WorldWideScience

Sample records for resistance heating systems

  1. Performance of a Heating Block System Designed for Studying the Heat Resistance of Bacteria in Foods

    Science.gov (United States)

    Kou, Xiao-xi; Li, Rui; Hou, Li-xia; Huang, Zhi; Ling, Bo; Wang, Shao-jin

    2016-01-01

    Knowledge of bacteria’s heat resistance is essential for developing effective thermal treatments. Choosing an appropriate test method is important to accurately determine bacteria’s heat resistances. Although being a major factor to influence the thermo-tolerance of bacteria, the heating rate in samples cannot be controlled in water or oil bath methods due to main dependence on sample’s thermal properties. A heating block system (HBS) was designed to regulate the heating rates in liquid, semi-solid and solid foods using a temperature controller. Distilled water, apple juice, mashed potato, almond powder and beef were selected to evaluate the HBS’s performance by experiment and computer simulation. The results showed that the heating rates of 1, 5 and 10 °C/min with final set-point temperatures and holding times could be easily and precisely achieved in five selected food materials. A good agreement in sample central temperature profiles was obtained under various heating rates between experiment and simulation. The experimental and simulated results showed that the HBS could provide a sufficiently uniform heating environment in food samples. The effect of heating rate on bacterial thermal resistance was evaluated with the HBS. The system may hold potential applications for rapid and accurate assessments of bacteria’s thermo-tolerances. PMID:27465120

  2. Performance of a Heating Block System Designed for Studying the Heat Resistance of Bacteria in Foods

    Science.gov (United States)

    Kou, Xiao-Xi; Li, Rui; Hou, Li-Xia; Huang, Zhi; Ling, Bo; Wang, Shao-Jin

    2016-07-01

    Knowledge of bacteria’s heat resistance is essential for developing effective thermal treatments. Choosing an appropriate test method is important to accurately determine bacteria’s heat resistances. Although being a major factor to influence the thermo-tolerance of bacteria, the heating rate in samples cannot be controlled in water or oil bath methods due to main dependence on sample’s thermal properties. A heating block system (HBS) was designed to regulate the heating rates in liquid, semi-solid and solid foods using a temperature controller. Distilled water, apple juice, mashed potato, almond powder and beef were selected to evaluate the HBS’s performance by experiment and computer simulation. The results showed that the heating rates of 1, 5 and 10 °C/min with final set-point temperatures and holding times could be easily and precisely achieved in five selected food materials. A good agreement in sample central temperature profiles was obtained under various heating rates between experiment and simulation. The experimental and simulated results showed that the HBS could provide a sufficiently uniform heating environment in food samples. The effect of heating rate on bacterial thermal resistance was evaluated with the HBS. The system may hold potential applications for rapid and accurate assessments of bacteria’s thermo-tolerances.

  3. EHT Siegmund GmbH: Floor heating systems made of resistant polyurethane

    Energy Technology Data Exchange (ETDEWEB)

    1982-04-01

    The two special features of Siegmund's floor heating system are as follows: first, the insulating material which is said not to lose its quality even after 30 years of operation is based on polyurethane, and secondly, the deep polyethylene shell which covers the insulating layer is also the plate which carries the heating tubes. The advantages are that they are wear resisting, soundproof, they insulate against humidity and reflect heat.

  4. EHT Siegmund GmbH: floor heating systems made of resistant polyurethane

    Energy Technology Data Exchange (ETDEWEB)

    1982-04-01

    The two special features of Siegmund's floor heating system are as follows: first, the insulating material which is said not to lose its quality even after 30 years of operation is based on polyurethane, and secondly, the deep polyethylene shell which covers the insulating layer is also the plate which carries the heating tubes. The advantages are that they are wear resisting, soundproof, they insulate against humidity and reflect heat.

  5. Thermal resistance of Bacillus stearothermophilus spores in different heating systems containing some approved food additives.

    Science.gov (United States)

    López, M; Mazas, M; González, I; González, J; Bernardo, A

    1996-09-01

    The effects of different heating systems on the heat resistance of Bacillus stearothermophilus spores (ATCC 7953, 12980, 15951 and 15952) were investigated. Spores were heated in distilled water, Sorensen buffer (0.18 mol 1-1), McIlvaine buffer (0.0025-0.18 mol 1-1), and several solutions containing sodium chloride (0.06-12%), sodium nitrite (125 ppm), potassium sorbate (0.1%) and sodium benzoate (0.1%) over a wide range of temperatures (115-140 degrees C). D-values obtained for McIlvaine and Sorensen buffers, at the same molarities, were not significantly different (P > 0.05), but decimal reduction times increased as phosphate concentrations in the solutions decreased. The concentrations, in which statistically significant differences (P 0.05).

  6. Heat-resistant materials

    CERN Document Server

    1997-01-01

    This handbook covers the complete spectrum of technology dealing with heat-resistant materials, including high-temperature characteristics, effects of processing and microstructure on high-temperature properties, materials selection guidelines for industrial applications, and life-assessment methods. Also included is information on comparative properties that allows the ranking of alloy performance, effects of processing and microstructure on high-temperature properties, high-temperature oxidation and corrosion-resistant coatings for superalloys, and design guidelines for applications involving creep and/or oxidation. Contents: General introduction (high-temperature materials characteristics, and mechanical and corrosion properties, and industrial applications); Properties of Ferrous Heat-Resistant Alloys (carbon, alloy, and stainless steels; alloy cast irons; and high alloy cast steels); Properties of superalloys (metallurgy and processing, mechanical and corrosion properties, degradation, and protective coa...

  7. Study on the Thermal Resistance of Multi-chip Module High Power LED Packaging Heat Dissipation System

    Directory of Open Access Journals (Sweden)

    Kailin Pan

    2014-10-01

    Full Text Available Thermal resistance is a key technical index which indicates the thermal management of multi-chip module high power LED (MCM-LED packaging heat dissipation system. In this paper, the prototype structure of MCM-LED packaging heat dissipation system is proposed to study the reliable thermal resistance calculation method. In order to analyze the total thermal resistance of the MCM-LED packaging heat dissipation system, three kinds of thermal resistance calculation method including theoretical calculation, experimental testing and finite element simulation are developed respectively. Firstly, based on the thermal resistance network model and the principle of steady state heat transfer, the theoretical value of total thermal resistance is 6.111 K/W through sum of the thermal resistance of every material layer in the major direction of heat flow. Secondly, the thermal resistance experiment is carried out by T3Ster to obtain the experimental result of total thermal resistance, and the value is 6.729 K/W. Thirdly, a three-dimensional finite element model of MCM-LED packaging heat dissipation system is established, and the junction temperature experiment is also performed to calculated the finite element simulated result of total thermal resistance, the value is 6.99 K/W. Finally, by comparing the error of all the three kinds of result, the error of total thermal resistance between the theoretical value and experimental result is 9.2 %, and the error of total thermal resistance between the experimental result and finite element simulation is only about -3.9 %, meanwhile, the main reason of each error is discussed respectively.

  8. A corrosive resistant heat exchanger

    Science.gov (United States)

    Richlen, S.L.

    1987-08-10

    A corrosive and erosive resistant heat exchanger which recovers heat from a contaminated heat stream. The heat exchanger utilizes a boundary layer of innocuous gas, which is continuously replenished, to protect the heat exchanger surface from the hot contaminated gas. The innocuous gas is pumped through ducts or perforations in the heat exchanger wall. Heat from the heat stream is transferred by radiation to the heat exchanger wall. Heat is removed from the outer heat exchanger wall by a heat recovery medium. 3 figs., 3 tabs.

  9. Thermometry of the systemheat-resistant sample - incident plasma stream”

    Science.gov (United States)

    Sargsyan, M. A.; Chinnov, V. F.; Kavyrshin, D. I.; Gadzhiev, M. Kh; Khromov, M. A.; Chistolinov, A. V.; Senchenko, V. N.

    2017-11-01

    To study the interacting systemheat-resistant sample – an incident plasma stream” a setup of synchronized measurement equipment was developed and tested that recorded the main parameters of such interaction. Heat resistance tests were carried out on the samples of MPG-6 grade isotropic graphite, and samples of pyrolytic graphite that were subjected to a long (60 … 100 s) exposure to nitrogen, argon and air plasma streams at atmospheric pressure. As plasma generators a series of plasma torches with a vortex stabilization of the stream and an expanding anode channels was used. The temperature and composition of the plasma in the jet and near the sample were determined using two AvaSpec2048 and AvaSpec3648 scanning optical spectrometers and the MS5402i spectrograph with the Andor matrix at its outlet. The surface temperature of the sample was determined in real time using three independent ways: two pyrometric systems - a high-speed micro-pyrometer FMP1001 and a two-position visualization of the heated sample by high-speed Motion Pro X3 and VS-FAST cameras, and the spectral analysis of the wide-range thermal radiation of the samples. The main method for determining the rate of material loss during the action of a plasma jet on it was to analyze a two-position synchronous visualization of the “jet-sample” system. When a crater was formed on the surface of the sample under the “dagger” effect of a plasma jet, a video recording system of the crater zone was used, backlit using the “laser knife” method.

  10. Borehole Heat Exchanger Systems: Hydraulic Conductivity and Frost-Resistance of Backfill Materials

    Science.gov (United States)

    Anbergen, Hauke; Sass, Ingo

    2016-04-01

    Ground source heat pump (GSHP) systems are economic solutions for both, domestic heating energy supply, as well as underground thermal energy storage (UTES). Over the past decades the technology developed to complex, advanced and highly efficient systems. For an efficient operation of the most common type of UTES, borehole heat exchanger (BHE) systems, it is necessary to design the system for a wide range of carrier fluid temperatures. During heat extraction, a cooled carrier fluid is heated up by geothermal energy. This collected thermal energy is energetically used by the heat pump. Thereby the carrier fluid temperature must have a lower temperature than the surrounding underground in order to collect heat energy. The steeper the thermal gradient, the more energy is transferred to the carrier fluid. The heat injection case works vice versa. For fast and sufficient heat extraction, even over long periods of heating (winter), it might become necessary to run the BHE with fluid temperatures below 0°C. As the heat pump runs periodically, a cyclic freezing of the pore water and corresponding ice-lens growth in the nearfield of the BHE pipes becomes possible. These so called freeze-thaw-cycles (FTC) are a critical state for the backfill material, as the sealing effect eventually decreases. From a hydrogeological point of view the vertical sealing of the BHE needs to be secured at any time (e.g. VDI 4640-2, Draft 2015). The vertical hydraulic conductivity of the BHE is influenced not only by the permeability of the grouting material itself, but by the contact area between BHE pipes and grout. In order to assess the sealing capacity of grouting materials a laboratory testing procedure was developed that measures the vertical hydraulic conductivity of the system BHE pipe and grout. The key features of the procedure are: • assessment of the systeḿs hydraulic conductivity • assessment of the systeḿs hydraulic conductivity after simulation of freeze-thaw-cycle

  11. Heat-resistant inorganic binders.

    Directory of Open Access Journals (Sweden)

    KUDRYAVTSEV Pavel Gennadievich,

    2017-04-01

    Full Text Available The authors consider some aspects of production of inorganic heat-resistant composite materials in which new classes of inorganic binders - the basic salts of various metals – are applied. The possibility to use hydroxochlorides and hydroxonitrates of aluminum, zirconium, chromium and a number of other metals as the binder has been shown. The main products of the thermal decomposition of all types of binders discussed in this paper are nano-dispersed highly refractory oxides. Increased pressure in the manufacture of these materials shifts the position of the minimum of the dependence «production strength – production temperature» in the direction of low temperatures. This effect is caused by decreased film thickness of the binder located between filler particles and hence by increased rate of transfer of the matter to the interface and by facilitated sintering process. Materials based on the systems containing chromium and some other elements in transitional oxidation states are colour. For this reason, they have the worst thermal conductivity under the same heat resistance compared to colorless materials.

  12. An MRI-Compatible High Frequency AC Resistive Heating System for Homeothermic Maintenance in Small Animals.

    Science.gov (United States)

    Gilchrist, Stuart; Gomes, Ana L; Kinchesh, Paul; Kersemans, Veerle; Allen, Philip D; Smart, Sean C

    2016-01-01

    To develop an MRI-compatible resistive heater, using high frequency alternating current (AC), for temperature maintenance of anaesthetised animals. An MRI-compatible resistive electrical heater was formed from narrow gauge wire connected to a high frequency (10-100 kHz) AC power source. Multiple gradient echo images covering a range of echo times, and pulse-acquire spectra were acquired with the wire heater powered using high frequency AC or DC power sources and without any current flowing in order to assess the sensitivity of the MRI acquisitions to the presence of current flow through the heater wire. The efficacy of temperature maintenance using the AC heater was assessed by measuring rectal temperature immediately following induction of general anaesthesia for a period of 30 minutes in three different mice. Images and spectra acquired in the presence and absence of 50-100 kHz AC through the wire heater were indistinguishable, whereas DC power created field shifts and lineshape distortions. Temperature lost during induction of anaesthesia was recovered within approximately 20 minutes and a stable temperature was reached as the mouse's temperature approached the set target. The AC-powered wire heater maintains adequate heat input to the animal to maintain body temperature, and does not compromise image quality.

  13. An MRI-Compatible High Frequency AC Resistive Heating System for Homeothermic Maintenance in Small Animals.

    Directory of Open Access Journals (Sweden)

    Stuart Gilchrist

    Full Text Available To develop an MRI-compatible resistive heater, using high frequency alternating current (AC, for temperature maintenance of anaesthetised animals.An MRI-compatible resistive electrical heater was formed from narrow gauge wire connected to a high frequency (10-100 kHz AC power source. Multiple gradient echo images covering a range of echo times, and pulse-acquire spectra were acquired with the wire heater powered using high frequency AC or DC power sources and without any current flowing in order to assess the sensitivity of the MRI acquisitions to the presence of current flow through the heater wire. The efficacy of temperature maintenance using the AC heater was assessed by measuring rectal temperature immediately following induction of general anaesthesia for a period of 30 minutes in three different mice.Images and spectra acquired in the presence and absence of 50-100 kHz AC through the wire heater were indistinguishable, whereas DC power created field shifts and lineshape distortions. Temperature lost during induction of anaesthesia was recovered within approximately 20 minutes and a stable temperature was reached as the mouse's temperature approached the set target.The AC-powered wire heater maintains adequate heat input to the animal to maintain body temperature, and does not compromise image quality.

  14. An investigation of flow and resistance characteristics of heat exchanger with the 2-D LDV system and visualization technique

    International Nuclear Information System (INIS)

    Wang Zongsen; Shen Xiong; Xu Yuanhui; Bi Shuxun

    1987-12-01

    An experimental study of the heat exchanger which would be used in a nuclear reactor for low temperature heat-supplying is presented. A 2-D Laser Doppler Velocimeter was used as a unique technique to measure the mean velocity and turbulence intensity distributions in different sections of the model. The relationship between the resistance coefficient and Reynolds number also obtained in terms of the total pressure rakes covered by the casings and the wall static pressure pick-up holes. The flow visualization has realized by using a piece of light source with an Argon-Ion laser. It is apparent that the polystyrene particles seeded in the flow can trace the mean flow. The results showed that the self-similar phenomenon exists in the tube bundle flow system. There are some secondary vortices in the cross sections between two passages of the model

  15. Studying heat treatment impact on heat resisting properties of Cr-Ni – A. E. system alloy

    Directory of Open Access Journals (Sweden)

    Sv. Kvon

    2017-01-01

    Full Text Available The article presents the results the impact of heat treatment on iron-n ickel alloys with adding Mo, Nb, Ti and Al, at this the content of chrome was increased in comparison with the classical structure to 40-45%.

  16. Performance Analysis of Photovoltaic Water Heating System

    OpenAIRE

    Matuska, Tomas; Sourek, Borivoj

    2017-01-01

    Performance of solar photovoltaic water heating systems with direct coupling of PV array to DC resistive heating elements has been studied and compared with solar photothermal systems. An analysis of optimum fixed load resistance for different climate conditions has been performed for simple PV heating systems. The optimum value of the fixed load resistance depends on the climate, especially on annual solar irradiation level. Use of maximum power point tracking compared to fixed optimized loa...

  17. Inductance and resistance measurement method for vessel detection and coil powering in all-surface inductive heating systems composed of outer squircle coils

    Directory of Open Access Journals (Sweden)

    Veli Tayfun Kilic

    2017-05-01

    Full Text Available In this work, we investigate a method proposed for vessel detection and coil powering in an all-surface inductive heating system composed of outer squircle coils. Besides conventional circular coils, coils with different shapes such as outer squircle coils are used for and enable efficient all-surface inductive heating. Validity of the method, which relies on measuring inductance and resistance values of a loaded coil at different frequencies, is experimentally demonstrated for a coil with shape different from conventional circular coil. Simple setup was constructed with a small coil to model an all-surface inductive heating system. Inductance and resistance maps were generated by measuring coil’s inductance and resistance values at different frequencies loaded by a plate made of different materials and located at various positions. Results show that in an induction hob for various coil geometries it is possible to detect a vessel’s presence, to identify its material type and to specify its position on the hob surface by considering inductance and resistance of the coil measured on at least two different frequencies. The studied method is important in terms of enabling safe, efficient and user flexible heating in an all-surface inductive heating system by automatically detecting the vessel’s presence and powering on only the coils that are loaded by the vessel with predetermined current levels.

  18. Heat resistant materials and their feasibility issues for a space nuclear transportation system

    International Nuclear Information System (INIS)

    Olsen, C.S.

    1991-01-01

    A number of nuclear propulsion concepts based on solid-core nuclear propulsion are being evaluated for a nuclear propulsion transportation system to support the Space Exploration Initiative (SEI) involving the reestablishment of a manned lunar base and the subsequent exploration of Mars. These systems will require high-temperature materials to meet the operating conditions with appropriate reliability and safety built into these systems through the selection and testing of appropriate materials. The application of materials for nuclear thermal propulsion (NTP) and nuclear electric propulsion (NEP) systems and the feasibility issues identified for their use will be discussed. Some mechanical property measurements have been obtained, and compatibility tests were conducted to help identify feasibility issues. 3 refs., 1 fig., 4 tabs

  19. Heating systems for heating subsurface formations

    Science.gov (United States)

    Nguyen, Scott Vinh [Houston, TX; Vinegar, Harold J [Bellaire, TX

    2011-04-26

    Methods and systems for heating a subsurface formation are described herein. A heating system for a subsurface formation includes a sealed conduit positioned in an opening in the formation and a heat source. The sealed conduit includes a heat transfer fluid. The heat source provides heat to a portion of the sealed conduit to change phase of the heat transfer fluid from a liquid to a vapor. The vapor in the sealed conduit rises in the sealed conduit, condenses to transfer heat to the formation and returns to the conduit portion as a liquid.

  20. Automation of heating system with heat pump

    OpenAIRE

    Ferdin, Gašper

    2016-01-01

    Because of high prices of energy, we are upgrading our heating systems with newer, more fuel efficient heating devices. Each new device has its own control system, which operates independently from other devices in a heating system. With a relatively low investment costs in automation, we can group devices in one central control system and increase the energy efficiency of a heating system. In this project, we show how to connect an oil furnace, a sanitary heat pump, solar panels and a heat p...

  1. Study on high temperature design methodology of heat-resistant materials for GEN-IV systems

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Woo Seog; Kim, D. W.; Kim, S. H.; Kim, W. G.; Kim, J. H.; Park, D. G.; Yoon, J. H.; Lee, H. Y.; Hing, J. H

    2005-08-15

    Analysis of the existing high temperature design and assessment codes such as US(ASME-NH,Draft Code Case for Alloy 617), France(RCC-MR), UK(R5), Japan(BDS/DDS/FDS) for Gen IV reactor structure has been carried out. In addition the scope and fields for research and development is needed in the future have been defined. For assessing the high temperature creep cracks, time dependent fracture mechanics (TDFM) parameters of the C and Ct were analyzed. The creep propagation data were obtained from the creep crack growth tests for type 316LN stainless steels, and creep crack growth testing machine for Gen-IV system up to 950 .deg. C was set up. Damage mechanism and causes for creep-fatigue were investigated. The difference between prediction creep-fatigue life and experimental life were investigated. Material properties for analysis creep-fatigue damage were recommended. The assessment procedure (Draft) on creep-fatigue crack initiation has been developed based on the technical appendix A16 of French RCC-MR code. Ultrasonic wave signal against creep ruptured specimens of type 316LN stainless steel was obtained. It was identified that creep damage can be evaluated by ultrasonic method. The NDT techniques evaluated include Barkhausen noise, magnetic hysteresis parameters, positron annihilation, X-ray diffraction and small angle neutron scattering. Experimental procedure and evaluation method of material integrity were developed through the fracture toughness test of Cr-Mo steel.

  2. Induction and direct resistance heating theory and numerical modeling

    CERN Document Server

    Lupi, Sergio; Aliferov, Aleksandr

    2015-01-01

    This book offers broad, detailed coverage of theoretical developments in induction and direct resistance heating and presents new material on the solution of problems in the application of such heating. The physical basis of induction and conduction heating processes is explained, and electromagnetic phenomena in direct resistance and induction heating of flat workpieces and cylindrical bodies are examined in depth. The calculation of electrical and energetic characteristics of induction and conduction heating systems is then thoroughly reviewed. The final two chapters consider analytical solutions and numerical modeling of problems in the application of induction and direct resistance heating, providing industrial engineers with the knowledge needed in order to use numerical tools in the modern design of installations. Other engineers, scientists, and technologists will find the book to be an invaluable reference that will assist in the efficient utilization of electrical energy.

  3. Improved solar heating systems

    Science.gov (United States)

    Schreyer, J.M.; Dorsey, G.F.

    1980-05-16

    An improved solar heating system is described in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75 to 180/sup 0/F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing ad releasing heat for distribution.

  4. Solar heating system

    Science.gov (United States)

    Schreyer, James M.; Dorsey, George F.

    1982-01-01

    An improved solar heating system in which the incident radiation of the sun is absorbed on collector panels, transferred to a storage unit and then distributed as heat for a building and the like. The improvement is obtained by utilizing a storage unit comprising separate compartments containing an array of materials having different melting points ranging from 75.degree. to 180.degree. F. The materials in the storage system are melted in accordance with the amount of heat absorbed from the sun and then transferred to the storage system. An efficient low volume storage system is provided by utilizing the latent heat of fusion of the materials as they change states in storing and releasing heat for distribution.

  5. Performance Analysis of Photovoltaic Water Heating System

    Directory of Open Access Journals (Sweden)

    Tomas Matuska

    2017-01-01

    Full Text Available Performance of solar photovoltaic water heating systems with direct coupling of PV array to DC resistive heating elements has been studied and compared with solar photothermal systems. An analysis of optimum fixed load resistance for different climate conditions has been performed for simple PV heating systems. The optimum value of the fixed load resistance depends on the climate, especially on annual solar irradiation level. Use of maximum power point tracking compared to fixed optimized load resistance increases the annual yield by 20 to 35%. While total annual efficiency of the PV water heating systems in Europe ranges from 10% for PV systems without MPP tracking up to 15% for system with advanced MPP trackers, the efficiency of solar photothermal system for identical hot water load and climate conditions is more than 3 times higher.

  6. Exergy performance of different space heating systems: A theoretical study

    DEFF Research Database (Denmark)

    Kazanci, Ongun Berk; Shukuya, Masanori; Olesen, Bjarne W.

    2016-01-01

    Three space heating systems (floor heating with different floor covering resistances, radiator heating with different working temperatures, warm-air heating with and without heat recovery) were compared using a natural gas fired condensing boiler as the heat source. For the floor heating systems......, the effects of floor covering resistance on the whole system performance were studied using two heat sources; a natural gas fired condensing boiler and an air-source heat pump. The heating systems were also compared in terms of auxiliary exergy use for pumps and fans. The low temperature floor heating system...... performed better than other systems in terms of exergy demand. The use of boiler as a heat source for a low-exergy floor heating system creates a mismatch in the exergy supply and demand. Although an air-source heat pump could be a better heat source, this depends on the origin of the electricity supplied...

  7. Optimising corrosion monitoring in district heating systems

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Thorarinsdottir, R.I.; Andersen, A.

    2002-01-01

    A three-year project - financially supported by the Nordic Industrial Fund - on monitoring of corrosion in district heating systems has been initiated with participation of researchers and industrial partners in Denmark, Finland, Iceland, Norway and Sweden. The primary objective of the project...... is to improve the quality control in district heating systems by corrosion monitoring. In Danish systems electrochemical impedance spectroscopy (EIS), linear polarisation resistance (LPR), high-sensitive electrical resistance (ER) technology, crevice corrosion probes, as well as weight loss coupons...

  8. Waste heat recovery system

    International Nuclear Information System (INIS)

    Phi Wah Tooi

    2010-01-01

    Full text: The Konzen in-house designed anaerobic digester system for the POME (Palm Oil Mill Effluent) treatment process is one of the registered Clean Development Mechanism (CDM) projects in Malaysia. It is an organic wastewater treatment process which achieves excellent co-benefits objectives through the prevention of water pollution and reduction of greenhouse gas emissions, which is estimated to be 40,000 to 50,000 t-CO 2 per year. The anaerobic digester was designed in mesophile mode with temperature ranging from 37 degree Celsius to 45 degree Celsius. A microorganisms growth is optimum under moderately warm temperature conditions. The operating temperature of the anaerobic digester needs to be maintained constantly. There are two waste heat recovery systems designed to make the treatment process self-sustaining. The heat recovered will be utilised as a clean energy source to heat up the anaerobic digester indirectly. The first design for the waste heat recovery system utilises heat generated from the flue gas of the biogas flaring system. A stainless steel water tank with an internal water layer is installed at the top level of the flare stack. The circulating water is heated by the methane enriched biogas combustion process. The second design utilizes heat generated during the compression process for the biogas compressor operation. The compressed biogas needs to be cooled before being recycled back into the digester tank for mixing purposes. Both the waste heat recovery systems use a design which applies a common water circulation loop and hot water tank to effectively become a closed loop. The hot water tank will perform both storage and temperature buffer functions. The hot water is then used to heat up recycled sludge from 30 degree Celsius to 45 degree Celsius with the maximum temperature setting at 50 degree Celsius. The recycled sludge line temperature will be measured and monitored by a temperature sensor and transmitter, which will activate the

  9. Heat Pipe Systems

    Science.gov (United States)

    1993-01-01

    The heat pipe was developed to alternately cool and heat without using energy or any moving parts. It enables non-rotating spacecraft to maintain a constant temperature when the surface exposed to the Sun is excessively hot and the non Sun-facing side is very cold. Several organizations, such as Tropic-Kool Engineering Corporation, joined NASA in a subsequent program to refine and commercialize the technology. Heat pipes have been installed in fast food restaurants in areas where humid conditions cause materials to deteriorate quickly. Moisture removal was increased by 30 percent in a Clearwater, FL Burger King after heat pipes were installed. Relative humidity and power consumption were also reduced significantly. Similar results were recorded by Taco Bell, which now specifies heat pipe systems in new restaurants in the Southeast.

  10. Plasma treatment of heat-resistant materials

    International Nuclear Information System (INIS)

    Vlasov, V A; Kosmachev, P V; Skripnikova, N K; Bezukhov, K A

    2015-01-01

    Refractory lining of thermal generating units is exposed to chemical, thermal, and mechanical attacks. The degree of fracture of heat-resistant materials depends on the chemical medium composition, the process temperature and the material porosity. As is known, a shortterm exposure of the surface to low-temperature plasma (LTP) makes possible to create specific coatings that can improve the properties of workpieces. The aim of this work is to produce the protective coating on heat-resistant chamotte products using the LTP technique. Experiments have shown that plasma treatment of chamotte products modifies the surface, and a glass-ceramic coating enriched in mullite is formed providing the improvement of heat resistance. For increasing heat resistance of chamotte refractories, pastes comprising mixtures of Bacor, alumina oxide, and chamot were applied to their surfaces in different ratios. It is proved that the appropriate coating cannot be created if only one of heat-resistant components is used. The required coatings that can be used and recommended for practical applications are obtained only with the introduction of powder chamot. The paste composition of 50% chamot, 25% Bacor, and 25% alumina oxide exposed to plasma treatment, has demonstrated the most uniform surface fusion. (paper)

  11. Turbulent resistive heating of solar coronal arches

    Science.gov (United States)

    Benford, G.

    1983-01-01

    The possibility that coronal heating occurs by means of anomalous Joule heating by electrostatic ion cyclotron waves is examined, with consideration given to currents running from foot of a loop to the other. It is assumed that self-fields generated by the currents are absent and currents follow the direction of the magnetic field, allowing the plasma cylinder to expand radially. Ion and electron heating rates are defined within the cylinder, together with longitudinal conduction and convection, radiation and cross-field transport, all in terms of Coulomb and turbulent effects. The dominant force is identified as electrostatic ion cyclotron instability, while ion acoustic modes remain stable. Rapid heating from an initial temperature of 10 eV to 100-1000 eV levels is calculated, with plasma reaching and maintaining a temperature in the 100 eV range. Strong heating is also possible according to the turbulent Ohm's law and by resistive heating.

  12. Heat resistant wire and cable and heat shrinkable tubes

    International Nuclear Information System (INIS)

    Keiji Ueno

    1994-01-01

    Radiation processes have been used in industrial fields (e.g. wire and cable, heat shrinkable tubes) for about 30 years. In Japan, 60 electron beam accelerators were used in R and D, 54 in wire and cable, 24 in tire rubber, 16 in paint curing, 14 in PE foam and 9 accelerators were used in heat shrinkable tubes in 1993. Many properties (e.g. solder resistance, thermal deformation, and solven resistance) of wire and cable are improved by using radiation processes, and many kinds of radiation crosslinked wire and cable are used in the consumer market (TV sets, VTR's, audio disc players, etc.), automobiles (automobile wire harnesses, fusible link wires, sensor cables etc.), and the industrial market (computer cables, cables for keyboards, coaxial cables, etc.). Another important industrial application of Eβ radiation process is heat shrinkable tubes. Heat shinkable tubes, heated by a hot gun, shrink 1/2 ∼ 1/3 of their inner diameters. Heat shrinkable tubes are used for covers of distributing line terminals, joint covers of telecommunication lines, protection of fuel pipe lines and so on. In this seminar, actual applications and characteristic properties of radiation crosslinked materials are presented

  13. Heating Systems Specialist.

    Science.gov (United States)

    Air Force Training Command, Sheppard AFB, TX.

    This instructional package is intended for use in training Air Force personnel enrolled in a program for apprentice heating systems specialists. Training includes instruction in fundamentals and pipefitting; basic electricity; controls, troubleshooting, and oil burners; solid and gas fuel burners and warm air distribution systems; hot water…

  14. Heat transfer system

    International Nuclear Information System (INIS)

    McGuire, J.C.

    1983-01-01

    An intermediate heat exchanger that provides the required physical isolation between the primary reactor coolant loops and a secondary liquid loop in which steam is generated was developed. The intermediate heat exchanger is contained within a sealed vapor chamber that includes a bottom interior portion and an adjacent upper interior portion in vertical communication with one another. The chamber is exhausted of all noncondensible gases at ambient temperature. A heat transfer medium within the chamber maintains a two phase liquid-vapor-liquid system at the design heat transfer temperature. A first set of tubes in the bottom portion of the vapor chamber is supplied with primary reactor coolant. A second set of tubes in the upper portion of the chamber is supplied with water or steam. A thermal linkage is provided between the two sets of tubes by the heat transfer medium, which is evaporated in the vicinity of the first set and is condensed in the vicinity of the second set. This results in a latent heat transport system, condensate return being accomplished by gravity

  15. Thermophysical Properties of Heat Resistant Shielding Material

    International Nuclear Information System (INIS)

    Porter, W.D.

    2004-01-01

    This project was aimed at determining thermal conductivity, specific heat and thermal expansion of a heat resistant shielding material for neutron absorption applications. These data are critical in predicting the structural integrity of the shielding under thermal cycling and mechanical load. The measurements of thermal conductivity and specific heat were conducted in air at five different temperatures (-31 F, 73.4 F, 140 F, 212 F and 302 F). The transient plane source (TPS) method was used in the tests. Thermal expansion tests were conducted using push rod dilatometry over the continuous range from -40 F (-40 C) to 302 F (150 C)

  16. Heat-resistant anemometers for fire research

    Science.gov (United States)

    John R. Murray; Clive M. Countryman

    1968-01-01

    Heat-resistant anemometers have been developed for measuring horizontal and vertical air flow in fire behavior studies. The anemometers will continue to produce data as long as the anemometer body is less than 650°F. They can survive brief immersion in flame without major damage. These air-flow sensors have aluminum bodies and rotor hubs and stainless steel...

  17. Heat pipes as perspective base elements of heat recovery in heat supply and ventilating systems

    Directory of Open Access Journals (Sweden)

    Matveev Andrey

    2017-01-01

    Full Text Available Thermotechnical characteristics of heat pipes are considered as high-efficient heat-transfer devices, which can provide energy-saving technologies for heat supply and ventilating systems and for different branches of industry. Thermotechnical and working (”performance capability” characteristics of heat pipes are investigated. By ”performance capability” of heat pipes and heat-transfer devices on heat pipes we mean the system state, where it can perform set functions and keep parameter values (thermal power, conductivity, thermal resistance, heat-transfer coefficient, temperature level and differential, etc. within the regulations of standardized specifications. The article presents theoretical and experimental methods of «gaslock» length determination on noncondensable gases during long-lasting tests of ammonia heat pipes made of aluminum shape АS – КRА 7.5 – R1 (alloy АD – 31. The paper gives results of research of thermotechnical characteristics of heat pipes in horizontal and vertical states (separate and as a set part while using different systems of thermal insulation. The obtained results of thermotechnical and resource tests show the advantages of ammonia heat pipes as basic elements for heat exchanger design in heating and ventilation systems.

  18. Changes In Mechanical Properties Of Heat Resisting Alloy For A Satellite Propulsion System After A Nitriding Process

    Science.gov (United States)

    Kagawa, Hideshi; Fujii, Go; Kajiwara, Kenichi; Kuroda, Daisuke; Suzuki, Takuya; Yamabe-Mitarai, Yoko; Murakami, Hideyuki; Ono, Yoshinori

    2012-07-01

    Haynes25 (L-605) is a common heat resistant alloy used in mono-propellant structures and screen materials for catalyst beds. The lifetime requirements for thrusters have expanded dramatically after studies conducted in the 1970s on mono-propellant materials used to extend the service life. The material design had long remained unchanged, and the L-605 was still used as thruster material due to its good heritage. However, some important incidents involving degradation were found during the test-unit break-up inspection following the thruster life tests. The Japanese research team focused on the L-605 degradations found on the catalyst bed screen mesh used for mono-propellant thruster and analysed the surface of the wire material and the cross- section of the wire screen mesh used in the life tests. The investigation showed that the degradation was caused by nitriding L-605 component elements. The team suggested that the brittle fracture was attributable to tungsten (W) carbides, which formed primarily in the grain boundaries, and chromium (Cr) nitride, which formed mainly in the parts in contact with the hot firing gas. The team also suggested the installation of a platinum coating on the material surface as a countermeasure L-605 nitric degradation. Inconel 625 is now selected as a mono-propellant structure material due to its marginal raw material characters and cost. The team believes that Inconel 625 does not form W carbides since it contains no tungsten component, but does contain Cr and Fe, which form nitrides easily. Therefore, the team agreed that for the Inconel 625, there was a need to evaluate changes in the microstructure and mechanical properties following exposure to hot nitrogen gases. This paper will describe these changes of Inconel 625.

  19. SIGNAL MEDIATORS AT INDUCTION OF HEAT RESISTANCE OF WHEAT PLANTLETS BY SHORT-TERM HEATING.

    Science.gov (United States)

    Karpets, Yu V; Kolupaev, Yu E; Yastreb, T O

    2015-01-01

    The effects of functional interplay of calcium ions, reactive oxygen species (ROS) and nitric oxide (NO) in the cells of wheat plantlets roots (Triticum aestivum L.) at the induction of their heat resistance by a short-term influence of hyperthermia (heating at the temperature of 42 degrees C during 1 minute) have been investigated. The transitional increase of NO and H2O2 content, invoked by heating, was suppressed by the treatment of plantlets with the antagonists of calcium EGTA (chelator of exocellular calcium), lanthanum chloride (blocker of calcium channels of various types) and neomycin (inhibitor of phosphatidylinositol-dependent phospholipase C). The rise of hydrogen peroxide content, caused by hardening, was partially suppressed by the action of inhibitors of nitrate reductase (sodium wolframate) and NO-synthase (N(G)-nitro-L-arginine methyl ester--L-NAME), and the increasing of nitric oxide content was suppressed by the treatment of plants with the antioxidant ionol and with the scavenger of hydrogen peroxide (dimethylthiourea). These compounds and antagonists of calcium also partially removed the effect of the rise of plantlets' heat resistance, invoked by hardening heating. The conclusion on calcium's role in the activation of enzymatic systems, generating reactive oxygen species and nitric oxide, and on the functional interplay of these signal mediators at the induction of heat resistance of plantlets by hardening heating is made.

  20. Signal mediators at induction of heat resistance of wheat plantlets by short-term heating

    Directory of Open Access Journals (Sweden)

    Yu. V. Karpets

    2015-12-01

    Full Text Available The effects of functional interplay of calcium ions, reactive oxygen species (ROS and nitric oxide (NO in the cells of wheat plantlets roots (Triticum aestivum L. at the induction of their heat resistance by a short-term influence of hyperthermia (heating at the temperature of 42 °С during 1 minute have been investigated. The transitional increase of NO and H2O2 content, invoked by heating, was suppressed by the treatment of plantlets with the antagonists of calcium EGTA (chelator of exocellular calcium, lanthanum chloride (blocker of calcium channels of various types and neomycin (inhibitor of phosphatidylinositol-dependent phospholipase C. The rise of hydrogen peroxide content, caused by hardening, was partially suppressed by the action of inhibitors of nitrate reductase (sodium wolframate and NO-synthase (NG-nitro-L-arginine methyl ester – L-NAME, and the increasing of nitric oxide content was suppressed by the treatment of plants with the antioxidant ionol and with the scavenger of hydrogen peroxide (dimethylthiourea. These compounds and antagonists of calcium also partially removed the effect of the rise of plantlets’ heat resistance, invoked by hardening heating. The conclusion on calcium’s role in the activation of enzymatic systems, generating reactive oxygen species and nitric oxide, and on the functional interplay of these signal mediators at the induction of heat resistance of plantlets by hardening heating is made.

  1. Adriamycin resistance, heat resistance and radiation response in Chinese hamster fibroblasts

    International Nuclear Information System (INIS)

    Wallner, K.; Li, G.

    1985-01-01

    Previous investigators have demonstrated synergistic interaction between hyperthermia and radiation or Adriamycin (ADR), using cell lines that are sensitive to heat or ADR alone. The authors investigated the effect of heat, radiation or ADR on Chinese hamster fibroblasts (HA-1), their heat resistant variants and their ADR resistant variants. Heat for ADR resistance did not confer cross resistance to radiation. Cells resistant to heat did show cross resistance to ADR. While cells selected for ADR resistance were not cross resistant to heat, they did not exhibit drug potentiation by hyperthermia, characteristic of ADR sensitive cells. Cytofluorometric measurement showed decreased ADR uptake in both heat and ADR resistant cells. The possibility of cross resistance between heat and ADR should be considered when designing combined modality trials

  2. Diesel particulate filter regeneration via resistive surface heating

    Science.gov (United States)

    Gonze, Eugene V; Ament, Frank

    2013-10-08

    An exhaust system that processes exhaust generated by an engine is provided. The system includes: a particulate filter (PF) that filters particulates from the exhaust wherein an upstream end of the PF receives exhaust from the engine; and a grid of electrically resistive material that is applied to an exterior upstream surface of the PF and that selectively heats exhaust passing through the grid to initiate combustion of particulates within the PF.

  3. Genetic determinants of heat resistance in Escherichia coli.

    Science.gov (United States)

    Mercer, Ryan G; Zheng, Jinshui; Garcia-Hernandez, Rigoberto; Ruan, Lifang; Gänzle, Michael G; McMullen, Lynn M

    2015-01-01

    Escherichia coli AW1.7 is a heat resistant food isolate and the occurrence of pathogenic strains with comparable heat resistance may pose a risk to food safety. To identify the genetic determinants of heat resistance, 29 strains of E. coli that differed in their of heat resistance were analyzed by comparative genomics. Strains were classified as highly heat resistant strains, exhibiting a D60-value of more than 6 min; moderately heat resistant strains, exhibiting a D60-value of more than 1 min; or as heat sensitive. A ~14 kb genomic island containing 16 predicted open reading frames encoding putative heat shock proteins and proteases was identified only in highly heat resistant strains. The genomic island was termed the locus of heat resistance (LHR). This putative operon is flanked by mobile elements and possesses >99% sequence identity to genomic islands contributing to heat resistance in Cronobacter sakazakii and Klebsiella pneumoniae. An additional 41 LHR sequences with >87% sequence identity were identified in 11 different species of β- and γ-proteobacteria. Cloning of the full length LHR conferred high heat resistance to the heat sensitive E. coli AW1.7ΔpHR1 and DH5α. The presence of the LHR correlates perfectly to heat resistance in several species of Enterobacteriaceae and occurs at a frequency of 2% of all E. coli genomes, including pathogenic strains. This study suggests the LHR has been laterally exchanged among the β- and γ-proteobacteria and is a reliable indicator of high heat resistance in E. coli.

  4. Genetic determinants of heat resistance in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Ryan eMercer

    2015-09-01

    Full Text Available Escherichia coli AW1.7 is a heat resistant food isolate and the occurrence of pathogenic strains with comparable heat resistance may pose a risk to food safety. To identify the genetic determinants of heat resistance, 29 strains of E. coli that differed in their of heat resistance were analyzed by comparative genomics. Strains were classified as highly heat resistant strains, exhibiting a D60-value of more than 6 min; moderately heat resistant strains, exhibiting a D60-value of more than 1 min; or as heat sensitive. A ~14 kb genomic island containing 16 predicted open reading frames encoding putative heat shock proteins and proteases was identified only in highly heat resistant strains. The genomic island was termed the locus of heat resistance (LHR. This putative operon is flanked by mobile elements and possesses >99% sequence identity to genomic islands contributing to heat resistance in Cronobacter sakazakii and Klebsiella pneumoniae. An additional 41 LHR sequences with >87% sequence identity were identified in 11 different species of β- and γ-proteobacteria. Cloning of the full length LHR conferred high heat resistance to the heat sensitive E. coli AW1.7ΔpHR1 and DH5α. The presence of the LHR correlates perfectly to heat resistance in several species of Enterobacteriaceae and occurs at a frequency of 2% of all E. coli genomes, including pathogenic strains. This study suggests the LHR has been laterally exchanged among the β- and γ-proteobacteria and is a reliable indicator of high heat resistance in E. coli.

  5. Genetic determinants of heat resistance in Escherichia coli

    Science.gov (United States)

    Mercer, Ryan G.; Zheng, Jinshui; Garcia-Hernandez, Rigoberto; Ruan, Lifang; Gänzle, Michael G.; McMullen, Lynn M.

    2015-01-01

    Escherichia coli AW1.7 is a heat resistant food isolate and the occurrence of pathogenic strains with comparable heat resistance may pose a risk to food safety. To identify the genetic determinants of heat resistance, 29 strains of E. coli that differed in their of heat resistance were analyzed by comparative genomics. Strains were classified as highly heat resistant strains, exhibiting a D60-value of more than 6 min; moderately heat resistant strains, exhibiting a D60-value of more than 1 min; or as heat sensitive. A ~14 kb genomic island containing 16 predicted open reading frames encoding putative heat shock proteins and proteases was identified only in highly heat resistant strains. The genomic island was termed the locus of heat resistance (LHR). This putative operon is flanked by mobile elements and possesses >99% sequence identity to genomic islands contributing to heat resistance in Cronobacter sakazakii and Klebsiella pneumoniae. An additional 41 LHR sequences with >87% sequence identity were identified in 11 different species of β- and γ-proteobacteria. Cloning of the full length LHR conferred high heat resistance to the heat sensitive E. coli AW1.7ΔpHR1 and DH5α. The presence of the LHR correlates perfectly to heat resistance in several species of Enterobacteriaceae and occurs at a frequency of 2% of all E. coli genomes, including pathogenic strains. This study suggests the LHR has been laterally exchanged among the β- and γ-proteobacteria and is a reliable indicator of high heat resistance in E. coli. PMID:26441869

  6. Waste heat recovery system

    Science.gov (United States)

    Ernst, Timothy C.; Zigan, James A.

    2017-12-19

    A waste heat recovery system includes a Rankine cycle (RC) circuit having a pump, a boiler, an energy converter, and a condenser fluidly coupled via conduits in that order, to provide additional work. The additional work is fed to an input of a gearbox assembly including a capacity for oil by mechanically coupling to the energy converter to a gear assembly. An interface is positioned between the RC circuit and the gearbox assembly to partially restrict movement of oil present in the gear assembly into the RC circuit and partially restrict movement of working fluid present in the RC circuit into the gear assembly. An oil return line is fluidly connected to at least one of the conduits fluidly coupling the RC components to one another and is operable to return to the gear assembly oil that has moved across the interface from the gear assembly to the RC circuit.

  7. Entropy resistance minimization: An alternative method for heat exchanger analyses

    International Nuclear Information System (INIS)

    Cheng, XueTao

    2013-01-01

    In this paper, the concept of entropy resistance is proposed based on the entropy generation analyses of heat transfer processes. It is shown that smaller entropy resistance leads to larger heat transfer rate with fixed thermodynamic force difference and smaller thermodynamic force difference with fixed heat transfer rate, respectively. For the discussed two-stream heat exchangers in which the heat transfer rates are not given and the three-stream heat exchanger with prescribed heat capacity flow rates and inlet temperatures of the streams, smaller entropy resistance leads to larger heat transfer rate. For the two-stream heat exchangers with fixed heat transfer rate, smaller entropy resistance leads to larger effectiveness. Furthermore, it is shown that smaller values of the concepts of entropy generation numbers and modified entropy generation number do not always correspond to better performance of the discussed heat exchangers. - Highlights: • The concept of entropy resistance is defined for heat exchangers. • The concepts based on entropy generation are used to analyze heat exchangers. • Smaller entropy resistance leads to better performance of heat exchangers. • The applicability of entropy generation minimization is conditional

  8. Alloying principles for magnesium base heat resisting alloys

    International Nuclear Information System (INIS)

    Drits, M.E.; Rokhlin, L.L.; Oreshkina, A.A.; Nikitina, N.I.

    1982-01-01

    Some binary systems of magnesium-base alloys in which solid solutions are formed, are considered for prospecting heat resistant alloys. It is shown that elements having essential solubility in solid magnesium strongly decreasing with temperature should be used for alloying maqnesium base alloys with high strength properties at increased temperatures. The strengthening phases in these alloys should comprise essential quantity of magnesium and be rather refractory

  9. Heat Pumps in CHP Systems

    DEFF Research Database (Denmark)

    Ommen, Torben Schmidt

    In the current Danish energy system, the majority of electricity and heat is produced in combined heat and power (CHP) plants. With increasing shares of intermittent renewable power production, it becomes a challenging task to match power and heat production to its demand curves, as production...... that three configurations are particular advantageous, whereas the two remaining configurations result in system performance close to or below what may be expected from an electric heater. One of the three advantageous configurations is required to be positioned at the location of the heat demand, whereas....... Six vapour compression heat pump (VCHP) systems were considered along with the ammonia-water hybrid absorption compression heat pump (HACHP), corresponding to an upper limit of the sink temperature of up to 150 °C. The best available technology was determined for each set of heat sink and source...

  10. Solar Heating System with Building-Integrated Heat Storage

    DEFF Research Database (Denmark)

    Heller, Alfred

    1996-01-01

    Traditional solar heating systems cover between 5 and 10% of the heat demand fordomestic hot water and comfort heating. By applying storage capacity this share can beincreased much. The Danish producer of solar heating systems, Aidt-Miljø, markets such a system including storage of dry sand heated...... by PP-pipe heat exchanger. Heat demand is reduced due to direct solar heating, and due to storage. Heat demand is reduced due to direct solar heating, due to storage and due to lower heat losses through the ground. In theory, by running the system flow backwards through the sand storage, active heating...... can be achieved.The objective of the report is to present results from measured system evaluation andcalculations and to give guidelines for the design of such solar heating systems with building integrated sand storage. The report is aimed to non-technicians. In another report R-006 the main results...

  11. Heating systems with PLC and frequency control

    Energy Technology Data Exchange (ETDEWEB)

    Abdallah, S.; Abu-Malouh, R. [Applied Science Univ., Amman (Jordan). Dept. of Mechanical and Industrial Engineering

    2007-07-01

    Heat treatment involves the controlled heating and cooling of metals to alter their physical and mechanical properties without changing the product shape. Heat treatment is frequently associated with increasing the strength of material, but it can also be utilized to alter certain manufacturability objectives such as improve machining, improve formability, and restoring ductility after a cold working operation. Heat treatment is an enabling process that can help other manufacturing processes, as well as improve product performance by increasing strength or other desirable characteristics. This paper discussed the design and construction of a medium capacity controlled heating system. The programming method of control of the heating process was achieved using an integrated programmable logic controller (PLC) and frequency inverter. An experimental study was performed to investigate the effect of temperature and tempering time on hardness and fatigue resistance of 0.4 per cent carbon steel. The paper discussed the heating system design and control and provided a mathematical description of the frequency controlled heating system. The modeling of the frequency converter and of the furnace was explained. It was concluded that increasing the tempering temperature above 550 degrees Celsius or tempering time decreased the hardness of the material. 26 refs., 16 figs.

  12. Influence of nonmagnetic disorder on specific heat and electrical resistivity in Kondo lattice system CePd{sub 1−x}Ge{sub x}In

    Energy Technology Data Exchange (ETDEWEB)

    Gnida, D., E-mail: d.gnida@int.pan.wroc.pl [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 50-950 Wrocław (Poland); Dominyuk, N.; Zaremba, V. [Inorganic Chemistry Department, Ivan Franko Lviv National University, Kyryla and Mephodiya Str. 6, 79005 Lviv (Ukraine); Kaczorowski, D. [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 50-950 Wrocław (Poland)

    2015-02-15

    Highlights: • Interplay of Kondo and RKKY interactions in the presence of nonmagnetic disorder. • Suppression of the coherent Kondo state by nonmagnetic impurities. • Observation of quantum interference phenomena in Ce-based Kondo system. • Coexistence of incoherent Kondo effect and Altshuler-Aronov quantum correction. - Abstract: The alloy system CePd{sub 1−x}Ge{sub x}In with 0.1⩽x⩽0.4 was investigated by means of heat capacity and electrical resistivity measurements. Its low-temperature behavior has been found to be governed by the interplay of Kondo effect and Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions in the presence of atomic disorder in nonmagnetic atoms sublattice. The coherent Kondo state, observed for CePdIn, gradually vanishes with increasing the Ge-content. The incoherent Kondo state, which characterizes Ge-rich alloys, appears very sensitive to applied magnetic field. The observed systematic changes in the temperature- and field-dependent electrical transport in CePd{sub 1−x}Ge{sub x}In manifest the important role of quantum correction due to electron-electron interactions in weakly localized regime.

  13. Some Like It Hot: Heat Resistance ofEscherichia coliin Food.

    Science.gov (United States)

    Li, Hui; Gänzle, Michael

    2016-01-01

    Heat treatment and cooking are common interventions for reducing the numbers of vegetative cells and eliminating pathogenic microorganisms in food. Current cooking method requires the internal temperature of beef patties to reach 71°C. However, some pathogenic Escherichia coli such as the beef isolate E. coli AW 1.7 are extremely heat resistant, questioning its inactivation by current heat interventions in beef processing. To optimize the conditions of heat treatment for effective decontaminations of pathogenic E. coli strains, sufficient estimations, and explanations are necessary on mechanisms of heat resistance of target strains. The heat resistance of E. coli depends on the variability of strains and properties of food formulations including salt and water activity. Heat induces alterations of E. coli cells including membrane, cytoplasm, ribosome and DNA, particularly on proteins including protein misfolding and aggregations. Resistant systems of E. coli act against these alterations, mainly through gene regulations of heat response including EvgA, heat shock proteins, σ E and σ S , to re-fold of misfolded proteins, and achieve antagonism to heat stress. Heat resistance can also be increased by expression of key proteins of membrane and stabilization of membrane fluidity. In addition to the contributions of the outer membrane porin NmpC and overcome of osmotic stress from compatible solutes, the new identified genomic island locus of heat resistant performs a critical role to these highly heat resistant strains. This review aims to provide an overview of current knowledge on heat resistance of E. coli , to better understand its related mechanisms and explore more effective applications of heat interventions in food industry.

  14. Some Like It Hot: Heat Resistance of Escherichia coli in Food

    Science.gov (United States)

    Li, Hui; Gänzle, Michael

    2016-01-01

    Heat treatment and cooking are common interventions for reducing the numbers of vegetative cells and eliminating pathogenic microorganisms in food. Current cooking method requires the internal temperature of beef patties to reach 71°C. However, some pathogenic Escherichia coli such as the beef isolate E. coli AW 1.7 are extremely heat resistant, questioning its inactivation by current heat interventions in beef processing. To optimize the conditions of heat treatment for effective decontaminations of pathogenic E. coli strains, sufficient estimations, and explanations are necessary on mechanisms of heat resistance of target strains. The heat resistance of E. coli depends on the variability of strains and properties of food formulations including salt and water activity. Heat induces alterations of E. coli cells including membrane, cytoplasm, ribosome and DNA, particularly on proteins including protein misfolding and aggregations. Resistant systems of E. coli act against these alterations, mainly through gene regulations of heat response including EvgA, heat shock proteins, σE and σS, to re-fold of misfolded proteins, and achieve antagonism to heat stress. Heat resistance can also be increased by expression of key proteins of membrane and stabilization of membrane fluidity. In addition to the contributions of the outer membrane porin NmpC and overcome of osmotic stress from compatible solutes, the new identified genomic island locus of heat resistant performs a critical role to these highly heat resistant strains. This review aims to provide an overview of current knowledge on heat resistance of E. coli, to better understand its related mechanisms and explore more effective applications of heat interventions in food industry. PMID:27857712

  15. Solar Heating Systems: Student Manual.

    Science.gov (United States)

    Green, Joanne; And Others

    This Student Manual for a Solar Heating System curriculum contains 22 units of instructional materials for students to use in a course or courses on solar heating systems (see note). For each unit (task), objectives, assignment sheets, laboratory assignments, information sheets, checkpoints (tests), and job sheets are provided. Materials are set…

  16. Solar Heating Systems: Instructor's Guide.

    Science.gov (United States)

    Green, Joanne; And Others

    This Instructor's Guide for a Solar Heating System Curriculum is designed to accompany the Student Manual and the Progress Checks and Test Manual for the course (see note), in order to facilitate the instruction of classes on solar heating systems. The Instructor's Guide contains a variety of materials used in teaching the courses, including…

  17. Entropy resistance analyses of a two-stream parallel flow heat exchanger with viscous heating

    International Nuclear Information System (INIS)

    Cheng Xue-Tao; Liang Xin-Gang

    2013-01-01

    Heat exchangers are widely used in industry, and analyses and optimizations of the performance of heat exchangers are important topics. In this paper, we define the concept of entropy resistance based on the entropy generation analyses of a one-dimensional heat transfer process. With this concept, a two-stream parallel flow heat exchanger with viscous heating is analyzed and discussed. It is found that the minimization of entropy resistance always leads to the maximum heat transfer rate for the discussed two-stream parallel flow heat exchanger, while the minimizations of entropy generation rate, entropy generation numbers, and revised entropy generation number do not always. (general)

  18. Heat transfer entropy resistance for the analyses of two-stream heat exchangers and two-stream heat exchanger networks

    International Nuclear Information System (INIS)

    Cheng, XueTao; Liang, XinGang

    2013-01-01

    The entropy generation minimization method is often used to analyze heat transfer processes from the thermodynamic viewpoint. In this paper, we analyze common heat transfer processes with the concept of entropy generation, and propose the concept of heat transfer entropy resistance. It is found that smaller heat transfer entropy resistance leads to smaller equivalent thermodynamic force difference with prescribed heat transfer rate and larger heat transfer rate with prescribed equivalent thermodynamic force difference. With the concept of heat transfer entropy resistance, the performance of two-stream heat exchangers (THEs) and two-stream heat exchanger networks (THENs) is analyzed. For the cases discussed in this paper, it is found that smaller heat transfer entropy resistance always leads to better heat transfer performance for THEs and THENs, while smaller values of the entropy generation, entropy generation numbers and revised entropy generation number do not always. -- Highlights: • The concept of entropy resistance is defined. • The minimum entropy resistance principle is developed. • Smaller entropy resistance leads to better heat transfer

  19. Structural heat-resistant β-NiAl + γ'-Ni3Al alloys of the Ni-Al-Co system: I. Solidification and structure

    Science.gov (United States)

    Povarova, K. B.; Drozdov, A. A.; Bazyleva, O. A.; Morozov, A. E.; Antonova, A. V.; Bondarenko, Yu. A.; Bulakhtina, M. A.; Ashmarin, A. A.; Arginbaeva, E. G.; Alad'ev, N. A.

