WorldWideScience

Sample records for building thermal storage

  1. Thermal energy storage in buildings using PCM. Computer simulation

    Energy Technology Data Exchange (ETDEWEB)

    Khudhair, A.M.; Farid, M.M.; Chen, J.J.J. [Auckland Univ. (New Zealand). Dept. of Chemical and Materials Engineering; Bansal, P.K. [Auckland Univ. (New Zealand). Dept. of Mechanical Engineering

    2008-07-01

    This paper presents the results of phase changing material, RT20, impregnated up to 26%-wt into the gypsum wallboards to produce a significant thermal storage medium (PCMGW). A full-scale test facility using the PCMGW was monitored for two years, and was modeled using the thermal building simulation package, SUNREL, to evaluate the latent heat storage performance of the PCM treated wallboards. Measured and simulated results showed that the use of PCMGW met two needs: quick absorption of solar heat for use during off-sunshine hours and avoid overheating during sunshine hours. The PCMGWs effectively smoothed out diurnal daily fluctuations of indoor air temperatures on sunny days and, therefore, providing thermal comfort. Although the benefits of PCMGW were clearly demonstrated, it was necessary to optimize the melting point and quantity of the PCM and to highlight the importance of showing how many days the PCM could effectively minimize the indoor temperature fluctuation. In a 90-day period during summer, a PCM of with a melting range of 18 C - 22 C could be fully utilized for 39% and partially utilized for 55.5% of the summer days when there is either partial melting or partial freezing. There is no benefit for only 5.5% of the summer days when the PCM remains either in the solid or liquid state. These percentages show that the decision of using 26%-wt RT20 with the melting range of 18-22 C is a practical and realistic one. (orig.)

  2. Review on thermal performance of phase change energy storage building envelope

    Institute of Scientific and Technical Information of China (English)

    WANG Xin; ZHANG YinPing; XlAO Wei; ZENG RuoLang; ZHANG QunLi; DI HongFa

    2009-01-01

    Improving the thermal performance of building envelope is an important way to save building energy consumption. The phase change energy storage building envelope is helpful to effective use of renewable energy, reducing building operational energy consumption, increasing building thermal comfort, and reducing environment pollution and greenhouse gas emission. This paper presents the concept of ideal energy-saving building envelope, which is used to guide the building envelope material selection and thermal performance design. This paper reviews some available researches on phase change building material and phase change energy storage building envelope. At last, this paper presents some current problems needed further research.

  3. PCM thermal storage in buildings: A state of art

    Energy Technology Data Exchange (ETDEWEB)

    Tyagi, Vineet Veer; Buddhi, D. [Thermal Energy Storage Laboratory, School of Energy and Environmental Studies, Faculty of Engineering Science, Devi Ahilya University, Indore 452017 (India)

    2007-08-15

    A comprehensive review of various possible methods for heating and cooling in buildings are discussed in this paper. The thermal performance of various types of systems like PCM trombe wall, PCM wallboards, PCM shutters, PCM building blocks, air-based heating systems, floor heating, ceiling boards, etc., is presented in this paper. All systems have good potential for heating and cooling in building through phase change materials and also very beneficial to reduce the energy demand of the buildings. (author)

  4. Residential Solar-Based Seasonal Thermal Storage Systems in Cold Climates: Building Envelope and Thermal Storage

    OpenAIRE

    Alexandre Hugo; Radu Zmeureanu

    2012-01-01

    The reduction of electricity use for heating and domestic hot water in cold climates can be achieved by: (1) reducing the heating loads through the improvement of the thermal performance of house envelopes, and (2) using solar energy through a residential solar-based thermal storage system. First, this paper presents the life cycle energy and cost analysis of a typical one-storey detached house, located in Montreal, Canada. Simulation of annual energy use is performed using the TRNSYS softwar...

  5. Residential Solar-Based Seasonal Thermal Storage Systems in Cold Climates: Building Envelope and Thermal Storage

    Directory of Open Access Journals (Sweden)

    Alexandre Hugo

    2012-10-01

    Full Text Available The reduction of electricity use for heating and domestic hot water in cold climates can be achieved by: (1 reducing the heating loads through the improvement of the thermal performance of house envelopes, and (2 using solar energy through a residential solar-based thermal storage system. First, this paper presents the life cycle energy and cost analysis of a typical one-storey detached house, located in Montreal, Canada. Simulation of annual energy use is performed using the TRNSYS software. Second, several design alternatives with improved thermal resistance for walls, ceiling and windows, increased overall air tightness, and increased window-to-wall ratio of South facing windows are evaluated with respect to the life cycle energy use, life cycle emissions and life cycle cost. The solution that minimizes the energy demand is chosen as a reference house for the study of long-term thermal storage. Third, the computer simulation of a solar heating system with solar thermal collectors and long-term thermal storage capacity is presented. Finally, the life cycle cost and life cycle energy use of the solar combisystem are estimated for flat-plate solar collectors and evacuated tube solar collectors, respectively, for the economic and climatic conditions of this study.

  6. Energy system investment model incorporating heat pumps with thermal storage in buildings and buffer tanks

    DEFF Research Database (Denmark)

    Hedegaard, Karsten; Balyk, Olexandr

    2013-01-01

    options: passive heat storage in the building structure via radiator heating, active heat storage in concrete floors via floor heating, and use of thermal storage tanks for space heating and hot water. It is shown that the model is well qualified for analysing possibilities and system benefits...... be taken into account. In this study, we present a model that facilitates analysing individual heat pumps and complementing heat storages in integration with the energy system, while optimising both investments and operation. The model incorporates thermal building dynamics and covers various heat storage...

  7. Predictive Optimal Control of Active and Passive Building Thermal Storage Inventory

    Energy Technology Data Exchange (ETDEWEB)

    Gregor P. Henze; Moncef Krarti

    2005-09-30

    Cooling of commercial buildings contributes significantly to the peak demand placed on an electrical utility grid. Time-of-use electricity rates encourage shifting of electrical loads to off-peak periods at night and weekends. Buildings can respond to these pricing signals by shifting cooling-related thermal loads either by precooling the building's massive structure or the use of active thermal energy storage systems such as ice storage. While these two thermal batteries have been engaged separately in the past, this project investigated the merits of harnessing both storage media concurrently in the context of predictive optimal control. To pursue the analysis, modeling, and simulation research of Phase 1, two separate simulation environments were developed. Based on the new dynamic building simulation program EnergyPlus, a utility rate module, two thermal energy storage models were added. Also, a sequential optimization approach to the cost minimization problem using direct search, gradient-based, and dynamic programming methods was incorporated. The objective function was the total utility bill including the cost of reheat and a time-of-use electricity rate either with or without demand charges. An alternative simulation environment based on TRNSYS and Matlab was developed to allow for comparison and cross-validation with EnergyPlus. The initial evaluation of the theoretical potential of the combined optimal control assumed perfect weather prediction and match between the building model and the actual building counterpart. The analysis showed that the combined utilization leads to cost savings that is significantly greater than either storage but less than the sum of the individual savings. The findings reveal that the cooling-related on-peak electrical demand of commercial buildings can be considerably reduced. A subsequent analysis of the impact of forecasting uncertainty in the required short-term weather forecasts determined that it takes only very

  8. Thermal energy storage

    Science.gov (United States)

    1980-01-01

    The planning and implementation of activities associated with lead center management role and the technical accomplishments pertaining to high temperature thermal energy storage subsystems are described. Major elements reported are: (1) program definition and assessment; (2) research and technology development; (3) industrial storage applications; (4) solar thermal power storage applications; and (5) building heating and cooling applications.

  9. Preparation and characterization of phase change material for thermal energy storage in buildings

    Science.gov (United States)

    Lo, Tommy Y.

    2016-04-01

    The paper presents the developing of novel form-stable composite phase change material (PCM) by incorporation of paraffin into lightweight aggregate through vacuum impregnation. The macro-encapsulated Paraffin-lightweight aggregate is a chemical compatible, thermal stable and thermal reliable PCM material for thermal energy storage applications in buildings. The 28 days compressive strength of NWAC using PCM-LWA is 33 - 53 MPa, which has an opportunity for structural purpose. Scanning electronic microscopic images indicated the paraffin can be held inside the porous structure of the aggregate. Thermal performance test showed that the cement paste panel with composite PCM can reduce the indoor temperature.

  10. Predictive Optimal Control of Active and Passive Building Thermal Storage Inventory

    Energy Technology Data Exchange (ETDEWEB)

    Gregor P. Henze; Moncef Krarti

    2005-09-30

    Cooling of commercial buildings contributes significantly to the peak demand placed on an electrical utility grid. Time-of-use electricity rates encourage shifting of electrical loads to off-peak periods at night and weekends. Buildings can respond to these pricing signals by shifting cooling-related thermal loads either by precooling the building's massive structure or the use of active thermal energy storage systems such as ice storage. While these two thermal batteries have been engaged separately in the past, this project investigated the merits of harnessing both storage media concurrently in the context of predictive optimal control. To pursue the analysis, modeling, and simulation research of Phase 1, two separate simulation environments were developed. Based on the new dynamic building simulation program EnergyPlus, a utility rate module, two thermal energy storage models were added. Also, a sequential optimization approach to the cost minimization problem using direct search, gradient-based, and dynamic programming methods was incorporated. The objective function was the total utility bill including the cost of reheat and a time-of-use electricity rate either with or without demand charges. An alternative simulation environment based on TRNSYS and Matlab was developed to allow for comparison and cross-validation with EnergyPlus. The initial evaluation of the theoretical potential of the combined optimal control assumed perfect weather prediction and match between the building model and the actual building counterpart. The analysis showed that the combined utilization leads to cost savings that is significantly greater than either storage but less than the sum of the individual savings. The findings reveal that the cooling-related on-peak electrical demand of commercial buildings can be considerably reduced. A subsequent analysis of the impact of forecasting uncertainty in the required short-term weather forecasts determined that it takes only very

  11. Cold Thermal Storage and Peak Load Reduction for Office Buildings in Saudi Arabia

    Institute of Scientific and Technical Information of China (English)

    Nabil Y.Abdel-Shafi; Ramzy R.Obaid; Ibrahim M.Jomoah

    2014-01-01

    This paper involves the investigations of the chilled water and ice cold thermal storage technologies along with the associated operating strategies for the air conditioning (AC) systems of the typical office buildings in Saudi Arabia, so as to reduce the electricity energy consumption during the peak load periods. In Saudi Arabia, the extensive use of AC for indoor cooling in offices composes a large proportion of the annual peak electricity demand. The very high temperatures over long summer periods, extending from May to October, and the low cost of energy are the key factors in the wide and extensive use of air conditioners in the kingdom. This intense cooling load adds up to the requirement increase in the capacity of power plants, which makes them under utilized during the off-peak periods. Thermal energy storage techniques are one of the effective demand-side energy management methods. Systems with cold storage shifts all or part of the electricity requirement from peak hours to off-peak hours to reduce demand charges and/or take advantage of off-peak rates. The investigations reveal that the cold thermal energy storage techniques are effective from both technical and economic perspectives in the reduction of energy consumption in the buildings during peak periods.

  12. Thermal energy storage - A review of concepts and systems for heating and cooling applications in buildings

    DEFF Research Database (Denmark)

    Pavlov, Georgi Krasimiroy; Olesen, Bjarne W.

    2012-01-01

    period required, economic viability, and operating conditions. One of the main issues impeding the utilization of the full potential of natural and renewable energy sources, e.g., solar and geothermal, for space heating and space cooling applications is the development of economically competitive......The use of thermal energy storage (TES) in buildings in combination with space heating and/or space cooling has recently received much attention. A variety of TES techniques have developed over the past decades. TES systems can provide short-term storage for peak-load shaving as well as long......-term (seasonal) storage for the introduction of natural and renewable energy sources. TES systems for heating or cooling are utilized in applications where there is a time mismatch between the demand and the most economically favorable supply of energy. The selection of a TES system mainly depends on the storage...

  13. The integration of water loop heat pump and building structural thermal storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Marseille, T.J.; Schliesing, J.S.

    1991-10-01

    Many commercial buildings need heat in one part and, at the same time, cooling in another part. Even more common is the need for heating during one part of the day and cooling during another in the same spaces. If that energy could be shifted or stored for later use, significant energy might be saved. If a building's heating and cooling subsystems could be integrated with the building's structural mass and used to collect, store, and deliver energy, the energy might be save cost-effectively. To explore this opportunity, researchers at the Pacific Northwest Laboratory (PNL) examined the thermal interactions between the heating, ventilating, and air-conditioning (HVAC) system and the structure of a commercial building. Computer models were developed to simulate the interactions in an existing building located in Seattle, Washington, to determine how these building subsystems could be integrated to improve energy efficiency. The HVAC subsystems in the existing building were modeled. These subsystems consist of decentralized water-source heat pumps (WSHP) in a closed water loop, connected to cooling towers for heat rejection during cooling mode and boilers to augment heating. An initial base case'' computer model of the Seattle building, as-built, was developed. Metered data available for the building were used to calibrate this model to ensure that the analysis would provide information that closely reflected the operation of a real building. The HVAC system and building structure were integrated in the model using the concrete floor slabs as thermal storage media. The slabs may be actively charged during off-peak periods with the chilled water in the loop and then either actively or passively discharged into the conditioned space during peak periods. 21 refs., 37 figs., 17 tabs.

  14. Building Energy Storage Panel Based on Paraffin/Expanded Perlite: Preparation and Thermal Performance Study

    Directory of Open Access Journals (Sweden)

    Xiangfei Kong

    2016-01-01

    Full Text Available This study is focused on the preparation and performance of a building energy storage panel (BESP. The BESP was fabricated through a mold pressing method based on phase change material particle (PCMP, which was prepared in two steps: vacuum absorption and surface film coating. Firstly, phase change material (PCM was incorporated into expanded perlite (EP through a vacuum absorption method to obtain composite PCM; secondly, the composite PCM was immersed into the mixture of colloidal silica and organic acrylate, and then it was taken out and dried naturally. A series of experiments, including differential scanning calorimeter (DSC, scanning electron microscope (SEM, best matching test, and durability test, have been conducted to characterize and analyze the thermophysical property and reliability of PCMP. Additionally, the thermal performance of BESP was studied through a dynamic thermal property test. The results have showed that: (1 the surface film coating procedure can effectively solve the leakage problem of composite phase change material prepared by vacuum impregnation; (2 the optimum adsorption ratio for paraffin and EP was 52.5:47.5 in mass fraction, and the PCMP has good thermal properties, stability, and durability; and (3 in the process of dynamic thermal performance test, BESP have low temperature variation, significant temperature lagging, and large heat storage ability, which indicated the potential of BESP in the application of building energy efficiency.

  15. Thermal Energy Storage for Building Load Management: Application to Electrically Heated Floor

    Directory of Open Access Journals (Sweden)

    Hélène Thieblemont

    2016-07-01

    Full Text Available In cold climates, electrical power demand for space conditioning becomes a critical issue for utility companies during certain periods of the day. Shifting a portion or all of it to off-peak periods can help reduce peak demand and reduce stress on the electrical grid. Sensible thermal energy storage (TES systems, and particularly electrically heated floors (EHF, can store thermal energy in buildings during the off-peak periods and release it during the peak periods while maintaining occupants’ thermal comfort. However, choosing the type of storage system and/or its configuration may be difficult. In this paper, the performance of an EHF for load management is studied. First, a methodology is developed to integrate EHF in TRNSYS program in order to investigate the impact of floor assembly on the EHF performance. Then, the thermal comfort (TC of the night-running EHF is studied. Finally, indicators are defined, allowing the comparison of different EHF. Results show that an EHF is able to shift 84% of building loads to the night while maintaining acceptable TC in cold climate. Moreover, this system is able to provide savings for the customer and supplier if there is a significant difference between off-peak and peak period electricity prices.

  16. Dynamic Exergy Analysis for the Thermal Storage Optimization of the Building Envelope

    Directory of Open Access Journals (Sweden)

    Valentina Bonetti

    2017-01-01

    Full Text Available As a measure of energy “quality”, exergy is meaningful for comparing the potential for thermal storage. Systems containing the same amount of energy could have considerably different capabilities in matching a demand profile, and exergy measures this difference. Exergy stored in the envelope of buildings is central in sustainability because the environment could be an unlimited source of energy if its interaction with the envelope is optimised for maintaining the indoor conditions within comfort ranges. Since the occurring phenomena are highly fluctuating, a dynamic exergy analysis is required; however, dynamic exergy modelling is complex and has not hitherto been implemented in building simulation tools. Simplified energy and exergy assessments are presented for a case study in which thermal storage determines the performance of seven different wall types for utilising nocturnal ventilation as a passive cooling strategy. Hourly temperatures within the walls are obtained with the ESP-r software in free-floating operation and are used to assess the envelope exergy storage capacity. The results for the most suitable wall types were different between the exergy analysis and the more traditional energy performance indicators. The exergy method is an effective technique for selecting the construction type that results in the most favourable free-floating conditions through the analysed passive strategy.

  17. Modeling and optimization of energy generation and storage systems for thermal conditioning of buildings targeting conceptual building design

    Energy Technology Data Exchange (ETDEWEB)

    Grahovac, Milica

    2012-11-29

    The thermal conditioning systems are responsible for almost half of the energy consump-tion by commercial buildings. In many European countries and in the USA, buildings account for around 40% of primary energy consumption and it is therefore vital to explore further ways to reduce the HVAC (Heating, Ventilation and Air Conditioning) system energy consumption. This thesis investigates the relationship between the energy genera-tion and storage systems for thermal conditioning of buildings (shorter: primary HVAC systems) and the conceptual building design. Certain building design decisions irreversibly influence a building's energy performance and, conversely, many generation and storage components impose restrictions on building design and, by their nature, cannot be introduced at a later design stage. The objective is, firstly, to develop a method to quantify this influence, in terms of primary HVAC system dimensions, its cost, emissions and energy consumption and, secondly, to enable the use of the developed method by architects during the conceptual design. In order to account for the non-stationary effects of the intermittent renewable energy sources (RES), thermal storage and for the component part load efficiencies, a time domain system simulation is required. An abstract system simulation method is proposed based on seven pre-configured primary HVAC system models, including components such as boil-ers, chillers and cooling towers, thermal storage, solar thermal collectors, and photovoltaic modules. A control strategy is developed for each of the models and their annual quasi-stationary simulation is performed. The performance profiles obtained are then used to calculate the energy consumption, carbon emissions and costs. The annuity method has been employed to calculate the cost. Optimization is used to automatically size the HVAC systems, based on their simulation performance. Its purpose is to identify the system component dimensions that provide

  18. Experimental analysis of simulated reinforcement learning control for active and passive building thermal storage inventory

    Energy Technology Data Exchange (ETDEWEB)

    Liu, S. [Architectural Engineering, University of Nebraska-Lincoln, PKI 243, Omaha, NE (United States); Henze, G. P. [Architectural Engineering, University of Nebraska-Lincoln, PKI 203D, Omaha, NE (United States)

    2006-07-01

    This paper is the first part of a two-part investigation of a novel approach to optimally control commercial building passive and active thermal storage inventory. The proposed building control approach is based on simulated reinforcement learning, which is a hybrid control scheme that combines features of model-based optimal control and model-free learning control. An experimental study was carried out to analyze the performance of a hybrid controller installed in a full-scale laboratory facility. The first part presents an overview of the project with an emphasis on the theoretical foundation. The motivation of the research will be introduced first, followed by a review of past work. A brief introduction of the theory is provided including classic reinforcement learning and its variation, so-called simulated reinforcement learning, which constitutes the basic architecture of the hybrid learning controller. A detailed discussion of the experimental results will be presented in the companion paper. (author)

  19. Experimental analysis of simulated reinforcement learning control for active and passive building thermal storage inventory

    Energy Technology Data Exchange (ETDEWEB)

    Liu, S. [Architectural Engineering, University of Nebraska-Lincoln, PKI 243, Omaha, NE (United States); Henze, G. P. [Architectural Engineering, University of Nebraska-Lincoln, PKI 203D, Omaha, NE (United States)

    2006-07-01

    This paper is the second part of a two-part investigation of a novel approach to optimally control commercial building passive and active thermal storage inventory. The proposed building control approach is based on simulated reinforcement learning, which is a hybrid control scheme that combines features of model-based optimal control and model-free learning control. An experimental study was carried out to analyze the performance of a hybrid controller installed in a full-scale laboratory facility. The first paper introduced the theoretical foundation of this investigation including the fundamental theory of reinforcement learning control. This companion paper presents a discussion and analysis of the experimental results. The results confirm the feasibility of the proposed control approach. Operating cost savings were attained with the proposed control approach compared with conventional building control; however, the savings are lower than for the case of model-based predictive optimal control. As for the case of model-based predictive control, the performance of the hybrid controller is largely affected by the quality of the training model, and extensive real-time learning is required for the learning controller to eliminate any false cues it receives during the initial training period. Nevertheless, compared with standard reinforcement learning, the proposed hybrid controller is much more readily implemented in a commercial building. (author)

  20. Thermal energy storage for building heating and cooling applications. Quarterly progress report, April--June 1976

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, H.W.; Kedl, R.J.

    1976-11-01

    This is the first in a series of quarterly progress reports covering activities at ORNL to develop thermal energy storage (TES) technology applicable to building heating and cooling. Studies to be carried out will emphasize latent heat storage in that sensible heat storage is held to be an essentially existing technology. Development of a time-dependent analytical model of a TES system charged with a phase-change material was started. A report on TES subsystems for application to solar energy sources is nearing completion. Studies into the physical chemistry of TES materials were initiated. Preliminary data were obtained on the melt-freeze cycle behavior and viscosities of sodium thiosulfate pentahydrate and a mixture of Glauber's salt and Borax; limited melt-freeze data were obtained on two paraffin waxes. A subcontract was signed with Monsanto Research Corporation for studies on form-stable crystalline polymer pellets for TES; subcontracts are being negotiated with four other organizations (Clemson University, Dow Chemical Company, Franklin Institute, and Suntek Research Associates). Review of 10 of 13 unsolicited proposals received was completed by the end of June 1976.

  1. Optimization of a thermal storage unit combined with a biomass bioler for heating buildings

    OpenAIRE

    Butala, Vincenc; Stritih, Uroš

    2015-01-01

    The performance of a boiler with a built-in thermal storage unit is presented.The thermal storage unit is an insulated water tank that absorbs surplus heat from the boiler. The stored heat in the thermal storage unit makes it possible to heat even when the boiler is not operating, thus increasing the heating efficiency. A system with three components is described. The model of the system and the mathematical model were made using the TRNSYS program package and a test reference year (TRY). The...

  2. Seasonal thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.; Kannberg, L.D.; Raymond, J.R.

    1984-05-01

    This report describes the following: (1) the US Department of Energy Seasonal Thermal Energy Storage Program, (2) aquifer thermal energy storage technology, (3) alternative STES technology, (4) foreign studies in seasonal thermal energy storage, and (5) economic assessment.

  3. Dynamic Heat Storage and Cooling Capacity of a Concrete Deck with PCM and Thermally Activated Building System

    DEFF Research Database (Denmark)

    Pomianowski, Michal Zbigniew; Heiselberg, Per; Jensen, Rasmus Lund

    2012-01-01

    the performance of the new deck with PCM concrete is the thermal properties of such a new material, as the PCM concrete is yet to be well defined. The results presented in the paper include models in which the PCM concrete material properties, such as thermal conductivity, and specific heat capacity were first......This paper presents a heat storage and cooling concept that utilizes a phase change material (PCM) and a thermally activated building system (TABS) implemented in a hollow core concrete deck. Numerical calculations of the dynamic heat storage capacity of the hollow core concrete deck element...... with and without microencapsulated PCM are presented. The new concrete deck with microencapsulated PCM is the standard deck on which an additional layer of the PCM concrete was added and, at the same time, the latent heat storage was introduced to the construction. The challenge of numerically simulating...

  4. Advanced storage concepts for solar thermal systems in low energy buildings. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Furbo, S.; Andersen, Elsa; Schultz, Joergen M.

    2006-04-07

    The aim of Task 32 is to develop new and advanced heat storage systems which are economic and technical suitable as long-term heat storage systems for solar heating plants with a high degree of coverage. The project is international and Denmark's participation has focused on Subtask A, C, and D. In Subtask A Denmark has contributed to a status report about heat storage systems. In Subtask C Denmark has focused on liquid thermal storage tanks based on NaCH{sub 3}COO?3H{sub 2}O with a melting point of 58 deg. C. Theoretical and experimental tests have been conducted in order to establish optimum conditions for storage design. In Subtask D theoretical and experimental tests of optimum designs for advanced water tanks for solar heating plants for combined space heating and domestic hot water have been conducted. (BA)

  5. Design and Analysis of Phase Change Material based thermal energy storage for active building cooling: a Review

    Directory of Open Access Journals (Sweden)

    Nitin .D. Patil

    2012-06-01

    Full Text Available Phase Change Materials (PCMs are "latent" thermal storage materials. They use chemical bonds to store and release heat. The thermal energy transfer occurs when a material changes from a solid to a liquid orfrom a liquid to a solid form. This is called a change in state or "phase." Initially, these solid-liquid PCMs perform like conventional storage materials; their temperature rises as they absorb solar heat. Unlike conventional heat storage materials, when PCMs reach the temperature at which they change phase (their melting point, they absorb large amounts of heat without getting hotter. When the ambient temperature in the space around the PCM material drops, the Phase Change Material solidifies, releasing its stored latent heat. PCMs absorb and emit heat while maintaining a nearly constant temperature. Within the human comfort and electronic-equipment tolerance range of 20°C to 35°C, latent thermal storage materials are very effective.They can be used for equalization of day & night temperature and for transport of refrigerated products. In the proposed project heat of fusion of Cacl2. 6H2o as PCM is used for cooling water during night and this cooled water is used as circulating medium trough fan coil unit, air trough FCU will get cooled by transferring heat to water and fresh & cool air will be thrown in a room. In the proposed project FREE COOLING & ACTIVE BUILDING COOLING concepts of Thermal Energy Storage are used in combine

  6. Review of thermal energy storage technologies based on PCM application in buildings

    DEFF Research Database (Denmark)

    Pomianowski, Michal Zbigniew; Heiselberg, Per; Zhang, Yinping

    2013-01-01

    is paid to discussion and identification of proper methods to correctly determine the thermal properties of PCM materials and their composites and as well procedures to determine their energy storage and saving potential. The purpose of the paper is to highlight promising technologies for PCM application...

  7. A First-Order Study of Reduced Energy Consumption via Increased Thermal Capacitance with Thermal Storage Management in a Micro-Building

    Directory of Open Access Journals (Sweden)

    Mary B. Wilson

    2015-10-01

    Full Text Available This study uses a first-order approximation of a micro-building to investigate the major factors determining how increased thermal capacitance (ITC with thermal storage management (TSM can reduce energy consumption in locations with relatively mild weather conditions such as the southeastern part of the United States of America. In this study, ITC is achieved through water circulation between a large storage tank and pipes embedded within the building envelope. Although ITC results in a larger dominant time constant for the thermal response of a building, an adaptive allocation and control of the added capacitance through TSM significantly improves the benefits of the extra capacitance. This paper compares two first-order models for a micro-building: a reference case model with a single lumped thermal capacitance associated with the building, and another model, with the building’s capacitance plus the capacitance of the water system. Results showed that the ITC/TSM system reduced the cost of conditioning the building by reducing the operating time of both the cooling and the heating systems. May through September, the air conditioning operating time was reduced by an average of 70%, and October through April, the operation of the heating system was reduced by an average of 25%.

  8. Clathrate Hydrates for Thermal Energy Storage in Buildings: Overview of Proper Hydrate-Forming Compounds

    Directory of Open Access Journals (Sweden)

    Beatrice Castellani

    2014-09-01

    Full Text Available Increasing energy costs are at the origin of the great progress in the field of phase change materials (PCMs. The present work aims at studying the application of clathrate hydrates as PCMs in buildings. Clathrate hydrates are crystalline structures in which guest molecules are enclosed in the crystal lattice of water molecules. Clathrate hydrates can form also at ambient pressure and present a high latent heat, and for this reason, they are good candidates for being used as PCMs. The parameter that makes a PCM suitable to be used in buildings is, first of all, a melting temperature at about 25 °C. The paper provides an overview of groups of clathrate hydrates, whose physical and chemical characteristics could meet the requirements needed for their application in buildings. Simulations with a dynamic building simulation tool are carried out to evaluate the performance of clathrate hydrates in enhancing thermal comfort through the moderation of summer temperature swings and, therefore, in reducing energy consumption. Simulations suggest that clathrate hydrates have a potential in terms of improvement of indoor thermal comfort and a reduction of energy consumption for cooling. Cooling effects of 0.5 °C and reduced overheating hours of up to 1.1% are predicted.

  9. Dynamic thermal behavior of building using phase change materials for latent heat storage

    Directory of Open Access Journals (Sweden)

    Selka Ghouti

    2015-01-01

    Full Text Available This study presents a two-dimensional model with a real size home composed of two-storey (ground and first floor spaces separated by a slab, enveloped by a wall with rectangular section containing phase change material (PCM in order to minimize energy consumption in the buildings. The main objective of the PCM-wall system is to decrease the temperature change from outdoor space before it reaches the indoor space during the daytime. The numerical approach uses effective heat capacity Ceff model with realistic outdoor climatic conditions of Tlemcen city, Algeria. The numerical results showed that by using PCM in wall as energy storage components may reduce the room temperature by about 6 to 7°C of temperature depending on the floor level (first floor spaces or ground floor spaces.

  10. Seasonal thermal energy storage

    Science.gov (United States)

    Allen, R. D.; Kannberg, L. D.; Raymond, J. R.

    1984-05-01

    Seasonal thermal energy storage (STES) using heat or cold available from surplus, waste, climatic, or cogeneration sources show great promise to reduce peak demand, reduce electric utility load problems, and contribute to establishing favorable economics for district heating and cooling systems. Heated and chilled water can be injected, stored, and recovered from aquifers. Geologic materials are good thermal insulators, and potentially suitable aquifers are distributed throughout the United States. Potential energy sources for use in an aquifer thermal energy storage system include solar heat, power plant cogeneration, winter chill, and industrial waste heat source. Topics covered include: (1) the U.S. Department of Energy seasonal thermal energy storage program; (2) aquifer thermal energy storage technology; (3) alternative STES technology; (4) foreign studies in seasonal thermal energy storage; and (5) economic assessment.

  11. Thermal assessment of Shippingport pressurized water reactor blanket fuel assemblies within a multi-canister overpack within the canister storage building

    Energy Technology Data Exchange (ETDEWEB)

    HEARD, F.J.

    1999-04-09

    A series of analyses were performed to assess the thermal performance characteristics of the Shippingport Pressurized Water Reactor Core 2 Blanket Fuel Assemblies as loaded within a Multi-Canister Overpack within the Canister Storage Building. A two-dimensional finite element was developed, with enough detail to model the individual fuel plates: including the fuel wafers, cladding, and flow channels.

  12. Solar energy thermalization and storage device

    Science.gov (United States)

    McClelland, J.F.

    A passive solar thermalization and thermal energy storage assembly which is visually transparent is described. The assembly consists of two substantial parallel, transparent wall members mounted in a rectangular support frame to form a liquid-tight chamber. A semitransparent thermalization plate is located in the chamber, substantially paralled to and about equidistant from the transparent wall members to thermalize solar radiation which is stored in a transparent thermal energy storage liquid which fills the chamber. A number of the devices, as modules, can be stacked together to construct a visually transparent, thermal storage wall for passive solar-heated buildings.

  13. Energy flexibility of residential buildings using short term heat storage in the thermal mass

    DEFF Research Database (Denmark)

    Dreau, Jerome Le; Heiselberg, Per Kvols

    2016-01-01

    Highlights •Two residential buildings (80's and passive house) with two emitters (radiator, UH). •Different modulations of the set-point (upward/downward, duration, starting time). •Large differences between the 80s and the passive house, influence of the emitter. •Evaluation of the flexibility p...

  14. Effect of thermal energy storage in energy consumption required for air conditioning system in office building under the African Mediterranean climate

    Directory of Open Access Journals (Sweden)

    Abdulgalil Mohamed M.

    2014-01-01

    Full Text Available In the African Mediterranean countries, cooling demand constitutes a large proportion of total electrical demand for office buildings during peak hours. The thermal energy storage systems can be an alternative method to be utilized to reduce and time shift the electrical load of air conditioning from on-peak to off-peak hours. In this study, the Hourly Analysis Program has been used to estimate the cooling load profile for an office building based in Tripoli weather data conditions. Preliminary study was performed in order to define the most suitable operating strategies of ice thermal storage, including partial (load leveling and demand limiting, full storage and conventional A/C system. Then, the mathematical model of heat transfer for external ice storage would be based on the operating strategy which achieves the lowest energy consumption. Results indicate that the largest rate of energy consumption occurs when the conventional system is applied to the building, while the lowest rate of energy consumption is obtained when the partial storage (demand limiting 60% is applied. Analysis of results shows that the new layer of ice formed on the surface of the existing ice lead to an increase of thermal resistance of heat transfer, which in return decreased cooling capacity.

  15. Solar Thermal Storage System

    Directory of Open Access Journals (Sweden)

    Arjun A. Abhyankar

    2012-06-01

    Full Text Available Increasing energy consumption, shrinking resources and rising energy costs will have significant impact on our standard of living for future generations. In this situation, the development of alternative, cost effective sources of energy has to be a priority. This project presents the advanced technology and some of the unique features of a novel solar system that utilizes solar energy for space heating and water heating purpose in residential housing and commercial buildings. The improvements in solar technology offers a significant cost reduction, to a level where the solar system can compete with the energy costs from existing sources. The main goal of the project is to investigate new or advanced solutions for storing heat in systems providing heating. which can be achieved using phase change material(PCM.A phase change material with a melting/solidification temperature of 50ºC to 60ºC is used for solar heat storage. When the PCM undergoes the phase change, it can absorb or release a large amount of energy as latent heat. This heat can be used for further applications like water heating and space heating purposes. Thus solar thermal energy is widely use

  16. Applications and challenges for thermal energy storage

    Science.gov (United States)

    Kannberg, L. D.; Tomlinson, J. T.

    1991-04-01

    New thermal energy storage (TES) technologies are being developed and applied as society strives to relieve increasing energy and environmental stresses. Applications for these new technologies range from residential and district heating and cooling using waste and solar energy, to high-temperature energy storage for power production and industrial processes. In the last two decades there has been great interest and development of heat storage systems, primarily for residential and commercial buildings. While development has continued, the rate of advancement has slowed with current technology considered adequate for electrically charged heat storage furnaces. Use of chill storage for building diurnal cooling has received substantial development.

  17. Preliminary Study of Passive Cooling Strategy Using a Combination of PCM and Copper Foam to Increase Thermal Heat Storage in Building Facade

    Directory of Open Access Journals (Sweden)

    Hiroshi Yoshino

    2010-07-01

    Full Text Available The innovation of phase change material (PCM for thermal heat storage is one sustainable passive strategy that can be integrated into building designs. This research was conducted to study and evaluate the performance of the existing materials integrated with PCM and to propose a design strategy that would improve the system. This research suggested copper foam as a medium to be integrated with microencapsulated PCM. Applications of these combined materials will benefit the industry by improving indoor environments and by delivering sufficient thermal comfort for residents as in the case study of the existing 1.6 million terrace houses in Malaysia.

  18. Thermal energy storage program description

    Energy Technology Data Exchange (ETDEWEB)

    Reimers, E. [Dept. of Energy, Washington, DC (United States)

    1989-03-01

    The U.S. Department of Energy (DOE) has sponsored applied research, development, and demonstration of technologies aimed at reducing energy consumption and encouraging replacement of premium fuels (notably oil) with renewable or abundant indigenous fuels. One of the technologies identified as being able to contribute to these goals is thermal energy storage (TES). Based on the potential for TES to contribute to the historic mission of the DOE and to address emerging energy issues related to the environment, a program to develop specific TES technologies for diurnal, industrial, and seasonal applications is underway. Currently, the program is directed toward three major application targets: (1) TES development for efficient off-peak building heating and cooling, (2) development of advanced TES building materials, and (3) TES development to reduce industrial energy consumption.

  19. Thermal energy storage test facility

    Science.gov (United States)

    Ternes, M. P.

    1980-01-01

    The thermal behavior of prototype thermal energy storage units (TES) in both heating and cooling modes is determined. Improved and advanced storage systems are developed and performance standards are proposed. The design and construction of a thermal cycling facility for determining the thermal behavior of full scale TES units is described. The facility has the capability for testing with both liquid and air heat transport, at variable heat input/extraction rates, over a temperature range of 0 to 280 F.

  20. The Role of Energy Storage in Commercial Building

    Energy Technology Data Exchange (ETDEWEB)

    Kintner-Meyer, Michael CW; Subbarao, Krishnappa; Prakash Kumar, Nirupama; Bandyopadhyay, Gopal K.; Finley, C.; Koritarov, V. S.; Molburg, J. C.; Wang, J.; Zhao, Fuli; Brackney, L.; Florita, A. R.

    2010-09-30

    Motivation and Background of Study This project was motivated by the need to understand the full value of energy storage (thermal and electric energy storage) in commercial buildings, the opportunity of benefits for building operations and the potential interactions between a building and a smart grid infrastructure. On-site or local energy storage systems are not new to the commercial building sector; they have been in place in US buildings for decades. Most building-scale storage technologies are based on thermal or electrochemical storage mechanisms. Energy storage technologies are not designed to conserve energy, and losses associated with energy conversion are inevitable. Instead, storage provides flexibility to manage load in a building or to balance load and generation in the power grid. From the building owner's perspective, storage enables load shifting to optimize energy costs while maintaining comfort. From a grid operations perspective, building storage at scale could provide additional flexibility to grid operators in managing the generation variability from intermittent renewable energy resources (wind and solar). To characterize the set of benefits, technical opportunities and challenges, and potential economic values of storage in a commercial building from both the building operation's and the grid operation's view-points is the key point of this project. The research effort was initiated in early 2010 involving Argonne National Laboratory (ANL), the National Renewable Energy Laboratory (NREL), and Pacific Northwest National Laboratory (PNNL) to quantify these opportunities from a commercial buildings perspective. This report summarizes the early discussions, literature reviews, stakeholder engagements, and initial results of analyses related to the overall role of energy storage in commercial buildings. Beyond the summary of roughly eight months of effort by the laboratories, the report attempts to substantiate the importance of

  1. Results and experience of an aquifer thermal energy storage for heating and cooling of an office building and a demonstration center

    Energy Technology Data Exchange (ETDEWEB)

    Bael, Johan van; Desmedt, Johan; Vanhoudt, Dirk [Vlaamse Instelling voor Technologisch Onderzoek (VITO), Mol (Belgium)

    2010-07-01

    Aquifer Thermal Energy Storage (ATES) was introduced in the Belgian market since 1995. Until now over 10 installations with a thermal power of more than 300 kW cooling are installed. One of the first projects consists of the integration of ATES with a nominal power of 570 kWh in an existing office building and a new built demonstration center (3,000 m{sup 2}) for new lighting systems. The ATES system exists of a doublet: a cold and a warm well. The groundwater flow between the wells amounts to 90 m{sup 3}/h in the cooling modus and 45 m{sup 3}/h in the heating modus. The ATES system delivers the complete cooling demand of both buildings and a part of the heating demand. A gas fired boiler delivers the remaining heat demand. The project was funded by the Flemish Government in the Program of the Flemish Energy Demonstration Projects. The research institute VITO monitored the project during an evaluation period of three years. The energy flows (cooling and heating delivered to both buildings), the groundwater flow, the groundwater temperatures, the electricity consumption of the ATES and the gas consumption of the boiler were measured and stored every 30 minutes. This paper provides an overview of the monitoring results. (orig.)

