear Power Plant Using Multi-Stage Steam Injectors

    Science.gov (United States)

    Goto, Shoji; Ohmori, Shuichi; Mori, Michitsugu

    The total space and weight of the feedwater heaters in a nuclear power plant (NPP) can be reduced by replacing low-pressure feedwater heaters with high-efficiency steam injectors (SIs). The SI works as a direct heat exchanger between feedwater from condensers and steam extracted from turbines. It can attain pressures higher than the supplied steam pressure. The maintenance cost is lower than that of the current feedwater heater because of its simplified system without movable parts. In this paper, we explain the observed mechanisms of the SI experimentally and the analysis of the computational fluid dynamics (CFD). We then describe mainly the analysis of the heat balance and plant efficiency of the innovative-simplified NPP, which adapted to the boiling water reactor (BWR) with the high-efficiency SI. The plant efficiencies of this innovative-simplified BWR with SI are compared with those of a 1100MWe-class BWR. The SI model is adopted in the heat balance simulator as a simplified model. The results show that the plant efficiencies of the innovate-simplified BWR with SI are almost equal to those of the original BWR. They show that the plant efficiency would be slightly higher if the low-pressure steam, which is extracted from the low-pressure turbine, is used because the first-stage of the SI uses very low pressure.

  20. Modeling the high-temperature gas-cooled reactor process heat plant: a nuclear to chemical conversion process

    International Nuclear Information System (INIS)

    The high-temperature heat available from the High-Temperature Gas-Cooled Reactor (HTGR) makes it suitable for many process applications. One of these applications is a large-scale energy production plant where nuclear energy is converted into chemical energy and stored for industrial or utility applications. This concept combines presently available nuclear HTGR technology and energy conversion chemical technology. The design of this complex plant involves questions of interacting plant dynamics and overall plant control. This paper discusses how these questions were answered with the aid of a hybrid computer model that was developed within the time-frame of the conceptual design studies. A brief discussion is given of the generally good operability shown for the plant and of the specific potential problems and their anticipated solution. The paper stresses the advantages of providing this information in the earliest conceptual phases of the design

  1. Heat tracing to examine seasonal groundwater flow beneath a low-gradient stream in rural central Illinois, USA

    Science.gov (United States)

    Bastola, Hridaya; Peterson, Eric W.

    2016-02-01

    The thermal profile of a streambed is affected by a number of factors including: temperatures of stream water and groundwater, hydraulic conductivity, thermal conductivity, heat capacity of the streambed, and the geometry of hyporheic flow paths. Changes in these parameters over time cause changes in thermal profiles. In this study, temperature data were collected at depths of 30, 60, 90 and 150 cm at six streambed wells 5 m apart along the thalweg of Little Kickapoo Creek, in rural central Illinois, USA. This is a third-order low-gradient baseflow-fed stream. A positive temperature gradient with inflection at 90-cm depth was observed during the summer period. A negative temperature gradient with inflection at 30 cm was observed during the winter period, which suggests greater influence of stream-water temperatures in the substrate during the summer. Thermal models of the streambed were built using VS2DHI to simulate the thermal profiles observed in the field. Comparison of the parameters along with analysis of temperature envelopes and Peclet numbers suggested greater upwelling and stability in temperatures during the winter than during the summer. Upwelling was more pronounced in the downstream reach of the pool in the riffle and pool sequence.

  2. Antimicrobial Activity of Some Medicinal Plants from East and Central Part of Nepal

    OpenAIRE

    Bimala Subba*; Prakash Basnet

    2014-01-01

    To evaluate the antimicrobial activities of extract of eleven plants were examined against four common bacterials. The ethanolic extracts of various plants such as Cissus repens, Hedyotis scandens, Jatropha curcas, Morus alba, Inula cappa, Equisetum ramosissimum, Osyris wightiana, Alternantheria sessilis and Hibiscus lampas investigated individually for antimicrobial activity by disc diffusion method. These were investigated against selected species of Staphylococcus aureus, Escherichia col...

  3. Altitudinal Pattern of Plant Species Diversity in Shennongjia Mountains, Central China

    Institute of Scientific and Technical Information of China (English)

    Chang-Ming ZHAO; Wei-Lie CHEN; Zi-Qiang TIAN; Zong-Qiang XIE

    2005-01-01

    One hundred and sixty plots, approximately every 100 m above sea level (a.s.l.) along an altitudinal gradient from 470 to 3 080 m a.s.l, at the southern and northern watershed of Mt. Shennongjia,China, were examined to determine the altitudinal pattern of plant species diversity. Mt. Shennongjia was found to have high plant species diversity, with 3 479 higher plants recorded. Partial correlation analysis and detrended canonical correspondence analysis (DCCA) based on plant species diversity revealed that altitude was the main factor affecting the spatial pattern of plant species diversity on Mt. Shennongjia and that canopy coverage of the arbor layer also had a considerable effect on plant species diversity. The DCCA based on species data of importance value further revealed that altitude gradient was the primary factor shaping the spatial pattern of plant species. In addition, the rule of the "mid-altitude bulge" was supported on Mt. Shennongjia. Plant species diversity was closely related to vegetation type and the transition zone usually had a higher diversity. Higher plant species diversity appeared in the mixed evergreen and deciduous broadleaved forest zone (900-1 500 m a.s.l.) and its transition down to evergreen broadleaved forest zone or up to deciduous broadleaved forest zone. The largest plant species diversity in whole communities on Mt. Shennongjia lay at approximately 1 200 m a.s.l. Greatest tree diversity, shrub diversity, and grass diversity was found at approximately 1 500, 1 100, and 1 200 m a.s.l., respectively. The southern watershed showed higher plant species diversity than the northern watershed, with maximum plant species diversity at a higher altitude in the southern watershed than the northern watershed. These results indicate that Mt.Shennongjia shows characteristics of a transition region. The relationship between the altitudinal pattern of plant species diversity and the vegetation type in eastern China are also discussed and a

  4. Regional Climate Zone Modeling of a Commercial Absorption Heat Pump Hot Water Heater Part 1: Southern and South Central Climate Zones

    Energy Technology Data Exchange (ETDEWEB)

    Geoghegan, Patrick J [ORNL; Shen, Bo [ORNL; Keinath, Christopher M. [Stone Mountain Technologies, Inc., Johnson City; Garrabrant, Michael A. [Stone Mountain Technologies, Inc., Johnson City

    2016-01-01

    Commercial hot water heating accounts for approximately 0.78 Quads of primary energy use with 0.44 Quads of this amount from natural gas fired heaters. An ammonia-water based commercial absorption system, if fully deployed, could achieve a high level of savings, much higher than would be possible by conversion to the high efficiency nonheat-pump gas fired alternatives. In comparison with air source electric heat pumps, the absorption system is able to maintain higher coefficients of performance in colder climates. The ammonia-water system also has the advantage of zero Ozone Depletion Potential and low Global Warming Potential. A thermodynamic model of a single effect ammonia-water absorption system for commercial space and water heating was developed, and its performance was investigated for a range of ambient and return water temperatures. This allowed for the development of a performance map which was then used in a building energy modeling software. Modeling of two commercial water heating systems was performed; one using an absorption heat pump and another using a condensing gas storage system. The energy and financial savings were investigated for a range of locations and climate zones in the southern and south central United States. A follow up paper will analyze northern and north/central regions. Results showed that the system using an absorption heat pump offers significant savings.