    2017-09-01

    When analyzing the ternary Ni-Al- M phase diagrams, where M is a group VI-VIII transition metal, we chose the Ni-Al-Co system, where the γ' and γ phases are in equilibrium with the β phase, as a base for designing alloys with the following physicochemical properties: a moderate density (≤7.2 g/cm3) and satisfactory heat resistance at temperatures up to 1300°C. The structure formation in heterophase β + γ' alloys during directional solidification is studied. It is found that, in contrast to cobalt-free β + γ' alloys (where the γ'-Ni3Al aluminide forms according to the peritectic reaction L + β ⇄ γ'), the alloys with 8-10 at % Co studied in this work during directional solidification at 1370°C contain the degenerate eutectic L ⇄ β + γ. The transition from the β + γ field to the β + γ' + γ field occurs in the temperature range 1323-1334°C, and the γ' phase then forms according to the reaction β + γ ⇄ γ'.

  20. Ground Source Heat Pump in Heating System with Electronics Monitoring

    Directory of Open Access Journals (Sweden)

    NEAMŢU Ovidiu

    2013-10-01

    Full Text Available The monitoring system is implemented for a ground coupled heat pump in heating/ system. The borehole heat exchangers – which are 150 m long - are filled with a mixture of water and ethilene glycol calledbrine. Metering and monitoring energy consumption is achieved for: heat pump, circulation pumps, additional electrical heating, hot air ventilation systems, control systems with sensors: analog and smart sensors. Instantaneous values are stored in a local computer.

  1. Comparison of Chemical Sensitivity of Fresh and Long-Stored Heat Resistant Neosartorya fischeri Environmental Isolates Using BIOLOG Phenotype MicroArray System.

    Directory of Open Access Journals (Sweden)

    Jacek Panek

    Full Text Available Spoilage of heat processed food and beverage by heat resistant fungi (HRF is a major problem for food industry in many countries. Neosartorya fischeri is the leading source of spoilage in thermally processed products. Its resistance to heat processing and toxigenicity makes studies about Neosartorya fischeri metabolism and chemical sensitivity essential. In this study chemical sensitivity of two environmental Neosartorya fischeri isolates were compared. One was isolated from canned apples in 1923 (DSM3700, the other from thermal processed strawberry product in 2012 (KC179765, used as long-stored and fresh isolate, respectively. The study was conducted using Biolog Phenotype MicroArray platforms of chemical sensitivity panel and traditional hole-plate method. The study allowed for obtaining data about Neosartorya fischeri growth inhibitors. The fresh isolate appeared to be much more resistant to chemical agents than the long-stored isolate. Based on phenotype microarray assay nitrogen compounds, toxic cations and membrane function compounds were the most effective in growth inhibition of N. fischeri isolates. According to the study zaragozic acid A, thallium(I acetate and sodium selenate were potent and promising N. fischeri oriented fungicides which was confirmed by both chemical sensitivity microplates panel and traditional hole-plate methods.

  2. Loop heat pipes - highly efficient heat-transfer devices for systems of sun heat supply

    Energy Technology Data Exchange (ETDEWEB)

    Maydanik, Yu. [Ural Branch of the Russian Academy of Sciences, Ekaterinburg (Russian Federation). Inst. of Thermophysics

    2004-07-01

    Loop heat pipes (LHPs) are hermetic heat-transfer devices operating on a closed evaporation-condensation cycle with the use of capillary pressure for pumping the working fluid [1]. In accordance with this, they possess all the main advantages of conventional heat pipes, but, as distinct from the latter, have a considerably higher heat-transfer capacity, especially when operating in the ''antigravity'' regime, when heat is transferred from above downwards. Besides, LHPs possess a higher functional versatility, are adaptable to different operating conditions and provide great scope for various design embodiments. This is achieved at the expense of both the original design of the device and the properties of the wick - a special capillary structure used for the creation of capillary pressure. The LHP schematic diagram is given in Fig. 1. The device contains an evaporator and a condenser - heat exchanger connected by means of smooth-walled pipe-lines with a relatively small diameter intended for separate motion of vapor and liquid. At present loop heat pipes are most extensively employed in thermoregulation systems of spacecrafts. Miniature LHPs are used for cooling electronics and computers. At the same time there exists a considerable potential of using these devices for the recovery of low-grade (waste) heat from different sources, and also in systems of sun heat supply. In the latter case LHPs may serve as an efficient heat-transfer link between a sun collector and a heat accumulator, which has a low thermal resistance and does not consume any additional energy for pumping the working fluid between them. (orig.)

  3. Match properties of heat transfer and coupled heat and mass transfer processes in air-conditioning system

    International Nuclear Information System (INIS)

    Zhang Tao; Liu Xiaohua; Zhang Lun; Jiang Yi

    2012-01-01

    Highlights: ► Investigates match properties of heat or mass transfer processes in HVAC system. ► Losses are caused by limited transfer ability, flow and parameter mismatching. ► Condition of flow matching is the same heat capacity of the fluids. ► Parameter matching is only reached along the saturation line in air–water system. ► Analytical solutions of heat and mass transfer resistance are derived. - Abstract: Sensible heat exchangers and coupled heat and mass transfer devices between humid air and water/desiccant are commonly used devices in air-conditioning systems. This paper focuses on the match properties of sensible heat transfer processes and coupled heat and mass transfer processes in an effort to understand the reasons for performance limitations in order to optimize system performance. Limited heat transfer capability and flow mismatching resulted in heat resistance of the sensible heat transfer process. Losses occurred during the heat and mass transfer processes due to limited transfer capability, flow mismatching, and parameter mismatching. Flow matching was achieved when the heat capacities of the fluids were identical, and parameter matching could only be reached along the saturation line in air–water systems or the iso-concentration line in air–desiccant systems. Analytical solutions of heat transfer resistance and mass transfer resistance were then derived. The heat and mass transfer process close to the saturation line is recommended, and heating sprayed water resulted in better humidification performance than heating inlet air in the air humidifier.

  4. Boise geothermal district heating system

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, P.J.

    1985-10-01

    This document describes the Boise geothermal district heating project from preliminary feasibility studies completed in 1979 to a fully operational system by 1983. The report includes information about the two local governments that participated in the project - the City of Boise, Idaho and the Boise Warm Springs Water District. It also discusses the federal funding sources; the financial studies; the feasibility studies conducted; the general system planning and design; design of detailed system components; the legal issues involved in production; geological analysis of the resource area; distribution and disposal; the program to market system services; and the methods of retrofitting buildings to use geothermal hot water for space heating. Technically this report describes the Boise City district heating system based on 170/sup 0/F water, a 4000 gpm production system, a 41,000 foot pipeline system, and system economies. Comparable data are also provided for the Boise Warm Springs Water District. 62 figs., 31 tabs.

  5. Nonstationary Heat Conduction in Atomic Systems

    Science.gov (United States)

    Singh, Amit K.

    reproduce the molecular dynamics results for a short-duration heat pulse where wavelike propagation of heat is observed thereby confirming the existence of second sound in argon. Implementations of the TPI method in MATLAB are available as part of the supplementary material. 2. The second major work of the thesis is to look into the following problem. The direct method for computing thermal conductivity in nonequilibrium molecular dynamics gives rise to an artificial Kapitza resistance at the interface between thermostatted and unthermostatted regions. This resistance, which depends on the system size and the thermostat parameters, creates discontinuous jumps in the temperature and heat flux across the interface and therefore affects the measured thermal conductivity. In this part, we propose a phenomenological relation for the Kapitza resistance that can be used to extract a value for the bulk thermal conductivity, which is independent of the system size and thermostat details. We also provide insight into the Kapitza phenomenon resulting from numerical thermostatting. 3. This constitutes our third part of the thesis. Silicon (001) surfaces in non-equilibrium molecular dynamics (NEMD) simulations above a critical transformation temperature undergo a reconstruction from the ideal diamond crystalline surface to a reconstructed structure involving the formation of rows of dimers along a direction. This process is accompanied by latent heat release that in NEMD simulations results in a dramatic increase in temperature of nanobeams that cross the transformation temperature as they are heated. To model this behavior, we propose a hybrid continuum partial differential equation for non-Fourier heat transfer coupled with a stochastic kinetic Monte Carlo (KMC) algorithm to account for latent heat release. An input to the method is the energy barrier for dimerization, which is computed separately using nudged elastic band calculations. The time-dependent temperature profiles along

  6. Heat recovery system series arrangements

    Energy Technology Data Exchange (ETDEWEB)

    Kauffman, Justin P.; Welch, Andrew M.; Dawson, Gregory R.; Minor, Eric N.

    2017-11-14

    The present disclosure is directed to heat recovery systems that employ two or more organic Rankine cycle (ORC) units disposed in series. According to certain embodiments, each ORC unit includes an evaporator that heats an organic working fluid, a turbine generator set that expands the working fluid to generate electricity, a condenser that cools the working fluid, and a pump that returns the working fluid to the evaporator. The heating fluid is directed through each evaporator to heat the working fluid circulating within each ORC unit, and the cooling fluid is directed through each condenser to cool the working fluid circulating within each ORC unit. The heating fluid and the cooling fluid flow through the ORC units in series in the same or opposite directions.

  7. Waste water heat recovery system

    OpenAIRE

    Markovi?, G.; Vranayov?, Z.; K?posztasov?, D.

    2016-01-01

    After heating and cooling, water heating is typically the second largest user of energy in the home. There are a lot of purposes and uses of hot water in buildings - showers, tubs, sinks, dishwashers and clothes washers etc. In most cases, these hot waste waters are discarded direct to sewer system. When we take into the account all of these purposes in every households, the wastewater retains a considerable portion of its initial energy ? energy that could be recovered and use...

  8. Corrosion Rate Monitoring in District Heating Systems

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Nielsen, Lars Vendelbo; Andersen, A.

    2005-01-01

    Quality control in district heating systems to keep uniform corrosion rates low and localized corrosion minimal is based on water quality control. Side-stream units equipped with carbon steel probes for online monitoring were mounted in district heating plants to investigate which techniques would...... be applicable, and if on-line monitoring could improve the quality control. Water quality monitoring was applied as well as corrosion rate monitoring with linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS), electrical resistance (ER) technique, mass loss and a crevice corrosion...... cell for localized corrosion risk estimation. Important variations in corrosion rate due to changes in make-up water quality were detected with the continuous monitoring provided by ER and crevice cell, while LPR gave unreliable corrosion rates. The acquisition time of two-three days for EIS...

  9. Heat pump having improved defrost system

    Science.gov (United States)

    Chen, F.C.; Mei, V.C.; Murphy, R.W.

    1998-12-08

    A heat pump system includes, in an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant: a compressor; an interior heat exchanger; an exterior heat exchanger; an accumulator; and means for heating the accumulator in order to defrost the exterior heat exchanger. 2 figs.

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

    International Nuclear Information System (INIS)

    El Moussaoui, Ahmed.

    1982-06-01

    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 [fr

  11. Methodology of heat transfer and flow resistance measurement for matrices of rotating regenerative heat exchangers

    Directory of Open Access Journals (Sweden)

    Butrymowicz Dariusz

    2016-09-01

    Full Text Available The theoretical basis for the indirect measurement approach of mean heat transfer coefficient for the packed bed based on the modified single blow technique was presented and discussed in the paper. The methodology of this measurement approach dedicated to the matrix of the rotating regenerative gas heater was discussed in detail. The testing stand consisted of a dedicated experimental tunnel with auxiliary equipment and a measurement system are presented. Selected experimental results are presented and discussed for selected types of matrices of regenerative air preheaters for the wide range of Reynolds number of gas. The agreement between the theoretically predicted and measured temperature profiles was demonstrated. The exemplary dimensionless relationships between Colburn heat transfer factor, Darcy flow resistance factor and Reynolds number were presented for the investigated matrices of the regenerative gas heater.

  12. Microbial profile, antibiotic sensitivity and heat resistance of bacterial ...

    African Journals Online (AJOL)

    Aim: This study was aimed at determining the prevalence, antibiotic resistance and heat resistance profile of bacterial isolates obtained from ready to eat roasted beef (suya) sold in Abuja, Nigeria. Methods and Results: Fifty samples of suya were purchased from different vendors within the Federal Capital Territory and ...

  13. Relaxation resistance of heat resisting alloys with cobalt

    International Nuclear Information System (INIS)

    Borzdyka, A.M.

    1977-01-01

    Relaxation resistance of refractory nickel-chromium alloys containing 5 to 14 % cobalt is under study. The tests involve the use of circular samples at 800 deg to 850 deg C. It is shown that an alloy containing 14% cobalt possesses the best relaxation resistance exceeding that of nickel-chromium alloys without any cobalt by a factor of 1.5 to 2. The relaxation resistance of an alloy with 5% cobalt can be increased by hardening at repeated loading

  14. Prototype solar-heating system

    Science.gov (United States)

    1978-01-01

    Complete air-collector system to meet needs of single-family dwelling is designed to operate in any region of United States except extreme north and south. Design can be scaled up or down to accomodate wide range of heating and hot-water requirements for single-family, multi-family, or commercial buildings without significantly changing design concept.

  15. Heat Pumping in Nanomechanical Systems

    Science.gov (United States)

    Chamon, Claudio; Mucciolo, Eduardo R.; Arrachea, Liliana; Capaz, Rodrigo B.

    2011-04-01

    We propose using a phonon pumping mechanism to transfer heat from a cold to a hot body using a propagating modulation of the medium connecting the two bodies. This phonon pump can cool nanomechanical systems without the need for active feedback. We compute the lowest temperature that this refrigerator can achieve.

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

    International Nuclear Information System (INIS)

    Sun Fangtian; Fu Lin; Zhang Shigang; Sun Jian

    2012-01-01

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

  17. Evaluating parameterizations of aerodynamic resistance to heat transfer using field measurements

    Directory of Open Access Journals (Sweden)

    Shaomin Liu

    2007-01-01

    Full Text Available Parameterizations of aerodynamic resistance to heat and water transfer have a significant impact on the accuracy of models of land – atmosphere interactions and of estimated surface fluxes using spectro-radiometric data collected from aircrafts and satellites. We have used measurements from an eddy correlation system to derive the aerodynamic resistance to heat transfer over a bare soil surface as well as over a maize canopy. Diurnal variations of aerodynamic resistance have been analyzed. The results showed that the diurnal variation of aerodynamic resistance during daytime (07:00 h–18:00 h was significant for both the bare soil surface and the maize canopy although the range of variation was limited. Based on the measurements made by the eddy correlation system, a comprehensive evaluation of eight popularly used parameterization schemes of aerodynamic resistance was carried out. The roughness length for heat transfer is a crucial parameter in the estimation of aerodynamic resistance to heat transfer and can neither be taken as a constant nor be neglected. Comparing with the measurements, the parameterizations by Choudhury et al. (1986, Viney (1991, Yang et al. (2001 and the modified forms of Verma et al. (1976 and Mahrt and Ek (1984 by inclusion of roughness length for heat transfer gave good agreements with the measurements, while the parameterizations by Hatfield et al. (1983 and Xie (1988 showed larger errors even though the roughness length for heat transfer has been taken into account.

  18. Heat resistant/radiation resistant cable and incore structure test device for FBR type reactor

    International Nuclear Information System (INIS)

    Tanimoto, Hajime; Shiono, Takeo; Sato, Yoshimi; Ito, Kazumi; Sudo, Shigeaki; Saito, Shin-ichi; Mitsui, Hisayasu.

    1995-01-01

    A heat resistant/radiation resistant coaxial cable of the present invention comprises an insulation layer, an outer conductor and a protection cover in this order on an inner conductor, in which the insulation layer comprises thermoplastic polyimide. In the same manner, a heat resistant/radiation resistant power cable has an insulation layer comprising thermoplastic polyimide on a conductor, and is provided with a protection cover comprising braid of alamide fibers at the outer circumference of the insulation layer. An incore structure test device for an FBR type reactor comprises the heat resistant/radiation resistant coaxial cable and/or the power cable. The thermoplastic polyimide can be extrusion molded, and has excellent radiation resistant by the extrusion, as well as has high dielectric withstand voltage, good flexibility and electric characteristics at high temperature. The incore structure test device for the FBR type reactor of the present invention comprising such a cable has excellent reliability and durability. (T.M.)

  19. Advanced regenerative heat recovery system

    Science.gov (United States)

    Prasad, A.; Jasti, J. K.

    1982-02-01

    A regenerative heat recovery system was designed and fabricated to deliver 1500 scfm preheated air to a maximum temperature of 1600 F. Since this system is operating at 2000 F, the internal parts were designed to be fabricated with ceramic materials. This system is also designed to be adaptable to an internal metallic structure to operate in the range of 1100 to 1500 F. A test facility was designed and fabricated to test this system. The test facility is equipped to impose a pressure differential of up to 27 inches of water column in between preheated air and flue gas lines for checking possible leakage through the seals. The preliminary tests conducted on the advanced regenerative heat recovery system indicate the thermal effectiveness in the range of 60% to 70%. Bench scale studies were conducted on various ceramic and gasket materials to identify the proper material to be used in high temperature applications. A market survey was conducted to identify the application areas for this heat recovery system. A cost/benefit analysis showed a payback period of less than one and a half years.

  20. Resistive Heating and Ion Drag in Saturn's Thermosphere

    Science.gov (United States)

    Vriesema, Jess William; Koskinen, Tommi; Yelle, Roger V.

    2017-10-01

    One of the most puzzling observations of the jovian planets is that the thermospheres of Jupiter, Saturn, Uranus and Neptune are all several times hotter than solar heating can account for (Strobel and Smith 1973; Yelle and Miller 2004; Muller-Wodarg et al. 2006). On Saturn, resistive heating appears sufficient to explain these temperatures in auroral regions, but the particular mechanism(s) responsible for heating the lower latitudes remains unclear. The most commonly proposed heating mechanisms are breaking gravity waves and auroral heating at the poles followed by redistribution of energy to mid-and low latitudes. Both of these energy sources are potentially important but also come with significant problems. Wave heating would have to be continuous and global to produce consistently elevated temperatures and the strong Coriolis forces coupled with polar ion drag appear to hinder redistribution of auroral energy (see Strobel et al. 2016 for review). Here we explore an alternative: wind-driven electrodynamics that can alter circulation and produce substantial heating outside of the auroral region. Smith (2013) showed this in-situ mechanism to be potentially significant in Jupiter’s thermosphere. We present new results from an axisymmetric, steady-state model that calculates resistive (Joule) heating rates through rigorous solutions of the electrodynamic equations for the coupled neutral atmosphere and ionosphere of Saturn. At present, we assume a dipole magnetic field and neglect any contributions from the magnetosphere. We use ion mixing ratios from the model of Kim et al. (2014) and the observed temperature-pressure profile from Koskinen et al. (2015) to calculate the generalized conductivity tensor as described by Koskinen et al. (2014). We calculate the current density under the assumption that it has no divergence and use it to calculate the resistive heating rates and ion drag. Our results suggest that resistive heating and ion drag at low latitudes likely

  1. Biomass universal district heating systems

    Science.gov (United States)

    Soltero, Victor Manuel; Rodríguez-Artacho, Salvador; Velázquez, Ramón; Chacartegui, Ricardo

    2017-11-01

    In mild climate regions Directive 27/2012 EU application for developing sustainable district heating networks in consolidated urban nucleus is a challenge. In Spain most of the municipalities above 5,000 inhabitants have a reliable natural gas network and individual heating systems at homes. In this work a new heating network paradigm is proposed, the biomass universal heating network in rural areas. This model involves all the economic, legal and technical aspects and interactions between the different agents of the systems: provider company, individual and collective end-users and local and regional administration. The continental region in Spain has 588 municipalities with a population above 1,500 inhabitants close to forest biomass with renewable use. In many of these cases the regulation identifies the ownership of the forest resources use. The universal heating networks are a great opportunity for energy saving of 2,000 GWh, avoiding 2.7 million tons of CO2 emissions and with a global annual savings for end users of 61.8 million of euros. The presented model is easily extrapolated to other small municipalities in Europe. The real application of the model is presented for three municipalities in different locations of Spain where Universal Heating Networks are under development. The analysis show the interest of the integrated model for the three cases with different structural agents and relationships between them. The use of sustainable forest resources, extracted and managed by local companies, strengths circular economy in the region with a potential global economic impact above 200 M€.

  2. Iron aluminide useful as electrical resistance heating elements

    Science.gov (United States)

    Sikka, Vinod K.; Deevi, Seetharama C.; Fleischhauer, Grier S.; Hajaligol, Mohammad R.; Lilly, Jr., A. Clifton

    1997-01-01

    The invention relates generally to aluminum containing iron-base alloys useful as electrical resistance heating elements. The aluminum containing iron-base alloys have improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The alloy has an entirely ferritic microstructure which is free of austenite and includes, in weight %, over 4% Al, .ltoreq.1% Cr and either .gtoreq.0.05% Zr or ZrO.sub.2 stringers extending perpendicular to an exposed surface of the heating element or .gtoreq.0.1% oxide dispersoid particles. The alloy can contain 14-32% Al, .ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Zr, .ltoreq.1% C, .ltoreq.0.1% B, .ltoreq.30% oxide dispersoid and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1% rare earth metal, .ltoreq.1% oxygen, .ltoreq.3% Cu, balance Fe.

  3. Research on Heat Exchange Process in Aircraft Air Conditioning System

    Science.gov (United States)

    Chichindaev, A. V.

    2017-11-01

    Using of heat-exchanger-condenser in the air conditioning system of the airplane Tu-204 (Boeing, Airbus, Superjet 100, MS-21, etc.) for cooling the compressed air by the cold air with negative temperature exiting the turbine results in a number of operational problems. Mainly it’s frosting of the heat exchange surface, which is the cause of live-section channels frosting, resistance increasing and airflow in the system decreasing. The purpose of this work is to analyse the known freeze-up-fighting methods for heat-exchanger-condenser, description of the features of anti-icing protection and offering solutions to this problem. For the problem of optimizing the design of heat exchangers in this work used generalized criterion that describes the ratio of thermal resistances of cold and hot sections, which include: the ratio of the initial values of heat transfer agents flow state; heat exchange surface finning coefficients; factors which describes the ratio of operating parameters and finning area. By controlling the ratio of the thermal resistances can be obtained the desired temperature of the heat exchange surface, which would prevent freezing. The work presents the results of a numerical study of the effect of different combinations of regime and geometrical factors changes on reduction of the heat-exchanger-condenser freezing surface area, including using of variable ratio of thermal resistances.

  4. Self-healing epoxy composite with heat-resistant healant.

    Science.gov (United States)

    Yuan, Yan Chao; Ye, Xiao Ji; Rong, Min Zhi; Zhang, Ming Qiu; Yang, Gui Cheng; Zhao, Jian Qing

    2011-11-01

    To provide self-healing epoxy composite with adequate heat resistance for high-performance application, we developed a novel microencapsulated epoxy/mercaptan healing agent. The key measure lies in usage of diglycidyl ether of bisphenol A (EPON 828) as the polymerizable component and 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30) as the catalyst. Because of the higher thermal stability of EPON 828 and lower volatility of DMP-30, the healing agent and the self-healing composite not only survive high-temperature curing and thermal exposure, but also offer satisfactory capability of autonomous properties restoration, as characterized by both fracture mechanics and fatigue tests. Especially when the operation temperature is not higher than 200 °C, the performance of the healing system is nearly independent of thermal history.

  5. Solar heating system at Security State Bank, Starkville, Mississippi

    Science.gov (United States)

    1980-01-01

    The 312 square feet of Solaron flat plate air collectors provide for 788 square feet of space heating, an estimated 55 percent of the heating load. Solar heated air is distributed to the 96 cubic foot steel cylinder, which contains two inch diameter rocks. An air handler unit moves the air over the collector and into the steel cylinder. Four motorized dampers and two gravity dampers are also part of the system. A Solaron controller which has sensors located at the collectors, rock storage, and at the return air, automatically controls the system. Auxiliary heating energy is provided by electric resistance duct heaters.

  6. Solar heating system at Security State Bank, Starkville, Mississippi

    Science.gov (United States)

    1980-08-01

    The 312 square feet of Solaron flat plate air collectors provide for 788 square feet of space heating, an estimated 55 percent of the heating load. Solar heated air is distributed to the 96 cubic foot steel cylinder, which contains two inch diameter rocks. An air handler unit moves the air over the collector and into the steel cylinder. Four motorized dampers and two gravity dampers are also part of the system. A Solaron controller which has sensors located at the collectors, rock storage, and at the return air, automatically controls the system. Auxiliary heating energy is provided by electric resistance duct heaters.

  7. Calcium bromide hydration for heat storage systems

    Directory of Open Access Journals (Sweden)

    Ai Niwa

    2015-12-01

    Full Text Available A chemical reaction is a common and simple way to produce heat for a heat storage system. The reaction produces heat energy without the use of electricity or fuel. The goal of this study was to develop a heat storage system for use in automobiles, which is able to provide heat rapidly via a hydration reaction. A heat storage system without an evaporator stores high-density heat and has a high heat output rate since the solid–liquid product that is formed is transferred as a heat medium to the object that requires heat. The exothermic heat produced from the solid–liquid reaction was measured, and the relationship between the equivalence ratio and the reaction heat was evaluated. The heat output and heat recovered by the heat storage system, which comprised a reaction vessel and a heat exchanger, were measured. We selected solid CaBr2 because it was the best metal halide for a hydration reaction and had a high heat yield from the dissolution reaction. With this system, we were able to achieve a heat recovery rate of 582 kJ/L-H2O. We found no degradation in the chemical composition of CaBr2 after it being recycled 100 times.

  8. Evaluation of Heat Checking and Washout of Heat Resistant Superalloys and Coatings for Die inserts

    Energy Technology Data Exchange (ETDEWEB)

    David Schwam; John F. Wallace; Yulong Zhu; Edward Courtright; Harold Adkins

    2005-01-30

    This project had two main objectives: (1) To design, fabricate and run a full size test for evaluating soldering and washout in die insert materials. This test utilizes the unique capabilities of the 350 Ton Squeeze Casting machine available in the Case Meal Casting Laboratory. Apply the test to evaluate resistance of die materials and coating, including heat resistant alloys to soldering and washout damage. (2) To evaluate materials and coatings, including heat resistant superalloys, for use as inserts in die casting of aluminum alloys.

  9. KSTAR RF heating system development

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, J. G.; Kim, S. K.; Hwang, C. K. (and others)

    2007-10-15

    Design, high-voltage test, and installation of 6 MW ICRF heating system for KSTAR is completed. The antenna demonstrated satisfactory standoff at high voltages up to 41 kV for 300 sec. The result indicates good power handling capabilities of the antenna as high as 10 MW/m2. This power density is equivalent to RF power coupling of 6 MW into a 4 {omega}/m target plasma, and is typical of advanced tokamak heating scenarios. In addition, vacuum feed through, DC break, and liquid stub developed for 300 sec operation are installed, as well as a 2 MW, 30-60MHz transmitter. The transmitter successfully produced output powers of 600 kW continuously, 1.5{approx}1.8 MW for 300 sec, and 2 MW for 100 msec or shorter pulses. A realtime control system based on DSP and EPICS is developed, installed, and tested on the ICRF system. Initial results from feasibility study indicate that the present antenna and the transmission lines could allow load-resilient operation on KSTAR. Until the KSTAR tokamak start to produce plasmas in 2008, however, hands-on operational experiences are obtained from participating in ICRF heating experiments at ASDEX and DIII-D tokamaks arranged through international cooperation.

  10. Heat-resistant hydrophobic-oleophobic coatings

    OpenAIRE

    Uyanik, Mehmet; Arpac, Ertugrul; Schmidt, Helmut K.; Akarsu, Murat; Sayilkan, Funda; Sayilkan, Hikmet

    2006-01-01

    Thermally and chemically durable hydrophobic oleophobic coatings, containing different ceramic particles such as SiO2, SiC, Al 2O3, which can be alternative instead of Teflon, have been developed and applied on the aluminum substrates by spin-coating method. Polyimides, which are high-thermal resistant heteroaromatic polymers, were synthesized, and fluor oligomers were added to these polymers to obtain hydrophobic-oleophobic properties. After coating, Al surface was subjected to Taber-abrasio...

  11. Improvement of sulfide corrosion resistance of nickel heat resisting alloys by means alloying

    International Nuclear Information System (INIS)

    Oryshkin, I.V.

    1999-01-01

    Paper describes the effect of the alloying elements (chromium, aluminium, titanium, molybdenum, tungsten, niobium, cobalt) on sulfide corrosion (SC) resistance of nickel base heat-resisting alloys during 30 h in 75% Na 2 SO 4 +25% NaCl molten sat under 900 deg C temperature. The obtained patterns are compared with the effect of the mentioned metals on the long-term strength. SC high resistance and the adequate level of heat resistance are ensured by a certain doping of a nickel base [ru

  12. Study on the heat-resistant EB curing composites

    International Nuclear Information System (INIS)

    Bao Jianwen; Li Yang; Li Fengmei

    2000-01-01

    There are many advantages in the EB-curing process of composites. Heat-resistant EB-curing composites could substitute for polyimide composites used in aeronautical engine. The effects of catalyst and dose on the cured resin were investigated. The heat-resistance of the resin cured by EB was evaluated by dynamic mechanical thermal analysis (DMTA). The experiment result shows that the mechanical property of the composites cured by EB could meet the needs of the aeronautical engine in 250degC. (author)

  13. Heating systems with PLC and frequency control

    Energy Technology Data Exchange (ETDEWEB)

    Abdallah, Salah; Abu-Mallouh, Riyad [Department of Mechanical and Industrial Engineering, Applied Science University, Amman 11931 (Jordan)

    2008-11-15

    In this work, medium capacity controlled heating system is designed and constructed. The programming method of control of heating process is achieved by means of integrated programmable logic controller (PLC) and frequency inverter (FI). The PLC main function is to determine the required temperatures levels and the related time intervals of the heating hold time in the furnace. FI is used to control the dynamic change of temperature between various operating points. The designed system shows the capability for full control of temperature from zero to maximum for any required range of time in case of increasing or decreasing the temperature. All variables of the system will be changed gradually until reaching their needed working points. An experimental study was performed to investigate the effect of tempering temperature and tempering time on hardness and fatigue resistance of 0.4% carbon steel. It was found that increasing tempering temperature above 550 C or tempering time decreases the hardness of the material. It was also found that there is a maximum number of cycles to which the specimen can survive what ever the applied load was. (author)

  14. Heating systems with PLC and frequency control

    International Nuclear Information System (INIS)

    Abdallah, Salah; Abu-Mallouh, Riyad

    2008-01-01

    In this work, medium capacity controlled heating system is designed and constructed. The programming method of control of heating process is achieved by means of integrated programmable logic controller (PLC) and frequency inverter (FI). The PLC main function is to determine the required temperatures levels and the related time intervals of the heating hold time in the furnace. FI is used to control the dynamic change of temperature between various operating points. The designed system shows the capability for full control of temperature from zero to maximum for any required range of time in case of increasing or decreasing the temperature. All variables of the system will be changed gradually until reaching their needed working points. An experimental study was performed to investigate the effect of tempering temperature and tempering time on hardness and fatigue resistance of 0.4% carbon steel. It was found that increasing tempering temperature above 550 deg. C or tempering time decreases the hardness of the material. It was also found that there is a maximum number of cycles to which the specimen can survive what ever the applied load was

  15. Compact seasonal PCM heat storage for solar heating systems

    DEFF Research Database (Denmark)

    Dannemand, Mark

    Space heating of buildings and preparation of domestic hot water accounts for a large part of the society’s energy consumption. Solar radiation is an abundant and renewable energy source which can be harvested by solar collectors and used to cover heating demands in the built environment....... The seasonal availability of solar energy does however not match with the heating demands in buildings which typically are large in winter periods when limited solar energy is available. Heat can be stored over a few days in water stores but continuous heat losses limits the storage periods. The possibility...... of storing heat from summer where solar energy is widely available to winter periods where the heating demands are large, allows for implementing more renewable energy in our energy system. The phase change material (PCM) sodium acetate trihydrate (SAT) melts at 58 °C. The melting process requires...

  16. Heat pumps in combined heat and power systems

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  17. Proceedings of heat transfer in space systems

    International Nuclear Information System (INIS)

    Chan, S.H.; Anderson, E.E.; Simoneau, R.J.; Chan, C.K.; Pepper, D.W.; Blackwell, B.F.

    1990-01-01

    This book contains the proceedings of heat transfer in space systems. Topics covered include: High-Power Electronics; Two-Phase Thermal Systems: Heat Exchangers; Arc Welding; Microgravity Thaw Experiment

  18. Heat Rejection Systems Utilizing Composites and Heat Pipes: Design and Performance Testing

    Science.gov (United States)

    Jaworske, Donald A.; Beach, Duane E.; Sanzi, James L.

    2007-01-01

    Polymer matrix composites offer the promise of reducing the mass and increasing the performance of future heat rejection systems. With lifetimes for heat rejection systems reaching a decade or more in a micrometeoroid environment, use of multiple heat pipes for fault tolerant design is compelling. The combination of polymer matrix composites and heat pipes is of particular interest for heat rejection systems operating on the lunar surface. A technology development effort is under way to study the performance of two radiator demonstration units manufactured with different polymer matrix composite face sheet resin and bonding adhesives, along with different titanium-water heat pipe designs. Common to the two radiator demonstration units is the use of high thermal conductivity fibers in the face sheets and high thermal conductivity graphite saddles within a light weight aluminum honeycomb core. Testing of the radiator demonstration units included thermal vacuum exposure and thermal vacuum exposure with a simulated heat pipe failure. Steady state performance data were obtained at different operating temperatures to identify heat transfer and thermal resistance characteristics. Heat pipe failure was simulated by removing the input power from an individual heat pipe in order to identify the diminished performance characteristics of the entire panel after a micrometeoroid strike. Freeze-thaw performance was also of interest. This paper presents a summary of the two radiator demonstration units manufactured to support this technology development effort along with the thermal performance characteristics obtained to date. Future work will also be discussed.

  19. 14 CFR 27.859 - Heating systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Heating systems. 27.859 Section 27.859... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Fire Protection § 27.859 Heating systems. (a) General. For each heating system that involves the passage of cabin air over, or close to, the exhaust...

  20. Two distinct groups within the Bacillus subtilis group display significantly different spore heat resistance properties.

    Science.gov (United States)

    Berendsen, Erwin M; Zwietering, Marcel H; Kuipers, Oscar P; Wells-Bennik, Marjon H J

    2015-02-01

    The survival of bacterial spores after heat treatment and the subsequent germination and outgrowth in a food product can lead to spoilage of the food product and economical losses. Prediction of time-temperature conditions that lead to sufficient inactivation requires access to detailed spore thermal inactivation kinetics of relevant model strains. In this study, the thermal inactivation kinetics of spores of fourteen strains belonging to the Bacillus subtilis group were determined in detail, using both batch heating in capillary tubes and continuous flow heating in a micro heater. The inactivation data were fitted using a log linear model. Based on the spore heat resistance data, two distinct groups (p subtilis group could be identified. One group of strains had spores with an average D120 °C of 0.33 s, while the spores of the other group displayed significantly higher heat resistances, with an average D120 °C of 45.7 s. When comparing spore inactivation data obtained using batch- and continuous flow heating, the z-values were significantly different, hence extrapolation from one system to the other was not justified. This study clearly shows that heat resistances of spores from different strains in the B. subtilis group can vary greatly. Strains can be separated into two groups, to which different spore heat inactivation kinetics apply. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Comparison of Direct Solar Energy to Resistance Heating for Carbothermal Reduction of Regolith

    Science.gov (United States)

    Muscatello, Anthony C.; Gustafson, Robert J.

    2011-01-01

    A comparison of two methods of delivering thermal energy to regolith for the carbo thermal reduction process has been performed. The comparison concludes that electrical resistance heating is superior to direct solar energy via solar concentrators for the following reasons: (1) the resistance heating method can process approximately 12 times as much regolith using the same amount of thermal energy as the direct solar energy method because of superior thermal insulation; (2) the resistance heating method is more adaptable to nearer-term robotic exploration precursor missions because it does not require a solar concentrator system; (3) crucible-based methods are more easily adapted to separation of iron metal and glass by-products than direct solar energy because the melt can be poured directly after processing instead of being remelted; and (4) even with projected improvements in the mass of solar concentrators, projected photovoltaic system masses are expected to be even lower.

  2. Fast temperature programming in gas chromatography using resistive heating

    NARCIS (Netherlands)

    Dallüge, J.; Ou-Aissa, R.; Vreuls, J.J.; Brinkman, U.A.T.; Veraart, J.R.

    1999-01-01

    The features of a resistive-heated capillary column for fast temperature-programmed gas chromatography (GC) have been evaluated. Experiments were carried out using a commercial available EZ Flash GC, an assembly which can be used to upgrade existing gas chromatographs. The capillary column is placed

  3. Fuzzy comprehensive evaluation of district heating systems

    International Nuclear Information System (INIS)

    Wei Bing; Wang Songling; Li Li

    2010-01-01

    Selecting the optimal type of district heating (DH) system is of great importance because different heating systems have different levels of efficiency, which will impact the system economics, environment and energy use. In this study, seven DH systems were analysed and evaluated by the fuzzy comprehensive evaluation method. The dimensionless number-goodness was introduced into the calculation, the economics, environment and energy technology factors were considered synthetically, and the final goodness values were obtained. The results show that if only one of the economics, environment or energy technology factors are considered, different heating systems have different goodness values. When all three factors were taken into account, the final ranking of goodness values was: combined heating and power>gas-fired boiler>water-source heat pump>coal-fired boiler>ground-source heat pump>solar-energy heat pump>oil-fired boiler. The combined heating and power system is the best choice from all seven systems; the gas-fired boiler system is the best of the three boiler systems for heating purpose; and the water-source heat pump is the best of the three heat pump systems for heating and cooling.

  4. Study on modeling of resist heating effect correction in EB mask writer EBM-9000

    Science.gov (United States)

    Nomura, Haruyuki; Kamikubo, Takashi; Suganuma, Mizuna; Kato, Yasuo; Yashima, Jun; Nakayamada, Noriaki; Anze, Hirohito; Ogasawara, Munehiro

    2015-07-01

    Resist heating effect which is caused in electron beam lithography by rise in substrate temperature of a few tens or hundreds of degrees changes resist sensitivity and leads to degradation of local critical dimension uniformity (LCDU). Increasing writing pass count and reducing dose per pass is one way to avoid the resist heating effect, but it worsens writing throughput. As an alternative way, NuFlare Technology is developing a heating effect correction system which corrects CD deviation induced by resist heating effect and mitigates LCDU degradation even in high dose per pass conditions. Our developing correction model is based on a dose modulation method. Therefore, a kind of conversion equation to modify the dose corresponding to CD change by temperature rise is necessary. For this purpose, a CD variation model depending on local pattern density was introduced and its validity was confirmed by experiments and temperature simulations. And then the dose modulation rate which is a parameter to be used in the heating effect correction system was defined as ideally irrelevant to the local pattern density, and the actual values were also determined with the experimental results for several resist types. The accuracy of the heating effect correction was also discussed. Even when deviations depending on the pattern density slightly remains in the dose modulation rates (i.e., not ideal in actual), the estimated residual errors in the correction are sufficiently small and acceptable for practical 2 pass writing with the constant dose modulation rates. In these results, it is demonstrated that the CD variation model is effective for the heating effect correction system.

  5. Microbial Heat Recovery Cell (MHRC) System Concept

    Energy Technology Data Exchange (ETDEWEB)

    None

    2017-09-01

    This factsheet describes a project that aimed to develop a microbial heat recovery cell (MHRC) system that combines a microbial reverse electrodialysis technology with waste heat recovery to convert industrial effluents into electricity and hydrogen.

  6. The locus of heat resistance (LHR) mediates heat resistance in Salmonella enterica, Escherichia coli and Enterobacter cloacae.

    Science.gov (United States)

    Mercer, Ryan G; Walker, Brian D; Yang, Xianqin; McMullen, Lynn M; Gänzle, Michael G

    2017-06-01

    Enterobacteriaceae comprise food spoilage organisms as well as food-borne pathogens including Escherichia coli. Heat resistance in E. coli was attributed to a genomic island called the locus of heat resistance (LHR). This genomic island is also present in several other genera of Enterobacteriaceae, but its function in the enteric pathogens Salmonella enterica and Enterobacter cloacae is unknown. This study aimed to determine the frequency of the LHR in food isolates of E. coli, and its influence on heat resistance in S. enterica and Enterobacter spp. Cell counts of LHR-positive strains of E. coli, S. enterica and E. cloacae were reduced by less than 1, 1, and 4 log (cfu/mL), respectively, after exposure to 60 °C for 5 min, while cell counts of LHR-negative strains of the same species were reduced by more than 7 log (cfu/mL). Introducing an exogenous copy of the LHR into heat-sensitive enteropathogenic E. coli and S. enterica increased heat resistance to a level that was comparable to LHR-positive wild type strains. Cell counts of LHR-positive S. enterica were reduced by less than 1 log(cfu/mL) after heating to 60 °C for 5 min. Survival of LHR-positive strains was improved by increasing the NaCl concentration from 0 to 4%. Cell counts of LHR-positive strains of E. coli and S. enterica were reduced by less than 2 log (cfu/g) in ground beef patties cooked to an internal core temperature of 71 °C. This study indicates that LHR-positive Enterobacteriaceae pose a risk to food safety. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. KTA 625 alloy tube with excellent corrosion resistance and heat resistance

    International Nuclear Information System (INIS)

    Fujiwara, Kazuo; Kadonaga, Toshiki; Kikuma, Seiji.

    1982-01-01

    The problems when seamless tubes are produced by using nickel base 625 alloy (61Ni-22Cr-9Mo-Cb) which is known as a corrosion resistant and heat resistant alloyF were examined, and the confirmation experiment was carried out on its corrosion resistance and heat resistance. Various difficulties have been experienced in the tube making owing to the characteristics due to the chemical composition, but they were able to be solved by the repeated experiments. As for the characteristics of the product, the corrosion resistance was excellent particularly in the environment containing high temperature, high concentration chloride, and also the heat resistance was excellent in the wide temperature range from normal temperature to 1000 deg C. From these facts, the wide fields of application are expected for these alloy tubes, including the evaporation and concentration equipment for radioactive wastes in atomic energy field. Expecting the increase of demand hereafter, Kobe Steel Ltd. examined the problems when seamless tubes are produced from the 625 alloy by Ugine Sejournet process. The aptitude for tube production such as the chemical composition, production process and the product characteristics, the corrosion resistance against chloride, hydrogen sulfide, polythionic and other acids,F the high temperature strength and oxidation resistance are reported. (Kako, I.)

  8. Indoor temperatures for calculating room heat loss and heating capacity of radiant heating systems combined with mechanical ventilation systems

    DEFF Research Database (Denmark)

    Wu, Xiaozhou; Olesen, Bjarne W.; Fang, Lei

    2016-01-01

    In this study, a typical office room with a radiant heating system and a mechanical ventilation system was selected as the research subject. Indoor temperature formulas for calculating the room heat loss (including transmission heat loss and ventilation heat loss) and heating capacity of the hybrid...... for calculating ventilation heat loss and heating capacity of radiant heating systems combined with mechanical ventilation systems. (C) 2015 Elsevier B.V. All rights reserved....... change rates on the indoor temperatures were performed using the proposed model. When heated surface temperatures and air change rates were from 21.0 to 29.0 degrees C and from 0.5 to 4.0 h-1, the indoor temperatures for calculating the transmission heat loss and ventilation heat loss were between 20...

  9. Heat-resistant bacterial phytase in broiler pelleted diets

    Directory of Open Access Journals (Sweden)

    TC de F Carlos

    2015-03-01

    Full Text Available The objective of the study was to evaluate the effects of a heat-resistant bacterial phytase added to pelleted diets on mineral digestibility, live performance, carcass traits, and bone quality of broilers. Three treatments were evaluated: Positive control; negative control, with 0.10 points reduction in calcium level and 0.15 points reduction in available phosphorus level; and negative control + phytase at 500 FTU/kg. Mineral digestibility and bone quality results demonstrated that the evaluated phytase resisted pelleting as it increased the utilization of the minerals present in the diet.

  10. Intensification of Convective Heat Transfer in Heating Device of Mobile Heating System with BH-Heat Generator

    Directory of Open Access Journals (Sweden)

    N. A. Nesenchuk

    2013-01-01

    Full Text Available Directions pertaining to intensification of convective heat transfer in a soft heating device have been experimentally investigated  in the paper and the most efficient one has been selected that is creation of artificial roughness on the device surface. The considered heating device for a heat supply system of a mobile object has been made of soft polymer material (polyvinyl chloride. Following  evaluation results of  heat exchange intensification a criteria equation has been obtained for calculation of external heat transfer with due account of heat transfer intensification.

  11. Heat resistance of Lactobacillus spp. isolated from Cheddar cheese.

    Science.gov (United States)

    Jordan, K N; Cogan, T M

    1999-08-01

    Mesophilic Lactobacillus spp. are the dominant organisms in mature Cheddar cheese. The heat resistance of broth grown cultures of Lactobacillus plantarum DPC1919 at temperatures between 50 and 57.5 degrees C, Lact. plantarum DPC2102 at temperatures between 48 and 56 degrees C and Lact. paracasei DPC2103 at temperatures between 50 and 67.5 degrees C was determined. The z-values for Lact. plantarum DPC1919, Lact. Plantarum DPC2102 and Lact. paracasei DPC2103 were 6.7 degrees C, 6.2 degrees C and 5.3 degrees C, respectively. Lactobacillus paracasei DPC2103 showed evidence of injury and recovery, especially at higher temperatures. Milk grown cultures of strains DPC2102 and DPC2103 showed greater heat resistance than broth grown cultures, tailing of the death curves and a nonlinear z-curve. Of the three strains, Lact. paracasei DPC2103 had the potential to survive pasteurization temperatures, whether grown in milk or broth.

  12. Residential CO{sub 2} heat pump system for combined space heating and hot water heating

    Energy Technology Data Exchange (ETDEWEB)

    Stene, Joern

    2004-02-01

    Carbon dioxide (CO{sub 2}, R-744) has been identified as a promising alternative to conventional working fluids in a number of applications due to its favourable environmental and thermophysical properties. Previous work on residential CO{sub 2} heat pumps has been dealing with systems for either space heating or hot water heating, and it was therefore considered interesting to carry out a theoretical and experimental study of residential CO{sub 2} heat pump systems for combined space heating and hot water heating - o-called integrated CO{sub 2} heat pump systems. The scope of this thesis is limited to brine-to-water and water-to-water heat pumps connected to low-temperature hydronic space heating systems. The main conclusions are: (1) Under certain conditions residential CO{sub 2} heat pump systems for combined space heating and hot water heating may achieve the same or higher seasonal performance factor (SPF) than the most energy efficient state-of-the-art brine-to-water heat pumps. (2) In contrary to conventional heat pump systems for combined space heating and DHW heating, the integrated CO{sub 2} heat pump system achieves the highest COP in the combined heating mode and the DHW heating mode, and the lowest COP in the space heating mode. Hence, the larger the annual DHW heating demand, the higher the SPF of the integrated CO{sub 2} heat pump system. (3) The lower the return temperature in the space heating system and the lower the DHW storage temperature, the higher the COP of the integrated CO{sub 2} heat pump. A low return temperature in the space heating system also results in a moderate DHW heating capacity ratio, which means that a relatively large part of the annual space heating demand can be covered by operation in the combined heating mode, where the COP is considerably higher than in the space heating mode. (4) During operation in the combined heating mode and the DHW heating mode, the COP of the integrated CO{sub 2} heat pump is heavily influenced by

  13. Waste Heat Recapture from Supermarket Refrigeration Systems

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Brian A [ORNL

    2011-11-01

    The objective of this project was to determine the potential energy savings associated with improved utilization of waste heat from supermarket refrigeration systems. Existing and advanced strategies for waste heat recovery in supermarkets were analyzed, including options from advanced sources such as combined heat and power (CHP), micro-turbines and fuel cells.

  14. Heat Resisting Metals for Gas Turbine Parts N-102

    Science.gov (United States)

    1943-04-12

    stook later supplied by • •’••"’." %••*•’. ’ ,./v. TABU 8. -29- D1TA PROM STHESS-BUPTTOJ TESTS AT 1800*F. Material Alloy limber Condition...properties of the three heat-resisting alloys Tirnlom 16-25-6, Gamma ColumMum, and S495 alloys. Bar stook of the latter two alloys Is available

  15. Thermoelectric System Absorbing Waste Heat from a Steel Ladle

    Science.gov (United States)

    Lu, Baiyi; Meng, Xiangning; Zhu, Miaoyong; Suzuki, Ryosuke O.

    2018-01-01

    China's iron and steel industry has made great progress in energy savings and emission reductions with the application of many waste heat recovery technologies. However, most of the medium and low temperature waste heat and radiant waste heat has not been effectively utilized. This paper proposes a thermoelectric system that generates electricity by absorbing the radiant heat from the surface of steel ladles in a steel plant. The thermoelectric behavior of modules in this system is analyzed by a numerical simulation method. The effects of external resistance and module structure on thermoelectric performance are also discussed in the temperature range of the wall surface of a steel ladle. The results show that the wall temperature has a significant influence on the thermoelectric behavior of the module, so its uniformity and stability should be considered in practical application. The ratio of the optimum external resistance to the internal resistance of the thermoelectric module is in the range of 1.6-2.0, which indicates the importance of external load optimization for a given thermoelectric system. In addition, the output power and the conversion efficiency of the module can be significantly improved by increasing the length of the thermoelectric legs and adopting a double-layer structure. Finally, through the optimization of external resistance and structure, the power output can reach 83-304 W/m2. This system is shown to be a promising approach for energy recovery.

  16. Corrosion resistance of heat exchange equipment in hydrotreating Orenburg Condensate

    International Nuclear Information System (INIS)

    Teslya, B.M.; Burlov, V.V.; Parputs, I.V.; Parputs, T.P.

    1986-01-01

    The authors study the corrosion resistance of materials of construction and select appropriate materials for the fabrication of heat exchange equipment that will be serviceable under hydrotreating conditions. This paper discusses the Orenburg condensate hydrotreating unit which has been shut down repeatedly for repair because of corrosion damage to components of heat exchangers in the reactor section: tube bundles (08Kh18N10T steel), corrugated compensators (12Kh18N10T steel), and pins of the floating heads (37Kh13N8G8MFB steel). The authors recommend that the tube bundles and the compensators in heat exchangers in the reaction section should be fabricated of 08Kh21N6M2T or 10Kh17N13M2T steel. The pins have been replaced by new pins made of 10Kh17N13 X M2T steel, increasing the service life from 6-12 months to 2 years

  17. 1.9 K Heat Inleak and Resistive Heating Measurements on LHC Cryomagnets

    CERN Document Server

    Ferlin, G; Tavian, L; Wagner, U

    2010-01-01

    The superconducting magnets of the Large Hadron Collider (LHC) distributed over eight sectors of 3.3-km long are cooled at 1.9 K in pressurized superfluid helium. During the commissioning campaign of the sectors in 2008, cold standby periods at nominal operating temperature have allowed to measure the overall static heat inleaks reaching the magnet cold masses at 1.9 K by enthalpy balance in steady-state operation. In addition, during electrical powering of the different magnet circuits, helium II calorimetry based on precision thermometry has been implemented to assess with an accuracy of 100 mW/m the additional heat loads due to resistive heating and to detect possible abnormal heat dissipation during powering. This paper describes the method applied to perform these measurements, compares the results with the expected specified values and discusses the impact of the measured values on cryo-plant tuning and operational margins.

  18. Control challenges in domestic heating systems

    DEFF Research Database (Denmark)

    Thybo, Honglian; Larsen, Lars F. S.; Weitzmann, Peter

    2007-01-01

    The objective of this paper is to analyze domestic heating applications and identify unfavorable building constructions and control challenges to be addressed by high performance heating control systems. Heating of domestic houses use a large amount of the total energy consumption in Scandinavia....... Hence the potential of reducing energy consumption by applying high performance control is vast. Indoor climate issues are becoming more in focus, which also leads to a demand for high performance heating systems. The paper presents an analysis of how the building elements of today's domestic houses...... with water based floor heating affect the control challenge. The analysis is documented with simulation results....

  19. Hybrid district heating system with heat supply from nuclear source

    International Nuclear Information System (INIS)

    Havelka, Z.; Petrovsky, I.

    1987-01-01

    Several designs are described of heat supply from large remote power sources (e.g., WWER-1000 nuclear power plants with a 1000 MW turbine) to localities where mainly steam distribution networks have been built but only some or none networks for hot water distribution. The benefits of the designs stem from the fact that they do not require the conversion of the local steam distribution system to a hot water system. They are based on heat supply from the nuclear power plant to the consumer area in hot water of a temperature of 150 degC to 200 degC. Part of the hot water heat will be used for the production of low-pressure steam which will be compressed using heat pumps (steam compressors) to achieve the desired steam distribution network specifications. Water of lower temperature can be used in the hot water network. The hot water feeder forms an automatic pressure safety barrier in heat supply of heating or technological steam from a nuclear installation. (Z.M.). 5 figs., 9 refs

  20. Advances in Solar Heating and Cooling Systems

    Science.gov (United States)

    Ward, Dan S.

    1976-01-01

    Reports on technological advancements in the fields of solar collectors, thermal storage systems, and solar heating and cooling systems. Diagrams aid in the understanding of the thermodynamics of the systems. (CP)

  1. Correction of the heat loss method for calculating clothing real evaporative resistance.

    Science.gov (United States)

    Wang, Faming; Zhang, Chengjiao; Lu, Yehu

    2015-08-01

    In the so-called isothermal condition (i.e., Tair [air temperature]=Tmanikin [manikin temperature]=Tr [radiant temperature]), the actual energy used for moisture evaporation detected by most sweating manikins was underestimated due to the uncontrolled fabric 'skin' temperature Tsk,f (i.e., Tsk,fclothing real evaporative resistance. In this study, correction of the real evaporative heat loss from the wet fabric 'skin'-clothing system was proposed and experimentally validated on a 'Newton' sweating manikin. The real evaporative resistance of five clothing ensembles and the nude fabric 'skin' calculated by the corrected heat loss method was also reported and compared with that by the mass loss method. Results revealed that, depending on the types of tested clothing, different amounts of heat were drawn from the ambient environment. In general, a greater amount of heat was drawn from the ambient environment by the wet fabric 'skin'-clothing system in lower thermal insulation clothing than that in higher insulation clothing. There were no significant differences between clothing real evaporative resistances calculated by the corrected heat loss method and those by the mass loss method. It was therefore concluded that the correction method proposed in this study has been successfully validated. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Improving Process Heating System Performance v3

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-04-11

    Improving Process Heating System Performance: A Sourcebook for Industry is a development of the U.S. Department of Energy (DOE) Advanced Manufacturing Office (AMO) and the Industrial Heating Equipment Association (IHEA). The AMO and IHEA undertook this project as part of an series of sourcebook publications developed by AMO on energy-consuming industrial systems, and opportunities to improve performance. Other topics in this series include compressed air systems, pumping systems, fan systems, steam systems, and motors and drives

  3. Proposal for a district heat supply system

    International Nuclear Information System (INIS)

    Alefeld, G.