  2. Optimizing Ice Thermal Storage to Reduce Energy Cost

    Science.gov (United States)

    Hall, Christopher L.

    Energy cost for buildings is an issue of concern for owners across the U.S. The bigger the building, the greater the concern. A part of this is due to the energy required to cool the building and the way in which charges are set when paying for energy consumed during different times of the day. This study will prove that designing ice thermal storage properly will minimize energy cost in buildings. The effectiveness of ice thermal storage as a means to reduce energy costs lies within transferring the time of most energy consumption from on-peak to off-peak periods. Multiple variables go into the equation of finding the optimal use of ice thermal storage and they are all judged with the final objective of minimizing monthly energy costs. This research discusses the optimal design of ice thermal storage and its impact on energy consumption, energy demand, and the total energy cost. A tool for optimal design of ice thermal storage is developed, considering variables such as chiller and ice storage sizes and charging and discharge times. The simulations take place in a four-story building and investigate the potential of Ice Thermal Storage as a resource in reducing and minimizing energy cost for cooling. The simulations test the effectiveness of Ice Thermal Storage implemented into the four-story building in ten locations across the United States.

  3. Increased use of solar energy in commercial buildings by integrating energy storage.

    OpenAIRE

    Nilsson, Nina

    2016-01-01

    From a comparison of available thermal energy storage (TES) technologies it can be concluded that the most mature and suitable storage methods for modern commercial buildings in Sweden are storage tanks, either for heat or cold energy, and underground storage solutions such as borehole thermal energy storage (BTES), aquifer storage and energy piles. In this study an integrated solar energy storage system for heating purpose has been designed with BTES, hot water storage tank(s) and solar ther...

  4. Thermal storage heaters

    Energy Technology Data Exchange (ETDEWEB)

    Stokes, K.H.; Broadbent, J.T.

    1991-02-27

    A storage heater, providing heat by radiation, comprises an internal circuit for the passage of heated air. The heater comprises: a heat storage core, comprising heat storage rods heated by resistance wiring, and an air space around the rods, the air space forming an inner pathway of circuit; heat insulation around the core; and outer pathways adjacent outer walls of the heater. A damper is arranged at the top of the inner and outer pathways to control the communication between. The damper may be movably supported on a support part by robust bi-metallic strips wound with heater wires to control the bending of the strips. The storage heater may be supplied in kit form for the purchaser to assemble and to this end the heat storage rods may comprise particulate material poured into tubes, or liftable core units. Further heat insulation may be selectively positioned in the outer pathways to provide an even heat distribution. (author).

  5. Thermal energy storage test facility

    Science.gov (United States)

    Ternes, M. P.

    1981-03-01

    Two loops making up the facility, using either air or liquid as the thermal transport fluid, are described. These loops will be capable of cycling residential-size thermal energy storage units through conditions simulating solar or off-peak electricity applications to evaluate the unit's performance. Construction of the liquid cycling loop was completed, and testing of thermal stratification techniques for hot and cold water is reported.

  6. Performance analysis of a soil-based thermal energy storage system using solar-driven air-source heat pump for Danish buildings sector

    DEFF Research Database (Denmark)

    Jradi, M.; Veje, C.; Jørgensen, B. N.

    2017-01-01

    source. Employing a PV system of 30 kW capacity, it was found that a storage medium of 900 m3 of soil is capable of providing the heating needs for a housing project of 1000 m2 internal floor area. The year round transient behaviour of the thermal energy storage medium is reported in addition to the heat...... and evaluation of the performance of an underground soil-based thermal energy storage system for solar energy storage, coupled with a combined heat and power generation system. A combined PV-Air Source Heat Pump (ASHP) system is utilized to fulfil heating and electricity needs of a housing project in Odense.......2% for the combined PV-ASHP system employing a seasonal underground thermal energy storage block....

  7. Thermal energy storage devices, systems, and thermal energy storage device monitoring methods

    Science.gov (United States)

    Tugurlan, Maria; Tuffner, Francis K; Chassin, David P.

    2016-09-13

    Thermal energy storage devices, systems, and thermal energy storage device monitoring methods are described. According to one aspect, a thermal energy storage device includes a reservoir configured to hold a thermal energy storage medium, a temperature control system configured to adjust a temperature of the thermal energy storage medium, and a state observation system configured to provide information regarding an energy state of the thermal energy storage device at a plurality of different moments in time.

  8. Thermal energy storage testing facility

    Science.gov (United States)

    Schoenhals, R. J.; Lin, C. P.; Kuehlert, H. F.; Anderson, S. H.

    1981-03-01

    Development of a prototype testing facility for performance evaluation of electrically heated thermal energy storage units is described. Laboratory apparatus and test procedures were evaluated by means of measurements and analysis. A 30kW central unit and several smaller individual room-size units were tested.

  9. Thermal energy storage testing facilities

    Science.gov (United States)

    Schoenhals, R. J.; Anderson, S. H.; Stevens, L. W.; Laster, W. R.; Elter, M. R.

    Development of a prototype testing facility for performance evaluation of electrically heated thermal energy storage units is discussed. Laboratory apparatus and test procedures are being evaluated by means of measurements and analysis. Testing procedures were improved, and test results were acquired for commercially available units. A 30 kW central unit and several smaller individual room-size units were tested.

  10. Thermal analysis and design of passive solar buildings

    CERN Document Server

    Athienitis, AK

    2013-01-01

    Passive solar design techniques are becoming increasingly important in building design. This design reference book takes the building engineer or physicist step-by-step through the thermal analysis and design of passive solar buildings. In particular it emphasises two important topics: the maximum utilization of available solar energy and thermal storage, and the sizing of an appropriate auxiliary heating/cooling system in conjunction with good thermal control.Thermal Analysis and Design of Passive Solar Buildings is an important contribution towards the optimization of buildings as systems th

  11. Passive hygrothermal control of a museum storage building in Vejle

    DEFF Research Database (Denmark)

    Christensen, Jørgen Erik; Janssen, Hans

    2010-01-01

    and maintenance costs are currently motivating a paradigm change toward passive control. Passive control, via the thermal and hygric inertia of the building, is gaining a foothold in the museum conservation and building physical community. In this report we document the hygrothermal performance optimisation...... of a museum storage building, related to an existing storage centre in Vejle (Denmark). The current building design already incorporates passive control concepts: thermal inertia is provided by the thick walls, the ground floor and its underlying soil volume, while hygric inertia is provided by the thick...... purposes. Reduction of dehumidification load: In an effort to reduce the necessary dehumidification, a number of thermal measures are investigated first. This primarily focuses on the influences of additional insulation in walls, roof and floor. Overall, the effects of extra insulation on the average...

  12. Aquifer thermal energy storage. International symposium: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    Aquifers have been used to store large quantities of thermal energy to supply process cooling, space cooling, space heating, and ventilation air preheating, and can be used with or without heat pumps. Aquifers are used as energy sinks and sources when supply and demand for energy do not coincide. Aquifer thermal energy storage may be used on a short-term or long-term basis; as the sole source of energy or as a partial storage; at a temperature useful for direct application or needing upgrade. The sources of energy used for aquifer storage are ambient air, usually cold winter air; waste or by-product energy; and renewable energy such as solar. The present technical, financial and environmental status of ATES is promising. Numerous projects are operating and under development in several countries. These projects are listed and results from Canada and elsewhere are used to illustrate the present status of ATES. Technical obstacles have been addressed and have largely been overcome. Cold storage in aquifers can be seen as a standard design option in the near future as it presently is in some countries. The cost-effectiveness of aquifer thermal energy storage is based on the capital cost avoidance of conventional chilling equipment and energy savings. ATES is one of many developments in energy efficient building technology and its success depends on relating it to important building market and environmental trends. This paper attempts to provide guidance for the future implementation of ATES. Individual projects have been processed separately for entry onto the Department of Energy databases.

  13. Electric thermal storage demonstration program

    Energy Technology Data Exchange (ETDEWEB)

    1992-02-01

    In early 1989, MMWEC, a joint action agency comprised of 30 municipal light departments in Massachusetts and on affiliate in Rhode Island, responded to a DOE request to proposal for the Least Cost Utility Planning program. The MMWEC submission was for the development of a program, focused on small rural electric utilities, to promote the use of electric thermal storage heating systems in residential applications. This report discusses the demonstration of ETS equipment at four member light departments.

  14. Electric thermal storage demonstration program

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    In early 1989, MMWEC, a joint action agency comprised of 30 municipal light departments in Massachusetts and on affiliate in Rhode Island, responded to a DOE request to proposal for the Least Cost Utility Planning program. The MMWEC submission was for the development of a program, focused on small rural electric utilities, to promote the use of electric thermal storage heating systems in residential applications. This report discusses the demonstration of ETS equipment at four member light departments.

  15. Thermal calculations for the study of the heat evacuation in the vaults building of the centralised temporary storage (ATC); Calculos termicos para el estudio de la evacuacion de calor en el Edificio de Bovedas del Almacen Temporal Centralizado (ATC)

    Energy Technology Data Exchange (ETDEWEB)

    Perez Dominguez, J. R.; Garcia Gonzalez, M.; Huelamo, E.

    2015-07-01

    This article presents the thermal analyses of the vaults building at the future Spanish Nuclear Waste Storage facility (ATC) in which spent nuclear fuel and high activity nuclear wastes are to be stored efficiency, safety and securely. the analyses have been carried out by means of computational fluid dynamics (CFD) simulation codes, for the purpose of confirming the adequate design of the storage buildings and in order to obtain the air flow rate required to guarantee that the different thermal criteria are met. The design relies on natural convection in order to remove residual heat from the nuclear waste. The simulation model allows the designer to perform sensitivity analyses to evaluate the impact of different design parameters, to optimize the heat load per fuel canister and to provide an optimal loading plan for the facility. (Author)

  16. Seasonal sensible thermal energy storage solutions

    Directory of Open Access Journals (Sweden)

    Lavinia Gabriela SOCACIU

    2012-08-01

    Full Text Available The thermal energy storage can be defined as the temporary storage of thermal energy at high or low temperatures. Thermal energy storage is an advances technology for storing thermal energy that can mitigate environmental impacts and facilitate more efficient and clean energy systems. Seasonal thermal energy storage has a longer thermal storage period, generally three or more months. This can contribute significantly to meeting society`s need for heating and cooling. The objectives of thermal energy storage systems are to store solar heat collected in summer for space heating in winter. This concept is not new; it is been used and developed for centuries because is playing an important role in energy conservation and contribute significantly to improving the energy efficiency and reducing the gas emissions to the atmosphere.

  17. Solar Air Heaters with Thermal Heat Storages

    Directory of Open Access Journals (Sweden)

    Abhishek Saxena

    2013-01-01

    Full Text Available Solar energy can be converted into different forms of energy, either to thermal energy or to electrical energy. Solar energy is converted directly into electrical power by photovoltaic modules, while solar collector converts solar energy into thermal energy. Solar collector works by absorbing the direct solar radiation and converting it into thermal energy, which can be stored in the form of sensible heat or latent heat or a combination of sensible and latent heats. A theoretical study has been carried out to rate the various thermal energy storage commonly used in solar air heaters. During the investigations rock bed storages have been found to be low type thermal heat storage, while phase change materials have been found to be high heat thermal storages. Besides this, a few other heat storing materials have been studied and discussed for lower to higher ratings in terms of thermal performance purposely for solar heaters.

  18. Thermal energy storage apparatus, controllers and thermal energy storage control methods

    Science.gov (United States)

    Hammerstrom, Donald J.

    2016-05-03

    Thermal energy storage apparatus, controllers and thermal energy storage control methods are described. According to one aspect, a thermal energy storage apparatus controller includes processing circuitry configured to access first information which is indicative of surpluses and deficiencies of electrical energy upon an electrical power system at a plurality of moments in time, access second information which is indicative of temperature of a thermal energy storage medium at a plurality of moments in time, and use the first and second information to control an amount of electrical energy which is utilized by a heating element to heat the thermal energy storage medium at a plurality of moments in time.

  19. Environmental Control Unit with Integral Thermal Storage

    Science.gov (United States)

    2014-06-12

    integrated PCM Heat Exchanger (PHX) to provide thermal energy storage. By storing thermal energy during the hottest part of the day and rejecting this stored...Environmental Control Unit (ECU) that uses an integrated PCM Heat Exchanger (PHX) to provide thermal energy storage. To aid in the development of the PHX... Thermal Storage 5a. CONTRACT NUMBER W911QX-14-C-0014 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Michael C. Ellis Ryan McDevitt 5d

  20. Thermal performance and heat transport in aquifer thermal energy storage

    NARCIS (Netherlands)

    Sommer, W.T.; Doornenbal, P.J.; Drijver, B.C.; Gaans, van P.F.M.; Leusbrock, I.; Grotenhuis, J.T.C.; Rijnaarts, H.H.M.

    2014-01-01

    Aquifer thermal energy storage (ATES) is used for seasonal storage of large quantities of thermal energy. Due to the increasing demand for sustainable energy, the number of ATES systems has increased rapidly, which has raised questions on the effect of ATES systems on their surroundings as well as t

  1. Technical and economic feasibility of thermal storage. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Shelpuk, B.; Joy, P.; Crouthamel, M.

    1977-06-01

    The technical and economic feasibility of various thermal energy storage alternatives is determined by comparing the system performance and annualized cost which result from each storage alternative operating with the same solar collector model, the same building load model, and the same heating system and controls model. Performance and cost calculations are made on the basis of an hour-by-hour time step using actual weather bureau data for Albuquerque, N. M., and New York City for a single six-month heating season. The primary approach to comparing various storage alternatives is to allow the collector area and storage mass to vary until a minimum cost combination is achieved. In the Albuquerque location collector area of 325 ft/sup 2/, water storage mass of 12.5 lb/ft/sup 2/ of collector area, and phase change mass of 6.25 lb/ft/sup 2/ of collector area results in minimum cost systems, each of which delivers about 50% of the total building demand. The primary conclusion is that, using current costs for materials and containers, water is the cheapest storage alternative for heating applications in both Albuquerque and New York City. The cost of containing or encapsulating phase change materials, coupled with their small system performance advantage, is the main reason for this conclusion. The use of desiccant materials for thermal storage is considered to be impractical due to irreversibilities in thermal cycling.

  2. 2401-W Waste storage building closure plan

    Energy Technology Data Exchange (ETDEWEB)

    LUKE, S.M.

    1999-07-15

    This plan describes the performance standards met and closure activities conducted to achieve clean closure of the 2401-W Waste Storage Building (2401-W) (Figure I). In August 1998, after the last waste container was removed from 2401-W, the U.S. Department of Energy, Richland Operations Office (DOE-RL) notified Washington State Department of Ecology (Ecology) in writing that the 2401-W would no longer receive waste and would be closed as a Resource Conservation and Recovery Act (RCRA) of 1976 treatment, storage, and/or disposal (TSD) unit (98-EAP-475). Pursuant to this notification, closure activities were conducted, as described in this plan, in accordance with Washington Administrative Code (WAC) 173-303-610 and completed on February 9, 1999. Ecology witnessed the closure activities. Consistent with clean closure, no postclosure activities will be necessary. Because 2401-W is a portion of the Central Waste Complex (CWC), these closure activities become the basis for removing this building from the CWC TSD unit boundary. The 2401-W is a pre-engineered steel building with a sealed concrete floor and a 15.2-centimeter concrete curb around the perimeter of the floor. This building operated from April 1988 until August 1998 storing non-liquid containerized mixed waste. All waste storage occurred indoors. No potential existed for 2401-W operations to have impacted soil. A review of operating records and interviews with cognizant operations personnel indicated that no waste spills occurred in this building (Appendix A). After all waste containers were removed, a radiation survey of the 2401-W floor for radiological release of the building was performed December 17, 1998, which identified no radiological contamination (Appendix B).

  3. Pemakaian Thermal Storage pada Sistem Pengkondisi Udara

    Directory of Open Access Journals (Sweden)

    Herry Sunandar

    1999-01-01

    Full Text Available Air conditioning system consume 70 - 80 % of a building's energy requirement. Application of ice storage system can regulate electric load consumption so that its peak load can be controlled. Abstract in Bahasa Indonesia : Sistem pengkondisian udara memakai energi 70 - 80 % dari seluruh energy sebuah gedung. Penerapan ice storage pada sistem tersebut dapat mengatur pemakaian beban listrik sehingga pemakaian beban listrik pada beban puncak dapat dikontrol. Kata kunci : ice storage, chiller, sistem pengkondisi udara

  4. Lightweight Thermal Storage Heat Exchangers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR proposal aims to develop thermal energy storage heat exchangers that are significantly lighter and higher conductance than the present art which involves...

  5. Canister storage building hazard analysis report

    Energy Technology Data Exchange (ETDEWEB)

    Krahn, D.E.; Garvin, L.J.

    1997-07-01

    This report describes the methodology used in conducting the Canister Storage Building (CSB) hazard analysis to support the final CSB safety analysis report (SAR) and documents the results. The hazard analysis was performed in accordance with DOE-STD-3009-94, Preparation Guide for US Department of Energy Nonreactor Nuclear Facility Safety Analysis Report, and implements the requirements of DOE Order 5480.23, Nuclear Safety Analysis Report.

  6. Modeling energy flexibility of low energy buildings utilizing thermal mass

    DEFF Research Database (Denmark)

    Foteinaki, Kyriaki; Heller, Alfred; Rode, Carsten

    2016-01-01

    the load shifting potential of an apartment of a low energy building in Copenhagen is assessed, utilizing the heat storage capacity of the thermal mass when the heating system is switched off for relieving the energy system. It is shown that when using a 4-hour preheating period before switching off...... of the external envelope and the thermal capacity of the internal walls as the main parameters that affect the load shifting potential of the apartment....... to match the production patterns, shifting demand from on-peak hours to off-peak hours. Buildings could act as flexibility suppliers to the energy system, through load shifting potential, provided that the large thermal mass of the building stock could be utilized for energy storage. In the present study...

  7. Optimization and spatial pattern of large-scale aquifer thermal energy storage

    NARCIS (Netherlands)

    Sommer, W.T.; Valstar, J.; Leusbrock, I.; Grotenhuis, J.T.C.; Rijnaarts, H.H.M.

    2015-01-01

    Aquifer thermal energy storage (ATES) is a cost-effective technology that enables the reduction of energy use and CO2 emissions associated with the heating and cooling of buildings by storage and recovery of large quantities of thermal energy in the subsurface. Reducing the distance between wells in

  8. Canister storage building hazard analysis report

    Energy Technology Data Exchange (ETDEWEB)

    POWERS, T.B.

    1999-05-11

    This report describes the methodology used in conducting the Canister Storage Building (CSB) hazard analysis to support the CSB final safety analysis report (FSAR) and documents the results. The hazard analysis was performed in accordance with the DOE-STD-3009-94, ''Preparation Guide for US. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports'', and meets the intent of HNF-PRO-704, ''Hazard and Accident Analysis Process''. This hazard analysis implements the requirements of DOE Order 5480.23, ''Nuclear Safety Analysis Reports''.

  9. Thermal energy storage technical progress report, April 1992--March 1993

    Energy Technology Data Exchange (ETDEWEB)

    Olszewski, M.

    1993-05-01

    The Department of Energy (DOE) is supporting development of thermal energy storage (TES) as a means of efficiently coupling energy supplies to variable heating or cooling demands. Uses of TES include electrical demand-side management in buildings and industry, extending the utilization of renewable energy resources such as solar, and recovery of waste heat from periodic industrial processes. Technical progress to develop TES for specific diurnal and industrial applications under the Oak Ridge National Laboratory`s TES program from April 1992 to March 1993 is reported and covers research in the areas of low temperature sorption, thermal energy storage water heater, latent heat storage wallboard and latent/sensible heat regenerator technology development.

  10. Aquifer thermal energy (heat and chill) storage

    Energy Technology Data Exchange (ETDEWEB)

    Jenne, E.A. (ed.)

    1992-11-01

    As part of the 1992 Intersociety Conversion Engineering Conference, held in San Diego, California, August 3--7, 1992, the Seasonal Thermal Energy Storage Program coordinated five sessions dealing specifically with aquifer thermal energy storage technologies (ATES). Researchers from Sweden, The Netherlands, Germany, Switzerland, Denmark, Canada, and the United States presented papers on a variety of ATES related topics. With special permission from the Society of Automotive Engineers, host society for the 1992 IECEC, these papers are being republished here as a standalone summary of ATES technology status. Individual papers are indexed separately.

  11. Thermal performance of a PCM thermal storage unit

    Energy Technology Data Exchange (ETDEWEB)

    Liu Ming; Bruno, Frank; Saman, Wasim [Sustainable Energy Centre, Inst. for Sustainable Systems and Technologies, Univ. of South Australia, Mawson Lakes, Adelaide (Australia)

    2008-07-01

    The thermal performance of a PCM thermal storage unit (TSU) is studied numerically and experimentally. The TSU under analysis consists of several flat slabs of phase change material (PCM) with melting temperature of -26.7 C. Liquid heat transfer fluid (HTF) passes between the slabs to charge and discharge the storage unit. A one dimensional mathematical model was employed to analyze the transient thermal behavior of the storage unit during the melting and freezing processes. The model takes into consideration the temperature variations in the wall along the flow direction of the HTF. The paper compares the experimental and numerical simulation results in terms of HTF outlet temperatures during the melting period. (orig.)

  12. Thermal testing of building envelopes

    Science.gov (United States)

    Lebedev, O.; Kirzhanov, D.; Avramenko, V.; Budadin, O.

    2006-04-01

    Averaged heat transfer resistance of the building envelope is the primary parameter that determines the energy saving characteristics of the building. At the phase of the building design it is usually taken into account that building must preserve heat effectively. It is mostly important in northern countries where cold seasons last for more than a half of year. Usually infrared methods are used to find mechanical defects of the building envelope. In this article an alternative way to describe the building envelope using infrared camera is presented. The method includes the determination of local heat engineering characteristics of the envelope using contact measurements and the determination of averaged heat transfer resistance of the buildings envelope using its infrared image.

  13. Biogeochemical aspects of aquifer thermal energy storage.

    NARCIS (Netherlands)

    Brons, H.J.

    1992-01-01

    During the process of aquifer thermal energy storage the in situ temperature of the groundwater- sediment system may fluctuate significantly. As a result the groundwater characteristics can be considerably affected by a variety of chemical, biogeochemical and microbiological reactions. The inter

  14. Microencapsulated PCM thermal-energy storage system

    Energy Technology Data Exchange (ETDEWEB)

    Hawlader, M.N.A.; Uddin, M.S. [National Univ. of Singapore, Dept. of Chemical and Environmental Engineering, Singapore (Singapore); Khin, Mya Mya [National Univ. of Singapore, Dept. of Mechanical Engineering, Singapore (Singapore)

    2003-02-01

    The application of phase-change materials (PCM) for solar thermal-energy storage capacities has received considerable attention in recent years due to their large storage capacity and isothermal nature of the storage process. This study deals with the preparation and characterization of encapsulated paraffin-wax. Encapsulated paraffin particles were prepared by complex coacervation as well as spray-drying methods. The influence of different parameters on the characteristics and performance of a microencapsulated PCM in terms of encapsulation efficiency, and energy storage and release capacity has been investigated. The distribution of particle size and the morphology of microencapsulated PCM were analyzed by a scanning electron microscope (SEM). In the coacervation method, the optimum homogenizing time is 10 min and the amount of cross-linking agent is 6-8 mI. Results obtained from a differential scanning calorimeter (DSC) show that microcapsules prepared either by coacervation or the spray-drying method have a thermal energy storage/release capacity of about 145-240 J/g. Hence, encapsulated paraffin wax shows a good potential as a solar-energy storage material. (Author)

  15. Design and installation manual for thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Cole, R L; Nield, K J; Rohde, R R; Wolosewicz, R M

    1980-01-01

    The purpose of this manual is to provide information on the design and installation of thermal energy storage in active solar systems. It is intended for contractors, installers, solar system designers, engineers, architects, and manufacturers who intend to enter the solar energy business. The reader should have general knowledge of how solar heating and cooling systems operate and knowledge of construction methods and building codes. Knowledge of solar analysis methods such as f-Chart, SOLCOST, DOE-1, or TRNSYS would be helpful. The information contained in the manual includes sizing storage, choosing a location for the storage device, and insulation requirements. Both air-based and liquid-based systems are covered with topics on designing rock beds, tank types, pump and fan selection, installation, costs, and operation and maintenance. Topics relevant to latent heat storage include properties of phase-change materials, sizing the storage unit, insulating the storage unit, available systems, and cost. Topics relevant to heating domestic water include safety, single- and dual-tank systems, domestic water heating with air- and liquid-based space heating systems, and stand alone domestics hot water systems. Several appendices present common problems with storage systems and their solutions, heat transfer fluid properties, economic insulation thickness, heat exchanger sizing, and sample specifications for heat exchangers, wooden rock bins, steel tanks, concrete tanks, and fiberglass-reinforced plastic tanks.

  16. Canister storage building design basis accident analysis documentation

    Energy Technology Data Exchange (ETDEWEB)

    KOPELIC, S.D.

    1999-02-25

    This document provides the detailed accident analysis to support HNF-3553, Spent Nuclear Fuel Project Final Safety Analysis Report, Annex A, ''Canister Storage Building Final Safety Analysis Report.'' All assumptions, parameters, and models used to provide the analysis of the design basis accidents are documented to support the conclusions in the Canister Storage Building Final Safety Analysis Report.

  17. Canister Storage Building (CSB) Design Basis Accident Analysis Documentation

    Energy Technology Data Exchange (ETDEWEB)

    CROWE, R.D.; PIEPHO, M.G.

    2000-03-23

    This document provided the detailed accident analysis to support HNF-3553, Spent Nuclear Fuel Project Final Safety Analysis Report, Annex A, ''Canister Storage Building Final Safety Analysis Report''. All assumptions, parameters, and models used to provide the analysis of the design basis accidents are documented to support the conclusions in the Canister Storage Building Final Safety Analysis Report.

  18. Investigation of floor heating with thermal storage

    Institute of Scientific and Technical Information of China (English)

    LIN Zhen-guo; ZHANG Su-yun; FU Xiang-zhao; WANG Yong

    2006-01-01

    Based on experimental data, the energy storage performances of floor radiant heating system were investigated.Based on experimental data, the energy storage performances of floor radiant heating system were investigated. The decrease of indoor air temperature after the stopping of floor heating was compared with that of fan-coil heating system. The increase of indoor air temperature after the stopping of floor cooling system was analyzed. The results show that the floor heating system has good thermal storage performance, which can be used to a night-running model to obtain the energy-saving benefits efficient and economic running cost, and still can be used for "shifting peak load to off-peak" macroscopically.

  19. Smart Building: Decision Making Architecture for Thermal Energy Management.

    Science.gov (United States)

    Uribe, Oscar Hernández; Martin, Juan Pablo San; Garcia-Alegre, María C; Santos, Matilde; Guinea, Domingo

    2015-10-30

    Smart applications of the Internet of Things are improving the performance of buildings, reducing energy demand. Local and smart networks, soft computing methodologies, machine intelligence algorithms and pervasive sensors are some of the basics of energy optimization strategies developed for the benefit of environmental sustainability and user comfort. This work presents a distributed sensor-processor-communication decision-making architecture to improve the acquisition, storage and transfer of thermal energy in buildings. The developed system is implemented in a near Zero-Energy Building (nZEB) prototype equipped with a built-in thermal solar collector, where optical properties are analysed; a low enthalpy geothermal accumulation system, segmented in different temperature zones; and an envelope that includes a dynamic thermal barrier. An intelligent control of this dynamic thermal barrier is applied to reduce the thermal energy demand (heating and cooling) caused by daily and seasonal weather variations. Simulations and experimental results are presented to highlight the nZEB thermal energy reduction.

  20. Smart Building: Decision Making Architecture for Thermal Energy Management

    Directory of Open Access Journals (Sweden)

    Oscar Hernández Uribe

    2015-10-01

    Full Text Available Smart applications of the Internet of Things are improving the performance of buildings, reducing energy demand. Local and smart networks, soft computing methodologies, machine intelligence algorithms and pervasive sensors are some of the basics of energy optimization strategies developed for the benefit of environmental sustainability and user comfort. This work presents a distributed sensor-processor-communication decision-making architecture to improve the acquisition, storage and transfer of thermal energy in buildings. The developed system is implemented in a near Zero-Energy Building (nZEB prototype equipped with a built-in thermal solar collector, where optical properties are analysed; a low enthalpy geothermal accumulation system, segmented in different temperature zones; and an envelope that includes a dynamic thermal barrier. An intelligent control of this dynamic thermal barrier is applied to reduce the thermal energy demand (heating and cooling caused by daily and seasonal weather variations. Simulations and experimental results are presented to highlight the nZEB thermal energy reduction.

  1. Smart Building: Decision Making Architecture for Thermal Energy Management

    Science.gov (United States)

    Hernández Uribe, Oscar; San Martin, Juan Pablo; Garcia-Alegre, María C.; Santos, Matilde; Guinea, Domingo

    2015-01-01

    Smart applications of the Internet of Things are improving the performance of buildings, reducing energy demand. Local and smart networks, soft computing methodologies, machine intelligence algorithms and pervasive sensors are some of the basics of energy optimization strategies developed for the benefit of environmental sustainability and user comfort. This work presents a distributed sensor-processor-communication decision-making architecture to improve the acquisition, storage and transfer of thermal energy in buildings. The developed system is implemented in a near Zero-Energy Building (nZEB) prototype equipped with a built-in thermal solar collector, where optical properties are analysed; a low enthalpy geothermal accumulation system, segmented in different temperature zones; and an envelope that includes a dynamic thermal barrier. An intelligent control of this dynamic thermal barrier is applied to reduce the thermal energy demand (heating and cooling) caused by daily and seasonal weather variations. Simulations and experimental results are presented to highlight the nZEB thermal energy reduction. PMID:26528978

  2. PHASE CHANGE MATERIALS IN FLOOR TILES FOR THERMAL ENERGY STORAGE

    Energy Technology Data Exchange (ETDEWEB)

    Douglas C. Hittle

    2002-10-01

    Passive solar systems integrated into residential structures significantly reduce heating energy consumption. Taking advantage of latent heat storage has further increased energy savings. This is accomplished by the incorporation of phase change materials into building materials used in passive applications. Trombe walls, ceilings and floors can all be enhanced with phase change materials. Increasing the thermal storage of floor tile by the addition of encapsulated paraffin wax is the proposed topic of research. Latent heat storage of a phase change material (PCM) is obtained during a change in phase. Typical materials use the latent heat released when the material changes from a liquid to a solid. Paraffin wax and salt hydrates are examples of such materials. Other PCMs that have been recently investigated undergo a phase transition from one solid form to another. During this process they will release heat. These are known as solid-state phase change materials. All have large latent heats, which makes them ideal for passive solar applications. Easy incorporation into various building materials is must for these materials. This proposal will address the advantages and disadvantages of using these materials in floor tile. Prototype tile will be made from a mixture of quartz, binder and phase change material. The thermal and structural properties of the prototype tiles will be tested fully. It is expected that with the addition of the phase change material the structural properties will be compromised to some extent. The ratio of phase change material in the tile will have to be varied to determine the best mixture to provide significant thermal storage, while maintaining structural properties that meet the industry standards for floor tile.

  3. Parametric Study on the Dynamic Heat Storage Capacity of Building Elements

    DEFF Research Database (Denmark)

    Artmann, Nikolai; Manz, H.; Heiselberg, Per

    2007-01-01

    as their interrelation. The potential of increasing thermal mass by using phase change materials (PCM) was estimated assuming increased thermal capacity. The results show a significant impact of the heat transfer coefficient on heat storage capacity, especially for thick, thermally heavy elements. The storage capacity...... of a 100 mm thick concrete slab was found to increase with increasing heat transfer coefficients as high as 30 W/m2K. In contrast the heat storage capacity of a thin gypsum plaster board was found to be constant when the heat transfer coefficient exceeded 3 W/m2K. Additionally, the optimal thickness...... potential. However, because heat gains and night ventilation periods do not coincide in time, a sufficient amount of thermal mass is needed in the building to store the heat. Assuming a 24 h-period harmonic oscillation of the indoor air temperature within a range of thermal comfort, the analytical solution...

  4. Thermal comfort assessment of buildings

    CERN Document Server

    Carlucci, Salvatore

    2013-01-01

    A number of metrics for assessing human thermal response to climatic conditions have been proposed in scientific literature over the last decades. They aim at describing human thermal perception of the thermal environment to which an individual or a group of people is exposed. More recently, a new type of “discomfort index” has been proposed for describing, in a synthetic way, long-term phenomena. Starting from a systematic review of a number of long-term global discomfort indices, they are then contrasted and compared on a reference case study in order to identify their similarities and differences and strengths and weaknesses. Based on this analysis, a new short-term local discomfort index is proposed for the American Adaptive comfort model. Finally, a new and reliable long-term general discomfort index is presented. It is delivered in three versions and each of them is suitable to be respectively coupled with the Fanger, the European Adaptive and the American Adaptive comfort models.

  5. Thermal Energy Storage with Phase Change Material

    Directory of Open Access Journals (Sweden)

    Lavinia Gabriela SOCACIU

    2012-08-01

    Full Text Available Thermal energy storage (TES systems provide several alternatives for efficient energy use and conservation. Phase change materials (PCMs for TES are materials supplying thermal regulation at particular phase change temperatures by absorbing and emitting the heat of the medium. TES in general and PCMs in particular, have been a main topic in research for the last 30 years, but although the information is quantitatively enormous, it is also spread widely in the literature, and difficult to find. PCMs absorb energy during the heating process as phase change takes place and release energy to the environment in the phase change range during a reverse cooling process. PCMs possesses the ability of latent thermal energy change their state with a certain temperature. PCMs for TES are generally solid-liquid phase change materials and therefore they need encapsulation. TES systems using PCMs as a storage medium offers advantages such as high TES capacity, small unit size and isothermal behaviour during charging and discharging when compared to the sensible TES.

  6. Evaluation of New Thermally Conductive Geopolymer in Thermal Energy Storage

    Science.gov (United States)

    Černý, Matěj; Uhlík, Jan; Nosek, Jaroslav; Lachman, Vladimír; Hladký, Radim; Franěk, Jan; Brož, Milan

    This paper describes an evaluation of a newly developed thermally conductive geopolymer (TCG), consisting of a mixture of sodium silicate and carbon micro-particles. The TCG is intended to be used as a component of high temperature energy storage (HTTES) to improve its thermal diffusivity. Energy storage is crucial for both ecological and economical sustainability. HTTES plays a vital role in solar energy technologies and in waste heat recovery. The most advanced HTTES technologies are based on phase change materials or molten salts, but suffer with economic and technological limitations. Rock or concrete HTTES are cheaper, but they have low thermal conductivity without incorporation of TCG. It was observed that TCG is stable up to 400 °C. The thermal conductivity was measured in range of 20-23 W m-1 K-1. The effect of TCG was tested by heating a granite block with an artificial fissure. One half of the fissure was filled with TCG and the other with ballotini. 28 thermometers, 5 dilatometers and strain sensors were installed on the block. The heat transport experiment was evaluated with COMSOL Multiphysics software.

  7. Thermal storage technologies for solar industrial process heat applications

    Science.gov (United States)

    Gordon, L. H.

    1979-01-01

    The state-of-the-art of thermal storage subsystems for the intermediate and high temperature (100 C to 600 C) solar industrial process heat generation is presented. Primary emphasis is focused on buffering and diurnal storage as well as total energy transport. In addition, advanced thermal storage concepts which appear promising for future solar industrial process heat applications are discussed.

  8. Development of space heating and domestic hot water systems with compact thermal energy storage. Compact thermal energy storage: Material development for System Integration

    NARCIS (Netherlands)

    Davidson, J.H.; Quinnell, J.; Burch, J.; Zondag, H.A.; Boer, R. de; Finck, C.J.; Cuypers, R.; Cabeza, L.F.; Heinz, A.; Jahnig, D.; Furbo, S.; Bertsch, F.

    2013-01-01

    Long-term, compact thermal energy storage (TES) is essential to the development of cost-effective solar and passive building-integrated space heating systems and may enhance the annual technical and economic performance of solar domestic hot water (DHW) systems. Systems should provide high energy st

  9. Low temperature thermal-energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Segaser, C.S.; Christian, J.E.

    1979-03-01

    This report evaluates currently available techniques and estimated costs of low temperature thermal energy storage (TES) devices applicable to Integrated Community Energy Systems (ICES) installations serving communities ranging in size from approximately 3000 (characterized by an electrical load requirement of 2 MWe) to about 100,000 population (characterized by an electrical load requirement of 100 MWe). Thermal energy in the form of either hotness or coldness can be stored in a variety of media as sensible heat by virtue of a change in temperature of the material, or as latent heat of fusion in which the material changes from the liquid phase to the solid phase at essentially a constant temperature. Both types of material are considered for TES in ICES applications.

  10. Spent nuclear fuel canister storage building conceptual design report

    Energy Technology Data Exchange (ETDEWEB)

    Swenson, C.E. [Westinghouse Hanford Co., Richland, WA (United States)

    1996-01-01

    This Conceptual Design Report provides the technical basis for the Spent Nuclear Fuels Project, Canister Storage Building, and as amended by letter (correspondence number 9555700, M.E. Witherspoon to E.B. Sellers, ``Technical Baseline and Updated Cost Estimate for the Canister Storage Building``, dated October 24, 1995), includes the project cost baseline and Criteria to be used as the basis for starting detailed design in fiscal year 1995.

  11. Canister Storage Building (CSB) Design Basis Accident Analysis Documentation

    Energy Technology Data Exchange (ETDEWEB)

    CROWE, R.D.

    1999-09-09

    This document provides the detailed accident analysis to support ''HNF-3553, Spent Nuclear Fuel Project Final Safety, Analysis Report, Annex A,'' ''Canister Storage Building Final Safety Analysis Report.'' All assumptions, parameters, and models used to provide the analysis of the design basis accidents are documented to support the conclusions in the Canister Storage Building Final Safety Analysis Report.