  5. In-situ calibration of large heat meters in district heating plants by means of radioisotope flow measuring methods

    International Nuclear Information System (INIS)

    The growing use of district heating network requires a reliable system of calibrated heat meters. Radioactive tracer techniques enable such control and calibration. The standardized methods of liquid flow measuring by means of radioisotope injection are described in ISO Standards 2975/VII and 555/3. The measurement consists in isotope dilution determination in hot water samples, rather than in determination of the flow rate which requires a long distance between the injection and testing point on the heat distribution pipeline. The development project aims at modification and construction of specialized equipment for radioisotopic calibration measurements of large heat meters according to the flow-rate method and dilution method. Testing of the method efficiency is based on comparison with reference measurements of the Danish Technological Institute. Instrumentation is described in detail in the Appendix. All the stages from tracer dosing for injections to the determination of the tracer in the final extracted sample are automatically controlled by a PC software, not included in this report. (EG)

  6. Water as carrier of information of heat shock and drug effect between two groups of Adhatoda vasica plants

    Directory of Open Access Journals (Sweden)

    N C Sukul

    2012-06-01

    Full Text Available Adhatoda vasica Nees plants were grown in 50 earthen pots, which were divided into 5 batches A, B, C, D, and E. Of these A, B and C, D were arranged into two separate parallel pairs. One leaf of each plant of an adjacent pair was immersed in sterile tap water in a beaker. Adjacent beakers in each pair A B or C D were connected by polythene tubes containing wet cotton threads. One leaf of each plant of A was given heat shock by immersing a leaf in hot water for 5 min. One leaf of each plant of C was treated with Cantharis vesicatoria 200c. Batch E served as the unstressed and untreated control. One hour after heat shock or drug treatment all the leaves were harvested and their proteins were extracted by chilled protein extraction buffer. Proteins were separated by Fast Protein Liquid Chromatography (FPLC. Protein profiles of A, B and C, D showed marked similarity with respect to expression and repression of some proteins. It is concluded that the effect of heat shock and drug treatment is transmitted through water in the capillaries of cotton threads connecting the pairs of plants. It is assumed that heat shock or drug treatment altered locally the water structure in the leaves which was propagated through global network of water structure over the protein network in the whole plants, and from there to the interfacial water in the beakers and cotton threads. A homeopathic potency is thought to be specifically structured water which influences the water structure in the treated organism.

  7. Heating, ventilating, and air conditioning deactivation thermal analysis of PUREX Plant

    Energy Technology Data Exchange (ETDEWEB)

    Chen, W.W.; Gregonis, R.A. [Westinghouse Hanford Company, Richland, WA (United States)

    1997-08-01

    Thermal analysis was performed for the proposed Plutonium Uranium Extraction Plant exhaust system after deactivation. The purpose of the analysis was to determine if enough condensation will occur to plug or damage the filtration components. A heat transfer and fluid flow analysis was performed to evaluate the thermal characteristics of the underground duct system, the deep-bed glass fiber filter No. 2, and the high-efficiency particulate air filters in the fourth filter building. The analysis is based on extreme variations of air temperature, relative humidity, and dew point temperature using 15 years of Hanford Site weather data as a basis. The results will be used to evaluate the need for the electric heaters proposed for the canyon exhaust to prevent condensation. Results of the analysis indicate that a condition may exist in the underground ductwork where the duct temperature can lead or lag changes in the ambient air temperature. This condition may contribute to condensation on the inside surfaces of the underground exhaust duct. A worst case conservative analysis was performed assuming that all of the water is removed from the moist air over the inside surface of the concrete duct area in the fully developed turbulent boundary layer while the moist air in the free stream will not condense. The total moisture accumulated in 24 hours is negligible. Water puddling would not be expected. The results of the analyses agree with plant operating experiences. The filters were designed to resist high humidity and direct wetting, filter plugging caused by slight condensation in the upstream duct is not a concern. 19 refs., 2 figs.

  8. Possible role of growth regulators in adaptation to heat stress affecting partitioning of photosynthates in tomato plants

    Directory of Open Access Journals (Sweden)

    Zofia Starck

    2014-02-01

    Full Text Available Tomato plants of two cultivars: Roma - sensitive and Robin - tolerant to heat stress were grown in greenhouse up to the flowering stage and then under controlled environmen­tal conditions. The partitioning of recently fixed 14CO2 by mature tomato leaves was examined as a posteffect of 24-h heat stress (38/25°C day/night with the interaction of growth regulators (GR sprayed on the flowers with solution of β-naphthoxyacetic (NOA and gibberellic (GA3 acid (denoted as NG, or Zeatin + NOA + GA3 (denoted as ZNG. In both cuitivars GR strongly stimulated fruit growth and transport of 14C-photosynthates to the clusters at the expense of vegetative organs. Heat stress decreased export of 14C-phoiosynthates from the blades in plants not treated with GR, but even more in cv. Roma. In Roma plants not treated with GR (with very small fruitlets and fruits the heat stress retarded 14C-transport just in the petioles, diminishing the 14C-supply to the fruits. Reduction of the current photosynthate supplied to the fruits seems to be causally connected with inhibition of the specific activity of acid invertase in that organ. Growth regulators reduced the negative effect of high temperature - they alleviated depression of 14C-export from the blades and increased invertase activity. 14C-photosynthate transport to the fruits, presumably owing to their higher sink strength, was less affected by heat stress. In Robin plants (which had bigger fruits during the experiment high temperature depressed 14C-fruit supply only in the NG-series, in contrast to enhacement of 14C-Movement to that sink in the control and ZNG-series. In spite of these facts, after heat stress, the specific activity of acid invertase decreased in all the experimental series, but much less in the GR-treated series. Therefore, in the Robin cv. there was no relation between invertase activity and 14C-mobilization by fruits, as was observed in Roma plants. The possible explanation of the different

  9. Elecnuc. Nuclear power plants in the world; Elecnuc. Les centrales nucleaires dans le monde

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    This small booklet summarizes in tables all the numerical data relative to the nuclear power plants worldwide. These data come from the French CEA/DSE/SEE Elecnuc database. The following aspects are reviewed: 1999 highlights; main characteristics of the reactor types in operation, under construction or on order; map of the French nuclear power plants; worldwide status of nuclear power plants at the end of 1999; nuclear power plants in operation, under construction and on order; capacity of nuclear power plants in operation; net and gross capacity of nuclear power plants on the grid and in commercial operation; grid connection forecasts; world electric power market; electronuclear owners and share holders in EU, capacity and load factor; first power generation of nuclear origin per country, achieved or expected; performance indicator of PWR units in France; worldwide trend of the power generation indicator; 1999 gross load factor by operator; nuclear power plants in operation, under construction, on order, planned, cancelled, shutdown, and exported; planning of steam generators replacement; MOX fuel program for plutonium recycling. (J.S.)

  10. Agroforestry leads to shifts within the gammaproteobacterial microbiome of banana plants cultivated in Central America.

    Science.gov (United States)

    Köberl, Martina; Dita, Miguel; Martinuz, Alfonso; Staver, Charles; Berg, Gabriele

    2015-01-01

    Bananas (Musa spp.) belong to the most important global food commodities, and their cultivation represents the world's largest monoculture. Although the plant-associated microbiome has substantial influence on plant growth and health, there is a lack of knowledge of the banana microbiome and its influencing factors. We studied the impact of (i) biogeography, and (ii) agroforestry on the banana-associated gammaproteobacterial microbiome analyzing plants grown in smallholder farms in Nicaragua and Costa Rica. Profiles of 16S rRNA genes revealed high abundances of Pseudomonadales, Enterobacteriales, Xanthomonadales, and Legionellales. An extraordinary high diversity of the gammaproteobacterial microbiota was observed within the endophytic microenvironments (endorhiza and pseudostem), which was similar in both countries. Enterobacteria were identified as dominant group of above-ground plant parts (pseudostem and leaves). Neither biogeography nor agroforestry showed a statistically significant impact on the gammaproteobacterial banana microbiome in general. However, indicator species for each microenvironment and country, as well as for plants grown in Coffea intercropping systems with and without agri-silvicultural production of different Fabaceae trees (Inga spp. in Nicaragua and Erythrina poeppigiana in Costa Rica) could be identified. For example, banana plants grown in agroforestry systems were characterized by an increase of potential plant-beneficial bacteria, like Pseudomonas and Stenotrophomonas, and on the other side by a decrease of Erwinia. Hence, this study could show that as a result of legume-based agroforestry the indigenous banana-associated gammaproteobacterial community noticeably shifted.

  11. Agroforestry leads to shifts within the gammaproteobacterial microbiome of banana plants cultivated in Central America

    Directory of Open Access Journals (Sweden)

    Martina eKöberl

    2015-02-01

    Full Text Available Bananas (Musa spp. belong to the most important global food commodities, and their cultivation represents the world’s largest monoculture. Although the plant-associated microbiome has substantial influence on plant growth and health, there is a lack of knowledge of the banana microbiome and its influencing factors. We studied the impact of i biogeography, and ii agroforestry on the banana-associated gammaproteobacterial microbiome analyzing plants grown in smallholder farms in Nicaragua and Costa Rica. Profiles of 16S rRNA genes revealed high abundances of Pseudomonadales, Enterobacteriales, Xanthomonadales, and Legionellales. An extraordinary high diversity of the gammaproteobacterial microbiota was observed within the endophytic microenvironments (endorhiza and pseudostem, which was similar in both countries. Enterobacteria were identified as dominant group of above-ground plant parts (pseudostem and leaves. Neither biogeography nor agroforestry showed a statistically significant impact on the gammaproteobacterial banana microbiome in general. However, indicator species for each microenvironment and country, as well as for plants grown in Coffea intercropping systems with and without agri-silvicultural production of different Fabaceae trees (Inga spp. in Nicaragua and Erythrina poeppigiana in Costa Rica could be identified. For example, banana plants grown in agroforestry systems were characterized by an increase of potential plant-beneficial bacteria, like Pseudomonas and Stenotrophomonas, and on the other side by a decrease of Erwinia. Hence, this study could show that as a result of legume-based agroforestry the indigenous banana-associated gammaproteobacterial community noticeably shifted.