    1976-01-01

    A district heating scheme is proposed which makes it possible to use the waste heat from power stations for the supply of households and industry. The heat is stored by evaporation of ammonia salts or liquids with dissolved salts. Both substances are transported on existing rail- or waterways to heating stations near the consumers, and the heat recovered by reaction of the two components. Then the product of reaction is transported back to the power stations, and reactivated by heat again. Based on a cost estimation, it can be shown that the proposed heat transport with heat trains or ships, at distances up to 100 km, results in heat costs which are to-day already below that of heat from fuel oil. The investment required for the heat transport system is unusually low due to the use of transport ways which already exist. The district heating system is not only favourable in respect of the environment, but actually reduces its present strain, both at the consumer and at the power stations. The technical advantages of the suggested concept, especially the possibility of introducing it in stages, are discussed. The consequences for the national economy regarding the safety of supply and the trade balance, as well as for the public transport undertakings, are obvious, and therefore not included in the paper. (orig.) [de

  4. Large Efficient Intelligent Heating Relay Station System

    Science.gov (United States)

    Wu, C. Z.; Wei, X. G.; Wu, M. Q.

    2017-12-01

    The design of large efficient intelligent heating relay station system aims at the improvement of the existing heating system in our country, such as low heating efficiency, waste of energy and serious pollution, and the control still depends on the artificial problem. In this design, we first improve the existing plate heat exchanger. Secondly, the ATM89C51 is used to control the whole system and realize the intelligent control. The detection part is using the PT100 temperature sensor, pressure sensor, turbine flowmeter, heating temperature, detection of user end liquid flow, hydraulic, and real-time feedback, feedback signal to the microcontroller through the heating for users to adjust, realize the whole system more efficient, intelligent and energy-saving.

  5. Evaluation of Excess Heat Utilization in District Heating Systems by Implementing Levelized Cost of Excess Heat

    Directory of Open Access Journals (Sweden)

    Borna Doračić

    2018-03-01

    Full Text Available District heating plays a key role in achieving high primary energy savings and the reduction of the overall environmental impact of the energy sector. This was recently recognized by the European Commission, which emphasizes the importance of these systems, especially when integrated with renewable energy sources, like solar, biomass, geothermal, etc. On the other hand, high amounts of heat are currently being wasted in the industry sector, which causes low energy efficiency of these processes. This excess heat can be utilized and transported to the final customer by a distribution network. The main goal of this research was to calculate the potential for excess heat utilization in district heating systems by implementing the levelized cost of excess heat method. Additionally, this paper proves the economic and environmental benefits of switching from individual heating solutions to a district heating system. This was done by using the QGIS software. The variation of different relevant parameters was taken into account in the sensitivity analysis. Therefore, the final result was the determination of the maximum potential distance of the excess heat source from the demand, for different available heat supplies, costs of pipes, and excess heat prices.

  6. Radiant Heating and Cooling Systems. Part one

    DEFF Research Database (Denmark)

    Kim, Kwan Woo; Olesen, Bjarne W.

    2015-01-01

    The use of radiant heating systems has several thousand years of history.1,2 The early stage of radiant system application was for heating purposes, where hot air from flue gas (cooking, fires) was circulated under floors or in walls. After the introduction of plastic piping water-based radiant...... heating and cooling with pipes embedded in room surfaces (floor, wall, and ceiling), the application increased significantly worldwide. Earlier application of radiant heating systems was mainly for residential buildings because of its comfort and free use of floor space without any obstruction from...

  7. Heat exchanger with auxiliary cooling system

    Science.gov (United States)

    Coleman, John H.

    1980-01-01

    A heat exchanger with an auxiliary cooling system capable of cooling a nuclear reactor should the normal cooling mechanism become inoperable. A cooling coil is disposed around vertical heat transfer tubes that carry secondary coolant therethrough and is located in a downward flow of primary coolant that passes in heat transfer relationship with both the cooling coil and the vertical heat transfer tubes. A third coolant is pumped through the cooling coil which absorbs heat from the primary coolant which increases the downward flow of the primary coolant thereby increasing the natural circulation of the primary coolant through the nuclear reactor.

  8. Martensitic/ferritic super heat-resistant 650 C steels

    Energy Technology Data Exchange (ETDEWEB)

    Agamennone, R.; Blum, W. [IWW-LS1, Univ. Erlangen-Nuernberg, Erlangen (Germany); Berger, C.; Granacher, J.; Scholz, A.; Wang, Y. [IfW, TU Darmstadt, Darmstadt (Germany); Ehlers, J.; Ennis, P.J.; Quadakkers, J.W.; Singheiser, L. [IWV2, Forschungszentrum Juelich GmbH, Juelich (Germany); Inden, G.; Knezevic, V.; Sauthoff, G.; Vilk, J. [Max-Planck-Inst. fuer Eisenforschung GmbH, Duesseldorf (Germany)

    2002-07-01

    World-wide demand for higher steam parameters of ultra super critical (USC) Power Plants has led to developments of new materials with improved high-temperature properties. A new project aims at new ferritic creep-resistant steels for application at 650 C and 300 bar. The critical issues are improvement of long-term creep strength as well as oxidation and corrosion resistance. The aim of the present research is to design new super heat-resistant martensitic/ferritic 9-12%Cr steels using basic principles and concepts of physical metallurgy, to test and optimise model alloys and to investigate and clarify their behaviour under long-term creep conditions with emphasis on microstructural stability and corrosion resistance. Model alloys have been designed, produced and tested with respect to deformation and corrosion. The design of model alloys has been supported by theoretical simulations and transmission electron microscopy investigations. First results for various modified 12%Cr model steels are reported, which indicate a high potential for reaching sufficient creep and corrosion resistance at 650 C. The work with further optimisation of composition and microstructure is in progress. (orig.)

  9. Rankine cycle waste heat recovery system

    Science.gov (United States)

    Ernst, Timothy C.; Nelson, Christopher R.

    2015-09-22

    A waste heat recovery (WHR) system connects a working fluid to fluid passages formed in an engine block and/or a cylinder head of an internal combustion engine, forming an engine heat exchanger. The fluid passages are formed near high temperature areas of the engine, subjecting the working fluid to sufficient heat energy to vaporize the working fluid while the working fluid advantageously cools the engine block and/or cylinder head, improving fuel efficiency. The location of the engine heat exchanger downstream from an EGR boiler and upstream from an exhaust heat exchanger provides an optimal position of the engine heat exchanger with respect to the thermodynamic cycle of the WHR system, giving priority to cooling of EGR gas. The configuration of valves in the WHR system provides the ability to select a plurality of parallel flow paths for optimal operation.

  10. Radiant Heating and Cooling Systems. Part two

    DEFF Research Database (Denmark)

    Kim, Kwan Woo; Olesen, Bjarne W.

    2015-01-01

    Control of the heating and cooling system needs to be able to maintain the indoor temperatures within the comfort range under the varying internal loads and external climates. To maintain a stable thermal environment, the control system needs to maintain the balance between the heat gain...

  11. Basics of Solar Heating & Hot Water Systems.

    Science.gov (United States)

    American Inst. of Architects, Washington, DC.

    In presenting the basics of solar heating and hot water systems, this publication is organized from the general to the specific. It begins by presenting functional and operational descriptions of solar heating and domestic hot water systems, outlining the basic concepts and terminology. This is followed by a description of solar energy utilization…

  12. Standard monitoring system for domestic heat pumps

    NARCIS (Netherlands)

    Geelen, C.P.J.M.; Oostendorp, P.A.

    1999-01-01

    In the years to come many domestic heat pump systems are to be installed in the Netherlands. The Dutch agency for energy and environment, NOVEM, and the association of energy utility companies, EnergieNed, give high priority to the monitoring of heat pump systems. The results of the projects,

  13. Systemic resistance induced by rhizosphere bacteria

    NARCIS (Netherlands)

    Loon, L.C. van; Bakker, P.A.H.M.; Pieterse, C.M.J.

    1998-01-01

    Nonpathogenic rhizobacteria can induce a systemic resistance in plants that is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). Rhizobacteria-mediated induced systemic resistance (ISR) has been demonstrated against fungi, bacteria, and viruses in Arabidopsis, bean,

  14. Challenges and advances in systems biology analysis of Bacillus spore physiology; molecular differences between an extreme heat resistant spore forming Bacillus subtilis food isolate and a laboratory strain

    NARCIS (Netherlands)

    Brul, Stanley; van Beilen, Johan; Caspers, Martien P M; O'Brien, Andrea; de Koster, Chris; Oomes, Suus; Smelt, Jan; Kort, Remco; Ter Beek, Alex

    Bacterial spore formers are prime organisms of concern in the food industry. Spores from the genus Bacillus are extremely stress resistant, most notably exemplified by high thermotolerance. This sometimes allows surviving spores to germinate and grow out to vegetative cells causing food spoilage and

  15. Challenges and advances in systems biology analysis of Bacillus spore physiology; molecular differences between an extreme heat resistant spore forming Bacillus subtilis food isolate and a laboratory strain

    NARCIS (Netherlands)

    Brul, S.; van Beilen, J.; Caspers, M.; O'Brien, A.; de Koster, C.; Oomes, S.; Smelt, J.; Kort, R.; ter Beek, A.

    2011-01-01

    Bacterial spore formers are prime organisms of concern in the food industry. Spores from the genus Bacillus are extremely stress resistant, most notably exemplified by high thermotolerance. This sometimes allows surviving spores to germinate and grow out to vegetative cells causing food spoilage and

  16. Study of hydraulic resistance and heat transfer in perforated-plate heat exchangers

    International Nuclear Information System (INIS)

    Shevyakova, S.A.; Orlov, V.K.

    1983-01-01

    Experimental data on hydraulic resistance and heat transfer in perforated-plate heat-exchangers with different internal geometry: diameter of perforation holes and distance between plates, have been studied and generalized. The plate perforation is formed by round holes 0.625; 0.9 and 1.65 mm in diameter. The distance between perforated plates ranged between 0.4 and 1.6 mm. Criterion ratios are suggested which inexplicitly take into account the effect of the above mentioned geometric parameters; these ratios are applicable for calculation of heat exchangers produced of perforated plates 0.5 mm thick with porosity of perforated plates in the limits of 0.3-0.6, the distance between plates being 0.4-1.6 mm and an arbitrary arrangement of holes in the neighbour plates relative to each other

  17. Multilevel Flow Modeling of Domestic Heating Systems

    DEFF Research Database (Denmark)

    Hu, Junjie; Lind, Morten; You, Shi

    2012-01-01

    of complementing this reasoning methodology. Domestic heating systems, as the main resource to meet the thermal requirements of end-users, have different implementations in Europe in order to achieve various degrees of controllability and heating efficiencies. As all the heating systems serve the same basic needs...... i.e. supplying and transferring thermal energy, it is off interest to use MFM to investigate similarities and differences between different implementations. In this paper, three typical domestic European heating systems, which differ from each other in the number of temperature sensors and auxiliary...... components e.g. storage tanks, are modeled using the MFM methodology. Both the goals and functions of material and energy processes and the control functions of the heating systems are represented in the MFM models. It is found that varying the physical system setup results in only little differences among...

  18. Viability and heat resistance of murine norovirus on bread.

    Science.gov (United States)

    Takahashi, Michiko; Takahashi, Hajime; Kuda, Takashi; Kimura, Bon

    2016-01-04

    Contaminated bread was the cause of a large-scale outbreak of norovirus disease in Japan in 2014. Contamination of seafood and uncooked food products by norovirus has been reported several times in the past; however the outbreak resulting from the contamination of bread products was unusual. A few reports on the presence of norovirus on bread products are available; however there have been no studies on the viability and heat resistance of norovirus on breads, which were investigated in this study. ce:italic>/ce:italic> strain 1 (MNV-1), a surrogate for human norovirus, was inoculated directly on 3 types of bread, but the infectivity of MNV-1 on bread samples was almost unchanged after 5days at 20°C. MNV-1 was inoculated on white bread that was subsequently heated in a toaster for a maximum of 2min. The results showed that MNV-1 remained viable if the heating period was insufficient to inactivate. In addition, bread dough contaminated with MNV-1 was baked in the oven. Our results indicated that MNV-1 may remain viable on breads if the heating duration or temperature is insufficient. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Combined electric heating system for timber frame houses

    Directory of Open Access Journals (Sweden)

    Igor Yu. Shelekhov

    2017-06-01

    Full Text Available Introduction: The article presents an overview of the factors affecting the decrease in energy costs during the construction and operation of frame type buildings. The authors propose the methods to increase energy efficiency in heating of frame type buildings. Materials and Methods: The experiment was conducted in an individual residential building with a total area of 80 square meters. Two panels with an infrared heating element and thermoelectric temperature sensors were used. Signals from the sensors were registered by measuring instruments. The amount of the consumed energy was measured by the electric meter. Results: The article identifies the problem and researches of parameters of the combined electric heating system, mutual influence of the two heating devices which are made on the basis of the heating elements with a positive temperature coefficient of resistance. The authors considered the basic scenario, and change of microclimate parameters. They studied the changes of microclimate parameters in the penetration of cold airflows into the room through the opening, and when the temperature of the walls decreases. Discussion and Conclusions: The heating unit using the effect of self-regulation reduces the time for establishing the stationary regime. It helps to reduce the inertia of the heating system and to promote rapid recovery of the microclimate parameters, reducing energy costs and heat loss.

  20. Heat-resistant mechanism of transgenic rape by 45Ca isotope tracer

    International Nuclear Information System (INIS)

    Xu Falun; Yang Yuanyou; Liu Ning; Liao Jiali; Yang Jijun; Tang Jun; Liu Zhibin; Yang Yi

    2012-01-01

    The Ca 2+ uptake differences of the rape with heat-resistant gene and the general rape were investigated by 45 Ca isotope tracer. The results showed that the rape with heat-resistant gene can strengthen the regulation of calcium absorption. The calcium regulation ability of the heat-resistant genes may be able to play in the rape aspect of the mechanism of resistance. (authors)

  1. Studying microstructure of heat resistant steel deoxidized by barium ferrosilicon

    Directory of Open Access Journals (Sweden)

    A. Z. Issagulov

    2016-07-01

    Full Text Available The paper examined the nature and distribution of non-metallic inclusions in the heat-resistant steel 12H1MF (0,12 % С, 1 % Сr, 0,5 - 0,6 Mo, 0,5 % V, ferrosilicobarim. As a reference, used by steel, deoxidized silicon. Melting was carried out in a laboratory, research-metallic inclusions, their shape and distribution, pollution index were studied according to conventional methods. Studies have shown that ferrosilicobarim deoxidation in an amount of 0,1 - 0,2 %, reduce the overall pollution index of non-metallic inclusions and change the nature of their distribution.

  2. Performance analysis of hybrid district heating system

    DEFF Research Database (Denmark)

    Mikulandric, Robert; Krajačić, Goran; Khavin, Gennadii

    2013-01-01

    more extensively used in district heating systems either separately or as a supplement to traditional fossil fuels in order to achieve national energy policy objectives. However, they are still facing problems such as high intermittences, high energy production costs and low load factors as well...... could reach up to 20% with utilisation of solar energy as supplement energy source in traditional fossil fuel based district heating systems. In this work, the performance of hybrid district energy system for a particular location will be analysed. For performance analysis, mathematical model......District heating system could contribute to more efficient heat generation through cogeneration power plants or waste heat utilization facilities and to increase of renewable energy sources share in total energy consumption. In the most developed EU countries, renewable energy sources have been...

  3. Solar/electric heating systems for the future energy system

    Energy Technology Data Exchange (ETDEWEB)

    Furbo, S.; Dannemand, M.; Perers, B. [and others

    2013-05-15

    The aim of the project is to elucidate how individual heating units for single family houses are best designed in order to fit into the future energy system. The units are based on solar energy, electrical heating elements/heat pump, advanced heat storage tanks and advanced control systems. Heat is produced by solar collectors in sunny periods and by electrical heating elements/heat pump. The electrical heating elements/heat pump will be in operation in periods where the heat demand cannot be covered by solar energy. The aim is to use the auxiliary heating units when the electricity price is low, e.g. due to large electricity production by wind turbines. The unit is equipped with an advanced control system where the control of the auxiliary heating is based on forecasts of the electricity price, the heat demand and the solar energy production. Consequently, the control is based on weather forecasts. Three differently designed heating units are tested in a laboratory test facility. The systems are compared on the basis of: 1) energy consumption for the auxiliary heating; 2) energy cost for the auxiliary heating; 3) net utilized solar energy. Starting from a normal house a solar combi system (for hot water and house heating) can save 20-30% energy cost, alone, depending on sizing of collector area and storage volume. By replacing the heat storage with a smart tank based on electric heating elements and a smart control based on weather/load forecast and electricity price information 24 hours ahead, another 30-40% can be saved. That is: A solar heating system with a solar collector area of about 10 m{sup 2}, a smart tank based on electric heating element and a smart control system, can reduce the energy costs of the house by at least 50%. No increase of heat storage volume is needed to utilize the smart control. The savings in % are similar for different levels of building insulation. As expected a heat pump in the system can further reduce the auxiliary electricity

  4. Competitive solar heating systems for residential buildings

    DEFF Research Database (Denmark)

    Furbo, Simon; Thür, Alexander; Fiedler, Frank

    2005-01-01

    The paper describes the ongoing research project “Competitive solar heating systems for residential buildings”. The aim of the project is to develop competitive solar combisystems which are attractive to buyers. The solar combisystems must be attractive compared to traditional energy systems, both....... In Denmark and Norway the focus is on solar heating/natural gas systems, and in Sweden and Latvia the focus is on solar heating/pellet systems. Additionally, Lund Institute of Technology and University of Oslo are studying solar collectors of various types being integrated into the roof and facade...... of the building....

  5. Safety characteristics of decay heat removal systems

    International Nuclear Information System (INIS)

    Hofmann, F.

    1991-01-01

    Safety features of the decay heat removal systems including power sunply and final heat sink are described. A rather high reliability and an utmost degree of independence from energy supply are goals to be attained in the design of the European Fast Reactor (EFR) decay heat removal scheme. Natural circulation is an ambitious design goal for EFR. All the considerations are performed within the frame of risk minimization

  6. Biofilm Formation Potential of Heat-Resistant Escherichia coli Dairy Isolates and the Complete Genome of Multidrug-Resistant, Heat-Resistant Strain FAM21845.

    Science.gov (United States)

    Marti, Roger; Schmid, Michael; Kulli, Sandra; Schneeberger, Kerstin; Naskova, Javorka; Knøchel, Susanne; Ahrens, Christian H; Hummerjohann, Jörg

    2017-08-01

    We tested the biofilm formation potential of 30 heat-resistant and 6 heat-sensitive Escherichia coli dairy isolates. Production of curli and cellulose, static biofilm formation on polystyrene (PS) and stainless steel surfaces, biofilm formation under dynamic conditions (Bioflux), and initial adhesion rates (IAR) were evaluated. Biofilm formation varied greatly between strains, media, and assays. Our results highlight the importance of the experimental setup in determining biofilm formation under conditions of interest, as correlation between different assays was often not a given. The heat-resistant, multidrug-resistant (MDR) strain FAM21845 showed the strongest biofilm formation on PS and the highest IAR and was the only strain that formed significant biofilms on stainless steel under conditions relevant to the dairy industry, and it was therefore fully sequenced. Its chromosome is 4.9 Mb long, and it harbors a total of five plasmids (147.2, 54.2, 5.8, 2.5, and 1.9 kb). The strain carries a broad range of genes relevant to antimicrobial resistance and biofilm formation, including some on its two large conjugative plasmids, as demonstrated in plate mating assays. IMPORTANCE In biofilms, cells are embedded in an extracellular matrix that protects them from stresses, such as UV radiation, osmotic shock, desiccation, antibiotics, and predation. Biofilm formation is a major bacterial persistence factor of great concern in the clinic and the food industry. Many tested strains formed strong biofilms, and especially strains such as the heat-resistant, MDR strain FAM21845 may pose a serious issue for food production. Strong biofilm formation combined with diverse resistances (some encoded on conjugative plasmids) may allow for increased persistence, coselection, and possible transfer of these resistance factors. Horizontal gene transfer may conceivably occur in the food production setting or the gastrointestinal tract after consumption. Copyright © 2017 Marti et al.

  7. Fundamental Study of a Combined Hyperthermia System with RF Capacitive Heating and Interstitial Heating

    OpenAIRE

    Saitoh, Yoshiaki; Hori, Junichi; 斉藤, 義明; 堀, 潤一

    2001-01-01

    Interstitial RF heating with an inserted electrode allows the heating position selection in a subject, but the narrow heating region is problematic. This study elucidates development of new interstitial RF heating methods, combining with external RF heating using paired electrodes, heating the subject broadly in advance in order to selectively extend the heating region. Two kinds of heating system were developed by controlling a differential mode and a common mode of RF currents. Heating expe...

  8. The role of heat resistance in thermorestoration of hydrated bacterial spores

    International Nuclear Information System (INIS)

    Friedman, Y.S.; Grecz, N.

    1973-01-01

    This study for the first time presents evidence of the distinct role played in thermorestoration by cellular determinants such as the resistance to heat and radiation, and the ionic state of spores. In the past only radiochemical determinants associated with radical annealment have been studied in hydrated systems. The basic heat resistance of spores plays a significant role in the precipitous drop in spore survival due to 0.45 Mrad radiation plus heat above 65-75 0 C for B.cereus and 75-95 0 C for B.stearothermophilus. The effect of the spores radiation resistance was not distinct except in the frozen state and at the saturation plateau of thermorestoration where the radiation resistant B.cereus showed ca. 1 log cycle higher survival than the radiation sensitive B.stearothermophilus. When spores are chemically converted into their H + and Ca ++ ionic forms, the H + spores are distinctly more responsive than Ca ++ spores to processes of radical annealment responsible for thermorestoration in hydrated spore systems. At temperatures of extensive thermorestoration of water radicals, H + spores showed higher survival than Ca ++ spores. (F.J.)

  9. District Heating Systems Performance Analyses. Heat Energy Tariff

    Science.gov (United States)

    Ziemele, Jelena; Vigants, Girts; Vitolins, Valdis; Blumberga, Dagnija; Veidenbergs, Ivars

    2014-12-01

    The paper addresses an important element of the European energy sector: the evaluation of district heating (DH) system operations from the standpoint of increasing energy efficiency and increasing the use of renewable energy resources. This has been done by developing a new methodology for the evaluation of the heat tariff. The paper presents an algorithm of this methodology, which includes not only a data base and calculation equation systems, but also an integrated multi-criteria analysis module using MADM/MCDM (Multi-Attribute Decision Making / Multi-Criteria Decision Making) based on TOPSIS (Technique for Order Performance by Similarity to Ideal Solution). The results of the multi-criteria analysis are used to set the tariff benchmarks. The evaluation methodology has been tested for Latvian heat tariffs, and the obtained results show that only half of heating companies reach a benchmark value equal to 0.5 for the efficiency closeness to the ideal solution indicator. This means that the proposed evaluation methodology would not only allow companies to determine how they perform with regard to the proposed benchmark, but also to identify their need to restructure so that they may reach the level of a low-carbon business.

  10. Investigation on Solar Heating System with Building-Integrated Heat Storage

    DEFF Research Database (Denmark)

    Heller, Alfred

    1996-01-01

    by PP-pipe heat exchanger. Heat demand is reduced due to direct solar heating and due to storage. The storage affects the heat demand passively due to higher temperatures. Hence heat loss is reduced and passive heating is optioned. In theory, by running the system flow backwards, active heating can......Traditional solar heating systems cover between 5 and 10% of the heat demand fordomestic hot water and comfort heating. By applying storage capacity this share can beincreased much. The Danish producer of solar heating systems, Aidt-Miljø, markets such a system including storage of dry sand heated...... be self-made to keep the price down. The system is working, but heat exchange from plastic piping to sand is rather poor. The dimensioning of the volume is rather difficult based on common knowledge. Passive heating, hence reduction of heat demand, due to the storage and especially due to the oversized...

  11. Clothing evaporative heat resistance - Proposal for improved representation in standards and models

    NARCIS (Netherlands)

    Havenith, G.; Holmér, I.; Hartog, E.A. den; Parsons, K.C.

    1999-01-01

    Clothing heat and vapour resistances are important inputs for standards and models dealing with thermal comfort, heat- and cold-stress. A vast database of static clothing heat resistance values is available, and this was recently expanded with correction equations to account for effects of movement

  12. Experimental investigations on solar heating/heat pump systems for single family houses

    DEFF Research Database (Denmark)

    Andersen, Elsa; Perers, Bengt

    In the period 2013-2017 the project “Experimental investigations on solar heat pump systems for single family houses” is carried out at Department of Civil Engineering, Technical University of Denmark. The aim of this project is to increase the knowledge of the heat and mass transfer...... in the combined solar heating/heat pump system type when the heat pump makes use of a horizontal ground source heat exchanger. The knowledge is gained by experimental investigations on a solar heating/heat pump system and forms the basis for improved marketed combined solar heating/heat pump systems....

  13. Radiant Heating and Cooling Systems. Part one

    DEFF Research Database (Denmark)

    Kim, Kwan Woo; Olesen, Bjarne W.

    2015-01-01

    The use of radiant heating systems has several thousand years of history.1,2 The early stage of radiant system application was for heating purposes, where hot air from flue gas (cooking, fires) was circulated under floors or in walls. After the introduction of plastic piping water-based radiant h...... installations. For similar reasons, as well as possible peak load reduction and energy savings, radiant systems are being widely applied in commercial and industrial buildings....

  14. Are modern heating systems ruining older chimneys

    Energy Technology Data Exchange (ETDEWEB)

    Roemer, W.

    1989-03-01

    When it is a question of saving energy, burners, heating boilers and chimneys must be optimally suited to one another. Only: Older chimneys were not built for thrifty energy consumption. For which reason modern, energy-saving low-temperature heating does not find the upward lift that it needs in older chimneys. And since natural gas produces about 50% more steam in the waste gas than oil-fired heating, chimney trouble is almost pre-programmed in the conversion. The author of this article maintains that the problems can be solved. Older chimneys can also cope with modern heating systems if precautionary measures are taken in time.

  15. MULTIFUNCTIONAL SOLAR SYSTEMS FOR HEATING AND COOLING

    Directory of Open Access Journals (Sweden)

    Doroshenko A.V.

    2010-12-01

    Full Text Available The basic circuits of multifunctional solar systems of air drainage, heating (hot water supply and heating, cooling and air conditioning are developed on the basis of open absorption cycle with a direct absorbent regeneration. Basic decisions for new generation of gas-liquid solar collectors are developed. Heat-mass-transfer apparatus included in evaporative cooling system, are based on film interaction of flows of gas and liquid and in them, for the creation of nozzle, multi-channel structures from polymeric materials and porous ceramics are used. Preliminary analysis of multifunctional systems possibilities is implemented.

  16. 49 CFR 179.201-5 - Postweld heat treatment and corrosion resistance.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Postweld heat treatment and corrosion resistance....201-5 Postweld heat treatment and corrosion resistance. (a) Tanks and attachments welded directly... tested to demonstrate that they possess the corrosion resistance specified in § 179.200-7(d), Footnote 2...

  17. OPTIMUM HEAT STORAGE DESIGN FOR SDHW SYSTEMS

    DEFF Research Database (Denmark)

    Shah, Louise Jivan; Furbo, Simon

    1997-01-01

    . The other model is especially designed for low flow SDHW systems based on a mantle tank.The tank design’s influence on the thermal performance of the SDHW systems has been investigated in a way where only one tank parameter has been changed at a time in the calculations. In this way a direct analysis...... of the tank design’s influence on the thermal performance of the systems is possible. By means of the calculations design rules for the two heat storage types are proposed.......Two simulation models have been used to analyse the heat storage design’s influence on the thermal performance of solar domestic hot water (SDHW) systems. One model is especially designed for traditional SDHW systems based on a heat storage design where the solar heat exchanger is a built-in spiral...

  18. Optimal Control of Solar Heating System

    KAUST Repository

    Huang, Bin-Juine

    2017-02-21

    Forced-circulation solar heating system has been widely used in process and domestic heating applications. Additional pumping power is required to circulate the water through the collectors to absorb the solar energy. The present study intends to develop a maximum-power point tracking control (MPPT) to obtain the minimum pumping power consumption at an optimal heat collection. The net heat energy gain Qnet (= Qs − Wp/ηe) was found to be the cost function for MPPT. The step-up-step-down controller was used in the feedback design of MPPT. The field test results show that the pumping power is 89 W at Qs = 13.7 kW and IT = 892 W/m2. A very high electrical COP of the solar heating system (Qs/Wp = 153.8) is obtained.

  19. Genome-wide deficiency screen for the genomic regions responsible for heat resistance in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Teramura Kouhei

    2011-06-01

    Full Text Available Abstract Background Temperature adaptation is one of the most important determinants of distribution and population size of organisms in nature. Recently, quantitative trait loci (QTL mapping and gene expression profiling approaches have been used for detecting candidate genes for heat resistance. However, the resolution of QTL mapping is not high enough to examine the individual effects of various genes in each QTL. Heat stress-responsive genes, characterized by gene expression profiling studies, are not necessarily responsible for heat resistance. Some of these genes may be regulated in association with the heat stress response of other genes. Results To evaluate which heat-responsive genes are potential candidates for heat resistance with higher resolution than previous QTL mapping studies, we performed genome-wide deficiency screen for QTL for heat resistance. We screened 439 isogenic deficiency strains from the DrosDel project, covering 65.6% of the Drosophila melanogaster genome in order to map QTL for thermal resistance. As a result, we found 19 QTL for heat resistance, including 3 novel QTL outside the QTL found in previous studies. Conclusion The QTL found in this study encompassed 19 heat-responsive genes found in the previous gene expression profiling studies, suggesting that they were strong candidates for heat resistance. This result provides new insights into the genetic architecture of heat resistance. It also emphasizes the advantages of genome-wide deficiency screen using isogenic deficiency libraries.

  20. LPV Identification of a Heat Distribution System

    DEFF Research Database (Denmark)

    Trangbæk, K; Bendtsen, Jan Dimon

    2010-01-01

    This paper deals with incremental system identification of district heating systems to improve control performance. As long as various parameters, e.g. valve settings, are kept fixed, the dynamics of district heating systems can be approximated well by linear models; however, the dynamics change...... significantly when these parameters change. For this reason, we attempt to identify the system using linear parameter varying models. We demonstrate how the so-called ``Hansen Scheme," for linear time-invariant systems, can be employed for incremental identification of linear parameter varying systems as well....... The approach is tested on a laboratory setup emulating a district heating system, where local controllers regulate pumps connected to a common supply. Experiments show that cross-couplings in the system can indeed be identified in closed-loop operation....

  1. Performance of a Solar Heating System with Photovoltaic Thermal Hybrid Collectors and Heat Pump

    DEFF Research Database (Denmark)

    Dannemand, Mark; Furbo, Simon; Perers, Bengt

    2017-01-01

    The energy consumption in buildings accounts for a large part of the World’s CO2 emissions. Much energy is used for appliances, domestic hot water preparation and space heating. In solar heating systems, heat is captured by solar collectors when the sun is shining and used for heating purposes....... When the solar collectors are unable to supply the heat demand an auxiliary heat source is used. Heat pumps can generate this heat. Liquid/water heat pumps have better performance than air/water heat pumps in cold climates but requires installation of a tubing system for the cold side of the heat pump....... The tubes are typically placed in the ground, requires a significant land area and increase the installation cost. A new system design of a solar heating system with two storage tanks and a liquid/water heat pump is presented. The system consists of PVT collectors that generate both heat and electricity...

  2. Oxidation Resistance of Medium-Carbon Heat-Resistant Cr-Al Steels in Extreme Conditions

    Directory of Open Access Journals (Sweden)

    Mykhail M. Yamshinskij

    2017-10-01

    Full Text Available Background. From the analysis of exploitation of heat-resistant details of thermal power and metallurgical equipment, it was found that the basic characteristic of metallic materials working under extreme conditions is oxidation resistance. However, the choice of materials for work in the conditions of high temperatures and aggressive environments should be made taking into account not only its oxidation resistance but also the possibility of this material to work long time in the conditions of thermal cycling without being damaged, thus thinking about its heat-resistance. Consequently, it is tremendously important to determine the oxidation resistance of iron-based alloys in extreme conditions depending on the presence of main elements – chrome and aluminium – in their content on the basis of study of formation processes on the item surface of high-quality protective oxides films. Objective. The aim of the paper is to establish the selection rules of heat-resistant iron-based alloys for work in extreme conditions depending on temperatures and aggressive environments and to accumulate some information on their oxidation resistance for the creation of a database and development of methodology how to forecast special properties of alloys. Methods. Models with 10 mm in diameter and 20 mm in length were tested in a tubular stove at the temperature of 1200 and 1250 °C during 100 hours. Oxidation resistance was determined by a weight method. Phase composition and structure were explored by modern X-ray structural and metallographic methods. Results. Processes and mechanisms of formation of oxide scale in the conditions of exploitation of items under the temperature 1250 °C in different aggressive environments are established. The optimum boundaries of concentration of basic chemical elements – chrome and aluminium – in heat-resistant alloys for work in extreme conditions depending on temperatures and environments are determined. A database

  3. District heating with SLOWPOKE energy systems

    International Nuclear Information System (INIS)

    Lynch, G.F.

    1988-03-01

    The SLOWPOKE Energy System, a benign nuclear heat source designed to supply 10 thermal megawatts in the form of hot water for local heating systems in buildings and institutions, is at the forefront of these developments. A demonstration unit has been constructed in Canada and is currently undergoing an extensive test program. Because the nuclear heat source is small, operates at atmospheric pressure, and produces hot water below 100 degrees Celcius, intrinsic safety features will permit minimum operator attention and allow the heat source to be located close to the load and hence to people. In this way, a SLOWPOKE Energy System can be considered much like the oil- or coal-fired furnace it is designed to replace. The low capital investment requirements, coupled with a high degree of localization, even for the first unit, are seen as attractive features for the implementation of SLOWPOKE Energy Systems in many countries

  4. Investigation of the thermal resistance of timber attic spaces with reflective foil and bulk insulation, heat flow up

    Energy Technology Data Exchange (ETDEWEB)

    Belusko, M.; Bruno, F.; Saman, W. [Institute for Sustainable Systems and Technologies, University of South Australia, Mawson Lakes Boulevard, SA 5095 (Australia)

    2011-01-15

    An experimental investigation was undertaken in which the thermal resistance for the heat flow through a typical timber framed pitched roofing system was measured under outdoor conditions for heat flow up. The measured thermal resistance of low resistance systems such as an uninsulated attic space and a reflective attic space compared well with published data. However, with higher thermal resistance systems containing bulk insulation within the timber frame, the measured result for a typical installation was as low as 50% of the thermal resistance determined considering two dimensional thermal bridging using the parallel path method. This result was attributed to three dimensional heat flow and insulation installation defects, resulting from the design and construction method used. Translating these results to a typical house with a 200 m{sup 2} floor area, the overall thermal resistance of the roof was at least 23% lower than the overall calculated thermal resistance including two dimensional thermal bridging. When a continuous layer of bulk insulation was applied to the roofing system, the measured values were in agreement with calculated resistances representing a more reliable solution. (author)

  5. SIMS prototype system 1: Design data brochure. [solar heating system

    Science.gov (United States)

    1978-01-01

    A prototype solar heating and hot water system using air as the collector fluid and a pebble bed for heat storage was designed for installation into a single family dwelling. The system, subsystem, and installation requirements are described. System operation and performance are discussed, and procedures for sizing the system to a specific site are presented.

  6. Design of biomass district heating systems

    International Nuclear Information System (INIS)

    Vallios, Ioannis; Tsoutsos, Theocharis; Papadakis, George

    2009-01-01

    The biomass exploitation takes advantage of the agricultural, forest, and manure residues and in extent, urban and industrial wastes, which under controlled burning conditions, can generate heat and electricity, with limited environmental impacts. Biomass can - significantly - contribute in the energy supplying system, if the engineers will adopt the necessary design changes to the traditional systems and become more familiar with the design details of the biomass heating systems. The aim of this paper is to present a methodology of the design of biomass district heating systems taking into consideration the optimum design of building structure and urban settlement around the plant. The essential energy parameters are presented for the size calculations of a biomass burning-district heating system, as well as for the environmental (i.e. Greenhouse Gas Emissions) and economic evaluation (i.e. selectivity and viability of the relevant investment). Emphasis has been placed upon the technical parameters of the biomass system, the economic details of the boiler, the heating distribution network, the heat exchanger and the Greenhouse Gas Emissions

  7. Design of biomass district heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Vallios, Ioannis [Energy Applications Mgr., METRON Ltd Engineering Company (Greece); Tsoutsos, Theocharis [Department of Environmental Engineering, Technical University of Crete, GR-73100 Chania (Greece); Papadakis, George [Department of Natural Resources and Agricultural Engineering, Agricultural University of Athens (Greece)

    2009-04-15

    The biomass exploitation takes advantage of the agricultural, forest, and manure residues and in extent, urban and industrial wastes, which under controlled burning conditions, can generate heat and electricity, with limited environmental impacts. Biomass can - significantly - contribute in the energy supplying system, if the engineers will adopt the necessary design changes to the traditional systems and become more familiar with the design details of the biomass heating systems. The aim of this paper is to present a methodology of the design of biomass district heating systems taking into consideration the optimum design of building structure and urban settlement around the plant. The essential energy parameters are presented for the size calculations of a biomass burning-district heating system, as well as for the environmental (i.e. Greenhouse Gas Emissions) and economic evaluation (i.e. selectivity and viability of the relevant investment). Emphasis has been placed upon the technical parameters of the biomass system, the economic details of the boiler, the heating distribution network, the heat exchanger and the Greenhouse Gas Emissions. (author)

  8. Demonstration of Three Corrosion-Resistant Sustainable Roofing Systems

    Science.gov (United States)

    2013-06-01

    the location to demonstrate (1) a heat-resistant metal shingle roofing sys- tem with above-sheathing ventilation (ASV), (2) a sloped-roof conversion...3 2.2.1 Stone-coated metal shingle system with ASV...10 2.3.1 Stone-coated metal shingle system with ASV ......................................................... 10

  9. Optimization of Solar Water Heating System under Time and Spatial Partition Heating in Rural Dwellings

    OpenAIRE

    Yanfeng Liu; Tao Li; Yaowen Chen; Dengjia Wang

    2017-01-01

    This paper proposes the application of time and spatial partition heating to a solar water heating system. The heating effect and system performance were analyzed under the continuous and whole space heating and time and spatial partition heating using TRNSYS. The results were validated by comparing with the test results of the demonstration building. Compared to continuous and whole space heating, the use of time and spatial partition heating increases the solar fraction by 16.5%, reduces th...

  10. Symmetric miniaturized heating system for active microelectronic devices.

    Science.gov (United States)

    McCracken, Michael; Mayer, Michael; Jourard, Isaac; Moon, Jeong-Tak; Persic, John

    2010-07-01

    To qualify interconnect technologies such as microelectronic fine wire bonds for mass production of integrated circuit (IC) packages, it is necessary to perform accelerated aging tests, e.g., to age a device at an elevated temperature or to subject the device to thermal cycling and measure the decrease of interconnect quality. There are downsides to using conventional ovens for this as they are relatively large and have relatively slow temperature change rates, and if electrical connections are required between monitoring equipment and the device being heated, they must be located inside the oven and may be aged by the high temperatures. Addressing these downsides, a miniaturized heating system (minioven) is presented, which can heat individual IC packages containing the interconnects to be tested. The core of this system is a piece of copper cut from a square shaped tube with high resistance heating wire looped around it. Ceramic dual in-line packages are clamped against either open end of the core. One package contains a Pt100 temperature sensor and the other package contains the device to be aged placed in symmetry to the temperature sensor. According to the temperature detected by the Pt100, a proportional-integral-derivative controller adjusts the power supplied to the heating wire. The system maintains a dynamic temperature balance with the core hot and the two symmetric sides with electrical connections to the device under test at a cooler temperature. Only the face of the package containing the device is heated, while the socket holding it remains below 75 degrees C when the oven operates at 200 degrees C. The minioven can heat packages from room temperature up to 200 degrees C in less than 5 min and maintain this temperature at 28 W power. During long term aging, a temperature of 200 degrees C was maintained for 1120 h with negligible resistance change of the heating wires after 900 h (heating wire resistance increased 0.2% over the final 220 h). The

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

    DEFF Research Database (Denmark)

    Zvingilaite, Erika; Balyk, Olexandr

    2014-01-01

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

  12. Dual energy use systems: District heating survey

    Science.gov (United States)

    1980-07-01

    The current status of and problems facing district heating systems operated by electric utilities were identified. The technical and economic factors which can affect the present and future success of district heating systems in the United States were evaluated. A survey of 59 district heating electric utilities was conducted to determine the current status of the industry. Questions developed to obtain data on technical, economic, regulator, and marketing factors were included in the survey. Literature on district heating in the U.S. and abroad was collected from governments, industry and foreign sources and reviewed to aid in evaluating the current and future potential of the industry. Interviews were held with executives of 16 utilities that operate district heating systems in order to determine corporate attitudes. A summary of the literature obtained is provided. Survey results are tabulated and described. The interviews and survey data were used to compile 10 case studies of utilities operating district heating systems under a braod range of circumstances.

  13. CAREM-25: Residual heat removal system

    International Nuclear Information System (INIS)

    Arvia, Roberto P.; Coppari, Norberto R.; Gomez de Soler, Susana M.; Ramilo, Lucia B.

    2000-01-01

    The objective of this work was the definition and consolidation of the residual heat removal system for the CAREM 25 reactor. The function of this system is cool down the primary circuit, removing the core decay heat from hot stand-by to cold shutdown and during refueling. In addition, this system heats the primary water from the cold shutdown condition to hot stand-by condition during the reactor start up previous to criticality. The system has been designed according to the requirements of the standards: ANSI/ANS 51.1 'Nuclear safety criteria for the design of stationary PWR plants'; ANSI/ANS 58.11 'Design criteria for safe shutdown following selected design basis events in light water reactors' and ANSI/ANS 58.9 'Single failure criteria for light water reactor safety-related fluid systems'. The suggested design fulfills the required functions and design criteria standards. (author)

  14. Heat resistance of Salmonella in various egg products.

    Science.gov (United States)

    Garibaldi, J A; Straka, R P; Ijichi, K

    1969-04-01

    The heat-resistance characteristics of Salmonella typhimurium Tm-1, a reference strain in the stationary phase of growth, were determined at several temperatures in the major types of products produced by the egg industry. The time required to kill 90% of the population (D value) at a given temperature in specific egg products was as follows: at 60 C (140 F), D = 0.27 min for whole egg; D = 0.60 min for whole egg plus 10% sucrose; D = 1.0 min for fortified whole egg; D = 0.20 min for egg white (pH 7.3), stabilized with aluminum; D = 0.40 min for egg yolk; D = 4.0 min for egg yolk plus 10% sucrose; D = 5.1 min for egg yolk plus 10% NaCl; D = 1.0 min for scrambled egg mix; at 55 C (131 F), D = 0.55 min for egg white (pH 9.2); D = 1.2 min for egg white (pH 9.2) plus 10% sucrose. The average Z value (number of degrees, either centigrade or fahrenheit, for a thermal destruction time curve to traverse one logarithmic cycle) was 4.6 C (8.3 F) with a range from 4.2 to 5.3 C. Supplementation with 10% sucrose appeared to have a severalfold greater effect on the heat stabilization of egg white proteins than on S. typhimurium Tm-1. This information should be of value in the formulation of heat treatments to insure that all egg products be free of viable salmonellae.

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  16. Understanding The Resistance to Health Information Systems

    OpenAIRE

    David Ackah; Angelito E Alvarado; Heru Santoso Wahito Nugroho; Sanglar Polnok; Wiwin Martiningsih

    2017-01-01

    User resistance is users’ opposition to system implementation. Resistance often occurs as a result of a mismatch between management goals and employee preferences. There are two types of resistance to health iformation system namely active resistance and passive resistance. The manifestation of active resistance are being critical,  blaming/accusing, blocking, fault finding, sabotaging, undermining, ridiculing, intimidating/threatening, starting rumors, appealing to fear, manipulating arguing...

  17. Solar Powered Heat Control System for Cars

    OpenAIRE

    Abin John; Jithin Thomas

    2014-01-01

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

  18. Carbon nanotube heat-exchange systems

    Science.gov (United States)

    Hendricks, Terry Joseph; Heben, Michael J.

    2008-11-11

    A carbon nanotube heat-exchange system (10) and method for producing the same. One embodiment of the carbon nanotube heat-exchange system (10) comprises a microchannel structure (24) having an inlet end (30) and an outlet end (32), the inlet end (30) providing a cooling fluid into the microchannel structure (24) and the outlet end (32) discharging the cooling fluid from the microchannel structure (24). At least one flow path (28) is defined in the microchannel structure (24), fluidically connecting the inlet end (30) to the outlet end (32) of the microchannel structure (24). A carbon nanotube structure (26) is provided in thermal contact with the microchannel structure (24), the carbon nanotube structure (26) receiving heat from the cooling fluid in the microchannel structure (24) and dissipating the heat into an external medium (19).

  19. 46 CFR 153.430 - Heat transfer systems; general.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Heat transfer systems; general. 153.430 Section 153.430... Temperature Control Systems § 153.430 Heat transfer systems; general. Each cargo cooling system required by... separated from all other cooling and heating systems; and (c) Allow manual regulation of the system's heat...

  20. Magnus: A New Resistive MHD Code with Heat Flow Terms

    Science.gov (United States)

    Navarro, Anamaría; Lora-Clavijo, F. D.; González, Guillermo A.

    2017-07-01

    We present a new magnetohydrodynamic (MHD) code for the simulation of wave propagation in the solar atmosphere, under the effects of electrical resistivity—but not dominant—and heat transference in a uniform 3D grid. The code is based on the finite-volume method combined with the HLLE and HLLC approximate Riemann solvers, which use different slope limiters like MINMOD, MC, and WENO5. In order to control the growth of the divergence of the magnetic field, due to numerical errors, we apply the Flux Constrained Transport method, which is described in detail to understand how the resistive terms are included in the algorithm. In our results, it is verified that this method preserves the divergence of the magnetic fields within the machine round-off error (˜ 1× {10}-12). For the validation of the accuracy and efficiency of the schemes implemented in the code, we present some numerical tests in 1D and 2D for the ideal MHD. Later, we show one test for the resistivity in a magnetic reconnection process and one for the thermal conduction, where the temperature is advected by the magnetic field lines. Moreover, we display two numerical problems associated with the MHD wave propagation. The first one corresponds to a 3D evolution of a vertical velocity pulse at the photosphere-transition-corona region, while the second one consists of a 2D simulation of a transverse velocity pulse in a coronal loop.

  1. Dynamic thermal characteristics of heat pipe via segmented thermal resistance model for electric vehicle battery cooling

    Science.gov (United States)

    Liu, Feifei; Lan, Fengchong; Chen, Jiqing

    2016-07-01

    Heat pipe cooling for battery thermal management systems (BTMSs) in electric vehicles (EVs) is growing due to its advantages of high cooling efficiency, compact structure and flexible geometry. Considering the transient conduction, phase change and uncertain thermal conditions in a heat pipe, it is challenging to obtain the dynamic thermal characteristics accurately in such complex heat and mass transfer process. In this paper, a ;segmented; thermal resistance model of a heat pipe is proposed based on thermal circuit method. The equivalent conductivities of different segments, viz. the evaporator and condenser of pipe, are used to determine their own thermal parameters and conditions integrated into the thermal model of battery for a complete three-dimensional (3D) computational fluid dynamics (CFD) simulation. The proposed ;segmented; model shows more precise than the ;non-segmented; model by the comparison of simulated and experimental temperature distribution and variation of an ultra-thin micro heat pipe (UMHP) battery pack, and has less calculation error to obtain dynamic thermal behavior for exact thermal design, management and control of heat pipe BTMSs. Using the ;segmented; model, the cooling effect of the UMHP pack with different natural/forced convection and arrangements is predicted, and the results correspond well to the tests.

  2. The Heat Resistance of Microbial Cells Represented by D Values Can be Estimated by the Transition Temperature and the Coefficient of Linear Expansion.

    Science.gov (United States)

    Nakanishi, Koichi; Kogure, Akinori; Deuchi, Keiji; Kuwana, Ritsuko; Takamatsu, Hiromu; Ito, Kiyoshi

    2015-01-01

    We previously developed a method for evaluating the heat resistance of microorganisms by measuring the transition temperature at which the coefficient of linear expansion of a cell changes. Here, we performed heat resistance measurements using a scanning probe microscope with a nano thermal analysis system. The microorganisms studied included six strains of the genus Bacillus or related genera, one strain each of the thermophilic obligate anaerobic bacterial genera Thermoanaerobacter and Moorella, two strains of heat-resistant mold, two strains of non-sporulating bacteria, and one strain of yeast. Both vegetative cells and spores were evaluated. The transition temperature at which the coefficient of linear expansion due to heating changed from a positive value to a negative value correlated strongly with the heat resistance of the microorganism as estimated from the D value. The microorganisms with greater heat resistance exhibited higher transition temperatures. There was also a strong negative correlation between the coefficient of linear expansion and heat resistance in bacteria and yeast, such that microorganisms with greater heat resistance showed lower coefficients of linear expansion. These findings suggest that our method could be useful for evaluating the heat resistance of microorganisms.

  3. 46 CFR 154.178 - Contiguous hull structure: Heating system.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Contiguous hull structure: Heating system. 154.178... Equipment Hull Structure § 154.178 Contiguous hull structure: Heating system. The heating system for... the heating capacity to meet § 154.174(b)(2) or § 154.176(b)(2); (b) Have stand-by heating to provide...

  4. On-line corrosion monitoring in district heating systems

    DEFF Research Database (Denmark)

    Richter, Sonja; Thorarinsdottir, R.I.; Hilbert, Lisbeth Rischel

    2004-01-01

    Traditionally corrosion monitoring in district heating systems has been performed offline via weight loss coupons. These measurements give information about the past and not the present situation and require long exposure time (weeks or months). The good quality of district heating medium makes...... corrosion monitoring a challenge. Under normal conditions the pH is high (app. 9), conductivity is low (app. 10-200 µS/cm) and the concentration of dissolved oxygen is negligible. The low corrosion rates (in the order of µm/y) are difficult to measure and furthermore, factors such as hydrogen sulphide......), Electrochemical Noise (EN) and Zero Resistance Ammetry (ZRA). Electrochemical Resistance (ER) has also been used to measure corrosion. The method traditionally only measures corrosion off-line but with newly developed high-sensitive ER technique developed by MetriCorr in Denmark, on-line monitoring is possible...

  5. Heat transfer analysis of underground U-type heat exchanger of ground source heat pump system.

    Science.gov (United States)

    Pei, Guihong; Zhang, Liyin

    2016-01-01

    Ground source heat pumps is a building energy conservation technique. The underground buried pipe heat exchanging system of a ground source heat pump (GSHP) is the basis for the normal operation of an entire heat pump system. Computational-fluid-dynamics (CFD) numerical simulation software, ANSYS-FLUENT17.0 have been performed the calculations under the working conditions of a continuous and intermittent operation over 7 days on a GSHP with a single-well, single-U and double-U heat exchanger and the impact of single-U and double-U buried heat pipes on the surrounding rock-soil temperature field and the impact of intermittent operation and continuous operation on the outlet water temperature. The influence on the rock-soil temperature is approximately 13 % higher for the double-U heat exchanger than that of the single-U heat exchanger. The extracted energy of the intermittent operation is 36.44 kw·h higher than that of the continuous mode, although the running time is lower than that of continuous mode, over the course of 7 days. The thermal interference loss and quantity of heat exchanged for unit well depths at steady-state condition of 2.5 De, 3 De, 4 De, 4.5 De, 5 De, 5.5 De and 6 De of sidetube spacing are detailed in this work. The simulation results of seven working conditions are compared. It is recommended that the side-tube spacing of double-U underground pipes shall be greater than or equal to five times of outer diameter (borehole diameter: 180 mm).

  6. Evaluation of Heat Capacity and Resistance to Cyclic Oxidation of Nickel Superalloys

    Directory of Open Access Journals (Sweden)

    Przeliorz R.

    2014-08-01

    Full Text Available Paper presents the results of evaluation of heat resistance and specific heat capacity of MAR-M-200, MAR-M-247 and Rene 80 nickel superalloys. Heat resistance was evaluated using cyclic method. Every cycle included heating in 1100°C for 23 hours and cooling for 1 hour in air. Microstructure of the scale was observed using electron microscope. Specific heat capacity was measured using DSC calorimeter. It was found that under conditions of cyclically changing temperature alloy MAR-M-247 exhibits highest heat resistance. Formed oxide scale is heterophasic mixture of alloying elements, under which an internal oxidation zone was present. MAR-M-200 alloy has higher specific heat capacity compared to MAR-M-247. For tested alloys in the temperature range from 550°C to 800°C precipitation processes (γ′, γ″ are probably occurring, resulting in a sudden increase in the observed heat capacity.

  7. 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

  8. After-heat removing system in FBR type reactor

    International Nuclear Information System (INIS)

    Ohashi, Yukio.

    1990-01-01

    The after-heat removing system of the present invention removes the after heat generated in a reactor core without using dynamic equipments such as pumps or blowers. There are disposed a first heat exchanger for heating a heat medium by the heat in a reactor container and a second heat exchanger situated above the first heat exchanger for spontaneously air-cooling the heat medium. Recycling pipeways connect the first and the second heat exchangers to form a recycling path for the heat medium. Then, since the second heat exchanger for spontaneously air-cooling the heat medium is disposed above the first heat exchanger and they are connected by the recycling pipeways, the heat medium can be circulated spontaneously. Accordingly, dynamic equipments such as pumps or blowers are no more necessary. As a result, the after-heat removing system of the FBR type reactor of excellent safety and reliability can be obtained. (I.S.)

  9. Effects of Floor Covering Resistance of a Radiant Floor on System Energy and Exergy Performances

    DEFF Research Database (Denmark)

    Kazanci, Ongun Berk; Shukuya, Masanori; Olesen, Bjarne W.

    2016-01-01

    Floor covering resistance (material and thickness) can be influenced by subjective choices (architectural design, interior design, texture, etc.) with significant effects on the performance of a radiant heating and cooling system. To study the effects of floor covering resistance on system...... performance, a water-based radiant floor heating and cooling system (dry, wooden construction) was considered to be coupled to an air-to-water heat pump, and the effects of varying floor covering resistances (0.05 m2K/W, 0.09 m2K/W and 0.15 m2K/W) on system performance were analyzed in terms of energy...... and exergy. In order to achieve the same heating and cooling outputs, higher average water temperatures are required in the heating mode (and lower temperatures in the cooling mode) with increasing floor covering resistance. These temperature requirements decrease the heat pump’s performance (lower...

  10. Upgrade of ICRF heating system on EAST

    International Nuclear Information System (INIS)

    Chen Gen; Zhao Yanpin; Mao Yuzhou

    2013-01-01

    ICRF (Ion Cyclotron Range of Frequency) heating is an essential heating and current drive tool on EAST (Experimental Advanced Superconducting Tokamak). The high-power steady-state transmitters were designed as a part of research and development of ICRF heating system which aimed at output power of 1.5 MW for 1000 s in a frequency range of 25 to 70 MHz. There are 3 stage power amplifiers for each transmitter. Tube TH525A and TH535 were chosen for drive power amplifier (DPA) and final power amplifier (FPA), respectively. The power supply system of DPA and FPA were upgraded by using reliable PSM high voltage sources, whose response time is less than 5 μs. The ICRF system, which consists of 8 transmitters, will give out more than 10 MW total output power in the future. Four of them have been already fabricated, and another four are under construction. Three liquid stub tuners are used for impedance matching between antennas and transmitters, which can be only tuned shot to shot. There are two fast wave heating antennas which are assembled at I port and B port on EAST. Several projects are in progress including fast response impedance matching, distributed data acquisition and control system and so on for EAST ICRF heating system. (author)

  11. Energy Savings for Solar Heating Systems

    DEFF Research Database (Denmark)

    Thür, Alexander; Furbo, Simon; Shah, Louise Jivan

    2004-01-01

    , various simulations of solar heating systems were done for different hot water demands and collector sizes. The result shows that the potential of fuel reduction can be much higher than the solar gain of the solar thermal system. For some conditions the fuel reduction can be up to the double of the solar...