  12. Assessment of the technoeconomic feasibility or seasonal thermal energy storage systems (STES)

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

    The feasibility of the use of Seasonal Thermal Energy Storage (STES) systems employing large volumes of water is examined on the bases of technology and economics. Three building types are considered: single-family houses, low-rise multi-family apartment buildings, and small commercial buildings. Construction costs are based on prevailing conditions in the suburban Chicago area marketplace. Various types of vessels above and below ground are considered along with possible vessel materials. (MHR)

  13. PCM thermal insulation in buildings

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, K.A.R. [UNICAMP, Dept. de Engenharia Termica e Fluidos, Campinas, SP (Brazil); Castro, J.N.C. [UNESP, Dept. de Energia, Guaratingueta, SP (Brazil)

    1997-11-01

    This paper presents the results of a numerical and experimental study of phase change material (PCM) filled walls and roofs under real operational conditions to achieve passive thermal comfort. The numerical part of the study was based on a one-dimensional model for the phase change problem controlled by pure conduction. Real radiation data was used to determine the external face temperature. The numerical treatment was based upon using finite difference approximations and the ADI scheme. The results obtained were compared with field measurements. The experimental set-up consisted of a small room with movable roof and side wall. The roof was constructed in the traditional way but with the phase change material enclosed. Thermocouples were distributed across the cross section of the roof. Another roof, identical but without the PCM, was also used during comparative tests. The movable wall was also constructed as is done traditionally but with the PCM enclosed. Again, thermocouples were distributed across the wall thickness to enable measurement of the local temperatures. Another wall, identical but without the PCM, was also used during comparative tests. The PCM used in the numerical and experimental tests was composed of a mixture of two commercial grades of glycol in order to obtain the required fusion temperature range. Comparison between the simulation results and the experiments indicated good agreement. Field tests also indicated that the PCM used was adequate and that the concept was effective in maintaining the indoor temperature very close to the established comfort limits. Further economical analysis indicated that the concept could effectively help in reducing the electric energy consumption and improving the energy demand pattern. (Author)

  14. Commercialization of aquifer thermal energy storage technology

    Energy Technology Data Exchange (ETDEWEB)

    Hattrup, M.P.; Weijo, R.O.

    1989-09-01

    Pacific Northwest Laboratory (PNL) conducted this study for the US Department of Energy's (DOE) Office of Energy Storage and Distribution. The purpose of the study was to develop and screen a list of potential entry market applications for aquifer thermal energy storage (ATES). Several initial screening criteria were used to identify promising ATES applications. These include the existence of an energy availability/usage mismatch, the existence of many similar applications or commercial sites, the ability to utilize proven technology, the type of location, market characteristics, the size of and access to capital investment, and the number of decision makers involved. The in-depth analysis identified several additional screening criteria to consider in the selection of an entry market application. This analysis revealed that the best initial applications for ATES are those where reliability is acceptable, and relatively high temperatures are allowable. Although chill storage was the primary focus of this study, applications that are good candidates for heat ATES were also of special interest. 11 refs., 3 tabs.

  15. Design and installation manual for thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Cole, R L; Nield, K J; Rohde, R R; Wolosewicz, R M [eds.

    1979-02-01

    The purpose for this manual is to provide information on the design and installation of thermal energy storage in solar heating systems. It is intended for contractors, installers, solar system designers, engineers, architects, and manufacturers who intend to enter the solar energy business. The reader should have general knowledge of how solar heating systems operate and knowledge of construction methods and building codes. Knowledge of solar analysis methods such as f-chart, SOLCOST, DOE-1, or TRNSYS would be helpful. The information contained in the manual includes sizing storage, choosing a location for the storage device, and insulation requirements. Both air-based and liquid-based systems are covered with topics on designing rock beds, tank types, pump and fan selection, installation, costs, and operation and maintenance. Topics relevant to heating domestic water include safety, single- and dual-tank systems, domestic water heating with air- and liquid-based space heating system, and stand-alone domestic hot water systems. Several appendices present common problems with storage systems and their solutions, heat transfer fluid properties, heat exchanger sizing, and sample specifications for heat exchangers, wooden rock bins, steel tanks, concrete tanks, and fiberglass-reinforced plastic tanks.

  16. Building and managing high performance, scalable, commodity mass storage systems

    Science.gov (United States)

    Lekashman, John

    1998-01-01

    The NAS Systems Division has recently embarked on a significant new way of handling the mass storage problem. One of the basic goals of this new development are to build systems at very large capacity and high performance, yet have the advantages of commodity products. The central design philosophy is to build storage systems the way the Internet was built. Competitive, survivable, expandable, and wide open. The thrust of this paper is to describe the motivation for this effort, what we mean by commodity mass storage, what the implications are for a facility that performs such an action, and where we think it will lead.

  17. Air quality in low-ventilated museum storage buildings

    DEFF Research Database (Denmark)

    Ryhl-Svendsen, Morten; Aasbjerg Jensen, Lars; Klenz Larsen, Poul

    2014-01-01

    Modern low-energy museum storage buildings are often designed for a low air exchange rate, on the order of less than 1 exchange per day. We investigated how this affected the indoor air quality in six Danish museum storage buildings. The infiltration of ambient pollutants, and the level to which...... internally-generated pollutants accumulate, were measured by passive sampling of ozone, nitrogen dioxide, and organic acids. The air exchange rates and the interchange of air between storage rooms were measured by the per-fluorocarbon tracer gas method. Ambient pollutants were reduced in concentration...

  18. Economics of compressed air energy storage employing thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, S.C.; Reilly, R.W.

    1979-11-01

    The approach taken in this study is to adopt system design and capital cost estimates from three independent CAES studies (eight total designs) and, by supplying a common set of fuel/energy costs and economic assumptions in conjunction with a common methodology, to arrive at a series of levelized energy costs over the system's lifetime. In addition, some analyses are provided to gauge the sensitivity of these levelized energy costs to fuel and compression energy costs and to system capacity factors. The systems chosen for comparison are of four generic types: conventional CAES, hybrid CAES, adiabatic CAES, and an advanced-design gas turbine (GT). In conventional CAES systems the heat of compression generated during the storage operation is rejected to the environment, and later, during the energy-generation phase, turbine fuel must be burned to reheat the compressed air. In the hybrid systems some of the heat of compression is stored and reapplied later during the generation phase, thereby reducing turbine fuel requirements. The adiabatic systems store adequate thermal energy to eliminate the need for turbine fuel entirely. The gas turbine is included within the report for comparison purposes; it is an advanced-design turbine, one that is expected to be available by 1985.

  19. Storage phosphors for thermal neutron detection

    CERN Document Server

    Sidorenko, A V; Dorenbos, P; Le Masson, N J M; Rodnyi, P A; Eijk, C W E; Berezovskaya, I V; Dotsenko, V P

    2002-01-01

    The commercial BaFBr:Eu sup 2 sup +centre dot Gd sub 2 O sub 3 image plate (IP) is used nowadays for thermal neutron detection. However, it is rather sensitive to gamma-ray background, which can deteriorate the image quality. We focused our research on the development of new types of storage phosphors with the general formula M sub 2 B sub 5 O sub 9 Br:Ce sup 3 sup + (M=Sr, Ca). Neutron detection is based on the sup 1 sup 0 B(n,alpha) reaction. The advantages of this system are the low Z sub e sub f sub f , and the 40 times higher energy deposition resulting from the neutron capture reaction in comparison with that in the commercial IP. Here we present storage and spectroscopic properties of a series of newly synthesized haloborates. Comparative measurements with commercial IPs were done under neutron and beta irradiation. A satisfying light output of optically stimulated luminescence was achieved upon neutron irradiation.

  20. 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...

  1. Buffer thermal energy storage for a solar Brayton engine

    Science.gov (United States)

    Strumpf, H. J.; Barr, K. P.

    1981-01-01

    A study has been completed on the application of latent-heat buffer thermal energy storage to a point-focusing solar receiver equipped with an air Brayton engine. To aid in the study, a computer program was written for complete transient/stead-state Brayton cycle performance. The results indicated that thermal storage can afford a significant decrease in the number of engine shutdowns as compared to operating without thermal storage. However, the number of shutdowns does not continuously decrease as the storage material weight increases. In fact, there appears to be an optimum weight for minimizing the number of shutdowns.

  2. Thermal energy storage - overview and specific insight into nitrate salts for sensible and latent heat storage.

    Science.gov (United States)

    Pfleger, Nicole; Bauer, Thomas; Martin, Claudia; Eck, Markus; Wörner, Antje

    2015-01-01

    Thermal energy storage (TES) is capable to reduce the demand of conventional energy sources for two reasons: First, they prevent the mismatch between the energy supply and the power demand when generating electricity from renewable energy sources. Second, utilization of waste heat in industrial processes by thermal energy storage reduces the final energy consumption. This review focuses mainly on material aspects of alkali nitrate salts. They include thermal properties, thermal decomposition processes as well as a new method to develop optimized salt systems.

  3. Hot Thermal Storage in a Variable Power, Renewable Energy System

    Science.gov (United States)

    2014-06-01

    stores that energy thermally in the residential water heaters . 8 Beyond water, work has occurred for several other storage mediums. Pokhrel et al...MicroGrid Water Heater Hot water for use Thermal Storage Tank Return Loop Cold Inlet 31 increase the speed of the pump as the temperature of the...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited HOT THERMAL

  4. Modelling and monitoring of Aquifer Thermal Energy Storage : impacts of soil heterogeneity, thermal interference and bioremediation

    NARCIS (Netherlands)

    Sommer, W.T.

    2015-01-01

    Modelling and monitoring of Aquifer Thermal Energy Storage Impacts of heterogeneity, thermal interference and bioremediation Wijbrand Sommer
    PhD thesis, Wageningen University, Wageningen, NL (2015)
    ISBN 978-94-6257-294-2 Abstract Aquifer thermal energy storage (ATES) is

  5. Evaluation of solar thermal storage for base load electricity generation

    Science.gov (United States)

    Adinberg, R.

    2012-10-01

    In order to stabilize solar electric power production during the day and prolong the daily operating cycle for several hours in the nighttime, solar thermal power plants have the options of using either or both solar thermal storage and fossil fuel hybridization. The share of solar energy in the annual electricity production capacity of hybrid solar-fossil power plants without energy storage is only about 20%. As it follows from the computer simulations performed for base load electricity demand, a solar annual capacity as high as 70% can be attained by use of a reasonably large thermal storage capacity of 22 full load operating hours. In this study, the overall power system performance is analyzed with emphasis on energy storage characteristics promoting a high level of sustainability for solar termal electricity production. The basic system parameters, including thermal storage capacity, solar collector size, and annual average daily discharge time, are presented and discussed.

  6. Buffer thermal energy storage for an air Brayton solar engine

    Science.gov (United States)

    Strumpf, H. J.; Barr, K. P.

    1981-01-01

    The application of latent-heat buffer thermal energy storage to a point-focusing solar receiver equipped with an air Brayton engine was studied. To demonstrate the effect of buffer thermal energy storage on engine operation, a computer program was written which models the recuperator, receiver, and thermal storage device as finite-element thermal masses. Actual operating or predicted performance data are used for all components, including the rotating equipment. Based on insolation input and a specified control scheme, the program predicts the Brayton engine operation, including flows, temperatures, and pressures for the various components, along with the engine output power. An economic parametric study indicates that the economic viability of buffer thermal energy storage is largely a function of the achievable engine life.

  7. Eutectic mixtures of capric acid and lauric acid applied in building wallboards for heat energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Lv Shilei; Zhu Neng [Tianjin University (China). School of Environmental Science and Technology; Feng Guohui [Shenyang Jianzhu University, Shenyang (China)

    2006-06-15

    Capric acid (CA) and lauric acid (LA), as phase change materials (PCM), can be applied for energy storage in low temperature. The phase transitions temperature and values of latent heat of eutectic mixtures of CA and LA are suitable for being incorporated with building materials to form phase change wallboards used for building energy storage. 120, 240 and 360 accelerated thermal cycle tests were conducted to study the changes in latent heat of fusion and melting temperature of phase change wallboards combined with the eutectic mixtures of CA and LA. Differential scanning calorimetry (DSC) tested the transition temperature and latent heat. The results showed that the melting temperature and latent heat of these phase change wallboards with eutectic mixtures have not obvious variations after repeated 360 thermal cycles, which proved that these phase change wallboards have good thermal stability for melting temperature and variations in latent heat of fusion for long time application. Therefore, they can be used for latent heat storage in the field of building energy conservation. (author)

  8. Eutectic mixtures of capric acid and lauric acid applied in building wallboards for heat energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Shilei, L.; Neng, Z. [School of Environment Science and Technology, Tianjin University, Tianjin (China); Guohui, F. [Shenyang Jianzhu University, Shenyang (China)

    2006-07-01

    Capric acid (CA) and lauric acid (LA), as phase change materials (PCM), can be applied for energy storage in low temperature. The phase transition temperature and values of latent heat of eutectic mixtures of CA and LA are suitable for being incorporated with building materials to form phase change wallboards used for building energy storage. 120, 240 and 360 accelerated thermal cycle tests were conducted to study the changes in latent heat of fusion and melting temperature of phase change wallboards combined with the eutectic mixtures of CA and LA. Differential scanning calorimetry (DSC) tested the transition temperature and latent heat. The results showed that the melting temperature and latent heat of these phase change wallboards with eutectic mixtures have no obvious variations after repeated 360 thermal cycles, which proved that these phase change wallboards have good thermal stability for melting temperature and variations in latent heat of fusion for long time application. Therefore, they can be used for latent heat storage in the field of building energy conservation. (author)

  9. Heat of fusion storage systems for combined solar systems in low energy buildings

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Furbo, Simon

    2004-01-01

    Solar heating systems for combined domestic hot water and space heating has a large potential especially in low energy houses where it is possible to take full advantage of low temperature heating systems. If a building integrated heating system is used – e.g. floor heating - the supply temperature...... (and the the return temperature) would only be a few degrees above room temperature due to the very low heating demand and the large heat transfer surface area. One of the objectives in a newly started IEA Task 32 project is to investigate and develop improved thermal storages for combined solar...... from solid to liquid form (Fig. 1). Keeping the temperature as low as possible is an efficient way to reduce the heat loss from the storage. Furthermore, the PCM storage might be smaller than the equivalent water storage as more energy can be stored per volume. If the PCM further has the possibility...

  10. Finite Element Method Modeling of Sensible Heat Thermal Energy Storage with Innovative Concretes and Comparative Analysis with Literature Benchmarks

    Directory of Open Access Journals (Sweden)

    Claudio Ferone

    2014-08-01

    Full Text Available Efficient systems for high performance buildings are required to improve the integration of renewable energy sources and to reduce primary energy consumption from fossil fuels. This paper is focused on sensible heat thermal energy storage (SHTES systems using solid media and numerical simulation of their transient behavior using the finite element method (FEM. Unlike other papers in the literature, the numerical model and simulation approach has simultaneously taken into consideration various aspects: thermal properties at high temperature, the actual geometry of the repeated storage element and the actual storage cycle adopted. High-performance thermal storage materials from the literatures have been tested and used here as reference benchmarks. Other materials tested are lightweight concretes with recycled aggregates and a geopolymer concrete. Their thermal properties have been measured and used as inputs in the numerical model to preliminarily evaluate their application in thermal storage. The analysis carried out can also be used to optimize the storage system, in terms of thermal properties required to the storage material. The results showed a significant influence of the thermal properties on the performances of the storage elements. Simulation results have provided information for further scale-up from a single differential storage element to the entire module as a function of material thermal properties.

  11. Experimental measurements of thermal properties of high-temperature refractory materials used for thermal energy storage

    Science.gov (United States)

    El-Leathy, Abdelrahman; Jeter, Sheldon; Al-Ansary, Hany; Abdel-Khalik, Said; Golob, Matthew; Danish, Syed Noman; Saeed, Rageh; Djajadiwinata, Eldwin; Al-Suhaibani, Zeyad

    2016-05-01

    This paper builds on studies conducted on thermal energy storage (TES) systems that were built as a part of the work performed for a DOE-funded SunShot project titled "High Temperature Falling Particle Receiver". In previous studies, two small-scale TES systems were constructed for measuring heat loss at high temperatures that are compatible with the falling particle receiver concept, both of which had shown very limited heat loss. Through the course of those studies, it became evident that there was a lack of information about the thermal performance of some of the insulating refractory materials used in the experiments at high temperatures, especially insulating firebrick and perlite concrete. This work focuses on determining the thermal conductivities of those materials at high temperatures. The apparatus consists of a prototype cylindrical TES bin built with the same wall construction used in previous studies. An electric heater is placed along the centerline of the bin, and thermocouples are used to measure temperature at the interfaces between all layers. Heat loss is measured across one of the layers whose thermal conductivity had already been well established using laboratory experiments. This value is used to deduce the thermal conductivity of other layers. Three interior temperature levels were considered; namely, 300°C, 500°C, and 700°C. Results show that the thermal conductivity of insulating firebrick remains low (approximately 0.22 W/m.K) at an average layer temperature as high as 640°C, but it was evident that the addition of mortar had an impact on its effective thermal conductivity. Results also show that the thermal conductivity of perlite concrete is very low, approximately 0.15 W/m.K at an average layer temperature of 360°C. This is evident by the large temperature drop that occurs across the perlite concrete layer. These results should be useful for future studies, especially those that focus on numerical modeling of TES bins.

  12. The thermal performance of earth buildings

    Directory of Open Access Journals (Sweden)

    Heathcote, K.

    2011-09-01

    Full Text Available This paper examines the theoretical basis for the thermal performance of earth walls and links it to some test results on buildings constructed by the author, and to their predicted performance using a sophisticated computer modelling program. The analysis shows that for all earth walls the steady state thermal resistance is low but that for walls greater than about 450 mm thick the cyclic thermal resistance is high and increases exponentially. Whilst the steady state resistance of all thickness walls is low and results in higher than normal average temperatures in summer and lower than normal in winter the ability of thick earth walls to even out the swings in temperature is thought to be responsible for the materials reputation. The paper notes that good passive design principles (such as providing internal thermal mass and large areas of glazing for winter performance will greatly improve the performance of earth buildings with thin walls, but it is the author’s opinion that external earth walls should be at least 450 mm thick to gain the full benefit of thermal mass.

    Este artículo examina la base teórica del comportamiento térmico de las paredes de tierra y la relaciona con varios resultados de test realizados sobre edificios construidos por el autor, y con su comportamiento previsto utilizando un sofisticado programa de modelado por ordenador. El análisis muestra que la resistencia térmica constante es baja para todas las paredes de tierra, pero que para muros con un grosor mayor que 450 mm la resistencia térmica cíclica es alta y se incrementa exponencialmente. Mientras que la resistencia térmica constante de las paredes de cualquier grosor es baja y se traduce en temperaturas más altas que la media en verano y más bajas que la media en invierno, la capacidad de las paredes gruesas de tierra para amortiguar las variaciones de temperatura es la responsable de la reputación de los materiales. El artículo señala que los

  13. Numerical Modeling of a Shallow Borehole Thermal Energy Storage System

    Science.gov (United States)

    Catolico, N.; Ge, S.; Lu, N.; McCartney, J. S.

    2014-12-01

    Borehole thermal energy storage (BTES) combined with solar thermal energy harvesting is an economic technological system to garner and store energy as well as an environmentally-sustainable alternative for the heating of buildings. The first community-scale BTES system in North America was installed in 2007 in the Drake Landing Solar Community (DLSC), about 35 miles south of Calgary, Canada. The BTES system involves direct circulation of water heated from solar thermal panels in the summer into a storage tank, after which it is circulate within an array of 144 closed-loop geothermal heat exchangers having a depth of 35 m and a spacing of 2.5 m. In the winter the circulation direction is reversed to supply heat to houses. Data collection over a six year period indicates that this system can supply more than 90% of the winter heating energy needs for 52 houses in the community. One major challenge facing the BTES system technology is the relatively low annual efficiency, i.e., the ratio of energy input and output is in the range of 15% to 40% for the system in Drake Landing. To better understand the working principles of BTES and to improve BTES performance for future applications at larger scales, a three-dimensional transient coupled fluid and heat transfer model is established using TOUGH2. The time-dependent injection temperatures and circulation rate measured over the six years of monitoring are used as model input. The simulations are calibrated using soil temperature data measured at different locations over time. The time-dependent temperature distributions within the borehole region agree well with the measured temperatures for soil with an intrinsic permeability of 10e-19 m2, an apparent thermal conductivity of 2.03 W/m°C, and a volumetric heat capacity of 2.31 MJ/m-3°C. The calibrated model serves as the basis for a sensitivity analysis of soil and operational parameters on BTES system efficiency preformed with TOUGH2. Preliminary results suggest 1) BTES

  14. Theoretical and Experimental Thermal Performance Analysis of Complex Thermal Storage Membrane Containing Bio-Based Phase Change Material (PCM)

    Energy Technology Data Exchange (ETDEWEB)

    Kosny, Jan [ORNL; Stovall, Therese K [ORNL; Shrestha, Som S [ORNL; Yarbrough, David W [ORNL

    2010-01-01

    Since 2000, an ORNL research team has been testing different configurations of PCM-enhanced building envelop components to be used in residential and commercial buildings. During 2009, a novel type of thermal storage membrane was evaluated for building envelope applications. Bio-based PCM was encapsulated between two layers of heavy-duty plastic film forming a complex array of small PCM cells. Today, a large group of PCM products are packaged in such complex PCM containers or foils containing arrays of PCM pouches of different shapes and sizes. The transient characteristics of PCM-enhanced building envelope materials depend on the quality and amount of PCM, which is very often difficult to estimate because of the complex geometry of many PCM heat sinks. The only widely used small-scale analysis method used to evaluate the dynamic characteristics of PCM-enhanced building products is the differential scanning calorimeter (DSC). Unfortunately, this method requires relatively uniform, and very small, specimens of the material. However, in numerous building thermal storage applications, PCM products are not uniformly distributed across the surface area, making the results of traditional DSC measurements unrealistic for these products. In addition, most of the PCM-enhanced building products contain blends of PCM with fire retardants and chemical stabilizers. This combination of non-uniform distribution and non-homogenous composition make it nearly impossible to select a representative small specimen suitable for DSC tests. Recognizing these DSC limitations, ORNL developed a new methodology for performing dynamic heat flow analysis of complex PCM-enhanced building materials. An experimental analytical protocol to analyze the dynamic characteristics of PCM thermal storage makes use of larger specimens in a conventional heat-flow meter apparatus, and combines these experimental measurements with three-dimensional (3-D) finite-difference modeling and whole building energy

  15. Theoretical and Experimental Thermal Performance Analysis of Complex Thermal Storage Membrane Containing Bio-Based Phase Change Material (PCM)

    Energy Technology Data Exchange (ETDEWEB)

    Kosny, Jan [ORNL; Stovall, Therese K [ORNL; Shrestha, Som S [ORNL; Yarbrough, David W [ORNL

    2010-12-01

    Since 2000, an ORNL research team has been testing different configurations of PCM-enhanced building envelop components to be used in residential and commercial buildings. During 2009, a novel type of thermal storage membrane was evaluated for building envelope applications. Bio-based PCM was encapsulated between two layers of heavy-duty plastic film forming a complex array of small PCM cells. Today, a large group of PCM products are packaged in such complex PCM containers or foils containing arrays of PCM pouches of different shapes and sizes. The transient characteristics of PCM-enhanced building envelope materials depend on the quality and amount of PCM, which is very often difficult to estimate because of the complex geometry of many PCM heat sinks. The only widely used small-scale analysis method used to evaluate the dynamic characteristics of PCM-enhanced building products is the differential scanning calorimeter (DSC). Unfortunately, this method requires relatively uniform, and very small, specimens of the material. However, in numerous building thermal storage applications, PCM products are not uniformly distributed across the surface area, making the results of traditional DSC measurements unrealistic for these products. In addition, most of the PCM-enhanced building products contain blends of PCM with fire retardants and chemical stabilizers. This combination of non-uniform distribution and non-homogenous composition make it nearly impossible to select a representative small specimen suitable for DSC tests. Recognizing these DSC limitations, ORNL developed a new methodology for performing dynamic heat flow analysis of complex PCM-enhanced building materials. An experimental analytical protocol to analyze the dynamic characteristics of PCM thermal storage makes use of larger specimens in a conventional heat-flow meter apparatus, and combines these experimental measurements with three-dimensional (3-D) finite-difference modeling and whole building energy

  16. Expected benefits of federally-funded thermal energy storage research

    Energy Technology Data Exchange (ETDEWEB)

    Spanner, G E; Daellenbach, K K; Hughes, K R; Brown, D R; Drost, M K

    1992-09-01

    Pacific Northwest Laboratory (PNL) conducted this study for the Office of Advanced Utility Concepts of the US Department of Energy (DOE). The objective of this study was to develop a series of graphs that depict the long-term benefits of continuing DOE's thermal energy storage (TES) research program in four sectors: building heating, building cooling, utility power production, and transportation. The study was conducted in three steps- The first step was to assess the maximum possible benefits technically achievable in each sector. In some sectors, the maximum benefit was determined by a supply side'' limitation, and in other sectors, the maximum benefit is determined by a demand side'' limitation. The second step was to apply economic cost and diffusion models to estimate the benefits that are likely to be achieved by TES under two scenarios: (1) with continuing DOE funding of TES research, and (2) without continued funding. The models all cover the 20-year period from 1990 to 2010. The third step was to prepare graphs that show the maximum technical benefits achievable, the estimated benefits with TES research funding, and the estimated benefits in the absence of TES research funding. The benefits of federally-funded TES research are largely in four areas: displacement of primary energy, displacement of oil and natural gas, reduction in peak electric loads, and emissions reductions.

  17. Expected benefits of federally-funded thermal energy storage research

    Energy Technology Data Exchange (ETDEWEB)

    Spanner, G.E.; Daellenbach, K.K.; Hughes, K.R.; Brown, D.R.; Drost, M.K.

    1992-09-01

    Pacific Northwest Laboratory (PNL) conducted this study for the Office of Advanced Utility Concepts of the US Department of Energy (DOE). The objective of this study was to develop a series of graphs that depict the long-term benefits of continuing DOE`s thermal energy storage (TES) research program in four sectors: building heating, building cooling, utility power production, and transportation. The study was conducted in three steps- The first step was to assess the maximum possible benefits technically achievable in each sector. In some sectors, the maximum benefit was determined by a ``supply side`` limitation, and in other sectors, the maximum benefit is determined by a ``demand side`` limitation. The second step was to apply economic cost and diffusion models to estimate the benefits that are likely to be achieved by TES under two scenarios: (1) with continuing DOE funding of TES research, and (2) without continued funding. The models all cover the 20-year period from 1990 to 2010. The third step was to prepare graphs that show the maximum technical benefits achievable, the estimated benefits with TES research funding, and the estimated benefits in the absence of TES research funding. The benefits of federally-funded TES research are largely in four areas: displacement of primary energy, displacement of oil and natural gas, reduction in peak electric loads, and emissions reductions.

  18. Field testing of a high-temperature aquifer thermal energy storage system

    Energy Technology Data Exchange (ETDEWEB)

    Sterling, R.L.; Hoyer, M.C. [Univ. of Minnesota, Minneapolis, MN (United States)

    1989-03-01

    The University of Minnesota Aquifer Thermal Energy Storage (ATES) System has been operated as a field test facility for the past six years. Four short-term and two long-term cycles have been completed to data providing a greatly increased understanding of the efficiency and geochemical effects of high-temperature aquifer thermal energy storage. A third long-term cycle is currently being planned to operate the ATES system in conjunction with a real heating load and to further study the geochemical impact on the aquifer from heated waste storage cycles. The most critical activities in the preparation for the next cycle have proved to be the applications for the various permits and variances necessary to conduct the third cycle and the matching of the characteristics of the ATES system during heat recovery with a suitable adjacent building thermal load.

  19. Thermal Performance of the Storage Brick Containing Microencapsulated PCM

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Gyu

    1998-02-15

    The utilization of microencapsulated phase change materials(PCMs) provides several advantages over conventional PCM application. The heat storage system, as well as heat recovery system, can be built to a smaller size than the normal systems for a given thermal cycling capacity. This microencapsulated PCM technique has not yet been commercialized, however. In this work sodium acetate trihydrate(CH{sub 3}COONa {center_dot} 3H{sub 2}O) was selected for the PCM and was encapsulated. This microencapsulated PCM was mixed with cement mortar for utilization as a floor heating system. In this experiment performed here the main purpose was to investigate the thermal performance of a storage brick with microencapsulated PCM concentration. The thermal performance of this storage brick is dependent on PCM concentration, flow rate and cooling temperature of the heat transfer fluid, etc. The results showed that cycle time was shortened as the PCM content was increased and as the mass flow rate was increased. The same effect was obtained when the cooling temperature was decreased. For each thermal storage brick the overall heat transfer coefficient(U-value) was constant for a 0% brick, but was increased with time for the bricks containing microencapsulated PCM. For the same mass flow rate, as the cooling temperature decreased, the amount of heat withdrawn increased, and in particular a critical cooling temperature was found for each thermal storage brick. The average effectiveness of each thermal storage brick was found to be approximately 48%, 51% and 58% respectively.

  20. Thermal energy storage. [by means of chemical reactions

    Science.gov (United States)

    Grodzka, P. G.

    1975-01-01

    The principles involved in thermal energy storage by sensible heat, chemical potential energy, and latent heat of fusion are examined for the purpose of evolving selection criteria for material candidates in the low ( 0 C) and high ( 100 C) temperature ranges. The examination identifies some unresolved theoretical considerations and permits a preliminary formulation of an energy storage theory. A number of candidates in the low and high temperature ranges are presented along with a rating of candidates or potential candidates. A few interesting candidates in the 0 to 100 C region are also included. It is concluded that storage by means of reactions whose reversibility can be controlled either by product removal or by catalytic means appear to offer appreciable advantages over storage with reactions whose reversability cannot be controlled. Among such advantages are listed higher heat storage capacities and more favorable options regarding temperatures of collection, storage, and delivery. Among the disadvantages are lower storage efficiencies.

  1. Envelope Thermal Design Optimization for Urban Residential Buildings in Malawi

    OpenAIRE

    2016-01-01

    This study sought to optimize the envelope thermal design of free-running urban residential buildings in Malawi. It specifically set out to improve the urban residential buildings’ thermal comfort and suggest optimal envelope thermal design features for these buildings. The research study was primarily dependent on computer simulations in EnergyPlus to replicate the typical Malawian urban residential building’s thermal behaviour and then study the impacts of various envelope configurations on...

  2. Design Considerations of a Solid State Thermal Energy Storage

    Science.gov (United States)

    Janbozorgi, Mohammad; Houssainy, Sammy; Thacker, Ariana; Ip, Peggy; Ismail, Walid; Kavehpour, Pirouz

    2016-11-01

    With the growing governmental restrictions on carbon emission, renewable energies are becoming more prevalent. A reliable use of a renewable source however requires a built-in storage to overcome the inherent intermittent nature of the available energy. Thermal design of a solid state energy storage has been investigated for optimal performance. The impact of flow regime, laminar vs. turbulent, on the design and sizing of the system is also studied. The implications of low thermal conductivity of the storage material are discussed and a design that maximizes the round trip efficiency is presented. This study was supported by Award No. EPC-14-027 Granted by California Energy Commission (CEC).

  3. Green Building Construction Thermal Isolation Materials (Rockwool

    Directory of Open Access Journals (Sweden)

    M. Itewi

    2011-01-01

    Full Text Available Problem statement: Building insulation consisting roughly to anything in a structure that is utilizes as insulation for any reason. Thermal insulation in structures is a significant feature to attaining thermal comfort for its tenants. Approach: Insulation decreases unnecessary warmth loss or gain and can reduce the power burdens of heating and cooling structures. It does not automatically having anything to do with problems of sufficient exposure to air and might or might not influence the amount of sound insulation. Results: In a constricted way insulation can just mean the insulation substance used to reduce heat loss, such as: Glass wool, cellulose, polystyrene, rock wool, urethane foam, vermiculite and the earth, but it can also entail a variety of plans and methods used to deal with the chief forms of heat movement like transmission, emission and convection substances. The efficiency of insulation is normally assessed by its R-value. However, an R-value does not allow for the superiority of assembly or narrow green issues for each structure. Building superiority matters comprise insufficient vapor obstructions and troubles with draft-proofing. Additionally, the property and concentration of the insulation substance itself is vital. Fiberglass insulation materials, for example, made out of short fibers of glass covered on top of each other is not as long-lasting as insulation prepared from extended entwined fibers of glass. Conclusion/Recommendations: Rockwool insulation is a kind of insulation that is constructed out of real rocks and minerals. It furthermore is known by the names of mineral wool insulation, stone wool insulation or slag wool insulation. A broad collection of goods can be constructed from Rockwool, because of its outstanding capability to obstruct sound and heat. Rockwool insulation is normally utilized in building assembly, manufacturing plants and in automotive purposes. In this study i proposed to use

  4. Wind Energy to Thermal and Cold Storage – A Systems Approach

    DEFF Research Database (Denmark)

    Xydis, George

    2013-01-01

    In this paper wind energy to thermal and cold storage scenarios were examined to enable high wind integration through converting renewable electricity excess into thermal or cooling energy, saving part of the energy used in an area and eliminating the need to possibly build a new coal fired plant....... Case studies in Crete Island (not interconnected to the power grid of Greek mainland) with onshore wind power installed were investigated. The aim of this work was to review the options for greater integration of renewables into the grid and the main idea was to analyze the wind to thermal and to cold...

  5. Modeling delamination due to thermal stress in optical storage media

    Science.gov (United States)

    Nkansah, M. A.; Evans, K. E.

    1990-04-01

    Finite element analysis is used to calculate the shape of blisters formed in bilayer optical storage media due to the buildup of thermal stresses during laser writing. It is shown that practically usable blisters may be expected to form in a time period of about 15 ns. Such a thermal stress delamination process may also precede melting in conventional pit formation processes.

  6. Aquifer thermal energy storage reference manual: seasonal thermal energy storage program

    Energy Technology Data Exchange (ETDEWEB)

    Prater, L.S.

    1980-01-01

    This is the reference manual of the Seasonal Thermal Energy Storage (STES) Program, and is the primary document for the transfer of technical information of the STES Program. It has been issued in preliminary form and will be updated periodically to include more technical data and results of research. As the program progresses and new technical data become available, sections of the manual will be revised to incorporate these data. This primary document contains summaries of: the TRW, incorporated demonstration project at Behtel, Alaska, Dames and Moore demonstration project at Stony Brook, New York, and the University of Minnesota demonstration project at Minneapolis-St. Paul, Minnesota; the technical support programs including legal/institutional assessment; economic assessment; environmental assessment; field test facilities; a compendia of existing information; numerical simulation; and non-aquifer STES concepts. (LCL)

  7. A solar air collector with integrated latent heat thermal storage

    OpenAIRE

    Klimes Lubomir; Mauder Tomas; Ostry Milan; Charvat Pavel

    2012-01-01

    Simulations of the behaviour of a solar air collector with integrated latent heat thermal storage were performed. The model of the collector was created with the use of coupling between TRNSYS 17 and MATLAB. Latent heat storage (Phase Change Material - PCM) was integrated with the solar absorber. The model of the latent heat storage absorber was created in MATLAB and the model of the solar air collector itself was created in TRNSYS with the use of TYPE 56. The model of the latent heat storage...

  8. Integration of Decentralized Thermal Storages Within District Heating (DH Networks

    Directory of Open Access Journals (Sweden)

    Schuchardt Georg K.

    2016-12-01

    Full Text Available Thermal Storages and Thermal Accumulators are an important component within District Heating (DH systems, adding flexibility and offering additional business opportunities for these systems. Furthermore, these components have a major impact on the energy and exergy efficiency as well as the heat losses of the heat distribution system. Especially the integration of Thermal Storages within ill-conditioned parts of the overall DH system enhances the efficiency of the heat distribution. Regarding an illustrative and simplified example for a DH system, the interactions of different heat storage concepts (centralized and decentralized and the heat losses, energy and exergy efficiencies will be examined by considering the thermal state of the heat distribution network.

  9. Rapid charging of thermal energy storage materials through plasmonic heating.

    Science.gov (United States)

    Wang, Zhongyong; Tao, Peng; Liu, Yang; Xu, Hao; Ye, Qinxian; Hu, Hang; Song, Chengyi; Chen, Zhaoping; Shang, Wen; Deng, Tao

    2014-01-01

    Direct collection, conversion and storage of solar radiation as thermal energy are crucial to the efficient utilization of renewable solar energy and the reduction of global carbon footprint. This work reports a facile approach for rapid and efficient charging of thermal energy storage materials by the instant and intense photothermal effect of uniformly distributed plasmonic nanoparticles. Upon illumination with both green laser light and sunlight, the prepared plasmonic nanocomposites with volumetric ppm level of filler concentration demonstrated a faster heating rate, a higher heating temperature and a larger heating area than the conventional thermal diffusion based approach. With controlled dispersion, we further demonstrated that the light-to-heat conversion and thermal storage properties of the plasmonic nanocomposites can be fine-tuned by engineering the composition of the nanocomposites.

  10. Metal hydrides for concentrating solar thermal power energy storage

    Science.gov (United States)

    Sheppard, D. A.; Paskevicius, M.; Humphries, T. D.; Felderhoff, M.; Capurso, G.; Bellosta von Colbe, J.; Dornheim, M.; Klassen, T.; Ward, P. A.; Teprovich, J. A.; Corgnale, C.; Zidan, R.; Grant, D. M.; Buckley, C. E.

    2016-04-01

    The development of alternative methods for thermal energy storage is important for improving the efficiency and decreasing the cost of concentrating solar thermal power. We focus on the underlying technology that allows metal hydrides to function as thermal energy storage (TES) systems and highlight the current state-of-the-art materials that can operate at temperatures as low as room temperature and as high as 1100 °C. The potential of metal hydrides for thermal storage is explored, while current knowledge gaps about hydride properties, such as hydride thermodynamics, intrinsic kinetics and cyclic stability, are identified. The engineering challenges associated with utilising metal hydrides for high-temperature TES are also addressed.

  11. Modeling Pumped Thermal Energy Storage with Waste Heat Harvesting

    Science.gov (United States)

    Abarr, Miles L. Lindsey

    This work introduces a new concept for a utility scale combined energy storage and generation system. The proposed design utilizes a pumped thermal energy storage (PTES) system, which also utilizes waste heat leaving a natural gas peaker plant. This system creates a low cost utility-scale energy storage system by leveraging this dual-functionality. This dissertation first presents a review of previous work in PTES as well as the details of the proposed integrated bottoming and energy storage system. A time-domain system model was developed in Mathworks R2016a Simscape and Simulink software to analyze this system. Validation of both the fluid state model and the thermal energy storage model are provided. The experimental results showed the average error in cumulative fluid energy between simulation and measurement was +/- 0.3% per hour. Comparison to a Finite Element Analysis (FEA) model showed energy of a recently proposed Pumped Thermal Energy Storage and Bottoming System (Bot-PTES) that uses ammonia as the working fluid. This analysis focused on the effects of hot thermal storage utilization, system pressure, and evaporator/condenser size on the system performance. This work presents the estimated performance for a proposed baseline Bot-PTES. Results of this analysis showed that all selected parameters had significant effects on efficiency, with the evaporator/condenser size having the largest effect over the selected ranges. Results for the baseline case showed stand-alone energy storage efficiencies between 51 and 66% for varying power levels and charge states, and a stand-alone bottoming efficiency of 24%. The resulting efficiencies for this case were low compared to competing technologies; however, the dual-functionality of the Bot-PTES enables it to have higher capacity factor, leading to 91-197/MWh levelized cost of energy compared to 262-284/MWh for batteries and $172-254/MWh for Compressed Air Energy Storage.