  12. Does plant immunity have a central role in the legume rhizobium symbiosis?

    Directory of Open Access Journals (Sweden)

    Katalin eToth

    2015-06-01

    Full Text Available Plants are exposed to many different microbes in their habitat. These microbes may be benign or pathogenic, but in some cases they are beneficial. The rhizosphere provides an especially rich palette for colonization by beneficial (associative and symbiotic microorganisms, which raises the question as to how roots can distinguish such ‘friends’ from possible ‘foes’ (i.e., pathogens. Plants possess an innate immunity system that can recognize pathogens, through an arsenal of protein receptors. These receptors include receptor-like kinases (RLK and receptor-like proteins (RLP located at the plasma membrane, as well as intracellular receptors (so called NBS-LRR proteins or R proteins that recognize molecules released by microbes into the plant cell. The key rhizobial, symbiotic signaling molecule (called Nod factor is perceived by the host legume plant using LysM-domain containing RLKs. Perception of the symbiotic Nod factor triggers signaling cascades leading to bacterial infection and accommodation of the symbiont in a newly formed root organ, the nodule, resulting in a nitrogen-fixing root nodule symbiosis (RNS. The net result of this symbiosis is the intracellular colonization of the plant with thousands of bacteria; a process that seems to occur in spite of the immune ability of plants to prevent pathogen infection. In this review, we discuss the potential of the invading rhizobial symbiont to actively avoid this innate immunity response, as well as specific examples of where the plant immune response may modulate rhizobial infection and host range.

  13. Central heating: package boilers

    Energy Technology Data Exchange (ETDEWEB)

    Farahan, E.

    1977-05-01

    Performance and cost data for electrical and fossil-fired package boilers currently available from manufacturers are provided. Performance characteristics investigated include: unit efficiency, rated capacity, and average expected lifetime of units. Costs are tabulated for equipment and installation of various package boilers. The information supplied in this report will simplify the process of selecting package boilers required for industrial, commercial, and residential applications.

  14. A study of a solar central power plant with a gas turbine - Project Sirocco modelling and control

    Science.gov (United States)

    Kacim, M.

    A thermodynamics and receiver design analysis is presented for a solar tower power plant, together with a control model for operations in varying working conditions. The analysis covers the central receiver and the gas-air turbine, adapted for functioning at 820 C, such as was experienced with the 100 kW Project Sirocco test station. A heliostat field concentrates solar energy onto a central receiver traversed by compressed air, which is allowed to expand while driving a turbine generator. A combustion chamber is included in the loop to augment the thermal performance when insufficient solar energy is available. The plant can be either grid-connected or stand alone. Static and dynamic characteristics of the thermal loop are modelled, and are included in the development of control laws based on quadratic criteria. An optimized control scheme is devised which features weighting criteria matrices, and the results of simulations covering different insolation levels are reported. Finally, an adjoint state control system is produced to account for peculiarities of the power plant.

  15. Vascular plants of the Nevada Test Site and Central-Southern Nevada: ecologic and geographic distributions

    Energy Technology Data Exchange (ETDEWEB)

    Beatley, J.C.

    1976-01-01

    The physical environment of the Nevada Test Site and surrounding area is described with regard to physiography, geology, soils, and climate. A discussion of plant associations is given for the Mojave Desert, Transition Desert, and Great Basin Desert. The vegetation of disturbed sites is discussed with regard to introduced species as well as endangered and threatened species. Collections of vascular plants were made during 1959 to 1975. The plants, belonging to 1093 taxa and 98 families are listed together with information concerning ecologic and geographic distributions. Indexes to families, genera, and species are included. (HLW)

  16. Preliminary design of the Carrisa Plains solar central receiver power plant. Volume III, Book 3. Appendices, Part 1

    Energy Technology Data Exchange (ETDEWEB)

    Mouradian, E. M.

    1983-12-31

    Thermal analyses for the preliminary design phase of the Receiver of the Carrizo Plains Solar Power Plant are presented. The sodium reference operating conditions (T/sub in/ = 610/sup 0/F, T/sub out/ = 1050/sup 0/F) have been considered. Included are: Nominal flux distribution on receiver panal, Energy input to tubes, Axial temperature distribution; sodium and tubes, Sodium flow distribution, Sodium pressure drop, orifice calculations, Temperature distribution in tube cut (R-0), Backface structure, and Nonuniform sodium outlet temperature. Transient conditions and panel front face heat losses are not considered. These are to be addressed in a subsequent design phase. Also to be considered later are the design conditions as variations from the nominal reference (operating) condition. An addendum, designated Appendix C, has been included describing panel heat losses, panel temperature distribution, and tube-manifold joint thermal model.

  17. Performance and costs of advanced sustainable central power plants with CCS and H2 co-production

    International Nuclear Information System (INIS)

    Highlights: ► Thermo-economic analyses of co-producing electricity and H2 with CO2 capture. ► Gasification plants with solid oxide fuel cells and combined cycles are compared. ► 66 wt.% Utah coal, 17 wt.% corn stover and 17 wt.% cereal straw are gasified. ► H2 production cost is lowered by >50% with fuel cell based gasification plant. ► 70% more net electricity due to synergy between hydrogasification and fuel cells. -- Abstract: With increasing concerns over global climate change caused by GHG emissions, carbon capture and storage (CCS) has become imperative for coal based power plants. Meanwhile, with the development and deployment of hybrid vehicles, electric vehicles, and alternative fuel vehicles, GHG reduction efforts in the power industry can also benefit the transportation sector. Power plants with H2 co-production capability can contribute significantly in such development trends because H2 powered fuel cell hybrid vehicles are very promising for future “zero emissions vehicles”. This work investigates the thermodynamic performance and cost advantage of employing advanced technologies currently under development for central power plants that (1) employ coal and biomass as feed stock; (2) co-produce power and high purity H2; (3) capture most of the CO2 evolved within the plants. Two system designs are developed: the first “base” case is an integrated gasification combined cycle (IGCC) system consisting of commercially ready technologies; the second “advanced” case is an integrated gasification fuel cell (IGFC) system. The feedstock employed consists of Utah bituminous coal along with two typical biomass resources, corn stover and cereal straw. The IGFC plant produces significantly higher amount of electricity for the same amounts of feedstock and H2 export while the cost of producing the H2 using a cost of electricity of $135/MW h is $1178/tonne for the IGFC case versus $2620/tonne for the IGCC case.

  18. Dependable Hydrogen and Industrial Heat Generation from the Next Generation Nuclear Plant

    Energy Technology Data Exchange (ETDEWEB)

    Charles V. Park; Michael W. Patterson; Vincent C. Maio; Piyush Sabharwall

    2009-03-01

    The Department of Energy is working with industry to develop a next generation, high-temperature gas-cooled nuclear reactor (HTGR) as a part of the effort to supply the US with abundant, clean and secure energy. The Next Generation Nuclear Plant (NGNP) project, led by the Idaho National Laboratory, will demonstrate the ability of the HTGR to generate hydrogen, electricity, and high-quality process heat for a wide range of industrial applications. Substituting HTGR power for traditional fossil fuel resources reduces the cost and supply vulnerability of natural gas and oil, and reduces or eliminates greenhouse gas emissions. As authorized by the Energy Policy Act of 2005, industry leaders are developing designs for the construction of a commercial prototype producing up to 600 MWt of power by 2021. This paper describes a variety of critical applications that are appropriate for the HTGR with an emphasis placed on applications requiring a clean and reliable source of hydrogen. An overview of the NGNP project status and its significant technology development efforts are also presented.