  12. Ion cyclotron resonance heating system on Aditya

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Abstract. An ion cyclotron resonance heating (ICRH) system has been designed, fabricated indigenously and commissioned on Tokamak Aditya. The system has been commissioned to operate between 20·0 and 47·0 MHz at a maximum power of 200 kW continuous wave (CW). Duration of 500 ms is sufficient for operation.

  13. Solar-heating system design package

    Science.gov (United States)

    1980-01-01

    Report describes solar heating system composed of warm-air solar collector, logic control unit, and switching and transport unit, that meets government standards for installation in residential dwellings. Text describes system operation and performance specifications complemented by comprehensive set of subcomponent design drawings.

  14. A simplified heat pump model for use in solar plus heat pump system simulation studies

    DEFF Research Database (Denmark)

    Perers, Bengt; Andersen, Elsa; Nordman, Roger

    2012-01-01

    Solar plus heat pump systems are often very complex in design, with sometimes special heat pump arrangements and control. Therefore detailed heat pump models can give very slow system simulations and still not so accurate results compared to real heat pump performance in a system. The idea here...

  15. Control system of power supply for resistance welding machine

    Directory of Open Access Journals (Sweden)

    Світлана Костянтинівна Поднебенна

    2017-06-01

    Full Text Available This article describes the existing methods of heat energy stabilizing, which are realized in thyristor power supplies for resistance welding machines. The advantages and features of thyristor power supplies have been described. A control system of power supply for resistance welding machine with stabilization of heat energy in a welding spot has been developed. Measurements are performed in primary winding of a welding transformer. Weld spot heating energy is calculated as the difference between the energy, consumed from the mains, and the energy losses in the primary and secondary circuits of the welding transformer as well as the energy losses in the transformer core. Algorithms of digital signal processing of the developed control system are described in the article. All measurements and calculations are preformed automatically in real-time. Input signals to the control system are: transformer primary voltage and current, temperature of the welding circuit. The designed control system ensures control of the welding heat energy and is not influenced by the supply voltage and impedance changes caused by insertion of the ferromagnetic mass in the welding circuit, the temperature change during the welding process. The developed control system for resistance welding machine makes it possible to improve the quality of welded joints, increase the efficiency of the resistance welding machine

  16. Impact resistant battery enclosure systems

    Energy Technology Data Exchange (ETDEWEB)

    Tsutsui, Waterloo; Feng, Yuezhong; Chen, Weinong Wayne; Siegmund, Thomas Heinrich

    2017-10-31

    Battery enclosure arrangements for a vehicular battery system. The arrangements, capable of impact resistance include plurality of battery cells and a plurality of kinetic energy absorbing elements. The arrangements further include a frame configured to encase the plurality of the kinetic energy absorbing elements and the battery cells. In some arrangements the frame and/or the kinetic energy absorbing elements can be made of topologically interlocked materials.

  17. Design of A District Heating System Including The Upgrading of Residual Industrial Waste Heat

    NARCIS (Netherlands)

    Falcao, P.W.; Mesbah, A.; Suherman, M.V.; Wennekes, S.

    2005-01-01

    This study was aimed to evaluate the feasibility of using a waste heat stream from DSM for a District Heating System. A conceptual design was carried out with emphasis on the unit for upgrading the residual waste heat. Having reviewed heat pump technology, mechanical heat pump was found to be the

  18. One-Loop Operation of Primary Heat Transport System in MONJU During Heat Transport System Modifications

    International Nuclear Information System (INIS)

    Goto, T.; Tsushima, H.; Sakurai, N.; Jo, T.

    2006-01-01

    MONJU is a prototype fast breeder reactor (FBR). Modification work commenced in March 2005. Since June 2004, MONJU has changed to one-loop operation of the primary heat transport system (PHTS) with all of the secondary heat transport systems (SHTS) drained of sodium. The purposes of this change are to shorten the modification period and to reduce the cost incurred for circuit trace heating electrical consumption. Before changing condition, the following issues were investigated to show that this mode of operation was possible. The heat loss from the reactor vessel and the single primary loop must exceed the decay heat by an acceptable margin but the capacity of pre-heaters to keep the sodium within the primary vessel at about 200 deg. C must be maintained. With regard to the heat loss and the decay heat, the estimated heat loss in the primary system was in the range of 90-170 kW in one-loop operation, and the calculated decay heat was 21.2 kW. Although the heat input of the primary pump was considered, it was clear that circuit heat loss greatly exceeded the decay heat. As for pre-heaters, effective capacity was less than the heat loss. Therefore, the temperature of the reactor vessel room was raised to reduce the heat loss. One-loop operation of the PHTS was able to be executed by means of these measures. The cost of electrical consumption in the power plant has been reduced by one-loop operation of the PHTS and the modification period was shortened. (authors)

  19. House-internal heating systems; Husinterna vaermesystem

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Per-Olof; Wollerstrand, Janusz [Lund Univ. (Sweden). Dept. of Heat and Power Engineering

    2005-07-01

    In this report the placement of the circulation-pump in of waterborne radiator systems, as well as their filling and deairation are investigated. The study was done by literature studies and interviews with consultants and companies active on the HVAC-market. It was concluded that different placements of the pump in relationship to the heat exchanger exist, and the arguments for the choice of placement are varying. The main explanation of the choice of placement is that it is based on experience/or by practical reasons. The most important factor influencing the placement of the pump found, was how the pump is situated in relation to the expansion-tank. To maintain pressure in the whole system the expansion-tank should be placed on the suction side of the pump without any intermediate pressure-dropping devices in between. This placement ensures overpressure in the whole radiator-system and reduces the risk of unwanted leak in of air. To avoid cavitation sufficient static pressure on the suction side of the pump is necessary. The pressure increases with the temperature, which must be taken into consideration if the pump is placed on the warm side of the heat-exchanger. From this point of view a placement in the return-pipe from the radiator-system is to be preferred. Before advices for HVAC-branch regarding placement of the circulation-pump in the heating systems can be implemented, it is of big importance to analyse and clearly specify the advantages and disadvantages of a certain placement of the pump. There is a need of directions to get house-internal systems to operate properly together with district heating system. This is especially important when older heating systems with burners and shunt valves are being connected. Filling and deairation of the radiator system is of great importance for the function of the system. A radiator-system with significant level of air remains is difficult to adjust and will not work properly. Air in the radiators leads to

  20. Heat-Resistance of the Powder Cobalt Alloys Reinforced by Niobium or Titanium Carbide

    Directory of Open Access Journals (Sweden)

    Cherepova, T.S.

    2016-01-01

    Full Text Available The characteristics of heat-resistance of powder cobalt alloys at 1100 °C were investigated. These alloys were developed for the protection of workers banding shelves GTE blades from wear. The alloys were prepared by hot pressing powders of cobalt, chromium, aluminum, iron and niobium or titanium carbides. The values of heat resistance alloys containing carbides between 30 and 70% (vol. depend on the type made of carbide alloys: alloys with titanium carbide superior in heat-resistant alloy of niobium carbide. The most significant factor affecting on the heat-resistant alloys, is porosity: with its increase the parameters decline regardless of the type and content of carbide. The optimum composition of powder heat resisting alloys of titanium carbide with a melting point above 1300 °C were determined for use in the aircraft engine.

  1. Determination and Application of Comprehensive Specific Frictional Resistance in Heating Engineering

    Directory of Open Access Journals (Sweden)

    Yanan Tian

    2018-01-01

    Full Text Available In this study, we analyze the deficiencies of specific frictional resistance in heating engineering. Based on economic specific frictional resistance, we put forward the concept of comprehensive specific frictional resistance, which considers the multiple factors of technology, economy, regulation modes, pipe segment differences, and medium pressure. Then, we establish a mathematical model of a heating network across its lifespan in order to develop a method for determining the comprehensive specific frictional resistance. Relevant conclusions can be drawn from the results. As an application, we have planned the heating engineering for Yangyuan County in China, which demonstrates the feasibility and superiority of the method.

  2. Effect Of Heat Treatment On The Corrosion Resistance Of Aluminized Steel Strips

    Directory of Open Access Journals (Sweden)

    Żaba K.

    2015-09-01

    Full Text Available The paper presents the results of corrosion resistance of heat treated aluminized steel strips. Products coated by Al-10Si alloy are used among others in a manufacturing process of welded pipes as the elements of the car exhaust systems, working in high temperatures and different environments (eg. wet, salty. The strips and tubes high performance requirements are applied to stability, thickness and roughness of Al-Si coating, adhesion and corrosion resistance. Tubes working in elements of exhaust systems in a wide range of temperatures are exposed to the effects of many aggressive factors, such as salty snow mud. It was therefore decided to carry out research on the impact of corrosion on the environmental influence on heat treated aluminized steel strips. The heat treatment was carried out temperatures in the range 250-700°C for 30, 180, 1440 minutes. Then the coatings was subjected to cyclic impact of snow mud. Total duration of treatment was 12 months and it was divided into three stages of four months and at the end of each stage was made the assessment of factor of corrosion. The results are presented in the form of macroscopic, microscopic (using a scanning electron microscope observations and the degree and type of rusty coating.

  3. Bivalent heating systems - Potential for savings through system optimisation

    International Nuclear Information System (INIS)

    Good, J.; Jenni, A.; Nussbaumer, T.

    2005-01-01

    This article tales a look at the potential for optimising bivalent heating installations for district heating systems fired with oil and wood. The influence of increases in the price of heating oil as compared to wood fuels is discussed. The authors comment that the proportion of expensive heating oil used in such installations is often too high. Price developments for both classes of fuel in 2005 are discussed. Factors influencing the proportions of oil and wood fuel used are listed and discussed, as is the mode of operation of the district heating systems, their extension and the consumers connected to them. The article provides information on the performance of 30 installations examined. Measures that can be taken to reduce the amount of heating oil used and to increase installation efficiency are presented and discussed

  4. Modeling of electric and heat processes in spot resistance welding of cross-wire steel bars

    Science.gov (United States)

    Iatcheva, Ilona; Darzhanova, Denitsa; Manilova, Marina

    2018-03-01

    The aim of this work is the modeling of coupled electric and heat processes in a system for spot resistance welding of cross-wire reinforced steel bars. The real system geometry, dependences of material properties on the temperature, and changes of contact resistance and released power during the welding process have been taken into account in the study. The 3D analysis of the coupled AC electric and transient thermal field distributions is carried out using the finite element method. The novel feature is that the processes are modeled for several successive time stages, corresponding to the change of contact area, related contact resistance, and reduction of the released power, occurring simultaneously with the creation of contact between the workpieces. The values of contact resistance and power changes have been determined on the basis of preliminary experimental and theoretical investigations. The obtained results present the electric and temperature field distributions in the system. Special attention has been paid to the temperature evolution at specified observation points and lines in the contact area. The obtained information could be useful for clarification of the complicated nature of interrelated electric, thermal, mechanical, and physicochemical welding processes. Adequate modeling is also an opportunity for proper control and improvement of the system.

  5. Heat-Flux Gage thermophosphor system

    Energy Technology Data Exchange (ETDEWEB)

    Tobin, K.W.

    1991-08-01

    This document describes the installation, hardware requirements, and application of the Heat-Flux Gage (Version 1.0) software package developed by the Oak Ridge National Laboratory, Applied Technology Division. The developed software is a single component of a thermographic phosphor-based temperature and heat-flux measurement system. The heat-flux transducer was developed by EG G Energy Measurements Systems and consists of a 1- by 1-in. polymethylpentene sheet coated on the front and back with a repeating thermographic phosphor pattern. The phosphor chosen for this application is gadolinium oxysulphide doped with terbium. This compound has a sensitive temperature response from 10 to 65.6{degree}C (50--150{degree}F) for the 415- and 490-nm spectral emission lines. 3 refs., 17 figs.

  6. Improving the performance of district heating systems by utilization of local heat boosters

    DEFF Research Database (Denmark)

    Falcone, A.; Dominkovic, D. F.; Pedersen, A. S.

    LTDH grid as they will have the strategical role of connecting the heating system with the electrical energy coming from the intermittent and fluctuating renewable energy sources such as wind and solar power. In this paper a case study of district heating system is presented and analysed. The goal......-50°C with return temperatures of 20-30 °C. This kind of heating system has many advantages and among all of them, it allows utilization of the heat coming from low exergy heat sources, as well as to decrease the grid heat losses. Electrical energy driven heat sources are also integrated into the future......District Heating (DH) plays an important role into the Danish energy green transition towards the future sustainable energy systems. The new, 4 th generation district heating network, the so called Low Temperature District Heating (LTDH), tends to lower the supply temperature of the heat down to 40...

  7. Modelling of Thermal Behavior of Borehole Heat Exchangers of Geothermal Heat Pump Heating Systems

    Directory of Open Access Journals (Sweden)

    Gornov V.F.

    2016-01-01

    Full Text Available This article reports results of comparing the accuracy of the software package “INSOLAR.GSHP.12”, modeling non-steady thermal behavior of geothermal heat pump heating systems (GHCS and of the similar model “conventional” using finite difference methods for solving spatial non-steady problems of heat conductivity. The software package is based on the method of formulating mathematical models of thermal behavior of ground low-grade heat collection systems developed by INSOLAR group of companies. Equations of mathematical model of spatial non-steady thermal behavior of ground mass of low-grade heat collection system obtained by the developed method have been solved analytically that significantly reduced computing time spent by the software complex “INSOLAR.GSHP.12” for calculations. The method allows to turn aside difficulties associated with information uncertainty of mathematical models of the ground thermal behavior and approximation of external factors affecting the ground. Use of experimentally obtained information about the ground natural thermal behavior in the software package allows to partially take into account the whole complex of factors (such as availability of groundwater, their velocity and thermal behavior, structure and arrangement of ground layers, the Earth’s thermal background, precipitation, phase transformations of moisture in the pore space, and more, significantly influencing the formation of thermal behavior of the ground mass of a low-grade geothermal heat collection system. Numerical experiments presented in the article confirmed the high convergence of the results obtained through the software package “INSOLAR.GSHP.12” with solutions obtained by conventional finite-difference methods.

  8. Exposure of heat resistant materials in a synthetic biogas

    Energy Technology Data Exchange (ETDEWEB)

    Ivarsson, Bo [Avesta Sheffield Research and Development (Sweden)

    1996-08-01

    Uncooled specimens of nine heat resistant alloys have been exposed to a gas, similar to that occurring in biomass gasification. The test temperature wax {approx} 900 deg C and the exposure time {approx} 2000 hours. The flow rate of the gas was so high that it never reached its equilibrium composition. Thermodynamical evaluations indicated that, besides oxidation, both sulphidation and carbon pick-up were possible corrosion modes. In the post test examinations, however, only oxidation could be confirmed. Most alloys were only slightly attacked, since a protective chromia rich oxide layer was formed on all specimens as a result of the low oxygen partial pressure of the gas. However, in Alloys 601 and 800, the low oxygen activity led to the formation of an internal grain boundary alumina network. 353 MA was even more severely attacked. The formation of an internal silica network seems to have initiated catastrophic oxidation attacks on several locations. This unexpected behaviour is probably a result of the sheet specimen`s being heavily cold deformed and not annealed afterwards. 11 refs, 16 figs, 2 tabs

  9. Self-healing of damage in heat resisting steels

    Science.gov (United States)

    Shinya, Norio; Kyono, Junro

    2002-11-01

    Material damage is too fine to be detected by non-destructive tests and difficult to be repaired during use. Therefore self-healing of damage is most desirable to improve the reliability of materials and structures. In heat resisting steels, creep cavities nucleate at grain boundaries by long time use at high temperatures. These creep cavities grow along grain boundaries, from grain boundary cracks by linking up each other and cause the premature and low ductility fracture. Therefore long time creep rupture life and ductility chiefly depend upon the behavior of nucleation and growth of creep cavities. If the growth of creep cavities could be suppressed, the creep rupture properties of creep rupture life and ductility should be improved due to prevention of the premature fracture. Ordinary austenitic stainless steels contain sulfur as impurity and the sulfure segregates preferentially to creep cavity surface because of its high surface actiivty. It is possible to remove sulfur almost completely by doping cerium and adding titanium to the austenitic stainless steels. By adding boron and nitrogen, boron nitride precipitates on creep cavity surface. It was thought that the boron nitride on creep cavity surface suppresses creep cavity grwoth and improve creep rupture life and ductility by its healing effect on cavities.

  10. A new class of bio-heat resisted polymer blend.

    Science.gov (United States)

    Pack, Seongchan; Kashiwagi, Takashi; Koga, Tadanori; Rafailovich, Miriam

    2009-03-01

    Increasing in oil prices and environmental concerns is a driving force to seek out alternative materials. A completely biodegradable starch is a candidate for the alternative materials. Since the starch is brittle, it must be mixed with other polymers. In order to make a thermoplastic starch (TPS), we need a bio-compatiblizer to increase a degree of compatibilization. The biocompatibilzer can be a small molecules or nanoparticles with the small molecules, which leads to improved material properties. In order to demonstrate a possible biocompatibilzer, we first developed a corn-based starch impregnated with non-halogenated flame retardant formulations. The starch was blended with Ecoflex, a biodegradable polymer. Using SAXS and USAXS we characterized structures of the compounds with different amount of Ecoflex by weight. Furthermore, the addition of 5% nanoparticles in the compounds increased the Young's Modulus and impact toughness significantly. The compounds also did flame test. It is indicated that the compound with the addition of the nanopaticles would pass with a UL-94V0 rating. Therefore, the procedure for producing these TPS compounds can be applied to any biodegradable polymers, manufacturing a new bio-heat resisted compound.

  11. Evaluation of an EMITEC resistively heated metal monolith catalytic converter on two M100 neat methanol-fueled vehicles

    Science.gov (United States)

    Piotrowski, Gregory K.; Schaefer, Ronald M.

    1992-12-01

    The report describes the evaluation of a resistively heated catalyst system on two different methanol fueled vehicles. The EMITEC catalyst consisted of a compact resistively heated metal monolith in front of a larger conventional main converter. The EMITEC catalyst was evaluated on two neat methanol-fueled vehicles, a 1981 Volkswagen Rabbit and a 1988 Toyota Corolla. Emission testing was conducted over the Federal Test Procedure (FTP) CVS-75 test cycle. The emissions of primary interest were cold start methanol (unburned fuel), carbon monoxide, and formaldehyde.

  12. A heat pipe solar collector system for winter heating in Zhengzhou city, China

    Directory of Open Access Journals (Sweden)

    Zheng Hui-Fan

    2017-01-01

    Full Text Available A heat pipe solar collector system for winter heating is investigated both experimentally and theoretically. The hourly heat collecting capacity, water temperature and contribution rate of solar collector system based on Zhengzhou city typical sunshine are calculated. The study reveals that the heat collecting capacity and water temperature increases initially and then decreases, and the solar collector system can provide from 40% to 78% heating load for a 200 m2 villa with in Zhengzhou city from November to March.

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

    Science.gov (United States)

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

    1990-01-01

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

  14. Linear heating system for measurement of thermoluminescence ...

    Indian Academy of Sciences (India)

    Unknown

    scence intensity is monitored. The theory of TL usually assumes that the sample temperature varies linearly with time, although more general theories have been formu- lated and calculations made for non-linear heating system. Previous descriptions of apparatus for the measurement of TL have been published elsewhere ...

  15. Solar Heating Systems: Progress Checks & Tests Manual.

    Science.gov (United States)

    Green, Joanne; And Others

    This manual contains Progress Checks and Tests for use in a Solar Heating Systems curriculum (see note). It contains master copies of all Progress Checks and Unit Tests accompanying the curriculum, organized by unit. (The master copies are to be duplicated by each school so that adequate copies are available for student use in a self-paced student…

  16. Characterization of a solar photovoltaic/loop-heat-pipe heat pump water heating system

    International Nuclear Information System (INIS)

    Zhang, Xingxing; Zhao, Xudong; Xu, Jihuan; Yu, Xiaotong

    2013-01-01

    Highlights: ► Describing concept and operating principle of the PV/LHP heat pump water heating system. ► Developing a numerical model to evaluate the performance of the system. ► Experimental testing of the prototype system. ► Characterizing the system performance using parallel comparison between the modelling and experimental results. ► Investigating the impact of the operating conditions to the system’s performance. -- Abstract: This paper introduced the concept, potential application and benefits relating to a novel solar photovoltaic/loop-heat-pipe (PV/LHP) heat pump system for hot water generation. On this basis, the paper reported the process and results of characterizing the performance of such a system, which was undertaken through dedicated thermo-fluid and energy balance analyses, computer model development and operation, and experimental verification and modification. The fundamental heat transfer, fluid flow and photovoltaic governing equations were applied to characterize the energy conversion and transfer processes occurring in each part and whole system layout; while the energy balance approach was utilized to enable inter-connection and resolution of the grouped equations. As a result, a dedicated computer model was developed and used to calculate the operational parameters, optimise the geometrical configurations and sizes, and recommend the appropriate operational condition relating to the system. Further, an experimental rig was constructed and utilized to acquire the relevant measurement data that thus enabled the parallel comparison between the simulation and experiment. It is concluded that the testing and modelling results are in good agreement, indicating that the model has the reasonable accuracy in predicting the system’s performance. Under the given experimental conditions, the electrical, thermal and overall efficiency of the PV/LHP module were around 10%, 40% and 50% respectively; whilst the system’s overall performance

  17. Cooperative heat transfer and ground coupled storage system

    Science.gov (United States)

    Metz, P.D.

    A cooperative heat transfer and ground coupled storage system wherein collected solar heat energy is ground stored and permitted to radiate into the adjacent ground for storage therein over an extended period of time when such heat energy is seasonally maximally available. Thereafter, when said heat energy is seasonally minimally available and has propagated through the adjacent ground a substantial distance, the stored heat energy may be retrieved by a circumferentially arranged heat transfer means having a high rate of heat transfer.

  18. Investigations of Intelligent Solar Heating Systems for Single Family House

    DEFF Research Database (Denmark)

    Andersen, Elsa; Chen, Ziqian; Fan, Jianhua

    2014-01-01

    Three differently designed intelligent solar heating systems are investigated experimentally in a test facility. The systems provide all the needed yearly heating demand in single family houses. The systems are based on highly stratified tanks with variable auxiliary heated volumes. The tank...... is a tank in tank heat storage with domestic hot water in the inner tank and space heating water in the outer tank. The total tank volume is 750 liters and the solar collector area is 9 m2. The auxiliary energy supply system is based on electrical heating element(s)/heat pump and is different for all three...... systems.The system will be equipped with an intelligent control system where the control of the electrical heating element(s)/heat pump is based on forecasts of the variable electricity price, the heating demand and the solar energy production.By means of numerical models of the systems made in Trnsys...

  19. Efficiency of the heat pump cooperating with various heat sources in monovalent and bivalent systems

    Energy Technology Data Exchange (ETDEWEB)

    Kurpaska, S.; Latala, H. [Krakow Univ. of Agriculture, Krakow (Poland). Inst. of Agricultural Engineering and Computer Science

    2010-07-01

    This paper reported on a study that tested the efficiency of compressor heat pumps cooperating with various types of lower heat sources such as horizontal ground heat exchangers, vertical exchangers and sources operating in the bivalent system. The system for receiving energy consisted of a traditional heating system and liquid-air exchangers. The study identified a strong relationship between the heating efficiency of the analysed systems and temperature inside the structure. The study showed that the bivalent system was fully capable of meeting a heat requirement of about 1 MJ -2.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  1. Miniature Heat Transport System for Nanosatellite Technology

    Science.gov (United States)

    Douglas, Donya M,

    1999-01-01

    The scientific understanding of key physical processes between the Sun and the Earth require simultaneous measurements from many vantage points in space. Nano-satellite technologies will enable a class of constellation missions for the NASA Space Science Sun-Earth Connections. This recent emphasis on the implementation of smaller satellites leads to a requirement for development of smaller subsystems in several areas. Key technologies under development include: advanced miniaturized chemical propulsion; miniaturized sensors; highly integrated, compact electronics; autonomous onboard and ground operations; miniatures low power tracking techniques for orbit determination; onboard RF communications capable of transmitting data to the ground from far distances; lightweight efficient solar array panels; lightweight, high output battery cells; lightweight yet strong composite materials for the nano-spacecraft and deployer-ship structures. These newer smaller systems may have higher power densities and higher thermal transport requirements than seen on previous small satellites. Furthermore, the small satellites may also have a requirement to maintain thermal control through extended earth shadows, possibly up to 8 hours long. Older thermal control technology, such as heaters, thermostats, and heat pipes, may not be sufficient to meet the requirements of these new systems. Conversely, a miniature two-phase heat transport system (Mini-HTS) such as a Capillary Pumped Loop (CPL) or Loop Heat Pipe (LBP) is a viable alternative. A Mini-HTS can provide fine temperature control, thermal diode action, and a highly efficient means of heat transfer. The Mini-HTS would have power capabilities in the range of tens of watts or less and provide thermal control over typical spacecraft ranges. The Mini-HTS would allow the internal portion of the spacecraft to be thermally isolated from the external radiator, thus protecting the internal components from extreme cold temperatures during an

  2. Heat-resistant agent used for control sand of steam huff and puff heavy oil well

    Science.gov (United States)

    Zhang, F. S.; Liu, G. L.; Lu, Y. J.; Xiong, X. C.; Ma, J. H.; Su, H. M.

    2018-01-01

    Heat-resistant agent containing hydroxymethyl group was synthesized from coal tar, which has similar structure with phenolic resin and could improve the heat resistance of phenolic resin sand control agent. The results showed that the heat resistance of the sand control agent was improved by adding 10% to 30% heat-resistant agent, after 280°C high temperature treatment for 7d, the compressive strength of consolidated core was increased to more than 5MPa. The compressive strength of consolidation core was not decreased after immersion in formation water, crude oil, acid or alkaline medium, which showed good resistance to medium immersion. The sand control agent had small core damage and the core permeability damage ratio of sand control agent consolidation was only 18.7%.

  3. Heat control in HVDC resistive divider by PID and NN controllers

    International Nuclear Information System (INIS)

    Yilmaz, S.; Dincer, H.; Eksin, I.; Kalenderli, O.

    2007-01-01

    In this study, a control system is presented that is devised to increase measurement precisions within a prototype high voltage DC resistive divider (HVDC-RD). Since one of the major sources of measurement errors in such devices is the self heating effect, a system controlling the temperature within the high voltage DC resistive divider is devised so that suitable and stable temperature conditions are maintained that, in return, will decrease the measurement errors. The resistive divider system is cooled by oil, and PID and neural network (NN) controllers try to keep the temperature within the prescribed limits. The system to be controlled exhibits a nonlinear character, and therefore, a control approach based on NN controllers is proposed. Thus, a system that can fulfill the various requirements dictated by the designer is constructed. The performance of the NN controller is compared with that of the PID controller developed for the same purpose, and the values of the performance indices indicate the superiority of the NN controller over that of the classical PID controller

  4. A mobile genetic element profoundly increases heat resistance of bacterial spores.

    Science.gov (United States)

    Berendsen, Erwin M; Boekhorst, Jos; Kuipers, Oscar P; Wells-Bennik, Marjon H J

    2016-11-01

    Bacterial endospores are among the most resilient forms of life on earth and are intrinsically resistant to extreme environments and antimicrobial treatments. Their resilience is explained by unique cellular structures formed by a complex developmental process often initiated in response to nutrient deprivation. Although the macromolecular structures of spores from different bacterial species are similar, their resistance to environmental insults differs widely. It is not known which of the factors attributed to spore resistance confer very high-level heat resistance. Here, we provide conclusive evidence that in Bacillus subtilis, this is due to the presence of a mobile genetic element (Tn1546-like) carrying five predicted operons, one of which contains genes that encode homologs of SpoVAC, SpoVAD and SpoVAEb and four other genes encoding proteins with unknown functions. This operon, named spoVA 2mob , confers high-level heat resistance to spores. Deletion of spoVA 2mob in a B. subtilis strain carrying Tn1546 renders heat-sensitive spores while transfer of spoVA 2mob into B. subtilis 168 yields highly heat-resistant spores. On the basis of the genetic conservation of different spoVA operons among spore-forming species of Bacillaceae, we propose an evolutionary scenario for the emergence of extremely heat-resistant spores in B. subtilis, B. licheniformis and B. amyloliquefaciens. This discovery opens up avenues for improved detection and control of spore-forming bacteria able to produce highly heat-resistant spores.

  5. An optimisation framework for thermal energy storage integration in a residential heat pump heating system

    International Nuclear Information System (INIS)

    Renaldi, R.; Kiprakis, A.; Friedrich, D.

    2017-01-01

    Highlights: • An integrated framework for the optimal design of low carbon heating systems. • Development of a synthetic heat demand model with occupancy profiles. • Linear model of a heat pump with thermal energy storage heating system. • Evaluation of domestic heating system from generally available input parameters. • The lower carbon heating system can be cost competitive with conventional systems. - Abstract: Domestic heating has a large share in the UK total energy consumption and significant contribution to the greenhouse gas emissions since it is mainly fulfilled by fossil fuels. Therefore, decarbonising the heating system is essential and an option to achieve this is by heating system electrification through heat pumps (HP) installation in combination with renewable power generation. A potential increase in performance and flexibility can be achieved by pairing HP with thermal energy storage (TES), which allows the shifting of heat demand to off peak periods or periods with surplus renewable electricity. We present a design and operational optimisation model which is able to assess the performance of HP–TES relative to conventional heating systems. The optimisation is performed on a synthetic heat demand model which requires only the annual heat demand, temperature and occupancy profiles. The results show that the equipment and operational cost of a HP system without TES are significantly higher than for a conventional system. However, the integration of TES and time-of-use tariffs reduce the operational cost of the HP systems and in combination with the Renewable Heating Incentive make the HP systems cost competitive with conventional systems. The presented demand model and optimisation procedure will enable the design of low carbon district heating systems which integrate the heating system with the variable renewable electricity supply.

  6. The resistance of surfaces treated with oils and waxes to the action of dry heat

    Directory of Open Access Journals (Sweden)

    Jaić Milan

    2009-01-01

    Full Text Available Surface treatment of wood can be done with different coatings, and the choice of the appropriate system of processing depends on several factors, such as technological, aesthetic, economic and ecological. Raising awareness of the need to preserve the living and working environment has had a crucial impact on the increase in the use of natural materials for surface treatment of wood - oil and wax. The application of oils and waxes allows surface treated wood to keep the natural look, while protecting it from different influences, which can cause degradation and deterioration of the final product. The paper presents the results of testing the resistance of beech surface (Fagus silvatica L. processed with linseed oil and beeswax to the action of dry heat. In order to compare the quality of surface treated with oil and/or wax, beech wood treated with 2K-polyurethane coating is taken as a reference of surface treatment of wood. Surfaces treated with beeswax are less resistant to dry heat than those treated with linseed oil, and both showed significantly less resistance than surface treated with 2K-polyurethane coating.

  7. District heating and heat storage using the solution heat of an ammonia/water system

    International Nuclear Information System (INIS)

    Taube, M.; Peier, W.; Mayor, J.C.

    1976-01-01

    The article describes a model for the optimum use of the heat energy generated in a nuclear power station for district heating and heat storage taking account of the electricity and heat demand varying with time. (HR/AK) [de

  8. Solar Water Heating System for Biodiesel Production

    Science.gov (United States)

    Syaifurrahman; Usman, A. Gani; Rinjani, Rakasiwi

    2018-02-01

    Nowadays, electricity become very expensive thing in some remote areas. Energy from solar panels give the solution as renewable energy that is environment friendly. West Borneo is located on the equator where the sun shines for almost 10-15 hours/day. Solar water heating system which is includes storage tank and solar collections becomes a cost-effective way to generate the energy. Solar panel heat water is delivered to water in storage tank. Hot water is used as hot fluid in biodiesel jacked reactor. The purposes of this research are to design Solar Water Heating System for Biodiesel Production and measure the rate of heat-transfer water in storage tank. This test has done for 6 days, every day from 8.30 am until 2.30 pm. Storage tank and collection are made from stainless steel and polystyrene a well-insulated. The results show that the heater can be reach at 50ºC for ±2.5 hours and the maximum temperature is 62ºC where the average of light intensity is 1280 lux.

  9. L- and U-shaped heat pipes thermal modules with twin fans for cooling of electronic system under variable heat source areas

    Science.gov (United States)

    Wang, Jung-Chang

    2014-04-01

    This study utilizes a versatile superposition method with thermal resistance network analysis to design and experiment on a thermal module with embedded six L-shaped or two U-shaped heat pipes and plate fins under different fan speeds and heat source areas. This type of heat pipes-heat sink module successively transfer heat capacity from a heat source to the heat pipes, the heat sink and their surroundings, and are suitable for cooling electronic systems via forced convection mechanism. The thermal resistances contain all major components from the thermal interface through the heat pipes and fins. Thermal performance testing shows that the lowest thermal resistances of the representative L- and U-shaped heat pipes-heat sink thermal modules are respectively 0.25 and 0.17 °C/W under twin fans of 3,000 RPM and 30 × 30 mm2 heat sources. The result of this work is a useful thermal management method to facilitate rapid analysis.

  10. Heat-pipe heat transport system for Stirling space power converter

    Science.gov (United States)

    Alger, Donald L.

    Life issues relating to a sodium-heat-pipe heat transport system are discussed. The heat-pipe system provides heat, at a temperature of 1050 K, to a 50-kWe Stirling engine/linear alternator power converter called the Stirling space power converter. Because corrosion of heat-pipe materials in contact with sodium can affect the life of the heat pipe, a literature review of sodium corrosion processes was performed. It was found that impurity reactions, primarily oxygen, and dissolution of alloy elements were the two corrosion processes likely to be operative in the heat pipe. Approaches that are being taken to minmize these corrosion processes are discussed.

  11. Solar system for domestic hot water and space heating

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, W. [Arbeitsgemeinschaf Erneubare Energie, Gleisdorf (Austria)

    1997-12-31

    The solar thermal markets, different types of solar systems for hot water and space heating, the dimensioning and the components of solar heating systems, the properties of the systems are reviewed in this presentation

  12. Ecological optimization of an irreversible quantum Carnot heat engine with spin-1/2 systems

    International Nuclear Information System (INIS)

    Liu Xiaowei; Chen Lingen; Wu Feng; Sun Fengrui

    2010-01-01

    A model of a quantum heat engine with heat resistance, internal irreversibility and heat leakage and many non-interacting spin-1/2 systems is established in this paper. The quantum heat engine cycle is composed of two isothermal processes and two irreversible adiabatic processes and is referred to as a spin quantum Carnot heat engine. Based on the quantum master equation and the semi-group approach, equations of some important performance parameters, such as power output, efficiency, entropy generation rate and ecological function (a criterion representing the optimal compromise between exergy output rate and exergy loss rate), for the irreversible spin quantum Carnot heat engine are derived. The optimal ecological performance of the heat engine in the classical limit is analyzed with numerical examples. The effects of internal irreversibility and heat leakage on ecological performance are discussed in detail.

  13. Estimating the Condition of the Heat Resistant Lining in an Electrical Reduction Furnace

    Directory of Open Access Journals (Sweden)

    Jan G. Waalmann

    1988-01-01

    Full Text Available This paper presents a system for estimating the condition of the heat resistant lining in an electrical reduction furnace for ferrosilicon. The system uses temperature measured with thermocouples placed on the outside of the furnace-pot. These measurements are used together with a mathematical model of the temperature distribution in the lining in a recursive least squares algorithm to estimate the position of 'the transformation front'. The system is part of a monitoring system which is being developed in the AIP-project: 'Condition monitoring of strongly exposed process equipment in thc ferroalloy industry'. The estimator runs on-line, and results arc presented in colour-graphics on a display unit. The goal is to locate the transformation front with an accuracy of +- 5cm.

  14. Resistively-Heated Microlith-based Adsorber for Carbon Dioxide and Trace Contaminant Removal

    Science.gov (United States)

    Roychoudhury, S.; Walsh, D.; Perry, J.

    2005-01-01

    An integrated sorber-based Trace Contaminant Control System (TCCS) and Carbon Dioxide Removal Assembly (CDRA) prototype was designed, fabricated and tested. It corresponds to a 7-person load. Performance over several adsorption/regeneration cycles was examined. Vacuum regenerations at effective time/temperature conditions, and estimated power requirements were experimentally verified for the combined CO2/trace contaminant removal prototype. The current paper details the design and performance of this prototype during initial testing at CO2 and trace contaminant concentrations in the existing CDRA, downstream of the drier. Additional long-term performance characterization is planned at NASA. Potential system design options permitting associated weight, volume savings and logistic benefits, especially as relevant for long-duration space flight, are reviewed. The technology consisted of a sorption bed with sorbent- coated metal meshes, trademarked and patented as Microlith by Precision Combustion, Inc. (PCI). By contrast the current CO2 removal system on the International Space Station employs pellet beds. Preliminary bench scale performance data (without direct resistive heating) for simultaneous CO2 and trace contaminant removal was reviewed in SAE 2004-01-2442. In the prototype, the meshes were directly electrically heated for rapid response and accurate temperature control. This allowed regeneration via resistive heating with the potential for shorter regeneration times, reduced power requirement, and net energy savings vs. conventional systems. A novel flow arrangement, for removing both CO2 and trace contaminants within the same bed, was demonstrated. Thus, the need for a separate trace contaminant unit was eliminated resulting in an opportunity for significant weight savings. Unlike the current disposable charcoal bed, zeolites for trace contaminant removal are amenable to periodic regeneration.

  15. Energy Savings for Solar Heating Systems

    DEFF Research Database (Denmark)

    Thür, Alexander; Furbo, Simon; Shah, Louise Jivan

    2006-01-01

    showed a good degree of similarity. With the boiler model, various simulations of solar domestic hot water heating systems were done for different hot water demands and collector sizes. The result shows that the potential of fuel reduction can be much higher than the solar gain of the solar thermal...... system. For some conditions the fuel reduction can be up to the double of the solar gain due to a strong increase of the system efficiency. As the monitored boilers were not older than 3 years, it can be assumed that the saving potential with older boilers could be even higher than calculated...

  16. Quantifying variety-specific heat resistance and the potential for adaptation to climate change.

    Science.gov (United States)

    Tack, Jesse; Barkley, Andrew; Rife, Trevor W; Poland, Jesse A; Nalley, Lawton Lanier

    2016-08-01

    The impact of climate change on crop yields has become widely measured; however, the linkages for winter wheat are less studied due to dramatic weather changes during the long growing season that are difficult to model. Recent research suggests significant reductions under warming. A potential adaptation strategy involves the development of heat resistant varieties by breeders, combined with alternative variety selection by producers. However, the impact of heat on specific wheat varieties remains relatively unstudied due to limited data and the complex genetic basis of heat tolerance. Here, we provide a novel econometric approach that combines field-trial data with a genetic cluster mapping to group wheat varieties and estimate a separate extreme heat impact (temperatures over 34 °C) across 24 clusters spanning 197 varieties. We find a wide range of heterogeneous heat resistance and a trade-off between average yield and resistance. Results suggest that recently released varieties are less heat resistant than older varieties, a pattern that also holds for on-farm varieties. Currently released - but not yet adopted - varieties do not offer improved resistance relative to varieties currently grown on farm. Our findings suggest that warming impacts could be significantly reduced through advances in wheat breeding and/or adoption decisions by producers. However, current adaptation-through-adoption potential is limited under a 1 °C warming scenario as increased heat resistance cannot be achieved without a reduction in average yields. © 2015 John Wiley & Sons Ltd.

  17. WASTE HEAT RECOVERY IN HEAT PUMP SYSTEMS: SOLUTION TO REDUCE GLOBAL WARMING

    Directory of Open Access Journals (Sweden)

    Y. Baradey

    2015-11-01

    Full Text Available Energy conversion technologies, where waste heat recovery systems are included, have received significant attention in recent years due to reasons that include depletion of fossil fuel, increasing oil prices, changes in climatic conditions, and global warming. For low temperature applications, there are many sources of thermal waste heat, and several recovery systems and potential useful applications have been proposed by researchers [1-4]. In addition, many types of equipment are used to recover waste thermal energy from different systems at low, medium, and high temperature applications, such as heat exchangers, waste heat recovery boiler, thermo-electric generators, and recuperators. In this paper, the focus is on waste heat recovery from air conditioners, and an efficient application of these energy resources. Integration of solar energy with heat pump technologies and major factors that affect the feasibility of heat recovery systems have been studied and reviewed as well. KEYWORDS: waste heat recovery; heat pump.

  18. Optimal Ground Source Heat Pump System Design

    Energy Technology Data Exchange (ETDEWEB)

    Ozbek, Metin [Environ Holdings Inc., Princeton, NJ (United States); Yavuzturk, Cy [Univ. of Hartford, West Hartford, CT (United States); Pinder, George [Univ. of Vermont, Burlington, VT (United States)

    2015-04-01

    Despite the facts that GSHPs first gained popularity as early as the 1940’s and they can achieve 30 to 60 percent in energy savings and carbon emission reductions relative to conventional HVAC systems, the use of geothermal energy in the U.S. has been less than 1 percent of the total energy consumption. The key barriers preventing this technically-mature technology from reaching its full commercial potential have been its high installation cost and limited consumer knowledge and trust in GSHP systems to deliver the technology in a cost-effective manner in the market place. Led by ENVIRON, with support from University Hartford and University of Vermont, the team developed and tested a software-based a decision making tool (‘OptGSHP’) for the least-cost design of ground-source heat pump (‘GSHP’) systems. OptGSHP combines state of the art optimization algorithms with GSHP-specific HVAC and groundwater flow and heat transport simulation. The particular strength of OptGSHP is in integrating heat transport due to groundwater flow into the design, which most of the GSHP designs do not get credit for and therefore are overdesigned.

  19. The research of heating efficiency of different induction heating systems

    Directory of Open Access Journals (Sweden)

    Konesev Sergey

    2017-01-01

    Full Text Available Computer models of tape and coil inductors are described, and a comparison of the heating efficiency depending on various parameters is made. The developed computer model was made in the ELCUT 6.0. As a result of the simulation, data on the heating characteristics (depending on the various parameters of the heating elements are obtained. The average statistical data of a series of experiments with a tape inductor are given. It is shown that for the same parameters (values of inductance and number of wires, the tape version inductor heats up a pipe to a higher temperature (by 5.08% than the inductor in the coil version in 10 minutes.

  20. Polyphasic taxonomy of the heat resistant ascomycete genus Byssochlamys and its Paecilomyces anamorphs

    NARCIS (Netherlands)

    Samson, R.A.; Houbraken, J.; Varga, J.; Frisvad, J.C.

    2009-01-01

    Byssochlamys and related Paecilomyces strains are often heat resistant and may produce mycotoxins in contaminated pasteurised foodstuffs. A comparative study of all Byssochlamys species was carried out using a polyphasic approach to find characters that differentiate species and to establish

  1. A study on heat transfer through the fin-wick structure mounted in the evaporator for a plate loop heat pipe system

    International Nuclear Information System (INIS)

    Nguyen, Xuan Hung; Sung, Byung Ho; Choi, Jee Hoon; Kim, Chul Ju; Yoo, Jung Hyung; Seo, Min Whan

    2008-01-01

    This paper investigates the plate loop heat pipe system with an evaporator mounted with fin-wick structure to dissipate effectively the heat generated by the electronic components. The heat transfer formulation is modeled and predicted through thermal resistance analysis of the fin-wick structure in the evaporator. The experimental approach measures the thermal resistances and the operating characteristics. These results gathered in this investigation have been used to the objective of the information to improve the LHP system design so as to apply as the future cooling devices of the electronic components

  2. Impact of Next Generation District Heating Systems on Distribution Network Heat Losses: A Case Study Approach

    Science.gov (United States)

    Li, Yu; Rezgui, Yacine

    2018-01-01

    District heating (DH) is a promising energy pathway to alleviate environmental negative impacts induced by fossil fuels. Improving the performance of DH systems is one of the major challenges facing its wide adoption. This paper discusses the heat losses of the next generation DH based on the constructed Simulink model. Results show that lower distribution temperature and advanced insulation technology greatly reduce network heat losses. Also, the network heat loss can be further minimized by a reduction of heat demand in buildings.

  3. Developmental acclimation to low or high humidity conditions affect starvation and heat resistance of Drosophila melanogaster.

    Science.gov (United States)

    Parkash, Ravi; Ranga, Poonam; Aggarwal, Dau Dayal

    2014-09-01

    Several Drosophila species originating from tropical humid localities are more resistant to starvation and heat stress than populations from high latitudes but mechanistic bases of such physiological changes are largely unknown. In order to test whether humidity levels affect starvation and heat resistance, we investigated developmental acclimation effects of low to high humidity conditions on the storage and utilization of energy resources, body mass, starvation survival, heat knockdown and heat survival of D. melanogaster. Isofemale lines reared under higher humidity (85% RH) stored significantly higher level of lipids and showed greater starvation survival hours but smaller in body size. In contrast, lines reared at low humidity evidenced reduced levels of body lipids and starvation resistance. Starvation resistance and lipid storage level were higher in females than males. However, the rate of utilization of lipids under starvation stress was lower for lines reared under higher humidity. Adult flies of lines reared at 65% RH and acclimated under high or low humidity condition for 200 hours also showed changes in resistance to starvation and heat but such effects were significantly lower as compared with developmental acclimation. Isofemale lines reared under higher humidity showed greater heat knockdown time and heat-shock survival. These laboratory observations on developmental and adult acclimation effects of low versus high humidity conditions have helped in explaining seasonal changes in resistance to starvation and heat of the wild-caught flies of D. melanogaster. Thus, we may suggest that wet versus drier conditions significantly affect starvation and heat resistance of D. melanogaster. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Shutter heating system of Antarctic bright star survey telescope

    Science.gov (United States)

    Chen, Jie; Dong, Shucheng; Jiang, Fengxin; Zhang, Hongfei; Wang, Jian

    2016-07-01

    A heat preservation system for mechanical shutter in Antarctic is introduced in the paper. The system consists of the heat preservation chamber, the host controller STM32F103C8T6 with peripheral circuit and the control algorithm. The whole design is carried out on the basis of the low temperature requirement, including the cavity structure and thermal insulation. The heat preservation chamber is used to keep the shutter warm and support the weight of the camera. Using PT100 as the temperature sensor, the signal processing circuit converts the temperature to the voltage which is then digitized by the 12 bit ADC in the STM32. The host controller transforms the voltage data into temperature, and through the tuning of the Fussy PID algorithm which controls the duty cycle of the MOSFET, the temperature control of chamber is realized. The System has been tested in the cryogenic environment for a long time, with characteristic of low temperature resistance, small volume, high accuracy of temperature control as well as remote control and detection.

  5. Effect of Ultrasonic Waves on the Heat Resistance of Bacillus cereus and Bacillus licheniformis Spores

    Science.gov (United States)

    Burgos, J.; Ordóñez, J. A.; Sala, F.

    1972-01-01

    Heat resistance of Bacillus cereus and Bacillus licheniformis spores in quarter-strength Ringer solution decreases markedly after ultrasonic treatments which are unable to kill a significant proportion of the spore population. This effect does not seem to be caused by a loss of Ca2+ or dipicolinic acid. The use of ultrasonics to eliminate vegetative cells or to break aggregates in Bacillus spore suspensions to be used subsequently in heat resistance experiments appears to be unadvisable. PMID:4627969

  6. Evaluation of resistance gene transfer from heat-treated Escherichia coli.

    Science.gov (United States)

    Le Devendec, Laëtitia; Jouy, Eric; Kempf, Isabelle

    2018-04-02

    Antimicrobial-resistant Escherichia coli may be present in various foods. The aim of this study was to evaluate the impact of heat treatment, simulating food preparation, on the possibility of antimicrobial resistance genes being transferred from E. coli cells. The study was performed on antimicrobial-resistant E. coli cells in suspension in a sterile saline solution. The stability of resistance genes and the possibility of their transfer by transformation or conjugation were analyzed. Results showed that antimicrobial-resistant E. coli cells managing to survive after a few minutes at 60 °C retained their antimicrobial resistance. No plasmid could be transferred by conjugation from antimicrobial-resistant E. coli cells heated to 60 °C for ten or more minutes. Twelve electroporation experiments were performed using a bacterial suspension heated to 70 °C for 30 min. Genes coding for resistance to extended-spectrum cephalosporins, tetracycline or sulfonamides were transferred to an E. coli DH5α recipient on two occasions. In conclusion we showed that heat-treated E. coli may occasionally transfer resistance genes. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Small-Scale Pellet Heating Systems from Consumer Perspective

    International Nuclear Information System (INIS)

    Mahapatra, K.; Gustavsson, L.

    2006-01-01

    A questionnaire survey of 1,500 detached house owners was carried out in the autumn of 2004 to find out the factors influencing the adoption and diffusion of pellet heating systems in the Swedish residential sector. The results revealed that most of the respondents had no plans to install new heating systems as they were satisfied with their existing ones. Economic aspects and functional reliability were the most important factors in the respondents' choice of heating system while environmental factors were of less importance. Therefore, internalizing external costs, such as environmental costs, might be effective in influencing house owners to adopt environmentally benign heating systems. Installers were the most important source of information on heating systems. Hence, it is important that they could inform the consumers comprehensively and accurately about different heating systems. Respondents perceived the relative advantage of pellet boilers over oil or electricity-based heating systems, but bedrock heat pump system was ranked higher than pellet heating system in every aspect except for investment cost. Pellet heating system has advantage over district heating system with respect to investment cost and annual cost of heating. District heating system was considered as most functionally reliable and automatic

  8. Optimal heat rejection pressure in transcritical carbon dioxide air conditioning and heat pump systems

    DEFF Research Database (Denmark)

    Liao, Shengming; Jakobsen, Arne

    1998-01-01

    Due to the urgent need for environmentally benign refrigerants, the use of the natural substance carbon dioxide in refrigeration systems has gained more and more attention. In systems such as automobile air-conditioners and heat pumps, owing to the relatively high heat rejection temperatures, the...... dioxide air conditioning or heat pump systems and for intelligent controlling such systems.......Due to the urgent need for environmentally benign refrigerants, the use of the natural substance carbon dioxide in refrigeration systems has gained more and more attention. In systems such as automobile air-conditioners and heat pumps, owing to the relatively high heat rejection temperatures......, the cycles using carbon dioxide as refrigerant will have to operate in the transcritical area. In a transcritical carbon dioxide system, there is an optimal heat rejection pressure that gives a maximum COP. In this paper, it is shown that the value of this optimal heat rejection pressure mainly depends...

  9. Simulation of Radiation Heat Transfer in a VAR Furnace Using an Electrical Resistance Network

    Science.gov (United States)

    Ballantyne, A. Stewart

    The use of electrical resistance networks to simulate heat transfer is a well known analytical technique that greatly simplifies the solution of radiation heat transfer problems. In a VAR furnace, radiative heat transfer occurs between the ingot, electrode, and crucible wall; and the arc when the latter is present during melting. To explore the relative heat exchange between these elements, a resistive network model was developed to simulate the heat exchange between the electrode, ingot, and crucible with and without the presence of an arc. This model was then combined with an ingot model to simulate the VAR process and permit a comparison between calculated and observed results during steady state melting. Results from simulations of a variety of alloys of different sizes have demonstrated the validity of the model. Subsequent simulations demonstrate the application of the model to the optimization of both steady state and hot top melt practices, and raises questions concerning heat flux assumptions at the ingot top surface.

  10. Systemic resistance induced by rhizosphere bacteria

    OpenAIRE

    Loon, L.C. van; Bakker, P.A.H.M.; Pieterse, C.M.J.

    1998-01-01

    Nonpathogenic rhizobacteria can induce a systemic resistance in plants that is phenotypically similar to pathogen-induced systemic acquired resistance (SAR). Rhizobacteria-mediated induced systemic resistance (ISR) has been demonstrated against fungi, bacteria, and viruses in Arabidopsis, bean, carnation, cucumber, radish, tobacco, and tomato under conditions in which the inducing bacteria and the challenging pathogen remained spatially separated. Bacterial strains differ in their ability to ...

  11. Integration of large-scale heat pumps in the district heating systems of Greater Copenhagen

    DEFF Research Database (Denmark)

    Bach, Bjarne; Werling, Jesper; Ommen, Torben Schmidt

    2016-01-01

    This study analyses the technical and private economic aspects of integrating a large capacity of electric driven HP (heat pumps) in the Greater Copenhagen DH (district heating) system, which is an example of a state-of-the-art large district heating system with many consumers and suppliers...

  12. Solar heating system final design package

    Science.gov (United States)

    1979-01-01

    The system is composed of a warm air collector, a logic control unit and a universal switching and transport unit. The collector was originally conceived and designed as an integrated roof/wall system and therefore provides a dual function in the structure. The collector serves both as a solar energy conversion system and as a structural weather resistant skin. The control unit provides totally automatic control over the operation of the system. It receives input data from sensor probes in collectors, storage and living space. The logic was designed so as to make maximum use of solar energy and minimize use of conventional energy. The transport and switching unit is a high-efficiency air-handling system equipped with gear motor valves that respond to outputs from the control system. The fan unit was designed for maximum durability and efficiency in operation, and has permanently lubricated ball bearings and excellent air-handling efficiency.

  13. Energy Efficient Waste Heat Recovery from an Engine Exhaust System

    Science.gov (United States)

    2016-12-01

    AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE ENERGY EFFICIENT WASTE HEAT RECOVERY FROM AN ENGINE EXHAUST SYSTEM 5. FUNDING NUMBERS 6...release. Distribution is unlimited. ENERGY EFFICIENT WASTE HEAT RECOVERY FROM AN ENGINE EXHAUST SYSTEM Aaron R. VanDenBerg Lieutenant, United...HEAT RECOVERY DEVICES Ships mainly extract heat and energy from exhaust gases by using a waste heat boiler located in the actual exhaust duct. The

  14. Innovative system for delivery of low temperature district heating

    OpenAIRE

    Ianakiev, A; Cui, JM; Garbett, S; Filer, A

    2017-01-01

    An innovative low temperature district heating (LTDH) local network is developed in Nottingham, supported by the REMOURBAN project, part of the H2020 Smart City and Community Lighthouse scheme. It was proposed that a branch emanating from the return pipe of the existing district heating system in Nottingham would be created to use low temperature heating for the first time on such scale in the UK. The development is aimed to extract unused heat from existing district heating system and to mak...

  15. Improved corrosion resistance of aluminum brazing sheet by a post-brazing heat treatment

    NARCIS (Netherlands)

    Norouzi Afshar, F.; Tichelaar, F.D.; Glenn, A. M.; Taheri, P.; Sababi, M.; Terryn, H.A.; Mol, J.M.C.

    2017-01-01

    This work studies the influence of the microstructure on the corrosion mechanism and susceptibility of as-brazed aluminum sheet. Various microstructures are obtained using postbrazing heat treatments developed to enhance the corrosion resistance of an AA4xxx/AA3xxx brazing sheet. The heat

  16. Individual Heating systems vs. District Heating systems: What will consumers pay for convenience?

    International Nuclear Information System (INIS)

    Yoon, Taeyeon; Ma, Yongsun; Rhodes, Charles

    2015-01-01

    For Korea's two most popular apartment heating systems – Individual Heating (IH) and District Heating (DH), – user convenience rests heavily on location of the boiler, availability of hot water, administration of the system, and user control of indoor temperature. A double-bounded dichotomous choice method estimates consumer value for convenience, in a hypothetical market. Higher-income more-educated consumers in more expensive apartments prefer DH. Cost-conscious consumers, who use more electrical heating appliances and more actively adjust separate room temperatures, prefer IH. With willingness-to-pay (WTP) defined as the price ratio between IH and DH, 800 survey respondents indicate a WTP of 4.0% for DH over IH. IH users unfamiliar with DH expect little greater convenience (0.1% WTP), whereas the WTP for DH users runs to 7.9%, demonstrating consumer loyalty. Quantified estimates of consumer preference and convenience can inform design of a full-cost-plus pricing system with a price cap. Results here indirectly predict the effect of abolishing regulations that exclusively establish district heating zones. Strategies to foster the many external benefits of DH systems should stress not their lower cost, but convenience, comfort, and safety. Higher installation costs still hamper DH expansion, so policy-makers could set policies to lower cost barriers to entry. - Highlights: • District Heating (DH) and Individual Heating (IH) systems differ in user convenience. • Difference of convenience is evaluated by a double-bounded dichotomous choice method. • Consumers are willing to pay a 4.03–12.52% higher rate to use DH rather than IH. • Consumers with high living standards prefer DH to IH, and show high consumer loyalty. • Strategies to foster DH systems should stress DH convenience over its lower cost.