  12. A first-order thermal model for building design

    Energy Technology Data Exchange (ETDEWEB)

    Mathews, E.H. [Centre for Experimental and Numerical Thermoflow, Univ. of Pretoria (South Africa); Richards, P.G. [Centre for Experimental and Numerical Thermoflow, Univ. of Pretoria (South Africa); Lombard, C. [Centre for Experimental and Numerical Thermoflow, Univ. of Pretoria (South Africa)

    1994-12-31

    Simplified thermal models of buildings can successfully be applied in building design. This paper describes the derivation and validation of a first-order thermal model which has a clear physical interpretation, is based on uncomplicated calculation procedures and requires limited input information. Because extensive simplifications and assumptions are inherent in the development of the model, a comprehensive validation study is reported. The validity of the thermal model was proven with 70 validation studies in 32 buildings comprising a wide range of thermal characteristics. The accuracy of predictions compares well with other sophisticated programs. The proposed model is considered to be eminently suitable for incorporation in an efficient design tool. (orig.)

  13. Preliminary survey and evaluation of nonaquifer thermal energy storage concepts for seasonal storage

    Energy Technology Data Exchange (ETDEWEB)

    Blahnik, D.E.

    1980-11-01

    Thermal energy storage enables the capture and retention of heat energy (or cold) during one time period for use during another. Seasonal thermal energy storage (STES) involves a period of months between the input and recovery of energy. The purpose of this study was to make a preliminary investigation and evaluation of potential nonaquifer STES systems. Current literature was surveyed to determine the state of the art of thermal energy storage (TES) systems such as hot water pond storage, hot rock storage, cool ice storage, and other more sophisticated concepts which might have potential for future STES programs. The main energy sources for TES principally waste heat, and the main uses of the stored thermal energy, i.e., heating, cooling, and steam generation are described. This report reviews the development of sensible, latent, and thermochemical TES technologies, presents a preliminary evaluation of the TES methods most applicable to seasonal storage uses, outlines preliminary conclusions drawn from the review of current TES literature, and recommends further research based on these conclusions. A bibliography of the nonaquifer STES literature review, and examples of 53 different TES concepts drawn from the literature are provided. (LCL)

  14. Thermal performance of a passive solar office building in Portugal

    OpenAIRE

    Gonçalves, Helder; Silva, António Rocha e; Rodrigues, Carlos

    2008-01-01

    This paper presents the thermal performance of a Passive Solar Office Building in Portugal in winter and summer 2006 and 2007. This Building, called Solar XXI, pretends to be an example of passive design both for heating and cooling. It contains a direct gain system assisted by a solar thermal system for winter conditions. In summer a ground cooling system (buried pipes) is used to cool the building, together with night cooling strategies. It also integrate in the vertical south envelope a Ph...

  15. Space Station thermal storage/refrigeration system research and development

    Science.gov (United States)

    Dean, W. G.; Karu, Z. S.

    1993-02-01

    Space Station thermal loading conditions represent an order of magnitude increase over current and previous spacecraft such as Skylab, Apollo, Pegasus III, Lunar Rover Vehicle, and Lockheed TRIDENT missiles. Thermal storage units (TSU's) were successfully used on these as well as many applications for ground based solar energy storage applications. It is desirable to store thermal energy during peak loading conditions as an alternative to providing increased radiator surface area which adds to the weight of the system. Basically, TSU's store heat by melting a phase change material (PCM) such as a paraffin. The physical property data for the PCM's used in the design of these TSU's is well defined in the literature. Design techniques are generally well established for the TSU's. However, the Space Station provides a new challenge in the application of these data and techniques because of three factors: the large size of the TSU required, the integration of the TSU for the Space Station thermal management concept with its diverse opportunities for storage application, and the TSU's interface with a two-phase (liquid/vapor) thermal bus/central heat rejection system. The objective in the thermal storage research and development task was to design, fabricate, and test a demonstration unit. One test article was to be a passive thermal storage unit capable of storing frozen food at -20 F for a minimum of 90 days. A second unit was to be capable of storing frozen biological samples at -94 F, again for a minimum of 90 days. The articles developed were compatible with shuttle mission conditions, including safety and handling by astronauts. Further, storage rack concepts were presented so that these units can be integrated into Space Station logistics module storage racks. The extreme sensitivity of spacecraft radiator systems design-to-heat rejection temperature requirements is well known. A large radiator area penalty is incurred if low temperatures are accommodated via a

  16. Development of an innovative spacecraft thermal storage device

    Science.gov (United States)

    Parrish, Clyde F.; Scaringe, Robert P.; Pratt, David M.

    Several adsorbent-refrigerant pairs have been examined which demonstrate that the innovative heat-pump-adsorption storage device (HPASD) presented can provide significant thermal storage in a vapor-compressor heat pump. The thermal storage capacity of HPASD systems with methanol on calcium chloride as the adsorbent pair was 54.8 kJ/kg with a radiator area of 17 sq m for a 50-kW peak thermal load. Values for a pumped loop were 15 kJ/kg with a 202-sq m radiator area. Heat pumps with methanol as the working fluid have a storage capacity of 24 kJ/kg and a radiator area of 70 sq m. Phase change materials have values in the range of 12.6 kJ/kg (n-octadecane with a 30 deg delta T) to 37 kJ/kg (gallium with a 10 deg delta T). The radiator areas for these phase change systems range from 225 to 43 sq m, respectively. Data collected to date indicate that the HPASD device has superior thermal storage characteristics when compared with other systems under typical use conditions.

  17. Modelling the Size of Seasonal Thermal Storage in the Solar District Heating System

    Directory of Open Access Journals (Sweden)

    Giedrė Streckienė

    2012-12-01

    Full Text Available The integration of a thermal storage system into the solar heating system enables to increase the use of solar thermal energy in buildings and allows avoiding the mismatch between consumers’ demand and heat production in time. The paper presents modelling a seasonal thermal storage tank various sizes of which have been analyzed in the district solar heating system that could cover a part of heat demand for the district of individual houses in Vilnius. A biomass boiler house, as an additional heat source, should allow covering the remaining heat demand. energyPRO software is used for system modelling. The paper evaluates heat demand, climate conditions and technical characteristics.Article in Lithuanian

  18. Thermal cycle testing of calcium chloride hexahydrate as a possible PCM for latent heat storage

    Energy Technology Data Exchange (ETDEWEB)

    Tyagi, V.V.; Buddhi, D. [Thermal Energy Storage Laboratory, School of Energy and Environmental Studies, Devi Ahilya University, Indore 452017 (India)

    2008-08-15

    In order to study the changes in latent heat of fusion and melting temperature of calcium chloride hexahydrate (CaCl{sub 2}.6H{sub 2}O) inorganic salt as a latent heat storage material, a thousand accelerated thermal cycle tests have been conducted. The effect of thermal cycling and the reliability in terms of the changing of the melting temperature using a differential scanning calorimeter (DSC) is determined. It has been noticed that the CaCl{sub 2}.6H{sub 2}O melts between a stable range of temperature and has shown small variations in the latent heat of fusion during the thermal cycling process. Thus, it can be a promising phase change material (PCM) for heating and cooling applications for various building/storage systems. (author)

  19. Spent Nuclear Fuel Project Canister Storage Building Functions and Requirements

    Energy Technology Data Exchange (ETDEWEB)

    KLEM, M.J.

    2000-10-18

    In 1998, a major change in the technical strategy for managing Multi Canister Overpacks (MCO) while stored within the Canister Storage Building (CSB) occurred. The technical strategy is documented in Baseline Change Request (BCR) No. SNF-98-006, Simplified SNF Project Baseline (MCO Sealing) (FDH 1998). This BCR deleted the hot conditioning process initially adopted for the Spent Nuclear Fuel Project (SNF Project) as documented in WHC-SD-SNF-SP-005, Integrated Process Strategy for K Basins Spent Nuclear Fuel (WHC 199.5). In summary, MCOs containing Spent Nuclear Fuel (SNF) from K Basins would be placed in interim storage following processing through the Cold Vacuum Drying (CVD) facility. With this change, the needs for the Hot Conditioning System (HCS) and inerting/pressure retaining capabilities of the CSB storage tubes and the MCO Handling Machine (MHM) were eliminated. Mechanical seals will be used on the MCOs prior to transport to the CSB. Covers will be welded on the MCOs for the final seal at the CSB. Approval of BCR No. SNF-98-006, imposed the need to review and update the CSB functions and requirements baseline documented herein including changing the document title to ''Spent Nuclear Fuel Project Canister Storage Building Functions and Requirements.'' This revision aligns the functions and requirements baseline with the CSB Simplified SNF Project Baseline (MCO Sealing). This document represents the Canister Storage Building (CSB) Subproject technical baseline. It establishes the functions and requirements baseline for the implementation of the CSB Subproject. The document is organized in eight sections. Sections 1.0 Introduction and 2.0 Overview provide brief introductions to the document and the CSB Subproject. Sections 3.0 Functions, 4.0 Requirements, 5.0 Architecture, and 6.0 Interfaces provide the data described by their titles. Section 7.0 Glossary lists the acronyms and defines the terms used in this document. Section 8

  20. Test facility of thermal storage equipment for space power generation

    Science.gov (United States)

    Inoue, T.; Nakagawa, M.; Mochida, Y.; Ohtomo, F.; Shimizu, K.; Tanaka, K.; Abe, Y.; Nomura, O.; Kamimoto, M.

    A thermal storage equipment test facility has been built in connection with developing solar dynamic power systems (SDPSs). The test facility consists of a recuperative closed Brayton cycle system (CBC), with a mixture of helium and xenon with a molecular weight of 39.9 serving as the working fluid. CBC has been shown to be the most attractive power generation system among several types of SDPSs because of its ability to meet the required high power demand and its thermal efficiency, about 30 percent. The authors present a description of this test facility and give results of the preliminary test and the first-stage test with heat storage equipment.

  1. Thermal stresses in multilayer optical-storage media

    Science.gov (United States)

    Nkansah, M. A.; Evans, K. E.

    1989-07-01

    Previously, it has been shown that thermal stresses may have a significant role to play in optical-storage media. Calculations have shown that thermal stresses are produced in single-layer optical-storage thin films sufficient to cause interlayer failure and blister formation. In this paper, more realistic multilayer thin films are modeled and it is shown that considerably higher stresses can be produced depending on the layer geometry and material properties. These effects are important both in the initial writing process and in subsequent reading or writing processes, and may result in long-term-accumulated, stress-induced damage.

  2. Legal and regulatory issues affecting aquifer thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, P.L.

    1981-10-01

    This document updates and expands the report with a similar title issued in October 1980. This document examines a number of legal and regulatory issues that potentially can affect implementation of the aquifer thermal energy storage (ATES) concept. This concept involves the storage of thermal energy in an underground aquifer until a later date when it can be effectively utilized. Either heat energy or chill can be stored. Potential end uses of the energy include district space heating and cooling, industrial process applications, and use in agriculture or aquaculture. Issues are examined in four categories: regulatory requirements, property rights, potential liability, and issues related to heat or chill delivery.

  3. Novel Thermal Storage Technologies for Concentrating Solar Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Neti, Sudhakar [Lehigh Univ., Bethlehem, PA (United States). Mechanical Engineering and Mechanics; Oztekin, Alparslan [Lehigh Univ., Bethlehem, PA (United States); Chen, John [Lehigh Univ., Bethlehem, PA (United States); Tuzla, Kemal [Lehigh Univ., Bethlehem, PA (United States); Misiolek, Wojciech [Lehigh Univ., Bethlehem, PA (United States)

    2013-06-20

    The technologies that are to be developed in this work will enable storage of thermal energy in 100 MWe solar energy plants for 6-24 hours at temperatures around 300°C and 850°C using encapsulated phase change materials (EPCM). Several encapsulated phase change materials have been identified, fabricated and proven with calorimetry. Two of these materials have been tested in an airflow experiment. A cost analysis for these thermal energy storage systems has also been conducted that met the targets established at the initiation of the project.

  4. Low-temperature thermal energy storage program annual operating plan

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, H. W.; Eissenberg, D. M.

    1979-01-01

    The LTTES program operating plans for FY 1978 are described in terms of general program objectives and the technical activities being implemented to achieve these objectives. The program structure provides emphasis on several principal thrusts; namely, seasonal thermal storage, daily/short-term thermal storage, and waste heat recovery and reuse. A work breakdown structure (WBS) organizes the efforts being carried out in-house or through subcontract within each thrust area. Fiscal data are summarized in respect to thrust area, individual efforts, and funding source.

  5. A solar air collector with integrated latent heat thermal storage

    Science.gov (United States)

    Charvat, Pavel; Ostry, Milan; Mauder, Tomas; Klimes, Lubomir

    2012-04-01

    Simulations of the behaviour of a solar air collector with integrated latent heat thermal storage were performed. The model of the collector was created with the use of coupling between TRNSYS 17 and MATLAB. Latent heat storage (Phase Change Material - PCM) was integrated with the solar absorber. The model of the latent heat storage absorber was created in MATLAB and the model of the solar air collector itself was created in TRNSYS with the use of TYPE 56. The model of the latent heat storage absorber allows specification of the PCM properties as well as other parameters. The simulated air collector was the front and back pass collector with the absorber in the middle of the air cavity. Two variants were considered for comparison; the light-weight absorber made of sheet metal and the heat-storage absorber with the PCM. Simulations were performed for the climatic conditions of the Czech Republic (using TMY weather data).

  6. A solar air collector with integrated latent heat thermal storage

    Directory of Open Access Journals (Sweden)

    Klimes Lubomir

    2012-04-01

    Full Text Available Simulations of the behaviour of a solar air collector with integrated latent heat thermal storage were performed. The model of the collector was created with the use of coupling between TRNSYS 17 and MATLAB. Latent heat storage (Phase Change Material - PCM was integrated with the solar absorber. The model of the latent heat storage absorber was created in MATLAB and the model of the solar air collector itself was created in TRNSYS with the use of TYPE 56. The model of the latent heat storage absorber allows specification of the PCM properties as well as other parameters. The simulated air collector was the front and back pass collector with the absorber in the middle of the air cavity. Two variants were considered for comparison; the light-weight absorber made of sheet metal and the heat-storage absorber with the PCM. Simulations were performed for the climatic conditions of the Czech Republic (using TMY weather data.

  7. Integrated thermal simulation of buildings and regenerative evaporative coolers

    Energy Technology Data Exchange (ETDEWEB)

    Rousseau, P.G.; Mathews, E.H.; Grobler, L.J. (Pretoria Univ. (South Africa). Centre for Experimental and Numerical Thermoflow)

    1994-01-01

    The thermal environment inside a building, fitted with a regenerative evaporative cooler, is influenced by the performance of the cooler. However, this performance is again influenced by the indoor air conditions. It means that the thermal performance of the building and the performance of the cooler cannot be separated. This paper proposes an innovative model for simulating the integrated thermal performance of buildings and regenerative evaporative coolers. The cooler model employs a standard single equation to characterize the performance of a cooler. Only the coefficients of this equation differs for different coolers. These coefficients are found from empirical performance data available from suppliers. The model was integrated with a comprehensive building thermal analysis program and verified successfully. This model now enables the designer to simulate any regenerative evaporative cooler connected to any building in any climatic region. The control strategy best suited for different off-design conditions can now also be investigated. (Author)

  8. Selection of materials with potential in sensible thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, A.I.; Martinez, M.; Segarra, M. [Department of Materials Science and Metallurgical Engineering, Universitat de Barcelona, Marti i Franques 1, 08028 Barcelona (Spain); Martorell, I.; Cabeza, L.F. [GREA Innovacio Concurrent, Edifici CREA, Universitat de Lleida, Pere de Cabrera s/n, 25001 Lleida (Spain)

    2010-10-15

    Thermal energy storage is a technology under investigation since the early 1970s. Since then, numerous new applications have been found and much work has been done to bring this technology to the market. Nevertheless, the materials used either for latent or for sensible storage were mostly investigated 30 years ago, and the research has lead to improvement in their performance under different conditions of applications. In those years a significant number of new materials were developed in many fields other than storage and energy, but a great effort to characterize and classify these materials was done. Taking into account the fact that thousands of materials are known and a large number of new materials are developed every year, the authors use the methodology for materials selection developed by Prof. Ashby to give an overview of other materials suitable to be used in thermal energy storage. Sensible heat storage at temperatures between 150 and 200 C is defined as a case study and two different scenarios were considered: long term sensible heat storage and short term sensible heat storage. (author)

  9. High-temperature molten salt thermal energy storage systems

    Science.gov (United States)

    Petri, R. J.; Claar, T. D.; Tison, R. R.; Marianowski, L. G.

    1980-02-01

    The results of comparative screening studies of candidate molten carbonate salts as phase change materials (PCM) for advanced solar thermal energy storage applications at 540 to 870 C (1004 to 1600 F) and steam Rankine electric generation at 400 to 540 C (752 to 1004 F) are presented. Alkali carbonates are attractive as latent heat storage materials because of their relatively high storage capacity and thermal conductivity, low corrosivity, moderate cost, and safe and simple handling requirements. Salts were tested in 0.1 kWhr lab scale modules and evaluated on the basis of discharge heat flux, solidification temperature range, thermal cycling stability, and compatibility with containment materials. The feasibility of using a distributed network of high conductivity material to increase the heat flux through the layer of solidified salt was evaluated. The thermal performance of an 8 kWhr thermal energy storage (TES) module containing LiKCO3 remained very stable throughout 5650 hours and 130 charge/discharge cycles at 480 to 535 C (896 to 995 F). A TES utilization concept of an electrical generation peaking subsystem composed of a multistage condensing steam turbine and a TES subsystem with a separate power conversion loop was defined. Conceptual designs for a 100 MW sub e TES peaking system providing steam at 316 C, 427 C, and 454 C (600 F, 800 F, and 850 F) at 3.79 million Pa (550 psia) were developed and evaluated. Areas requiring further investigation have also been identified.

  10. Modeling thermally active building components using space mapping

    DEFF Research Database (Denmark)

    Pedersen, Frank; Weitzmann, Peter; Svendsen, Svend

    2005-01-01

    In order to efficiently implement thermally active building components in new buildings, it is necessary to evaluate the thermal interaction between them and other building components. Applying parameter investigation or numerical optimization methods to a differential-algebraic (DAE) model....... This paper describes the principle of the space mapping technique, and introduces a simple space mapping technique. The technique is applied to a lumped parameter model of a thermo active component, which provides a model of the thermal performance of the component as a function of two design parameters...... of a building provides a systematic way of estimating efficient building designs. However, using detailed numerical calculations of the components in the building is a time consuming process, which may become prohibitive if the DAE model is to be used for parameter variation or optimization. Unfortunately...

  11. Thermal energy storage in the form of heat or cold with using of the PCM-based accumulation panels

    Directory of Open Access Journals (Sweden)

    Skovajsa Jan

    2016-01-01

    Full Text Available This article describes the usage of thermal energy storage in the form of heat and cold with an adaptation of the special device which is composed of the thermal panels. These panels are based on the phase change materials (PCM for normal inner environment temperature in buildings. The energy for the thermal energy storage is possible to get from built-in electric heating foil or from the tube heat exchanger, which is build in the thermal panels. This technology is able to use renewable energy sources, for example, solar thermal collectors and air-to-water heat pump as a source of heat for heating of the hot water tank. In the cooling mode, there is able to use the heat pump or photovoltaics panels in combination with thermoelectric coolers for cooling.

  12. Finite element analysis of thermal stresses in optical storage media

    Science.gov (United States)

    Evans, K. E.; Nkansah, M. A.; Abbott, S. J.

    1988-10-01

    Finite element techniques are used to calculate the thermal stresses generated in single-layer, optical storage thin films. The calculations predict that the thermal stresses generated by laser heating may reach values well beyond the strength of the media in times much less than that for pit formation by melting. Both dye-polymer and metal-based systems are considered with either air or substrate incident laser sources.

  13. Thermal and acoustic environmental requirements for green buildings in Malaysia

    Directory of Open Access Journals (Sweden)

    Sreenivasaiah Purushothama Rao

    2012-12-01

    Full Text Available Passive design concepts as a strategy for achieving energy efficiency as well as optimum indoor thermal comfort in workspaces are being increasingly applied with the increased awareness of Green Buildings. The challenging task for the building designers in the hot-humid tropics is the provision of indoor thermal comfort for the occupants of the building while reducing energy consumption in the office spaces. Acoustic quality is also an important element in ensuring a healthy working environment. One of the aims of a green building is to minimise its impact on health and performance of the occupants of the building. This has been emphasized in most green building rating systems under requirements for Indoor Environmental Quality (IEQ, highlighting the four main points for achieving an improved indoor environment, viz., indoor air quality, acoustics, visual comfort (lighting and thermal comfort. Although acoustics was mentioned in the IEQ criteria, according to previous surveys and studies acoustic quality in green buildings are not improving. Acoustics performance is bound to be relegated unless it is considered early in design stage. This paper makes an attempt at how green building design strategies contribute to the degradation of acoustical environment in green office buildings. The design strategies implemented to cater for green building requirements such as provision of natural ventilation, daylight, reduction of finishes and office layout leads to an unintended decrease in the acoustical quality. This needs to be addressed and corrected by the building professionals.

  14. Characterization of Inlet Diffuser Performance for Stratified Thermal Storage

    Science.gov (United States)

    Cimbala, John M.; Bahnfleth, William; Song, Jing

    1999-11-01

    Storage of sensible heating or cooling capacity in stratified vessels has important applications in central heating and cooling plants, power production, and solar energy utilization, among others. In stratified thermal storage systems, diffusers at the top and bottom of a stratified tank introduce and withdraw fluid while maintaining a stable density gradient and causing as little mixing as possible. In chilled water storage applications, mixing during the formation of the thermocline near an inlet diffuser is the single greatest source of thermal losses. Most stratified chilled water storage tanks are cylindrical vessels with diffusers that are either circular disks that distribute flow radially outward or octagonal rings of perforated pipe that distribute flow both inward and outward radially. Both types produce gravity currents that are strongly influenced by the inlet Richardson number, but the significance of other parameters is not clear. The present investigation considers the dependence of the thermal performance of a perforated pipe diffuser on design parameters including inlet velocity, ambient and inlet fluid temperatures, and tank dimensions for a range of conditions representative of typical chilled water applications. Dimensional analysis is combined with a parametric study using results from computational fluid dynamics to obtain quantitative relationships between design parameters and expected thermal performance.

  15. Combination of aquifer thermal energy storage and enhanced bioremediation

    NARCIS (Netherlands)

    Ni, Zhuobiao; Gaans, van Pauline; Smit, Martijn; Rijnaarts, Huub; Grotenhuis, Tim

    2016-01-01

    To meet the demand for sustainable energy, aquifer thermal energy storage (ATES) is widely used in the subsurface in urban areas. However, contamination of groundwater, especially with chlorinated volatile organic compounds (CVOCs), is often being encountered. This is commonly seen as an impedime

  16. Thermal energy storage. Citations from the NTIS data base

    Science.gov (United States)

    Cavagnaro, D. M.

    1980-09-01

    The cited reports of federally-funded research concern thermal energy storage. The citations cover the design of equipment, performance evaluation, theory, materials used, and experimental design. This updated bibliography contains 240 citations, 128 of which are new entries to the previous edition.

  17. High Density Thermal Energy Storage with Supercritical Fluids

    Science.gov (United States)

    Ganapathi, Gani B.; Wirz, Richard

    2012-01-01

    A novel approach to storing thermal energy with supercritical fluids is being investigated, which if successful, promises to transform the way thermal energy is captured and utilized. The use of supercritical fluids allows cost-affordable high-density storage with a combination of latent heat and sensible heat in the two-phase as well as the supercritical state. This technology will enhance penetration of several thermal power generation applications and high temperature water for commercial use if the overall cost of the technology can be demonstrated to be lower than the current state-of-the-art molten salt using sodium nitrate and potassium nitrate eutectic mixtures.

  18. Transwall: A modular visually transmitting thermal storage wall

    Science.gov (United States)

    McClelland, J. F.; Mercer, R. W.; Hodges, L.; Szydlowski, R. F.; Sidles, P. H.; Struss, R. G.; Hull, J. R.; Block, D. A.

    1980-12-01

    The Transwall a semitransparent thermal storage wall system that offers a number of advantages over conventional direct gain and Trombe wall approaches is examined. Progress is reported in the design, fabrication, installation, and operation of a glass and aluminum prototype system. A facility for year round performance testing of the system is described and preliminary summer season thermal test data are presented. Thermal performance modeing results that predict heat loss reduction with a heat mirror coating on Transwall to be comparable to that obtained with R6 night insulation are reported.

  19. A Thermal Simulation Tool for Building and Its Interoperability through the Building Information Modeling (BIM Platform

    Directory of Open Access Journals (Sweden)

    Christophe Nicolle

    2013-05-01

    Full Text Available This paper describes potential challenges and opportunities for using thermal simulation tools to optimize building performance. After reviewing current trends in thermal simulation, it outlines major criteria for the evaluation of building thermal simulation tools based on specifications and capabilities in interoperability. Details are discussed including workflow of data exchange of multiple thermal analyses such as the BIM-based application. The present analysis focuses on selected thermal simulation tools that provide functionalities to exchange data with other tools in order to obtain a picture of its basic work principles and to identify selection criteria for generic thermal tools in BIM. Significances and barriers to integration design with BIM and building thermal simulation tools are also discussed.

  20. Thermal management technology for hydrogen storage: Fullerene option

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.C.; Chen, F.C.; Murphy, R.W. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    Fullerenes are selected as the first option for investigating advanced thermal management technologies for hydrogen storage because of their potentially high volumetric and gravimetric densities. Experimental results indicate that about 6 wt% of hydrogen (corresponding to C{sub 60}H{sub 48}) can be added to and taken out of fullerenes. A model assuming thermally activated hydrogenation and dehydrogenation processes was developed to explain the experimental findings. The activation energies were estimated to be 100 and 160 kJ/mole (1.0 and 1.6 eV/H{sub 2}) for the hydrogenation and dehydrogenation processes, respectively. The difference is interpreted as the heat released during hydrogenation. There are indications that the activation energies and the heat of hydrogenation can be modified by the use of catalysts. Preliminary hydrogen storage simulations for a conceptually simple device were performed. A 1-m long hollow metal cylinder with an inner diameter of 0.02 m was assumed to be filled with fullerene powders. The results indicate that the thermal diffusivity of the fullerenes controls the hydrogenation and dehydrogenation rates. The rates can be significantly modified by changing the thermal diffusivity of the material inside the cylinder, e.g., by incorporating a metal mesh. Results from the simulation suggest that thermal management is essential for efficient hydrogen storage devices using fullerenes. While the preliminary models developed in this study explain some of the observation, more controlled experiments, rigorous model development, and physical property determinations are needed for the development of practical hydrogen storage devices. The use of catalysts to optimize the hydrogen storage characteristics of fullerenes also needs to be pursued. Future cooperative work between Oak Ridge National Laboratory (ORNL) and Material & Electrochemical Research Corporation (MER) is planned to address these needs.

  1. Thermal energy storage for the Stirling engine powered automobile

    Science.gov (United States)

    Morgan, D. T. (Editor)

    1979-01-01

    A thermal energy storage (TES) system developed for use with the Stirling engine as an automotive power system has gravimetric and volumetric storage densities which are competitive with electric battery storage systems, meets all operational requirements for a practical vehicle, and can be packaged in compact sized automobiles with minimum impact on passenger and freight volume. The TES/Stirling system is the only storage approach for direct use of combustion heat from fuel sources not suitable for direct transport and use on the vehicle. The particular concept described is also useful for a dual mode TES/liquid fuel system in which the TES (recharged from an external energy source) is used for short duration trips (approximately 10 miles or less) and liquid fuel carried on board the vehicle used for long duration trips. The dual mode approach offers the potential of 50 percent savings in the consumption of premium liquid fuels for automotive propulsion in the United States.

  2. Solar Thermal Energy Storage in a Photochromic Macrocycle.

    Science.gov (United States)

    Vlasceanu, Alexandru; Broman, Søren L; Hansen, Anne S; Skov, Anders B; Cacciarini, Martina; Kadziola, Anders; Kjaergaard, Henrik G; Mikkelsen, Kurt V; Nielsen, Mogens Brøndsted

    2016-07-25

    The conversion and efficient storage of solar energy is recognized to hold significant potential with regard to future energy solutions. Molecular solar thermal batteries based on photochromic systems exemplify one possible technology able to harness and apply this potential. Herein is described the synthesis of a macrocycle based on a dimer of the dihydroazulene/vinylheptafulvene (DHA/VHF) photo/thermal couple. By taking advantage of conformational strain, this DHA-DHA macrocycle presents an improved ability to absorb and store incident light energy in chemical bonds (VHF-VHF). A stepwise energy release over two sequential ring-closing reactions (VHF→DHA) combines the advantages of an initially fast discharge, hypothetically addressing immediate energy consumption needs, followed by a slow process for consistent, long-term use. This exemplifies another step forward in the molecular engineering and design of functional organic materials towards solar thermal energy storage and release.

  3. Thermal energy storage and the passive house standard : how PCM incorporated into wallboard can aid thermal comfort

    Energy Technology Data Exchange (ETDEWEB)

    Colclough, S.; Griffiths, P. [Ulster Univ., Jordanstown, Newtownabbey, Northern Ireland (United Kingdom); Gschwander, S. [Fraunhofer Inst., Freiburg (Germany)

    2009-07-01

    As a thermal storage medium, phase change materials (PCMs) can achieve excellent results when used as an aide to cooling in the summer within a lightweight building envelope. This paper examined an aspect of Climate Specific Building Design by focusing on the effect of PCM wallboard in the context of passive house standards for various climates. The paper is part of a broader study into thermal energy storage in houses with passive energy systems. The effect of PCM wallboard on indoor temperatures was examined for several European locations using the Dynamic Building Simulation tool. Cooling effects of up to 3 degrees C and reduced overheating hours of up to 18 per cent were predicted for locations such as Athens, Greece. Yet, the PCM wallboard was found to be ineffective in temperate locations such as Belfast. The study showed that the effectiveness of the wallboard is climate dependent and that care must be taken to select the most appropriate phase change temperature. 9 refs., 1 tab., 17 figs.

  4. Combining building thermal simulation methods and LCA methods

    DEFF Research Database (Denmark)

    Pedersen, Frank; Hansen, Klaus; Wittchen, Kim Bjarne

    2008-01-01

    Thsi paper describes recent efforts made by the Danish Building Research Institute regarding the integration of a life cycle assessment (LCA) method into a whole building hygro-thermal simulation tool. The motivation for the work is that the increased requirements to the energy performance...

  5. Effect of heat and moisture transport and storage properties of building stones on the hygrothermal performance of historical building envelopes

    Science.gov (United States)

    KoÅáková, Dana; Kočí, Václav; Žumár, Jaromír; Keppert, Martin; Holčapek, Ondřej; Vejmelková, Eva; Černý, Robert

    2016-12-01

    The heat and moisture transport and storage parameters of three different natural stones used on the Czech territory since medieval times are determined experimentally, together with the basic physical properties and mechanical parameters. The measured data are applied as input parameters in the computational modeling of hygrothermal performance of building envelopes made of the analyzed stones. Test reference year climatic data of three different locations within the Czech Republic are used as boundary conditions on the exterior side. Using the simulated hygric and thermal performance of particular stone walls, their applicability is assessed in a relation to the geographical and climatic conditions. The obtained results indicate that all three investigated stones are highly resistant to weather conditions, freeze/thaw cycles in particular.

  6. Duct thermal performance models for large commercial buildings

    Energy Technology Data Exchange (ETDEWEB)

    Wray, Craig P.

    2003-10-01

    Despite the potential for significant energy savings by reducing duct leakage or other thermal losses from duct systems in large commercial buildings, California Title 24 has no provisions to credit energy-efficient duct systems in these buildings. A substantial reason is the lack of readily available simulation tools to demonstrate the energy-saving benefits associated with efficient duct systems in large commercial buildings. The overall goal of the Efficient Distribution Systems (EDS) project within the PIER High Performance Commercial Building Systems Program is to bridge the gaps in current duct thermal performance modeling capabilities, and to expand our understanding of duct thermal performance in California large commercial buildings. As steps toward this goal, our strategy in the EDS project involves two parts: (1) developing a whole-building energy simulation approach for analyzing duct thermal performance in large commercial buildings, and (2) using the tool to identify the energy impacts of duct leakage in California large commercial buildings, in support of future recommendations to address duct performance in the Title 24 Energy Efficiency Standards for Nonresidential Buildings. The specific technical objectives for the EDS project were to: (1) Identify a near-term whole-building energy simulation approach that can be used in the impacts analysis task of this project (see Objective 3), with little or no modification. A secondary objective is to recommend how to proceed with long-term development of an improved compliance tool for Title 24 that addresses duct thermal performance. (2) Develop an Alternative Calculation Method (ACM) change proposal to include a new metric for thermal distribution system efficiency in the reporting requirements for the 2005 Title 24 Standards. The metric will facilitate future comparisons of different system types using a common ''yardstick''. (3) Using the selected near-term simulation approach

  7. Portuguese thermal building legislation and stategies for the future

    OpenAIRE

    Gonçalves, Helder; Panão, Marta Oliveira; Camelo, Susana

    2010-01-01

    Portugal must evaluate, according to the Energu Performance Building Directive, the national requirements for energy performance of new buildings until 2011, which can be an opportunity to devise a national stretegy that tightens the minimum energy performance requirements. The present study intends to analyze the changes that should be introduced in the Portuguese Regulation to achieve highl energy efficient buildings. The objective consists on evaluating the relevant improvement of thermal ...

  8. Thermally activated building systems in context of increasing building energy efficiency

    Directory of Open Access Journals (Sweden)

    Stojanović Branislav V.

    2014-01-01

    Full Text Available One of the possible ways to provide heating to the building is to use thermally activated building systems. This type of heating, besides providing significant increase in building energy efficiency, allows using low-temperature heating sources. In this paper, special attention is given to opaque part of the building façade with integrated thermally activated building systems. Due to fact that this type of system strongly depends on temperature of this construction-thermal element and type and thickness of other materials of the façade, influence of these parameters on energy efficiency was analyzed in this paper. Since the simplest and most promising way of using geothermal energy is to use it directly, for our analysis this source of energy was selected. Building energy needs for heating were obtained for real residential multi-family building in Serbia by using EnergyPlus software. The building with all necessary input for simulation was modeled in Google SketchUp with aid of Open Studio Plug-in. Obtained results were compared with measured heating energy consumption. The results show that thermally activated building systems represent good way to increase building energy efficiency and that applying certain temperatures within this element, low-energy house standard can be achieved.

  9. Thermal reservoir sizing for adiabatic compressed air energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Kere, Amelie; Goetz, Vincent; Py, Xavier; Olives, Regis; Sadiki, Najim [Perpignan Univ. (France). PROMES CNRS UPR 8521; Mercier-Allart, Eric [EDF R et D, Chatou (France)

    2012-07-01

    Despite the operation of the two existing industrial facilities to McIntosh (Alabama), and for more than thirty years, Huntorf (Germany), electricity storage in the form of compressed air in underground cavern (CAES) has not seen the development that was expected in the 80s. The efficiency of this form of storage was with the first generation CAES, less than 50%. The evolving context technique can significantly alter this situation. The new generation so-called Adiabatic CAES (A-CAES) is to retrieve the heat produced by the compression via thermal storage, thus eliminating the necessity of gas to burn and would allow consideration efficiency overall energy of the order of 70%. To date, there is no existing installation of A-CAES. Many studies describe the principal and the general working mode of storage systems by adiabatic compression of air. So, efficiencies of different configurations of adiabatic compression process were analyzed. The aim of this paper is to simulate and analyze the performances of a thermal storage reservoir integrated in the system and adapted to the working conditions of a CAES.

  10. Power Admission Control with Predictive Thermal Management in Smart Buildings

    DEFF Research Database (Denmark)

    Yao, Jianguo; Costanzo, Giuseppe Tommaso; Zhu, Guchuan

    2015-01-01

    This paper presents a control scheme for thermal management in smart buildings based on predictive power admission control. This approach combines model predictive control with budget-schedulability analysis in order to reduce peak power consumption as well as ensure thermal comfort. First...

  11. Foam/Aerogel Composite Materials for Thermal and Acoustic Insulation and Cryogen Storage

    Science.gov (United States)

    Williams, Martha K. (Inventor); Smith, Trent M. (Inventor); Fesmire, James E. (Inventor); Weiser, Erik S. (Inventor); Sass, Jared P. (Inventor)

    2011-01-01

    The invention involves composite materials containing a polymer foam and an aerogel. The composite materials have improved thermal insulation ability, good acoustic insulation, and excellent physical mechanical properties. The composite materials can be used, for instance, for heat and acoustic insulation on aircraft, spacecraft, and maritime ships in place of currently used foam panels and other foam products. The materials of the invention can also be used in building construction with their combination of light weight, strength, elasticity, ability to be formed into desired shapes, and superior thermal and acoustic insulation power. The materials have also been found to have utility for storage of cryogens. A cryogenic liquid or gas, such as N.sub.2 or H.sub.2, adsorbs to the surfaces in aerogel particles. Thus, another embodiment of the invention provides a storage vessel for a cryogen.