  19. Co-combustion of Wood-Shavings and Horse Manure in a Small Scale Heating Plant

    Energy Technology Data Exchange (ETDEWEB)

    Pettersson, E. [Energy Technology Centre, Piteaa (Sweden); Lundgren, J.; Hermansson, R. [Luleaa Univ. of Technology (Sweden). Div. of Energy Engineering

    2006-07-15

    Due to the prohibition of disposal of organic material at landfills, there is a great interest amongst stable owners in finding practical, environmental and economic alternatives for handling of the horse manure. One option is to use the waste as fuel for local heat generation. A riding school, near the town of Timraa in the middle part of Sweden, has installed a boiler fired with a mixture of wood-shavings and horse manure. The main objectives with this study were to evaluate the environmental performance of the furnace and the total economy of the plant. The measurements showed that the emissions of CO were relatively low, typically below 200 mg/Nm{sup 3}. The NO{sub x} emissions were in the range of 360 mg/Nm{sup 3} to 450 mg/Nm{sup 3}, which is significantly higher than when firing conventional wood fuels. The reason is that this fuel contains up to nine times more nitrogen than for example wood-chips due to absorbed urine from the horses. The particle emissions were in the range of 390 mg/Nm{sup 3} to 470 mg/Nm{sup 3}. (All emission values are dry gas based and normalised to 10 volume % O{sub 2}). An economic evaluation comparing combustion, composting at a waste station and direct spread on arable land showed the lowest annual cost for combustion. This is an example of turning a cumbersome waste product into a profitable fuel.

  20. Response of four foliage plants to heated soil and reduced air temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Bodnaruk, W.H. Jr.; Mills, T.W.; Ingram, D.L.

    1981-01-01

    Tip cuttings of Dieffenbachia maculata (Lodd.) G. Donn Exotic Perfection Compacta' and Aglaonema commutatum Schott Silver Queen and single eye cuttings of Epipremnum aureum (Linden and Andre) Bunt, and Philodendron scandens oxycardium (Schott) Bunt. were propagated in combinations of 4 minimum air temperatures, 45/sup 0/, 50/sup 0/, 55/sup 0/ and 60/sup 0/F (7.2/sup 0/, 10/sup 0/, 12.7/sup 0/, 15.5/sup 0/C), and 2 soil temperature treatments; controlled 70/sup 0/F (21/sup 0/C) minimum and variable. Maintaining minimum soil temperatures at 70/sup 0/F reduced production times for rooted Dieffenbachia and Aglaonema tips by 45% and of Epipremnum and Philodendron suitable for 3 inch pots by 35% and 25%, respectively, regardless of minimum air temperature. Minimum air temperature had little effect on Dieffenbachia or Aglaonema root number and length at 70/sup 0/F soil temperature. Similarly shoot length and number of leaves of Philodendron and Epipremnum were not affected by minimum air temperatures with 70/sup 0/F soil temperature. Plant quality was uniformly high in all crops at the 70/sup 0/F soil minimum for all air temperatures except Epipremnum which was chlorotic at 45/sup 0/F. A description of a warm water in-benching heating system is included. 6 references, 2 figures, 9 tables.

  1. Placement of Combined Heat, Power and Hydrogen Production Fuel Cell Power Plants in a Distribution Network

    Directory of Open Access Journals (Sweden)

    Bahman Bahmanifirouzi

    2012-03-01

    Full Text Available This paper presents a new Fuzzy Adaptive Modified Particle Swarm Optimization algorithm (FAMPSO for the placement of Fuel Cell Power Plants (FCPPs in distribution systems. FCPPs, as Distributed Generation (DG units, can be considered as Combined sources of Heat, Power, and Hydrogen (CHPH. CHPH operation of FCPPs can improve overall system efficiency, as well as produce hydrogen which can be stored for the future use of FCPPs or can be sold for profit. The objective functions investigated are minimizing the operating costs of electrical energy generation of distribution substations and FCPPs, minimizing the voltage deviation and minimizing the total emission. In this regard, this paper just considers the placement of CHPH FCPPs while investment cost of devices is not considered. Considering the fact that the objectives are different, non-commensurable and nonlinear, it is difficult to solve the problem using conventional approaches that may optimize a single objective. Moreover, the placement of FCPPs in distribution systems is a mixed integer problem. Therefore, this paper uses the FAMPSO algorithm to overcome these problems. For solving the proposed multi-objective problem, this paper utilizes the Pareto Optimality idea to obtain a set of solution in the multi-objective problem instead of only one. Also, a fuzzy system is used to tune parameters of FAMPSO algorithm such as inertia weight. The efficacy of the proposed approach is validated on a 69-bus distribution system.

  2. Numerical modelling of distribution the discharged heat water from thermal power plant on the aquatic environment

    Science.gov (United States)

    Issakhov, Alibek

    2016-06-01

    The paper presents a mathematical model of distribution the discharged heat water from thermal power plant under various operational capacities on the aquatic environment. It was solved by the Navier-Stokes and temperature equations for an incompressible fluid in a stratified medium were based on the splitting method by physical parameters which approximated by the finite volume method. The numerical solution of the equation system was divided into four stages. At the first step it was assumed that the momentum transfer carried out only by convection and diffusion. While the intermediate velocity field was solved by 5-step Runge-Kutta method. At the second stage, the pressure field was solved by found the intermediate velocity field. Whereas Poisson equation for the pressure field was solved by Jacobi method. The third step assumes that the transfer was carried out only by pressure gradient. Finally the fourth step of the temperature equation was also solved as motion equations, with 5-step Runge-Kutta method. The algorithm was parallelized on high-performance computer. The obtained numerical results of three-dimensional stratified turbulent flow were compared with experimental data. What revealed qualitatively and quantitatively approximately the basic laws of hydrothermal processes occurring in the reservoir-cooler.

  3. Modeling a Printed Circuit Heat Exchanger with RELAP5-3D for the Next Generation Nuclear Plant

    Energy Technology Data Exchange (ETDEWEB)

    2010-12-01

    The main purpose of this report is to design a printed circuit heat exchanger (PCHE) for the Next Generation Nuclear Plant and carry out Loss of Coolant Accident (LOCA) simulation using RELAP5-3D. Helium was chosen as the coolant in the primary and secondary sides of the heat exchanger. The design of PCHE is critical for the LOCA simulations. For purposes of simplicity, a straight channel configuration was assumed. A parallel intermediate heat exchanger configuration was assumed for the RELAP5 model design. The RELAP5 modeling also required the semicircular channels in the heat exchanger to be mapped to rectangular channels. The initial RELAP5 run outputs steady state conditions which were then compared to the heat exchanger performance theory to ensure accurate design is being simulated. An exponential loss of pressure transient was simulated. This LOCA describes a loss of coolant pressure in the primary side over a 20 second time period. The results for the simulation indicate that heat is initially transferred from the primary loop to the secondary loop, but after the loss of pressure occurs, heat transfers from the secondary loop to the primary loop.

  4. Consumer life-cycle cost impacts of energy-efficiency standards for residential-type central air conditioners and heat pumps

    International Nuclear Information System (INIS)

    In support of the federal government's efforts to raise the minimum energy-efficiency standards for residential-type central air conditioners and heat pumps, a consumer life-cycle cost (LCC) analysis was conducted to demonstrate the economic impacts on individual consumers from revisions to the standards. LCC is the consumer's cost of purchasing and installing an air conditioner or heat pump and operating the unit over its lifetime. The LCC analysis is conducted on a nationally representative sample of air conditioner and heat pump consumers resulting in a distribution of LCC impacts showing the percentage of consumers that are either benefiting or being burdened by increased standards. Relative to the existing minimum efficiency standard of 10 SEER, the results show that a majority of split system air conditioner and heat pump consumers will either benefit or be insignificantly impacted by increased efficiency standards of up to 13 SEER

  5. Cost benefits from applying advanced heat rejection concepts to a wet/dry-cooled binary geothermal plant

    Energy Technology Data Exchange (ETDEWEB)

    Faletti, D.W.