  17. Heat Saving Strategies in Sustainable Smart Energy Systems

    Directory of Open Access Journals (Sweden)

    Henrik Lund

    2014-06-01

    Full Text Available This paper investigates to which extent heat should be saved rather than produced and to which extent district heating infrastructures, rather than individual heating solutions, should be used in future sustainable smart energy systems. Based on a concrete proposal to implement the Danish governmental 2050 fossil-free vision, this paper identifies marginal heat production costs and compares these to marginal heat savings costs for two different levels of district heating. A suitable least-cost heating strategy seems to be to invest in an approximately 50% decrease in net heat demands in new buildings and buildings that are being renovated anyway, while the implementation of heat savings in buildings that are not being renovated hardly pays. Moreover, the analysis points in the direction that a least-cost strategy will be to provide approximately 2/3 of the heat demand from district heating and the rest from individual heat pumps.

  18. In vitro induction of variability through radiation for late blight resistance and heat tolerance in potato

    International Nuclear Information System (INIS)

    Gosal, S.S.; Das, A.; Gopal, J.; Minocha, J.L.; Chopra, H.R.; Dhaliwal, H.S.

    2001-01-01

    In vitro cultured shoots of potato, cvs. 'Kufri Jyoti' and 'Kufri Chandramukhi', were irradiated with 20 and 40 Gy gamma rays. Microtubers, obtained from MIV3 shoots multiplied in vitro, were planted in pots. The resulting plants were screened for resistance to late blight, using detached leaf method. In 'Kufri Chandramukhi', 42% plants and in 'Kufri Jyoti' 36% plants, obtained from 40 Gy treatment, showed resistance to late blight. The frequency of resistant plants was lower from 20 Gy treatment. The progenies of putatively resistant plants were grown in field, and inoculated with sporangial inoculum of late blight fungus. The field grown progeny segregated for disease resistance, and approximately 56% plants showed resistance. During the next propagation, the frequency of resistant plants increased to 72%. For developing heat tolerance, microtubers obtained from 20 and 40 Gy treatments and in vitro multiplied M 1 V 3 shoots were cultured at high temperature of 28C. In both varieties, the number of the microtubers per plant was highly reduced and the resulting microtubers had distorted shape but showed better germination (62%), even in early sowing at relatively higher temperature. Of the two radiation doses, the higher dose of 40 Gy gave better results in both the varieties. Heat tolerance was also assessed from chlorophyll persistence. The progenies from putative heat-tolerant plants were tested in field by planting at higher temperature in two subsequent generations. The heat tolerant plants segregated in each generation, but the frequency of heat-tolerant plants increased. (author)

  19. Prototype solar heating and combined heating and cooling systems. Quarterly report No. 6

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-06

    The General Electric Company is developing eight prototype solar heating and combined heating and cooling systems. This effort includes development, manufacture, test, installation, maintenance, problem resolution, and performance evaluation.

  20. Low Temperature District Heating for Future Energy Systems

    DEFF Research Database (Denmark)

    Ford, Rufus; Pietruschka, Dirk; Sipilä, Kari

    This report titled “Case studies and demonstrations” is the subtask D report of the IEA DHC|CHP Annex TS1 project “Low Temperature District Heating for Future Energy Systems” carried out between 2013 and 2016. The project was led by Fraunhofer Institute for Building Physics (IBP) with the other...... include examples on low temperature district heating systems, solar heating in a district heating system, heat pump based heat supply and energy storages for both peak load management and for seasonal heat storage. Some demonstrations have been implemented while others are at planning phase...

  1. Application of Predictive Control in District Heating Systems

    DEFF Research Database (Denmark)

    Palsson, Olafur Petur; Madsen, Henrik; Søgaard, Henning Tangen

    1993-01-01

    In district heating systems, and in particular if the heat production cakes place at a combined heat and power (CHP) plant, a reasonable control strategy is to keep the supply temperature from the district heating plant as low as possible. However, the control is subject to some restrictions...

  2. 40 CFR 63.104 - Heat exchange system requirements.

    Science.gov (United States)

    2010-07-01

    ... heat exchange system or at locations where the cooling water enters and exits each heat exchanger or any combination of heat exchangers. (i) For samples taken at the entrance and exit of recirculating... manufacturing process units. (iii) For samples taken at the entrance and exit of each heat exchanger or any...

  3. Multiscale modeling of localized resistive heating in nanocrystalline metals subjected to electropulsing

    Science.gov (United States)

    Zhao, Jingyi; Wang, G.-X.; Dong, Yalin; Ye, Chang

    2017-08-01

    Many electrically assisted processes have been reported to induce changes in microstructure and metal plasticity. To understand the physics-based mechanisms behind these interesting phenomena, however, requires an understanding of the interaction between the electric current and heterogeneous microstructure. In this work, multiscale modeling of the electric current flow in a nanocrystalline material is reported. The cellular automata method was used to track the nanoscale grain boundaries in the matrix. Maxwell's electromagnetic equations were solved to obtain the electrical potential distribution at the macro scale. Kirchhoff's circuit equation was solved to obtain the electric current flow at the micro/nano scale. The electric current distribution at two representative locations was investigated. A significant electric current concentration was observed near the grain boundaries, particularly near the triple junctions. This higher localized electric current leads to localized resistive heating near the grain boundaries. The electric current distribution could be used to obtain critical information such as localized resistive heating rate and extra system free energy, which are critical for explaining many interesting phenomena, including microstructure evolution and plasticity enhancement in many electrically assisted processes.

  4. FFTF Heat Transport System (HTS) component and system design

    International Nuclear Information System (INIS)

    Young, M.W.; Edwards, P.A.

    1980-01-01

    The FFTF Heat Transport Systems and Components designs have been completed and successfully tested at isothermal conditions up to 427 0 C (800 0 F). General performance has been as predicted in the design analyses. Operational flexibility and reliability have been outstanding throughout the test program. The components and systems have been demonstrated ready to support reactor powered operation testing planned later in 1980

  5. Performance Analysis of a Hybrid District Heating System

    DEFF Research Database (Denmark)

    Mikulandric, Robert; Krajačić, Goran; Duic, Neven

    2015-01-01

    , the performance of a hybrid district energy system for a small town in Croatia has been analysed. Mathematical model for process analysis and optimisation algorithm for optimal system configuration has been developed and described. The main goal of the system optimisation is to reduce heat production costs....... Several energy sources for heat production have been considered in 8 different simulation cases. Simulation results show that the heat production costs could be reduced with introduction of different energy systems into an existing district heating system. Renewable energy based district heating systems...... could contribute to heat production costs decrease in district heating systems up to 30% in comparison with highly efficient heat production technologies based on conventional fuels....

  6. Limiting biomass consumption for heating in 100% renewable energy systems

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Lund, Henrik; Connolly, David

    2012-01-01

    -scale solar thermal, large heat pumps, geothermal heat, industrial surplus heat, and waste incineration. Where the energy density in the building stock is not high enough for DH to be economical, geothermal heat pumps can be recommended for individual heating systems, even though biomass consumption is higher......The utilisation of biomass poses large challenges in renewable energy systems while buildings account for a substantial part of the energy supply even in 100% renewable energy systems. In this paper the focus is on how the heating sector can reduce its consumption of biomass, thus leaving biomass...... for other sectors, but while still enabling a 100% renewable energy system. The analyses of heating technologies shows that district heating (DH) systems are important in limiting the dependence on biomass and create cost effective solutions. DH systems are especially important in renewable energy systems...

  7. Heat stress in chemical protective clothing: Porosity and vapour resistance

    NARCIS (Netherlands)

    Havenith, G.; Hartog, E.A. den; Martini, S.

    2011-01-01

    Heat strain in chemical protective clothing is an important factor in industrial and military practice. Various improvements to the clothing to alleviate strain while maintaining protection have been attempted. More recently, selectively permeable membranes have been introduced to improve

  8. 24 CFR 3285.905 - Heating oil systems.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Heating oil systems. 3285.905... Installation Instructions § 3285.905 Heating oil systems. It is recommended that the installation instructions include the following information related to heating oil systems, when applicable: (a) Homes equipped with...

  9. Targeting the maximum heat recovery for systems with heat losses and heat gains

    International Nuclear Information System (INIS)

    Wan Alwi, Sharifah Rafidah; Lee, Carmen Kar Mun; Lee, Kim Yau; Abd Manan, Zainuddin; Fraser, Duncan M.

    2014-01-01

    Graphical abstract: Illustration of heat gains and losses from process streams. - Highlights: • Maximising energy savings through heat losses or gains. • Identifying location where insulation can be avoided. • Heuristics to maximise heat losses or gains. • Targeting heat losses or gains using the extended STEP technique and HEAT diagram. - Abstract: Process Integration using the Pinch Analysis technique has been widely used as a tool for the optimal design of heat exchanger networks (HENs). The Composite Curves and the Stream Temperature versus Enthalpy Plot (STEP) are among the graphical tools used to target the maximum heat recovery for a HEN. However, these tools assume that heat losses and heat gains are negligible. This work presents an approach that considers heat losses and heat gains during the establishment of the minimum utility targets. The STEP method, which is plotted based on the individual, as opposed to the composite streams, has been extended to consider the effect of heat losses and heat gains during stream matching. Several rules to guide the proper location of pipe insulation, and the appropriate procedure for stream shifting have been introduced in order to minimise the heat losses and maximise the heat gains. Application of the method on two case studies shows that considering heat losses and heat gains yield more realistic utility targets and help reduce both the insulation capital cost and utility cost of a HEN

  10. Embedded resistance wire as a heating element for temperature control in microbioreactors

    DEFF Research Database (Denmark)

    Zainal Alam, Muhd Nazrul Hisham; Schäpper, Daniel; Gernaey, Krist

    2010-01-01

    This paper presents the technical realization of a low-cost heating element consisting of a resistance wire in a microbioreactor, as well as the implementation and performance assessment of an on/off controller for temperature control of the microbioreactor content based on this heating element...... surround the reactor chamber or are placed underneath it. The latter can achieve an even temperature distribution across the reactor chamber and direct heating of the reactor content. We show that an integrated resistance wire coupled to a simple on/off controller results in accurate temperature control...... temperature control in a batch Saccharomyces cerevisiae cultivation in a microbioreactor....

  11. Optimization of Solar Water Heating System under Time and Spatial Partition Heating in Rural Dwellings

    Directory of Open Access Journals (Sweden)

    Yanfeng Liu

    2017-10-01

    Full Text Available This paper proposes the application of time and spatial partition heating to a solar water heating system. The heating effect and system performance were analyzed under the continuous and whole space heating and time and spatial partition heating using TRNSYS. The results were validated by comparing with the test results of the demonstration building. Compared to continuous and whole space heating, the use of time and spatial partition heating increases the solar fraction by 16.5%, reduces the auxiliary heating by 7390 MJ, and reduces the annual operation cost by 2010 RMB. Under time and spatial partition heating, optimization analyses were conducted for the two system capacity parameters of the solar collector area and tank volume and the one operation parameter of auxiliary heater setting outlet temperature. The results showed that a reasonable choice of the solar collector area can reduce the dynamic annual cost, the increased tank volume is advantageous to heat storage, and the auxiliary heater setting outlet temperature have greater influence on the indoor heating effect. The advanced opening of solar water heating system and the normal opening of passive air vents are recommended. Based on the comparison of the two modes, the time and spatial partition heating technology is a better choice for rural dwellings.

  12. A simplified heat pump model for use in solar plus heat pump system simulation studies

    DEFF Research Database (Denmark)

    Perers, Bengt; Andersen, Elsa; Nordman, Roger

    2012-01-01

    Solar plus heat pump systems are often very complex in design, with sometimes special heat pump arrangements and control. Therefore detailed heat pump models can give very slow system simulations and still not so accurate results compared to real heat pump performance in a system. The idea here...... is to start from a standard measured performance map of test points for a heat pump according to EN 14825 and then determine characteristic parameters for a simplified correlation based model of the heat pump. By plotting heat pump test data in different ways including power input and output form and not only...... as COP, a simplified relation could be seen. By using the same methodology as in the EN 12975 QDT part in the collector test standard it could be shown that a very simple model could describe the heat pump test data very accurately, by identifying 4 parameters in the correlation equation found....

  13. A simplified heat pump model for use in solar plus heat pump system simulation studies

    DEFF Research Database (Denmark)

    Perers, Bengt; Andersen, Elsa; Nordman, Roger

    2012-01-01

    as COP, a simplified relation could be seen. By using the same methodology as in the EN 12975 QDT part in the collector test standard it could be shown that a very simple model could describe the heat pump test data very accurately, by identifying 4 parameters in the correlation equation found.......Solar plus heat pump systems are often very complex in design, with sometimes special heat pump arrangements and control. Therefore detailed heat pump models can give very slow system simulations and still not so accurate results compared to real heat pump performance in a system. The idea here...... is to start from a standard measured performance map of test points for a heat pump according to EN 14825 and then determine characteristic parameters for a simplified correlation based model of the heat pump. By plotting heat pump test data in different ways including power input and output form and not only...

  14. New Technology and Experimental Study on Snow-Melting Heated Pavement System in Tunnel Portal

    Directory of Open Access Journals (Sweden)

    Jinxing Lai

    2015-01-01

    Full Text Available In recent years, with the rapid growth of economy and sharp rise of motor vehicles in China, the pavement skid resistance in tunnel portals has become increasingly important in cold region. However, the deicing salt, snow removal with machine, and other antiskid measures adopted by highway maintenance division have many limitations. To improve the treatment effect, we proposed a new snow-melting approach employing electric heat tracing, in which heating cables are installed in the structural layer of road. Through the field experiment, laboratory experiment, and numerical investigation, structure type, heating power, and preheating time of the flexible pavement heating system in tunnel portal were systematically analyzed, and advantages of electric heat tracing technology in improving the pavement skid resistance in tunnel portal were also presented. Therefore, such new technology, which offers new snow-melting methods for tunnel portal, bridge, mountainous area, and large longitudinal slope in cold region, has promising prospect for extensive application.

  15. An Integrated Control System for Heating and Indoor Climate Applications

    DEFF Research Database (Denmark)

    Tahersima, Fatemeh

    2012-01-01

    which geothermal heat pump, solar driven heat pumps and the other types are categorized as renewable or renewable energy sources. In the present study, we investigated modeling and control of hydronic heat emitters integrated with a ground-source heat pump. Optimization of the system performance......Low temperature hydronic heating and cooling systems connected to renewable energy sources have gained more attention in the recent decades. This is due to the growing public awareness of the adverse environmental impacts of energy generation using fossil fuel. Radiant hydronic sub-floor heating...... pipes and radiator panels are two examples of such systems that have reputation of improving the quality of indoor thermal comfort compared to forced-air heating or cooling units. Specifically, a radiant water-based sub-floor heating system is usually combined with low temperature heat sources, among...

  16. Solar-powered turbocompressor heat pump system

    Science.gov (United States)

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

    1982-08-12

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

  17. Density Determination of Liquid Copper and Liquid Nickel by Means of Fast Resistive Pulse Heating and Electromagnetic Levitation

    Science.gov (United States)

    Schmon, Alexander; Aziz, Kirmanj; Pottlacher, Gernot

    2015-06-01

    Fast resistive pulse-heating techniques and electromagnetic levitation techniques are capable of determining thermophysical properties of metals in the liquid phase. These properties have become increasingly important as input data for modern numerical simulations. Among others, density is a very relevant parameter for e.g., casting modeling. Density determinations of copper and nickel in their liquid states are performed using a fast resistive pulse-heating setup and a recently build up electromagnetic levitation apparatus. Both methods use optical imaging techniques to determine thermal expansion of the specimen under investigation, but are operating at very different experimental durations. The pulse-heating setup provides a heating of the sample using it as part of an electrical discharge circuit. Heating rates of 108 K/s lead to experimental durations of about 60 µs. Temperature is determined by measuring surface radiance emitted from the sample by a pyrometer. The sample's thermal expansion is monitored by an adapted CCD camera system. The electromagnetic levitation apparatus enables noncontact investigations of samples by levitating and heating them by an induction coil generating inhomogeneous electromagnetic fields. Temperature again is determined by a pyrometer. For thermal expansion determination, shadowgraph images are recorded with a high-speed CCD camera and evaluated with an edge detection algorithm. Thermal expansion then is calculated by averaging several 1000 frames for each temperature point. Investigations of copper and nickel in the liquid state were performed with both techniques and are compared to each other and to literature values.

  18. Competitive solar heating systems for residential buildings

    DEFF Research Database (Denmark)

    Furbo, Simon; Thür, Alexander; Fiedler, Frank

    2005-01-01

    .D. studies in Denmark, Sweden and Latvia, and a post-doc. study in Norway. Close cooperation between the researchers and the industry partners ensures that the results of the project can be utilized. By the end of the project the industry partners will be able to bring the developed systems onto the market...... from an economical and architectural point of view. The project includes education, research, development and demonstration. The project started in 2003 and will be finished by the end of 2006. The participants of the project, which is financed by Nordic Energy Research and the participants themselves......The paper describes the ongoing research project “Competitive solar heating systems for residential buildings”. The aim of the project is to develop competitive solar combisystems which are attractive to buyers. The solar combisystems must be attractive compared to traditional energy systems, both...

  19. Understanding The Resistance to Health Information Systems

    Directory of Open Access Journals (Sweden)

    David Ackah

    2017-07-01

    Full Text Available User resistance is users’ opposition to system implementation. Resistance often occurs as a result of a mismatch between management goals and employee preferences. There are two types of resistance to health iformation system namely active resistance and passive resistance. The manifestation of active resistance are being critical,  blaming/accusing, blocking, fault finding, sabotaging, undermining, ridiculing, intimidating/threatening, starting rumors, appealing to fear, manipulating arguing, using facts selectively, distorting facts and  raising objections. The manifestation of passive resistance are agreeing verbally but not following through, failing to implement change, procrastinating/dragging feet, feigning ignorance, withholding information, suggestions, help or support, and standing by and allowing the change to fail.

  20. Functional Analysis of Genes Comprising the Locus of Heat Resistance in Escherichia coli.

    Science.gov (United States)

    Mercer, Ryan; Nguyen, Oanh; Ou, Qixing; McMullen, Lynn; Gänzle, Michael G

    2017-10-15

    The locus of heat resistance (LHR) is a 15- to 19-kb genomic island conferring exceptional heat resistance to organisms in the family Enterobacteriaceae , including pathogenic strains of Salmonella enterica and Escherichia coli The complement of LHR-comprising genes that is necessary for heat resistance and the stress-induced or growth-phase-induced expression of LHR-comprising genes are unknown. This study determined the contribution of the seven LHR-comprising genes yfdX1 GI , yfdX2 , hdeD GI , orf11 , trx GI , kefB , and psiE GI by comparing the heat resistances of E. coli strains harboring plasmid-encoded derivatives of the different LHRs in these genes. (Genes carry a subscript "GI" [genomic island] if an ortholog of the same gene is present in genomes of E. coli ) LHR-encoded heat shock proteins sHSP20, ClpK GI , and sHSP GI are not sufficient for the heat resistance phenotype; YfdX1, YfdX2, and HdeD are necessary to complement the LHR heat shock proteins and to impart a high level of resistance. Deletion of trx GI , kefB , and psiE GI from plasmid-encoded copies of the LHR did not significantly affect heat resistance. The effect of the growth phase and the NaCl concentration on expression from the putative LHR promoter p2 was determined by quantitative reverse transcription-PCR and by a plasmid-encoded p2:GFP promoter fusion. The expression levels of exponential- and stationary-phase E. coli cells were not significantly different, but the addition of 1% NaCl significantly increased LHR expression. Remarkably, LHR expression in E. coli was dependent on a chromosomal copy of evgA In conclusion, this study improved our understanding of the genes required for exceptional heat resistance in E. coli and factors that increase their expression in food. IMPORTANCE The locus of heat resistance (LHR) is a genomic island conferring exceptional heat resistance to several foodborne pathogens. The exceptional level of heat resistance provided by the LHR questions the

  1. Experimental investigation on an integrated thermal management system with heat pipe heat exchanger for electric vehicle

    International Nuclear Information System (INIS)

    Zou, Huiming; Wang, Wei; Zhang, Guiying; Qin, Fei; Tian, Changqing; Yan, Yuying

    2016-01-01

    Highlights: • An integrated thermal management system is proposed for electric vehicle. • The parallel branch of battery chiller can supply additional cooling capacity. • Heat pipe performance on preheating mode is better than that on cooling mode. • Heat pipe heat exchanger is a feasible choice for battery thermal management. - Abstract: An integrated thermal management system combining a heat pipe battery cooling/preheating system with the heat pump air conditioning system is presented to fulfill the comprehensive energy utilization for electric vehicles. A test bench with battery heat pipe heat exchanger and heat pump air conditioning for a regular five-chair electric car is set up to research the performance of this integrated system under different working conditions. The investigation results show that as the system is designed to meet the basic cabinet cooling demand, the additional parallel branch of battery chiller is a good way to solve the battery group cooling problem, which can supply about 20% additional cooling capacity without input power increase. Its coefficient of performance for cabinet heating is around 1.34 at −20 °C out-car temperature and 20 °C in-car temperature. The specific heat of the battery group is tested about 1.24 kJ/kg °C. There exists a necessary temperature condition for the heat pipe heat exchanger to start action. The heat pipe heat transfer performance is around 0.87 W/°C on cooling mode and 1.11 W/°C on preheating mode. The gravity role makes the heat transfer performance of the heat pipe on preheating mode better than that on cooling mode.

  2. Compact interior heat exchangers for CO{sub 2} mobile heat pumping systems

    Energy Technology Data Exchange (ETDEWEB)

    Hafner, Armin

    2003-07-01

    The natural refrigerant carbon dioxide (CO{sub 2}) offers new possibilities for design of flexible, efficient and environmentally safe mobile heat pumping systems. As high-efficient car engines with less waste heat are developed, extra heating of the passenger compartment is needed in the cold season. A reversible transcritical CO{sub 2} system with gliding temperature heat rejection can give high air delivery temperature which results in rapid heating of the passenger compartment and rapid defogging or defrosting of windows. When operated in cooling mode, the efficiency of transcritical CO{sub 2} systems is higher compared to common (HFC) air conditioning systems, at most dominant operating conditions. Several issues were identified for the design of compact interior heat exchangers for automotive reversible CO{sub 2} heat pumping systems. Among theses issues are: (1) Refrigerant flow distribution, (2) Heat exchanger fluid flow circuiting, (3) Air temperature uniformity downstream of the heat exchanger, (4) Minimization of temperature approach, (5) Windshield flash fogging due to retained water inside the heat exchanger, (6) Internal beat conduction in heating mode operation, and (7) Refrigerant side pressure drop In order to provide a basis for understanding these issues, the author developed a calculation model and set up a test facility and investigated different prototype heat exchangers experimentally.

  3. Investigation of a heat storage for a solar heating system for combined space heating and domestic hot water supply for homeowner´s association "Bakken"

    DEFF Research Database (Denmark)

    Vejen, Niels Kristian

    1998-01-01

    A heat storage for a solar heating system for combined space heating and domestic hot water supply was tested in a laboratory test facility.The heat storage consist of a mantle tank with water for the heating system and of a hot water tank, which by means of thermosyphoning is heated by the water...... in the heating system. The heat storage was tested in a heat storage test facility. The most important characteristics of the heat storage were determined by means of the tests and recommendations for the design of the heat storage were given....

  4. Heat Saving Strategies in Sustainable Smart Energy Systems

    DEFF Research Database (Denmark)

    Lund, Henrik; Thellufsen, Jakob Zinck; Aggerholm, Søren

    One of the important issues related to the implementation of future sustainable smart energy systems based on renewable energy sources is the heating of buildings. Especially, when it comes to long‐term investment in savings and heating infrastructures it is essential to identify long‐term least......‐cost strategies. With Denmark as a case, this paper investigates to which extent heat should be saved rather than produced and to which extent district heating infrastructures, rather than individual heating solutions, should be used. Based on a concrete proposal to implement the Danish governmental long...... that a least‐cost strategy will be to provide approximately 2/3 of the heat demand from district heating and the rest from individual heat pumps. Keywords: Energy Efficiency, Renewable energy, Heating strategy, Heat savings, District heating, Smart energy...

  5. Improved dental implant drill durability and performance using heat and wear resistant protective coatings.

    Science.gov (United States)

    Er, Nilay; Alkan, Alper; İlday, Serim; Bengu, Erman

    2018-03-02

    Dental implant drilling procedure is an essential step for implant surgery and frictional heat appeared in bone during drilling is a key factor affecting the success of an implant. The aim of this study is to increase the dental implant drill lifetime and performance using heat- and wear-resistant protective coatings hence to decrease the alveolar bone temperature caused by the dental implant drilling procedure. Commercially obtained stainless steel drills were coated with titanium aluminum nitride, diamond-like carbon, titanium boron nitride, and boron nitride coatings via magnetron-sputter deposition. Drilling procedure was performed on a bovine femoral cortical bone under the conditions mimicking clinical practice, where the tests were performed both under water-assisted cooling and under the conditions without any cooling was applied. Coated drill performances and durabilities were compared to that of three commonly used commercial drills which surfaces are made from namely; zirconia, black diamond and stainless steel. Protective coatings with boron nitride, titanium boron nitride and diamond-like carbon have significantly improved drill performance and durability. Especially boron nitride-coated drills have performed within safe bone temperature limits for 50 drillings even without any cooling is applied. Titanium aluminium nitride coated drills did not show any improvement over commercially obtained stainless steel drills. Surface modification using heat and wear resistant coatings is an easy and highly effective way to improve implant drill performance and durability, which can reflect positively on surgical procedure and healing period afterwards. The noteworthy success of different types of coatings is novel and likely to be applicable to various other medical systems.

  6. Comparative proteomic and metabolomic profiling of citrus fruit with enhancement of disease resistance by postharvest heat treatment.

    Science.gov (United States)

    Yun, Ze; Gao, Huijun; Liu, Ping; Liu, Shuzhen; Luo, Tao; Jin, Shuai; Xu, Qiang; Xu, Juan; Cheng, Yunjiang; Deng, Xiuxin

    2013-03-16

    From field harvest to the consumer's table, fresh citrus fruit spends a considerable amount of time in shipment and storage. During these processes, physiological disorders and pathological diseases are the main causes of fruit loss. Heat treatment (HT) has been widely used to maintain fruit quality during postharvest storage; however, limited molecular information related to this treatment is currently available at a systemic biological level. Mature 'Kamei' Satsuma mandarin (Citrus unshiu Marc.) fruits were selected for exploring the disease resistance mechanisms induced by HT during postharvest storage. Proteomic analyses based on two-dimensional gel electrophoresis (2-DE), and metabolomic research based on gas chromatography coupled to mass spectrometry (GC-MS), and liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QToF-MS) were conducted. The results show resistance associated proteins were up-regulated in heat treated pericarp, such as beta-1, 3-glucanase, Class III chitinase, 17.7 kDa heat shock protein and low molecular weight heat-shock protein. Also, redox metabolism enzymes were down-regulated in heat treated pericarp, including isoflavone reductase, oxidoreductase and superoxide dismutase. Primary metabolic profiling revealed organic acids and amino acids were down-regulated in heat treated pericarp; but significant accumulation of metabolites, including tetradecanoic acid, oleic acid, ornithine, 2-keto-d-gluconic acid, succinic acid, turanose, sucrose, galactose, myo-inositol, glucose and fructose were detected. Noticeably, H2O2 content decreased, while, lignin content increased in heat treated pericarp compared to the control, which might increase fruit resistibility in response to external stress. Also, flavonoids, substances which are well-known to be effective in reducing external stress, were up-regulated in heat treated pericarp. This study provides a broad picture of differential accumulation of proteins and metabolites in

  7. Influence of Heat Treatment on Mercury Cavitation Resistance of Surface Hardened 316LN Stainless Steel

    Energy Technology Data Exchange (ETDEWEB)

    Pawel, Steven J [ORNL; Hsu, Julia [Massachusetts Institute of Technology (MIT)

    2010-11-01

    The cavitation-erosion resistance of carburized 316LN stainless steel was significantly degraded but not destroyed by heat treatment in the temperature range 500-800 C. The heat treatments caused rejection of some carbon from the carburized layer into an amorphous film that formed on each specimen surface. Further, the heat treatments encouraged carbide precipitation and reduced hardness within the carburized layer, but the overall change did not reduce surface hardness fully to the level of untreated material. Heat treatments as short as 10 min at 650 C substantially reduced cavitation-erosion resistance in mercury, while heat treatments at 500 and 800 C were found to be somewhat less detrimental. Overall, the results suggest that modest thermal excursions perhaps the result of a weld made at some distance to the carburized material or a brief stress relief treatment will not render the hardened layer completely ineffective but should be avoided to the greatest extent possible.

  8. Development of an air heating system for single family housing

    DEFF Research Database (Denmark)

    Afshari, Alireza; Gunner, Amalie; Nikolaisen, Christian Grønborg

    2017-01-01

    The initial objective of the project was to break with common thinking about Space heating and to document that air heating can be used as the sole source of heating in a single Family house. The basic idea is that the ventilation must be installed in any case and it may equally well form the heat...... source of the house - Thus the waterborne heating system can be eliminated....

  9. The realization of temperature controller for small resistance measurement system

    Science.gov (United States)

    Sobecki, Jakub; Walendziuk, Wojciech; Idzkowski, Adam

    2017-08-01

    This paper concerns the issues of construction and experimental tests of a temperature stabilization system for small resistance increments measurement circuits. After switching the system on, a PCB board heats up and the long-term temperature drift altered the measurement result. The aim of this work is reducing the time of achieving constant nominal temperature by the measurement system, which would enable decreasing the time of measurements in the steady state. Moreover, the influence of temperatures higher than the nominal on the measurement results and the obtained heating curve were tested. During the working process, the circuit heats up to about 32 °C spontaneously, and it has the time to reach steady state of about 1200 s. Implementing a USART terminal on the PC and an NI USB-6341 data acquisition card makes recording the data (concerning temperature and resistance) in the digital form and its further processing easier. It also enables changing the quantity of the regulator settings. This paper presents sample results of measurements for several temperature values and the characteristics of the temperature and resistance changes in time as well as their comparison with the output values. The object identification is accomplished due to the Ziegler-Nichols method. The algorithm of determining the step characteristics parameters and examples of computations of the regulator settings are included together with example characteristics of the object regulation.

  10. Simulation and energy analysis of distributed electric heating system

    Science.gov (United States)

    Yu, Bo; Han, Shenchao; Yang, Yanchun; Liu, Mingyuan

    2018-02-01

    Distributed electric heating system assistssolar heating systemby using air-source heat pump. Air-source heat pump as auxiliary heat sourcecan make up the defects of the conventional solar thermal system can provide a 24 - hour high - efficiency work. It has certain practical value and practical significance to reduce emissions and promote building energy efficiency. Using Polysun software the system is simulated and compared with ordinary electric boiler heating system. The simulation results show that upon energy request, 5844.5kW energy is saved and 3135kg carbon - dioxide emissions are reduced and5844.5 kWhfuel and energy consumption is decreased with distributed electric heating system. Theeffect of conserving energy and reducing emissions using distributed electric heating systemis very obvious.

  11. Extreme Heat Resistance of Food Borne Pathogens Campylobacter jejuni, Escherichia coli, and Salmonella typhimurium on Chicken Breast Fillet during Cooking

    DEFF Research Database (Denmark)

    de Jong, Aarieke E I; van Asselt, Esther D; Zwietering, Marcel H

    2012-01-01

    cooking enlarged the heat resistance of the food borne pathogens. Additionally, a high challenge temperature or fast heating rate contributed to the level of heat resistance. The data were used to assess the probability of illness (campylobacteriosis) due to consumption of chicken fillet as a function...

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

    International Nuclear Information System (INIS)

    1981-01-01

    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. 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...

  14. Intermediate temperature, heat storage and retrieval system

    Energy Technology Data Exchange (ETDEWEB)

    Greene, N.D.

    1980-10-14

    Energy is stored by heating a salt to a temperature above its latent heat of fusion to convert the salt to a liquid state. Heat is retrieved by moving a heat transfer fluid that is immiscible with the salt and has a density less than that of the salt over the top surface of the liquid salt at such a velocity that the upper layer of the salt is emulsified with the heat transfer fluid to crystallize the salt in the upper layer. Heat is thereby exothermally surrendered to the heat transfer fluid and the crystallized salt gravitates from said top surface, thereby maintaining the top surface in a liquid state. It is preferred to move the heat transfer fluid over the top surface of the salt in either a vortex pattern, or an outward radial pattern. The heat transfer liquid is a liquid selected from the group consisting essentially of therminol, caloria santowax, and di-butyl phthalate.

  15. 14 CFR 25.833 - Combustion heating systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Combustion heating systems. 25.833 Section... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Ventilation and Heating § 25.833 Combustion heating systems. Combustion heaters must be approved. [Amdt. 25-72, 55 FR 29783, July 20, 1990...

  16. Inductively heated particulate matter filter regeneration control system

    Science.gov (United States)

    Gonze, Eugene V; Paratore Jr., Michael J; Kirby, Kevin W; Phelps, Amanda; Gregoire, Daniel J

    2012-10-23

    A system includes a particulate matter (PM) filter with an upstream end for receiving exhaust gas, a downstream end and zones. The system also includes a heating element. A control module selectively activates the heating element to inductively heat one of the zones.

  17. Thermal Propulsion Capture System Heat Exchanger Design

    Science.gov (United States)

    Richard, Evan M.

    2016-01-01

    One of the biggest challenges of manned spaceflight beyond low earth orbit and the moon is harmful radiation that astronauts would be exposed to on their long journey to Mars and further destinations. Using nuclear energy has the potential to be a more effective means of propulsion compared to traditional chemical engines (higher specific impulse). An upper stage nuclear engine would allow astronauts to reach their destination faster and more fuel efficiently. Testing these engines poses engineering challenges due to the need to totally capture the engine exhaust. The Thermal Propulsion Capture System is a concept for cost effectively and safely testing Nuclear Thermal Engines. Nominally, hydrogen exhausted from the engine is not radioactive, but is treated as such in case of fuel element failure. The Thermal Propulsion Capture System involves injecting liquid oxygen to convert the hydrogen exhaust into steam. The steam is then cooled and condensed into liquid water to allow for storage. The Thermal Propulsion Capture System concept for ground testing of a nuclear powered engine involves capturing the engine exhaust to be cooled and condensed before being stored. The hydrogen exhaust is injected with liquid oxygen and burned to form steam. That steam must be cooled to saturation temperatures before being condensed into liquid water. A crossflow heat exchanger using water as a working fluid will be designed to accomplish this goal. Design a cross flow heat exchanger for the Thermal Propulsion Capture System testing which: Eliminates the need for water injection cooling, Cools steam from 5800 F to saturation temperature, and Is efficient and minimizes water requirement.

  18. Mechanisms underlying extreme heat resistance of ascospores of Neosartorya fischeri

    NARCIS (Netherlands)

    Wyatt, T.T.

    2014-01-01

    Food spoilage causes immense losses of food products worldwide and negatively affects human health due the production of toxic compounds, so-called mycotoxins. Worldwide economic costs related to fungal spoilage amounts billions of euro each year. Mild heat treatments are used to minimize fungal

  19. (ajst) effect of heat treatment on wear resistance

    African Journals Online (AJOL)

    of the specimens examined under an optical microscope. The hardness values of the grinding plate specimens quenched in various media increased with increased heat treatment temperatures, and are higher than that of the as-cast specimen. Water quenched tempered specimens (WT) displayed higher hardness values ...

  20. Heat exchanger bypass system for an absorption refrigeration system

    Science.gov (United States)

    Reimann, Robert C.

    1984-01-01

    A heat exchanger bypass system for an absorption refrigeration system is disclosed. The bypass system operates to pass strong solution from the generator around the heat exchanger to the absorber of the absorption refrigeration system when strong solution builds up in the generator above a selected level indicative of solidification of strong solution in the heat exchanger or other such blockage. The bypass system includes a bypass line with a gooseneck located in the generator for controlling flow of strong solution into the bypass line and for preventing refrigerant vapor in the generator from entering the bypass line during normal operation of the refrigeration system. Also, the bypass line includes a trap section filled with liquid for providing a barrier to maintain the normal pressure difference between the generator and the absorber even when the gooseneck of the bypass line is exposed to refrigerant vapor in the generator. Strong solution, which may accumulate in the trap section of the bypass line, is diluted, to prevent solidification, by supplying weak solution to the trap section from a purge system for the absorption refrigeration system.

  1. The heat shock protein/chaperone network and multiple stress resistance

    KAUST Repository

    Jacob, Pierre

    2016-11-15

    Crop yield has been greatly enhanced during the last century. However, most elite cultivars are adapted to temperate climates and are not well suited to more stressful conditions. In the context of climate change, stress resistance is a major concern. To overcome these difficulties, scientists may help breeders by providing genetic markers associated with stress resistance. However, multi-stress resistance cannot be obtained from the simple addition of single stress resistance traits. In the field, stresses are unpredictable and several may occur at once. Consequently, the use of single stress resistance traits is often inadequate. Although it has been historically linked with the heat stress response, the heat shock protein (HSP)/chaperone network is a major component of multiple stress responses. Among the HSP/chaperone

  2. Investigation of passive residual heat removal system for VVERs: Effects of finned type heat exchanger tubes

    International Nuclear Information System (INIS)

    Ayhan, Hüseyin; Sökmen, Cemal Niyazi

    2016-01-01

    Highlights: • Performance of passive residual heat removal system (PRHRS) of VVER type nuclear power plants is investigated. • Unit heat exchanger of PRHRS is designed to reject 4 MW heat amount from reactor via steam generator. • This study shows that decay heat can be rejected by 16 heat exchangers of PRHRS without any operator actions. - Abstract: After nuclear reactor shutdown, decay heat generation continues in the reactor core and it has the possibility to cause a severe accident. This residual heat has to be removed from the core sufficiently. In Water-Water Energetic Reactors (WWER) or VVERs, passive residual heat removal system is designed to remove decay heat after reactor shutdown. This system does not need any power operation, since ambient air is used as the cooling fluid in heat exchanger. The steam that is generated in the steam generators due to the heat released in the reactor core condenses and rejects its heat to the ambient air within this heat exchanger. The condensed liquid is returned back to the steam generator. The motion of the cooling medium occurs due to natural circulation. In the presented study, the original geometric design of passive residual heat removal system of VVER type nuclear power plants is introduced. The performance of this system is investigated. In the previous study, geometric design parameters for this system was determined for plain tubes of heat exchanger. Heat exchanger tubes were positioned as a helical in the previous study. With the knowledge of enhancing heat transfer using finned surfaces, geometrical design is modified in presented study. Circular type fin structures (having rectangular cross-section) are added to the outer surface of heat exchanger tubes. In the present heat exchanger model, tubes are positioned as a staggered bank. As the fin parameters, fin thickness, fin radius and total fin number are investigated in this study. Results are compared with the one obtained with plane tube (in tube

  3. Electrical energy use in different heating systems for early weaned piglets

    Energy Technology Data Exchange (ETDEWEB)

    Sarubbi, J. [Federal Univ. of Santa Maria, Palmeira das Missoes, RS (Brazil). Dept. of Animal Science; Campinas State Univ., Sao Paulo (Brazil). College of Agricultural Engineering; Rossi, L.A.; Moura, D.J.; Oliveira, R.A.; David, E. [Campinas State Univ., Sao Paulo (Brazil). College of Agricultural Engineering

    2010-07-01

    This study compared the electrical energy use and thermal comfort conditions associated with 3 heating technologies used in piglet farms. Heating systems for piglets in nursery and farrowing can be improved to conserve energy without affecting the welfare of the animals. The evaluation was conducted at a commercial farm in a subtropical climate area of Brazil. Each treatment involved 150 weaned piglets at 21 days-old. The systems were designed to keep the piglets at 28 to 30 degrees C for 14 days. Suspended electrical resistors, heated floors and convection heating were the 3 heating technologies examined during this study which evaluated the electrical energy consumption, maximum power demand requirements and dry-bulb temperature. The study also assessed the specific consumption in terms of kWh/kg of live produced body mass as well as the efficiency of heating system in terms of degrees C per cubic metre of air. In terms of electrical energy use, the best heating system was the heated floor. However, the electrical resistance heating system was the best in terms of thermal comfort.

  4. 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.

  5. New latent heat storage system with nanoparticles for thermal management of electric vehicles

    Science.gov (United States)

    Javani, N.; Dincer, I.; Naterer, G. F.

    2014-12-01

    In this paper, a new passive thermal management system for electric vehicles is developed. A latent heat thermal energy storage with nanoparticles is designed and optimized. A genetic algorithm method is employed to minimize the length of the heat exchanger tubes. The results show that even the optimum length of a shell and tube heat exchanger becomes too large to be employed in a vehicle. This is mainly due to the very low thermal conductivity of phase change material (PCM) which fills the shell side of the heat exchanger. A carbon nanotube (CNT) and PCM mixture is then studied where the probability of nanotubes in a series configuration is defined as a deterministic design parameter. Various heat transfer rates, ranging from 300 W to 600 W, are utilized to optimize battery cooling options in the heat exchanger. The optimization results show that smaller tube diameters minimize the heat exchanger length. Furthermore, finned tubes lead to a higher heat exchanger length due to more heat transfer resistance. By increasing the CNT concentration, the optimum length of the heat exchanger decreases and makes the improved thermal management system a more efficient and competitive with air and liquid thermal management systems.

  6. Improving Heat Pump Water Heater Effeciency by Avoiding Electric Resistance Heater Use

    Energy Technology Data Exchange (ETDEWEB)

    Boudreaux, Philip R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Munk, Jeffrey D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jackson, Roderick K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gehl, Anthony C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Parkison, April E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Nutaro, James J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-09-01

    Heat pump water heaters (HPWHs) are a promising technology that can decrease the domestic hot water energy consumption over an electric resistance storage water heater by up to 50%. Heat pump water heaters are really two water heaters in one; they can heat water by using a heat pump or by using electric resistance elements. During large water draw events the HPWHs will use the resistance elements that decrease the overall efficiency of the units. ORNL proposed and tested an advanced control algorithm that anticipates the large water draw events and appropriately sets-up the temperature of the tank water using only the heat pump. With sufficient energy stored in the tank at the elevated temperature, the large water draw is provided for and electric resistance use is avoided. Simulations using a validated heat pump water heater model, and measured water draw data from 25 homes, show average yearly energy savings of 9% for the advanced control algorithm. If the advanced control algorithm perfectly predicts the large water draw events then the savings increase to 19%. This discrepancy could be due to a lack of predictability of water draw patterns in some homes, or the water draw forecasting algorithm could be improved.

  7. Heat resistance of Bacillus cereus spores: effects of milk constituents and stabilizing additives.

    Science.gov (United States)

    Mazas, M; López, M; Martínez, S; Bernardo, A; Martin, R

    1999-04-01

    Heat resistance of Bacillus cereus spores (ATCC 7004, 4342, and 9818) heated in different types of milk (skim, whole, and concentrated skim milk), skim milk containing stabilizing additives (sodium citrate, monopotassium phosphate, or disodium phosphate, 0.1%), and cream was investigated. Thermal resistance experiments were performed at temperatures within the range of 92 to 115 degrees C under continuous monitoring of pH. For strain 4342 no significant differences (P < 0.05) in D values were detected in any case. For strains 7004 and 9818 higher D values of about 20% were obtained in whole and concentrated skim milk than those calculated in skim milk. From all stabilizing additives tested, only sodium citrate and sodium phosphate increased the heat resistance for strain 9818. However, when the menstruum pH was measured at the treatment temperature, different pH values were found between the heating media. The differences in heat resistance observed could be due to a pH effect rather than to the difference in the substrates in which spores were heated. In contrast, when cream (fat content 20%) was used, lower D values were obtained, especially for strains 7004 and 9818. z values were not significantly modified by the milk composition, with an average z value of 7.95+/-0.20 degrees C for strain 7004, 7.88+/-0.10 degrees C for strain 4342, and 9.13+/-0.16 degrees C for strain 9818.

  8. Frictional and heat resistance characteristics of coconut husk particle filled automotive brake pad

    Science.gov (United States)

    Bahari, Shahril Anuar; Chik, Mohd Syahrizul; Kassim, Masitah Abu; Som Said, Che Mohamad; Misnon, Mohd Iqbal; Mohamed, Zulkifli; Othman, Eliasidi Abu

    2012-06-01

    The objective of this study was to determine the friction and heat resistance characteristics of automotive brake pad composed with different sizes and percentages of coconut husk particle. The materials used were phenolic resin (phenol formaldehyde) as binder, copper, graphite and brass as friction producer/modifiers, magnesium oxide as abrasive material, steel and barium sulfate as reinforcement while coconut husk particle as filler. To obtain particle, the coconut husk was ground and dried to 3% moisture content. Then the coconut husk particle was screened using 80 mesh (to obtain coarse dust) and 100 mesh (to obtain fine dust). Different percentages of particle, such as 10 and 30% were used in the mixture of brake pad materials. Then the mixture was hot-pressed to produce brake pad. Chase machine was used to determine the friction coefficient in friction resistance testing, while thermogravimetric analyzer (TGA) machine was used to determine the heat decomposition values in heat resistance testing. Results showed that brake pad with 100 mesh and 10% composition of coconut husk particle showed the highest friction coefficient. For heat resistance, brake pad with 100 mesh and 30% composition of coconut husk dust showed the highest decomposition temperature, due to the high percentage of coconut husk particle in the composition, thus increased the thermal stability. As a comparison, brake pad composed with coconut husk particle showed better heat resistance results than commercial brake pad.

  9. Experimental study of a photovoltaic solar-assisted heat-pump/heat-pipe system

    International Nuclear Information System (INIS)

    Fu, H.D.; Pei, G.; Ji, J.; Long, H.; Zhang, T.; Chow, T.T.

    2012-01-01

    A practical design for a heat pump with heat-pipe photovoltaic/thermal (PV/T) collectors is presented. The hybrid system is called the photovoltaic solar-assisted heat-pump/heat-pipe (PV-SAHP/HP) system. To focus on both actual demand and energy savings, the PV-SAHP/HP system was designed to be capable of operating in three different modes, namely, the heat-pipe, solar-assisted heat pump, and air-source heat-pump modes. Based on solar radiation, the system operates in an optimal mode. A series of experiments were conducted in Hong Kong to study the performance of the system when operating in the heat-pipe and the solar-assisted heat-pump modes. Moreover, energy and exergy analyses were used to investigate the total PV/T performance of the system. - Highlights: ► A novel PV-SAHP/HP system with three different operating modes was proposed. ► Performance of the PV-SAHP/HP system was studied experimentally. ► A optimal operating mode of the PV-SAHP/HP system was suggested in this paper.

  10. Comparison of resistive heating and forced-air warming to prevent inadvertent perioperative hypothermia.

    Science.gov (United States)

    John, M; Crook, D; Dasari, K; Eljelani, F; El-Haboby, A; Harper, C M

    2016-02-01

    Forced-air warming is a commonly used warming modality, which has been shown to reduce the incidence of inadvertent perioperative hypothermia (heating mattresses offer a potentially cheaper alternative, however, and one of the research recommendations from the National Institute for Health and Care Excellence was to evaluate such devices formally. We conducted a randomized single-blinded study comparing perioperative hypothermia in patients receiving resistive heating or forced-air warming. A total of 160 patients undergoing non-emergency surgery were recruited and randomly allocated to receive either forced-air warming (n=78) or resistive heating (n=82) in the perioperative period. Patient core temperatures were monitored after induction of anaesthesia until the end of surgery and in the recovery room. Our primary outcome measures included the final intraoperative temperature and incidence of hypothermia at the end of surgery. There was a significantly higher rate of hypothermia at the end of surgery in the resistive heating group compared with the forced-air warming group (P=0.017). Final intraoperative temperatures were also significantly lower in the resistive heating group (35.9 compared with 36.1°C, P=0.029). Hypothermia at the end of surgery in both warming groups was common (36% forced air warming, 54% resistive heating). Our results suggest that forced-air warming is more effective than resistive heating in preventing postoperative hypothermia. NCT01056991. © The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Numerical Investigation of Floor Heating Systems in Low Energy Houses

    DEFF Research Database (Denmark)

    Weitzmann, Peter; Kragh, Jesper; Jensen, Claus Franceos

    2002-01-01

    In this paper an investigation of floor heating systems is performed with respect to heating demand and room temperature. Presently (2001) no commercially available building simulation programs that can be used to evaluate heating demand and thermal comfort in buildings with building integrated....... The model calculates heating demand, room temperatures, and thermal comfort parameters for a person in the room. The model is based on a numerical Finite Control Volume (FCV) method for the heat transfer in walls, ceiling, windows and floor. The model uses both convective and radiative heat transfer...... to the room air and between the room surfaces. The simulation model has been used to calculate heating demand and room temperature in a typical well insulated Danish single-family house with a heating demand of approximately 6000 kWh per year, for a 130 m² house. Two different types of floor heating systems...

  12. Solar/electric heating systems for the future energy system

    DEFF Research Database (Denmark)

    Furbo, Simon; Dannemand, Mark; Perers, Bengt

    partners in two connected projects in order to develop solar/electric heating systems for laboratory tests. The project was financed by the Danish Agency for Science, Technology and Innovation under the Danish Council for Strategic Research in the program Sustainable Energy and Environment. The DSF number......The project “Solar/electric heating systems in the future energy system” was carried out in the period 2008‐2013. The project partners were DTU Byg, DTU Informatics (now DTU Compute), DMI, ENFOR A/S and COWI A/S. The companies Ajva ApS, Ohmatex ApS and Innogie ApS worked together with the project...... of the project is 2104‐07‐0021/09‐063201/DSF. This report is the final report of the project. The aim of the project is to elucidate how individual heating units for single family houses are best designed in order to fit into the future energy system. The units are based on solar energy, electrical heating...

  13. Residential space heating systems: energy conservation and economics

    Energy Technology Data Exchange (ETDEWEB)

    O' Neal, D.L.

    1979-01-01

    Annual energy use for residential space heating was 8.6 Quads in 1975. This accounted for over 50% of the energy used in the residential sector and 12% of energy used in the U.S. that year. Because residential space heating accounts for such a large share of energy use, improvements in new space heating systems could have significant long-term conservation effects. Several energy-saving design changes in residential space heating systems are examined to determine their energy conservation potential and cost effectiveness. Both changes in conventional and advanced systems are considered. Conventional design changes include options such as the flue damper, sealed combustion, electric ignition and improved heat exchangers. Some of the advanced designs include the gas heat pump, pulse combustion furnace, and dual speed compressor heat pump. The energy use and cost estimates are developed from current literature, heating and equipment manufacturers and dealers, and discussions with individuals doing research and testing on residential space heating equipment. Results indicate that implementation of conventional design changes can reduce energy use of representative gas, oil, and electric space heating systems by 26, 20, and 57%, respectively. These changes increase the capital cost of the systems by 27, 16, and 26%. Advanced gas and electric space heating systems can reduce energy use 45 and 67%, respectively. However, the advanced systems cost 80 and 35% more than representative gas and electric systems.

  14. Impact of Seasonal Heat Accumulation on Operation of Geothermal Heat Pump System with Vertical Ground Heat Exchanger

    Science.gov (United States)

    Timofeev, D. V.; Malyavina, E. G.

    2017-11-01

    The subject of the investigation was to find out the influence of heat pump operation in summer on its function in winter. For this purpose a mathematical model of a ground coupled heat pump system has been developed and programmed. The mathematical model of a system ground heat exchanger uses the finite difference method to describe the heat transfer in soil and the analytical method to specify the heat transfer in the U-tubes heat exchanger. The thermal diffusivity by the heat transfer in the soil changes during gradual freezing of the pore moisture and thus slows soil freezing. The mathematical model of a heat pump includes the description of a scroll compressor and the simplified descriptions of the evaporator and condenser. The analysis showed that heating during the cold season and cooling in the warm season affect the average heat transfer medium temperature in the soil loop in the winter season. It has been also showed that the degree of this effect depends on the clay content in the soil.

  15. Residential heat pumps in the future Danish energy system

    DEFF Research Database (Denmark)

    Petrovic, Stefan; Karlsson, Kenneth Bernard

    2016-01-01

    Denmark is striving towards 100% renewable energy system in 2050. Residential heat pumps are expected to be a part of that system.We propose two novel approaches to improve the representation of residential heat pumps: Coefficients of performance (COPs) are modelled as dependent on air and ground...... temperature while installation of ground-source heat pumps is constrained by available ground area. In this study, TIMES-DK model is utilised to test the effects of improved modelling of residential heat pumps on the Danish energy system until 2050.The analysis of the Danish energy system was done...... for politically agreed targets which include: at least 50% of electricity consumption from wind power starting from 2020, fossil fuel free heat and power sector from 2035 and 100% renewable energy system starting from 2050. Residential heat pumps supply around 25% of total residential heating demand after 2035...

  16. HEAT TRANSFER AND TRITIUM PRODUCING SYSTEM

    Science.gov (United States)

    Johnson, E.F.

    1962-06-01

    This invention related to a circulating lithium-containing blanket system in a neution source hav'ing a magnetic field associated therewith. The blanket serves simultaneously and efficiently as a heat transfer mediunm and as a source of tritium. The blanket is composed of a lithium-6-enriched fused salt selected from the group consisting of lithium nitrite, lithium nitrate, a mixture of said salts, a mixture of each of said salts with lithium oxide, and a mixture of said salts with each other and with lithium oxide. The moderator, which is contained within the blanket in a separate conduit, can be water. A stellarator is one of the neutron sources which can be used in this invention. (AEC)

  17. Heat transfer characteristics of various kinds of ground heat exchangers for ground source heat pump system

    Science.gov (United States)

    Miyara, A.; Kariya, K.; Ali, Md. H.; Selamat, S. B.; Jalaluddin

    2017-01-01

    Three kinds of vertical-type ground heat exchangers, U-tube; double-tube; multi-tube, and two kinds of horizontal-type ground heat exchangers, standing Slinky; reclined Slinky, were experimentally and numerically investigated in order to clarify their heat transfer characteristics. Experiments and simulations were carried out under two operation conditions which are continuous operation mode and discontinuous operation mode and effects of temperature recovery and thermal storage on the heat transfer rate were shown. Differences of the heat transfer rate between standing Slinky and reclined Slinky were also indicated.

  18. Greenhouse gas emissions from domestic hot water: heat pumps compared to most commonly used systems

    OpenAIRE

    Hong, Bongghi; Howarth, Robert

    2017-01-01

    We estimate the emissions of the two most important greenhouse gasses (GHG), carbon dioxide (CO2) and methane (CH4), from the use of modern high-efficiency heat pump water heaters compared to the most commonly used domestic hot water systems: natural gas storage tanks, tankless natural gas demand heaters, electric resistance storage tanks, and tankless electric resistance heaters. We considered both natural gas-powered electric plants and coal-powered plants as the source of the electricity f...

  19. Heat pipe heat transport system for the Stirling Space Power Converter (SSPC)

    Science.gov (United States)

    Alger, Donald L.

    1992-08-01

    Life issues relating to a sodium heat pipe heat transport system are described. The heat pipe system provides heat, at a temperature of 1050 K, to a 50 kWe Stirling engine/linear alternator power converter called the Stirling Space Power Converter (SSPC). The converter is being developed under a National Aeronautics and Space Administration program. Since corrosion of heat pipe materials in contact with sodium can impact the life of the heat pipe, a literature review of sodium corrosion processes was performed. It was found that the impurity reactions, primarily oxygen, and dissolution of alloy elements were the two corrosion process likely to be operative in the heat pipe. Approaches that are being taken to minimize these corrosion processes are discussed.