  12. Synthesis and thermal energy storage properties of erythritol tetrastearate and erythritol tetrapalmitate

    Energy Technology Data Exchange (ETDEWEB)

    Sari, A.; Eroglu, R.; Bicer, A.; Karaipekli, A. [Gaziosmanpasa University, Department of Chemistry, Tokat (Turkey)

    2011-01-15

    Erythritol tetrapalmitate (ETP) and erythritol tetrastearate (ETS) were synthesized as novel solid-liquid phase change materials (PCM) by means of the direct esterification reaction of the erythritol with palmitic and stearic acids. The ETP and ETS esters were characterized chemically using FT-IR and {sup 1}H NMR techniques. The energy storage properties of the esters were determined by DSC analysis. The results indicated that the ETP and ETS esters synthesized as novel solid-liquid PCMs are promising materials for thermal energy storage applications at large scale such as solar energy storage, building heating or cooling, indoor temperature controlling, and production of smart textile and insulation clothing. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. An experimental study of enhanced heat transfer in rectangular PCM thermal storage

    Energy Technology Data Exchange (ETDEWEB)

    Stritih, U. [University of Ljubljana (Slovenia). Faculty of Mechanical Engineering

    2004-06-01

    The heat-transfer characteristics of a latent-heat storage unit with a finned surface have been experimentally studied in terms of the solidification and melting processes by comparing them with those of a heat-storage unit with a plain surface. Paraffin with a melting point of 30{sup o}C was used in the investigations because it is appropriate for thermal storage applications in buildings. Time-based variations of the temperature distributions and heat flux are explained from the results of observations of the melting and the solidification layers. The dimensionless Nusselt number was calculated as a function of the Rayleigh number for natural convection in the paraffin for both the melting and the solidification processes. The effectiveness of the fins was calculated from the quotient of the heat flux with fins and the heat flux without fins. (author)

  14. Thermal energy storage using phase change materials fundamentals and applications

    CERN Document Server

    Fleischer, Amy S

    2015-01-01

    This book presents a comprehensive introduction to the use of solid‐liquid phase change materials to store significant amounts of energy in the latent heat of fusion. The proper selection of materials for different applications is covered in detail, as is the use of high conductivity additives to enhance thermal diffusivity. Dr. Fleischer explores how applications of PCMS have expanded over the past 10 years to include the development of high efficiency building materials to reduce heating and cooling needs, smart material design for clothing, portable electronic systems thermal management, solar thermal power plant design and many others. Additional future research directions and challenges are also discussed.

  15. Thermal Comfort and Ventilation Criteria for low Energy Residential Buildings in Building Codes

    DEFF Research Database (Denmark)

    Cao, Guangyu; Kurnitski, Jarek; Awbi, Hazim;

    2012-01-01

    Indoor environmental quality and energy performance of buildings are becoming more and more important in the design and construction of low energy, passive and zero energy buildings. At the same time, improved insulation and air tightness have the potential to resulting in a deterioration...... of the indoor air quality in such buildings. Currently, there are no global guidelines for specifying the indoor thermal environment in such low-energy buildings. The objective of this paper is to analyse the classification of indoor thermal comfort levels and recommended ventilation rates for different low...... energy buildings, and propose a set of indices that would enable better quantification and comparison among low energy buildings. In this study, the building codes and voluntary guidelines have been reviewed on the basis of experience of Finland, UK, Denmark, USA and Germany. The analysis in this paper...

  16. Heat Loss Due To Thermal Bridges In Buildings

    Science.gov (United States)

    Fang, J. B.; tarot, R. A.; Childs, K. W.; Courville, G. E.

    1984-03-01

    Building envelopes often contain numerous highly conductive heat flow paths, called thermal bridges, which are major sources of heat loss and deterioration of building materials due to moisture condensation. Some examples of thermal bridges occurring in office buildings are presented. Infrared thermography was used to identify the locations and magnitudes of thermally defective areas resulting from inadequate construction, design, or substandard workmanship in existing buildings. Due to the large thermal inertia of building components and transient conditions caused by fluctuating outdoor and indoor temperatures, long measurement periods are required. This makes thermography impractical for quantifying the heat loss. In order to estimate the heat loss rate from thermal bridges and to obtain a better understanding of the physical processes involved, a two-dimensional heat flow model has been developed for transient heat conduction within the exterior wall/intermediate floor systems. The calculated results from the mathematical model are compared with available experimental data. An in-situ measurement technique, which is currently under development at NBS for quantifying the energy loss due to thermal bridges, is described.

  17. Thermographic measurement of thermal bridges in buildings under dynamic behavior

    Science.gov (United States)

    Ferrarini, G.; Bison, P.; Bortolin, A.; Cadelano, G.; De Carli, M.

    2016-05-01

    The accurate knowledge of the thermal performance could reduce significantly the impact of buildings on global energy consumption. Infrared thermography is widely recognized as one of the key technologies for building surveys, thanks to its ability to acquire at a glance thermal images of the building envelope. However, a spot measurement could be misleading when the building is under dynamic thermal conditions. In this case data should be acquired for hours or days, depending on the thermal properties of the walls. Long term thermographic monitoring are possible but imply strong challenges from a practical standpoint. This work investigates the possibilities and limitations of spot thermographic surveys coupled with contact probes, that are able to acquire continuously the thermal signal for days, to investigate the thermal bridges of a building. The goal is the estimation of the reliability and accuracy of the measurement under realistic environmental conditions. Firstly, numerical simulations are performed to determine the reference value of an experimental case. Then a long term thermographic survey is performed and integrated with the contact probe measurement, assessing the feasibility of the method.

  18. Comparison of advanced thermal and electrical storage for parabolic dish solar thermal power systems

    Science.gov (United States)

    Fujita, T.; Birur, G. C.; Schredder, J. M.; Bowyer, J. M.; Awaya, H. I.

    1982-01-01

    Parabolic dish solar concentrator cluster concepts are explored, with attention given to thermal storage systems coupled to Stirling and Brayton cycle power conversion devices. Sensible heat storage involving molten salt (NaOH), liquid sodium, and solid cordierite bricks are considered for 1500 F thermal storage systems. Latent heat storage with NaF-MgF2 phase change materials are explored in terms of passive, active, and direct contact designs. Comparisons are made of the effectiveness of thermal storage relative to redox, Na-S, Zn-Cl, and Zn-Br battery storage systems. Molten lead trickling down through a phase change eutectic, the NaF-MgF2, formed the direct contact system. Heat transport in all systems is effected through Inconel pipes. Using a cost goal of 120-150 mills/kWh as the controlling parameter, sensible heat systems with molten salts transport with either Stirling or Brayton engines, or latent heat systems with Stirling engines, and latent heat-Brayton engine with direct contact were favored in the analyses. Battery storage systems, however, offered the most flexibility of applications.

  19. Advanced storage concepts for solar and low energy buildings, IEA-SHC Task 32. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, J.M.; Andersen, Elsa; Furbo, S.

    2008-01-15

    This report reports on the results of the activities carried through in connection with the Danish part of the IEA SHC Task 32 project: Advanced Storage Concepts for Solar and Low Energy Buildings. The Danish involvement has focused on Subtask C: Storage Concepts Based on Phase Change Materials and Subtask D: Storage Concepts Based on Advanced Water Tanks and Special Devices. The report describes activities concerning heat-of-fusion storage and advanced water storage. (BA)

  20. Analyzing Control Challenges for Thermal Energy Storage in Foodstuffs

    DEFF Research Database (Denmark)

    Hovgaard, Tobias Gybel; Larsen, Lars F. S.; Skovrup, Morten Juel

    2012-01-01

    We consider two important challenges that arise when thermal energy is to be stored in foodstuffs. We have previously introduced economic optimizing MPC schemes that both reduce operating costs and offer flexible power consumption in a future Smart Grid. The goal is to utilize the thermal capacity...... and for estimating maximum energy storage time. The results are shown for a large range of parameters, and with specific calculations for selected foodstuff items....... of refrigerated goods from available air temperature measurements. This is based on data obtained from a dedicated experiment. Since limits are specified for food temperatures, the estimate is essential for full exploitation of the thermal potential. Secondly, the thermal properties, shapes and sizes of different...

  1. Envelope Thermal Design Optimization for Urban Residential Buildings in Malawi

    Directory of Open Access Journals (Sweden)

    Amos Kalua

    2016-04-01

    Full Text Available This study sought to optimize the envelope thermal design of free-running urban residential buildings in Malawi. It specifically set out to improve the urban residential buildings’ thermal comfort and suggest optimal envelope thermal design features for these buildings. The research study was primarily dependent on computer simulations in EnergyPlus to replicate the typical Malawian urban residential building’s thermal behaviour and then study the impacts of various envelope configurations on the thermal comfort conditions registered in the building. The simulation model was experimentally validated to check its appropriateness to the climatic design conditions prevalent in Malawi and out of the three major cities that were considered, the model was found to be appropriate for use in the two cities of Mzuzu and Lilongwe leaving out the city of Blantyre. The optimization methodology that was employed involved the use of orthogonal arrays, statistical analyses and the listing method. It was found that the optimal envelope thermal design, which registered up to 18% lower discomfort hours than that of the typical urban residential building, consists of a 50 mm concrete floor slab, 230 mm burnt brick walls with an external layer of 19 mm EPS, tiled roof with an internal layer of sarking and 50 mm EPS, double Low-E Glazing with a transparency ratio of 45% and 0.2408 m2 of adaptable operational surface area for the air bricks. Out of all the envelope features that were studied, air infiltration registered the most significant contribution towards the ultimate residential building thermal performance. It was demonstrated that controlled air infiltration through the use of operable air bricks whose operational surface area is adaptable can be very effective in enhancing the building’s comfort levels. It was further observed that excessive insulation of the building envelope generally has a detrimental effect on the indoor space thermal comfort

  2. University of Minnesota aquifer thermal energy storage (ATES) project report on the third long-term cycle

    Energy Technology Data Exchange (ETDEWEB)

    Hoyer, M.C.; Hallgren, J.P.; Uebel, M.H.; Delin, G.N.; Eisenreich, S.J.; Sterling, R.L.

    1994-12-01

    The University of Minnesota aquifer thermal energy storage (ATES) system has been operated as a field test facility (FTF) since 1982. The objectives were to design, construct, and operate the facility to study the feasibility of high-temperature ATES in a confined aquifer. Four short-term and two long-term cycles were previously conducted, which provided a greatly increased understanding of the efficiency and geochemical effects of high-temperature aquifer thermal energy storage. The third long-term cycle (LT3) was conducted to operate the ATES system in conjunction with a real heating load and to further study the geochemical impact that heated water storage had on the aquifer. For LT3, the source and storage wells were modified so that only the most permeable portion, the Ironton-Galesville part, of the Franconia-Ironton-Galesville aquifer was used for storage. This was expected to improve storage efficiency by reducing the surface area of the heated volume and simplify analysis of water chemistry results by reducing the number of aquifer-related variables which need to be considered. During LT3, a total volume of 63.2 {times} 10{sup 3} m {sup 3} of water was injected at a rate of 54.95 m{sup 3}/hr into the storage well at a mean temperature of 104.7{degrees}C. Tie-in to the reheat system of the nearby Animal Sciences Veterinary Medicine (ASVM) building was completed after injection was completed. Approximately 66 percent (4.13 GWh) of the energy added to the aquifer was recovered. Approximately 15 percent (0.64 GWh) of the usable (10 building. Operations during heat recovery with the ASVM building`s reheat system were trouble-free. Integration into more of the ASVM (or other) building`s mechanical systems would have resulted in significantly increasing the proportion of energy used during heat recovery.

  3. Nanoparticles for heat transfer and thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Dileep; Cingarapu, Sreeram; Timofeeva, Elena V.; Moravek, Michael

    2015-07-14

    An article of manufacture and method of preparation thereof. The article of manufacture and method of making the article includes an eutectic salt solution suspensions and a plurality of nanocrystalline phase change material particles having a coating disposed thereon and the particles capable of undergoing the phase change which provides increase in thermal energy storage. In addition, other articles of manufacture can include a nanofluid additive comprised of nanometer-sized particles consisting of copper decorated graphene particles that provide advanced thermal conductivity to heat transfer fluids.

  4. An assessment methodology for thermal energy storage evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.R.; Dirks, J.A.; Drost, M.K.; Spanner, G.E.; Williams, T.A.

    1987-11-01

    This report documents an assessment methodology for evaluating the cost, performance, and overall economic feasibility of thermal energy storage (TES) concepts. The methodology was developed by Thermal Energy Storage Evaluation Program personnel at Pacific Northwest Laboratory (PNL) for use by PNL and other TES concept evaluators. The methodology is generically applicable to all TES concepts; however, specific analyses may require additional or more detailed definition of the ground rules, assumptions, and analytical approach. The overall objective of the assessment methodology is to assist in preparing equitable and proper evaluations of TES concepts that will allow developers and end-users to make valid decisions about research and development (R and D) and implementation. The methodology meets this objective by establishing standard approaches, ground rules, assumptions, and definitions that are analytically correct and can be consistently applied by concept evaluators. 15 refs., 4 figs., 13 tabs.

  5. Thermal comfort in residential buildings by the millions

    DEFF Research Database (Denmark)

    Østergård, Torben; Jensen, Rasmus Lund; Maagaard, Steffen

    2016-01-01

    In Danish building code and many design briefings, criteria regarding thermal comfort are defined for “critical” rooms in residential buildings. Identifying the critical room is both difficult and time-consuming for large, multistory buildings. To reduce costs and time, such requirement often...... in most residential buildings. For each room variation, we perform 100.000 simulations while varying important design inputs such as window-floor-ratio, ventilation rates, glazing properties, and shading properties. Prior to this, the Morris method was used to identify and fixate insignificant inputs...

  6. Investigation of thermal storage and steam generator issues

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-01

    A review and evaluation of steam generator and thermal storage tank designs for commercial nitrate salt technology showed that the potential exists to procure both on a competitive basis from a number of qualified vendors. The report outlines the criteria for review and the results of the review, which was intended only to assess the feasibility of each design, not to make a comparison or select the best concept.

  7. Transient thermal NDT and E of defects in building materials

    Science.gov (United States)

    Avdelidis, N. P.; Stavrakas, D.; Moropoulou, A.

    2006-04-01

    In this work, infrared thermography (IRT) was used for the investigation of structural materials using the active approach. Four types of building materials were examined; three types of porous stone (from Rhodes, Cyprus, Rethymno - Crete) and one type of marble (Dionysus). Specimens containing self-induced defects of known dimensions and depths were studied. The samples were heated externally (thermal excitation) and thermograms were recorded continuously at the transient phase. Mathematical - thermal modelling enabling the modelling of the investigated subsurface defects, using the thermocalc 3-D software, was also implemented. Then, quantification analysis (i.e. temperature - time plots, as well as thermal contrast curves) from the experimental tests, as well as from the use of thermal modelling runs took place, indicating the thermal behaviour of building materials containing such defects. The results of this research show that IRT can be used for the detection and quantification of defects in structural materials.

  8. Simulation of diurnal thermal energy storage systems: Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Katipamula, S.; Somasundaram, S. [Pacific Northwest Lab., Richland, WA (United States); Williams, H.R. [Univ. of Alaska, Fairbanks, AK (United States). Dept. of Mechanical Engineering

    1994-12-01

    This report describes the results of a simulation of thermal energy storage (TES) integrated with a simple-cycle gas turbine cogeneration system. Integrating TES with cogeneration can serve the electrical and thermal loads independently while firing all fuel in the gas turbine. The detailed engineering and economic feasibility of diurnal TES systems integrated with cogeneration systems has been described in two previous PNL reports. The objective of this study was to lay the ground work for optimization of the TES system designs using a simulation tool called TRNSYS (TRaNsient SYstem Simulation). TRNSYS is a transient simulation program with a sequential-modular structure developed at the Solar Energy Laboratory, University of Wisconsin-Madison. The two TES systems selected for the base-case simulations were: (1) a one-tank storage model to represent the oil/rock TES system, and (2) a two-tank storage model to represent the molten nitrate salt TES system. Results of the study clearly indicate that an engineering optimization of the TES system using TRNSYS is possible. The one-tank stratified oil/rock storage model described here is a good starting point for parametric studies of a TES system. Further developments to the TRNSYS library of available models (economizer, evaporator, gas turbine, etc.) are recommended so that the phase-change processes is accurately treated.

  9. Simulation of diurnal thermal energy storage systems: Preliminary results

    Science.gov (United States)

    Katipamula, S.; Somasundaram, S.; Williams, H. R.

    1994-12-01

    This report describes the results of a simulation of thermal energy storage (TES) integrated with a simple-cycle gas turbine cogeneration system. Integrating TES with cogeneration can serve the electrical and thermal loads independently while firing all fuel in the gas turbine. The detailed engineering and economic feasibility of diurnal TES systems integrated with cogeneration systems has been described in two previous PNL reports. The objective of this study was to lay the ground work for optimization of the TES system designs using a simulation tool called TRNSYS (TRaNsient SYstem Simulation). TRNSYS is a transient simulation program with a sequential-modular structure developed at the Solar Energy Laboratory, University of Wisconsin-Madison. The two TES systems selected for the base-case simulations were: (1) a one-tank storage model to represent the oil/rock TES system; and (2) a two-tank storage model to represent the molten nitrate salt TES system. Results of the study clearly indicate that an engineering optimization of the TES system using TRNSYS is possible. The one-tank stratified oil/rock storage model described here is a good starting point for parametric studies of a TES system. Further developments to the TRNSYS library of available models (economizer, evaporator, gas turbine, etc.) are recommended so that the phase-change processes is accurately treated.

  10. Study on Tetradecane Nanoemulsion for Thermal Energy Transportation and Storage

    Science.gov (United States)

    Fumoto, Koji; Kawaji, Masahiro; Kawanami, Tsuyoshi

    Phase change emulsion (PCE) is a novel fluid used for heat storage and transfer. It has the following characteristics: higher apparent specific heat and higher heat transfer ability in the phase-change temperature range as compared to the conventional single-phase heat transfer fluids. In particular, oil-in-water (O/W) emulsions are latent heat storage materials that have low melting points, thus offering attractive opportunities for heat transfer enhancement and thermal energy transportation and storage. In this paper, milky white oil-in-water emulsions have been formed using water, Tween 80, Span 80, and tetradecane by low-energy emulsification methods (e.g., the phase inversion temperature (PIT) method). The relations between the component ratios of the emulsions and both the particle diameters and the stability of the resulting emulsions have been determined by dynamic light scattering (DLS) and vibration viscometry. The results show that the apparent viscosity of the nanoemulsion is lower than that of an emulsion, which was prepared with the same mixing ratio of surfactant and concentration of phase change material. Moreover, the surfactant concentration is found to contribute to the stability of the phase change nanoemulsion. Results indicate that the phase change nanoemulsion is a promising material for thermal storage applications.

  11. Improved thermal storage material for portable life support systems

    Science.gov (United States)

    Kellner, J. D.

    1975-01-01

    The availability of thermal storage materials that have heat absorption capabilities substantially greater than water-ice in the same temperature range would permit significant improvements in performance of projected portable thermal storage cooling systems. A method for providing increased heat absorption by the combined use of the heat of solution of certain salts and the heat of fusion of water-ice was investigated. This work has indicated that a 30 percent solution of potassium bifluoride (KHF2) in water can absorb approximately 52 percent more heat than an equal weight of water-ice, and approximately 79 percent more heat than an equal volume of water-ice. The thermal storage material can be regenerated easily by freezing, however, a lower temperature must be used, 261 K as compared to 273 K for water-ice. This work was conducted by the United Aircraft Research Laboratories as part of a program at Hamilton Standard Division of United Aircraft Corporation under contract to NASA Ames Research Center.

  12. Thermal comfort in residential buildings: Sensitivity to building parameters and occupancy

    NARCIS (Netherlands)

    Ioannou, A.; Itard, L.C.M.

    2014-01-01

    Dynamic simulation is widely used for assessing thermal comfort in dwellings. Simulation tools, though, have shortcomings due to false assumptions made during the design phase of buildings, limited information on the building's envelope and installations and misunderstandings over the role of the oc

  13. A method to determine stratification efficiency of thermal energy storage processes independently from storage heat losses

    DEFF Research Database (Denmark)

    Haller, M.Y.; Yazdanshenas, Eshagh; Andersen, Elsa

    2010-01-01

    A new method for the calculation of a stratification efficiency of thermal energy storages based on the second law of thermodynamics is presented. The biasing influence of heat losses is studied theoretically and experimentally. Theoretically, it does not make a difference if the stratification...... process is in agreement with the first law of thermodynamics. A comparison of the stratification efficiencies obtained from experimental results of charging, standby, and discharging processes gives meaningful insights into the different mixing behaviors of a storage tank that is charged and discharged...

  14. Thermal Storage Systems Assessment for Energy Sustainability in Housing Units

    Directory of Open Access Journals (Sweden)

    Tania I. Lagunes Vega

    2016-04-01

    Full Text Available In order to achieve greater enhancements in energy sustainability for housing, the function and efficiency of two different passive cooling systems were studied: encapsulated water in recycled bottles of Polyethylene terephthalate (PET and polystyrene plates, in comparison with standard concrete slab systems, which are customarily used in housing. Experiments were placed over a tile surface, in which temperature changes were monitored for a period of 20 days from 08:00 to 20:00. The efficiency of passive thermal storage systems was endorsed through statistical analysis using the “SPSS” software. This resulted in a 17% energy saving, thus promoting energy sustainability in housing units, which reduces the use of electrical appliances required to stabilize conditions to achieve optimum thermal comfort for the human body inside a house, therefore, reducing electrical power consumption, CO2 emissions to the atmosphere and generating savings. Due to the complexity of a system with temperature changes, a fractal analysis was performed for each experimental system, using the “Benoit” software (V.1.3 with self-compatible tools of rescaled range (R/S and a wavelets method, showing that the thermal fluctuations on the tiles with the thermal storage system adapt to the rescaled range analysis and the regular tiles adapt to the wavelets method.

  15. PCM/ graphite foam composite for thermal energy storage device

    Science.gov (United States)

    Guo, C. X.; Ma, X. L.; Yang, L.

    2015-07-01

    Numerical studies are proposed to predict and investigate the thermal characteristics of a thermal storage device consists of graphite foam matrix saturated with phase change material, PCM. The composite (graphite foam matrix saturated with PCM) is prepared by impregnation method under vacuum condition, and then is introduced into a cylindrical shell and tube device while it experiences its heat from an inner tube fluid. The two-dimensional numerical simulation is performed using the volume averaging technique; while the phases change process is modelled using the enthalpy porosity method. A series of numerical calculations have been done in order to analyze the influence of fluid operating conditions on the melting process of the paraffin/graphite foam. The results are given in terms of temperature or liquid fraction time history in paraffin/graphite foam composite, which show that the heat transfer rate of the device is effectively improved due to the high thermal conductivity of graphite foams. Therefore, paraffin/graphite foam composite can be considered as suitable candidates for latent heat thermal energy storage device.

  16. A thermal design tool for buildings in ground contact

    Energy Technology Data Exchange (ETDEWEB)

    Richards, P.G.; Mathews, E.H. (Pretoria Univ. (South Africa). Centre for Experimental and Numerical Thermoflow)

    1994-01-01

    Simulation of the heat flow into the ground underneath a building is usually performed by means of procedures which do not take into account other heat flow paths. An efficient design tool for buildings in ground contact is lacking. This paper consequently describes how heat flow into the ground can be simplified and incorporated in an efficient design tool. The design tool is based on a first order thermal model calculated by means of straightforward equations. Other features of the design tool include the simulation of multizone behaviour, comfort temperatures, time dependent thermal parameters such as variable ventilation as well as alternative air-conditioning systems such as evaporative and structural cooling. The proposed simulation of ground contact is validated in 53 existing buildings comprising a wide range of thermal characteristics. (Author)

  17. Eutectic mixtures of some fatty acids for latent heat storage: Thermal properties and thermal reliability with respect to thermal cycling

    Energy Technology Data Exchange (ETDEWEB)

    Sari, Ahmet [Department of Chemistry, Gaziosmanpasa University, 60240 Tokat (Turkey)]. E-mail: asari@gop.edu.tr

    2006-06-15

    Accelerated thermal cycle tests have been conducted to study the change in melting temperatures and latent heats of fusion of the eutectic mixtures of lauric acid (LA)-myristic acid (MA), lauric acid (LA)-palmitic acid (PA) and myristic acid (MA)-stearic acid (SA) as latent heat storage materials. The thermal properties of these materials were determined by the differential scanning calorimetry (DSC) analysis method. The thermal reliability of the eutectic mixtures after melt/freeze cycles of 720, 1080 and 1460 was also evaluated using the DSC curves. The accelerated thermal cycle tests indicate that the melting temperatures usually tend to decrease, and the variations in the latent heats of fusion are irregular with increasing number of thermal cycles. Moreover, the probable reasons for the change in thermal properties of the eutectic mixtures after repeated thermal cycles were investigated. Fourier Transform Infrared (FT-IR) spectroscopic analysis indicates that the accelerated melt/freeze processes do not cause any degradation in the chemical structure of the mixtures. The change in thermal properties of the eutectic mixtures with increasing number of thermal cycles is only because of the presence of certain amounts of impurities in the fatty acids used in their preparation. It is concluded that the tested eutectic mixtures have reasonable thermal properties and thermal reliability as phase change materials (PCMs) for latent heat storage in any solar heating applications that include a four year utilization period.

  18. Influence of Building Envelope Thermal Mass on Heating Design Temperature

    Science.gov (United States)

    Gaujena, B.; Borodinecs, A.; Zemitis, J.; Prozuments, A.

    2015-11-01

    The stability of indoor air parameters is a very important factor, essential for such institutions as museums, schools and hospitals. Nowadays the use of renewable energy for space heating became one of the top priorities in modern building design. The active and passive solar energy as well as heat pumps are widely used nowadays. However, such technologies have a limitation in cold climates and often are not able to cover maximal heating loads. This paper is devoted to analysis of influence of building envelope's properties and outdoor air parameters on indoor air thermodynamic parameters stability in winter time. It presents analysis of thermal mass impact on building energy performance and indoor air parameter stability in cold climate. The results show that the thermal mass of building envelope is able to cover extreme winter temperatures as well as in case of emergency heat supply break.

  19. From rice husk to high performance shape stabilized phase change materials for thermal energy storage

    DEFF Research Database (Denmark)

    Mehrali, Mohammad; Latibari, Sara Tahan; Rosen, Marc A.

    2016-01-01

    exceptional phase change behavior, having a desirable latent heat storage capacity of 175 kJ kg(-1). When exposed to high solar radiation intensities, the composites can absorb and store the thermal energy. An FTIR analysis of the SSPCMs indicated that there was no chemical interaction between the palmitic...... and excellent reversibility. The prepared SSPCMs with enhanced heat transfer and phase change properties provide a beneficial option for building energy conservation and solar energy applications owing to the low cost of raw materials and the simple synthetic technique....

  20. Solar-thermal conversion and thermal energy storage of graphene foam-based composites

    Science.gov (United States)

    Zhang, Lianbin; Li, Renyuan; Tang, Bo; Wang, Peng

    2016-07-01

    Among various utilizations of solar energy, solar-thermal conversion has recently gained renewed research interest due to its extremely high energy efficiency. However, one limiting factor common to all solar-based energy conversion technologies is the intermittent nature of solar irradiation, which makes them unable to stand-alone to satisfy the continuous energy need. Herein, we report a three-dimensional (3D) graphene foam and phase change material (PCM) composite for the seamlessly combined solar-thermal conversion and thermal storage for sustained energy release. The composite is obtained by infiltrating the 3D graphene foam with a commonly used PCM, paraffin wax. The high macroporosity and low density of the graphene foam allow for high weight fraction of the PCM to be incorporated, which enhances the heat storage capacity of the composite. The interconnected graphene sheets in the composite provide (1) the solar-thermal conversion capability, (2) high thermal conductivity and (3) form stability of the composite. Under light irradiation, the composite effectively collects and converts the light energy into thermal energy, and the converted thermal energy is stored in the PCM and released in an elongated period of time for sustained utilization. This study provides a promising route for sustainable utilization of solar energy.Among various utilizations of solar energy, solar-thermal conversion has recently gained renewed research interest due to its extremely high energy efficiency. However, one limiting factor common to all solar-based energy conversion technologies is the intermittent nature of solar irradiation, which makes them unable to stand-alone to satisfy the continuous energy need. Herein, we report a three-dimensional (3D) graphene foam and phase change material (PCM) composite for the seamlessly combined solar-thermal conversion and thermal storage for sustained energy release. The composite is obtained by infiltrating the 3D graphene foam with a

  1. Thermal Analysis of a Dry Storage Concept for Capsule Dry Storage Project

    Energy Technology Data Exchange (ETDEWEB)

    JOSEPHSON, W S

    2003-09-04

    There are 1,936 cesium (Cs) and strontium (Sr) capsules stored in pools at the Waste Encapsulation and Storage Facility (WESF). These capsules will be moved to dry storage on the Hanford Site as an interim measure to reduce risk. The Cs/Sr Capsule Dry Storage Project is conducted under the assumption that the capsules will eventually be moved to the repository at Yucca Mountain, and the design criteria include requirements that will facilitate acceptance at the repository. The storage system must also permit retrieval of capsules in the event that vitrification of the capsule contents is pursued. The Capsule Advisory Panel (CAP) was created by the Project Manager for the Hanford Site Capsule Dry Storage Project (CDSP). The purpose of the CAP is to provide specific technical input to the CDSP; to identify design requirements; to ensure design requirements for the project are conservative and defensible; to identify and resolve emerging, critical technical issues, as requested; and to support technical reviews performed by regulatory organizations, as requested. The CAP will develop supporting and summary documents that can be used as part of the technical and safety bases for the CDSP. The purpose of capsule dry storage thermal analysis is to: (1) Summarize the pertinent thermal design requirements sent to vendors, (2) Summarize and address the assumptions that underlie those design requirements, (3) Demonstrate that an acceptable design exists that satisfies the requirements, (4) Identify key design features and phenomena that promote or impede design success, (5) Support other CAP analyses such as corrosion and integrity evaluations, and (6) Support the assessment of proposed designs. It is not the purpose of this report to optimize or fully analyze variations of postulated acceptable designs. The present evaluation will indicate the impact of various possible design features, but not systematically pursue design improvements obtainable through analysis

  2. Experimental study of passive cooling of building facade using phase change materials to increase thermal comfort in buildings in hot humid areas

    Directory of Open Access Journals (Sweden)

    A. A. Madhumathi, B. M.C. Sundarraja

    2012-01-01

    Full Text Available Storage of cooler night temperatures using Phase Change Material (PCM energy storage technique, for cooling of ambient air during hot day times can be an alternate of current cooling techniques in building sector. This work presents the results of an experimental set-up to test energy saving potential of phase change materials with typical construction materials in building facade in Hot-Humid Climatic Regions in real conditions. The main objective of this research is to demonstrate experimentally that it is possible to improve the thermal comfort and reduce the energy consumption of a building without substantial increase in the weight of the construction materials with the inclusion of PCM. This research was conducted to study and evaluate the performance of the existing materials integrated with Organic PCM Polyethylene glycol (PEG E600. This research suggested that the heat gain is significantly reduced when the PCM is incorporated into the brick (conventional building material.

  3. Residential building thermal performance energy efficiency in Yangtze River basin

    Institute of Scientific and Technical Information of China (English)

    王厚华; 庄燕燕; 吴伟伟

    2009-01-01

    Using energy consumption software VisualDOE4.0,simulation was carried out on the energy consumption of a typical residential building in Yangtze River basin,with a focus on thermal performance of envelope each component and application of total heating recovery equipment. The effects of thermal performance of building envelope each component on energy efficiency ratio were analyzed. Comprehensive measures schemes of energy saving were designed by the orthogonal experiment. The energy efficiency ratios of different envelopes combination schemes were gained. Finally,the optimize combination scheme was confirmed. With the measurement dates,the correctness of the simulation dates was completely verified.

  4. Importance of thermal comfort for library building in Kuching, Sarawak

    Directory of Open Access Journals (Sweden)

    S.H. Ibrahim, A. Baharun, M.D. Abdul Mannan, D.A. Abang Adenan

    2013-01-01

    Full Text Available Malaysian Government takes an initiative to provide library in housing areas to improve the quality of human capital. However, the government has to evaluate every aspect of their provision to ensure the services provided meet the demands of the users, including the aspect of thermal comfort in the building. For this study, a library constructed using Industrialised Building System (IBS are selected for thermal comfort evaluation. The data were analyzed using Corrected Effective Temperature (CET index. From the data analysis, it shows that thermal comfort in the library could not be achieved most of the time unless when the mechanical cooling is used. A series of technical design improvements are then recommended to improve the thermal comfort inside the library by incorporating construction details without increasing the cost.

  5. Importance of thermal comfort for library building in Kuching, Sarawak

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, S.H.; Baharun, A.; Abdul Mannan, M.D.; Abang Adenan, D.A. [Department of Civil Engineering, Faculty of Engineering, University Malaysia Sarawak (UNIMAS), 94300 Kota Samarahan, Sarawak (Malaysia)

    2013-07-01

    Malaysian Government takes an initiative to provide library in housing areas to improve the quality of human capital. However, the government has to evaluate every aspect of their provision to ensure the services provided meet the demands of the users, including the aspect of thermal comfort in the building. For this study, a library constructed using Industrialised Building System (IBS) are selected for thermal comfort evaluation. The data were analyzed using Corrected Effective Temperature (CET) index. From the data analysis, it shows that thermal comfort in the library could not be achieved most of the time unless when the mechanical cooling is used. A series of technical design improvements are then recommended to improve the thermal comfort inside the library by incorporating construction details without increasing the cost.

  6. Preparation, characterization, and thermal properties of microencapsulated phase change material for thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Alkan, Cemil; Sari, Ahmet; Karaipekli, Ali [Department of Chemistry, Gaziosmanpasa University, 60240 Tokat (Turkey); Uzun, Orhan [Department of Physics, Gaziosmanpasa University, 60240 Tokat (Turkey)

    2009-01-15

    This study is focused on the preparation, characterization, and determination of thermal properties of microencapsulated docosane with polymethylmethacrylate (PMMA) as phase change material for thermal energy storage. Microencapsulation of docosane has been carried out by emulsion polymerization. The microencapsulated phase change material (MEPCM) was characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. Thermal properties and thermal stability of MEPCM were measured by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). DSC analysis indicated that the docosane in the microcapsules melts at 41.0 C and crystallizes at 40.6 C. It has latent heats of 54.6 and -48.7 J/g for melting and crystallization, respectively. TGA showed that the MEPCM degraded in three distinguishable steps and had good chemical stability. Accelerated thermal cycling tests also indicated that the MEPCM had good thermal reliability. Based on all these results, it can be concluded that the microencapsulated docosane as MEPCMs have good potential for thermal energy storage purposes such as solar space heating applications. (author)

  7. Thermal comfort and energy-efficient cooling of nonresidential buildings

    CERN Document Server

    Kalz, Doreen

    2014-01-01

    This book supports HVAC planners in reducing the cooling energy demand, improving the indoor environment and designing more cost-effective building concepts. High performance buildings have shown that it is possible to go clearly beyond the energy requirements of existing legislation and obtaining good thermal comfort. However, there is still a strong uncertainty in day-to-day practice due to the lack of legislative regulations for mixed-mode buildings which are neither only naturally ventilated nor fully air-conditioned, but use a mix of different low-energy cooling techniques. Based on the f

  8. Survey of solar thermal energy storage subsystems for thermal/electric applications

    Energy Technology Data Exchange (ETDEWEB)

    Segaser, C. L.

    1978-08-01

    A survey of the current technology and estimated costs of subsystems for storing the thermal energy produced by solar collectors is presented. The systems considered were capable of producing both electricity and space conditioning for three types of loads: a single-family detached residence, an apartment complex of 100 units, and a city of 30,000 residents, containing both single-family residences and apartments. Collector temperatures will be in four ranges: (1) 100 to 250/sup 0/F (used for space heating and single-cycle air conditioners and organic Rankine low-temperature turbines); (2) 300 to 400/sup 0/F (used for dual-cycle air conditioners and low-temperature turbines); (3) 400 to 600/sup 0/F (using fluids from parabolic trough collectors to run Rankine turbines); (4) 800 to 1000/sup 0/F (using fluids from heliostats to run closed-cycle gas turbines and steam Rankine turbines). The solar thermal energy subsystems will require from 60 to 36 x 10/sup 5/ kWhr (2.05 x 10/sup 5/ to 1.23 x 10/sup 10/ Btu) of thermal storage capacity. In addition to sensible heat and latent heat storage materials, several other media were investigated as potential thermal energy storage materials, including the clathrate and semiclathrate hydrates, various metal hydrides, and heat storage based on inorganic chemical reactions.

  9. Thermal Energy Storage in Molten Salts: Overview of Novel Concepts and the DLR Test Facility (TESIS)

    OpenAIRE

    2016-01-01

    At present, two-tank molten salt storage systems are the established commercially available concept for solar thermal power plants. Due to their very low vapour pressure and comparatively high thermal stability, molten salts are preferred as the heat transfer fluid and storage medium. Therefore, the development of alternative, more cost-effective concepts is an important step in making thermal energy storage more competitive for industrial processes and solar thermal applications. The pape...

  10. Thermal energy storage for a space solar dynamic power system

    Science.gov (United States)

    Faget, N. M.; Fraser, W. M., Jr.; Simon, W. E.

    1985-01-01

    In the past, NASA has employed solar photovoltaic devices for long-duration missions. Thus, the Skylab system has operated with a silicon photovoltaic array and a nickel-cadmium electrochemical system energy storage system. Difficulties regarding the employment of such a system for the larger power requirements of the Space Station are related to a low orbit system efficiency and the large weight of the battery. For this reason the employment of a solar dynamic power system (SDPS) has been considered. The primary components of an SDPS include a concentrating mirror, a heat receiver, a thermal energy storage (TES) system, a thermodynamic heat engine, an alternator, and a heat rejection system. The heat-engine types under consideration are a Brayton cycle engine, an organic Rankine cycle engine, and a free-piston/linear-alternator Stirling cycle engine. Attention is given to a system description, TES integration concepts, and a TES technology assessment.

  11. PCM-impregnated polymer microcomposites for thermal energy storage

    Science.gov (United States)

    Stark, Philip

    1990-07-01

    The encapsulation of phase change materials (PCMs) into the micropores of an ordered polymer film was investigated. Paraffin wax and high density polyethylene wax were infiltrated successfully into extruded films of the ordered polymer PBZT by a solvent exchange technique to yield microcomposites with PCM levels on the order of 40 volume percent. These microcomposite films exhibit excellent mechanical stability under cyclic freeze-thaw conditions. However, their thermal energy storage capacities, as characterized by differential scanning calorimetry, decrease significantly following freeze-thaw cycling. It appears that the ultrastructure of the PBZT and the thinness of the film (which results in high cooling rates during freeze-thaw cycling) promote the retention of the amorphous form of the PCM rather than the crystalline form. Since the amorphous form of the PCM does not contribute to the latent heat of fusion, the heat storage capacity of the microcomposite is reduced.

  12. Solar-thermal conversion and thermal energy storage of graphene foam-based composite

    KAUST Repository

    Zhang, Lianbin

    2016-07-11

    Among various utilizations of solar energy, solar-thermal conversion has recently gained renewed research interest due to its extremely high energy efficiency. However, one limiting factor common to all solar-based energy conversion technologies is the intermittent nature of solar irradiation, which makes them unable to stand-alone to satisfy continuous energy need. Herein, we report a three-dimensional (3D) graphene foam and phase change material (PCM) composite for the seamlessly combined solar-thermal conversion and thermal storage for sustained energy release. The composite is obtained by infiltrating the 3D graphene foam with a commonly used PCM, paraffin wax. The high macroporosity and low density of the graphene foam allow for high weight fraction of the PCM to be incorporated, which enhances heat storage capacity of the composite. The interconnected graphene sheets in the composite provide (1) the solar-thermal conversion capability, (2) high thermal conductivity and (3) form stability of the composite. Under light irradiation, the composite effectively collects and converts the light energy into thermal energy, and the converted thermal energy is stored in the PCM and released in an elongated period of time for sustained utilization. This study provides a promising route for sustainable utilization of solar energy.