    1981-03-01

    Optimized ammonia heat rejection system designs were carried out for three water allocations equivalent to 9, 20, and 31% of that of a 100% wet-cooled plant. The Holt/Procon design of a 50-MWe binary geothermal plant for the Heber site was used as a design basis. The optimization process took into account the penalties for replacement power, gas turbine capital, and lost capacity due to increased heat rejection temperature, as well as added base plant capacity and fuel to provide fan and pump power to the heat rejection system. Descriptions of the three plant designs are presented. For comparison, a wet tower loop was costed out for a 100% wet-cooled plant using the parameters of the Holt/Procon design. Wet/dry cooling was found to increase the cost of electricity by 28% above that of a 100% wet-cooled plant for all three of the water allocations studied (9, 20, and 31%). The application selected for a preconceptual evaluation of the BCT (binary cooling tower) system was the use of agricultural waste water from the New River, located in California's Imperial Valley, to cool a 50-MWe binary geothermal plant. Technical and cost evaluations at the preconceptual level indicated that performance estimates provided by Tower Systems Incorporated (TSI) were reasonable and that TSI's tower cost, although 2 to 19% lower than PNL estimates, was also reasonable. Electrical cost comparisonswere made among the BCT system, a conventional 100% wet system, and a 9% wet/dry ammonia system, all using agricultural waste water with solar pond disposal. The BCT system cost the least, yielding a cost of electricity only 13% above that of a conventional wet system using high quality water and 14% less than either the conventional 100% wet or the 9% wet/dry ammonia system.

  6. Traditional drug therapies from various medicinal plants of central Karakoram National Park, Gilgit-Baltistan, Pakistan

    International Nuclear Information System (INIS)

    Traditional medicines derived from indigenous plants play an important role in treating infectious diseases. This study examined traditional medicinal uses of indigenous plants and documented different traditional recipes used by local communities to treat different diseases in Baltistan Region. Forty-seven medicinal plants belonging to 22 families were collected. Twenty-one families were angiosperms, one was a pteridophyte (Equisetaceae), and one a gymnosperm (Ephedraceae). Crude extracts of these medicinal plants were used by the local people for treating diseases in a traditional system of medicine. Ranunculaceae, Asteraceae, Polygonaceae and Rosaceae were the most important families, each having five species with medicinal value. The species were found across a wide range of altitudes, from 2000 m to over 4000 m. (author)

  7. 2011 Pacific Gas and Electric Diablo Canyon Power Plant (DCPP): Los Osos, CA Central Coast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Diablo Canyon Power Plant (DCPP) LiDAR and Imagery datasets are comprised of three separate LiDAR surveys: Diablo Canyon (2010), Los Osos (2011), and San Simeon...

  8. 2010 Pacific Gas and Electric Diablo Canyon Power Plant (DCPP): Diablo Canyon, CA Central Coast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Diablo Canyon Power Plant (DCPP) LiDAR and Imagery datasets are comprised of three separate LiDAR surveys: Diablo Canyon (2010), Diablo Canyon (2010), and San...

  9. 2013 Pacific Gas and Electric Diablo Canyon Power Plant (DCPP): San Simeon, CA Central Coast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Diablo Canyon Power Plant (DCPP) LiDAR and Imagery datasets are comprised of three separate LiDAR surveys: Diablo Canyon (2010), Los Osos (2011), and San Simeon...

  10. CO2 capture processes in power plants - Le captage du CO2 dans les centrales thermiques

    CERN Document Server

    Bouallou, Chakib

    2010-01-01

    This review is devoted to assess and compare various processes aiming at recover CO2 from power plants fed with natural gas (NGCC) and pulverized coal (PC). These processes are post combustion CO2 capture using chemical solvents, natural gas reforming for pre-combustion capture and oxy-fuel combustion with cryogenic recovery of CO2. These processes were evaluated to give some clues for choosing the best option for each type of power plant. The comparison of these various concepts suggests that, in the short and medium term, chemical absorption is the most interesting process for NGCC power plants. For CP power plants, oxy-combustion can be a very interesting option, as well as post-combustion capture by chemical solvents.

  11. Comparison of Tobacco Host Cell Protein Removal Methods by Blanching Intact Plants or by Heat Treatment of Extracts.

    Science.gov (United States)

    Buyel, Johannes F; Hubbuch, Jürgen; Fischer, Rainer

    2016-01-01

    Plants not only provide food, feed and raw materials for humans, but have also been developed as an economical production system for biopharmaceutical proteins, such as antibodies, vaccine candidates and enzymes. These must be purified from the plant biomass but chromatography steps are hindered by the high concentrations of host cell proteins (HCPs) in plant extracts. However, most HCPs irreversibly aggregate at temperatures above 60 °C facilitating subsequent purification of the target protein. Here, three methods are presented to achieve the heat precipitation of tobacco HCPs in either intact leaves or extracts. The blanching of intact leaves can easily be incorporated into existing processes but may have a negative impact on subsequent filtration steps. The opposite is true for heat precipitation of leaf extracts in a stirred vessel, which can improve the performance of downstream operations albeit with major changes in process equipment design, such as homogenizer geometry. Finally, a heat exchanger setup is well characterized in terms of heat transfer conditions and easy to scale, but cleaning can be difficult and there may be a negative impact on filter capacity. The design-of-experiments approach can be used to identify the most relevant process parameters affecting HCP removal and product recovery. This facilitates the application of each method in other expression platforms and the identification of the most suitable method for a given purification strategy.

  12. Comparison of Tobacco Host Cell Protein Removal Methods by Blanching Intact Plants or by Heat Treatment of Extracts.

    Science.gov (United States)

    Buyel, Johannes F; Hubbuch, Jürgen; Fischer, Rainer

    2016-01-01

    Plants not only provide food, feed and raw materials for humans, but have also been developed as an economical production system for biopharmaceutical proteins, such as antibodies, vaccine candidates and enzymes. These must be purified from the plant biomass but chromatography steps are hindered by the high concentrations of host cell proteins (HCPs) in plant extracts. However, most HCPs irreversibly aggregate at temperatures above 60 °C facilitating subsequent purification of the target protein. Here, three methods are presented to achieve the heat precipitation of tobacco HCPs in either intact leaves or extracts. The blanching of intact leaves can easily be incorporated into existing processes but may have a negative impact on subsequent filtration steps. The opposite is true for heat precipitation of leaf extracts in a stirred vessel, which can improve the performance of downstream operations albeit with major changes in process equipment design, such as homogenizer geometry. Finally, a heat exchanger setup is well characterized in terms of heat transfer conditions and easy to scale, but cleaning can be difficult and there may be a negative impact on filter capacity. The design-of-experiments approach can be used to identify the most relevant process parameters affecting HCP removal and product recovery. This facilitates the application of each method in other expression platforms and the identification of the most suitable method for a given purification strategy. PMID:27584939

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

    OpenAIRE

    Masayuki Fujita; Md. Mahabub Alam; Rajib Roychowdhury; Mirza Hasanuzzaman; Kamrun Nahar

    2013-01-01

    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 adapt...

  14. Possible uses of sewage sludge from the central wastewater treatment plant Jesenice

    OpenAIRE

    Nučič, Maja

    2016-01-01

    The introductory part of the diploma thesis describes the basics of wastewater and sewage sludge treatment in municipal wastewater treatment plants. The thesis then summarizes the Slovene legislation, which regulates the future usage of sewage sludge in Slovenia. Next, it outlines the alternatives to sewage sludge treatment in wastewater treatment plants and introduces the origins of sewage and the ways of how to reduce or even remove water pollutants at their sources. The practic...

  15. Endangered plant species of the Nevada Test Site, Ash Meadows, and Central-Southern Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Beatley, J.C.

    1977-02-01

    A total of 15 vascular plant taxa, currently appearing on the Endangered Species list, occur in southern Nye County, Nevada, and/or adjacent Inyo County, California. It is the purpose of this report to record in detail the locations of the plant collections upon which the distributions are based, and other information relevant to their status as Endangered Species, and to recommend the areas to be designated critical habitats.

  16. Nuclear power plants making a comeback in Japan; El retorno de la centrales nucleares en Japon

    Energy Technology Data Exchange (ETDEWEB)

    Torralbo, J. R.

    2016-08-01

    We reproduce in this magazine the interesting article published by the president of the SNE in issue 46 of Cuadernos de Energia in October 2015, which describes the events that have taken place since the March 11, 2011 earthquake in Japan, the largest in its history, and the subsequent tsunami, which affected the Fukushima power plant, as well as the measures implemented since then and how some of this country nuclear power plants are being started up again. (Author)

  17. Electrochemical techniques application in corrosion problems of fossil power plants; Aplicacion de tecnicas electroquimicas en problemas de corrosion en centrales termoelectricas

    Energy Technology Data Exchange (ETDEWEB)

    Cano Castillo, Ulises; Garcia Ochoa, Esteban Miguel; Martinez Villafane, Alberto; Mariaca Rodriguez, Liboria; Malo Tamayo, Jose Maria; Uruchurtu Chavarin, Jorge [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1990-12-31

    Some aspects of the electrochemical techniques employed to evaluate the corrosion at low temperature in fossil power plants are commented, as well as the results obtained with the application of them in three power plants of this type. [Espanol] Se comentan algunos aspectos de tecnicas electroquimicas utilizadas para evaluar la corrosion en baja temperatura en centrales termoelectricas, asi como los resultados de la aplicacion de las mismas en tres centrales de este tipo.