  20. Study on a PCM heat storage system for rapid heat supply

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Jinjia; Kawaguchi, Yasuo; Hirano, Satoshi; Takeuchi, Hiromi [Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8564 (Japan)

    2005-12-01

    A thermal energy storage system employing phase change material (PCM) FNP-0090 (product of Nippon Seiro Co. Ltd.) for rapid heat discharge was studied numerically and experimentally. In the numerical studies, the PCM was encapsulated in four different capsules (sphere, cylinder, plate and tube) for investigating the effects of geometrical configurations. The effects of the capsule diameter and shell thickness and the void fraction on the performance of the heat storage system were also investigated. The experiment was conducted by using a commercial plate heat exchanger as the heat storage tank. It was found that the spherical capsule showed the best heat release performance among the four types of investigated capsules, whereas the tubular capsule with low void fraction was not ideal for rapid heat release of the thermal energy stored in the PCM. The heat release performance decreased in the order of sphere, cylinder, plate and tube. The numerical results and the experimental data agreed within 10%. (author)

  1. Lab-scale experiment of a closed thermochemical heat storage system including honeycomb heat exchanger

    International Nuclear Information System (INIS)

    Fopah-Lele, Armand; Rohde, Christian; Neumann, Karsten; Tietjen, Theo; Rönnebeck, Thomas; N'Tsoukpoe, Kokouvi Edem; Osterland, Thomas; Opel, Oliver

    2016-01-01

    A lab-scale thermochemical heat storage reactor was developed in the European project “thermal battery” to obtain information on the characteristics of a closed heat storage system, based on thermochemical reactions. The present type of storage is capable of re-using waste heat from cogeneration system to produce useful heat for space heating. The storage material used was SrBr 2 ·6H 2 O. Due to agglomeration or gel-like problems, a structural element was introduced to enhance vapour and heat transfer. Honeycomb heat exchanger was designed and tested. 13 dehydration-hydration cycles were studied under low-temperature conditions (material temperatures < 100 °C) for storage. Discharging was realized at water vapour pressure of about 42 mbar. Temperature evolution inside the reactor at different times and positions, chemical conversion, thermal power and overall efficiency were analysed for the selected cycles. Experimental system thermal capacity and efficiency of 65 kWh and 0.77 are respectively obtained with about 1 kg of SrBr 2 ·6H 2 O. Heat transfer fluid recovers heat at a short span of about 43 °C with an average of 22 °C during about 4 h, acceptable temperature for the human comfort (20 °C on day and 16 °C at night). System performances were obtained for a salt bed energy density of 213 kWh·m 3 . The overall heat transfer coefficient of the honeycomb heat exchanger has an average value of 147 W m −2  K −1 . Though promising results have been obtained, ameliorations need to be made, in order to make the closed thermochemical heat storage system competitive for space heating. - Highlights: • Lab-scale thermochemical heat storage is designed, constructed and tested. • The use of honeycomb heat exchanger as a heat and vapour process enhancement. • Closed system (1 kg SrBr 2 ·6H 2 O) able to give back 3/4 of initial thermal waste energy. • System storage capacity and thermal efficiency are respectively 65 kWh and 0.77.

  2. Freestanding, heat resistant microporous film for use in energy storage devices

    Energy Technology Data Exchange (ETDEWEB)

    Pekala, Richard W.; Cherukupalli, Srinivas; Waterhouse, Robert R.

    2018-02-20

    Preferred embodiments of a freestanding, heat resistant microporous polymer film (10) constructed for use in an energy storage device (70, 100) implements one or more of the following approaches to exhibit excellent high temperature mechanical and dimensional stability: incorporation into a porous polyolefin film of sufficiently high loading levels of inorganic or ceramic filler material (16) to maintain porosity (18) and achieve low thermal shrinkage; use of crosslinkable polyethylene to contribute to crosslinking the polymer matrix (14) in a highly inorganic material-filled polyolefin film; and heat treating or annealing of biaxially oriented, highly inorganic material-filled polyolefin film above the melting point temperature of the polymer matrix to reduce residual stress while maintaining high porosity. The freestanding, heat resistant microporous polymer film embodiments exhibit extremely low resistance, as evidenced by MacMullin numbers of less than 4.5.

  3. A Heat-Resistant and Energetic Metal-Organic Framework Assembled by Chelating Ligand.

    Science.gov (United States)

    Wang, Qianyou; Wang, Shan; Feng, Xiao; Wu, Le; Zhang, Guoying; Zhou, Mingrui; Wang, Bo; Yang, Li

    2017-11-01

    Heat-resistant explosives with high performance and insensitivity to external stimulus or thermal are indispensable in both the military and civilian worlds especially when utilized under harsh conditions. We designed and synthesized a new heat-resistant three-dimensional chelating energetic metal-organic framework (CEMOF-1) by employing 4-amino-4H-1,2,4-triazole-3,5-diol (ATDO) as a ligand. Because of its chelating 3D structural feature, good oxygen balance (-29.58%), and high crystal density (2.234 g cm -3 ), CEMOF-1 demonstrates high decomposition temperature (445 °C), insensitivity to stimulation, and excellent detonation velocity (10.05 km s -1 ) and detonation pressure (49.36 GPa). The advantages of facile synthesis, thermal stability, and powerful explosive performance make CEMOF-1 as a promising candidate for heat-resistant explosives in future applications.

  4. Heat resistance of an outbreak strain of Listeria monocytogenes in hot dog batter.

    Science.gov (United States)

    Mazzotta, A S; Gombas, D E

    2001-03-01

    The heat resistance of a strain of Listeria monocytogenes responsible for a listeriosis outbreak in hot dogs was not higher than the heat resistance of other L. monocytogenes strains when tested in tryptic soy broth and in laboratory-prepared hot dog batter. For the thermal death time experiments, the cells were grown to stationary phase or were starved in phosphate-buffered saline, pH 7, for 6 h at 30 degrees C. Starvation increased the heat resistance of L. monocytogenes in broth but not in hot dog batter. D-values in hot dog batter were higher than in broth. For the hot dog formulation used in this study, cooking the hot dog batter for 30 s at 71.1 degrees C (160 degrees F), or its equivalent using a z-value of 6 degrees C (11 degrees F), would inactivate 5 logs of L. monocytogenes.

  5. Effects of heat input on the pitting resistance of Inconel 625 welds by overlay welding

    Science.gov (United States)

    Kim, Jun Seok; Park, Young IL; Lee, Hae Woo

    2015-03-01

    The objective of this study was to establish the relationship between the dilution ratio of the weld zone and pitting resistance depending on the heat input to welding of the Inconel alloy. Each specimen was produced by electroslag welding using Inconel 625 as the filler metal. In the weld zone of each specimen, dendrite grains were observed near the fusion line and equiaxed grains were observed on the surface. It was also observed that a melted zone with a high Fe content was formed around the fusion line, which became wider as the welding heat input increased. In order to evaluate the pitting resistance, potentiodynamic polarization tests and CPT tests were conducted. The results of these tests confirmed that there is no difference between the pitting resistances of each specimen, as the structures of the surfaces were identical despite the effect of the differences in the welding heat input for each specimen and the minor dilution effect on the surface.

  6. A modeling approach for district heating systems with focus on transient heat transfer in pipe networks

    DEFF Research Database (Denmark)

    Mohammadi, Soma; Bojesen, Carsten

    2015-01-01

    Increasing the building energy efficiency in recent years results in noticeably reduction in their heating demand. Combined with the current trend for utilizing low temperature heat sources, it raises the necessity of introducing a new generation of district heating [DH] systems with lowered...... km pipelines (supply and return pipes). At the first stage, the Studstrup DH system is developed in TERMIS, which is commercial software for district heating system simulation, and then the developed model is validated and compared with the results obtained from TERMIS and measurements. The TERMIS...

  7. Roles of DNA repair and membrane integrity in heat resistance of Deinococcus radiodurans.

    Science.gov (United States)

    Bauermeister, Anja; Hahn, Claudia; Rettberg, Petra; Reitz, Günther; Moeller, Ralf

    2012-11-01

    To study the effects of heat shock on Deinococcus radiodurans and the role of DNA repair in high temperature resistance, different strains of D. radiodurans (wild type, recA, irrE, and pprA) were treated with temperatures ranging from 40 to 100 °C under wet and dry conditions. The mutant strains were more sensitive to wet heat of ≥60 °C and dry heat of ≥80 °C than the wild type. Both wild-type and DNA repair-deficient strains were much more resistant to high temperatures when exposed in the dried state as opposed to cells in suspension. Molecular staining techniques with the wild-type strain revealed that cells in the dried state were able to retain membrane integrity after drying and subsequent heat exposure, while heat-exposed cells in suspension showed significant loss of membrane integrity and respiration activity. The results suggest that the repair of DNA damage (e.g., DNA double-strand breaks by RecA and PprA) is essential after treatment with wet heat at temperatures >60 °C and dry heat >80 °C, and the ability of D. radiodurans to stabilize its plasma membrane during dehydration might represent one aspect in the protection of dried cells from heat-induced membrane damage.

  8. An innovative pool with a passive heat removal system

    International Nuclear Information System (INIS)

    Vitale Di Maio, Damiano; Naviglio, Antonio; Giannetti, Fabio; Manni, Fabio

    2012-01-01

    Heat removal systems are of primary importance in several industrial processes. As heat sink, a water pool or atmospheric air may be selected. The first solution takes advantage of high heat transfer coefficient with water but it requires active systems to maintain a constant water level; the second solution takes benefit from the unlimited heat removal capacity by air, but it requires a larger heat exchanger to compensate the lower heat transfer coefficient. In NPPs (nuclear power plants) during a nuclear reactor shutdown, as well as in some chemical plants to control runaway reactions, it is possible to use an innovative heat sink that joins the advantages of the two previous solutions. This solution is based on a special heat exchanger submerged in a water pool designed so that when heat removal is requested, active systems are not required to maintain the water level; due to the special design, when the pool is empty, atmospheric air becomes the only heat sink. The special heat exchanger design allows to have a heat exchanger without being oversized and to have a system able to operate for unlimited period without external interventions. This innovative system provides an economic advantage as well as enhanced safety features.

  9. On the interconnection between hydraulic resistance and heat transfer in porous media

    International Nuclear Information System (INIS)

    Kokorev, L.S.; Subbotin, V.I.; Fedoseev, V.N.; Khoritonov, V.V.; Voskobojnikov, V.V.

    1987-01-01

    Interconnection between coefficients of hydraulic resistance and heat transfer for turbulent flow in porous media has been established in the form of criterion equations containing a single empirical (apparently, universal) constant. This interconnection is based on the representation of a determining effect of velocity scale of coolant pulsation flow on a heat transfer coefficient value. It is discovered that the application of the Kholmogorov scale of pulsation velocity gives satisfactory results in porous media. Calculational results and experimental data on heat transfer in pebble-bed, netted and wiper media, in transversely streamlined rod clusters cooled with liquid metal, gases, water and oils have been compared. The application of the formulae derived is convenient for heat transfer evaluations in porous media from results of hydraulic resistance measurement

  10. Radiation and Heat Resistance of Moraxella-Acinetobacter in Meats

    Science.gov (United States)

    1978-01-23

    mechanism of resistance and their significance in food spoilage . MATERIALS AND EXPERIMENTAL PROCEDURES Plating and counting The plating and counting...appear to be important. They are not associated with food spoilage in presently accepted methods of processing, distribution, and storage. They only...1977. Comparative viability of unirradiated and gamma irradiated bacterial cells. J. Food Sei. 42: 1056. Maxcy, R. B., and N. P. Tiwari. 1973

  11. Heat exchangers for cardioplegia systems: in vitro study of four different concepts.

    Science.gov (United States)

    Drummond, Mário; Novello, Waldyr Parorali; de Arruda, Antonio Celso Fonseca; Braile, Domingo Marcolino

    2003-05-01

    The aim of this work is the evaluation of four different heat exchangers used for myocardium during cardioplegic system in cardiac surgeries. Four types of shell and tube heat exchangers made of different exchange elements were constructed, as follows: stainless steel tubes, aluminium tubes, polypropylene hollow fiber, and bellows type. The evaluation was performed by in vitro tests of parameters such as heat transfer, pressure drop, and hemolysis tendency. The result has shown that all four systems tested were able to achieve the heat performance, and to offer low resistance to flow, and safety, as well as have low tendency to hemolysis. However, we can emphasize that the bellows type heat exchanger has a significant difference with regard to the other three types.

  12. A multi-channel cooling system for multiple heat source

    Directory of Open Access Journals (Sweden)

    Xu Shanglong

    2016-01-01

    Full Text Available High-power electronic devices with multiple heating elements often require temperature uniformity and operating within their functional temperature range for optimal performance. A multi-channel cooling experiment apparatus is developed for studying heat removal inside an electronic device with multiple heat sources. It mainly consists of a computer-controlled pump, a multi-channel heat sink for multi-zone cooling and the apparatus for measuring the temperature and pressure drop. The experimental results show the system and the designed multi-channel heat sink structure can control temperature distribution of electronic device with multiple heat sources by altering coolant flow rate.

  13. Heat treatment of NiCrFe alloy to optimize resistance to intergrannular stress corrosion

    Science.gov (United States)

    Steeves, Arthur F.; Bibb, Albert E.

    1984-01-01

    A process of producing a NiCrFe alloy having a high resistance to stress corrosion cracking comprising heating a NiCrFe alloy to a temperature sufficient to enable the carbon present in the alloy body in the form of carbide deposits to enter into solution, rapidly cool the alloy body, and heat the cooled body to a temperature between 1100.degree. to 1500.degree. F. for about 1 to 30 hours.

  14. Effect of heat treatment on the grooving corrosion resistance of ERW pipes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Kwon; Lee, Jae Young; Lim, Soo Hyun; Park, Ji Hwan; Seo, Bo Min; Kim, Seon Hwa [Soonchunhyang University, Asan (Korea, Republic of)

    2002-06-15

    The v-sharp grooving corrosion of ERW(electrical resistance welding) steel pipes limited their wide application in the industry in spite of their high productivity and efficiency. The grooving corrosion is caused mainly by the different microstructures between the matrix and weld that is formed during the rapid heating and cooling cycle in welding. By this localized corrosion reaction of pipes, it evolves economic problems such as the early damage of industrial facilities and pipe lines of apartment, and water pollution. Even though the diminishing of sulfur content is most effective to decrease the susceptibility of grooving corrosion, it requires costly process. In this study, improvement of grooving corrosion resistance was pursuited by post weld heat treatment in the temperature range between 650 .deg. C and 950 .deg. C. Also, the effect of heat input in the welding was investigated. By employing chromnoamperometry and potentiodynamic experiment, the corrosion rate and grooving corrosion index({alpha}) were obtained. It was found that heat treatment could improve the grooving corrosion resistance. Among them, the heat treated at 900 .deg. C and 950 .deg. C had excellent grooving corrosion resistance. The index of heat treated specimen at 900 .deg. C and 950 .deg. C were 1.0, 1.2, respectively, which are almost immune to the grooving corrosion. Potential difference after the heat treatment, between base and weld metal was decreased considerably. While the as-received one measured 61{approx}71 mV, that of the 900 .deg. C heat treated steel pipe measured only 10mV. The results were explained and discussed

  15. Heat treatment of NiCrFe alloy 600 to optimize resistance to intergranular stress corrosion

    Science.gov (United States)

    Steeves, A.F.; Bibb, A.E.

    A process of producing a NiCrFe alloy having a high resistance to stress corrosion cracking comprises heating a NiCrFe alloy to a temperature sufficient to enable the carbon present in the alloy body in the form of carbide deposits to enter into solution, rapidly cooling the alloy body, and heating the cooled body to a temperature between 1100 to 1500/sup 0/F for about 1 to 30 hours.

  16. Surface Resistance Measurements and Estimate of the Beam-Induced Resistive Wall Heating of the LHC Dipole Beam Screen

    CERN Document Server

    Caspers, Friedhelm; Ruggiero, F; Tan, J

    1999-01-01

    An estimate of the resistive losses in the LHC beam screen is given from cold surface resistance measurements using the shielded pair technique, with particular emphasis on the effect of a high magnetic field. Two different copper coating methods, namely electro-deposition and co-lamination, have been evaluated. Experimental data are compared with theories including the anomalous skin effect and the magneto-resistance effect. It is shown whether the theory underestimates or not the losses depends strongly on the RRR value, on the magnetic field and on the surface characteristics. In the pessimistic case and for nominal machine parameters, the estimated beam-induced resistive wall heating can be as large as 260 mW/m for two circulating beams.

  17. The role of district heating in future renewable energy systems

    DEFF Research Database (Denmark)

    Lund, Henrik; Möller, Bernd; Mathiesen, Brian Vad

    2010-01-01

    heating options, including district heating as well as individual heat pumps and micro CHPs (Combined Heat and Power). The study includes almost 25 per cent of the Danish building stock, namely those buildings which have individual gas or oil boilers today and could be substituted by district heating......Based on the case of Denmark, this paper analyses the role of district heating in future Renewable Energy Systems. At present, the share of renewable energy is coming close to 20 per cent. From such point of departure, the paper defines a scenario framework in which the Danish system is converted...... to 100 per cent Renewable Energy Sources (RES) in the year 2060 including reductions in space heating demands by 75 per cent. By use of a detailed energy system analysis of the complete national energy system, the consequences in relation to fuel demand, CO2 emissions and cost are calculated for various...

  18. Thermodynamic analysis and performance assessment of an integrated heat pump system for district heating applications

    International Nuclear Information System (INIS)

    Soltani, Reza; Dincer, Ibrahim; Rosen, Marc A.

    2015-01-01

    A Rankine cycle-driven heat pump system is modeled for district heating applications with superheated steam and hot water as products. Energy and exergy analyses are performed, followed by parametric studies to determine the effects of varying operating conditions and environmental parameters on the system performance. The district heating section is observed to be the most inefficient part of system, exhibiting a relative irreversibility of almost 65%, followed by the steam evaporator and the condenser, with relative irreversibilities of about 18% and 9%, respectively. The ambient temperature is observed to have a significant influence on the overall system exergy destruction. As the ambient temperature decreases, the system exergy efficiency increases. The electricity generated can increase the system exergy efficiency at the expense of a high refrigerant mass flow rate, mainly due to the fact that the available heat source is low quality waste heat. For instance, by adding 2 MW of excess electricity on top of the targeted 6 MW of product heat, the refrigerant mass flow rate increases from 12 kg/s (only heat) to 78 kg/s (heat and electricity), while the production of 8 MW of product heat (same total output, but in form of heat) requires a refrigerant mass flow rate of only 16 kg/s. - Highlights: • A new integrated heat pump system is developed for district heating applications. • An analysis and assessment study is undertaken through exergy analysis methodology. • A comparative efficiency evaluation is performed for practical applications. • A parametric study is conducted to investigate how varying operating conditions and state properties affect energy and exergy efficiencies.

  19. Influence of Heat Treatment on Abrasive Wear Resistance of Silumin Matrix Composite Castings

    Directory of Open Access Journals (Sweden)

    Gawdzińska K.

    2016-03-01

    Full Text Available The authors attempted at examining the effect of heat treatment on abrasive wear resistance of metal composite castings. Metal matrix composites were made by infiltrating preforms created from unordered short fibers (graphite or silumin with liquid aluminium alloy AlSi12(b. Thus prepared composites were subject to solution heat treatment at a temperature of 520°C for four hours, then aging at a temperature of 220°C for four hours. Abrasion resistance of the material was tested before and after thermal treatment.

  20. Fire resistance of ultra-high performance fibre reinforced concrete due to heating and cooling

    Directory of Open Access Journals (Sweden)

    Nazri Fadzli Mohamed

    2017-01-01

    Full Text Available This study investigated the performance of ultra-high performance fibre reinforced concrete (UHPFRC at elevated temperatures. The specimens were exposed to high temperatures, specifically 200, 400, and 600 °C, for 2 h.The fire resistance performance of the specimens was classified on the basis of their compressive strength, spalling, and weight loss; residual strength after heating was also examined. Results showed that UHPFRC processes excellent fire resistance in terms of flame spread and fire growth. While strength loss was not significant at low temperatures, the specimen subjected to high temperature spalled severly and showed deterioration because of heat.

  1. Heat Saving Strategies in Sustainable Smart Energy Systems

    DEFF Research Database (Denmark)

    Lund, Henrik; Thellufsen, Jakob Zinck; Aggerholm, Søren

    2014-01-01

    This paper investigates to which extent heat should be saved rather than produced and to which extent district heating infrastructures, rather than individual heating solutions, should be used in future sustainable smart energy systems. Based on a concrete proposal to implement the Danish...

  2. Thermal Characteristics of an Oscillating Heat Pipe Cooling System for Electric Vehicle Li-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Ri-Guang Chi

    2018-03-01

    Full Text Available The heat generation of lithium ion batteries in electric vehicles (EVs leads to a degradation of energy capacity and lifetime. To solve this problem, a new cooling concept using an oscillating heat pipe (OHP is proposed. In the present study, an OHP has been adopted for Li-ion battery cooling. Due to the limited space in EVs, the cooling channel is installed on the bottom of the battery module. In the bottom cooling method with an OHP, generated heat can be dissipated easily and conveniently. However, most studies on heat pipes have used bottom heating and top or side cooling methods, so we investigate the various effects of parameters with a top heating/bottom cooling mode with the OHP, i.e., the inclination angle of the system, amount of working fluid charged, the heating amount, and the cold plate temperature with ethanol as a working fluid. The experimental results show that the thermal resistance (0.6 °C/W and uneven pulsating features influence the heat transfer performance. A heater used as a simulated battery was sustained under 60 °C under 10 W and 14 W heating conditions. This indicates that the proposed cooling system with the bottom cooling is feasible for use as an EV’s battery cooling system.

  3. Assessment of two-level heat pump installations’ power efficiency for heat supply systems

    Directory of Open Access Journals (Sweden)

    Аlla Е. Denysova

    2015-06-01

    Full Text Available The problem of energy saving becomes one of the most important in power engineering. It is caused by exhaustion of world reserves in hydrocarbon fuel, such as gas, oil and coal representing sources of traditional heat supply. Conventional sources has essential shortcomings: low power, ecological and economic efficiencies, that can be eliminated by using alternative methods of power supply, like the considered one: low-temperature natural heat of ground waters of on the basis of heat pump installations application. The heat supply system considered provides an effective use of two-level heat pump installation operating as heat source the Odessa city ground waters during the lowest ambient temperature period. Proposed is a calculation method of heat pump installations on the basis of geothermal heat supply. Calculated are the values of electric energy consumption N by the compressors’ drive, and the heat supply system transformation coefficient µ for a source of geothermal heat from ground waters of Odessa city allowing to estimate efficiency of two-level heat pump installations.

  4. Solar heating and domestic hot water system installed at Kansas City, Fire Stations, Kansas City, Missouri

    Science.gov (United States)

    1980-07-01

    The solar system was designed to provide 47 percent of the space heating, 8,800 square feet area and 75 percent of the domestic hot water (DHW) load. The solar system consists of 2,808 square feet of Solaron, model 2001, air, flat plate collector subsystem, a concrete box storage subsystem which contains 1,428 cubic feet of 0.5 inch diameter pebbles weighing 71.5 tons, a DHW preheat tank, blowers, pumps, heat exchangers, air ducting, controls and associated plumbing. Two 120 gallon electric DHW heaters supply domestic hot water which is preheated by the solar system. Auxiliary space heating is provided by three electric heat pumps with electric resistance heaters and four 30 kilowatt electric unit heaters. There are six modes of system operation.

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

    Science.gov (United States)

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

    2014-06-01

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

  6. Experimental investigation of a dual purpose solar heating system

    International Nuclear Information System (INIS)

    Nematollahi, Omid; Alamdari, Pourya; Assari, Mohammad Reza

    2014-01-01

    Highlights: • A dual purpose water and air heating system experimentally investigated. • This system can be used to heat water and air simultaneously. • Water can be used as a PCM material for heating air through the night. • Dual purpose systems achieve greater efficiency and lower heat dissipation. • Average efficiency of dual purpose system is 4% higher than single purpose system. - Abstract: In this study, a dual purpose water and air heating system is experimentally investigated. The system consists of a dual purpose flat solar collector and a vertical water storage tank. Water and air have natural and forced convection in the collector, respectively. The reason why dual purpose systems are used is to achieve greater efficiency and lower heat dissipation. Furthermore, high temperature and high performance can be obtained using this solar collector. These systems can be used to heat water and air simultaneously or separately. The hot water can be utilized for domestic applications or as a PCM material for heating air through the night. Besides, the hot air can be used in air conditioning systems, industrial processes and dryers. Therefore, using these collectors brings high energy savings. Absorber plate temperature variation, storage tank average temperature, system efficiency and air velocity effects are presented. Moreover, hourly efficiency is compared for single purpose and dual purpose systems. The results indicate that the efficiency of the dual purpose system is 3 to 5% higher than a single purpose system

  7. Heat pumps in urban space heating systems: Energy and environmental aspects

    International Nuclear Information System (INIS)

    Carlini, M.; Impero Abenavoli, R.; Rome Univ. La Sapienza

    1991-01-01

    A statistical survey is conducted of air pollution in the city of Rome (Italy) due to conventional building space heating systems burning fossil fuels. The survey identifies the annual consumption of the different fuels and the relative amounts of the various pollutants released into the atmosphere by the heating plants, e.g., sulfur and nitrogen oxides, carbon monoxide, etc. Comparisons are then made between the ratios of urban heating plant air pollutants produced per tonne of fuel employed and those for ENEL (Italian National Electricity Board) coal, oil and natural gas fired power plants, in order to demonstrate the better environmental performances of the utility operated energy plants. The building space heating system energy consumption and pollution data are then used in a cost benefit analysis favouring the retrofitting of conventional heating systems with heat pump systems to obtain substantial reductions in energy consumption, heating bills and urban air pollution. The use of readily available, competitively priced and low polluting (in comparison with fuel oil and coal) methane as the energy source for space heating purposes is recommended. The paper also notes the versatility of the heat pump systems in that they could also be used for summer air conditioning

  8. Indirect heating system for turbine anti-icing

    Energy Technology Data Exchange (ETDEWEB)

    Wagar, S.N.

    1980-03-01

    Gas-transmission service in northern Minnesota has verified the effectiveness of American Air Filter Co.'s indirect-heating method of preventing gas-turbine icing at compressor stations. By routing hot exhaust gases through a heat exchanger rather than directly into the inlet-air system, the indirect-heating method avoids turbine fouling, raises the air temperature at a constant specific humidity, and provides a uniform cross section of heated intake air for good turbine efficiency.

  9. Vapor Compression and Thermoelectric Heat Pump Heat Exchangers for a Condensate Distillation System: Design and Experiment

    Science.gov (United States)

    Erickson, Lisa R.; Ungar, Eugene K.

    2013-01-01

    Maximizing the reuse of wastewater while minimizing the use of consumables is critical in long duration space exploration. One of the more promising methods of reclaiming urine is the distillation/condensation process used in the cascade distillation system (CDS). This system accepts a mixture of urine and toxic stabilizing agents, heats it to vaporize the water and condenses and cools the resulting water vapor. The CDS wastewater flow requires heating and its condensate flow requires cooling. Performing the heating and cooling processes separately requires two separate units, each of which would require large amounts of electrical power. By heating the wastewater and cooling the condensate in a single heat pump unit, mass, volume, and power efficiencies can be obtained. The present work describes and compares two competing heat pump methodologies that meet the needs of the CDS: 1) a series of mini compressor vapor compression cycles and 2) a thermoelectric heat exchanger. In the paper, the system level requirements are outlined, the designs of the two heat pumps are described in detail, and the results of heat pump performance tests are provided. A summary is provided of the heat pump mass, volume and power trades and a selection recommendation is made.

  10. A heating system for piglets in farrowing house using waste heat from biogas engine

    Directory of Open Access Journals (Sweden)

    Payungsak Junyusen

    2008-12-01

    Full Text Available The aim of this study is to design and test a heating system for piglets in farrowing house by utilising the waste heat from a biogas engine as a heat source. The study was separated into three parts: the study on the biogas combined heat and power plant, the investigation on the properties of the heat panel, and the installation and testing of the heating system. From the experiment, the condition producing 60 kW of electrical power was a proper one, in which electrical efficiency and specific fuel consumption were 14% and 1.22 m3/kWh respectively. Generating both electricity and heat increased the overall efficiency to 37.7% and decreased the specific fuel consumption to 0.45 m3/kWh. The heat panel, which was made of a plastic material, had a thermal conductivity of 0.58 W/mC and the maximum compressive force and operating pressure of 8.1 kN and 0.35 bar respectively. The surface temperature of the panel was dependent on the inlet water temperature. When hot water of 44C was supplied into the farrowing house with room temperature of 26C, the average surface temperature was 33C. The developed heating system could provide heat for 4.3 farrowing houses. The payback period of this project was 2.5 years.

  11. Ohmic plasma heating in closed magnetic systems

    International Nuclear Information System (INIS)

    Suprunenko, V.A.; Gutarev, Yu.V.

    1979-01-01

    Presented is the analysis of experiments studying the energetic lifetime of electrons in stellarators with the Ohmic plasma heating. It is shown that at large magnitudes of the Ohmic heating current and of longitudinal magnetic field the influence of convective losses, connected with particle diffusion, becomes significant. In the experiments with the relatively low-temperature plasma the losses of heat essentially depend on the character of plasma electric conductivity and obey to the law similar to pseudoclassical one. The maximum value of electron energetic lifetime at the Ohmic heating of turbulent plasma is calculated. The relations obtained are in good agreement with experiments carried out on the existing stellarators

  12. BUYING BEHAVIOUR RELATED TO HEATING SYSTEMS IN GERMANY

    OpenAIRE

    Decker, Thomas; Zapilko, Marina; Menrad, Klaus

    2010-01-01

    The decision for buying a heating system is a long-term one, as many different aspects have an influence on this choice which were analysed in a Germany-wide, written survey. The respondents (only owners of a private house) had to answer questions about their attitude towards e.g. economics, convenience or ecological aspects related to heating systems and the respective combustibles. Using a multinomial logistic regression model the choice of the heating system is mainly explained by ecologic...

  13. Solar-heating and cooling system design package

    Science.gov (United States)

    1980-01-01

    Package of information includes design data, performance specifications, drawings, hazard analysis, and spare parts list for commercially produced system installed in single-family dwelling in Akron, Ohio. System uses air flat-plate collectors, 12000 kg rock storage and backup heat pump. Solar portion requires 0.7 kW, and provides 35% of average total heating load including hot water. Information aids persons considering installing solar home-heating systems.

  14. The heat-shock protein/chaperone network and multiple stress resistance.

    Science.gov (United States)

    Jacob, Pierre; Hirt, Heribert; Bendahmane, Abdelhafid

    2017-04-01

    Crop yield has been greatly enhanced during the last century. However, most elite cultivars are adapted to temperate climates and are not well suited to more stressful conditions. In the context of climate change, stress resistance is a major concern. To overcome these difficulties, scientists may help breeders by providing genetic markers associated with stress resistance. However, multistress resistance cannot be obtained from the simple addition of single stress resistance traits. In the field, stresses are unpredictable and several may occur at once. Consequently, the use of single stress resistance traits is often inadequate. Although it has been historically linked with the heat stress response, the heat-shock protein (HSP)/chaperone network is a major component of multiple stress responses. Among the HSP/chaperone 'client proteins', many are primary metabolism enzymes and signal transduction components with essential roles for the proper functioning of a cell. HSPs/chaperones are controlled by the action of diverse heat-shock factors, which are recruited under stress conditions. In this review, we give an overview of the regulation of the HSP/chaperone network with a focus on Arabidopsis thaliana. We illustrate the role of HSPs/chaperones in regulating diverse signalling pathways and discuss several basic principles that should be considered for engineering multiple stress resistance in crops through the HSP/chaperone network. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  15. Contribution of domestic heating systems to smart grid control

    DEFF Research Database (Denmark)

    Tahersima, Fatemeh; Stoustrup, Jakob; Meybodi, Soroush Afkhami

    2011-01-01

    How and to what extent, domestic heating systems can be helpful in regaining power balance in a smart grid, is the question to be answered in this paper. Our case study is an under-floor heating system supplied with a geothermal heat pump which is driven by electrical power from the grid. The idea...... is to deviate power consumption of the heat pump from its optimal value, in order to compensate power imbalances in the grid. Heating systems could be forced to consume energy, i.e. storing it in heat buffers when there is a power surplus in the grid; and be prevented from using power, in case of power shortage....... We have investigated how much power imbalance could be compensated, provided that a certain, yet user adjustable, level of residents' thermal comfort is satisfied. It is shown that the large heat capacity of the concrete floor alleviates undesired temperature fluctuations. Therefore, incorporating...

  16. Innovative system for delivery of low temperature district heating

    Directory of Open Access Journals (Sweden)

    Anton Ivanov Ianakiev

    2017-01-01

    Full Text Available An innovative Low Temperature District Heating (LTDH local network is developed in Nottingham, supported by REMOURBAN project, part of the H2020 Smart City and Community Lighthouse scheme. It was proposed that a branch emanating from the return pipe of the of the existing district heating system in Nottingham would be created to use low temperature heating for the first time in UK. The development is aimed to extract wasted (unused heat from existing district heating system and make it more efficient and profitable. Four maisonette blocks of 94 low-raised flats, at Nottingham demo site of the REMOURBAN project will be connected to this new LTDH system. The scheme will provide a primary supply of heat and hot water at approximately 50oC to 60oC. Innovated solutions have been put forward to overcome certain barriers, such as legionella related risks and peak loads during extreme heating seasons and occasional maintenance.

  17. A thermal plasmonic sensor platform: resistive heating of nanohole arrays.

    Science.gov (United States)

    Virk, Mudassar; Xiong, Kunli; Svedendahl, Mikael; Käll, Mikael; Dahlin, Andreas B

    2014-06-11

    We have created a simple and efficient thermal plasmonic sensor platform by letting a DC current heat plasmonic nanohole arrays. The sensor can be used to determine thermodynamic parameters in addition to monitoring molecular reactions in real-time. As an application example, we use the thermal sensor to determine the kinetics and activation energy for desorption of thiol monolayers on gold. Further, the temperature of the metal can be measured optically by the spectral shift of the bonding surface plasmon mode (0.015 nm/K). We show that this resonance shift is caused by thermal lattice expansion, which reduces the plasma frequency of the metal. The sensor is also used to determine the thin film thermal expansion coefficient through a theoretical model for the expected resonance shift.

  18. Retrofitting Combined Space and Water Heating Systems. Laboratory Tests

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, B. [NorthernStar Building America Partnership, St. Paul, MN (United States); Bohac, D. [NorthernStar Building America Partnership, St. Paul, MN (United States); Huelman, P. [NorthernStar Building America Partnership, St. Paul, MN (United States); Olsen, R. [NorthernStar Building America Partnership, St. Paul, MN (United States); Hewett, M. [NorthernStar Building America Partnership, St. Paul, MN (United States)

    2012-10-01

    Better insulated and tighter homes can often use a single heating plant for both space and domestic water heating. These systems, called dual integrated appliances (DIA) or combination systems, can operate at high efficiency and eliminate combustion safety issues associated by using a condensing, sealed combustion heating plant. Funds were received to install 400 DIAs in Minnesota low-income homes. The NorthernSTAR DIA laboratory was created to identify proper system components, designs, operating parameters, and installation procedures to assure high efficiency of field installed systems. Tests verified that heating loads up to 57,000 Btu/hr can be achieved with acceptable return water temperatures and supply air temperatures.

  19. Retrofitting Combined Space and Water Heating Systems: Laboratory Tests

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, B.; Bohac, D.; Huelman, P.; Olson, R.; Hewitt, M.

    2012-10-01

    Better insulated and tighter homes can often use a single heating plant for both space and domestic water heating. These systems, called dual integrated appliances (DIA) or combination systems, can operate at high efficiency and eliminate combustion safety issues associated by using a condensing, sealed combustion heating plant. Funds were received to install 400 DIAs in Minnesota low-income homes. The NorthernSTAR DIA laboratory was created to identify proper system components, designs, operating parameters, and installation procedures to assure high efficiency of field installed systems. Tests verified that heating loads up to 57,000 Btu/hr can be achieved with acceptable return water temperatures and supply air temperatures.

  20. 40 CFR 63.1409 - Heat exchange system provisions.

    Science.gov (United States)

    2010-07-01

    ... detect leaks. (2)(i) For recirculating heat exchange systems (cooling tower systems), the monitoring of...-through heat exchange systems, the monitoring of speciated HAP or total HAP refers to the HAP listed in... operator shall maintain, at all times, the monitoring plan that is currently in use. The current plan shall...

  1. Comprehensive thermodynamic analysis of a renewable energy sourced hybrid heating system combined with latent heat storage

    International Nuclear Information System (INIS)

    Utlu, Zafer; Aydın, Devrim; Kıncay, Olcay

    2014-01-01

    Highlights: • An experimental thermal investigation of hybrid renewable heating system is presented. • Analyses were done by using real data obtained from a prototype structure. • Exergy efficiency of system components investigated during discharging period are close to each other as 32%. • The average input energy and exergy rates to the LHS were 0.770 and 0.027 kW. • Overall total energy and exergy efficiencies of LHS calculated as 72% and 28.4%. - Abstract: In this study an experimental thermal investigation of hybrid renewable heating system is presented. Latent heat storage stores energy, gained by solar collectors and supplies medium temperature heat to heat pump both day time also night time while solar energy is unavailable. In addition to this an accumulation tank exists in the system as sensible heat storage. It provides supply–demand balance with storing excess high temperature heat. Analyses were done according to thermodynamic’s first and second laws by using real data obtained from a prototype structure, built as part of a project. Results show that high percent of heat loses took place in heat pump with 1.83 kW where accumulator-wall heating cycle followed it with 0.42 kW. Contrarily highest break-down of exergy loses occur accumulator-wall heating cycle with 0.28 kW. Averagely 2.42 kW exergy destruction took place in whole system during the experiment. Solar collectors and heat pump are the promising components in terms of exergy destruction with 1.15 kW and 1.09 kW respectively. Exergy efficiency of system components, investigated during discharging period are in a close approximately of 32%. However, efficiency of solar collectors and charging of latent heat storage are 2.3% and 7% which are relatively low. Average overall total energy and exergy efficiencies of latent heat storage calculated as 72% and 28.4% respectively. Discharging energy efficiency of latent heat storage is the highest through all system components. Also heat

  2. Conventional heating systems is heating with geothermal water, v. 15(60)

    International Nuclear Information System (INIS)

    Hadzhimishev, Dimitar; Gashteovski, Ljupcho; Shami, Jotso

    2007-01-01

    The Geothermal Energy (GE) is a new renewable energy source with many advantages and specifics. Present mainly application of GE is in agriculture. In Geothermal System Kochani the GE uses for district heating and industrial uses also. There are many problems to solve before using the geothermal energy for district heating: direct application feasibility for heating rooms and industrial using existing heating installation system (90/70°C); the level of heating needs covering without installation reconstruction; techno-economical justification of this reconstruction ; covering of pike heating needs. The answers of these enigmas you have in this written effort. The results were practically justified in about ten object in Kochani. (Author)

  3. Comparative technical-economic analysis of the low temperature heating systems

    International Nuclear Information System (INIS)

    Sharevski, Vasko; Sharevski, Milan

    1994-01-01

    A method for comparative technical-economic analysis between low temperature heating systems and heating systems with fossil fuel boiler plant, heat pump heating system and electrical heating systems is presented. The single and combined heating systems are analyzed. The technical-economic priority application of the heating system is determined according to the prices of the low temperature heat energy, fossil fuel heat energy, electrical energy, as well as to the coefficient of the annual use of the installed heating capacity, investment expenses, structure of the combined heating system and coefficient of performances of the heat pump. The combined heating system, composed with a low temperature heating subsystem, which is used to cover the base heat demands, and a oil boiler plant heating subsystem, for the top heat demands, have technical-economic justification and wide range of priority application, in comparison with single heating systems. (author)

  4. Magnetocaloric heat pump device, a heating or cooling system and a magnetocaloric heat pump assembly

    DEFF Research Database (Denmark)

    2014-01-01

    The invention provides a magnetocaloric heat pump device, comprising a magnetocaloric bed; a magnetic field source, the magnetocaloric bed and the magnetic field source being arranged to move relative to each other so as to generate a magnetocaloric refrigeration cycle within the heat pump, wherein...

  5. An experimental investigation devoted to determine heat transfer characteristics in a radiant ceiling heating system

    Science.gov (United States)

    Koca, Aliihsan; Acikgoz, Ozgen; Çebi, Alican; Çetin, Gürsel; Dalkilic, Ahmet Selim; Wongwises, Somchai

    2018-02-01

    Investigations on heated ceiling method can be considered as a new research area in comparison to the common wall heating-cooling and cooled ceiling methods. In this work, heat transfer characteristics of a heated radiant ceiling system was investigated experimentally. There were different configurations for a single room design in order to determine the convective and radiative heat transfer rates. Almost all details on the arrangement of the test chamber, hydraulic circuit and radiant panels, the measurement equipment and experimental method including uncertainty analysis were revealed in detail indicating specific international standards. Total heat transfer amount from the panels were calculated as the sum of radiation to the unheated surfaces, convection to the air, and conduction heat loss from the backside of the panels. Integral expression of the view factors was calculated by means of the numerical evaluations using Matlab code. By means of this experimental chamber, the radiative, convective and total heat-transfer coefficient values along with the heat flux values provided from the ceiling to the unheated surrounding surfaces have been calculated. Moreover, the details of 28 different experimental case study measurements from the experimental chamber including the convective, radiative and total heat flux, and heat output results are given in a Table for other researchers to validate their theoretical models and empirical correlations.

  6. The heat recovery with heat transfer methods from solar photovoltaic systems

    Science.gov (United States)

    Özakın, A. N.; Karsli, S.; Kaya, F.; Güllüce, H.

    2016-04-01

    Although there are many fluctuations in energy prices, they seems like rising day by day. Thus energy recovery systems have increasingly trend. Photovoltaic systems converts solar radiation directly into electrical energy thanks to semiconductors. But due to the nature of semiconductors, whole of solar energy cannot turn into electrical energy and the remaining energy turns into waste heat. The aim of this research is evaluate this waste heat energy by air cooling system. So, the energy efficiency of the system will be increased using appropriate heat transfer technologies such as fin, turbulator etc.

  7. LITERATURE REVIEW: HEAT TRANSFER THROUGH TWO-PHASE INSULATION SYSTEMS CONSISTING OF POWDERS IN A CONTINUOUS GAS PHASE

    Science.gov (United States)

    The report, a review of the literature on heat flow through powders, was motivated by the use of fine powder systems to produce high thermal resistivities (thermal resistance per unit thickness). he term "superinsulations" has been used to describe this type of material, which ha...

  8. Possibilities of heat energy recovery from greywater systems

    Science.gov (United States)

    Niewitecka, Kaja

    2018-02-01

    Waste water contains a large amount of heat energy which is irretrievably lost, so it is worth thinking about the possibilities of its recovery. It is estimated that in a residential building with full sanitary fittings, about 70% of the total tap water supplied is discharged as greywater and could be reused. The subject of the work is the opportunity to reuse waste water as an alternative source of heat for buildings. For this purpose, the design of heat exchangers used in the process of greywater heat recovery in indoor sewage systems, public buildings as well as in industrial plants has been reviewed. The possibility of recovering heat from waste water transported in outdoor sewage systems was also taken into consideration. An exemplary waste water heat recovery system was proposed, and the amount of heat that could be obtained using a greywater heat recovery system in a residential building was presented. The work shows that greywater heat recovery systems allow for significant savings in preheating hot tap water, and the rate of cost reimbursement depends on the purpose of the building and the type of installation. At the same time, the work shows that one should adjust the construction solutions of heat exchangers and indoor installations in buildings to the quality of the medium flowing, which is greywater.

  9. Possibilities of heat energy recovery from greywater systems

    Directory of Open Access Journals (Sweden)

    Niewitecka Kaja

    2018-01-01

    Full Text Available Waste water contains a large amount of heat energy which is irretrievably lost, so it is worth thinking about the possibilities of its recovery. It is estimated that in a residential building with full sanitary fittings, about 70% of the total tap water supplied is discharged as greywater and could be reused. The subject of the work is the opportunity to reuse waste water as an alternative source of heat for buildings. For this purpose, the design of heat exchangers used in the process of greywater heat recovery in indoor sewage systems, public buildings as well as in industrial plants has been reviewed. The possibility of recovering heat from waste water transported in outdoor sewage systems was also taken into consideration. An exemplary waste water heat recovery system was proposed, and the amount of heat that could be obtained using a greywater heat recovery system in a residential building was presented. The work shows that greywater heat recovery systems allow for significant savings in preheating hot tap water, and the rate of cost reimbursement depends on the purpose of the building and the type of installation. At the same time, the work shows that one should adjust the construction solutions of heat exchangers and indoor installations in buildings to the quality of the medium flowing, which is greywater.

  10. Computational design of heat resistant steels with evolving and time-independent strengthening factors

    NARCIS (Netherlands)

    Lu, Q.

    2015-01-01

    Alloy design by the traditional trial and error approach is known to be a time consuming and a highly cost procedure, especially for the design of heat resistant steel where the feedback time is intrinsically long. The significant developments in computational simulation techniques in the last

  11. Resistances for heat and mass transfer through a liquid–vapor interface in a binary mixture

    NARCIS (Netherlands)

    Glavatskiy, K.S.; Bedeaux, D.

    2010-01-01

    In this paper we calculate the interfacial resistances to heat and mass transfer through a liquid–vapor interface in a binary mixture. We use two methods, the direct calculation from the actual nonequilibrium solution and integral relations, derived earlier. We verify, that integral relations, being

  12. Modelling of Dynamic Transmission Cable Temperature Considering Soil-Specific Heat, Thermal Resistivity, and Precipitation

    DEFF Research Database (Denmark)

    Olsen, Rasmus; Anders, George J.; Holboell, Joachim

    2013-01-01

    This paper presents an algorithm for the estimation of the time-dependent temperature evolution of power cables, when real-time temperature measurements of the cable surface or a point within its vicinity are available. The thermal resistivity and specific heat of the cable surroundings are varied...

  13. Understanding decay resistance, dimensional stability and strength changes in heat treated and acetylated wood

    Science.gov (United States)

    Roger M. Rowell; Rebecca E. Ibach; James McSweeny; Thomas Nilsson

    2009-01-01

    Reductions in hygroscopicity, increased dimensional stability and decay resistance of heat-treated wood depend on decomposition of a large portion of the hemicelluloses in the wood cell wall. In theory, these hemicelluloses are converted to small organic molecules, water and volatile furan-type intermediates that can polymerize in the cell wall. Reductions in...

  14. Evaluating parameterizations of aerodynamic resistance to heat transfer using field measurements

    NARCIS (Netherlands)

    Liu, S.; Lu, L.; Mao, D.; Jia, L.

    2007-01-01

    Parameterizations of aerodynamic resistance to heat and water transfer have a significant impact on the accuracy of models of land - atmosphere interactions and of estimated surface fluxes using spectro-radiometric data collected from aircrafts and satellites. We have used measurements from an eddy

  15. Development of late blight resistance and heat tolerance through gamma irradiation of shoot cultures in potato

    International Nuclear Information System (INIS)

    Gosal, S.S.; Jitender Kaur, Adas; Minocha, J.L.

    2001-01-01

    In vitro shoot cultures of two potato varieties viz., Kufri jyoti and Kufri Chandramukhi were gamma irradiated at 20 Gy and 40 Gy. Micro tubers were induced in micro propagated M1V3 generation. For heat tolerance micro tubers were induced at elevated (28 C ) incubation temperature (optimum being 20 1C ) and were characterized by early sowing, chlorophyll persistence and harvest index. The number of micro tubers/plant was highly reduced at elevated temperature and the resulting tubers exhibited distorted shapes and growth of apical buds. Thus obtained micro tubers exhibited better germination (62.3%) even in early sowing at relatively higher temperature. The progenies from putative heat tolerant plants were grown in the field by sowing at higher temperature for four subsequent generations. Heat tolerant plants segregated in each generation but the frequency of heat tolerant plants increased in the advanced generation. For developing late blight resistance micro tubers produced from irradiated shoot cultures were sown in pots and resulting plants were screened using detached leaf method. The progenies of putative resistant plants grown in the field were artificially inoculated with sporangial inoculum of Phytophthora infection's. Field grown plants exhibited segregation with respect to disease reaction and about 56 per cent plants showed resistance. Segregation was reduced during following generation and the frequency of resistant plants was increased up to 72.3 per cent. Thus, repeated selections has helped in developing stable mutants in both the varieties

  16. The effect of recovery conditions on the apparent heat resistance of Bacillus cereus spores.

    Science.gov (United States)

    Gonzalez, I; Lopez, M; Mazas, M; Gonzalez, J; Bernardo, A

    1995-05-01

    The effect of recovery media and incubation temperature on the apparent heat resistance of three ATCC strains (4342, 7004 and 9818) of Bacillus cereus spores were studied. Nutrient Agar (NA), Tryptic Soy Agar (TSA), Plate Count Agar (PCA) and Milk Agar (MA) as the media and temperatures in the range of 15-40 degrees C were used to recover heated spores. Higher counts of heat injured spores were obtained on PCA and NA. The optimum subculture temperature was about 5 degrees C below the optimum temperature for unheated spores. No significant differences in heat resistance were observed with the different recovery conditions except for strains 4342 and 9818 when MA was used as plating medium. Large differences in D-values were found among the strains (D100 = 0.28 min for 7004; D100 = 0.99 min for 4342; D100 = 4.57 min for 9818). The 7004 strain showed a sub-population with a greater heat resistance. The z values obtained for the three strains studied under the different recovery conditions were similar (7.64 degrees C +/- 0.25).

  17. Fluctuation relation for heat exchange in Markovian open quantum systems

    Science.gov (United States)

    Ramezani, M.; Golshani, M.; Rezakhani, A. T.

    2018-04-01

    A fluctuation relation for the heat exchange of an open quantum system under a thermalizing Markovian dynamics is derived. We show that the probability that the system absorbs an amount of heat from its bath, at a given time interval, divided by the probability of the reverse process (releasing the same amount of heat to the bath) is given by an exponential factor which depends on the amount of heat and the difference between the temperatures of the system and the bath. Interestingly, this relation is akin to the standard form of the fluctuation relation (for forward-backward dynamics). We also argue that the probability of the violation of the second law of thermodynamics in the form of the Clausius statement (i.e., net heat transfer from a cold system to its hot bath) drops exponentially with both the amount of heat and the temperature differences of the baths.

  18. The research of direct heating solar seawater desalination system

    Energy Technology Data Exchange (ETDEWEB)

    Jiang Juyuan [Tianjin Univ. of Technology (China); Su Runxi [Tianjin Inst. of Seawater Desalination and Multipurpose Utilization, State Oceanic Administration, TJ (China); Xu Zhibin [Himin Solar Energy Group, SD (China); Cui Mingxian [Tianjin Univ. of Technology, TJ (China)

    2008-07-01

    The new seawater desalination technology of direct heating seawater by solar energy is put forward in this article. The solar energy collector is made of newly developed PPR mill micron material, which makes it corrosion-resistant and hardly deform less than 135 C, so as to guarantee its sealing. This new desalination technology combines flashing with MED, which makes it possible for seawater to be directly heated by solar energy. It also fits solar energy as an unsteady heat source. Besides, the operating conditions which avoid exchanger deposition are presented. Compared with traditional technology, it can save an exchanger, avoid temperature drop of heat exchanger, raise heat efficiency, and increase the production ratio by more than 10%. (orig.)

  19. Phase Change Material Systems for High Temperature Heat Storage

    OpenAIRE

    David Perraudin; Selmar Binder; Ehsan Rezai; Alberto Ortona; Sophia Haussener

    2015-01-01

    Efficient, cost effective, and stable high-temperature heat storage material systems are important in applications such as high-temperature industrial processes (metal processing, cement and glass manufacturing, etc.), or electricity storage using advanced adiabatic compressed air. Incorporating phase change media into heat storage systems provides an advantage of storing and releasing heat at nearly constant temperature, allowing steady and optimized operation of the downstream processes. Th...

  20. Heat transfer and mechanical interactions in fusion nuclear systems

    International Nuclear Information System (INIS)

    Nygren, R.E.

    1984-01-01

    This general review of design issues in heat transfer and mechanical interactions of the first wall, blanket and shield systems of tokamak and mirror fusion reactors begins with a brief introduction to fusion nuclear systems. The design issues are summarized in tables and the following examples are described to illustrate these concerns: the surface heating of limiters, heat transfer from solid breeders, MHD effects in liquid metal blankets, mechanical loads from electromagnetic transients and remote maintenance

  1. An investigation of energy efficient and sustainable heating systems for buildings : Combining photovoltaics with heat pump

    OpenAIRE

    Hesaraki, Arefeh; Holmberg, Sture

    2013-01-01

    Renewable energy sources contribute considerable amounts of energy when natural phenomena are converted into useful forms of energy. Solar energy, i.e. renewable energy, is converted to electricity by photovoltaic systems (PV). This study was aimed at investigating the possibility of combining PV with Heat Pump (HP) (PV-HP system). HP uses direct electricity to produce heat. In order to increase the sustainability and efficiency of the system, the required electricity for the HP was supposed ...

  2. Compatibility of heat resistant alloys with boron carbide, (2)

    International Nuclear Information System (INIS)

    Baba, Shin-ichi; Nagamatuya, Takaaki; Aoyama, Isao; Ito, Hisanori; Muraoka, Susumu.

    1982-12-01

    In the present design of the control rod for the experimental Very High Temperature Gas-cooled Reactor, sintered pellets of boron carbide mixed with graphite are used as a neutron absorber, which are clad with the sheath material of Hastelloy XR. The sintered pellet contains 30 wt% of natural boron. Chemical reaction occurs between the neutron absorber and the sheath material when they contact mutually at elevated temperature. The term called compatibility is defined as the ability of those materials to be used together without undesirable reaction, in this report. The experimental results on the compatibility of both materials are presented and are discussed on three subjects as (1) the comparison between Hastelloy X and Hastelloy XR, (2) the long term exposure, (3) the effect of the reaction barrier. No difference was observed between Hastelloy X and Hastelloy XR within the conditions of the experiment at 850 0 C, 950 0 C and 1050 0 C for each 100 h concerning the first subject. On the second, the penetration depth of 74 um and 156 um were observed on Hastelloy X reacted with sintered pellets (boron carbide and graphite) at 750 0 C for 3000 h and 850 0 C for 2000 h, respectively. On the third subject, Hastelloy X surfaces were coated with zirconia or alumina powder by plasma spraying process and by calorizing process in order to prevent the above mentioned reaction. These specimens were tested under two conditions: the one was a simple heat test of 1000 0 C - 100 h and the other was five thermal cycles of 1000 0 C - 20 h. The test results showed that no reaction occurred in the both alloys themselves and some of the coated layers were stripped or cracked. (author)

  3. External costs and taxes in heat supply systems

    International Nuclear Information System (INIS)

    Karlsson, Aasa; Gustavsson, Leif

    2003-01-01

    A systems approach was used to compare different heating systems from a consumer perspective. The whole energy system was considered from natural resources to the required energy services. District heating, electric heat pumps, electric boilers, natural-gas-, oil- or pellet-fired local boilers were considered when supplying heat to a detached house. The district heat production included wood-chip-fired and natural-gas-fired cogeneration plants. Electricity other than cogenerated electricity was produced in wood-chip- and natural-gas-fired stand-alone power plants. The analysis includes four tax scenarios, as well as the external cost of environmental and health damage arising from energy conversion emission based on the ExternE study of the European Commission. The most cost-efficient systems were the natural-gas and oil boiler systems, followed by the heat pump and district heating systems, when the external cost and taxes were excluded. When including the external costs of CO 2 emission, the wood-fuel-based systems were much more cost efficient than the fossil-fuel-based systems, also when CO 2 capture and storage were applied. The external costs are, however, highly uncertain. Taxes steer towards lowering energy use and lowering CO 2 emission if they are levied solely on all the fossil-fuel-related emission and fuel use in the systems. If consumer electricity and heat taxes are used, the taxes have an impact on the total cost, regardless of the fuel used, thereby benefiting fuel-based local heating systems. The heat pump systems were the least affected by taxes, due to their high energy efficiency. The electric boiler systems were the least cost-efficient systems, also when the external cost and taxes were included

  4. Nanoemulsified D-Limonene Reduces the Heat Resistance of Salmonella Senftenberg over 50 Times.

    Science.gov (United States)

    Ros-Chumillas, María; Garre, Alberto; Maté, Javier; Palop, Alfredo; Periago, Paula M

    2017-03-15

    Salmonella Senftenberg is a pathogen agent causative of foodborne disease and it is considered the most heat-resistant serovar within this genus. Food industries use heat treatment and chemical antimicrobials in order to eliminate this microorganism in food, but consumers prefer natural antimicrobials as essential oils and their components. This study evaluates the combined effect of thermal treatments and different concentrations of D -limonene nanoemulsion on the inactivation of Salmonella ( S. ) Senftenberg. The results showed an important effect of the nanoemulsified D -limonene on the heat resistance of S. Senftenberg. The δ 50 °C value was reduced by 85%, 96% and 98% when 0.1, 0.5 and 1 mM of nanoemulsified D -limonene was added to the heating medium. The effect was kept along all the heating temperatures researched and the shape of the survival curves did not change with the addition of the antimicrobial. The results obtained in this research could be very useful for food industries for optimizing or improving heat treatments applied to food.