  13. Solar-thermal conversion and thermal energy storage of graphene foam-based composites.

    Science.gov (United States)

    Zhang, Lianbin; Li, Renyuan; Tang, Bo; Wang, Peng

    2016-08-14

    Among various utilizations of solar energy, solar-thermal conversion has recently gained renewed research interest due to its extremely high energy efficiency. However, one limiting factor common to all solar-based energy conversion technologies is the intermittent nature of solar irradiation, which makes them unable to stand-alone to satisfy the continuous energy need. Herein, we report a three-dimensional (3D) graphene foam and phase change material (PCM) composite for the seamlessly combined solar-thermal conversion and thermal storage for sustained energy release. The composite is obtained by infiltrating the 3D graphene foam with a commonly used PCM, paraffin wax. The high macroporosity and low density of the graphene foam allow for high weight fraction of the PCM to be incorporated, which enhances the heat storage capacity of the composite. The interconnected graphene sheets in the composite provide (1) the solar-thermal conversion capability, (2) high thermal conductivity and (3) form stability of the composite. Under light irradiation, the composite effectively collects and converts the light energy into thermal energy, and the converted thermal energy is stored in the PCM and released in an elongated period of time for sustained utilization. This study provides a promising route for sustainable utilization of solar energy.

  14. Advanced phase change composite by thermally annealed defect-free graphene for thermal energy storage.

    Science.gov (United States)

    Xin, Guoqing; Sun, Hongtao; Scott, Spencer Michael; Yao, Tiankai; Lu, Fengyuan; Shao, Dali; Hu, Tao; Wang, Gongkai; Ran, Guang; Lian, Jie

    2014-09-10

    Organic phase change materials (PCMs) have been utilized as latent heat energy storage and release media for effective thermal management. A major challenge exists for organic PCMs in which their low thermal conductivity leads to a slow transient temperature response and reduced heat transfer efficiency. In this work, 2D thermally annealed defect-free graphene sheets (GSs) can be obtained upon high temperature annealing in removing defects and oxygen functional groups. As a result of greatly reduced phonon scattering centers for thermal transport, the incorporation of ultralight weight and defect free graphene applied as nanoscale additives into a phase change composite (PCC) drastically improve thermal conductivity and meanwhile minimize the reduction of heat of fusion. A high thermal conductivity of the defect-free graphene-PCC can be achieved up to 3.55 W/(m K) at a 10 wt % graphene loading. This represents an enhancement of over 600% as compared to pristine graphene-PCC without annealing at a comparable loading, and a 16-fold enhancement than the pure PCM (1-octadecanol). The defect-free graphene-PCC displays rapid temperature response and superior heat transfer capability as compared to the pristine graphene-PCC or pure PCM, enabling transformational thermal energy storage and management.

  15. Preparation, thermal properties and thermal reliability of microencapsulated n-eicosane as novel phase change material for thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Alkan, Cemil; Sari, Ahmet; Karaipekli, Ali [Department of Chemistry, Gaziosmanpasa University, 60240 Tokat (Turkey)

    2011-01-15

    This study deals with preparation, characterization, thermal properties and thermal reliability of n-eicosane microcapsules as novel phase change material (PCM) for thermal energy storage. The microcapsulated PCMs were prepared by coating n-eicosane with polymethylmethacrylate (PMMA) shell. Fourier transform infrared (FT-IR), scanning electron microscope (SEM) and particle size distribution (PSD) analysis were used to characterize the PMMA/eicosane microcapsules as microcapsulated PCMs. The PSD analysis indicated that the average diameter of microcapsules was found to be 0.70 {mu}m under the stirring speed of 2000 rpm. Thermal properties and thermal reliability of the microcapsules were determined using differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA) methods. From DSC analysis, the melting and freezing temperatures and the latent heats of the microcapsules were measured as 35.2 C and 34.9 C, 84.2 and -87.5 J/g, respectively. TGA analysis indicated that PMMA/eicosane microcapsules degrade in three steps at considerably high temperatures. Accelerated thermal cycling tests have been also applied to show the thermal reliability of the microcapsules. All results showed that thermal properties make the PMMA/eicosane microcapsules potential PCM for thermal energy storage. (author)

  16. University of Minnesota Aquifer Thermal Energy Storage Field Test Facility

    Science.gov (United States)

    Walton, M.; Hoyer, M. C.

    1982-12-01

    The University of Minnesota Aquifer Thermal Energy Storage (ATES) Field Test Facility became operational. Experiments demonstrated that the Franconia-Ironton-Galesville aquifer will accept injection of 300 gpm (18.9 1 sec (-1)) at reasonable pressures with a heat buildup in the injection well of about 44 psi (31.6 m) over 8 days. Heating of the ground water caused precipitation of carbonate in the piping and injection well, but with proper water conditioning, the system will work satisfactorily at elevated temperatures.

  17. Literature review of market studies of thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Hattrup, M.P.

    1988-02-01

    This report presents the results of a review of market studies of thermal energy storage (TES). This project was conducted by Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE). PNL staff reviewed and consolidated the findings of existing TES market studies conducted in the industrial, commercial, and residential sectors. The purpose of this project was to review and assess previous work and to use the information obtained to help provide direction for future technology transfer planning activities and to identify additional economic research needed within those three sectors. 37 refs.

  18. Bibliography of the seasonal thermal energy storage library

    Energy Technology Data Exchange (ETDEWEB)

    Prater, L.S.; Casper, G.; Kawin, R.A.

    1981-08-01

    The Main Listing is arranged alphabetically by the last name of the first author. Each citation includes the author's name, title, publisher, publication date, and where applicable, the National Technical Information Service (NTIS) number or other document number. The number preceding each citation is the identification number for that document in the Seasonal Thermal Energy Storage (STES) Library. Occasionally, one or two alphabetic characters are added to the identification number. These alphabetic characters indicate that the document is contained in a collection of papers, such as the proceedings of a conference. An Author Index and an Identification Number Index are included. (WHK)

  19. Thermal energy storage systems using fluidized bed heat exchangers

    Science.gov (United States)

    Ramanathan, V.; Weast, T. E.; Ananth, K. P.

    1980-01-01

    The viability of using fluidized bed heat exchangers (FBHX) for thermal energy storage (TES) in applications with potential for waste heat recovery was investigated. Of the candidate applications screened, cement plant rotary kilns and steel plant electric arc furnaces were identified, via the chosen selection criteria, as having the best potential for successful use of FBHX/TES system. A computer model of the FBHX/TES systems was developed and the technical feasibility of the two selected applications was verified. Economic and tradeoff evaluations in progress for final optimization of the systems and selection of the most promising system for further concept validation are described.

  20. Thermal storage for industrial process and reject heat

    Science.gov (United States)

    Duscha, R. A.; Masica, W. J.

    1978-01-01

    Industrial production uses about 40% of the total energy consumed in the United States. The major share of this is derived from fossil fuel. Potential savings of scarce fuel is possible through the use of thermal energy storage (TES) of reject or process heat for subsequent use. Results of study contracts awarded by the Department of Energy (DOE) and managed by the NASA Lewis Research Center have identified three especially significant industries where high temperature TES appears attractive - paper and pulp, iron and steel, and cement. Potential annual fuel savings with large scale implementation of near-term TES systems for these three industries is nearly 9 million bbl of oil.

  1. Thermal energy storage for industrial waste heat recovery

    Science.gov (United States)

    Hoffman, H. W.; Kedl, R. J.; Duscha, R. A.

    1978-01-01

    The potential is examined for waste heat recovery and reuse through thermal energy storage in five specific industrial categories: (1) primary aluminum, (2) cement, (3) food processing, (4) paper and pulp, and (5) iron and steel. Preliminary results from Phase 1 feasibility studies suggest energy savings through fossil fuel displacement approaching 0.1 quad/yr in the 1985 period. Early implementation of recovery technologies with minimal development appears likely in the food processing and paper and pulp industries; development of the other three categories, though equally desirable, will probably require a greater investment in time and dollars.

  2. Customer attitudes toward thermal-energy-storage heating

    Science.gov (United States)

    Hersh, H. N.

    1981-06-01

    Attitudes among users of thermal energy storage (TES) heating systems were studied. A customer acceptance survey exploring attitudes and levels of satisfaction, face to face contacts between utility representatives and users, and a survey of pertinent published information are investigated. It is found that: (1) TES heating systems are installed for economic reasons by customers who can afford higher initial costs and understand the concept of lower total cost; and (2) attitudes toward TES are positive. The TES systems are not regarded more favorably than conventional systems, however, and it is likely that lower electric heating bills are responsible for the favorable perceptions of most TES users.

  3. The thermal environment and occupant perceptions in European office buildings

    Energy Technology Data Exchange (ETDEWEB)

    Stoops, J.L. [Chalmers Univ. of Tech., Goeteborg (Sweden). Dept. of Building Services Engineering

    2002-02-01

    The results from a large field study of thermal comfort in European office buildings are reported. Environmental conditions and occupant perceptions were collected over fourteen months from twenty-six different office buildings located in France, Greece, Portugal, Sweden and the UK. This thesis focuses on the thermal measurements and occupant perceptions; however, some of the additional variables with strong connections to thermal sensation are also examined. A summary of human comfort is presented to help place this thesis in appropriate context. The summary presents thermal comfort issues within a broad framework of environmental comfort including physical, physiological, behavioural, psychological and other variables. A more narrowly focused overview of current thermal comfort research is also included. The work attempts to show relationships and produce useful information from the data set by using rather simple statistics and graphical methods. The objective is to quite literally use the data set to illustrate the actual thermal conditions in European office buildings and the occupant perceptions of those conditions. The data are examined in some detail with key relationships identified and explored. Significant differences between countries, both for the physical conditions and the perceptions of those conditions are identified. In addition, the variation over the course of the year for each country is explored. The variations occur in complex ways, which make simple, all encompassing explanations impossible. The nature and size of the variations make the application of simple Europe wide models of thermal comfort questionable. It appears that individuals in different European countries have different expectations for their indoor office thermal environment. This data set will be further explored in a more complete study, which will examine the other measured variables.

  4. Study of thermal energy storage using fluidized bed heat exchangers

    Science.gov (United States)

    Weast, T. E.; Shannon, L. J.; Ananth, K. P.

    1980-01-01

    The technical and economic feasibility of fluid bed heat exchangers (FBHX) for thermal energy storage (TES) in waste heat recovery applications is assessed by analysis of two selected conceptual systems, the rotary cement kiln and the electric arc furnace. It is shown that the inclusion of TES in the energy recovery system requires that the difference in off-peak and on-peak energy rates be large enough so that the value of the recovered energy exceeds the value of the stored energy by a wide enough margin to offset parasitic power and thermal losses. Escalation of on-peak energy rates due to fuel shortages could make the FBHX/TES applications economically attractive in the future.

  5. Value of Concentrating Solar Power and Thermal Energy Storage

    Energy Technology Data Exchange (ETDEWEB)

    Sioshansi, R.; Denholm, P.

    2010-02-01

    This paper examines the value of concentrating solar power (CSP) and thermal energy storage (TES) in four regions in the southwestern United States. Our analysis shows that TES can increase the value of CSP by allowing more thermal energy from a CSP plant?s solar field to be used, by allowing a CSP plant to accommodate a larger solar field, and by allowing CSP generation to be shifted to hours with higher energy prices. We analyze the sensitivity of CSP value to a number of factors, including the optimization period, price and solar forecasting, ancillary service sales, capacity value and dry cooling of the CSP plant. We also discuss the value of CSP plants and TES net of capital costs.

  6. Thermal Comfort in a Naturally-Ventilated Educational Building

    Directory of Open Access Journals (Sweden)

    David Mwale Ogoli

    2012-11-01

    Full Text Available A comprehensive study of thermal comfort in a naturally ventilated education building (88,000 ft2 in a Chicago suburb will be conducted with 120 student subjects in 2007. This paper discusses some recent trends in worldwide thermal comfort studies and presents a proposal of research for this building through a series of questionnaire tables. Two research methods used inthermal comfort studies are field studies and laboratory experiments in climate-chambers. The various elements that constitute a “comfortable” thermal environment include physical factors (ambient air temperature, mean radiant temperature, air movement and humidity, personal factors(activity and clothing, classifications (gender, age, education, etc. and psychological expectations (knowledge, experience, psychological effect of visual warmth by, say, a fireplace. Comparisons are made using data gathered from Nairobi, Kenya.Keywords: Comfort, temperature, humidity and ventilation

  7. Thermal performance of PCM thermal storage unit for a roof integrated solar heating system

    Energy Technology Data Exchange (ETDEWEB)

    Saman, W.; Bruno, F.; Halawa, E. [South Australia Univ., Sustainable Energy Centre, Adelaide, SA (Australia)

    2005-02-01

    The thermal performance of a phase change thermal storage unit is analysed and discussed. The storage unit is a component of a roof integrated solar heating system being developed for space heating of a home. The unit consists of several layers of phase change material (PCM) slabs with a melting temperature of 29 deg C. Warm air delivered by a roof integrated collector is passed through the spaces between the PCM layers to charge the storage unit. The stored heat is utilised to heat ambient air before being admitted to a living space. The study is based on both experimental results and a theoretical two dimensional mathematical model of the PCM employed to analyse the transient thermal behaviour of the storage unit during the charge and discharge periods. The analysis takes into account the effects of sensible heat which exists when the initial temperature of the PCM is well below or above the melting point during melting or freezing. The significance of natural convection occurring inside the PCM on the heat transfer rate during melting which was previously suspected as the cause of faster melting process in one of the experiments is discussed. The results are compared with a previous analysis based on a one dimensional model which neglected the effect of sensible heat. A comparison with experimental results for a specific geometry is also made. (Author)

  8. Dish Stirling High Performance Thermal Storage FY14Q3 Quad Chart.

    Energy Technology Data Exchange (ETDEWEB)

    Andraka, Charles E. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2014-07-01

    The project goals are: demonstrate the feasibility of significant thermal storage for dish Stirling systems to leverage their existing high performance to greater capacity; demonstrate key components of a latent storage and transport system enabling on-dish storage with low exergy losses; an provide technology path to a 25kWe system with 6 hours of storage.

  9. The influence of thermal insulation position in building exterior walls on indoor thermal comfort and energy consumption of residential buildings in Chongqing

    Science.gov (United States)

    Wang, D.; Yu, W.; Zhao, X.; Dai, W.; Ruan, Y.

    2016-08-01

    This paper focused on the influence of using position of thermal insulation materials in exterior walls on the indoor thermal comfort and building energy consumption of residential building in Chongqing. In this study, four (4) typical residential building models in Chongqing were established, which have different usage of thermal insulation layer position in exterior walls. Indoor thermal comfort hours, cooling and heating energy consumption of each model were obtained by using a simulation tool, Energyplus. Based on the simulation data, the influence of thermal insulation position on indoor thermal comfort and building energy consumption in each season was analyzed. The results showed that building with internal insulation had the highest indoor thermal comfort hours and least cooling and heating energy consumption in summer and winter. In transitional season, the highest indoor thermal comfort hours are obtained when thermal insulation is located on the exterior side.

  10. Elaboration of Conductive Thermal Storage Composites Made of Phase Change Materials and Graphite for Solar Plant

    Energy Technology Data Exchange (ETDEWEB)

    Pincemin, S.; Py, X.; Olives, R.; Christ, M.; Oettinger, O.

    2006-07-01

    New thermal storage composites made of graphite and PCM have been developed for the Solar plant of Almeria TROUGH different elaboration routes. Those materials are presented with their respective properties (enhanced thermal conductivities, thermal storage capacities, stability) and compared together. Both the laboratory and industrial scales are considered and corresponding material compared. (Author)

  11. THERMAL ENERGY STORAGE PROPERTIES OF FORMSTABLE PARAFFIN/RECYCLE BLOCK CONCRETE COMPOSITE PHASE CHANGE MATERIAL

    Directory of Open Access Journals (Sweden)

    PATTARAPORN SUTTAPHAKDEE

    2017-01-01

    Full Text Available In this research, the form-stable composite phase change material was developed by incorporating paraffin on recycle block concrete (RB through the vacuum impregnation method. The compatibility and thermal properties of RB impregnated with paraffin ranging from 0-35 wt% were characterized by Fourier transform infrared spectroscopy (FTIR and differential scanning calorimetry (DSC. Results revealed that paraffin was uniformly absorbed in RB with a good physical compatibility. The optimum adsorption ratio of paraffin in RB was 25 wt% which produced phase transition temperature of 52.85 OC and latent heat of 30.98 J/g. The obtained form-stable paraffin/RB composite PCM had proper latent heat and phase transition temperature and can be applied for thermal energy storage applications such as solar heating and cooling in buildings.

  12. Thermal battery with CO2 compression heat pump: Techno-economic optimization of a high-efficiency Smart Grid option for buildings

    OpenAIRE

    Blarke, Morten B.; Yazawa, Kazuaki; Shakouri, Ali; Carmo, Carolina

    2012-01-01

    Increasing penetration levels of wind and solar power in the energy system call for the development of Smart Grid enabling technologies. As an alternative to expensive electro-chemical and mechanical storage options, the thermal energy demand in buildings offers a cost-effective option for intermittency-friendly electricity consumption patterns. Combining hot and cold thermal storages with new high-pressure compressor technology that allows for flexible and simultaneous production of useful h...

  13. Models for describing the thermal characteristics of building components

    DEFF Research Database (Denmark)

    Jimenez, M.J.; Madsen, Henrik

    2008-01-01

    Outdoor testing of buildings and building components under real weather conditions provides useful information about their dynamic performance. Such knowledge is needed to properly characterize the heat transfer dynamics and provides useful information for implementing energy saving strategies...... of these approaches may therefore be very useful for selecting a suitable approach for each particular case. This paper presents an overview of models that can be applied for modelling the thermal characteristics of buildings and building components using data from outdoor testing. The choice of approach depends......, for example. For the analysis of these tests, dynamic analysis models and methods are required. However, a wide variety of models and methods exists, and the problem of choosing the most appropriate approach for each particular case is a non-trivial and interdisciplinary task. Knowledge of a large family...

  14. Candidate thermal energy storage technologies for solar industrial process heat applications

    Science.gov (United States)

    Furman, E. R.

    1979-01-01

    A number of candidate thermal energy storage system elements were identified as having the potential for the successful application of solar industrial process heat. These elements which include storage media, containment and heat exchange are shown.

  15. Evaluation of the effects of vegetation and green walls on building thermal performance and energy consumption

    Science.gov (United States)

    Susorova, Irina

    This research explored the use of vegetation in building facades as a potential solution to the problems of urban ecology and the excessive energy consumption in buildings. Vegetated facades substantially reduce building energy use, reduce the urban heat island effect, improve air quality, and increase the biodiversity of plants and animals in cities. The goal of this research was to evaluate the effects of plants on building thermal performance and energy consumption by developing a thermal model of a building facade covered with a layer of plants. The developed mathematical model accounts for thermal physical processes in a vegetated exterior wall including solar radiation, infrared radiative exchange between the facade and sky, the facade and ground, the facade and vegetation layer, convection to and from the facade, evapotranspiration from the plant layer, heat storage in the facade material, and heat conduction through the facade. The model calculates vegetated facade surface temperature and heat flux through the facade for multiple weather conditions, plant physiological characteristics, and facade parameters inputs. The model was validated with the results of a one-week long experiment measuring the thermal properties of bare and vegetated facades on the Illinois Institute of Technology campus. The experiment and subsequent sensitivity analysis demonstrated that a plant layer can effectively reduce the facade exterior surface temperature, daily temperature fluctuations, exterior wall temperature gradient, and, as a result, provide as much additional thermal insulation to the facade as a 2.5 cm layer of expanded polystyrene insulation. The vegetated facade model was also used to analyze the reduction in energy consumption in generic office and residential thermal zones for multiple parameters. The simulations showed that energy reduction could be as high as 6.2% of annual total energy use and 34.6% of cooling energy use in residential thermal zones. Overall

  16. Thermally responsive polymer electrolytes for inherently safe electrochemical energy storage

    Science.gov (United States)

    Kelly, Jesse C.

    Electrochemical double layer capacitors (EDLCs), supercapacitors and Li-ion batteries have emerged as premier candidates to meet the rising demands in energy storage; however, such systems are limited by thermal hazards, thermal runaway, fires and explosions, all of which become increasingly more dangerous in large-format devices. To prevent such scenarios, thermally-responsive polymer electrolytes (RPEs) that alter properties in electrochemical energy storage devices were designed and tested. These RPEs will be used to limit or halt device operation when temperatures increase beyond a predetermined threshold, therefore limiting further heating. The development of these responsive systems will offer an inherent safety mechanism in electrochemical energy storage devices, while preserving the performance, lifetimes, and versatility that large-format systems require. Initial work focused on the development of a model system that demonstrated the concept of RPEs in an electrochemical device. Aqueous electrolyte solutions of polymers exhibiting properties that change in response to temperature were developed for applications in EDLCs and supercapacitors. These "smart materials" provide a means to control electrochemical systems where polymer phase separation at high temperatures affects electrolyte properties and inhibits device performance. Aqueous RPEs were synthesized using N-isopropylacrylamide, which governs the thermal properties, and fractions of acrylic acid or vinyl sulfonic acids, which provide ions to the solution. The molecular properties of these aqueous RPEs, specifically the ionic composition, were shown to influence the temperature-dependent electrolyte properties and the extent to which these electrolytes control the energy storage characteristics of a supercapacitor device. Materials with high ionic content provided the highest room temperature conductivity and electrochemical activity; however, RPEs with low ionic content provided the highest "on

  17. Ice Thermal Storage Systems for LWR Supplemental Cooling and Peak Power Shifting

    Energy Technology Data Exchange (ETDEWEB)

    Haihua Zhao; Hongbin Zhang; Phil Sharpe; Blaise Hamanaka; Wei Yan; WoonSeong Jeong

    2010-06-01

    Availability of enough cooling water has been one of the major issues for the nuclear power plant site selection. Cooling water issues have frequently disrupted the normal operation at some nuclear power plants during heat waves and long draught. The issues become more severe due to the new round of nuclear power expansion and global warming. During hot summer days, cooling water leaving a power plant may become too hot to threaten aquatic life so that environmental regulations may force the plant to reduce power output or even temporarily to be shutdown. For new nuclear power plants to be built at areas without enough cooling water, dry cooling can be used to remove waste heat directly into the atmosphere. However, dry cooling will result in much lower thermal efficiency when the weather is hot. One potential solution for the above mentioned issues is to use ice thermal storage systems (ITS) that reduce cooling water requirements and boost the plant’s thermal efficiency in hot hours. ITS uses cheap off-peak electricity to make ice and uses those ice for supplemental cooling during peak demand time. ITS is suitable for supplemental cooling storage due to its very high energy storage density. ITS also provides a way to shift large amount of electricity from off peak time to peak time. Some gas turbine plants already use ITS to increase thermal efficiency during peak hours in summer. ITSs have also been widely used for building cooling to save energy cost. Among three cooling methods for LWR applications: once-through, wet cooling tower, and dry cooling tower, once-through cooling plants near a large water body like an ocean or a large lake and wet cooling plants can maintain the designed turbine backpressure (or condensation temperature) during 99% of the time; therefore, adding ITS to those plants will not generate large benefits. For once-through cooling plants near a limited water body like a river or a small lake, adding ITS can bring significant economic

  18. Solar dryer with thermal storage and biomass-backup heater

    Energy Technology Data Exchange (ETDEWEB)

    Madhlopa, A. [Department of Physics and Biochemical Sciences, Malawi Polytechnic, P/Bag 303, Blantyre 3 (Malawi); Ngwalo, G. [Department of Mechanical Engineering, Malawi Polytechnic, P/Bag 303, Blantyre 3 (Malawi)

    2007-04-15

    An indirect type natural convection solar dryer with integrated collector-storage solar and biomass-backup heaters has been designed, constructed and evaluated. The major components of the dryer are biomass burner (with a rectangular duct and flue gas chimney), collector-storage thermal mass and drying chamber (with a conventional solar chimney). The thermal mass was placed in the top part of the biomass burner enclosure. The dryer was fabricated using simple materials, tools and skills, and it was tested in three modes of operation (solar, biomass and solar-biomass) by drying twelve batches of fresh pineapple (Ananas comosus), with each batch weighing about 20 kg. Meteorological conditions were monitored during the dehydration process. Moisture and vitamin C contents were determined in both fresh and dried samples. Results show that the thermal mass was capable of storing part of the absorbed solar energy and heat from the burner. It was possible to dry a batch of pineapples using solar energy only on clear days. Drying proceeded successfully even under unfavorable weather conditions in the solar-biomass mode of operation. In this operational mode, the dryer reduced the moisture content of pineapple slices from about 669 to 11% (db) and yielded a nutritious dried product. The average values of the final-day moisture-pickup efficiency were 15%, 11% and 13% in the solar, biomass and solar-biomass modes of operation respectively. It appears that the solar dryer is suitable for preservation of pineapples and other fresh foods. Further improvements to the system design are suggested. (author)

  19. Detailed partial load investigation of a thermal energy storage concept for solar thermal power plants with direct steam generation

    Science.gov (United States)

    Seitz, M.; Hübner, S.; Johnson, M.

    2016-05-01

    Direct steam generation enables the implementation of a higher steam temperature for parabolic trough concentrated solar power plants. This leads to much better cycle efficiencies and lower electricity generating costs. For a flexible and more economic operation of such a power plant, it is necessary to develop thermal energy storage systems for the extension of the production time of the power plant. In the case of steam as the heat transfer fluid, it is important to use a storage material that uses latent heat for the storage process. This leads to a minimum of exergy losses during the storage process. In the case of a concentrating solar power plant, superheated steam is needed during the discharging process. This steam cannot be superheated by the latent heat storage system. Therefore, a sensible molten salt storage system is used for this task. In contrast to the state-of-the-art thermal energy storages within the concentrating solar power area of application, a storage system for a direct steam generation plant consists of a latent and a sensible storage part. Thus far, no partial load behaviors of sensible and latent heat storage systems have been analyzed in detail. In this work, an optimized fin structure was developed in order to minimize the costs of the latent heat storage. A complete system simulation of the power plant process, including the solar field, power block and sensible and latent heat energy storage calculates the interaction between the solar field, the power block and the thermal energy storage system.

  20. Design Novel 3D Nano Architectures for Developing Ultra Fast Thermal Energy Storage Materials

    Science.gov (United States)

    2015-04-30

    AFRL-AFOSR-UK-TR-2015-0036 Design novel 3D nano-architectures for developing ultra fast thermal energy storage materials...ultra fast thermal energy storage materials 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA8655-12-1-2014 5c. PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S...ANSI Std. Z39.18 FINAL TECHNICAL REPORT Project Title : Design novel 3D nano-architectures for developing ultra fast thermal energy storage

  1. Features of Functioning the Integrated Building Thermal Model

    Directory of Open Access Journals (Sweden)

    Morozov Maxim N.

    2017-01-01

    Full Text Available A model of the building heating system, consisting of energy source, a distributed automatic control system, elements of individual heating unit and heating system is designed. Application Simulink of mathematical package Matlab is selected as a platform for the model. There are the specialized application Simscape libraries in aggregate with a wide range of Matlab mathematical tools allow to apply the “acausal” modeling concept. Implementation the “physical” representation of the object model gave improving the accuracy of the models. Principle of operation and features of the functioning of the thermal model is described. The investigations of building cooling dynamics were carried out.

  2. On a computational model of building thermal dynamic response

    Science.gov (United States)

    Jarošová, Petra; Vala, Jiří

    2016-07-01

    Development and exploitation of advanced materials, structures and technologies in civil engineering, both for buildings with carefully controlled interior temperature and for common residential houses, together with new European and national directives and technical standards, stimulate the development of rather complex and robust, but sufficiently simple and inexpensive computational tools, supporting their design and optimization of energy consumption. This paper demonstrates the possibility of consideration of such seemingly contradictory requirements, using the simplified non-stationary thermal model of a building, motivated by the analogy with the analysis of electric circuits; certain semi-analytical forms of solutions come from the method of lines.

  3. Thermal Analysis of a Solar Powered Absorption Cooling System with Fully Mixed Thermal Storage at Startup

    Directory of Open Access Journals (Sweden)

    Camelia Stanciu

    2017-01-01

    Full Text Available A simple effect one stage ammonia-water absorption cooling system fueled by solar energy is analyzed. The considered system is composed by a parabolic trough collector concentrating solar energy into a tubular receiver for heating water. This is stored in a fully mixed thermal storage tank and used in the vapor generator of the absorption cooling system. Time dependent cooling load is considered for the air conditioning of a residential two-storey house. A parametric study is performed to analyze the operation stability of the cooling system with respect to solar collector and storage tank dimensions. The results emphasized that there is a specific storage tank dimension associated to a specific solar collector dimension that could ensure the longest continuous startup operation of the cooling system when constant mass flow rates inside the system are assumed.

  4. Field test of a thermal active building system (tabs) in an office building in Denmark

    DEFF Research Database (Denmark)

    Raimondo, Daniela; Olesen, Bjarne W.; Corgnati, Stefano P.

    2013-01-01

    An increasing attention has been addressed in the last years to the assessment, at the same time, of energy performances and indoor environmental quality in buildings. Focusing on thermal comfort recent international standards as ISOEN7730 and EN15251 introduce criteria for using categories...

  5. Adaptive thermal comfort for buildings in Portugal based on occupants' thermal perception

    Energy Technology Data Exchange (ETDEWEB)

    Matias, L.; Pina Santos, C.; Rebelo, M. [LNEC National Laboratory for Civil Engineering, Lisbon (Portugal); Almeida, S. [FCT Foundation for Science and Technology, Lisbon (Portugal); Correia Guedes, M. [IST Higher Technical Inst., Lisbon (Portugal)

    2009-07-01

    The use of air conditioning systems in Portugal has increased in recent years. Most new service buildings are equipped with mechanical air conditioning systems, either due to commercial reasons, productivity, or due to high internal thermal loads, and solar gains through windows. However, a large percentage of older service buildings are still naturally ventilated. In ASHRAE 55 thermal comfort standard, an adaptive model was adopted as an optional method for determining acceptable thermal conditions in naturally conditioned spaces. Recently, Portugal's National Laboratory for Civil Engineering (LNEC) initiated an interdisciplinary research study in this field. The research team of physicists, social scientists, and civil engineers developed better modeling of adaptive thermal strategies. This paper described the adaptive approach that defined indoor thermal comfort requirements applicable to Portuguese buildings. The study focused on assessing, in real use conditions, indoor environments and the response of occupants of office and educational buildings, and homes for the elderly. The results were obtained from 285 field surveys carried out on 40 buildings and a set of 2367 questionnaires completed by occupants. Field surveys assessed and measured the main indoor environmental parameters during summer, winter and mid-season. This paper included the results of the analysis to the occupants' thermal perception and expectation, by relating them to both measured and collected indoor thermal environments and outdoor climate. The relation between the occupants' thermal sensation and preference was analysed for different types of activities, throughout different seasons. Results showed that occupants may tolerate broader temperature ranges than those indicated in current standards, particularly in the heating season. 10 refs., 3 tabs., 9 figs.

  6. Hygrothermal evaluation of a museum storage building based on actual measurements and simulations

    DEFF Research Database (Denmark)

    Christensen, Jørgen Erik; Kollias, Christos Georgios

    2015-01-01

    environment facilities of a passive museum storage building in Vejle region in Denmark, are investigated. Results demonstrate that the weather conditions of the previous yearś considerably affect the indoor environment of the storage. What is more, concentrated dehumidification is a sufficient technique...

  7. Thermal storage and nonlinear heat-transfer characteristics of PCM wallboard

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yinping; Lin, Kunping; Jiang, Yi; Zhou, Guobing [Department of Building Science, Tsinghua University, Beijing 100084 (China)

    2008-07-01

    For the materials with constant thermophysical properties, the thermal performance of wallboards (or floor, ceiling) can be described by decrement factor f and time lag {phi}. However, the phase change material (PCM) may charge large heat during the melting process and discharge large heat during the freezing process, which takes place at some certain temperature or a narrow temperature range. The behavior deviates a lot from the material with constant thermal physical properties. Therefore, it is not reasonable to analyze the thermal performance of PCM wallboard by using the decrement factor f and time lag {phi}. How to simply and effectively analyze the thermal performance of a PCM wallboard is an important problem. In order to analyze and evaluate the energy-efficient effects of the PCM wallboard and floor, two new parameters, i.e., modifying factor of the inner surface heat flux '{alpha}' and ratio of the thermal storage 'b', are put forward. They can describe the thermal performance of PCM external and internal walls, respectively. The analysis and simulation methods are both applied to investigate the effects of different PCM thermophysical properties (heat of fusion H{sub m}, melting temperature T{sub m} and thermal conductivity k) on the thermal performance of PCM wallboard for the residential buildings. The results show that the PCM external wall can save more energy by increasing H{sub m}, decreasing k and selecting proper T{sub m} ({alpha}<1); that the PCM internal wall can save more energy by increasing H{sub m} and selecting appropriate T{sub m}, k. The most energy-efficient approach of applying PCM in a solar house is to apply it in its internal wall. (author)

  8. Dynamic simulation of residential buildings with seasonal sorption storage of solar energy - parametric analysis

    OpenAIRE

    Hennaut, Samuel; Thomas, Sébastien; Davin, Elisabeth; Andre, Philippe

    2011-01-01

    This work focuses on the evaluation of the performances of a solar combisystem coupled to seasonal thermochemical storage using SrBr2/H20 as adsorbent/adsorbate couple. The objective is to determine the characteristics required for solar system and storage reactor to reach a 100 % solar fraction for a building with a low heating load. The complete system, including the storage reactor, is simulated, using the dynamic simulation software TRNSYS. The influence of some components and p...

  9. Assessment Framework of Building Facade in Optimizing Indoor Thermal Comfort of Green Building Index (GBI Certified Office Building

    Directory of Open Access Journals (Sweden)

    Abdul Tharim Asniza Hamimi

    2016-01-01

    Full Text Available During the past decade, the construction industry has seen a new trend in the development of “green” or “sustainable” construction concept around the world with vast support from prominent organization, together with the introduction of sustainable building codes. The establishment of green building certification systems worldwide is seen as one of the most efforts in the emerging green building movement. In order to support the development of the “green” and “sustainable” concept in Malaysia, Green Building Index (GBI was launched by the government on 21 May 2009 that created to promote sustainability in the built environment and raise awareness of environmental issues. However, the construction industry seems to have focused only on findings the “right mechanism” for an environmentally sustainable “final result” in order for the building to be certified as green with the lacking of continuous assessment on the building performance after the certifications. This study is purposely conducted to investigate the performance of various rated Green Building Index (GBI Non-Residential New Construction office buildings and the influence on Indoor Thermal Comfort (ITC of the selected buildings. The aim is to develop an assessment framework for optimum green building architectural façade to be used for office buildings in Malaysia as well as to analyse the occupants’ perception, satisfaction and performance in the selected Green Building Index (GBI rated office indoor environment. This research is still in its infancy; therefore the paper is focused on research aims, research scope and methodology, and expected deliverables for the proposed research.

  10. Experimental study of influence of inlet geometry on thermal stratification in thermal energy storage during charging process

    Directory of Open Access Journals (Sweden)

    Švarc Petr

    2014-03-01

    Full Text Available Various analyses of charging processes of real single-medium thermal energy storage were applied in this work. Two different inlet geometries of direct intakes into thermal energy storage were investigated for the process of charging in Richardson numbers 0.4 and 15. Temperature distributions for both cases are shown and compared in selected time steps. Several simple methods for assessment of an ability to maintain and support thermal stratification during charging processes were compared with exergy analysis.

  11. Coupling of Thermal Mass with Night Ventilation in Buildings

    Science.gov (United States)

    Endurthy, Akhilesh Reddy

    Passive cooling designs & technologies offer great promise to lower energy use in buildings. Though the working principles of these designs and technologies are well understood, simplified tools to quantitatively evaluate their performance are lacking. Cooling by night ventilation, which is the topic of this research, is one of the well known passive cooling technologies. The building's thermal mass can be cooled at night by ventilating the inside of the space with the relatively lower outdoor air temperatures, thereby maintaining lower indoor temperatures during the warmer daytime period. Numerous studies, both experimental and theoretical, have been performed and have shown the effectiveness of the method to significantly reduce air conditioning loads or improve comfort levels in those climates where the night time ambient air temperature drops below that of the indoor air. The impact of widespread adoption of night ventilation cooling can be substantial, given the large fraction of energy consumed by air conditioning of buildings (about 12-13% of the total electricity use in U.S. buildings). Night ventilation is relatively easy to implement with minimal design changes to existing buildings. Contemporary mathematical models to evaluate the performance of night ventilation are embedded in detailed whole building simulation tools which require a certain amount of expertise and is a time consuming approach.

  12. Thermal Bridges in Building Construction - Measurements and Calculations

    DEFF Research Database (Denmark)

    Rose, Jørgen

    in building envelope constructions is given. After this a validation of both programs and guidelines is presented. The validation is performed by comparing calculated U-values with Guarded Hot Box measurements. The last part of the thesis discusses the possibilities of utilising the results of detailed...... calculations in more operational and applicable projecting tools, e.g. thermal bridge catalogues or U-value tables....

  13. Assessment of thermal insulation materials and systems for building applications

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-06-01

    The primary goal of the study was to provide a proper foundation for decision making by the federal government, industry, and consumer. The report may be used to identify areas where new test methods and standards are needed to establish new programs for improving thermal performance of buildings, and as a basis for setting new or improved standards after the recommended test programs have been completed.

  14. Thermal control system and method for a passive solar storage wall

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, J.K.E.

    1981-07-10

    A system and method are provided for controlling the storing and release of thermal energy from a thermal storage wall wherein said wall is capable of storing thermal energy from insolation. The system and method includes a device such as a plurality of louvers spaced a predetermined distance from the thermal wall for regulating the release of thermal energy from the thermal wall. This regulating device is made from a material which is substantially transparent to the incoming solar radiation so that when it is in any operative position, the thermal storage wall substantially receives all of the impacting solar radiation. The material in the regulating device is further capable of being substantially opaque to thermal energy so that when the device is substantially closed, thermal release of energy from the storage wall is substantially minimized. An adjustment device is interconnected with the regulating mechanism for selectively opening and closing it in order to regulate the release of thermal energy from the wall.

  15. The roles of thermal insulation and heat storage in the energy performance of the wall materials: a simulation study.