  18. Adjustment of machine equipment in heating plants to facilitate addition of straw fuel; Anpassning av vaermeverksutrustning till halminblandning

    Energy Technology Data Exchange (ETDEWEB)

    Stridsberg, Sven [BIOSYD (Sweden)

    1999-10-01

    The ground of the project is a development work, carried out by BIOSYD according combustion of straw in heating plants. First we have handled combustion experiments with addition of straw in some plants working with wood fuels, mainly with good results. In the next step we have worked with new techniques for handling and delivery of straw to the plants, also including experiments with chopping of the straw on the field, storing it in outdoor uncovered piles and consequently delivered in the shape of 'chips' to the heating plant. The whole cycle from cutting to combustion has been checked. The results indicate a possible price of the straw at the heating plant of approx 85 SEK/MWh, which can easily compete with wood fuels. The present project will describe which adjustments of the machine equipment are needed to allow a 25 % addition of straw in the fuel mix, how much these adjustments will cost and if they should be profitable in competition with wood fuels for 110 SEK/MWh. In total 37 heating plants from Skaane up to Uppland have been visited and the process from fuel reception to combustion analyzed. The costs of adjustments needed have been calculated from similar examples. The main impression from the studies is that the fuel reception has too small volumes to allow more numerous kinds of fuel and specially make it possible to give a good mix. This is often not critical for wood fuels but for straw we must guarantee a good mix to get a good combustion. Other critical points are crossings between conveyors, for example dips and feeding out devices, which often have to be adjusted. In the combustion there is a risk for sintering as well as coatings on tubes and walls. These functions must be avoided by air distribution, feed back of fuel gas and better carbon removing. In our analyses we would have judged on results from practical tests, but as this would have been too extensive, we must trust in former experiences, transferred to respective plants. Our

  19. Base-Load and Peak Electricity from a Combined Nuclear Heat and Fossil Combined-Cycle Plant

    International Nuclear Information System (INIS)

    A combined-cycle power plant is proposed that uses heat from a high-temperature reactor and fossil fuel to meet base-load and peak electrical demands. The high temperature gas turbine produces shaft power to turn an electric generator. The hot exhaust is then fed to a heat recovery steam generator (HRSG) that provides steam to a steam turbine for added electrical power production. A simplified computational model of the thermal power conversion system was developed in order to parametrically investigate two different steady-state operation conditions: base load nuclear heat only from an Advanced High Temperature Reactor (AHTR), and combined nuclear heat with fossil heat to increase the turbine inlet temperature. These two cases bracket the expected range of power levels, where any intermediate power level can result during electrical load following. The computed results indicate that combined nuclear-fossil systems have the potential to offer both low-cost base-load electricity and lower-cost peak power relative to the existing combination of base-load nuclear plants and separate fossil-fired peak-electricity production units. In addition, electric grid stability, reduced greenhouse gases, and operational flexibility can also result with using the conventional technology presented here for the thermal power conversion system coupled with the AHTR. (authors)

  20. Base-Load and Peak Electricity from a Combined Nuclear Heat and Fossil Combined-Cycle Plant

    International Nuclear Information System (INIS)

    A combined-cycle power plant is proposed that uses heat from a high-temperature reactor and fossil fuel to meet base-load and peak electrical demands. The high-temperature gas turbine produces shaft power to turn an electric generator. The hot exhaust is then fed to a heat recovery steam generator (HRSG) that provides steam to a steam turbine for added electrical power production. A simplified computational model of the thermal power conversion system was developed in order to parametrically investigate two different steady-state operation conditions: base load nuclear heat only from an Advanced High Temperature Reactor (AHTR), and combined nuclear heat with fossil heat to increase the turbine inlet temperature. These two cases bracket the expected range of power levels, where any intermediate power level can result during electrical load following. The computed results indicate that combined nuclear-fossil systems have the potential to offer both low-cost base-load electricity and lower-cost peak power relative to the existing combination of base-load nuclear plants and separate fossil-fired peak-electricity production units. In addition, electric grid stability, reduced greenhouse gases, and operational flexibility can also result with using the conventional technology presented here for the thermal power conversion system coupled with the AHTR

  1. Physico-chemical change and heat stability of extra virgin olive oils flavoured by selected Tunisian aromatic plants.

    Science.gov (United States)

    Ayadi, M A; Grati-Kamoun, N; Attia, H

    2009-10-01

    Objectives of this work were studying physico-chemical change and heat stability of olive oils flavoured by selected Tunisian aromatic plants. Flavoured olive oils were prepared by maceration of fresh plant materials (rosemary, lavender, sage, menthe, basil, lemon and thyme) with olive oil at a 5% w/w level for 15 days. A sensorial evaluation was applied to select more appreciate flavoured olive oils by consumers. An oxidative procedure was applied to test the stability of selected flavoured olive oils: oils samples were kept in glass bottles and heated at 60 and 130 degrees C during 55 days and 6h, respectively. The resistance to oxidation of these selected flavoured oils was compared to a control samples by measuring PV, K232 and K270 values and change in chlorophyll, carotenes and polyphénols contents. Obtained results show that addition of aromatic plants causes a slight increase in free acidity and viscosity of aromatised olive oils. L*, b* and a* values show that addition of thyme cause a great change in olive oil colours. Heat stability results shows that from selected aromatic plants, rosemary was effectiveness against oxidation followed by thyme and lemon. However, olive oil flavoured with basil exhibit a similar behaviour versus thermal oxidation then the natural olive oil. PMID:19635520

  2. Computer Security for Commercial Nuclear Power Plants - Literature Review for Korea Hydro Nuclear Power Central Research Institute

    Energy Technology Data Exchange (ETDEWEB)

    Duran, Felicia Angelica [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Security Systems Analysis Dept.; Waymire, Russell L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Security Systems Analysis Dept.

    2013-10-01

    Sandia National Laboratories (SNL) is providing training and consultation activities on security planning and design for the Korea Hydro and Nuclear Power Central Research Institute (KHNPCRI). As part of this effort, SNL performed a literature review on computer security requirements, guidance and best practices that are applicable to an advanced nuclear power plant. This report documents the review of reports generated by SNL and other organizations [U.S. Nuclear Regulatory Commission, Nuclear Energy Institute, and International Atomic Energy Agency] related to protection of information technology resources, primarily digital controls and computer resources and their data networks. Copies of the key documents have also been provided to KHNP-CRI.

  3. Trigeneration scheme for energy efficiency enhancement in a natural gas processing plant through turbine exhaust gas waste heat utilization

    International Nuclear Information System (INIS)

    Highlights: ► Efficiency enhancement of Natural Gas (NG) processing plants in hot/humid climates. ► Gas turbine waste heat powered trigeneration scheme using absorption refrigeration. ► Annual NG savings of 1879 MSCM and operating cost savings of US$ 20.9 million realized. ► Trigeneration scheme payback period estimated at approximately 1 year. ► Significant economical and environmental benefits for NG processing plants. - Abstract: The performance of Natural Gas Processing Plants (NGPPs) can be enhanced with the integration of Combined Cooling, Heating and Power (CCHP) generation schemes. This paper analyzes the integration of a trigeneration scheme within a NGPP, that utilizes waste heat from gas turbine exhaust gases to generate process steam in a Waste Heat Recovery Steam Generator (WHRSG). Part of the steam generated is used to power double-effect water–lithium bromide (H2O–LiBr) absorption chillers that provide gas turbine compressor inlet air-cooling. Another portion of the steam is utilized to meet part furnace heating load, and supplement plant electrical power in a combined regenerative Rankine cycle. A detailed techno-economic analysis of scheme performance is presented based on thermodynamic predictions obtained using Engineering Equation Solver (EES). The results indicate that the trigeneration system could recover 79.7 MW of gas turbine waste heat, 37.1 MW of which could be utilized by three steam-fired H2O–LiBr absorption chillers to provide 45 MW of cooling at 5 °C. This could save approximately 9 MW of electric energy required by a typical compression chiller, while providing the same amount of cooling. In addition, the combined cycle generates 22.6 MW of additional electrical energy for the plant, while process heating reduces furnace oil consumption by 0.23 MSCM per annum. Overall, the trigeneration scheme would result in annual natural gas fuel savings of approximately 1879 MSCM, and annual operating cost savings of