  5. Nanoemulsified D-Limonene Reduces the Heat Resistance of Salmonella Senftenberg over 50 Times

    Directory of Open Access Journals (Sweden)

    María Ros-Chumillas

    2017-03-01

    Full Text Available Salmonella Senftenberg is a pathogen agent causative of foodborne disease and it is considered the most heat-resistant serovar within this genus. Food industries use heat treatment and chemical antimicrobials in order to eliminate this microorganism in food, but consumers prefer natural antimicrobials as essential oils and their components. This study evaluates the combined effect of thermal treatments and different concentrations of D-limonene nanoemulsion on the inactivation of Salmonella (S. Senftenberg. The results showed an important effect of the nanoemulsified D-limonene on the heat resistance of S. Senftenberg. The δ50 °C value was reduced by 85%, 96% and 98% when 0.1, 0.5 and 1 mM of nanoemulsified D-limonene was added to the heating medium. The effect was kept along all the heating temperatures researched and the shape of the survival curves did not change with the addition of the antimicrobial. The results obtained in this research could be very useful for food industries for optimizing or improving heat treatments applied to food.

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

    Directory of Open Access Journals (Sweden)

    V. A. Sednin

    2009-01-01

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

  7. Heating and Domestic Hot Water Systems in Buildings Supplied by Low-Temperature District Heating

    DEFF Research Database (Denmark)

    Brand, Marek

    leads to up to 56% greater heat demand than values suggested in the Danish national calculation tool Be10, and in 40% lower connection power than for an SH system dimensioned in accordance with DS 418. Use of Be10 input data in cost-effectiveness analyses for DH networks therefore means worse results......, because less heat is sold to customers and there is higher heat loss in the network. Similarly, higher connection power than needed means bigger pipe diameters are needed, resulting in higher heat losses as well. Using realistic values is therefore very important for feasibility calculations of DH.  ...

  8. Agent-based modelling of heating system adoption in Norway

    Energy Technology Data Exchange (ETDEWEB)

    Sopha, Bertha Maya; Kloeckner, Christian A.; Hertwich, Edgar G.

    2010-07-01

    Full text: This paper introduces agent-based modelling as a methodological approach to understand the effect of decision making mechanism on the adoption of heating systems in Norway. The model is used as an experimental/learning tool to design possible interventions, not for prediction. The intended users of the model are therefore policy designers. Primary heating system adoptions of electric heating, heat pump and wood pellet heating were selected. Random topology was chosen to represent social network among households. Agents were households with certain location, number of peers, current adopted heating system, employed decision strategy, and degree of social influence in decision making. The overall framework of decision-making integrated theories from different disciplines; customer behavior theory, behavioral economics, theory of planned behavior, and diffusion of innovation, in order to capture possible decision making processes in households. A mail survey of 270 Norwegian households conducted in 2008 was designed specifically for acquiring data for the simulation. The model represents real geographic area of households and simulates the overall fraction of adopted heating system under study. The model was calibrated with historical data from Statistics Norway (SSB). Interventions with respects to total cost, norms, indoor air quality, reliability, supply security, required work, could be explored using the model. For instance, the model demonstrates that a considerable total cost (investment and operating cost) increase of electric heating and heat pump, rather than a reduction of wood pellet heating's total cost, are required to initiate and speed up wood pellet adoption. (Author)

  9. Nuclear district heating system with a high-temperature reactor

    International Nuclear Information System (INIS)

    Schroeder, G.; Barnert, H.; Wischnewski, R.

    1978-01-01

    From the demand viewpoint, the connection of an installed nuclear thermal capacity of 290 MJ/s for district heating purposes would be possible in the central Ruhr District by 1982-1983. The nuclear district heating system is made up of several subsystems, for instance, a smaller size high-temperature reactor [500 MW(thermal)] as a nuclear heat-and-power plant and an interconnected district heating system with a feed temperature of 453 K (180 0 C). The expenditure for additional investments, additional fuel costs, and costs for substitute power capacity are charged to the thermal energy generation costs of the nuclear heat-and-power plant. For the nuclear district heating system, the district heating costs to the consumer will vary over wide limits, depending on local conditions, between 7.8 and 12.2 $/GJ at the commissioning date in 1983, assuming that all subsystems have to be newly installed. These costs can be lower than district heating costs in a conventional district heating system with fossil-fired heating stations

  10. Experiments on novel solar heating and cooling system

    International Nuclear Information System (INIS)

    Wang Yiping; Cui Yong; Zhu Li; Han Lijun

    2008-01-01

    Solar heating and nocturnal radiant cooling techniques are united to produce a novel solar heating and cooling system. The radiant panel with both heating and cooling functions can be used as structural materials for the building envelope, which realizes true building integrated utilization of solar energy. Based on the natural circulation principle, the operation status can be changed automatically between the heating cycle and the cooling cycle. System performances under different climate conditions using different covers on the radiant panel are studied. The results show that the novel solar heating and cooling system has good performance of heating and cooling. For the no cover system, the daily average heat collecting efficiency is 52% with the maximum efficiency of 73%, while at night, the cooling capacity is about 47 W/m 2 on a sunny day. On a cloudy day, the daily average heat collecting efficiency is 47% with the maximum of 84%, while the cooling capacity is about 33 W/m 2 . As a polycarbonate (PC) panel or polyethylene film are used as covers, the maximum heat collecting efficiencies are 75% and 72% and the daily average heat collecting efficiencies are 61% and 58%, while the cooling capacities are 50 W/m 2 and 36 W/m 2 , respectively

  11. Characterization of a mini-channel heat exchanger for a heat pump system

    Science.gov (United States)

    Arteconi, A.; Giuliani, G.; Tartuferi, M.; Polonara, F.

    2014-04-01

    In this paper a mini-channel aluminum heat exchanger used in a reversible heat pump is presented. Mini-channel finned heat exchangers are getting more and more interest for refrigeration systems, especially when compactness and low refrigerant charge are desired. Purpose of this paper was to characterize the mini-channel heat exchanger used as evaporator in terms of heat transfer performance and to study the refrigerant distribution in the manifold. The heat exchanger characterization was performed experimentally by means of a test rig built up for this purpose. It is composed of an air-to-air heat pump, air channels for the external and internal air circulation arranged in a closed loop, measurement sensors and an acquisition system. The overall heat transfer capacity was assessed. Moreover, in order to characterize the flow field of the refrigerant in the manifold of the heat exchanger, a numerical investigation of the fluid flow by means of CFD was performed. It was meant to evaluate the goodness of the present design and to identify possible solutions for the future improvement of the manifold design.

  12. ELECTRICAL RESISTANCE HEATING OF SOILS AT C-REACTOR AT THE SAVANNAH RIVER SITE

    Energy Technology Data Exchange (ETDEWEB)

    Blundy, R; Michael Morgenstern, M; Joseph Amari, J; Annamarie MacMurray, A; Mark Farrar, M; Terry Killeen, T

    2007-09-10

    Chlorinated solvent contamination of soils and groundwater is an endemic problem at the Savannah River Site (SRS), and originated as by-products from the nuclear materials manufacturing process. Five nuclear reactors at the SRS produced special nuclear materials for the nation's defense program throughout the cold war era. An important step in the process was thorough degreasing of the fuel and target assemblies prior to irradiation. Discharges from this degreasing process resulted in significant groundwater contamination that would continue well into the future unless a soil remediation action was performed. The largest reactor contamination plume originated from C-Reactor and an interim action was selected in 2004 to remove the residual trichloroethylene (TCE) source material by electrical resistance heating (ERH) technology. This would be followed by monitoring to determine the rate of decrease in concentration in the contaminant plume. Because of the existence of numerous chlorinated solvent sources around SRS, it was elected to generate in-house expertise in the design and operation of ERH, together with the construction of a portable ERH/SVE system that could be deployed at multiple locations around the site. This paper describes the waste unit characteristics, the ERH system design and operation, together with extensive data accumulated from the first deployment adjacent to the C-Reactor building. The installation heated the vadose zone down to 62 feet bgs over a 60 day period during the summer of 2006 and raised soil temperatures to over 200 F. A total of 730 lbs of trichloroethylene (TCE) were removed over this period, and subsequent sampling indicated a removal efficiency of 99.4%.

  13. Performance study of heat-pipe solar photovoltaic/thermal heat pump system

    International Nuclear Information System (INIS)

    Chen, Hongbing; Zhang, Lei; Jie, Pengfei; Xiong, Yaxuan; Xu, Peng; Zhai, Huixing

    2017-01-01

    Highlights: • The testing device of HPS PV/T heat pump system was established by a finished product of PV panel. • A detailed mathematical model of heat pump was established to investigate the performance of each component. • The dynamic and static method was combined to solve the mathematical model of HPS PV/T heat pump system. • The HPS PV/T heat pump system was optimized by the mathematical model. • The influence of six factors on the performance of HPS PV/T heat pump system was analyzed. - Abstract: A heat-pipe solar (HPS) photovoltaic/thermal (PV/T) heat pump system, combining HPS PV/T collector with heat pump, is proposed in this paper. The HPS PV/T collector integrates heat pipes with PV panel, which can simultaneously generate electricity and thermal energy. The extracted heat from HPS PV/T collector can be used by heat pump, and then the photoelectric conversion efficiency is substantially improved because of the low temperature of PV cells. A mathematical model of the system is established in this paper. The model consists of a dynamic distributed parameter model of the HPS PV/T collection system and a quasi-steady state distributed parameter model of the heat pump. The mathematical model is validated by testing data, and the dynamic performance of the HPS PV/T heat pump system is discussed based on the validated model. Using the mathematical model, a reasonable accuracy in predicting the system’s dynamic performance with a relative error within ±15.0% can be obtained. The capacity of heat pump and the number of HPS collectors are optimized to improve the system performance based on the mathematical model. Six working modes are proposed and discussed to investigate the effect of solar radiation, ambient temperature, supply water temperature in condenser, PV packing factor, heat pipe pitch and PV backboard absorptivity on system performance by the validated model. It is found that the increase of solar radiation, ambient temperature and PV

  14. Solar heating system at Quitman County Bank, Marks, Mississippi

    Science.gov (United States)

    1980-01-01

    Information on the Solar Energy Heating System installed in a single story wood frame, cedar exterior, sloped roof building is presented. The system has on-site temperature and power measurements readouts. The 468 square feet of Solaron air flat plate collectors provide for 2,000 square feet of space heating, an estimated 60 percent of the heating load. Solar heated air is distributed to the 235 cubic foot rock storage box or to the load (space heating) by a 960 cubic feet per minute air handler unit. A 7.5 ton Carrier air-to-air heat pump with 15 kilowatts of electric booster strips serve as a back-up (auxiliary) to the solar system. Motorized dampers control the direction of airflow and back draft dampers prevent thermal siphoning of conditioned air.

  15. Performance testing and certification of small solar heating systems

    NARCIS (Netherlands)

    Pauschinger, Th.

    1996-01-01

    Performance testing and certification of solar heating systems are taking the step from research to practical use. This is shown by the increasing activities on this field on several European markets and, even more clearly, by the Draft European Standards (prEN) for solar heating systems, which will

  16. Assessment of the role of oxygen and mitochondria in heat shock induction of radiation and thermal resistance in Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Mitchel, R.E.J.; Morrison, D.P.

    1983-01-01

    In response to a heat shock, the yeast Saccharomyces cerevisiae undergoes a large increase in its resistance to heat and, by the induction of its recombinational DNA repair capacity, a corresponding increase in resistance to radiation. Yeast which lack mitochondrial DNA, mitochondria-controlled protein synthetic apparatus, aerobic respiration, and electron transport (rho 0 strain) were used to assess the role of O 2 , mitochondria, and oxidative processes controlled by mitochondria in the induction of these resistances. We have found that rho 0 yeast grown and heat shocked in either the presence or absence of O 2 are capable of developing both radiation and heat resistance. We conclude that neither the stress signal nor its cellular consequences of induced heat and radiation resistance are directly dependent on O 2 , mitochondrial DNA, or mitochondria-controlled protein synthetic or oxidative processes

  17. Energy savings for solar heating systems; Solvarmeanlaegs energibesparelser

    Energy Technology Data Exchange (ETDEWEB)

    Furbo, S.; Fan, J.

    2011-01-15

    Energy savings for a number of new solar heating systems in one family houses have been determined by means of information on the energy consumption of the houses before and after installation of the solar heating systems. The investigated solar heating systems are marketed by Velux Danmark A/S, Sonnnenkraft Scandinavia A/S and Batec Solvarme A/S. Solar domestic hot water systems as well as solar combi systems are included in the investigations The houses have different auxiliary energy supply systems: Natural gas boilers, oil fired burners, electrical heating and district heating. Some of the houses have a second auxiliary energy supply system. The collector areas vary from 1.83 m{sup 2} to 9.28 m{sup 2}. Some of the solar heating systems are based on energy units with a new integrated natural gas boiler and a heat storage for the solar heating system. The existing energy systems in the houses are for most of the houses used as the auxiliary energy systems for the solar heating systems. The yearly energy savings for the houses where the only change is the installation of the solar heating system vary from 300 kWh per m{sup 2} solar collector to 1300 kWh per m{sup 2} solar collector. The average yearly energy savings is about 670 kWh per m{sup 2} solar collector for these solar heating systems. The energy savings per m{sup 2} solar collector are not influenced by the solar heating system type, the company marketing the system, the auxiliary energy supply system, the collector area, the collector tilt, the collector azimuth, the energy consumption of the house or the location of the house. The yearly energy savings for the houses with solar heating systems based on energy units including a new natural gas boiler vary from 790 kWh per m{sup 2} solar collector to 2090 kWh per m{sup 2} solar collector. The average yearly energy savings is about 1520 kWh per m{sup 2} solar collector for these solar heating systems. The energy savings per m{sup 2} solar collector for

  18. Heat-resistance of Hamigera avellanea and Thermoascus crustaceus isolated from pasteurized acid products.

    Science.gov (United States)

    Scaramuzza, Nicoletta; Berni, Elettra

    2014-01-03

    Products containing sugar or fruit derivatives are usually subjected to a pasteurization process that can anyway be ineffective to kill ascospores from heat-resistant molds. Although the most occurring and economically relevant heat-resistant species belong to Byssochlamys, Neosartorya, Talaromyces, and Eupenicillium genera, an increasing number of uncommon heat-resistant isolates have been recently detected as spoiling microorganisms in such products. Since Hamigera spp. and Thermoascus spp. were those more frequently isolated at SSICA, heat resistance of Hamigera avellanea and Thermoascus crustaceus strains from pasteurized acid products was studied in apple juice, in blueberry and grape juice and in a buffered glucose solution. Data obtained from thermal death curves and statistical elaboration of raw data showed that D values of H. avellanea may vary between 11.11 and 66.67 min at 87°C, between 4.67 and 13.51 at 90°C, and between 0.43 and 1.52 min at 95°C. Similarly, D values of T. crustaceus may vary between 18.52 and 90.91 min at 90°C, between 2.79 and 19.23 at 93°C, and between 1.11 and 2.53 min at 95°C. For both strains studied, the z-values calculated from the decimal reduction time curves did not prove to be significantly influenced by the heating medium, that being 4.35°C, 5.39°C or 5.27°C for H. avellanea and 4.42°C, 3.69°C or 3.37°C for T. crustaceus, respectively in apple juice, in blueberry and grape juice or in the buffered glucose solution. Considering the pasteurization treatments industrially applied to fruit-based foods, the variation of thermal parameters does not seem to be a possible way to avoid product spoilage by these two species and only good practices applied to reduce the original load of heat-resistant fungi can help producers to prevent losses in contaminated finished products, as usually happens for other heat resistant molds. © 2013 Elsevier B.V. All rights reserved.

  19. Study of an active wall solar heating system

    International Nuclear Information System (INIS)

    Kassem, Talal

    2006-01-01

    An active wall solar heating system was built and tested. In the same time a compatible computer program has been according to set the recommended dimensions for the solar collectors where (F-Chart) method used to set the ratio of monthly solar sharing average for the examined heating system. Some parameters, such as collectors' areas, its tilt angle and near earth reflecting were experimentally investigated, affecting the executed active solar heating system performance. The study explain the ability of using this system which is simple, Low coast and high performance in heating residential and public buildings and heating water with ratio of yearly solar sharing achieves the needed saving of using this system.(Author)

  20. Increase of COP for heat transformer in water purification systems. Part I - Increasing heat source temperature

    International Nuclear Information System (INIS)

    Siqueiros, J.; Romero, R.J.

    2007-01-01

    The integration of a water purification system in a heat transformer allows a fraction of heat obtained by the heat transformer to be recycled, increasing the heat source temperature. Consequently, the evaporator and generator temperatures are also increased. For any operating conditions, keeping the condenser and absorber temperatures and also the heat load to the evaporator and generator, a higher value of COP is obtained when only the evaporator and generator temperatures are increased. Simulation with proven software compares the performance of the modeling of an absorption heat transformer for water purification (AHTWP) operating with water/lithium bromide, as the working fluid-absorbent pair. Plots of enthalpy-based coefficients of performance (COP ET ) and the increase in the coefficient of performance (COP) are shown against absorber temperature for several thermodynamic operating conditions. The results showed that proposed (AHTWP) system is capable of increasing the original value of COP ET more than 120%, by recycling part of the energy from a water purification system. The proposed system allows to increase COP values from any experimental data for water purification or any other distillation system integrated to a heat transformer, regardless of the actual COP value and any working fluid-absorbent pair

  1. Advanced impedance matching system for ICRF heating using innovative twin stub tuner and frequency variation

    Science.gov (United States)

    Kumazawa, R.; Saito, K.; Kasahara, H.; Seki, T.; Mutoh, T.; Shimpo, F.; Nomura, G.; Kato, A.; Okada, H.; Zhao, Y.; Kwak, J. G.; Yoon, J. S.

    2008-11-01

    Ion cyclotron range of frequency (ICRF) heating has been a reliable tool for steady-state plasma heating with high RF power of several tens of megawatts. However, a sudden increase in the reflected RF power during ICRF heating experiments with ELMy H-mode plasmas is an issue which must be solved for future fusion experimental devices or fusion reactors. This paper describes an innovative ICRF heating system using a frequency feedback control to reduce the reflected power in response to the rapid change in the plasma impedance in the ELMy H-mode plasma. A twin stub tuner has been newly invented for this purpose. The feasibility of keeping the reflected RF power fraction at a low level, e.g. 1%, is demonstrated even with a large change in plasma resistance, e.g. 2 ~ 8Ω. Calculated and experimental results are presented for the conventional double stub tuner impedance matching system equipped with the twin stub tuner.

  2. Advanced impedance matching system for ICRF heating using innovative twin stub tuner and frequency variation

    International Nuclear Information System (INIS)

    Kumazawa, R.; Saito, K.; Kasahara, H.; Seki, T.; Mutoh, T.; Shimpo, F.; Nomura, G.; Kato, A.; Okada, H.; Zhao, Y.; Kwak, J.G.; Yoon, J.S.

    2008-01-01

    Ion cyclotron range of frequency (ICRF) heating has been a reliable tool for steady-state plasma heating with high RF power of several tens of megawatts. However, a sudden increase in the reflected RF power during ICRF heating experiments with ELMy H-mode plasmas is an issue which must be solved for future fusion experimental devices or fusion reactors. This paper describes an innovative ICRF heating system using a frequency feedback control to reduce the reflected power in response to the rapid change in the plasma impedance in the ELMy H-mode plasma. A twin stub tuner has been newly invented for this purpose. The feasibility of keeping the reflected RF power fraction at a low level, e.g. 1%, is demonstrated even with a large change in plasma resistance, e.g. 2 ∼ 8Ω. Calculated and experimental results are presented for the conventional double stub tuner impedance matching system equipped with the twin stub tuner.

  3. Preliminary design package for prototype solar heating system

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

    A summary is given of the preliminary analysis and design activity on solar heating systems. The analysis was made without site specific ata other than weather; therefore, the results indicate performance expected under these special conditions. Major items in this report include systeem candidates, design approaches, trade studies and other special data required to evaluate the preliminary analysis and design. The program calls for the development and delivery of eight prototype solar heating and coolin systems for installation and operational test. Two-heating and six heating and cooling units will be delivered for Single Family Residences (SFR), Multi-Family Residences (MFR) and commercial applications.

  4. Conversion to biofuel based heating systems - local environmental effects

    International Nuclear Information System (INIS)

    Jonsson, Anna

    2003-01-01

    One of the most serious environmental problems today is the global warming, i.e.climate changes caused by emissions of greenhouse gases. The greenhouse gases originate from combustion of fossil fuels and changes the atmospheric composition. As a result of the climate change, the Swedish government has decided to make a changeover of the Swedish energy system. This involves an increase of the supply of electricity and heating from renewable energy sources and a decrease in the amount electricity used for heating, as well as a more efficient use of the existing electricity system. Today, a rather large amount electricity is used for heating in Sweden. Furthermore, nuclear power will be phased out by the year 2010 in Sweden. Bio fuels are a renewable energy source and a conceivable alternative to the use of fossil fuels. Therefore, an increase of bio fuels will be seen the coming years. Bio fuels have a lot of environmental advantages, mainly for the global environment, but might also cause negative impacts such as depletion of the soils where the biomass is grown and local deterioration of the air quality where the bio fuels are combusted. These negative impacts are a result of the use of wrong techniques and a lack of knowledge and these factors have to be improved if the increase of the use of bio fuels is to be made effectively. The aim of this master thesis is to evaluate the possibilities for heating with bio fuel based systems in housing areas in the municipalities of Trollhaettan, Ulricehamn and Goetene in Vaestra Goetalands County in the South West of Sweden and to investigate which environmental and health effects are caused by the conversion of heating systems. The objective is to use the case studies as examples on preferable bio fuel based heating systems in different areas, and to what environmental impact this conversion of heating systems might cause. The housing areas for this study have been chosen on the basis of present heating system, one area

  5. Identification of Heat Transfer Resistance of Scale Deposit on theEvaporator of Radioactive Waste Management Installation

    International Nuclear Information System (INIS)

    Zainus-Salimin

    2000-01-01

    Identification of heat transfer resistance of scale deposit from fixedhardness of liquid waste in the form of CaSO 4 and MgSO 4 ratio 2:1 has beendone on the evaporation system of Serpong Nuclear Facilities fordetermination of the quality of heat transfer obstruction from heating sourceto solution. Evaporation simulation of solution containing hardness withconcentration 0.5; 1; 2; and 2.5% mass were done on the stainless steelcontainer of 1 / volume with electrical heater in which a stainless-steeltube is put down on the base container. After 24, 168, 336, 504 and 672 hoursevaporation process it is obtained the thickness of scale deposit on thesurface of tube for determining the fouling factor. Heat transfer resistanceof scale deposit from 672 hours evaporation of solution 2.5% concentrationhampered heat transfer, the value of fouling factor be superior to limitsvalue of 0.000515 hours.m 2 . o C/kcal.The fouling factor from the evaporationof solution of 0.5; 1; and 2% concentration during 672 hours be inferior tolimits value. (author)

  6. Pengaruh Pretreatment Secara Alkalisasi-Resistive Heating terhadap Kandungan Lignoselulosa Jerami Padi

    Directory of Open Access Journals (Sweden)

    Dewi Maya Maharani

    2017-09-01

    Full Text Available Cellulose is a potential biomass that is used for bioethanol production and commonly present in agricultural residues like rice straw. Cellulose is an important material to produce glucose and bioethanol, but it is covered by lignin and hemicellulose bonds to form a lignocellulose.  Bioethanol production using basic material containing cellulose requires special attention in the process of pretreatment for lignin degradation process and increase the accessible surface and decrystallize cellulose. The aim of this research was to apply alkalization and resistive heating combine method for rice straw pretreatment process before further being converted into bioethanol and to determine the effects of heating temperature and NaOH concentration on the content of  lignin, cellulose, and hemicellulose. The reactor had been designed for resistive heating process. Rice straw that was resized into 100 mesh has dissolved with 0.03 M, 0.05 M, and 0.07 M NaOH and heated with resistive heating temperature of 75 oC, 85 oC, and 99 oC. Cellulose is a raw material that will be further converted into glucose. So that, the selected optimum conditions of this study were  pretreatment with the highest increase of cellulose content level until 8.88% and resulted decreasing levels of lignin (1.39% and hemicellulose (4.33% by temperature  75 oC and 0.07 M NaOH concentration. Resistive heating that combine with alkalization can be used for rice straw pretreatment process that reduce lignin and hemicellulose content as well as increasing cellulose content.   ABSTRAK Selulosa merupakan biomassa yang potensial digunakan untuk produksi bioetanol dan banyak ditemukan di residu pertanian seperti jerami padi. Selulosa merupakan material penting yang dapat dikonversi menjadi glukosa kemudian dikonversi menjadi bioetanol, namun selulosa pada alam dilapisi oleh ikatan lignin dan hemiselulosa menjadi lignoselulosa. Pembuatan bioetanol berbasis selulosa membutuhkan proses

  7. An Interactive Energy System with Grid, Heating and Transportation Systems

    DEFF Research Database (Denmark)

    Diaz de Cerio Mendaza, Iker

    , flexibility definition and quantification, stochastic impact assessment of LV networks and control of the demand response in LV networks. In a first stage, different residential and non-residential loads are modelled with system analysis purposes. The active loads considered can be categorized as...... of this research work the control of the demand response in LV networks is tackled. The hierarchical structure presented aims to control the operation of heat pumps and plug-in electric vehicles to satisfy technical and commercial aspects of LV grids. This strategy allows system operators to perform their energy......The environmental consciousness and the fact of achieving greater energy independency have led many countries to apply important changes in their energy systems. The intensive renewable energy growth of the last decades represents the most notorious example at this moment. However, this is not only...

  8. Solar hot water space heating system. Technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Van Dam, T

    1979-08-13

    A retrofit solar heating system was installed on Madison Hall at Jordan College, Cedar Springs, Michigan. The system provides heating and domestic water preheating for a campus dormitory. Freeze protection is provided by a draindown system. The building and solar system, construction progress, and design changes are described. Included in appendices are: condensate trap design, structural analysis, pictures of installation, operating instructions, maintenance instructions, and as-built drawings. (MHR)

  9. Shallow heat injection and storage experiment monitored with electrical resistivity tomography and simulated with heat transport model

    OpenAIRE

    Hermans, Thomas; Daoudi, Moubarak; Vandenbohede, Alexander; Lebbe, Luc; Nguyen, Frédéric

    2011-01-01

    Groundwater resources are increasingly used around the world as geothermal systems. Understanding physical processes and quantification of parameters determining heat transport in porous media is therefore important. To monitor the geothermal behavior of groundwater systems and to estimate the governing parameters, we rely mainly on borehole observations of the temperature field at a few locations (temperature logs or thermal response test). In analogy to research in hydrogeophysics, geophysi...

  10. Thermal resistance of naturally occurring airborne bacterial spores. [Viking spacecraft dry heat decontamination simulation

    Science.gov (United States)

    Puleo, J. R.; Bergstrom, S. L.; Peeler, J. T.; Oxborrow, G. S.

    1978-01-01

    Simulation of a heat process used in the terminal dry-heat decontamination of the Viking spacecraft is reported. Naturally occurring airborne bacterial spores were collected on Teflon ribbons in selected spacecraft assembly areas and subsequently subjected to dry heat. Thermal inactivation experiments were conducted at 105, 111.7, 120, 125, 130, and 135 C with a moisture level of 1.2 mg of water per liter. Heat survivors were recovered at temperatures of 135 C when a 30-h heating cycle was employed. Survivors were recovered from all cycles studied and randomly selected for identification. The naturally occurring spore population was reduced an average of 2.2 to 4.4 log cycles from 105 to 135 C. Heating cycles of 5 and 15 h at temperature were compared with the standard 30-h cycle at 111.7, 120, and 125 C. No significant differences in inactivation (alpha = 0.05) were observed between 111.7 and 120 C. The 30-h cycle differs from the 5- and 15-h cycles at 125 C. Thus, the heating cycle can be reduced if a small fraction (about 0.001 to 0.0001) of very resistant spores can be tolerated.

  11. Simulation of Hybrid Photovoltaic Solar Assisted Loop Heat Pipe/Heat Pump System

    Directory of Open Access Journals (Sweden)

    Nannan Dai

    2017-02-01

    Full Text Available A hybrid photovoltaic solar assisted loop heat pipe/heat pump (PV-SALHP/HP water heater system has been developed and numerically studied. The system is the combination of loop heat pipe (LHP mode and heat pump (HP mode, and the two modes can be run separately or compositely according to the weather conditions. The performances of independent heat pump (HP mode and hybrid loop heat pipe/heat pump (LHP/HP mode were simulated and compared. Simulation results showed that on typical sunny days in spring or autumn, using LHP/HP mode could save 40.6% power consumption than HP mode. In addition, the optimal switchover from LHP mode to HP mode was analyzed in different weather conditions for energy saving and the all-year round operating performances of the system were also simulated. The simulation results showed that hybrid LHP/HP mode should be utilized to save electricity on sunny days from March to November and the system can rely on LHP mode alone without any power consumption in July and August. When solar radiation and ambient temperature are low in winter, HP mode should be used

  12. Theoretical energy and exergy analyses of solar assisted heat pump space heating system

    Directory of Open Access Journals (Sweden)

    Atmaca Ibrahim

    2014-01-01

    Full Text Available Due to use of alternative energy sources and energy efficient operation, heat pumps come into prominence in recent years. Especially in solar-assisted heat pumps, sizing the required system is difficult and arduous task in order to provide optimum working conditions. Therefore, in this study solar assisted indirect expanded heat pump space heating system is simulated and the results of the simulation are compared with available experimental data in the literature in order to present reliability of the model. Solar radiation values in the selected region are estimated with the simulation. The case study is applied and simulation results are given for Antalya, Turkey. Collector type and storage tank capacity effects on the consumed power of the compressor, COP of the heat pump and the overall system are estimated with the simulation, depending on the radiation data, collector surface area and the heating capacity of the space. Exergy analysis is also performed with the simulation and irreversibility, improvement potentials and exergy efficiencies of the heat pump and system components are estimated.

  13. Building integration of concentrating solar systems for heating applications

    International Nuclear Information System (INIS)

    Tsoutsou, Sapfo; Infante Ferreira, Carlos; Krieg, Jan; Ezzahiri, Mohamed

    2014-01-01

    A new solar collection system integrated on the façade of a building is investigated for Dutch climate conditions. The solar collection system includes a solar façade, a receiver tube and 10 Fresnel lenses. The Fresnel lenses Fresnel lenses considered were linear, non-imaging, line – focused with a system tracking the position of the sun that ensures vertical incidence of the direct solar radiation on the lenses. For the heating system a double-effect absorption heat pump, which requires high temperature of the heating fluid, was used, working with water and lithium-bromide as refrigerant and solution respectively. The Fresnel lens system is connected with the absorption heat pump through a thermal energy storage tank which accumulates the heat from the Fresnel lens system to provide it to the high pressure generator of the absorption heat pump. - Highlights: • The integration of Fresnel lenses in solar thermal building façades is investigated. • Using building integrated Fresnel lenses, 43% heating energy can be saved. • Energy savings in Mediterranean countries are significantly larger. • The absorption heat pump could make great contribution to energy savings for Dutch climate conditions

  14. Transient, heat-induced thermal resistance in the small intestine of mouse

    International Nuclear Information System (INIS)

    Hume, S.P.; Marigold, J.C.L.

    1980-01-01

    Heat-induced thermal resistance has been investigated in mouse jejunum by assaying crypt survival 24 h after treatment. Hyperthermia was achieved by immersing an exteriorized loop of intestine in a bath of Krebs-Ringer solution. Two approaches have been used. In the first, thermal survival curves were obtained following single hyperthermal treatments at temperatures in the range 42 to 44 0 C. Transient thermal resistance, inducted by a plateau in the crypt survival curve, developed during heating at temperatures around 42.5 0 C after 60 to 80 min. In the second series of experiments, a priming heat treatment (40.0, 41.0, 41.5, or 42.0 0 C for 60 min) was followed at varying intervals by a test treatment at 43.0 0 C. A transient resistance to the second treatment was induced, the extent and time of development being dependent upon the priming treatment. Crypt survival curves for thermally resistant intestine showed an increase in thermal D 0 and a decrease in n compared with curves from previously unheated intestine

  15. Evaluation of the contact angle and frost resistance of hydrophobised heat-insulating mortars with polystyrene

    Science.gov (United States)

    Barnat-Hunek, Danuta; Łagód, Grzegorz; Klimek, Beata

    2017-07-01

    The aim of the research presented in the paper was to evaluate the feasibility of using hydrophobic preparation based on organosilicon compounds for surface protection on the heat-insulating mortars modified with polystyrene. The work discusses issues related to wettability, absorptivity and frost resistance of the surface layer of mortars. The experimental part pertains to the physical and mechanical properties of polystyrene-modified mortars and the influence of hydrophobic preparation on the contact angle and frost resistance. The frost resistance of mortars was examined following 25 cycles of freezing and thawing. The contact angle of light mortars (θw) was determined before and after the tests of frost resistance, in the function of time using a single measurement liquid. This provided a basis for calculating the surface free energy with Neumann method, characterizing the wettability and adhesion of mortars under normal conditions and with damages resulting from frost weathering. The structure of mortars and the adhesion of lightweight aggregate to cement paste were presented by means of scanning electron microscopy. The studies enabled to determine the hydrophobisation efficiency of heat-insulating mortars with polystyrene. The obtained results confirmed the possibility of producing heat-insulating mortars modified with polystyrene along with proper surface protection against moisture and frost.

  16. User resistance to information system implementations

    DEFF Research Database (Denmark)

    Campbell, Robert H.; Grimshaw, Mark

    2016-01-01

    Users often resist information system implementations and it has been established that this can cause an implementation to fail. In this paper, the user attitudes that can cause resistance are examined using an established attitude change theory from social and cognitive psychology: the Elaboration......-ranging study are presented that, in addition to supporting this argument, identifies and classifies 19 new heuristics and peripheral influences (in addition to the nine already known) that commonly, and adversely, affect user attitudes and responses to new information system implementations....

  17. Hybrid Ventilation with Innovative Heat Recovery—A System Analysis

    Directory of Open Access Journals (Sweden)

    Bengt Hellström

    2013-02-01

    Full Text Available One of the most important factors when low energy houses are built is to have good heat recovery on the ventilation system. However, standard ventilation units use a considerable amount of electricity. This article discusses the consequences on a system level of using hybrid ventilation with heat recovery. The simulation program TRNSYS was used in order to investigate a ventilation system with heat recovery. The system also includes a ground source storage and waste water heat recovery system. The result of the analysis shows that the annual energy gain from ground source storage is limited. However, this is partly a consequence of the fact that the well functioning hybrid ventilation system leaves little room for improvements. The analysis shows that the hybrid ventilation system has potential to be an attractive solution for low energy buildings with a very low need for electrical energy.

  18. Resistive wall heating due to image current on the beam chamber for a superconducting undulator.

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S. H. (Accelerator Systems Division (APS))

    2012-03-27

    The image-current heating on the resistive beam chamber of a superconducting undulator (SCU) was calculated based on the normal and anomalous skin effects. Using the bulk resistivity of copper for the beam chamber, the heat loads were calculated for the residual resistivity ratios (RRRs) of unity at room temperature to 100 K at a cryogenic temperature as the reference. Then, using the resistivity of the specific aluminum alloy 6053-T5, which will be used for the SCU beam chamber, the heat loads were calculated. An electron beam stored in a storage ring induces an image current on the inner conducting wall, mainly within a skin depth, of the beam chamber. The image current, with opposite charge to the electron beam, travels along the chamber wall in the same direction as the electron beam. The average current in the storage ring consists of a number of bunches. When the pattern of the bunched beam is repeated according to the rf frequency, the beam current may be expressed in terms of a Fourier series. The time structure of the image current is assumed to be the same as that of the beam current. For a given resistivity of the chamber inner wall, the application ofthe normal or anomalous skin effect will depend on the harmonic numbers of the Fourier series of the beam current and the temperature of the chamber. For a round beam chamber with a ratius r, much larger than the beam size, one can assume that the image current density as well as the density square, may be uniform around the perimeter 2{pi}r. For the SCU beam chamber, which has a relatively narrow vertical gap compared to the width, the effective perimeter was estimated since the heat load should be proportional to the inverse of the perimeter.

  19. Proliferation resistance assessment of nuclear systems

    International Nuclear Information System (INIS)

    1978-09-01

    The first part of the present paper describes the basic assessment procedure that is adopted in the analysis of the three generic nuclear systems. Once-through, fast breeder, and thermal recycle systems are then treated in Sections II, III, and IV, respectively. In each of these sections, a reference system is examined, possible technical and institutional improvements are considered, and alternative system types are indicated. Section V then discusses the relative proliferation resistance of the three generic systems. Although this paper emphasizes the analysis and comparison of individual fuel cycle alternatives, Section V indicates briefly how these analyses then have to be considered in a broader context where systems coexist

  20. Commercial high efficiency dehumidification systems using heat pipes

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-01

    An improved heat pipe design using separately connected two-section one-way flow heat pipes with internal microgrooves instead of wicks is described. This design is now commercially available for use to increase the dehumidification capacity of air conditioning systems. The design also includes a method of introducing fresh air into buildings while recovering heat and controlling the humidity of the incoming air. Included are applications and case studies, load calculations and technical data, and installation, operation, and maintenance information.

  1. Monitoring of high temperature area by resistivity tomography during in-situ heating test in sedimentary soft rocks

    International Nuclear Information System (INIS)

    Kubota, Kenji; Suzuki, Koichi; Ikenoya, Takafumi; Takakura, Nozomu; Tani, Kazuo

    2009-01-01

    One of the major issues in disposal of nuclear waste is that the long term behaviors of sedimentary soft rocks can be affected by various environmental factors such as temperature, mechanical conditions or hydraulic conditions. Therefore, it is necessary to develop a method for evaluating the long term stability of caverns in sedimentary soft rocks as subjected to changes of environment. We have conducted in-situ heating test to evaluate the influence of high temperature to the surrounding rock mass at a depth of 50 m. The well with a diameter of 30 cm and 60 cm of height, was drilled and filled with groundwater. The heater was installed in the well for heating the surrounding rock mass. During the heating, temperature and deformation around the well were measured. To evaluate the influence of heating on sedimentary soft rocks, it is important to monitor the extent of heated area. Resistivity monitoring is thought to be effective to map the extent of the high temperature area. So we have conducted resistivity tomography during the heating test. The results demonstrated that the resistivity of the rock mass around the heating well decreased and this area was gradually expanded from the heated area during the heating. The decreasing rate of resistivity on temperature is correlated to that of laboratory experimental result and existing empirical formula between aqueous solution resistivity and temperature. Resistivity is changed by many other factors, but it is expected that resistivity change by other factors is very few in this test. This suggests that high temperature area is detected and spatial distribution of temperature can be mapped by resistivity tomography. So resistivity tomography is expected to be one of the promising methods to monitor the area heated by nuclear waste. (author)

  2. Erythrocyte deformability and segmental pulmonary vascular resistance: osmolarity and heat treatment.

    Science.gov (United States)

    Hakim, T S

    1988-10-01

    The site and nature of change in resistance to blood flow in canine left lung lobe preparation after changes in blood viscosity were assessed by using the arterial and venous occlusion (AVO) technique and the vascular pressure-flow relationship. Blood viscosity was changed by erythrocyte (RBC) shrinkage and swelling with hypertonic and hypotonic NaCl solutions and by RBC membrane rigidification with heat treatment (49 degrees C for 1 h). The results show that although all three methods of changing blood viscosity increased the pulmonary vascular resistance (PVR) by 15-50%, the site and nature of the change in PVR were different in each case. The AVO data showed that the increase in PVR with heat treatment of RBC's was due entirely (100%) to increased resistance of the middle microvascular segment, whereas deviation from normal osmolarity potentiated the resistance in arterial, middle, and venous segments. By examining the effect of osmolarity in plasma-perfused lobes, it was possible to separate the increase in PVR due to changes in RBC deformability from those due to other factors. The increase in arterial and venous resistances with hypertonic solution was attributed in part (approximately 50%) to factors other than RBC's; however, the increase in middle resistance was entirely due to RBC crenation. The increase in arterial and venous resistances with hypotonic solutions was small and was apparently caused by factors other than RBC swelling, whereas the increase in middle resistance was partially (approximately 50%) due to RBC swelling and partially to other factors (e.g., endothelial cell hydration).(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Thermochemical heat storage - system design issues

    NARCIS (Netherlands)

    Jong, A.J. de; Trausel, F.; Finck, C.J.; Vliet, L.D. van; Cuypers, R.

    2014-01-01

    Thermochemical materials (TCMs) are a promising solution for seasonal heat storage, providing the possibility to store excess solar energy from the warm season for later use during the cold season, and with that all year long sustainable energy. With our fixed bed, vacuum reactors using zeolite as

  4. Optimal use of antibiotic resistance surveillance systems.

    Science.gov (United States)

    Critchley, I A; Karlowsky, J A

    2004-06-01

    Increasing concern about the emergence of resistance in clinically important pathogens has led to the establishment of a number of surveillance programmes to monitor the true extent of resistance at the local, regional and national levels. Although some programmes have been operating for several years, their true usefulness is only now being realised. This review describes some of the major surveillance initiatives and the way in which the data have been used in a number of different settings. In the hospital, surveillance data have been used to monitor local antibiograms and determine infection control strategies and antibiotic usage policies. In the community, surveillance data have been used to monitor public health threats, such as infectious disease outbreaks involving resistant pathogens and the effects of bioterrorism countermeasures, by following the effects of prophylactic use of different antibiotics on resistance. Initially, the pharmaceutical industry sponsored surveillance programmes to monitor the susceptibility of clinical isolates to marketed products. However, in the era of burgeoning resistance, many developers of antimicrobial agents find surveillance data useful for defining new drug discovery and development strategies, in that they assist with the identification of new medical needs, allow modelling of future resistance trends, and identify high-profile isolates for screening the activity of new agents. Many companies now conduct pre-launch surveillance of new products to benchmark activity so that changes in resistance can be monitored following clinical use. Surveillance data also represent an integral component of regulatory submissions for new agents and, together with clinical trial data, are used to determine breakpoints. It is clear that antibiotic resistance surveillance systems will continue to provide valuable data to health care providers, university researchers, pharmaceutical companies, and government and regulatory agencies.

  5. Solar Heating System for Recreation Building at Scattergood School.

    Science.gov (United States)

    Scattergood School, West Branch, IA.

    This report describes the solar heating of two adjoining buildings, a gymnasium and a locker room, at a coeducational boarding school. Federal assistance was obtained from the Energy Research and Development Administration (ERDA) as part of the Solar Heating and Cooling Demonstration Program. The system uses a 2,500-square-foot array of…

  6. On-line corrosion monitoring in geothermal district heating systems

    DEFF Research Database (Denmark)

    Richter, S.; Hilbert, Lisbeth Rischel; Thorarinsdottir, R.I.

    2006-01-01

    General corrosion rates in the geothermal district heating systems in Iceland are generally low, of the magnitude 1 lm/y. The reason is high pH (9.5), low-conductivity (200 lm/y) and negligible dissolved oxygen. The geothermal hot water is either used directly from source or to heat up cold ground...

  7. Optimal design of solar water heating systems | Alemu | Zede Journal

    African Journals Online (AJOL)

    The pe1formance of the preliminary design is predicted by using either/chart method or by translate it simulation of solar heating system. Often, optimization is done off-line after correlating the annual contribution of solar energy to the heating load and collector area using simulation resu!ts by analytical methods. In this work ...

  8. Smart energy systems and 4th generation district heating

    DEFF Research Database (Denmark)

    Lund, Henrik; Duic, Neven; Østergaard, Poul Alberg

    2016-01-01

    This editorial gives an introduction to the important relationship between Smart Energy Systems and 4th Generation District Heating and presents a number of selected papers from the 1st International Conference on the topic. All of the papers elaborate on or otherwise contribute to the theoretical...... for the active inclusion of the heating and cooling sectors. The concept of 4th Generation District Heating emphasizes that district heating and cooling are both important elements but also technologies that have to be developed further into a 4th generation version to be able to fulfil their roles in future...

  9. Optimization-based design of waste heat recovery systems

    DEFF Research Database (Denmark)

    Cignitti, Stefano

    of performance and sustainability. The fluid was novel and generated through the framework. In the second case study, waste heat recovery from a milk powder production spray dryer was addressed. A heat pump was designed with a mixed working fluid for the optimal heat recovery and transfer for the low-grade waste...... heat from effluent spray dryer air. 25% isobutene and 75% 1,3-difluoropropane and a process with a coefficient of performance of 3.22 was designed. The design provided new binary mixture and optimized cycle process that was an improvement compared to conventional systems. Furthermore, the fluids were...

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

    International Nuclear Information System (INIS)

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

    2017-01-01

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

  11. Dynamic performance of a novel solar photovoltaic/loop-heat-pipe heat pump system

    International Nuclear Information System (INIS)

    Zhang, Xingxing; Zhao, Xudong; Shen, Jingchun; Xu, Jihuan; Yu, Xiaotong

    2014-01-01

    Highlights: • A transient model was developed to predict dynamic performance of new PV/LHP system. • The model accuracy was validated by experiment giving less than 9% in error. • The new system had basic and advanced performance coefficients of 5.51 and 8.71. • The new system had a COP 1.5–4 times that for conventional heat pump systems. • The new system had higher exergetic efficiency than PV and solar collector systems. - Abstract: Objective of the paper is to present an investigation into the dynamic performance of a novel solar photovoltaic/loop-heat-pipe (PV/LHP) heat pump system for potential use in space heating or hot water generation. The methods used include theoretical computer simulation, experimental verification, analysis and comparison. The fundamental equations governing the transient processes of solar transmission, heat transfer, fluid flow and photovoltaic (PV) power generation were appropriately integrated to address the energy balances occurring in different parts of the system, e.g., glazing cover, PV cells, fin sheet, loop heat pipe, heat pump cycle and water tank. A dedicated computer model was developed to resolve the above grouping equations and consequently predict the system’s dynamic performance. An experimental rig was constructed and operated under the real weather conditions for over one week in Shanghai to evaluate the system living performance, which was undertaken by measurement of various operational parameters, e.g., solar radiation, photovoltaic power generation, temperatures and heat pump compressor consumption. On the basis of the first- (energetic) and second- (exergetic) thermodynamic laws, an overall evaluation approach was proposed and applied to conduct both quantitative and qualitative analysis of the PV/LHP module’s efficiency, which involved use of the basic thermal performance coefficient (COP th ) and the advanced performance coefficient (COP PV/T ) of such a system. Moreover, a simple comparison

  12. Horizontal Heat Exchanger Design and Analysis for Passive Heat Removal Systems

    Energy Technology Data Exchange (ETDEWEB)

    Vierow, Karen

    2005-08-29

    This report describes a three-year project to investigate the major factors of horizontal heat exchanger performance in passive containment heat removal from a light water reactor following a design basis accident LOCA (Loss of Coolant Accident). The heat exchanger studied in this work may be used in advanced and innovative reactors, in which passive heat removal systems are adopted to improve safety and reliability The application of horizontal tube-bundle condensers to passive containment heat removal is new. In order to show the feasibility of horizontal heat exchangers for passive containment cooling, the following aspects were investigated: 1. the condensation heat transfer characteristics when the incoming fluid contains noncondensable gases 2. the effectiveness of condensate draining in the horizontal orientation 3. the conditions that may lead to unstable condenser operation or highly degraded performance 4. multi-tube behavior with the associated secondary-side effects This project consisted of two experimental investigations and analytical model development for incorporation into industry safety codes such as TRAC and RELAP. A physical understanding of the flow and heat transfer phenomena was obtained and reflected in the analysis models. Two gradute students (one funded by the program) and seven undergraduate students obtained research experience as a part of this program.

  13. Hyperbolic heat conduction, effective temperature, and third law for nonequilibrium systems with heat flux

    Science.gov (United States)

    Sobolev, S. L.

    2018-02-01

    Some analogies between different nonequilibrium heat conduction models, particularly random walk, the discrete variable model, and the Boltzmann transport equation with the single relaxation time approximation, have been discussed. We show that, under an assumption of a finite value of the heat carrier velocity, these models lead to the hyperbolic heat conduction equation and the modified Fourier law with relaxation term. Corresponding effective temperature and entropy have been introduced and analyzed. It has been demonstrated that the effective temperature, defined as a geometric mean of the kinetic temperatures of the heat carriers moving in opposite directions, acts as a criterion for thermalization and is a nonlinear function of the kinetic temperature and heat flux. It is shown that, under highly nonequilibrium conditions when the heat flux tends to its maximum possible value, the effective temperature, heat capacity, and local entropy go to zero even at a nonzero equilibrium temperature. This provides a possible generalization of the third law to nonequilibrium situations. Analogies and differences between the proposed effective temperature and some other definitions of a temperature in nonequilibrium state, particularly for active systems, disordered semiconductors under electric field, and adiabatic gas flow, have been shown and discussed. Illustrative examples of the behavior of the effective temperature and entropy during nonequilibrium heat conduction in a monatomic gas and a strong shockwave have been analyzed.

  14. Azole-Resistant Central Nervous System Aspergillosis

    NARCIS (Netherlands)

    van der Linden, Jan W. M.; Jansen, Rogier R.; Bresters, Dorine; Visser, Caroline E.; Geerlings, Suzanne E.; Kuijper, Ed J.; Melchers, Willem J. G.; Verweij, Paul E.

    2009-01-01

    Three patients with central nervous system aspergillosis due to azole-resistant Aspergillus fumigatus (associated with a leucine substitution for histidine at codon 98 [L98H] and a 34-base pair repeat in tandem in the promoter region) are described. The patients were treated with combination therapy

  15. Azole-resistant central nervous system aspergillosis.

    NARCIS (Netherlands)

    Linden, J.W.M. van der; Jansen, R.R.; Bresters, D.; Visser, C.E.; Geerlings, S.E.; Kuijper, E.J.; Melchers, W.J.G.; Verweij, P.E.

    2009-01-01

    Three patients with central nervous system aspergillosis due to azole-resistant Aspergillus fumigatus (associated with a leucine substitution for histidine at codon 98 [L98H] and a 34-base pair repeat in tandem in the promoter region) are described. The patients were treated with combination therapy

  16. Energy source completion for geothermal district heating systems

    International Nuclear Information System (INIS)

    Popovski, Kiril

    2000-01-01

    Geothermal district heating systems differs from the others mainly in the part of energy source completion and its connection to the heat distribution systems rather known problem. Even rather known problematic in the countries where geothermal energy is in wide application, new appearances of mistakes are always present due to the fact that necessary literature is difficult to be found. Essentials of the geothermal well completion and connection of geothermal source to the district heating distribution system are summarized in the paper and several examples of geothermal projects in flow are presented. (Author)

  17. Effects of erodant particle shape and various heat treatments on erosion resistance of plain carbon steel

    Science.gov (United States)

    Salik, J.; Buckley, D. H.

    1981-01-01

    Erosion tests were conducted on 1045 steel samples which had been subjected to different heat treatments. The weight of material removed upon erosion with glass beads and crushed glass was measured. The data show that there is no correlation between hardness and erosion resistance. The erosion rate was strongly dependent on the shape of erodant particles, being an order of magnitude higher for erosion with crushed glass than with glass beads. Heat treatment had a profound effect on the erosion resistance when the erodant particles were glass beads but little or no effect when the particles were crushed glass. It is thus concluded that different mechanisms of material removal are involved with these two erodants. This conclusion is supported by the surface morphology of annealed 1045 steel samples which had been eroded by these two types of erodant particles. SEM micrographs of the eroded surfaces show that for erosion with glass beads it is deformation induced fracture of surface layers.

  18. Green certificate system for heating - principal and practical challenges

    International Nuclear Information System (INIS)

    Eldegard, Tom

    2002-01-01

    A certificate system with an obligation to buying is a very relevant instrument in energy policy in order to stimulate the implementation of new renewable energy sources. This solution is widely supported; it is being institutionalized in many countries, especially in Europe and in the electricity sector, and the heating sector is soon to follow. This report discusses the broad lines of a possible green certificate system for the heating sector in Norway and concludes that it is might well be linked with a similar system for the electricity sector. For Norway, an isolated certificate system for the electricity sector would not be cost-effective. This is because this system would emphasize relatively expensive renewable electric energy rather than utilizing the large potential for replacing the electric heating of buildings with much cheaper renewable heat

  19. Benefits of Integrating Geographically Distributed District Heating Systems

    DEFF Research Database (Denmark)

    Dominkovic, Dominik Franjo; Bačeković, I.; Sveinbjörnsson, Dadi Þorsteinn

    2016-01-01

    was reduced by 1.76 %. For the year 2029, in which intermittent renewable energy sources are dominating the energy generation, total socio-economic costs were reduced by 5.9 %, CO2 emissions by 7.1 % and primary energy supply by 8.4 % after the adjacent district heating systems were connected. Hence......Although liberalization of the electricity day-ahead markets has gained pace throughout the Europe, district heating markets are often dominated by lack of competition between suppliers, which curbs the potential of having cheaper systems in terms of socio-economic costs, and technically better...... system in terms of CO2 emissions. In order to assess the financial and technical outcome of connecting five adjacent district heating systems, a linear continuous optimization model that minimizes total socio-economic costs was developed. Geographical distribution of different district heating systems...

  20. Molten Chloride Salts for Heat Transfer in Nuclear Systems

    Science.gov (United States)

    Ambrosek, James Wallace

    2011-12-01

    A forced convection loop was designed and constructed to examine the thermal-hydraulic performance of molten KCl-MgCl2 (68-32 at %) salt for use in nuclear co-generation facilities. As part of this research, methods for prediction of the thermo-physical properties of salt mixtures for selection of the coolant salt were studied. In addition, corrosion studies of 10 different alloys were exposed to the KCl-MgCl2 to determine a suitable construction material for the loop. Using experimental data found in literature for unary and binary salt systems, models were found, or developed to extrapolate the available experimental data to unstudied salt systems. These property models were then used to investigate the thermo-physical properties of the LINO3-NaNO3-KNO 3-Ca(NO3), system used in solar energy applications. Using these models, the density, viscosity, adiabatic compressibility, thermal conductivity, heat capacity, and melting temperatures of higher order systems can be approximated. These models may be applied to other molten salt systems. Coupons of 10 different alloys were exposed to the chloride salt for 100 hours at 850°C was undertaken to help determine with which alloy to construct the loop. Of the alloys exposed, Haynes 230 had the least amount of weight loss per area. Nickel and Hastelloy N performed best based on maximum depth of attack. Inconel 625 and 718 had a nearly uniform depletion of Cr from the surface of the sample. All other alloys tested had depletion of Cr along the grain boundaries. The Nb in Inconel 625 and 718 changed the way the Cr is depleted in these alloys. Grain-boundary engineering (GBE) of Incoloy 800H improved the corrosion resistance (weight loss and maximum depth of attack) by nearly 50% as compared to the as-received Incoloy 800H sample. A high temperature pump, thermal flow meter, and pressure differential device was designed, constructed and tested for use in the loop, The heat transfer of the molten chloride salt was found to

  1. Polyphasic taxonomy of the heat resistant ascomycete genus Byssochlamys and its Paecilomyces anamorphs

    DEFF Research Database (Denmark)

    Samson, R.A.; Houbraken, J.; Varga, J.