    Science.gov (United States)

    Long, Linshuang; Ye, Hong

    2016-04-07

    A high-performance envelope is the prerequisite and foundation to a zero energy building. The thermal conductivity and volumetric heat capacity of a wall are two thermophysical properties that strongly influence the energy performance. Although many case studies have been performed, the results failed to give a big picture of the roles of these properties in the energy performance of an active building. In this work, a traversal study on the energy performance of a standard room with all potential wall materials was performed for the first time. It was revealed that both heat storage materials and insulation materials are suitable for external walls. However, the importances of those materials are distinct in different situations: the heat storage plays a primary role when the thermal conductivity of the material is relatively high, but the effect of the thermal insulation is dominant when the conductivity is relatively low. Regarding internal walls, they are less significant to the energy performance than the external ones, and they need exclusively the heat storage materials with a high thermal conductivity. These requirements for materials are consistent under various climate conditions. This study may provide a roadmap for the material scientists interested in developing high-performance wall materials.

  16. High-rise Buildings versus Outdoor Thermal Environment in Chongqing

    Directory of Open Access Journals (Sweden)

    Jin-sha Wang

    2007-10-01

    Full Text Available This paper gives a brief description of the over quick urbanization sinceChongqing, one of the biggest cities in China, has been a municipality directly under theCentral Government in 1997, excessive development and exceeding increase of high-risebuildings because of its special geographical position which finally leads to the worseningof the urban outdoor thermal environment. Then, this paper makes a bright balance to thefield measurement and simulated results of the wind speed field, temperature field of onemultifunctional high-rise building in Chongqing university located in the city center, andthe contrasted results validate the correctness of CFD in the outdoor thermal environmentalsimulation, expose the disadvantages of high-rise buildings on the aspects of blocking thewind field, decreasing wind speed which results in accumulation of the air-conditioningheat revolving around and periscian region where sunshine can not rip into. Finally, inorder to improve the urban outdoor thermal environment near the high-rise buildingsespecially for the angle of natural ventilation, this paper simulates the wind environment indifferent architectural compositions and architectural layouts by CFD, and the simulatedresults show that freestyle and tower buildings which can guarantee the wind speed andtake the air-conditioning heat away are much suitable and reasonable for the specialChongqing geography. These conclusions can also be used as a reference in othermountain cities, especially for the one with a great number of populations.

  17. Advanced Thermal Storage for Central Receivers with Supercritical Coolants

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Bruce D.

    2010-06-15

    The principal objective of the study is to determine if supercritical heat transport fluids in a central receiver power plant, in combination with ceramic thermocline storage systems, offer a reduction in levelized energy cost over a baseline nitrate salt concept. The baseline concept uses a nitrate salt receiver, two-tank (hot and cold) nitrate salt thermal storage, and a subcritical Rankine cycle. A total of 6 plant designs were analyzed, as follows: Plant Designation Receiver Fluid Thermal Storage Rankine Cycle Subcritical nitrate salt Nitrate salt Two tank nitrate salt Subcritical Supercritical nitrate salt Nitrate salt Two tank nitrate salt Supercritical Low temperature H2O Supercritical H2O Two tank nitrate salt Supercritical High temperature H2O Supercritical H2O Packed bed thermocline Supercritical Low temperature CO2 Supercritical CO2 Two tank nitrate salt Supercritical High temperature CO2 Supercritical CO2 Packed bed thermocline Supercritical Several conclusions have been drawn from the results of the study, as follows: 1) The use of supercritical H2O as the heat transport fluid in a packed bed thermocline is likely not a practical approach. The specific heat of the fluid is a strong function of the temperatures at values near 400 °C, and the temperature profile in the bed during a charging cycle is markedly different than the profile during a discharging cycle. 2) The use of supercritical CO2 as the heat transport fluid in a packed bed thermocline is judged to be technically feasible. Nonetheless, the high operating pressures for the supercritical fluid require the use of pressure vessels to contain the storage inventory. The unit cost of the two-tank nitrate salt system is approximately $24/kWht, while the unit cost of the high pressure thermocline system is nominally 10 times as high. 3) For the supercritical fluids, the outer crown temperatures of the receiver tubes are in the range of 700 to 800 °C. At temperatures of 700 °C and above

  18. Airways in Apartment Buildings as a Method of Thermal Control

    Directory of Open Access Journals (Sweden)

    Suslova Anna

    2016-01-01

    Full Text Available In general, the majority of modern apartment buildings are rather high. Altitude of such structures attains 50 meters. It is clear that for such high structures every extra meter of elevation costs a lot. For this reason, architects are trying to avoid adding attics above the last floor of the buildings. However, attic is not only an architectural element. It is an important part of the thermal control process of the entire building, especially of the apartments located on the last floor. In this article, construction of airways under the roof is suggested and discussed in detail. Airway acts as an attic, but has a significantly lower construction cost due to the lower height. Application of this technology allows providing comfortable microclimate on the living quarters in an economical way.

  19. Thermal Energy Optimization of Building Integrated Semi-Transparent Photovoltaic Thermal Systems

    OpenAIRE

    Ekoe A Akata Aloys Martial; Donatien Njomo; Basant Agrawal

    2015-01-01

    Building integrated photovoltaic (BIPV) : The concept where the photovoltaic element assumes the function of power generation and the role of the covering component element has the potential to become one of the principal sources of renewable energy for domestic purpose. In this paper, a Building integrated semitransparent photovoltaic thermal system (BISPVT) system having fins at the back sheet of the photovoltaic module has been simulated. It has been observed that this system produces high...

  20. Flight experiment of thermal energy storage. [for spacecraft power systems

    Science.gov (United States)

    Namkoong, David

    1989-01-01

    Thermal energy storage (TES) enables a solar dynamic system to deliver constant electric power through periods of sun and shade. Brayton and Stirling power systems under current considerations for missions in the near future require working fluid temperatures in the 1100 to 1300+ K range. TES materials that meet these requirements fall into the fluoride family of salts. Salts shrink as they solidify, a change reaching 30 percent for some salts. Hot spots can develop in the TES container or the container can become distorted if the melting salt cannot expand elsewhere. Analysis of the transient, two-phase phenomenon is being incorporated into a three-dimensional computer code. The objective of the flight program is to verify the predictions of the code, particularly of the void location and its effect on containment temperature. The four experimental packages comprising the program will be the first tests of melting and freezing conducted under microgravity.

  1. A convolution model of rock bed thermal storage units

    Science.gov (United States)

    Sowell, E. F.; Curry, R. L.

    1980-01-01

    A method is presented whereby a packed-bed thermal storage unit is dynamically modeled for bi-directional flow and arbitrary input flow stream temperature variations. The method is based on the principle of calculating the output temperature as the sum of earlier input temperatures, each multiplied by a predetermined 'response factor', i.e., discrete convolution. A computer implementation of the scheme, in the form of a subroutine for a widely used solar simulation program (TRNSYS) is described and numerical results compared with other models. Also, a method for efficient computation of the required response factors is described; this solution is for a triangular input pulse, previously unreported, although the solution method is also applicable for other input functions. This solution requires a single integration of a known function which is easily carried out numerically to the required precision.

  2. Thermal properties of a new ecological building material / Granular cork embedded in white cement

    Directory of Open Access Journals (Sweden)

    Cherki Abou-bakr

    2014-04-01

    Full Text Available Cork, natural and renewable product, has thermal and acoustic properties very interesting because of its microstructure and porosity representing a significant portion of its apparent volume; it’s coming from Moroccan Maamora’s forest. This work is a contribution to understand the thermal behaviour of the composite material based on granular cork embedded in white cement. An experimental investigation of its thermal properties was mainly performed using the asymmetrical device of transient Hot Plate method. The effect of granular cork size on the thermal properties of the mixture was studied. The experimental study of this sustainable material aims to characterize its thermal properties and then compare them with those of white cement without cork for motivate the proposal that this composite material will be used as walls insulator. A comparison of the energy performances of the composite material and white cement was made; it allows deducing a very interesting energy gain. The findings of the experiments indicate that the composite is better than white cement in term of thermal insulation, energy storage capacity and lightness. So, it can be used to realize the internal walls insulation. Its utilization should contribute to the improvement of the energy efficiency in building especially that this is a mixture based on a sustainable and renewable material.

  3. Rocks, Clays, Water, and Salts: Highly Durable, Infinitely Rechargeable, Eminently Controllable Thermal Batteries for Buildings

    Directory of Open Access Journals (Sweden)

    Alan W. Rempel

    2013-01-01

    Full Text Available Materials that store the energy of warm days, to return that heat during cool nights, have been fundamental to vernacular building since ancient times. Although building with thermally rechargeable materials became a niche pursuit with the advent of fossil fuel-based heating and cooling, energy and climate change concerns have sparked new enthusiasm for these substances of high heat capacity and moderate thermal conductivity: stone, adobe, rammed earth, brick, water, concrete, and more recently, phase-change materials. While broadly similar, these substances absorb and release heat in unique patterns characteristic of their mineralogies, densities, fluidities, emissivities, and latent heats of fusion. Current architectural practice, however, shows little awareness of these differences and the resulting potential to match materials to desired thermal performance. This investigation explores that potential, illustrating the correspondence between physical parameters and thermal storage-and-release patterns in direct-, indirect-, and isolated-gain passive solar configurations. Focusing on heating applications, results demonstrate the superiority of water walls for daytime warmth, the tunability of granite and concrete for evening warmth, and the exceptional ability of phase-change materials to sustain near-constant heat delivery throughout the night.

  4. Technical and economic feasibility of thermal energy storage. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Glenn, D.R.

    1976-02-01

    This study provides a first-look at the system elements involved in: (1) creating a market; (2) understanding and deriving the requirements; (3) performing analytical effort; (4) specifying equipment; and (5) synthesizing applications for a thermal energy storage (TES) function. The work reviews implicated markets, energy consumption patterns, TES technologies, and applications. Further, several concepts are developed and evaluated in some detail. Key findings are: (1) there are numerous technical opportunities for TES in the residential and industrial market sectors; (2) apart from sensible heat storage and transfer, significant R and D is required to fully exploit the superior heat densities of latent heat-based TES systems, particularly at temperatures above 600/sup 0/F; (3) industrial energy conservation can be favorably impacted by TES where periodic or batch-operated unit functions characterize product manufacturing processes, i.e. bricks, steel, and ceramics; and (4) a severe data shortage exists for describing energy consumption rates in real time as related to plant process operations--a needed element in designing TES systems.

  5. Influence of PCMs in thermal insulation on thermal behaviour of building envelopes

    Science.gov (United States)

    Dydek, K.; Furmański, P.; Łapka, P.

    2016-09-01

    A model of heat transfer through a wall consisting of a layer of concrete and PCM enhanced thermal insulation is considered. The model accounts for heat conduction in both layers, thermal radiation and heat absorption/release due to phase change in the insulation as well as time variation in the ambient temperature and insolation. Local thermal equilibrium between encapsulated PCM and light-weight thermal insulation was assumed. Radiation emission, absorption and scattering were also accounted for in the model. Comparison of different cases of heat flow through the building envelope was carried out. These cases included presence or absence of PCM and thermal radiation in the insulation, effect of emissivity of the PCM microcapsules as well as an effect of solar radiation or its lack on the ambient side of the envelope. Two ways of the PCM distribution in thermal insulation were also considered. The results of simulations were presented for conditions corresponding to the mean summer and winter seasons in Warsaw. It was found that thermal radiation plays an important role in heat transfer through thermal insulation layer of the wall while the presence of the PCM in it significantly contributes to damping of temperature fluctuations and a decrease in heat fluxes flowing into or lost by the interior of the building. The similar effect was observed for a decrease in emissivity of the microcapsules containing PCM.

  6. Energy Optimization for Transcritical CO2 Heat Pump for Combined Heating and Cooling and Thermal Storage Applications

    DEFF Research Database (Denmark)

    Do Carmo, Carolina Madeira Ramos; Blarke, Morten; Yazawa, Kazuaki

    2012-01-01

    A transcritical heat pump (THP) cycle using carbon dioxide (CO2) as the refrigerant is known to feature an excellent coefficient of performance (COP) as a thermodynamic system. Using this feature, we are designing and building a system that combines a water-to-water CO2 heat pump with both hot...... and cold thermal storages know as Thermal Battery (TB) (Blarke, 2012). Smart and effective use of intermittent renewable energy resources (for example solar and wind power) is obtained supplying water heating (>70 oC) and cooling services (

  7. Energy storage

    CERN Document Server

    Brunet, Yves

    2013-01-01

    Energy storage examines different applications such as electric power generation, transmission and distribution systems, pulsed systems, transportation, buildings and mobile applications. For each of these applications, proper energy storage technologies are foreseen, with their advantages, disadvantages and limits. As electricity cannot be stored cheaply in large quantities, energy has to be stored in another form (chemical, thermal, electromagnetic, mechanical) and then converted back into electric power and/or energy using conversion systems. Most of the storage technologies are examined: b

  8. Removal plan for Shippingport pressurized water reactor core 2 blanket fuel assemblies form T plant to the canister storage building

    Energy Technology Data Exchange (ETDEWEB)

    Lata

    1996-09-26

    This document presents the current strategy and path forward for removal of the Shippingport Pressurized Water Reactor Core 2 blanket fuel assemblies from their existing storage configuration (wet storage within the T Plant canyon) and transport to the Canister Storage Building (designed and managed by the Spent Nuclear Fuel. Division). The removal plan identifies all processes, equipment, facility interfaces, and documentation (safety, permitting, procedures, etc.) required to facilitate the PWR Core 2 assembly removal (from T Plant), transport (to the Canister storage Building), and storage to the Canister Storage Building. The plan also provides schedules, associated milestones, and cost estimates for all handling activities.

  9. Impacts of convection on high-temperature aquifer thermal energy storage

    Science.gov (United States)

    Beyer, Christof; Hintze, Meike; Bauer, Sebastian

    2016-04-01

    Seasonal subsurface heat storage is increasingly used in order to overcome the temporal disparities between heat production from renewable sources like solar thermal installations or from industrial surplus heat and the heat demand for building climatisation or hot water supply. In this context, high-temperature aquifer thermal energy storage (ATES) is a technology to efficiently store and retrieve large amounts of heat using groundwater wells in an aquifer to inject or withdraw hot or cold water. Depending on the local hydrogeology and temperature amplitudes during high-temperature ATES, density differences between the injected hot water and the ambient groundwater may induce significant convective flow components in the groundwater flow field. As a consequence, stored heat may accumulate at the top of the storage aquifer which reduces the heat recovery efficiency of the ATES system. Also, an accumulation of heat at the aquifer top will induce increased emissions of heat to overlying formations with potential impacts on groundwater quality outside of the storage. This work investigates the impacts of convective heat transport on the storage efficiency of a hypothetical high-temperature ATES system for seasonal heat storage as well as heat emissions to neighboring formations by numerical scenario simulations. The coupled groundwater flow and heat transport code OpenGeoSys is used to simulate a medium scale ATES system operating in a sandy aquifer of 20 m thickness with an average groundwater temperature of 10°C and confining aquicludes at top and bottom. Seasonal heat storage by a well doublet (i.e. one fully screened "hot" and "cold" well, respectively) is simulated over a period of 10 years with biannual injection / withdrawal cycles at pumping rates of 15 m³/h and for different scenarios of the temperature of the injected water (20, 35, 60 and 90 °C). Simulation results show, that for the simulated system significant convective heat transport sets in when

  10. Performance of thermal distribution systems in large commercial buildings

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Tengfang [Lawrence Berkeley National Lab. (LBNL), Univ. of California, Berkeley, CA (United States); Carrie, Remi F. [Lawrence Berkeley National Lab. (LBNL), Univ. of California, Berkeley, CA (United States); Dickerhoff, Darryl J. [Lawrence Berkeley National Lab. (LBNL), Univ. of California, Berkeley, CA (United States); Fisk, William J. [Lawrence Berkeley National Lab. (LBNL), Univ. of California, Berkeley, CA (United States); McWilliams, Jennifer [Lawrence Berkeley National Lab. (LBNL), Univ. of California, Berkeley, CA (United States); Wang, Duo [Lawrence Berkeley National Lab. (LBNL), Univ. of California, Berkeley, CA (United States); Modera, Mark P. [Lawrence Berkeley National Lab. (LBNL), Univ. of California, Berkeley, CA (United States)

    2001-12-08

    This paper presents major findings of a field study on the performance of five thermal distribution systems in four large commercial buildings. The five systems studied are typical single-duct or dual-duct constant air volume (CAV) systems and variable air volume (VAV) systems, each of which serves an office building or a retail building with floor area over 2000 m2. The air leakage from ducts is reported in terms of effective leakage area (ELA) at 25 Pa reference pressure, the ASHRAE-defined duct leakage class CL, and air leakage ratios. The specific ELAs ranged from 0.7 to 12.9 cm2/m2 of duct surface area, and from 0.1 to 7.7 cm2/m2 of floor area served. The ASHRAE-defined duct leakage classes ranged from 34 to 606 for the five systems and systems sections tested. The air leakage ratios were estimated to be up to approximately one-third of the fan-supplied airflow in the constant air volume systems. The specific ELAs and leakage classes indicated that air leakage in large commercial duct systems varied significantly from system to system, and from system section to system section even within the same thermal distribution system. Overall, the duct systems measured were much leakier than the ductwork specified as “unsealed ducts” by ASHRAE. On the other hand, thermal losses from supply ducts induced by conduction (including convection and radiation) were significant, on the scale that was comparable to the losses induced by air leakage in the duct systems. Furthermore, the energy losses induced by leakage and conduction suggested that there exist significant energy savings potentials from duct sealing and duct insulation practice in large commercial buildings.

  11. An analytical study of heat exchanger effectiveness and thermal performance in a solar energy storage system with PCM

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.C.Y.; Kwok, C.C.K.; Lin, S.; Vatistas, G.H.

    1984-05-01

    Solar thermal energy storage systems can be categorized based on materials that store either as sensible heat or as latent heat of fusion. For convenience, the latter are designated as phase change materials (PCM). It is a fairly well accepted fact that PCM storage devices usually require less storage volume. In a recent paper, heat exchanger effectiveness for PCM storage units was theoretically derived and presented in chart form. The heat exchanger considered was a shell-and-tube type, viz., the shell side filled with PCM and the tube side with heating or cooling fluid. The PCM heat storage system presented here, however, involves both heating and cooling fluids with a PCM in the middle composed of rectangular channels. This system may be used to store the thermal energy absorbed by a solar collector for the purpose of heating a building. The thermal energy carried by a hot fluid coming from the solar collector can be transferred through the upper surface I. The thermal energy stored in the system can be extracted through the lower surface II by a cold fluid circulating through the building. In order to transfer heat to the melting PCM, the temperature of the hot fluid must be higher than the melting point of the PCM, T /SUB m/ , and to remove heat from the solidifying PCM, the temperature of the cold fluid must be lower than T /SUB m/ . Therefore, the melting point of the PCM presents a limitation of the temperature of both the hot and cold fluids. This temperature limitation is more or less similar to the temperature restriction of a parallel-flow heat exchanger, in which the final temperature of the cold fluid can never reach the outlet temperature of the hot fluid.

  12. Technical and economic feasibility of thermal energy storage. Thermal energy storage application to the brick/ceramic industry. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Glenn, D.R.

    1976-10-01

    An initial project to study the technical and economic feasibility of thermal energy storage (TES) in the three major consumer markets, namely, the residential, commercial and industrial sectors is described. A major objective of the study was to identify viable TES applications from which a more concise study could be launched, leading to a conceptual design and in-depth validation of the TES energy impacts. This report documents one such program. The brick/ceramic industries commonly use periodic kilns which by their operating cycle require time-variant energy supply and consequently variable heat rejection. This application was one of the numerous TES opportunities that emerged from the first study, now available from the ERDA Technical Information Center, Oak Ridge, Tennessee, identified as Report No. COO-2558-1.

  13. Development of Hollow Steel Ball Macro-Encapsulated PCM for Thermal Energy Storage Concrete

    Directory of Open Access Journals (Sweden)

    Zhijun Dong

    2016-01-01

    Full Text Available The application of thermal energy storage with phase change materials (PCMs for energy efficiency of buildings grew rapidly in the last few years. In this research, octadecane paraffin was served as a PCM, and a structural concrete with the function of indoor temperature control was developed by using a macro-encapsulated PCM hollow steel ball (HSB. The macro-encapsulated PCM-HSB was prepared by incorporation of octadecane into HSBs through vacuum impregnation. Test results showed that the maximum percentage of octadecane carried by HSBs was 80.3% by mass. The macro-encapsulated PCM-HSB has a latent heat storage capacity as high as 200.5 J/g. The compressive strength of concrete with macro-encapsulated PCM-HSB at 28 days ranged from 22 to 40 MPa. The indoor thermal performance test revealed that concrete with macro-encapsulated octadecane-HSB was capable of reducing the peak indoor air temperature and the fluctuation of indoor temperature. It can be very effective in transferring the heating and cooling loads away from the peak demand times.

  14. U.S. Department of Energy thermal energy storage research activities review: 1989 Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, H.W. [ed.] [PAI Corp., Oak Ridge, TN (United States); Tomlinson, J.J. [ed.] [Oak Ridge National Lab., TN (United States)

    1989-03-01

    Thermal Energy Storage (TES) offers the opportunity for the recovery and re-use of heat currently rejected to the ambient environment. Further, through the ability of TES to match an energy supply with a thermal energy demand, TES increases efficiencies of energy systems and improves capacity factors of power plants. The US Department of Energy has been the leader in TES research, development, and demonstration since recognition in 1976 of the need for fostering energy conservation as a component of the national energy budget. The federal program on TES R and D is the responsibility of the Office of Energy Storage and Distribution within the US Department of Energy (DOE). The overall program is organized into three program areas: diurnal--relating primarily to lower temperature heat for use in residential and commercial buildings on a daily cycle; industrial--relating primarily to higher temperature heat for use in industrial and utility processes on an hourly to daily cycle; seasonal--relating primarily to lower temperature heat or chill for use in residential complexes (central supply as for apartments or housing developments), commercial (light manufacturing, processing, or retail), and industrial (space conditioning) on a seasonal to annual cycle. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  15. Worker health and safety in solar thermal power systems. III. Thermal energy storage subsystems

    Energy Technology Data Exchange (ETDEWEB)

    Ullman, A.Z.; Sokolow, B.B.; Daniels, J.; Hurt, P.

    1979-10-01

    The effects of the use of thermal energy storage (TES) subsystems in solar thermal power systems (STPS) on operating failures and on worker health and safety are examined. Revelant near- and medium-term designs for TES subsystems are reviewed. Generic failure events are considered by an event tree methodology. Three generic categories of initiating events are identified which can lead to release of storage fluids and other hazards. Three TES subsystem designs are selected for, and subjected to, analysis. A fluid release event tree for a sensible heat TES subsystem using mixed media organic oil/crushed rock and sand, designed for the Barstow, CA, 10 MWe pilot plant, is developed. Toxicology and flammability hazards are considered. The effect of component failures, including ullage and fluid maintenance units, on subsystem safety is considered. A latent heat subsystem using NaNO/sub 3//NaOH as the working medium is studied, and relevant failure events delineated. Mechanical equipment failures including the scraped wall heat exchangers, are examined. Lastly, a thermochemical TES subsystem using SO/sub 2//SO/sub 3/ interconversion is considered. Principle hazards identified include mechanical failures and storage fluid release. The integrity of the system is found to depend on catalyst and heat exchanger reliability. Dynamic response to off-normal system events is considered.

  16. Analysis of Large- Capacity Water Heaters in Electric Thermal Storage Programs

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, Alan L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Anderson, David M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Winiarski, David W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carmichael, Robert T. [Cadeo Group, Washington D. C. (United States); Mayhorn, Ebony T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fisher, Andrew R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-17

    This report documents a national impact analysis of large tank heat pump water heaters (HPWH) in electric thermal storage (ETS) programs and conveys the findings related to concerns raised by utilities regarding the ability of large-tank heat pump water heaters to provide electric thermal storage services.

  17. Thermal storage incorporated in the mechanical systems for printing works to offset peak loads

    Energy Technology Data Exchange (ETDEWEB)

    Simmonds, P. [Flack and Kurtz Consulting Engineers, New York, NY (United States); Braam, T. [RTB Van Heugten b.v., Groningen (Netherlands)

    1997-12-31

    The electrical consumption of a printing works can be reduced by utilizing thermal storage to offset loads. In order to achieve a balance between 100% outdoor air and conditioned air, different ventilation schemes were compared. The subsequent cooling load derived from the comparison was further evaluated to see if a chiller plant together with a thermal storage system would reduce energy costs.

  18. Heat transfer characteristics of thermal energy storage system using PCM capsules. A review

    Energy Technology Data Exchange (ETDEWEB)

    Regin, A. Felix; Solanki, S.C.; Saini, J.S. [Department of Mechanical and Industrial Engineering, Indian Institute of Technology Roorkee, Roorkee 247 667 (India)

    2008-12-15

    Thermal energy storage has recently attracted increasing interest related to thermal applications such as space and water heating, waste heat utilization, cooling and air-conditioning. Energy storage is essential whenever there is a mismatch between the supply and consumption of energy. Use of phase change material (PCM) capsules assembled as a packed bed is one of the important methods that has been proposed to achieve the objective of high storage density with higher efficiency. A proper designing of the thermal energy storage systems using PCMs requires quantitative information about heat transfer and phase change processes in PCM. This paper reviews the development of available latent heat thermal energy storage technologies. The different aspects of storage such as material, encapsulation, heat transfer, applications and new PCM technology innovation have been carried out. (author)

  19. Solar Pilot Plant, Phase I. Preliminary design report. Volume V. Thermal storage subsystem. CDRL item 2

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-05-01

    Design, specifications, and diagrams for the thermal storage subsystem for the 10-MW pilot tower focus power plant are presented in detail. The Honeywell thermal storage subsystem design features a sensible heat storage arrangement using proven equipment and materials. The subsystem consists of a main storage containing oil and rock, two buried superheater tanks containing inorganic salts (Hitec), and the necessary piping, instrumentation, controls, and safety devices. The subsystem can provide 7 MW(e) for three hours after twenty hours of hold. It can be charged in approximately four hours. Storage for the commercial-scale plant consists of the same elements appropriately scaled up. Performance analysis and tradeoff studies are included.

  20. Buildings Research using Infrared Imaging Radiometers with Laboratory Thermal Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Griffith, Brent; Arasteh, Dariush

    1999-01-12

    Infrared thermal imagers are used at Lawrence Berkeley National Laboratory to study heat transfer through components of building thermal envelopes. Two thermal chambers maintain steady-state heat flow through test specimens under environmental conditions for winter heating design. Infrared thermography is used to map surface temperatures on the specimens' warm side. Features of the quantitative thermography process include use of external reference emitters, complex background corrections, and spatial location markers. Typical uncertainties in the data are {+-} 0.5 C and 3 mm. Temperature controlled and directly measured external reference emitters are used to correct data from each thermal image. Complex background corrections use arrays of values for background thermal radiation in calculating temperatures of self-viewing surfaces. Temperature results are used to validate computer programs that predict heat flow including Finite-Element Analysis (FEA) conduction simulations and conjugate Computational Fluid Dynamics (CFD) simulations. Results are also used to study natural convection surface heat transfer. Example data show the distribution of temperatures down the center line of an insulated window.

  1. ALARA Analysis for Shippingport Pressurized Water Reactor Core 2 Fuel Storage in the Canister Storage Building (CSB)

    CERN Document Server

    Lewis, M E

    2000-01-01

    The addition of Shippingport Pressurized Water Reactor (PWR) Core 2 Blanket Fuel Assembly storage in the Canister Storage Building (CSB) will increase the total cumulative CSB personnel exposure from receipt and handling activities. The loaded Shippingport Spent Fuel Canisters (SSFCs) used for the Shippingport fuel have a higher external dose rate. Assuming an MCO handling rate of 170 per year (K East and K West concurrent operation), 24-hr CSB operation, and nominal SSFC loading, all work crew personnel will have a cumulative annual exposure of less than the 1,000 mrem limit.

  2. Program definition and assessment overview. [for thermal energy storage project management

    Science.gov (United States)

    Gordon, L. H.

    1980-01-01

    The implementation of a program level assessment of thermal energy storage technology thrusts for the near and far term to assure overall coherent energy storage program is considered. The identification and definition of potential thermal energy storage applications, definition of technology requirements, and appropriate market sectors are discussed along with the necessary coordination, planning, and preparation associated with program reviews, workshops, multi-year plans and annual operating plans for the major laboratory tasks.

  3. Testing of High Thermal Cycling Stability of Low Strength Concrete as a Thermal Energy Storage Material

    Directory of Open Access Journals (Sweden)

    Chao Wu

    2016-09-01

    Full Text Available Concrete has the potential to become a solution for thermal energy storage (TES integrated in concentrating solar power (CSP systems due to its good thermal and mechanical properties and low cost of material. In this study, a low strength concrete (C20 is tested at high temperatures up to 600 °C. Specimens are thermally cycled at temperatures in the range of 400–300 °C, 500–300 °C, and 600–300 °C, which TES can reach in operation. For comparison, specimens also cycled at temperature in the range of 400–25 °C (room temperature, 500–25 °C, and 600–25 °C. It is found from the test results that cracks are not observed on the surfaces of concrete specimens until the temperature is elevated up to 500 °C. There is mechanical deterioration of concrete after exposure to high temperature, especially to high thermal cycles. The residual compressive strength of concrete after 10 thermal cycles between 600 °C and 300 °C is about 58.3%, but the specimens remain stable without spalling, indicating possible use of low strength concrete as a TES material.

  4. Seasonal thermal energy storage in shallow geothermal systems: thermal equilibrium stage

    Directory of Open Access Journals (Sweden)

    Nowamooz Hossein

    2016-01-01

    Full Text Available This paper is dedicated to the study of seasonal heat storage in shallow geothermal installations in unsaturated soils for which hydrothermal properties such as degree of saturation and thermal conductivity vary with time throughout the profile. In the model, a semi-analytical model which estimates time-spatial thermal conductivity is coupled with a 2D cylindrical heat transfer modeling using finite difference method. The variation of temperature was obtained after 3 heating and cooling cycles for the different types of loads with maximum thermal load of qmax = 15 W.m−1 with variable angular frequency (8 months of heating and 4 months of cooling.and constant angular frequency (6 months of heating and 6 months of cooling to estimate the necessary number of cycles to reach the thermal equilibrium stage. The results show that we approach a thermal equilibrium stage where the same variation of temperature can be observed in soils after several heating and cooling cycles. Based on these simulations, the necessary number of cycles can be related to the total applied energy on the system and the minimum number of cycles is for a system with the total applied energy of 1.9qmax.

  5. Research and Development for Novel Thermal Energy Storage Systems (TES) for Concentrating Solar Power (CSP)

    Energy Technology Data Exchange (ETDEWEB)

    Faghri, Amir; Bergman, Theodore L; Pitchumani, Ranga

    2013-09-26

    The overall objective was to develop innovative heat transfer devices and methodologies for novel thermal energy storage systems for concentrating solar power generation involving phase change materials (PCMs). Specific objectives included embedding thermosyphons and/or heat pipes (TS/HPs) within appropriate phase change materials to significantly reduce thermal resistances within the thermal energy storage system of a large-scale concentrating solar power plant and, in turn, improve performance of the plant. Experimental, system level and detailed comprehensive modeling approaches were taken to investigate the effect of adding TS/HPs on the performance of latent heat thermal energy storage (LHTES) systems.

  6. Evaluation of thermal energy storage for the proposed Twin Cities District Heating system. [using cogeneration heat production and aquifiers for heat storage

    Science.gov (United States)

    Meyer, C. F.

    1980-01-01

    The technical and economic feasibility of incorporating thermal energy storage components into the proposed Twin Cities District heating project was evaluated. The technical status of the project is reviewed and conceptual designs of district heating systems with and without thermal energy storage were compared in terms of estimated capital requirements, fuel consumption, delivered energy cost, and environmental aspects. The thermal energy storage system is based on cogeneration and the storage of heat in aquifers.

  7. A numerical study of latent thermal energy storage in a phase change material/carbon panel

    Science.gov (United States)

    Mekaddem, Najoua; Ali, Samia Ben; Mazioud, Atef; Hannachi, Ahmed

    2016-07-01

    To reduce the energetic dependence of building, it has become necessary to explore and develop new materials promoting energy conservation. Because of their high storage capacity, phase change materials (PCMs) are efficient to store thermal energy. In this paper, a 3D model was studied for simulation of energy storing cycles to predict the performances of PCM loaded panels. Carbon was used as supporting material for the PCM. The simulation was based on the enthalpy method using Ansys Fluent software. The panel was exposed to a daily heat flow including the effects of convection and radiation. The results show that the temperature decreased of approximately 2.5°C with a time shift about 2 hours. The steady state was reached after four cycles. Thus, after four cycles the PCM showed its effects on the temperature conditioning.

  8. Comparison of Buildings\\' Thermal Loads against Building Orientations for Sustainable Housing in Pakistan

    Directory of Open Access Journals (Sweden)

    Arif Khan

    2012-07-01

    Full Text Available As the sustainable settlements have been included as a vital end product of all planning exercises, the architectural layouts should be well integrated with the sun path charts and the orientations of windows. Appropriate orientations can offer thermally indoor conditions besides physical and psychological comfort in any settlement at lesser energy demand. This investigation uses a vast number of computer simulations to visualize and make better decisions about heating and cooling requirements of a building and facades as a function of window orientation in composite climatic condition of Lahore. This study in particular evaluates the solar load in residential buildings responsive to the objective of sustainable new housing leading to thoughtful integration of architecture. The orientation of the buildings could then be essentially integrated to the current architectural and urban design practices in order to optimize the relationship between the given site ant the orientations for sustainable developments.

  9. The impact of low-temperature seasonal aquifer thermal energy storage (SATES) systems on chlorinated solvent contaminated groundwater: Modeling of spreading and degradation

    NARCIS (Netherlands)

    Zuurbier, K.G.; Hartog, N.; Valstar, J.; Post, V.E.A.; Breukelen, B.M. van

    2013-01-01

    Groundwater systems are increasingly used for seasonal aquifer thermal energy storage (SATES) for periodic heating and cooling of buildings. Its use is hampered in contaminated aquifers because of the potential environmental risks associated with the spreading of contaminated groundwater, but positi

  10. Experimental simulation of latent heat thermal energy storage and heat pipe thermal transport for dish concentrator solar receiver

    Science.gov (United States)

    Narayanan, R.; Zimmerman, W. F.; Poon, P. T. Y.

    1981-01-01

    Test results on a modular simulation of the thermal transport and heat storage characteristics of a heat pipe solar receiver (HPSR) with thermal energy storage (TES) are presented. The HPSR features a 15-25 kWe Stirling engine power conversion system at the focal point of a parabolic dish concentrator operating at 827 C. The system collects and retrieves solar heat with sodium pipes and stores the heat in NaF-MgF2 latent heat storage material. The trials were run with a single full scale heat pipe, three full scale TES containers, and an air-cooled heat extraction coil to replace the Stirling engine heat exchanger. Charging and discharging, constant temperature operation, mixed mode operation, thermal inertial, etc. were studied. The heat pipe performance was verified, as were the thermal energy storage and discharge rates and isothermal discharges.

  11. Thermal properties of a novel nanoencapsulated phase change material for thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Fuensanta, Mónica, E-mail: monica.fuensanta@aidico.es [AIDICO, Technological Institute of Construction, Camí de Castella, 4, 03660 Novelda, Alicante (Spain); Paiphansiri, Umaporn [Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz (Germany); Romero-Sánchez, María Dolores, E-mail: md.romero@aidico.es [AIDICO, Technological Institute of Construction, Camí de Castella, 4, 03660 Novelda, Alicante (Spain); Guillem, Celia; López-Buendía, Ángel M. [AIDICO, Technological Institute of Construction, Camí de Castella, 4, 03660 Novelda, Alicante (Spain); Landfester, Katharina [Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz (Germany)

    2013-08-10

    Highlights: • A paraffin wax RT80 was encapsulated in styrene–butyl acrylate copolymer as polymer shell using miniemulsion polymerization process to obtain a novel nanoencapsulated PCM with 80 °C melting temperature. • Nano-PCMs have high compact structure, spherical morphology and thermal stability. • The nano-PCMs have potential applications as thermal energy storage materials. - Abstract: A novel nanoencapsulation of a paraffine type phase change material, RT80, in a styrene–butyl acrylate copolymer shell using the miniemulsion polymerization process was carried out. General characteristics of the RT80 nanoparticles in terms of thermal properties, morphology, chemical composition and particle size distribution were characterized by Differential Scanning Calorimetry (DSC), Thermal Gravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FT-IR) and Dynamic Light Scattering (DLS). The influence of different monomers (styrene, butyl acrylate) and the surfactant/paraffin mass ratios on nanoparticles properties such as thermal capacity, particle size and morphology were systematically investigated. In all cases studied, encapsulation efficiency was close to 80 wt% with a particle size distribution between 52 and 112 nm and regular spherical shape and uniform structure. The amount of encapsulated paraffin achieved was comprised between 8 and 20%. Melting and crystallization heats were found to be approximately 5–25 J g{sup −1}, mainly depending on surfactant/paraffin mass ratio. Melting temperature of RT80 nanoparticles slightly decreased (1–7 °C) respect to the raw RT80. In addition, the encapsulated RT80 nanoparticles show thermal stability even after 200 thermal (heat-cooling) cycles.

  12. Thermal performance of integration of solar collectors and building envelopes

    Institute of Scientific and Technical Information of China (English)

    于国清; 龚小辉; 曹双华

    2009-01-01

    The integration of building with solar collector was studied. The theoretical model of integration of building envelopes and flat plate solar collectors was set up and the thermal performance of integration was studied in winter and summer,and compared to envelopes without solar collectors. The results show that the solar collection efficiency is raised in the integration of building envelopes and solar collectors with the air layer doors closed. This is true whether in winter or summer. The increment is higher as the inlet water temperature increases or the ambient temperature is low. In winter,the heat loss is significantly reduced through integration of the building envelopes and solar collectors with the closed air layer doors. The integration with the open air layer door is worse than that without collectors. In summer,the heat gains of the integration of envelopes and solar collectors are more obviously reduced than envelopes without collectors,the integration with the open air layer door is a little better than the closed one,but the difference is very small.

  13. Simulation and experimental study of thermal performance of a building roof with a phase change material (PCM)

    Indian Academy of Sciences (India)

    A Mannivannan; M T Jaffarsathiq Ali

    2015-12-01

    Latent heat storage in a phase change material (PCM) is very attractive because of its high-energy storage density and its isothermal behaviour during the phase change process. Low thermal conductivity of the walls and roof reduces the heat gain at a steady state condition. Chloride hexahydrate (CaCl26H2O) as a phase change material (PCM) for a room was proposed in this paper to control the indoor air temperature for a better thermal comfort for human beings. Building concrete roof with vertical cylindrical hole of 0.5 $\\times$ 0.5 m and array of 3 $\\times$ 3 filled with phase change material (PCM) was considered for analysis. A detailed thermal analysis was carried by both simulation and experimental study. Results showed that this type of PCM room can decrease the indoor air temperature fluctuation by a maximum of 4°C.