  4. Resolution of the direct containment heating issue for all Westinghouse plants with large dry containments or subatmospheric containments

    Energy Technology Data Exchange (ETDEWEB)

    Pilch, M.M.; Allen, M.D.; Klamerus, E.W. [Sandia National Labs., Albuquerque, NM (United States)

    1996-02-01

    This report uses the scenarios described in NUREG/CR-6075 and NUREG/CR-6075, Supplement 1, to address the direct containment heating (DCH) issue for all Westinghouse plants with large dry or subatmospheric containments. DCH is considered resolved if the conditional containment failure probability (CCFP) is less than 0.1. Loads versus strength evaluations of the CCFP were performed for each plant using plant-specific information. The DCH issue is considered resolved for a plant if a screening phase results in a CCFP less than 0.01, which is more stringent than the overall success criterion. If the screening phase CCFP for a plant is greater than 0.01, then refined containment loads evaluations must be performed and/or the probability of high pressure at vessel breach must be analyzed. These analyses could be used separately or could be integrated together to recalculate the CCFP for an individual plant to reduce the CCFP to meet the overall success criterion of less than 0.1. The CCFPs for all of the Westinghouse plants with dry containments were less than 0.01 at the screening phase, and thus, the DCH issue is resolved for these plants based on containment loads alone. No additional analyses are required.

  5. Heat transfer equipment performance diagnosis of auxiliary systems in electric power stations; Diagnostico de comportamiento de equipo de transferencia de calor de sistemas auxiliares de centrales termoelectricas

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Esparza Gutierrez, Rogelio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1990-12-31

    In this article the methodology followed to diagnose the performance of the equipment where heat is transferred from the feed water, condensate and circulation water systems in fossil power plants (FPP). The data collection is made with the unit in normal operation, using local instrumentation without taking the equipment out of service for its installation. The equipment diagnosis is made through the analysis of the collected data in actual operation and the design data; for this purpose a thermal balance of the interested systems is performed to obtain all the conditions an operation data. Later on the performance indicative parameters (PIP) of actual operation and design are calculated and compared one against the other. Such a comparison reveals the performance deterioration and the possible equipment faults. The data obtained and the supplementary information are stored in a data base whose objective is that Comision Federal de Electricidad has on hand a prompt access to them in order to control the performance, compare them among similar units and power stations, and inclusively verify possible recurrent causes of low availability in the referred systems. [Espanol] En este articulo se presenta la metodologia seguida para diagnosticar el comportamiento de equipos en los que se transfiere calor de los sistemas de agua de alimentacion, condensado y circulacion de las centrales termoelectricas (CTE). La toma de datos se realiza con la unidad en operacion normal, utilizando instrumentacion local sin necesidad de sacar de servicio a los equipos para su instalacion, ya que se ocupan los mismos puntos para instrumentos con que cuentan por diseno. El diagnostico de los equipos se realiza mediante el analisis de los datos recopilados, tanto de operacion real como de diseno; para ello, se efectua un balance termico de los sistemas de interes para obtener todas las condiciones y los datos de operacion. Posteriormente, se calculan los parametros indicativos de

  6. Evaluation of cable ageing in Nuclear Power Plants; Evaluacion del envejecimiento de cables en centrales nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Vergara, T. [Empresarios Agrupados, A. I. E. Madrid (Spain); Alonso Chicote, J. [TECNATOM, S. A. (Spain); Burnay, S. [AEA Technology (UK)

    2000-07-01

    The majority of power, control and instrumentation cables in nuclear power plants use polymers as their basic material for insulation and jacket. In many cases, these cables form part of safety-related circuits and should therefore be capable of operating correctly under both normal and accident conditions. Since polymeric materials are degraded by the long term action of the radiation and thermal environments found in the plant, it is important to be able to establish the cable condition during the plant lifetime. Nowadays there are a number of different methods to evaluate the remaining lifetime of cables. In the case of new plants, or new cables in old plants, accelerated ageing tests and predictive models can be used to establish the behaviour of the cable materials under operating conditions. There are verified techniques and considerable experience in the definition of predictive models. This type of approach is best carried out during the commissioning stage or in the early stages of operation. In older plants, particularly where there is a wide range of cable types in use, it is more appropriate to use condition monitoring methods to establish the state of degradation of cables in-plant. Over the last 10 years there have been considerable developments in methods for condition monitoring of cables and a tool-box of practical techniques are now available. There is no single technique which is suitable for all cable materials but the range of methods covers nearly all of the types currently in use, at present, the most established methods are the indented, thermal analysis (OIT, OITP and TGA) and dielectric loss measurements, All of these are either non-destructive methods or require only micro-samples of material. (Author) 15 refs.

  7. Diurnal variability of heat fluxes and heat content at a few locations off central east coast of India during April 1989

    Digital Repository Service at National Institute of Oceanography (India)

    Sadhuram, Y.; Rao, B.P.; Rao, V.S.; Rao, T.V.N.

    Diurnal variability of surface wind speed, net heat exchange, sea surface temperature, vertical thermal structure and heat content at three locations, viz., station A (17 degrees 59'N, 83 degrees 53.9'E), station B (17 degrees 00'N, 82 degrees 32...

  8. Effects caused by the internal heat exchanger at the low temperature cycle in a cascade refrigeration plant

    OpenAIRE

    Llopis Doménech, Rodrigo; Sanz Kock, Carlos; Cabello López, Ramón; Sánchez García-Vacas, Daniel; Nebot-Andrés, Laura; Catalán-Gil, Jesús

    2016-01-01

    This work analyses and quantifies the effects caused by the use of an internal heat exchanger (IHX) at the CO2 subcritical cycle in an HFC134a/CO2 cascade refrigeration plant that incorporates a gas-cooler at the exit of the low temperature compressor. Previous theoretical and experimental studies showed that the IHX reduces the refrigeration capacity and COP of the subcritical cycle, however, it has been seen that it also lowers the heat to be rejected at the condenser. This redu...

  9. Thermal and hydraulic analysis of 3-stream multi fluid (He/He/N2) plate fin heat exchanger for helium plant

    International Nuclear Information System (INIS)

    One of the key components of helium refrigerator/liquefier (HRL) plant is heat exchangers working at cryogenic temperature. For some cases, heat exchangers with effectiveness less than 90% can be a reason for failure of helium plant to produce liquid helium. To achieve such high effectiveness, it is necessary to use plate fin heat exchangers, which provides very high heat transfer surface area per unit volume. For the heat exchangers of HRL, high effectiveness, compact volume and low pressure drop are main optimizing parameters. The first heat exchanger whose temperature range is ∼310 K to ∼90 K is analysed with plate-fin type heat exchanger. This heat exchanger is a part of indigenous development work of HRL of ∼2 kW cooling capacity at 4.5 Kat IPR. Liquid nitrogen (LN2) is used to cool incoming hot He gas around ∼80 K. The detailed thermal and hydraulic analysis is discussed in this paper. (author)

  10. Planting the Seeds of a New Agriculture: Living with the Land in Central America.

    Science.gov (United States)

    Adriance, Jim

    1995-01-01

    Central America's macroeconomics, land tenure patterns, and population growth are forcing small-scale farmers to alternatives based on farmer-to-farmer teaching and farming in concert with the environment. Discusses major schools of thought that have fueled this phenomenon, and how extension services and isolated groups are joining to form a…

  11. 77 FR 50767 - Endangered and Threatened Wildlife and Plants; Endangered Status for Four Central Texas...

    Science.gov (United States)

    2012-08-22

    ... primary threat to the four central Texas salamander species. Water quality degradation in salamander... the Texas State Data Center (2008, p. 1) estimate that Travis County will increase in population from... size over this 40-year period. The Texas State Data Center also estimates an increase in...

  12. Heat-induced release of epigenetic silencing reveals the concealed role of an imprinted plant gene.

    OpenAIRE

    Sanchez, Diego H.; Jerzy Paszkowski

    2014-01-01

    Epigenetic mechanisms suppress the transcription of transposons and DNA repeats; however, this suppression can be transiently released under prolonged heat stress. Here we show that the Arabidopsis thaliana imprinted gene SDC, which is silent during vegetative growth due to DNA methylation, is activated by heat and contributes to recovery from stress. SDC activation seems to involve epigenetic mechanisms but not canonical heat-shock perception and signaling. The heat-mediated transcriptional ...