    2009-01-01

    Byssochlamys and related Paecilomyces strains are often heat resistant and may produce mycotoxins in contaminated pasteurised foodstuffs. A comparative study of all Byssochlamys species was carried out using a polyphasic approach to find characters that differentiate species and to establish...... accurate data on potential mycotoxin production by each species. Phylogenetic analysis of the ITS region, parts of the P-tubulin and calmodulin genes, macro- and micromorphological examinations and analysis of extrolite profiles were applied. Phylogenetic analyses revealed that the genus Byssochlamys...

  2. IEA Annex 26: Advanced Supermarket Refrigeration/Heat Recovery Systems

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, VAN

    2003-05-19

    With increased concern about the impact of refrigerant leakage on global warming, a number of new supermarket refrigeration system configurations requiring significantly less refrigerant charge are being considered. In order to help promote the development of advanced systems and expand the knowledge base for energy-efficient supermarket technology, the International Energy Agency (IEA) established IEA Annex 26 (Advanced Supermarket Refrigeration/Heat Recovery Systems) under the ''IEA Implementing Agreement on Heat Pumping Technologies''. Annex 26 focuses on demonstrating and documenting the energy saving and environmental benefits of advanced systems design for food refrigeration and space heating and cooling for supermarkets. Advanced in this context means systems that use less energy, require less refrigerant and produce lower refrigerant emissions. Stated another way, the goal is to identify supermarket refrigeration and HVAC technology options that reduce the total equivalent warming impact (TEWI) of supermarkets by reducing both system energy use (increasing efficiency) and reducing total refrigerant charge. The Annex has five participating countries: Canada, Denmark, Sweden, the United Kingdom, and the United States. The working program of the Annex has involved analytical and experimental investigation of several candidate system design approaches to determine their potential to reduce refrigerant usage and energy consumption. Advanced refrigeration system types investigated include the following: distributed compressor systems--small parallel compressor racks are located in close proximity to the food display cases they serve thus significantly shortening the connecting refrigerant line lengths; secondary loop systems--one or more central chillers are used to refrigerate a secondary coolant (e.g. brine, ice slurry, or CO2) that is pumped to the food display cases on the sales floor; self-contained display cases--each food display case

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

    DEFF Research Database (Denmark)

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

    2017-01-01

    With the present trend towards Smart Grids and Smart Energy Systems it is important to look for the opportunities for integrated development between different energy sectors, such as electricity, heating, gas and transportation. This paper investigates the problem of optimal placement of a heat...... with the help of mathematical optimization that minimizes investments of both electric and heating utilities, achieving the reduction of the total investment. The optimization is performed in Matlab using built-in Genetic Algorithm function and Matpower software package for calculating power flow equations....

  4. National district-heating program: generic city district-heating and cooling system from cogeneration retrofit

    Energy Technology Data Exchange (ETDEWEB)

    Davis, H.; Grammel, S.; Kuzanek, J.; Levine, E.

    1981-02-01

    A study, designed to aid in evaluating the feasibility of a district heating and cooling system that uses heat supplied by existing electric generating plants retrofitted for cogeneration, is presented. Based on thermal demands of a metropolitan area, the District Heating and Cooling System (DHCS) model estimates the cost of the retrofit. Environmental impact and the potential for scarce-fuel savings also are assessed by this model. The computer program used is the District Heating Strategy Model (DHSM). Section 2 identifies metropolitan demand sectors and describes the data acquisition method. Section 3 defines thermal energy supply sources and shows how each is located. Program output is summarized in terms of financial data, electrical and thermal loads, and a ranking of existing power plants. Section 4 assesses air pollutant emissions and DHCS fuel-use requirements. Finally, Sec. 5 considers the economics of the DHCS and its costs vs benefits.

  5. Proliferation resistance assessment of nuclear systems

    International Nuclear Information System (INIS)

    1978-09-01

    The paper focuses on examining the degree to which nuclear systems could be used to acquire nuclear weapons material. It establishes a framework for proliferation resistance assessment and illustrates its applicability through an analysis of reference systems for once-through cycles, breeder cycles and thermal recycle. On a more tentative basis, the approach is applied to various alternative technical and institutional measures. This paper was also submitted to Working Groups 5 and 8

  6. Induced systemic resistance by fluorescent Pseudomonas spp.

    OpenAIRE

    Bakker, P.A.H.M.; Pieterse, C.M.J.; Loon, L.C. van

    2007-01-01

    Fluorescent Pseudomonas spp. have been studied for decades for their plant growth-promoting effects through effective suppression of soilborne plant diseases. The modes of action that play a role in disease suppression by these bacteria include siderophore-mediated competition for iron, antibiosis, production of lytic enzymes, and induced systemic resistance (ISR). The involvement of ISR is typically studied in systems in which the Pseudomonas bacteria and the pathogen are inoculated and rema...

  7. Induced Systemic Resistance by Beneficial Microbes

    OpenAIRE

    Corn\\xe M.J. Pieterse; Christos Zamioudis; Roeland L. Berendsen; David M. Weller; Saskia C.M. Van Wees; Peter A.H.M. Bakker

    2014-01-01

    Beneficial microbes in the microbiome of plant roots improve plant health. Induced systemic resistance (ISR) emerged as an important mechanism by which selected plant growth–promoting bacteria and fungi in the rhizosphere prime the whole plant body for enhanced defense against a broad range of pathogens and insect herbivores. A wide variety of root-associated mutualists, including Pseudomonas, Bacillus, Trichoderma, and mycorrhiza species sensitize the plant immune system for enhanced defense...

  8. The influence of sodium chlorides fog on corrosion resistance of heat exchangers used in automotive

    Directory of Open Access Journals (Sweden)

    Peta Katarzyna

    2017-01-01

    Full Text Available In the work, the most important factors which influence on the exploitative durability of heat exchangers are classified. Particular attention was paid to the compounds of sodium chloride used in the winter season for road maintenance. In order to determine their impact on automotive heat exchanger corrosion resistance, a test of heaters in a salt chamber which imitates the conditions of their work was realized. It also allows to verify the durability of these products. To evaluate the corrosion changes, observation with the use of light microscopy and scanning microscopy SEM were made supplemented with microanalysis of chemical composition by EDS spectroscopy method. Critical areas in the heat exchangers which are mostly exposed to damage including the formation of local corrosion pits were located and analyzed.

  9. Heat enhancement of radiation resistivity of evaporated CsI, KI and KBr photocathodes

    CERN Document Server

    Tremsin, A S

    2000-01-01

    The photoemissive stability of as-deposited and heat-treated CsI, KI and KBr evaporated thin films under UV radiation is examined in this paper. After the deposition, some photocathodes were annealed for several hours at 90 deg. C in vacuum and their performance was then compared to the performance of non-heated samples. We observed that the post-evaporation thermal treatment not only increases the photoyield of CsI and KI photocathodes in the spectral range of 115-190 nm, but also reduces CsI, KI and KBr photocurrent degradation that occurs after UV irradiation. KBr evaporated layers appeared to be more radiation-resistant than CsI and KI layers. Post-deposition heat treatment did not result in any significant variation of KBr UV sensitivity.

  10. Role of Ca ions in the induction of heat-resistance of wheat coleoptiles by brassinosteroids

    Directory of Open Access Journals (Sweden)

    Yu. E. Kolupaev

    2015-02-01

    Full Text Available The involvement of Ca2+ into the signal transduction of exogenous brassinosteroids (BS (24-epibrassinolide – 24-EBL and 24-epicastasterone – 24 ECS causing the increase of heat resistance of the cells of wheat (Triticum aestivum L. coleoptiles was investigated using calcium chelator EGTA and inhibitor of phosphatidylinositol-specific phospholipase C – neomycin. Twenty-four-hour treatment of coleoptile segments with 10 nM solutions of 24-EBL and 24-ECS led to a transient increase in the generation of superoxide anion radical by cell surface and the subsequent activation of superoxide dismutase and catalase. Pretreatment of coleoptiles with EGTA and neomycin depressed to a considerable extent these effects and leveled the increase in heat resistance of wheat coleoptiles that were caused by BS. Possible mechanisms of involvement of calcium signaling into the formation of reactive oxygen species in plant cells and induction of heat resistance of plant cells by the action of exogenous BS have been discussed.

  11. Significant effect of Ca2+ on improving the heat resistance of lactic acid bacteria.

    Science.gov (United States)

    Huang, Song; Chen, Xiao Dong

    2013-07-01

    The heat resistance of lactic acid bacteria (LAB) has been extensively investigated due to its highly practical significance. Reconstituted skim milk (RSM) has been found to be one of the most effective protectant wall materials for microencapsulating microorganisms during convective drying, such as spray drying. In addition to proteins and carbohydrate, RSM is rich in calcium. It is not clear which component is critical in the RSM protection mechanism. This study investigated the independent effect of calcium. Ca(2+) was added to lactose solution to examine its influence on the heat resistance of Lactobacillus rhamnosus ZY, Lactobacillus casei Zhang, Lactobacillus plantarum P8 and Streptococcus thermophilus ND03. The results showed that certain Ca(2+) concentrations enhanced the heat resistance of the LAB strains to different extents, that is produced higher survival and shorter regrowth lag times of the bacterial cells. In some cases, the improvements were dramatic. More scientifically insightful and more intensive instrumental study of the Ca(2+) behavior around and in the cells should be carried out in the near future. In the meantime, this work may lead to the development of more cost-effective wall materials with Ca(2+) added as a prime factor. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  12. Embedded resistance wire as a heating element for temperature control in microbioreactors

    International Nuclear Information System (INIS)

    Alam, Muhd Nazrul Hisham Zainal; Schäpper, Daniel; Gernaey, Krist V

    2010-01-01

    This paper presents the technical realization of a low-cost heating element consisting of a resistance wire in a microbioreactor, as well as the implementation and performance assessment of an on/off controller for temperature control of the microbioreactor content based on this heating element. The microbioreactor (working volume of 100 µL) is designed to work bubble-free, and is fabricated out of the polymers poly(methylmethacrylate) (PMMA) and poly(dimethylsiloxane) (PDMS). The temperature is measured with a Pt 100 sensor, and the resistance wires are embedded in the polymer such that they either surround the reactor chamber or are placed underneath it. The latter can achieve an even temperature distribution across the reactor chamber and direct heating of the reactor content. We show that an integrated resistance wire coupled to a simple on/off controller results in accurate temperature control of the reactor (±0.1 °C of the set point value) and provides a good disturbance rejection capability (corrective action for a sudden temperature drop of 2.5 °C at an operating temperature of 50 °C takes less than 30 s). Finally, we also demonstrate the workability of the established temperature control in a batch Saccharomyces cerevisiae cultivation in a microbioreactor.

  13. Performance of Space Heating in a Modern Energy System

    DEFF Research Database (Denmark)

    Elmegaard, Brian

    2011-01-01

    In the paper we study the performance of a number of heat supply technologies. The background of the study is the changes in the Danish energy systems over the last three decades which have caused integration of large shares of combined heat and power (CHP), renewable fuels and wind power. These ...... are the technologies with best performance, unless we consider solar heating and biomass from the viewpoints of CO2 emissions and fossil fuel consumption.......In the paper we study the performance of a number of heat supply technologies. The background of the study is the changes in the Danish energy systems over the last three decades which have caused integration of large shares of combined heat and power (CHP), renewable fuels and wind power....... These changes mean that there is a significant integration of electricity and heat supply in the system and that several technologies may be beneficial. In particular, heat pumps are under consideration and are often considered to be renewable energy. We study how to distribute fuel and emissions to the heat...

  14. Surface resistance of superconductors - examples from Nb - O systems

    International Nuclear Information System (INIS)

    Palmer, F.

    1988-01-01

    The observed surface resistance of most superconductors can be written as the sum of two terms. R/sub obs/ = R/sub BCS/ + R/sub res/. This paper is divided into three sections. The first section describes the BCS theory of surface resistance in terms of a simplified two-fluid model. The second section describes several possible causes of residual resistance including normal conducting materials, tunneling across cracks in the surface, and direct generation of phonons by the RF electric field. The last section describes recent experiments having to do with the effects of oxide layers on surface resistance. Layers grown in pure oxygen at room temperature were found to have little or no effect, but if these layers are heated to temperatures near 300 0 C, they can alter both the BCS resistance and the residual resistance. Heated oxide layers also increased the dependence of the residual resistance on ambient magnetic field. 31 references, 13 figures, 3 tables

  15. Passive ventilation systems with heat recovery and night cooling

    DEFF Research Database (Denmark)

    Hviid, Christian Anker; Svendsen, Svend

    2008-01-01

    of Denmark. Through building integration in high performance offices the system is optimized to incorporate multiple functions like heating, cooling and ventilation, thus saving the expenses of separate cooling and heating systems. The simulation results are derived using the state-of-the-art building......In building design the requirements for energy consumption for ventilation, heating and cooling and the requirements for increasingly better indoor climate are two opposing factors. This paper presents the schematic layout and simulation results of an innovative multifunc-tional ventilation concept...... with little energy consumption and with satisfying indoor climate. The concept is based on using passive measures like stack and wind driven ventilation, effective night cooling and low pressure loss heat recovery using two fluid coupled water-to-air heat exchangers developed at the Technical University...

  16. Beam heat load due to geometrical and resistive wall impedance in COLDDIAG

    Science.gov (United States)

    Casalbuoni, S.; Migliorati, M.; Mostacci, A.; Palumbo, L.; Spataro, B.

    2012-11-01

    One of the still open issues for the development of superconductive insertion devices is the understanding of the heat intake from the electron beam. With the aim of measuring the beam heat load to a cold bore and the hope to gain a deeper understanding in the underlying mechanisms, a cold vacuum chamber for diagnostics (COLDDIAG) was built. It is equipped with the following instrumentation: retarding field analyzers to measure the electron flux, temperature sensors to measure the beam heat load, pressure gauges, and mass spectrometers to measure the gas content. Possible beam heat load sources are: synchrotron radiation, wakefield effects due to geometrical and resistive wall impedance and electron/ion bombardment. The flexibility of the engineering design will allow the installation of the cryostat in different synchrotron light sources. COLDDIAG was first installed in the Diamond Light Source (DLS) in 2011. Due to a mechanical failure of the thermal transition of the cold liner, the cryostat had to be removed after one week of operation. After having implemented design changes in the thermal liner transition, COLDDIAG has been reinstalled in the DLS at the end of August 2012. In order to understand the beam heat load mechanism it is important to compare the measured COLDDIAG parameters with theoretical expectations. In this paper we report on the analytical and numerical computation of the COLDDIAG beam heat load due to coupling impedances deriving from unavoidable step transitions, ports used for pumping and diagnostics, surface roughness, and resistive wall. The results might have an important impact on future technological solutions to be applied to cold bore devices.

  17. Ten questions about radiant heating and cooling systems

    DEFF Research Database (Denmark)

    Rhee, Kyu-Nam; Olesen, Bjarne W.; Kim, Kwang Woo

    2017-01-01

    and cooling. On the other hand, the RHC system has limitations such as complicated control of Thermally Activated Building System (TABS), acoustical issues, higher capital cost and cooling load than conventional air systems, and so on. For now, the required mitigation of these limitations and the need......Radiant heating and cooling (RHC) systems are being increasingly applied not only in residential but also in non-residential buildings such as commercial buildings, education facilities, and even large scale buildings such as airport terminals. Furthermore, with the combined ventilation system used...... studies on RHC systems in terms of comfort, heat transfer analysis, energy simulation, control strategy, system configurations and so on. Many studies have demonstrated that the RHC system is a good solution to improve indoor environmental quality while reducing building energy consumption for heating...

  18. Heat Transfer Phenomena in Concentrating Solar Power Systems.

    Energy Technology Data Exchange (ETDEWEB)

    Armijo, Kenneth Miguel; Shinde, Subhash L.

    2016-11-01

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

  19. Convective heat and mass transfer in rotating disk systems

    CERN Document Server

    Shevchuk, Igor V

    2009-01-01

    The book describes results of investigations of a series of convective heat and mass transfer problems in rotating-disk systems. Methodology used included integral methods, self-similar and approximate analytical solutions, as well as CFD.

  20. Combined solar heat and power system with a latent heat storage - system simulations for an economic assessment

    Science.gov (United States)

    Zipf, Verena; Neuhäuser, Anton

    2016-05-01

    Decentralized solar combined heat and power (CHP) systems can be economically feasible, especially when they have a thermal storage. In such systems, heat provided by solar thermal collectors is used to generate electricity and useful heat for e.g. industrial processes. For the supply of energy in times without solar irradiation, a thermal storage can be integrated. In this work, the performance of a solar CHP system using an active latent heat storage with a screw heat exchanger is investigated. Annual yield calculations are conducted in order to calculate annual energy gains and, based on them; economic assumptions are used to calculated economic numbers in order to assess the system performance. The energy savings of a solar system, compared to a system with a fossil fuel supply, are calculated. Then the net present value and the dynamic payback are calculated with these savings, the initial investment costs and the operational costs. By interpretation and comparison of these economic numbers, an optimum system design in terms of solar field size and storage size was determined. It has been shown that the utilization of such systems can be economical in remote areas without gas and grid connection. Optimal storage design parameters in terms of the temperature differences in the heat exchanger and the storage capacity have been determined which can further increase the net present value of such system.

  1. Analytical 1D models of the wall thermal resistance of rectangular minichannels applied in heat exchangers

    Directory of Open Access Journals (Sweden)

    Rybiński Witold

    2016-09-01

    Full Text Available The paper presents four 1-dimensional models of thermal resistance of walls in a heat exchanger with rectangular minichannels. The first model is the simplest one, with a single wall separating two fluids. The second model of the so called equivalent wall takes into account total volume of intermediate walls between layers of minichannels and of side walls of minichannels. The next two more complicated models take separately into account thermal resistance of these walls. In these two models side walls are treated as fins. The results of models comparison are presented. It is shown that thermal resistance may be neglected for metal walls but it should be taken into account for the walls made of plastics. For the case of non-neglected wall thermal resistance the optimum wall thickness was derived. Minichannel heat exchangers made of plastic are larger than those built of metal, but are significantly cheaper. It makes possible to use of such exchangers in inexpensive microscale ORC installations.

  2. On the Importance of the Heat and Mass Transfer Resistances in Internally-Cooled Liquid Desiccant Dehumidifiers and Regenerators

    Energy Technology Data Exchange (ETDEWEB)

    Woods, Jason D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kozubal, Eric J [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-02-06

    Liquid desiccant heat and mass exchangers are a promising technology for efficient humidity control in buildings. Many researchers have investigated these exchangers, often using numerical models to predict their performance. However, there is a lack of information in the literature on the magnitude of the heat and mass transfer resistances, both for the dehumidifier (which absorbs moisture from the air) and the regenerator (which heats the liquid desiccant to re-concentrate it). This article focuses on internally-cooled, 3-fluid exchangers in a parallel plate geometry. Water heats or cools a desiccant across a plate, and the desiccant absorbs or releases water into an airstream through a membrane. A sensitivity analysis was used to estimate the importance of each of the heat and mass transfer resistances (air, membrane, desiccant, plate, water), and how it changes with different design geometries. The results show that, for most designs, the latent and sensible heat transfer of the dehumidifier is dominated by the air mass transfer resistance and air heat transfer resistance, respectively. The air mass transfer resistance is also important for the regenerator, but much less so; the change in the desiccant equilibrium humidity ratio due to a change in either temperature or desiccant mass fraction is much higher at the regenerator's higher temperatures. This increases the importance of (1) getting heat from the water to the desiccant/membrane interface, and (2) diffusing salt ions quickly away from the desiccant/membrane interface. The membrane heat transfer and water heat transfer resistances were found to be the least important. These results can help inform decisions about what simplifying assumptions to make in numerical models, and can also help in designing these exchangers by understanding which resistances are most important.

  3. Phase Change Material Systems for High Temperature Heat Storage.

    Science.gov (United States)

    Perraudin, David Y S; Binder, Selmar R; Rezaei, Ehsan; Ortonaa, Alberto; Haussener, Sophia

    2015-01-01

    Efficient, cost effective, and stable high-temperature heat storage material systems are important in applications such as high-temperature industrial processes (metal processing, cement and glass manufacturing, etc.), or electricity storage using advanced adiabatic compressed air energy storage. Incorporating phase change media into heat storage systems provides an advantage of storing and releasing heat at nearly constant temperature, allowing steady and optimized operation of the downstream processes. The choice of, and compatibility of materials and encapsulation for the phase change section is crucial, as these must guarantee good and stable performance and long lifetime at low cost. Detailed knowledge of the material properties and stability, and the coupled heat transfer, phase change, and fluid flow are required to allow for performance and lifetime predictions. We present coupled experimental-numerical techniques allowing prediction of the long-term performance of a phase change material-based high-temperature heat storage system. The experimental investigations focus on determination of material properties (melting temperature, heat of fusion, etc.) and phase change material and encapsulation interaction (stability, interface reactions, etc.). The computational investigations focus on an understanding of the multi-mode heat transfer, fluid flow, and phase change processes in order to design the material system for enhanced performance. The importance of both the experimental and numerical approaches is highlighted and we give an example of how both approaches can be complementarily used for the investigation of long-term performance.

  4. Experimental investigation of combined heat recovery and power generation using a heat pipe assisted thermoelectric generator system

    International Nuclear Information System (INIS)

    Remeli, Muhammad Fairuz; Date, Abhijit; Orr, Bradley; Ding, Lai Chet; Singh, Baljit; Affandi, Nor Dalila Nor; Akbarzadeh, Aliakbar

    2016-01-01

    Highlights: • A new passive combined heat recovery and power generation system was tested. • Heat pipes and thermoelectrics were used for recovering industrial waste heat. • The system could recover approximately 1079 W of heat and produce approximately 7 W of electric power. - Abstract: This paper explores a new method of recovering industrial waste heat and conversion to electricity using a Thermo-Electric Generator (TEG). For this purpose, a lab scale bench-top prototype of waste heat recovery and electricity conversion system was designed and fabricated. This bench top system consists of Bismuth Telluride (Bi 2 Te 3 ) based TEG sandwiched between two heat pipes. The first heat pipe was connected to the hot side of the TEG and the second to the cold side of TEG. The waste heat was simulated by using a 2 kW electric heater for heating the air in the system. Experiments were conducted to evaluate the system performance in terms of the heat transfer rate, heat exchanger effectiveness, and maximum output power. It was found that the highest heat exchanger effectiveness of 41% was achieved when the airspeed was set at 1.1 m/s. The system could recover around 1079 W of heat and produce around 7 W of electric power. This equated to 0.7% of thermal-to-electric conversion efficiency. The theoretical predictions showed good agreement compared to the experimental results.

  5. Fast plasma heating by anomalous and inertial resistivity effects in the solar atmosphere

    Science.gov (United States)

    Duijveman, A.; Hoyng, P.; Ionson, J. A.

    1981-01-01

    A simple model is presented to describe fast plasma heating by anomalous and inertial resistivity effects. It is noted that a small fraction of the plasma contains strong currents that run parallel to the magnetic field and are driven by an exponentiating electric field. The anomalous character of the current dissipation derives from the excitation of electrostatic ion-cyclotron and/or ion-acoustic waves. The possible role of resistivity deriving from geometrical effects ('inertial resistivity') is also considered. Using a marginal stability analysis, equations for the average electron and ion temperatures are derived and numerically solved. No loss mechanisms are taken into account. The evolution of the plasma is described as a path in the drift velocity diagram, where the drift velocity is plotted as a function of the electron to ion temperature ratio.

  6. Effect of the deposition conditions of platinum electrodes on their performance as resistive heating elements

    Directory of Open Access Journals (Sweden)

    Andrei Ionut Mardare

    2004-09-01

    Full Text Available The performance of different platinum electrodes used as resistive heating elements was studied. Pt films having different thickness were deposited by RF magnetron sputtering at room temperature followed by post-deposition annealing at 700 ºC or made in-situ at 700 ºC. The Pt films were deposited over oxidized silicon, using Ti or Zr buffer layers. The resistance dependence on temperature was studied by applying increasing currents (up to 2A to the Pt films. Changes in the microstructure of the Pt films account for the changes in the temperature coefficient of resistance as a function of the deposition parameters. The maximum substrate temperature (675 ºC was obtained when using 200 nm Pt films deposited at 700 ºC over Ti, with a power consumption of only 16 W.

  7. Solar heating system installed at Jackson, Tennessee. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-10-01

    The solar energy heating system installed at the Coca-Cola Bottling Works in Jackson, Tennessee is described. The system consists of 9480 square feet of Owens-Illinois evacuated tubular solar collectors with attached specular cylindrical reflectors and will provide space heating for the 70,000 square foot production building in the winter, and hot water for the bottle washing equipment the remainder of the year. Component specifications and engineering drawings are included. (WHK)

  8. Effect of variable heat input on the heat transfer characteristics in an Organic Rankine Cycle system

    Directory of Open Access Journals (Sweden)

    Aboaltabooq Mahdi Hatf Kadhum

    2016-01-01

    Full Text Available This paper analyzes the heat transfer characteristics of an ORC evaporator applied on a diesel engine using measured data from experimental work such as flue gas mass flow rate and flue gas temperature. A mathematical model was developed with regard to the preheater, boiler and the superheater zones of a counter flow evaporator. Each of these zones has been subdivided into a number of cells. The hot source of the ORC cycle was modeled. The study involves the variable heat input's dependence on the ORC system's heat transfer characteristics, with especial emphasis on the evaporator. The results show that the refrigerant's heat transfer coefficient has a higher value for a 100% load from the diesel engine, and decreases with the load decrease. Also, on the exhaust gas side, the heat transfer coefficient decreases with the decrease of the load. The refrigerant's heat transfer coefficient increased normally with the evaporator's tube length in the preheater zone, and then increases rapidly in the boiler zone, followed by a decrease in the superheater zone. The exhaust gases’ heat transfer coefficient increased with the evaporator’ tube length in all zones. The results were compared with result by other authors and were found to be in agreement.

  9. Radiant heat transfer network in the simulated protective clothing ; System under high heat flux

    NARCIS (Netherlands)

    Fukazawa, T.; Hartog, E.A. den; Daanen, H.A.M.; Penders-van Elk, N.; Tochihara, Y.; Havenith, G.

    2005-01-01

    A radiant network model was developed for design of the protective clothing system against solar and infrared radiative heat flux. A one-dimensional model was employed in the present study, because the aim of this study was to obtain precise temperature distribution through the system with use of a

  10. Effects of composite scale on high temperature oxidation resistance of Fe-Cr-Ni heat resistant alloy

    Directory of Open Access Journals (Sweden)

    Wang Haitao

    2009-05-01

    Full Text Available Fe-Cr-Ni heat resistant alloys with aluminum and silicon addition, alone and in combination, were melted using an intermediate frequency induction furnace with a non-oxidation method. By the oxidation weight gain method, the oxidation resistances of the test alloys were determined at 1,200 ìC for 500 hours. According to the oxidation weight gains, the oxidation kinetic curves were plotted and the functions were regressed by the least squares method. The results show that the oxidation kinetic curves follow the power function of y = axb (a>0, 0resistance were studied further by analyses using X-ray diffraction (XRD and scanning electron microscope (SEM. It is found that the composite scale compounds of Cr2O3, メ-Al2O3, SiO2 and FeCr2O4, with compact structure and tiny grains, shows complete oxidation resistance at 1,200 ìC. When the composite scale lacks メ-Al2O3 or SiO2, it becomes weak in oxidation resistance with a loose structure. By the criterion of standard Gibbs formation free energy, the model of the nucleation and growth of the composite scale is established. The forming of the composite scale is the result of the competition of being oxidized and reduced between aluminum, silicon and the matrix metal elements of iron, chromium and nickel. The protection of the composite scale is analyzed essentially by electrical conductivity and strength properties.

  11. “Walczak’s Pipes” in the Greenhouse Heating System

    Directory of Open Access Journals (Sweden)

    Kazimierz Rutkowski

    2016-01-01

    Full Text Available Diversified heating circuits inertia is particularly important by high variability of external conditions were the greenhouse is often overheated or large heat losses are noted. To meet these needs a new generation of heating pipes were used. They are hexagram-shaped pipes called “Walczak’s pipe”. Tubes of such shape have several times smaller volume in comparison with traditional heating pipes of the same outer diameter and higher stiffness. The preliminary assessment of the “Walczak’s pipe” installed in the greenhouse is highly positive. Compared with the traditional system it enables better heat management. In the first research stage, the thermal efficiency was defined in different ambient conditions at selected flow parameters and various water temperatures. With regard to the accepted flow values, it is notable that “Walczak’s pipe” has greater thermal efficiency per unit of power comparing with traditional tube. During the study, there was also a thermographic analysis of pipes’ surface performed and the heat flow distribution was determined. Analyzing the temperature distribution on the “Walczak’s pipe” remarkable are the areas with higher values ​​comparing with standard tube. It can be concluded that in the heating system with “Walczak’s pipe” energy transferred by radiation increases. This is particularly advantageous solution to use in greenhouses. It allows to obtain a higher leafs temperature with respect to the ambient temperature (vegetation heating. This parameter has a beneficial effect on the vegetative growth of cultivated plants.

  12. Heating control system for nuclear reactor

    International Nuclear Information System (INIS)

    Shinohara, Kaoru.

    1981-01-01

    Purpose: To automatically control reactor heating while keeping the condition of temperature rising rate by determining the deviations based on the reactor water temperature, the aimed temperature and the aimed temperature rising rate and operating control rods. Constitution: Actual temperature in the reactor is measured by a temperature detector and compared with a value from a setter to determine the temperature deviation. While on the other hand, the rising rate for the measured temperature is calculated in a differentiator and compared with a value from a setter to determine the deviation, which is passed through an integrator to calculate the deviation for the temperature rising rate. The signals for the temperature deviation and the temperature rising rate deviation are selected in a lower value preference circuit and the operation amount for the control rod is judged in a control rod operation judging section depending on the deviation amount. The control rod to be operated is determined in a sequence control section for the selection of control rod. The control rod selected and the direction of the operation are displayed on a display and the selected control rod is automatically driven by a control rod drives to thereby carry our reactor heating. (Furukawa, Y.)

  13. Optimizing the Heat Exchanger Network of a Steam Reforming System

    DEFF Research Database (Denmark)

    Nielsen, Mads Pagh; Korsgaard, Anders Risum; Kær, Søren Knudsen

    2004-01-01

    Proton Exchange Membrane (PEM) based combined heat and power production systems are highly integrated energy systems. They may include a hydrogen production system and fuel cell stacks along with post combustion units optionally coupled with gas turbines. The considered system is based on a natural...... gas steam reformer along with gas purification reactors to generate clean hydrogen suited for a PEM stack. The temperatures in the various reactors in the fuel processing system vary from around 1000°C to the stack temperature at 80°C. Furthermore, external heating must be supplied to the endothermic...

  14. Solar systems and heat pumps in operation in Carinthia: results 1994 - 1997

    International Nuclear Information System (INIS)

    Faninger, G.

    1998-04-01

    Solar systems and heat pumps in operation in Carinthia: results 1994 - 1997. Test results from solar systems for swimming pool heating, hot water preparation and space heating as well as heat pumps for hot water preparation, space heating and heat recovery will be reported and assessed collectively. (author)

  15. Optimization of solar water heating systems through water replenishment

    International Nuclear Information System (INIS)

    Kulkarni, Govind N.; Kedare, Shireesh B.; Bandyopadhyay, Santanu

    2009-01-01

    In a typical solar water heating system, cold water is replenished into the storage tank as soon as the load is served. However, it is possible to determine the water replenishment profile (i.e., the quantity of the cold makeup water to be supplied to the storage tank over a day) that optimizes the overall system. In this paper, the effect of water replenishment on the system sizing is studied and a novel strategy for water replenishment is proposed to improve the design and performance of solar water heating systems. Based on an analytical technique, an approximate water replenishment profile is proposed to size a solar water heating system near-optimally. The problem is analyzed using a methodology called design space approach. Design space of a solar water heating system identifies all possible and feasible designs on a collector area vs. storage volume diagram. For illustration of the proposed methodology, an example problem is solved. It is observed that the annualized system cost can be reduced by 13.7%. For the cost-optimal system configuration, a reduction of 12.7% in the collector area and 10.2% reduction in the storage volume are observed. The proposed methodology is particularly important and advantageous for large commercial and industrial solar water heating systems

  16. Parametric Integral Equations Systems Method In Solving Unsteady Heat Transfer Problems For Laser Heated Materials

    Directory of Open Access Journals (Sweden)

    Sawicki Dominik

    2015-09-01

    Full Text Available One of the most popular applications of high power lasers is heating of the surface layer of a material, in order to change its properties. Numerical methods allow an easy and fast way to simulate the heating process inside of the material. The most popular numerical methods FEM and BEM, used to simulate this kind of processes have one fundamental defect, which is the necessity of discretization of the boundary or the domain. An alternative to avoid the mentioned problem are parametric integral equations systems (PIES, which do not require classical discretization of the boundary and the domain while being numerically solved. PIES method was previously used with success to solve steady-state problems, as well as transient heat transfer problems. The purpose of this paper is to test the efficacy of the PIES method with time discretization in solving problem of laser heating of a material, with different pulse shape approximation functions.

  17. Heat transfer studies in a spiral plate heat exchanger for water: palm oil two phase system

    Directory of Open Access Journals (Sweden)

    S. Ramachandran

    2008-09-01

    Full Text Available Experimental studies were conducted in a spiral plate heat exchanger with hot water as the service fluid and the two-phase system of water – palm oil in different mass fractions and flow rates as the cold process fluid. The two phase heat transfer coefficients were correlated with Reynolds numbers (Re in the form h = a Re m, adopting an approach available in literature for two phase fluid flow. The heat transfer coefficients were also related to the mass fraction of palm oil for identical Reynolds numbers. The two-phase multiplier (ratio of the heat transfer coefficient of the two phase fluid and that of the single phase fluid was correlated with the Lockhart Martinelli parameter in a polynomial form. This enables prediction of the two-phase coefficients using single-phase data. The predicted coefficients showed a spread of ± 10 % in the laminar range.

  18. Soil temperature distribution around a U-tube heat exchanger in a multi-function ground source heat pump system

    International Nuclear Information System (INIS)

    Li Shuhong; Yang Weihua; Zhang Xiaosong

    2009-01-01

    The imbalance of heat extracted from the earth by the underground heat exchangers in winter and ejected into it in summer is expected to affect the long term performance of conventional ground source heat pump (GSHP) in territories with a cold winter and a warm summer such as the middle and downstream areas of the Yangtze River in China. This paper presents a new multi-function ground source heat pump (MFGSHP) system which supplies hot water as well as space cooling/heating to mitigate the soil imbalance of the extracted and ejected heat by a ground source heat pump system. The heat transfer characteristic is studied and the soil temperature around the underground heat exchangers are simulated under a typical climatic condition of the Yangtze River. A three-dimensional model was constructed with the commercial computational fluid dynamics software FLUENT based on the inner heat source theory. Temperature distribution and variation trend of a tube cluster of the underground heat exchanger are simulated for the long term performance. The results show that the soil temperature around the underground tube keeps increasing due to the surplus heat ejected into the earth in summer, which deteriorates the system performance and may lead to the eventual system deterioration. The simulation shows that MFGSHP can effectively alleviate the temperature rise by balancing the heat ejected to/extracted from underground by the conventional ground source heat pump system. The new system also improves the energy efficiency.

  19. Solar heating system at Security State Bank, Starkville, Mississippi. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-08-01

    Information is provided on the Solar Energy Heating System (airtype) installed at the branch bank building, northwest corner of Highway 12 and Spring Street, Starkville, Mississippi. This installation was completed in June, 1979. The 312 square feet of Solaron flat plate air collectors provide for 788 square feet of space heating, an estimated 55 percent of the heating load. Solar heated air is distributed to the 96 cubic foot steel cylinder, which contains two inch diameter rocks. An air handler unit moves the air over the collector and into the steel cylinder. Four motorized dampers and two gravity dampers are also part of the system. A Solaron controller which has sensors located at the collectors, rock storage, and at the return air, automatically controls the system. Auxiliary heating energy is provided by electric resistance duct heaters. This project is part of the US Department of Energy's Solar Demonstration Program with the government sharing $14,201 of the $17,498 solar energy system installation cost. This system was acceptance tested February, 1980, and the demonstration period ends in 1985.

  20. Heat resistance and the effects of continuous pasteurization on the inactivation of Byssochlamys fulva ascospores in clarified apple juice.

    Science.gov (United States)

    Sant'ana, A S; Rosenthal, A; Massaguer, P R

    2009-07-01

    To determine thermal resistance, the effect of pasteurization temperature variations (c. 2 degrees C) in a continuous system in the number of decimal reductions (n) of a Byssochlamys strain in clarified apple juice (CAJ). Thermal destruction kinetics of Byssochlamys fulva IOC 4518 in thermal death tubes were determined at 85 degrees , 90 degrees , 92 degrees and 95 degrees C by using Weibull distribution frequency model. Three processes with different heating and holding temperatures (A: 94 degrees , 92 degrees C; B: 95 degrees , 93 degrees C; C: 96 degrees , 94 degrees C, respectively) were performed in a continuous system. Process time was 30 s. delta (time of first decimal reduction) values were: 42.98, 8.10, 3.62 and 1.81 min. Variable n ranged from 0.16 to >4.78 for process B (equivalent to industrial). Variable n (0.95-2.66 log CFU ml(-1)) were obtained in CAJ bottles processed under condition B, while process A resulted in total heat-resistant mould (HRM) survival and process C in total HRM destruction. This study demonstrates that small variations in temperature during the CAJ pasteurization could result in elimination or survival of HRM due to its nonlogarithmic behaviour. This was the first study to use Weibull frequency method to model inactivation of HRM in fruit juices. Temperature variations could culminate in the presence of HRM in pasteurized juices even when low counts (<10 spores per 100 ml) were present in the raw materials.

  1. Influence of ambient temperatures on performance of a CO2 heat pump water heating system

    International Nuclear Information System (INIS)

    Yokoyama, Ryohei; Shimizu, Takeshi; Ito, Koichi; Takemura, Kazuhisa

    2007-01-01

    In residential applications, an air-to-water CO 2 heat pump is used in combination with a domestic hot water storage tank, and the performance of this system is affected significantly not only by instantaneous ambient air and city water temperatures but also by hourly changes of domestic hot water consumption and temperature distribution in the storage tank. In this paper, the performance of a CO 2 heat pump water heating system is analyzed by numerical simulation. A simulation model is created based on thermodynamic equations, and the values of model parameters are estimated based on measured data for existing devices. The calculated performance is compared with the measured one, and the simulation model is validated. The system performance is clarified in consideration of seasonal changes of ambient air and city water temperatures

  2. Survival and Heat Resistance of Salmonella enterica and Escherichia coli O157:H7 in Peanut Butter ▿ †

    Science.gov (United States)

    He, Yingshu; Guo, Dongjing; Yang, Jingyun; Tortorello, Mary Lou; Zhang, Wei

    2011-01-01

    Significant differences (P butter with different formulations and water activity. High carbohydrate content in peanut butter and low incubation temperature resulted in higher levels of bacterial survival during storage but lower levels of bacterial resistance to heat treatment. PMID:21965404

  3. Survival and heat resistance of Salmonella enterica and Escherichia coli O157:H7 in peanut butter.

    Science.gov (United States)

    He, Yingshu; Guo, Dongjing; Yang, Jingyun; Tortorello, Mary Lou; Zhang, Wei

    2011-12-01

    Significant differences (P butter with different formulations and water activity. High carbohydrate content in peanut butter and low incubation temperature resulted in higher levels of bacterial survival during storage but lower levels of bacterial resistance to heat treatment.

  4. Technoeconomic analysis of a biomass based district heating system

    International Nuclear Information System (INIS)

    Zhang, H.; Ugursal, V.I.; Fung, A.

    2005-01-01

    This paper discussed a proposed biomass-based district heating system to be built for the Pictou Landing First Nation Community in Nova Scotia. The community centre consists of 6 buildings and a connecting arcade. The methodology used to size and design heating, ventilating and air conditioning (HVAC) systems, as well as biomass district energy systems (DES) were discussed. Annual energy requirements and biomass fuel consumption predictions were presented, along with cost estimates. A comparative assessment of the system with that of a conventional oil fired system was also conducted. It was suggested that the design and analysis methodology could be used for any similar application. The buildings were modelled and simulated using the Hourly Analysis Program (HAP), a detailed 2-in-1 software program which can be used both for HVAC system sizing and building energy consumption estimation. A techno-economics analysis was conducted to justify the viability of the biomass combustion system. Heating load calculations were performed assuming that the thermostat was set constantly at 22 degrees C. Community centre space heating loads due to individual envelope components for 3 different scenarios were summarized, as the design architecture for the buildings was not yet finalized. It was suggested that efforts should be made to ensure air-tightness and insulation levels of the interior arcade glass wall. A hydronic distribution system with baseboard space heating units was selected, comprising of a woodchip boiler, hot water distribution system, convective heating units and control systems. The community has its own logging operation which will provide the wood fuel required by the proposed system. An outline of the annual allowable harvest covered by the Pictou Landing Forestry Management Plan was presented, with details of proposed wood-chippers for the creation of biomass. It was concluded that the woodchip combustion system is economically preferable to the

  5. Heat-resistant, extended-spectrum β-lactamase-producing Klebsiella pneumoniae in endoscope-mediated outbreak

    DEFF Research Database (Denmark)

    Jørgensen, S.B.; Bojer, Martin Saxtorph; Boll, E.J.

    2016-01-01

    disinfection in a decontaminator designated for such use. The genetic marker clpK, which increases microbial heat resistance, has previously been described in K. pneumoniae outbreak strains. Aim To investigate the role of clpK in biofilm formation and heat-shock stability in the outbreak strain. Methods...... construction and heat-shock assays. Findings Five patients and one intubation endoscope contained K. pneumoniae with the same amplified fragment length polymorphism pattern. The outbreak strain contained the clpK genetic marker, which rendered the strain its increased heat resistance. The survival rate....... Heat resistance of certain K. pneumoniae strains may facilitate survival in biofilms on medical equipment and hence increase the potential of those strains to persist and disperse in the hospital environment....

  6. Thermoelectric Generators for Automotive Waste Heat Recovery Systems Part I: Numerical Modeling and Baseline Model Analysis

    Science.gov (United States)

    Kumar, Sumeet; Heister, Stephen D.; Xu, Xianfan; Salvador, James R.; Meisner, Gregory P.

    2013-04-01

    A numerical model has been developed to simulate coupled thermal and electrical energy transfer processes in a thermoelectric generator (TEG) designed for automotive waste heat recovery systems. This model is capable of computing the overall heat transferred, the electrical power output, and the associated pressure drop for given inlet conditions of the exhaust gas and the available TEG volume. Multiple-filled skutterudites and conventional bismuth telluride are considered for thermoelectric modules (TEMs) for conversion of waste heat from exhaust into usable electrical power. Heat transfer between the hot exhaust gas and the hot side of the TEMs is enhanced with the use of a plate-fin heat exchanger integrated within the TEG and using liquid coolant on the cold side. The TEG is discretized along the exhaust flow direction using a finite-volume method. Each control volume is modeled as a thermal resistance network which consists of integrated submodels including a heat exchanger and a thermoelectric device. The pressure drop along the TEG is calculated using standard pressure loss correlations and viscous drag models. The model is validated to preserve global energy balances and is applied to analyze a prototype TEG with data provided by General Motors. Detailed results are provided for local and global heat transfer and electric power generation. In the companion paper, the model is then applied to consider various TEG topologies using skutterudite and bismuth telluride TEMs.

  7. Diesel particulate filter (DPF) regeneration by electrical heating of resistive coatings

    Science.gov (United States)

    Williamson, Weldon S [Malibu, CA; Gonze, Eugene V [Pinckney, MI

    2008-12-30

    An exhaust system that processes exhaust generated by an engine includes a diesel particulate filter (DPF) that is disposed downstream of the engine and that filters particulates from the exhaust. An electrical heater is integrally formed in an upstream end of the DPF and selectively heats the exhaust to initiate combustion of the particulates within the exhaust as it passes therethrough. Heat generated by combustion of the particulates induces combustion of particulates within the DPF.

  8. Dynamic behavior of district heating systems. 1. Report

    International Nuclear Information System (INIS)

    Kunz, J.

    1993-01-01

    In this study a comprehensive model simulating the dynamic behavior of an entire district heating system has been developed. The model consists of four partial models, namely a model of the hydraulic behavior of a heat distribution network, another model of the thermal behavior of this network, a model of the heat generation plants and one of the heat consumers connected to the system. For the hydraulic simulation of the distribution network, a classical steady state approach has proved to be sufficient. The evolution of the temperatures in the network is given by the equation of transport. A numerical resolution scheme, which is adapted to the special case of a heat distribution network was developed for this equation. The model developed for the heating plant is simple but it is sufficiently detailed to determine the operation of its elements. A more complex model would take much more calculation time, but with such a simple model, it is possible to include it in the global model of the entire system. Each heat consumer is represented by a simple one cell model. The difficulty in such an approach is to determine the characteristics of each building in a simple manner. A classification, which allows to find the essential parameters from few and easily available data, has been defined. This model is not sufficiently accurate to calculate the thermal behavior of one specific building but it allows to determine the average dynamic evolution of the heat demand for a set of buildings with a good precision.The developed models have been programmed on a personal computer and the entire district heating network of the city of Lausanne has been simulated with this calculation code. Measurements have been taken on this network and the comparison with calculated results has allowed to calibrate the model. The comparison of measurements and calculations shows, that each part of the system is simulated realistically by the proposed model. (author) figs., tabs., refs

  9. Development of hybrid solar-assisted cooling/heating system

    KAUST Repository

    Huang, B.J.

    2010-08-01

    A solar-assisted ejector cooling/heating system (SACH) was developed in this study. The SACH combines a pump-less ejector cooling system (ECS) with an inverter-type heat pump (R22) and is able to provide a stable capacity for space cooling. The ECS is driven by solar heat and is used to cool the condenser of the R22 heat pump to increase its COP and reduce the energy consumption of the compressor by regulating the rotational speed of the compressor through a control system. In a complete SACH system test run at outdoor temperature 35 °C, indoor temperature 25 °C and compressor speed 20-80 Hz, and the ECS operating at generator temperature 90 °C and condensing temperature 37 °C, the corresponding condensing temperature of the heat pump in the SACH is 24.5-42 °C, cooling capacity 1.02-2.44 kW, input power 0.20-0.98 kW, and cooling COPc 5.11-2.50. This indicates that the use of ECS in SACH can effectively reduce the condensing temperature of the heat pump by 12.6-7.3 °C and reduce the power consumption by 81.2-34.5%. The SACH can also supply heat from the heat pump. At ambient temperature from 5 °C to 35 °C, the heating COPh is in the range 2.0-3.3. © 2010 Elsevier Ltd. All rights reserved.

  10. Heat savings in energy systems with substantial distributed generation

    DEFF Research Database (Denmark)

    Østergaard, PA

    2003-01-01

    . A lowered district heating demand and thereby lowered CHP-bound electricity generation would appear to increase the possibility of integration wind power but due to the ancillary services supplied by CHP plants, the situation is in fact the opposite. Heat savings may not be technically feasible......, if a certain production is required regardless of whether over-all electricity generation is sufficient. This article analyses this and although heat savings do have a negative impact on the amount of wind power the system may integrate a given moment in certain cases, associated fuel savings are notable......In Denmark, the integration of wind power is affected by a large amount of cogeneration of heat and power. With ancillary services supplied by large-scale condensation and combined heat and power (CHP) plants, a certain degree of large-scale generation is required regardless of momentary wind input...

  11. Assessment of retrofit automatic vent dampers for residential heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, D.L.; Wilson, R.P. Jr.; Ashley, L.E.; Butterfield, J.F.

    1977-11-01

    Automatic vent dampers are devices installed in the exhaust vent of a central heating system which prohibit the chimney flow of warm air from the dwelling space and from within the furnace when the heating system is not operating. An investigation of the effect of thermally actuated or electrically actuated dampers on home energy conservation, their cost, and safety is described. Eleven heating system types in 2 geographic regions were used in this study. It was determined that good quality, safe electrically actuated dampers are available in the U.S. and that thermally actuated units will be available soon; an average savings of approximately 8% in home heating cost could be achieved by using automatic dampers with suitable furnace systems in regions with a heating season of more than 4000 degree-days; the cost of the automatic dampers is from $65 to $140 with a payback period of 3 to 4 1/2 y; and, with the average heating system, vent damper retrofit alone is not as an attractive energy conservation option as combined vent damper, intermittent ignition device retrofit, and reduced gas orifice. (LCL)

  12. Ground Source Geothermal District Heating and Cooling System

    Energy Technology Data Exchange (ETDEWEB)

    Lowe, James William [Ball State Univ., Muncie, IN (United States)

    2016-10-21

    Ball State University converted its campus from a coal-fired steam boiler district heating system to a ground source heat pump geothermal district system that produces simultaneously hot water for heating and chilled water for cooling. This system will include the installation of 3,600 four hundred feet deep vertical closed loop boreholes making it the largest ground source geothermal district system in the country. The boreholes will act as heat exchangers and transfer heat by virtue of the earth’s ability to maintain an average temperature of 55 degree Fahrenheit. With growing international concern for global warming and the need to reduce worldwide carbon dioxide loading of the atmosphere geothermal is poised to provide the means to help reduce carbon dioxide emissions. The shift from burning coal to utilizing ground source geothermal will increase electrical consumption but an overall decrease in energy use and reduction in carbon dioxide output will be achieved. This achievement is a result of coupling the ground source geothermal boreholes with large heat pump chiller technology. The system provides the thermodynamic means to move large amounts of energy with limited energy input. Ball State University: http://cms.bsu.edu/About/Geothermal.aspx

  13. Proliferation resistance assessment of thermal recycle systems

    International Nuclear Information System (INIS)

    1979-02-01

    This paper examines the major proliferation aspects of thermal recycle systems and the extent to which technical or institutional measures could increase the difficulty or detectability of misuse of the system by would-be proliferators. It does this by examining the various activities necessary to acquire weapons-usable material using a series of assessment factors; resources required, time required, detectability. It is concluded that resistance to proliferation could be improved substantially by collecting reprocessing, conversion and fuel fabrication plants under multi national control and instituting new measures to protect fresh MOX fuel. Resistance to theft at sub-national level could be improved by co-location of sensitive facilities high levels of physical protection at plants and during transportation and possibly by adding a radiation barrier to MOX prior to shipment

  14. Prototype solar heating and cooling systems. Monthly progress reports

    Energy Technology Data Exchange (ETDEWEB)

    1978-10-01

    This report is a collection of monthly status reports from the AiResearch Manufacturing Company, who is developing eight prototype solar heating and cooling systems under NASA Contract NAS8-32091. This effort calls for the development, manufacture, test, system installation, maintenance, problem resolution, and performance evaluation. The systems are 3-, 25-, and 75-ton size units.

  15. New pre-heating system for natural gas pressure regulating stations

    International Nuclear Information System (INIS)

    Zullo, G.; Vertuani, C.; Borghesani, O.; Vignoli, F.

    1999-01-01

    Costs for running natural gas pressure regulating stations are mainly due to operation and maintenance of a natural gas preheating system, usually equipment with a hot water boiler or an armour-plated electric resistance immersed in a fluid. The article describe a system, considering a natural circulation boiler which uses steam/condensate (at 100 degrees C and 0,5 bar) as a thermal conductor, in thermodynamic balance and in absence of un condensable. This new boiler, already operating with satisfactory results in heating system for industrial buildings, does not require testing, notifications, periodical inspections by the competent authorities, constant monitoring by trained or patented staff. Besides, it allows easier installations procedures and running cost savings. The system, to be considered as static because it has no moving parts, is a good alternative to conventional forced hot water circulation or electric heating system [it

  16. Motier church - refurbishment of heating system; Kirche Motier Sanierung der Raumheizung

    Energy Technology Data Exchange (ETDEWEB)

    Grizzetti, V.

    2003-07-01

    This final report for the Swiss Federal Office for Energy describes the refurbishment of the space heating system of the historical church in Motier, Switzerland. The 50-year old, inefficient electrical direct heating system of the church, which is a listed building, and the new, heat pump-based system are described. Heating energy is distributed via a warm-air system, geothermal energy provides the primary heat source for the heat pump. Technical details of the heating characteristics and energy consumption of the old and new heating systems are presented in the form of tables and diagrams. The maintenance of the heating system's ventilation unit is also discussed.

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

    KAUST Repository

    Huang, Bin-Juine

    2012-11-01

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

  18. Load Prediction in District Heating Systems; Lastprognoser foer fjaerrvaerme

    Energy Technology Data Exchange (ETDEWEB)

    Kvarnstroem, Johan; Dotzauer, Erik; Gollvik, Lena; Andersson, Cari

    2007-12-15

    To produce heat and power is costly. Therefore it is important for the district heating companies to plan and optimize the production. The principal procedure is to first construct a prediction of the heat demand, and then, given the demand prediction, plan the production. Due to the complexity of the problem, the need for mathematical models is obvious. The common way to predict the heat demand is to use one single load curve for the whole district heating network. This has obvious drawbacks. With only one curve it is difficult to consider e.g. restrictions in distribution capacity and the dynamics in the network. The standard approach is also to base the predictions on delivered heat from the production plants. During the last few years it has become more common to measure the load directly at the consumer sites. This gives new opportunities for the construction of load predictions. Another type of information that is not exploited today is the fact that the consumption patterns differ for different categories of consumers. For example, the load profiles for a residential house and an office diverge. An alternative approach is then to consider this in the load prediction algorithm. The aim with current project is to investigate alternative methods for prediction of district heating demand. Focus is on how to exploit measurements from the consumer sites. Also the possibility to make predictions using physical models is discussed. Numerical results based on data from the district heating systems in Stockholm owned by Fortum are presented

  19. Ground-source heat pump systems in Norway

    International Nuclear Information System (INIS)

    Stene, Joern

    2007-01-01

    The Norwegian ground source heat pump (GSHP) market is reviewed. Boreholes in bedrock are of growing interest for residential systems and of growing interest for larger systems with thermal recharging or thermal energy storage. Ground water is limited to areas where the water has acceptable purity. Challenges and important boundary conditions include 1) high quality GSHP system requires engineering expertise, 2) new building codes and EU directive 'energy performance of buildings.'(2006), and 3) hydronic floor heating systems in 50 percent of new residences (author) (ml)

  20. Basic study for development of nuclear heat application systems

    Energy Technology Data Exchange (ETDEWEB)

    Inaba, Yoshitomo; Fumizawa, Motoo; Hishida, Makoto [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    1996-05-01

    We need to intensely investigate real possibilities of nuclear heat application systems which exploit high potential of nuclear energy as a promising candidate of the future energy resource in the world. In this report, special interest was placed on coal reforming systems because we thought a compact heat source of nuclear power with a very high energy density might compensate the environmental problem caused by burning a great amount of coal. First, we reviewed state-of-the-art technologies for coal reforming technology with a special attention on coal gasification technologies. Based on these basic data, we proposed several nuclear coal reforming systems and discussed advantages and disadvantages of the systems. We also explored a model with which we could analyze nuclear heat application systems all together. In addition, we investigated possibility and effects of nuclear heat utilization systems producing chemical materials from carbon dioxide in flue gas of fossil fuel power plant. As a result, we showed nuclear heat application systems were useful. (author).