  13. Central Receiver Solar Thermal Power System, Phase 1. CDRL Item 2. Pilot Plant preliminary design report. Volume III, Book 1. Collector subsystem

    Energy Technology Data Exchange (ETDEWEB)

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

    1977-10-01

    The central receiver system consists of a field of heliostats, a central receiver, a thermal storage unit, an electrical power generation system, and balance of plant. This volume discusses the collector field geometry, requirements and configuration. The development of the collector system and subsystems are discussed and the selection rationale outlined. System safety and availability are covered. Finally, the plans for collector portion of the central receiver system are reviewed.

  14. Gas heat treatment plants for the aluminium industry; Gasbeheizte Waermebehandlungsanlagen fuer die Aluminium-Industrie

    Energy Technology Data Exchange (ETDEWEB)

    Olberts, P.; Hanus, A. [LOI Thermprocess GmbH, Essen (Germany)

    2004-09-01

    LOI Thermoprocess has developed new, flexible, innovative furnace designs for heat treatment of aluminium in general (car industry) and particularly for cylinder heads, engine units, chassis components, textured components, wheels, rolled sheet and extrusions. The furnaces are heated by means of radiant tubes (recuperators) and by the more usual open gas heating system (flue gas recirculation). (orig.)

  15. Vascular plant species richness in relation to altitudinal and slope gradients in mountain landscapes of central norway

    Science.gov (United States)

    Holten, Jarle I.

    Local plant ecological investigations in the central Norwegian mountains in 1992-1997 have shown some interesting features regarding the variability of vascular plant species richness along altitudinal gradients. The material reveals two peaks of vascular plant species richness with increasing elevation, a lowland peak at 0-400 m a.s.l. and a peak at the timberline area (upper part of the northern boreal zone), around the inflection line. Mountains with highly acidic bedrock have a vegetation discontinuity around the transition between discontinuous and continuous permafrost (1500 m in the Dovrefjell area), with a change from dwarf shrubs to more graminoid life forms. The angle of slope is decisive for soil-forming processes. The instability of steep slopes prevents the formation and accumulation of organic top-soils. The data show a high, positive correlation between the slope of habitat plots and the richness of vascular plant species, in both the forested and the alpine zones. A working hypothesis is put forward that, due to high substratum instability, steep terrain encourages high species richness due to the greater openness of habitats and the higher pH of the top-soils. It is suggested that this effect of local topography on species richness is strongest around the inflection line.

  16. Impacts of Photovoltaic Power Plant Sitings and Distributed Solar Panels on Meteorology and Air Quality in Central California

    Science.gov (United States)

    Bastien, L. A.; Jin, L.; Brown, N. J.

    2012-12-01

    California's electric utility companies are required to use renewable energy to produce 20% of their power by 2010 and 33% by 2020. A main source of the power will be solar energy because photovoltaic technologies have advanced so much that large scale installations are being built and will be built in the future with even greater capacity. Rather than being a large emission source, these plants affect the ambient environment through albedo changes and by emission reductions associated with not burning fossil fuels to generate the same amount of electricity. Like conventional power plants, their impact on local meteorology and air quality depends on the specific technology, ambient atmospheric conditions, and the spatial location of the plant. Also, as solar panels on commercial and residential rooftops become even more common, the effect of distributed photovoltaic panels on meteorology and air quality is likely to become significant. In this study, we use the Weather Research and Forecasting (WRF) model and the Community Multiscale Air Quality (CMAQ) model at high resolution of 4 km x 4 km over several 5-day high-ozone episodes of the summer 2000 to assess the impact of photovoltaic panels on meteorology and air quality in Central California. We investigate the effect of locating a 1.0 Giga watt solar plant in different locations and the effect of distributed rooftop photovoltaic panels in major Californian cities, with a focus on peak and 8-hour average ozone and 24-hour average PM2.5.

  17. Ground acceleration in a nuclear power plant; Aceleracion del suelo en una central nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Pena G, P.; Balcazar, M.; Vega R, E., E-mail: pablo.pena@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2015-09-15

    A methodology that adopts the recommendations of international organizations for determining the ground acceleration at a nuclear power plant is outlined. Systematic presented here emphasizes the type of geological, geophysical and geotechnical studies in different areas of influence, culminating in assessments of Design Basis earthquake and the earthquake Operating Base. The methodology indicates that in regional areas where the site of the nuclear power plant is located, failures are identified in geological structures, and seismic histories of the region are documented. In the area of detail geophysical tools to generate effects to determine subsurface propagation velocities and spectra of the induced seismic waves are used. The mechanical analysis of drill cores allows estimating the efforts that generate and earthquake postulate. Studies show that the magnitude of the Fukushima earthquake, did not affect the integrity of nuclear power plants due to the rocky settlement found. (Author)

  18. Antimicrobial Activity of Some Medicinal Plants from East and Central Part of Nepal

    Directory of Open Access Journals (Sweden)

    Bimala Subba

    2014-03-01

    Full Text Available To evaluate the antimicrobial activities of extract of eleven plants were examined against four common bacterials. The ethanolic extracts of various plants such as Cissus repens, Hedyotis scandens, Jatropha curcas, Morus alba, Inula cappa, Equisetum ramosissimum, Osyris wightiana, Alternantheria sessilis and Hibiscus lampas investigated individually for antimicrobial activity by disc diffusion method. These were investigated against selected species of Staphylococcus aureus, Escherichia coli, Proteus vulgaris and Klebsiella pneumoniae to find the inhibitory activities of the microbes. The ethanolic extract of C. repens showed considerably high activity against P. vulgaris, E. coli and S. aureus than other extracts.

  19. Preliminary definition and characterization of a solar industrial process heat technology and manufacturing plant for the year 2000

    Energy Technology Data Exchange (ETDEWEB)

    Prythero, T.; Meyer, R. T.

    1980-09-01

    A solar industrial process heat technology and an associated solar systems manufacturing plant for the year 2000 has been projected, defined, and qualitatively characterized. The technology has been defined for process heat applications requiring temperatures of 300/sup 0/C or lower, with emphasis on the 150/sup 0/ to 300/sup 0/C range. The selected solar collector technology is a parabolic trough collector of the line-focusing class. The design, structure, and material components are based upon existing and anticipated future technological developments in the solar industry. The solar system to be manufactured and assembled within a dedicated manufacturing plant is projected to consist of the collector and the major collector components, including reflector, absorber, parabolic trough structure, support stand, tracking drive mechanism, sun-sensing device and control system, couplings, etc. Major manufacturing processes to be introduced into the year 2000 plant operations are glassmaking, silvering, electroplating and plastic-forming. These operations will generate significant environmental residuals not encountered in present-day solar manufacturing plants. Important residuals include chemical vapors, acids, toxic elements (e.g. arsenic), metallic and chemical sludges, fumes from plastics, etc. The location, design, and operations of these sophisticated solar manufacturing plants will have to provide for the management of the environmental residuals.

  20. Heterologous expression of a plant small heat-shock protein enhances Escherichia coli viability under heat and cold stress.

    Science.gov (United States)

    Soto, A; Allona, I; Collada, C; Guevara, M A; Casado, R; Rodriguez-Cerezo, E; Aragoncillo, C; Gomez, L

    1999-06-01

    A small heat-shock protein (sHSP) that shows molecular chaperone activity in vitro was recently purified from mature chestnut (Castanea sativa) cotyledons. This protein, renamed here as CsHSP17. 5, belongs to cytosolic class I, as revealed by cDNA sequencing and immunoelectron microscopy. Recombinant CsHSP17.5 was overexpressed in Escherichia coli to study its possible function under stress conditions. Upon transfer from 37 degrees C to 50 degrees C, a temperature known to cause cell autolysis, those cells that accumulated CsHSP17.5 showed improved viability compared with control cultures. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of cell lysates suggested that such a protective effect in vivo is due to the ability of recombinant sHSP to maintain soluble cytosolic proteins in their native conformation, with little substrate specificity. To test the recent hypothesis that sHSPs may be involved in protection against cold stress, we also studied the viability of recombinant cells at 4 degrees C. Unlike the major heat-induced chaperone, GroEL/ES, the chestnut sHSP significantly enhanced cell survivability at this temperature. CsHSP17.5 thus represents an example of a HSP capable of protecting cells against both thermal extremes. Consistent with these findings, high-level induction of homologous transcripts was observed in vegetative tissues of chestnut plantlets exposed to either type of thermal stress but not salt stress.