  14. Structural analyses of the storage container for heavy element facility, building-251

    Energy Technology Data Exchange (ETDEWEB)

    Ng, D S

    1999-01-01

    The Heavy Element Facility, Building 251, contains a series of underground storage vaults which are used for long term storage of nuclear materials. A storage rack with shelves is suspended from the top of each storage vault. The stainless steel containers enclosing the nuclear materials are stored on the shelves. A Hazard & Accident assessment analyzed the vulnerability of this storage system to assaults resulting from natural phenomena and accidents within the building. The assessment considered all racks and their containers to be stored underground and secured in their static, long-term configuration. Moving beyond the static, long-term hazard assessment, the structural analyses were performed to evaluate the storage container against a rare, short duration event. An accidental free drop of a container may occur in a combination of two events: a rare, short-duration earthquake concurrent with an operation of raising the storage rack to a maximum height that the crane is capable of. This hypothetical free drop may occur only to the container in the uppermost shelf of the storage rack. The analyses were the structural evaluation of the storage container to determine the material containment integrity of the storage container after the accident. The evaluation was performed simulating a free drop from the storage rack, with a maximum load in the container, striking/an unyielding surface in the worst orientation. The analyses revealed that, in the very unlikely event of a container drop, the integrity of the hermetic seal of the storage container could be compromised due to plastic deformation of the lid and mating flange. Simple engineering and administrative controls can prevent that from occurring.

  15. FY 17 Q1 Commercial integrated heat pump with thermal storage milestone report

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Heiba, Ahmad [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Baxter, Van D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rice, C. Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-01-01

    The commercial integrated heat pump with thermal storage (AS-IHP) offers significant energy saving over a baseline heat pump with electric water heater. The saving potential is maximized when the AS-IHP serves coincident high water heating and high space cooling demands. A previous energy performance analysis showed that the AS-IHP provides the highest benefit in the hot-humid and hot-dry/mixed dry climate regions. Analysis of technical potential energy savings for these climate zones based on the BTO Market calculator indicated that the following commercial building market segments had the highest water heating loads relative to space cooling and heating loads education, food service, health care, lodging, and mercantile/service. In this study, we focused on these building types to conservatively estimate the market potential of the AS-IHP. Our analysis estimates maximum annual shipments of ~522,000 units assuming 100% of the total market is captured. An early replacement market based on replacement of systems in target buildings between 15 and 35 years old was estimated at ~136,000 units. Technical potential energy savings are estimated at ~0.27 quad based on the maximum market estimate, equivalent to ~13.9 MM Ton CO2 emissions reduction.

  16. Dish Stirling High Performance Thermal Storage FY14Q4 Quad Chart

    Energy Technology Data Exchange (ETDEWEB)

    Andraka, Charles E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-10-01

    The goals of this project are to demonstrate the feasibility of significant thermal storage for dish stirling systems to leverage their existing high performance to greater capacity; demonstrate key components of a latent storage and transport system enabling on-dish storage with low energy losses; and provide a technology path to a 25kWe system with 6 hours of storage.

  17. The impact of indoor thermal conditions, system controls and building types on the building energy demand

    Energy Technology Data Exchange (ETDEWEB)

    Corgnati, Stefano Paolo; Fabrizio, Enrico; Filippi, Marco [Dipartimento di Energetica (DENER), Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

    2008-07-01

    It is possible to evaluate the energy demand as well as the parameters related to indoor thermal comfort through building energy simulation tools. Since energy demand for heating and cooling is directly affected by the required level of thermal comfort, the investigation of the mutual relationship between thermal comfort and energy demand (and therefore operating costs) is of the foremost importance both to define the benchmarks for energy service contracts and to calibrate the energy labelling according to European Directive 2002/92/CE. The connection between indoor thermal comfort conditions and energy demand for both heating and cooling has been analyzed in this work with reference to a set of validation tests (office buildings) derived from a European draft standard. Once a range of required acceptable indoor operative temperatures had been fixed in accordance with Fanger's theory (e.g. -0.5 < PMV < -0.5), the effective hourly comfort conditions and the energy consumptions were estimated through dynamic simulations. The same approach was then used to quantify the energy demand when the range of acceptable indoor operative temperatures was fixed in accordance with de Dear's adaptive comfort theory. (author)

  18. Numerical Investigation of Effective Heat Conductivity of Fluid in Charging Process of Thermal Storage Tank

    OpenAIRE

    Taheri, H.; Schmidt, F. P.; Gabi, M.

    2015-01-01

    This paper presents a numerical case study of heat transfer mechanisms during the charging process of a stratified thermal storage tank applied in a specific adsorption heat pump cycle. The effective thermal conductivity of the heat transfer fluid during the charging process is analyzed through CFD simulations using Unsteady Reynolds-averaged Navier-Stokes equations (URANS). The aim of the study is to provide an equivalent thermal conductivity for a one-dimensional storage tank model to be us...

  19. Sintering Densification Mechanism of Talc on Promoting Thermal Storage Andalusite Ceramics in Solar Thermal Power Generation

    Institute of Scientific and Technical Information of China (English)

    WU Jianfeng; CHENG Hao; XU Xiaohong; LAO Xinbing; ZHANG Yinfeng; RAO Zhengang; DENG Tengfei

    2015-01-01

    Mullite ceramic, as one of high-performance thermal storage ceramics for solar thermal power generation systems, wasin-situ fabricated with talc as a sintering aid via semi-dry pressing and pressureless sintering in air. The mullitization influence of talc as a sintering aid on the formation of andalusite was investigated, and its mechanism to promote the sintering densification of samples was analyzed. The results show that talc reacts with corundum at a low temperature toin-situ produce cordierite. Cordierite reactsin-situ to produce mullite and glass phase, which reduces the sintering temperature sharply when corundum reacts with rich silicon fluid directly and generates secondary mullite. Cordierite resolves and produces magnesium oxide liquid phase, which contains active aluminium oxide lattice capable of reducing reaction activation energy and promoting remaining corundum to react with rich silicon fluid and produces secondary mullite.

  20. Sintering Densification Mechanism of Talc on Promoting Thermal Storage Andalusite Ceramics in Solar Thermal Power Generation

    Institute of Scientific and Technical Information of China (English)

    WU; Jianfeng; CHENG; Hao; XU; Xiaohong; LAO; Xinbing; ZHANG; Yinfeng; RAO; Zhengang; DENG; Tengfei

    2015-01-01

    Mullite ceramic,as one of high-performance thermal storage ceramics for solar thermal power generation systems,was in-situ fabricated with talc as a sintering aid via semi-dry pressing and pressureless sintering in air.The mullitization influence of talc as a sintering aid on the formation of andalusite was investigated,and its mechanism to promote the sintering densification of samples was analyzed.The results show that talc reacts with corundum at a low temperature to in-situ produce cordierite.Cordierite reacts in-situ to produce mullite and glass phase,which reduces the sintering temperature sharply when corundum reacts with rich silicon fluid directly and generates secondary mullite.Cordierite resolves and produces magnesium oxide liquid phase,which contains active aluminium oxide lattice capable of reducing reaction activation energy and promoting remaining corundum to react with rich silicon fluid and produces secondary mullite.

  1. Thermal performance analysis of a thermocline thermal energy storage system with FLiNaK molten salt

    Science.gov (United States)

    Liu, C.; Cheng, M. S.; Zhao, B. C.; Dai, Z. M.

    2017-01-01

    A thermocline thermal storage unit with a heat transfer fluid (HTF) of high-temperature molten salt is considered as one of the most promising methods of thermal storage due to its lower cost and smaller size. The main objective of this work is to analyze the transient behavior of the available molten salt FLiNaK used as the HTF in heat transfer and heat storage in a thermocline thermal energy storage (TES) system. Thermal characteristics including temperature profiles influenced by different inlet velocities of HTF and different void fractions of porous heat storage medium are analyzed. The numerical investigation on the heat storage and heat transfer characteristics of FLiINaK has been carried out. A comparison between two different molten salts, FLiNaK and Hitec, has been explored in this paper with regards to their charging and discharging operations. The results indicate the system with FLiNaK has a greater energy storage capability, a shorter charging time and a higher output power. The numerical investigation reveals heat storage and heat transfer characteristics of the thermocline TES system with FLiNaK, and provide important references for molten salt selection of the TES system in the future.

  2. Preparation, Mechanical and Thermal Properties of Cement Board with Expanded Perlite Based Composite Phase Change Material for Improving Buildings Thermal Behavior

    Directory of Open Access Journals (Sweden)

    Rongda Ye

    2015-11-01

    Full Text Available Here we demonstrate the mechanical properties, thermal conductivity, and thermal energy storage performance of construction elements made of cement and form-stable PCM-Rubitherm® RT 28 HC (RT28/expanded perlite (EP composite phase change materials (PCMs. The composite PCMs were prepared by adsorbing RT28 into the pores of EP, in which the mass fraction of RT28 should be limited to be no more than 40 wt %. The adsorbed RT28 is observed to be uniformly confined into the pores of EP. The phase change temperatures of the RT28/EP composite PCMs are very close to that of the pure RT28. The apparent density and compression strength of the composite cubes increase linearly with the mass fraction of RT28. Compared with the thermal conductivity of the boards composed of cement and EP, the thermal conductivities of the composite boards containing RT28 increase by 15%–35% with the mass fraction increasing of RT28. The cubic test rooms that consist of six boards were built to evaluate the thermal energy storage performance, it is found that the maximum temperature different between the outside surface of the top board with the indoor temperature using the composite boards is 13.3 °C higher than that of the boards containing no RT28. The thermal mass increase of the built environment due to the application of composite boards can contribute to improving the indoor thermal comfort and reducing the energy consumption in the buildings.

  3. Phase-change material as a thermal storage media

    Energy Technology Data Exchange (ETDEWEB)

    El Chazly, Nihad M; Khattab, Nagwa M [Dokki, Cairo (Egypt)

    2000-07-01

    Heat storage based on the sensible heating of media such as water, rock and earth represent the first generation of solar energy storage subsystems and technology for their utilization. However, recently the heat storage based on the latent heat associated with a change in phase of a material offers many advantages over sensible heat storage. The most important characteristic of such a subsystem is its a sufficient storage capacity. An idealized model visualizing a thermal capacitor using a phase change material is constructed and subjected to simulated solar system environmental conditions. The proposed model is of a flat plate geometry consisting of two panels compartments forming the body of the capacitor containing the paraffin, leaving at their inner surfaces a thin passage allowing the water flow. The whole structure was assumed to be insulated to minimize heat loss. An analysis of the model is conducted using Goodman technique to generate data about the temperature distribution, the melt thickness, and the heat stored in the PCM under conditions of: ( i ) constant mass flow rate tests for various water inlet temperatures and ( ii ) constant water inlet temperature for various mass flow rate. A FORTRAN computer program was constructed to perform the analysis. It was found the water outlet temperature increases with time until it becomes nearly equals to the inlet temperature. Increasing the mass flow rate for a given inlet temperature, decreases the time required for outlet temperature to reach a given value. Increasing inlet temperature for a given mass flow rate gives a very rapid decrease in the time required for the outlet water temperature to reach a given value. Instantaneous rate of heat storage was determined from the inlet-to- exit temperature differential and measured flow rate. This rate was then integrated numerically to determine the cumulative total energy stored as a function of time. It was found that the instantaneous rate of heat storage

  4. Analysis of thermal energy storage for a pharmaceutical company

    Energy Technology Data Exchange (ETDEWEB)

    Henze, Gregor P. [Colorado Univ., Boulder, CO (US). Dept. of Civil, Environmental and Architectural Engineering (CEAE); Biffar, Bernd; Wienecke, Marcus [Boehringer Ingelheim Pharma GmbH und Co. KG, Biberach (Germany); Becker, Martin P. [Biberach Univ. of Applied Sciences (Germany). Dept. of Architectural and Energy Engineering

    2009-07-01

    A pharmaceutical facility located in Southern Germany is experiencing a trend of growing cooling loads to be met by the chilled water plant composed of ten chillers of greatly varying cost effectiveness. With a capacity shortfall inevitable, the question arises whether to install an additional chiller or improve the utilization of the existing chillers, in particular those with low operating costs per unit cooling, through the addition of a chilled water thermal energy storage (TES) system. To provide decision support in this matter, an optimization environment was developed and validated that adopts mixed integer programming as the approach to optimizing the chiller dispatch for any load condition, while an overarching dynamic programming based optimization approach optimizes the charge/discharge strategy of the TES system. In this fashion, the chilled water plant optimization is decoupled but embedded in the TES control optimization. The approach was selected to allow for arbitrary constraints and optimization horizons, while ensuring a global optimum to the problem. The results show that a relatively small TES tank provides significant economic and operational benefits. Yet, in order to facilitate long-term supply security, a larger TES tank capacity was decided on and the TES system was constructed in 2008. (orig.)

  5. Thermal energy storage systems using fluidized bed heat exchangers

    Science.gov (United States)

    Weast, T.; Shannon, L.

    1980-06-01

    A rotary cement kiln and an electric arc furnace were chosen for evaluation to determine the applicability of a fluid bed heat exchanger (FBHX) for thermal energy storage (TES). Multistage shallow bed FBHX's operating with high temperature differences were identified as the most suitable for TES applications. Analysis of the two selected conceptual systems included establishing a plant process flow configuration, an operational scenario, a preliminary FBHX/TES design, and parametric analysis. A computer model was developed to determine the effects of the number of stages, gas temperatures, gas flows, bed materials, charge and discharge time, and parasitic power required for operation. The maximum national energy conservation potential of the cement plant application with TES is 15.4 million barrels of oil or 3.9 million tons of coal per year. For the electric arc furnance application the maximum national conservation potential with TES is 4.5 million barrels of oil or 1.1 million tons of coal per year. Present time of day utility rates are near the breakeven point required for the TES system. Escalation of on-peak energy due to critical fuel shortages could make the FBHX/TES applications economically attractive in the future.

  6. Relationship of regional water quality to aquifer thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.

    1983-11-01

    Ground-water quality and associated geologic characteristics may affect the feasibility of aquifer thermal energy storage (ATES) system development in any hydrologic region. This study sought to determine the relationship between ground-water quality parameters and the regional potential for ATES system development. Information was collected from available literature to identify chemical and physical mechanisms that could adversely affect an ATES system. Appropriate beneficiation techniques to counter these potential geochemical and lithologic problems were also identified through the literature search. Regional hydrology summaries and other sources were used in reviewing aquifers of 19 drainage regions in the US to determine generic geochemical characteristics for analysis. Numerical modeling techniques were used to perform geochemical analyses of water quality from 67 selected aquifers. Candidate water resources regions were then identified for exploration and development of ATES. This study identified six principal mechanisms by which ATES reservoir permeability may be impaired: (1) particulate plugging, (2) chemical precipitation, (3) liquid-solid reactions, (4) formation disaggregation, (5) oxidation reactions, and (6) biological activity. Specific proven countermeasures to reduce or eliminate these effects were found. Of the hydrologic regions reviewed, 10 were identified as having the characteristics necessary for ATES development: (1) Mid-Atlantic, (2) South-Atlantic Gulf, (3) Ohio, (4) Upper Mississippi, (5) Lower Mississippi, (6) Souris-Red-Rainy, (7) Missouri Basin, (8) Arkansas-White-Red, (9) Texas-Gulf, and (10) California.

  7. Pseudo-Bond Graph model for the analysis of the thermal behavior of buildings

    Directory of Open Access Journals (Sweden)

    Merabtine Abdelatif

    2013-01-01

    Full Text Available In this work, a simplified graphical modeling tool, which in some extent can be considered in halfway between detailed physical and Data driven dynamic models, has been developed. This model is based on Bond Graphs approach. This approach has the potential to display explicitly the nature of power in a building system, such as a phenomenon of storage, processing and dissipating energy such as Heating, Ventilation and Air-Conditioning (HVAC systems. This paper represents the developed models of the two transient heat conduction problems corresponding to the most practical cases in building envelope, such as the heat transfer through vertical walls, roofs and slabs. The validation procedure consists of comparing the results obtained with this model with analytical solution. It has shown very good agreement between measured data and Bond Graphs model simulation. The Bond Graphs technique is then used to model the building dynamic thermal behavior over a single zone building structure and compared with a set of experimental data. An evaluation of indoor temperature was carried out in order to check our Bond Graphs model.

  8. Simulation of a high temperature thermal energy storage system employing several families of phase-change storage material

    Energy Technology Data Exchange (ETDEWEB)

    Adebiyi, G.A. [Mississippi State Univ., MS (United States)

    1989-03-01

    Previous work by the author entailed modeling of the Packed Bed Thermal Energy Storage System, utilizing Phase-Change Materials, and a performance evaluation of the system based on the Second Law of thermodynamics. A principal conclusion reached is that the use of a single family of phase-change storage material may not in fact produce a thermodynamically superior system relative to one utilizing sensible heat storage material. This prompted us to modify our model so that we could investigate whether or not a significantly improved performance may be achieved via the use of multiple families of phase-change materials instead. Other factors investigated in the present work include the effect on system performance due to the thermal mass of the containment vessel wall, varying temperature and mass flow rate of the flue gas entering the packed bed during the storage process, and thermal radiation which could be a significant factor at high temperature levels. The resulting model is intended to serve as an integral part of a real-time simulation of the application of a high temperature regenerator in a periodic brick plant. This paper describes the more comprehensive model of the high temperature thermal energy storage system and presents results indicating that improved system performance could be achieved via a judicious choice of multiple families of phase-change materials.

  9. Empirical Validation of Heat Transfer Performance Simulation of Graphite/PCM Concrete Materials for Thermally Activated Building System

    Directory of Open Access Journals (Sweden)

    Jin-Hee Song

    2017-01-01

    Full Text Available To increase the heat capacity in lightweight construction materials, a phase change material (PCM can be introduced to building elements. A thermally activated building system (TABS with graphite/PCM concrete hollow core slab is suggested as an energy-efficient technology to shift and reduce the peak thermal load in buildings. An evaluation of heat storage and dissipation characteristics of TABS in graphite/PCM concrete has been conducted using dynamic simulations, but empirical validation is necessary to acceptably predict the thermal behavior of graphite/PCM concrete. This study aimed to validate the thermal behavior of graphite/PCM concrete through a three-dimensional transient heat transfer simulation. The simulation results were compared to experimental results from previous studies of concrete and graphite/PCM concrete. The overall thermal behavior for both materials was found to be similar to experiment results. Limitations in the simulation modeling, which included determination of the indoor heat transfer coefficient, assumption of constant thermal conductivity with temperature, and assumption of specimen homogeneity, led to slight differences between the measured and simulated results.

  10. Monitoring water storage variations in the vadose zone with gravimeters - quantifying the influence of observatory buildings

    Science.gov (United States)

    Reich, Marvin; Güntner, Andreas; Mikolaj, Michal; Blume, Theresa

    2016-04-01

    Time-lapse ground-based measurements of gravity have been shown to be sensitive to water storage variations in the surroundings of the gravimeter. They thus have the potential to serve as an integrative observation of storage changes in the vadose zone. However, in almost all cases of continuous gravity measurements, the gravimeter is located within a building which seals the soil beneath it from natural hydrological processes like infiltration and evapotranspiration. As water storage changes in close vicinity of the gravimeter have the strongest influence on the measured signal, it is important to understand the hydrology in the unsaturated soil zone just beneath the impervious building. For this reason, TDR soil moisture sensors were installed in several vertical profiles up to a depth of 2 m underneath the planned new gravimeter building at the Geodetic Observatory Wettzell (southeast Germany). In this study, we assess the influence of the observatory building on infiltration and subsurface flow patterns and thus the damping effect on gravimeter data in a two-way approach. Firstly, soil moisture time series of sensors outside of the building area are correlated with corresponding sensors of the same depth beneath the building. The resulting correlation coefficients, time lags and signal to noise relationships are used to find out how and where infiltrating water moves laterally beneath the building and towards its centre. Secondly, a physically based hydrological model (HYDRUS) with high discretization in space and time is set up for the 20 by 20 m area around and beneath the gravimeter building. The simulated spatial distribution of soil moisture in combination with the observed point data help to identify where and to what extent water storage changes and thus mass transport occurs beneath the building and how much this differs to the dynamics of the surroundings. This allows to define the umbrella space, i.e., the volume of the vadose zone where no mass

  11. Moisture storage parameters of porous building materials as time-dependent properties

    Science.gov (United States)

    Záleská, Martina; Pavlíková, Milena; Pavlík, Zbyšek

    2016-06-01

    Three different types of bricks and two different types of sandstones are studied in terms of measurement moisture storage parameters for over-hygroscopic moisture area using pressure plate device. For researched materials, basic physical properties as bulk density, matrix density and total open porosity are determined. From the obtained data of moisture storage measurement, the water retention curves and curves of degree of saturation in dependence on suction pressure are constructed. Water retention curve (also called suction curve, capillary potential curve, capillary-pressure function and capillary-moisture relationship) is the basic material property used in models for simulation of moisture storage in porous building materials.

  12. Low temperature thermal energy storage: a state-of-the-art survey

    Energy Technology Data Exchange (ETDEWEB)

    Baylin, F.

    1979-07-01

    The preliminary version of an analysis of activities in research, development, and demonstration of low temperature thermal energy storage (TES) technologies having applications in renewable energy systems is presented. Three major categories of thermal storage devices are considered: sensible heat; phase change materials (PCM); and reversible thermochemical reactions. Both short-term and annual thermal energy storage technologies based on prinicples of sensible heat are discussed. Storage media considered are water, earth, and rocks. Annual storage technologies include solar ponds, aquifers, and large tanks or beds of water, earth, or rocks. PCM storage devices considered employ salt hydrates and organic compounds. The sole application of reversible chemical reactions outlined is for the chemical heat pump. All program processes from basic research through commercialization efforts are investigated. Nongovernment-funded industrial programs and foreign efforts are outlined as well. Data describing low temperature TES activities are presented also as project descriptions. Projects for all these programs are grouped into seven categories: short-term sensible heat storage; annual sensible heat storage; PCM storage; heat transfer and exchange; industrial waste heat recovery and storage; reversible chemical reaction storage; and models, economic analyses, and support studies. Summary information about yearly funding and brief descriptions of project goals and accomplishments are included.

  13. Space heating in buildings: thermal diagnosis of an industrial building; Chauffage des batiments: bilan thermique d`un batiment industriel

    Energy Technology Data Exchange (ETDEWEB)

    Brunet, R.

    1996-12-31

    The various heat transfer equations used for calculations in thermal diagnosis of an industrial building are reviewed: calculation of the heat losses through walls as a function of building materials, calculation of the energy consumption for heating fresh air (as a function of the air pollution rate in the building), calculation of the total heat losses, the heating energy demand and the annual energy consumption. Data concerning building materials characteristics, insulation and heating loads in the various regions of France, are also presented

  14. Thermal Performance of Building Roof with Infrared Reflective Coatings

    Institute of Scientific and Technical Information of China (English)

    SHEN Hui; TAN Hong-wei; KATSUO MIKI; LIU Xiao-yu

    2009-01-01

    This paper investigated the applicability and effects of infrared reflective coating on energy con-sumption of factory building in hot summer and warm winter zone. It first resorted to theoretical calculation, which demonstrated the beneficial effects of infrared reflective coating on reducing building energy consumption. Then it analyzed a field measurement done on two identical rooms respectively with ordinary coated roof and in-frared reflective coated roof from November 2006 to October 2007, on a 24h basis. The measured data include exterior and interior roof surface temperature, indoor air temperature, and indoor globe temperature. The relat-ed weather data is from a weather station near the measured area. The continuous measurement has been accom-plished in southern China, and the measured data indicate that roof surface temperature and heat gain are signifi-cantly decreased in summer while slight negative effects in winter are induced by adopting infrared reflective coating. Thus it is simple and applicable to reduce building energy consumption in this area by applying infrared reflective coating. Regress equation between reduced roof thermal property, such as surface temperature and heat gain, and reduction in absorbed solar radiation shows their highly linear relationship. Based on the mea-sured data, it is estimated that the reduced power consumption is 3.45 kWh/m2·month in June.

  15. Base-load solar thermal power using thermochemical energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Luzzi, A.; Lovegrove, K. [Australian National Univ., Canberra, ACT (Australia); Filippi, E. [Ammonia Casale, Lugano (Switzerland); Fricker, H. [FC Consulting, Rickenbach (Switzerland); Schmitz-Goeb, M. [L and C Steinmuller GmbH, Process Engineering Div., Gummersbach (Germany); Chandapillai, M. [Siemens Power Generation Asia Pacific Sdn, Bhd., Industrial Power Plants, Kuala Lumpur (Malaysia)

    1999-03-01

    Using a closed-loop thermochemical system based on the reversible ammonia reaction is one of the possible ways for building solar thermal power systems capable of providing electricity on a 24-hour basis without the need for any fossil fuel back-up. In a collaborative effort between industrial and academic partners from Australia, Switzerland, Germany and Malaysia, a study was undertaken to examine the techno-economic viability of this solar concept by formulating a preliminary design for a hypothetical 10 MW{sub e} demonstration system in Central Australia. It was found that a carefully designed demonstration solar power plant, which dominantly uses proven and standard materials, components and technologies, is likely to cost of the order of AUD 157 million and operate with a net solar-to-electric conversion efficiency of 18% and a capacity factor of 80%. This will result in leveled electricity costs (LEC) of about AUD 0.24 per kWh{sub e}. (authors)

  16. A Study of Solar Thermal Propulsion System Enhancement via Thermal Storage and Thermal-electric Conversion

    Science.gov (United States)

    2010-03-24

    Brayton cycle and free piston Stirling cycle). These systems have been thoroughly reviewed elsewhere and will only be briefly discussed here. 24-27...thermal-to-electric conversion systems consists of a hot cathode which thermionically emits electrons over a potential energy barrier to a cooler anode to... Stirling cycle is an efficient and simple system that is typically lightweight and doesn’t require lubricants or high-pressure seals. Sunpower is

  17. Experimental Evaluation of Simple Thermal Storage Control Strategies in Low-Energy Solar Houses to Reduce Electricity Consumption during Grid On-Peak Periods

    Directory of Open Access Journals (Sweden)

    Kyoung-Ho Lee

    2015-08-01

    Full Text Available There is growing interest in zero-energy and low-energy buildings, which have a net energy consumption (on an annual basis of almost zero. Because they can generate both electricity and thermal energy through the use of solar photovoltaic (PV and solar thermal collectors, and with the help of reduced building thermal demand, low-energy buildings can not only make a significant contribution to energy conservation on an annual basis, but also reduce energy consumption and peak demand. This study focused on electricity consumption during the on-peak period in a low-energy residential solar building and considers the use of a building’s thermal mass and thermal storage to reduce electricity consumption in summer and winter by modulation of temperature setpoints for heat pump and indoor thermostats in summer and additional use of a solar heating loop in winter. Experiments were performed at a low-energy solar demonstration house that has solar collectors, hot water storage, a ground-coupled heat pump, and a thermal storage tank. It was assumed that the on-peak periods were from 2 pm to 5 pm on hot summer days and from 5 pm to 8 pm on cold winter days. To evaluate the potential for utilizing the building’s thermal storage capacity in space cooling and heating, the use of simple control strategies on three test days in summer and two test days in the early spring were compared in terms of net electricity consumption and peak demand, which also considered the electricity generation from solar PV modules on the roof of the house.

  18. Innovative Phase Change Thermal Energy Storage Solution for Baseload Power Phase 1 Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Songgang

    2013-05-15

    The primary purpose of this project is to develop and validate an innovative, scalable phase change salt thermal energy storage (TES) system that can interface with Infinia’s family of free-piston Stirling engines (FPSE). This TES technology is also appropriate for Rankine and Brayton power converters. Solar TES systems based on latent heat of fusion rather than molten salt temperature differences, have many advantages that include up to an order of magnitude higher energy storage density, much higher temperature operation, and elimination of pumped loops for most of Infinia’s design options. DOE has funded four different concepts for solar phase change TES, including one other Infinia awarded project using heat pipes to transfer heat to and from the salt. The unique innovation in this project is an integrated TES/pool boiler heat transfer system that is the simplest approach identified to date and arguably has the best potential for minimizing the levelized cost of energy (LCOE). The Phase 1 objectives are to design, build and test a 1-hour TES proof-of-concept lab demonstrator integrated with an Infinia 3 kW Stirling engine, and to conduct a preliminary design of a 12-hour TES on-sun prototype.

  19. Evaluation of existing Hanford buildings for the storage of solid wastes

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, M.C.; Hodgson, R.D.; Sabin, J.C.

    1993-05-01

    Existing storage space at the Hanford Site for solid low-level mixed waste (LLMW) will be filled up by 1997. Westinghouse Hanford Company (WHC) has initiated the project funding cycle for additional storage space to assure that new facilities are available when needed. In the course of considering the funding request, the US Department of Energy (DOE) has asked WHC to identify and review any existing Hanford Site facilities that could be modified and used as an alternative to constructing the proposed W-112 Project. This report documents the results of that review. In summary, no buildings exist at the Hanford Site that can be utilized for storage of solid LLMW on a cost-effective basis when compared to new construction. The nearest approach to an economically sensible conversion would involve upgrade of 100,000 ft{sup 2} of space in the 2101-M Building in the 200 East Area. Here, modified storage space is estimated to cost about $106 per ft{sup 2} while new construction will cost about $50 per ft{sup 2}. Construction costs for the waste storage portion of the W-112 Project are comparable with W-016 Project actual costs, with escalation considered. Details of the cost evaluation for this building and for other selected candidate facilities are presented in this report. All comparisons presented address the potential decontamination and decommissioning (D&D) cost avoidances realized by using existing facilities.

  20. Superhalogens as Building Blocks of Complex Hydrides for Hydrogen Storage

    CERN Document Server

    Srivastava, Ambrish Kumar

    2016-01-01

    Superhalogens are species whose electron affinity (EA) or vertical detachment energy (VDE) exceed to those of halogen. These species typically consist of a central electropositive atom with electronegative ligands. The EA or VDE of species can be further increased by using superhalogen as ligands, which are termed as hyperhalogen. Having established BH4- as a superhalogen, we have studied BH4-x(BH4)x- (x = 1 to 4) hyperhalogen anions and their Li-complexes, LiBH4-x(BH4)x using density functional theory. The VDE of these anions is larger than that of BH4-, which increases with the increase in the number of peripheral BH4 moieties (x). The hydrogen storage capacity of LiBH4-x(BH4)x complexes is higher but binding energy is smaller than that of LiBH4, a typical complex hydride. The linear correlation between dehydrogenation energy of LiBH4-x(BH4)x complexes and VDE of BH4-x(BH4)x- anions is established. These complexes are found to be thermodynamically stable against dissociation into LiBH4 and borane. This stud...

  1. Building America Top Innovations 2012: Thermal Bypass Air Barriers in the 2009 International Energy Conservation Code

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2013-01-01

    This Building America Top Innovations profile describes Building America research supporting Thermal Bypass Air Barrier requirements. Since these were adopted in the 2009 IECC, close to one million homes have been mandated to include this vitally important energy efficiency measure.

  2. Seasonal thermal energy storage program. Progress report, January 1980-December 1980

    Energy Technology Data Exchange (ETDEWEB)

    Minor, J.E.

    1981-05-01

    The objectives of the Seasonal Thermal Energy Storage (STES) Program is to demonstrate the economic storage and retrieval of energy on a seasonal basis, using heat or cold available from waste sources or other sources during a surplus period to reduce peak period demand, reduce electric utilities peaking problems, and contribute to the establishment of favorable economics for district heating and cooling systems for commercialization of the technology. Aquifers, ponds, earth, and lakes have potential for seasonal storage. The initial thrust of the STES Program is toward utilization of ground-water systems (aquifers) for thermal energy storage. Program plans for meeting these objectives, the development of demonstration programs, and progress in assessing the technical, economic, legal, and environmental impacts of thermal energy storage are described. (LCL)

  3. Experimental measurements of thermal properties for Mexican building materials to simulate thermal behavior to save energy

    Energy Technology Data Exchange (ETDEWEB)

    Chavez-Galan, Jesus; Almanza, Rafael; Rodriguez, Neftali [Universidad Nacional Autonoma de Mexico (Mexico). Inst. de Ingenieria

    2008-07-01

    One of the main factors that determine the reliability of building's thermal design is the values of thermal and heat transfer properties used during this process. In order to optimizing such thermal design process, there is little information available of the most utilized building materials in Mexico; hence, some measurements were carried out. We present thermal conductivity experimental results for: red brick, tepetate, adobe and concrete. Furthermore, experimental data of convective heat transfer coefficients are reported on: red brick, tepetate, adobe and concrete walls. Kondratyev methodology was used for thermal conductivity estimations. Kondratyev methodology is based on the cooling off of bodies in regular state analysis. Thermal conductivity values were: red brick k{sub L} = 0.906 W/mC, tepetate k{sub T} = 0.648 W/mC, adobe k{sub A} = 0.570 W/mC, and concrete k{sub C} = 1.918 W/mC. Red brick, tepetate, adobe and concrete test walls of 0.46 x 0.56 and 0.06 m thick, were manufactured, as well as a prototype of testing for mounting the walls, in order to evaluate their convective heat transfer coefficients. Measurements were carried out at the Institute of Engineering-UNAM Wind-Tunnel, for an air velocities interval of 2-10 m/s. Reported values for convective coefficients fluctuate on 16-134 W/m{sup 2}2 C, depending on material and position wall, as well as air velocity. (orig.)

  4. Aquifer thermal storage (ATES) for air-conditioning of a supermarket in Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Paksoy, H.O.; Turgut, B.; Dikici, D.; Evliya, H. [Cukurova University, Adana (Turkey). Faculty of Arts and Sciences; Gurbuz, Z. [Gurbuz Engineering Co., Adana (Turkey)

    2004-10-01

    A heating, ventilation and air-conditioning (HVAC) system with integrated aquifer thermal energy storage (ATES) was designed for a supermarket building in Mersin, a city near the Mediterranean coast in Turkey (36{sup o} 49' N and 34{sup o} 36' E). This is the first ATES application carried out in Turkey. The peak cooling and heating loads of the building are 195 and 74 kW, respectively. The general objective of the system is to use the groundwater from the aquifer to cool down the condenser of the HVAC system and at the same time storing this waste heat in the aquifer. Cooling with groundwater at around 18 {sup o}C instead of utilizing outside summer air at 30-35 {sup o}C decreases consumption of electrical energy significantly. In addition, stored heat can be recovered when it is needed in winter. The HVAC system with ATES started operation in August 2001 in cooling mode with an average coefficient of performance (COP) of 4.18, which is almost 60% higher than a conventional system. (author)

  5. Collection and dissemination of thermal energy storage system information for the pulp and paper industry

    Science.gov (United States)

    Edde, H.

    1981-01-01

    The collection and dissemination of thermal energy storage (TES) system technology for the pulp and paper industry with the intent of reducing fossil fuel usage is discussed. The study plan is described and a description presented of example TES systems.

  6. Study of an electrical heating system with ductless air supply and shape-stabilized PCM for thermal storage

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Kunping; Zhang, Yinping; Di, Hongfa [Department of Building Science, Tsinghua University, Beijing 100084 (China); Yang, Rui [Department of Chemical Engineering, Tsinghua University, Beijing 100084 (China)

    2007-07-15

    A kind of electrical floor heating system with a shape-stabilized phase change material (PCM) which has been studied at Tsinghua University in our previous studies, can provide space heating during the whole day and can be controlled conventionally. However, this is not suitable for office buildings where no space heating is needed at night. The effective control is very important for the heating system in such buildings. In this paper, we studied a kind of new electrical floor heating system with ductless air supply and shape-stabilized PCM for thermal storage in order to overcome the shortcomings of the passive under-floor electric heating system with thermal storage. In this paper, we investigated its thermal performance by experiments and simulation, calculated the effects of various factors and discussed the application feasibility in different climate regions. The results show that the total electrical energy consumption was shifted from the peak period to the off-peak period, which would provide significant economic benefits because of the different day and night electricity tariffs. The system can be designed by choosing PCM with proper melting temperature and be controlled by varying velocity of air supply in different conditions. (author)

  7. Wave propagation and thermodynamic losses in packed-bed thermal reservoirs for energy storage

    OpenAIRE

    2014-01-01

    This is the accepted manuscript for a paper published in Applied Energy Volume 130, 1 October 2014, Pages 648–657, DOI: 10.1016/j.apenergy.2014.02.071 This paper presents a numerical and theoretical analysis of thermal wave propagation in packed bed thermal reservoirs for energy storage applications. In such reservoirs, the range of temperatures encountered is usually such that the solid storage medium will exhibit significant changes in specific heat capacity. This in turn result...

  8. Performance characteristics of a thermal energy storage module - A transient PCM/forced convection conjugate analysis

    Science.gov (United States)

    Cao, Y.; Faghri, A.

    1991-01-01

    The performance of a thermal energy storage module is simulated numerically. The change of phase of the phase-change material (PCM) and the transient forced convective heat transfer for the transfer fluid with low Prandtl numbers are solved simultaneously as a conjugate problem. A parametric study and a system optimization are conducted. The numerical results show that module geometry is crucial to the design of a space-based thermal energy storage system.

  9. Reducing Display Bottle Cooler Energy Consumption Using PCM As Active Thermal Storage

    OpenAIRE

    Beek, Marcel van; de Jong, Hans

    2014-01-01

    The final results of an analytical and experimental study in reducing the energy consumption of a display bottle cooler using Phase Change Material (PCM) as an active thermal storage are presented. The objective of the study was to design and built a 350 dm3 glass door bottle cooler having an appliance energy consumption reduction of over 75% compared to state of the art bottle coolers (2010 figures). Calculation results show that active thermal storage using PCM can be effectively applied to...

  10. Applications of thermal energy storage to waste heat recovery in the food processing industry

    Science.gov (United States)

    Wojnar, F.; Lunberg, W. L.

    1980-01-01

    A study to assess the potential for waste heat recovery in the food industry and to evaluate prospective waste heat recovery system concepts employing thermal energy storage was conducted. The study found that the recovery of waste heat in canning facilities can be performed in significant quantities using systems involving thermal energy storage that are both practical and economical. A demonstration project is proposed to determine actual waste heat recovery costs and benefits and to encourage system implementation by the food industry.

  11. STP-ECRTS - THERMAL AND GAS ANALYSES FOR SLUDGE TRANSPORT AND STORAGE CONTAINER (STSC) STORAGE AT T PLANT

    Energy Technology Data Exchange (ETDEWEB)

    CROWE RD; APTHORPE R; LEE SJ; PLYS MG

    2010-04-29

    The Sludge Treatment Project (STP) is responsible for the disposition of sludge contained in the six engineered containers and Settler tank within the 105-K West (KW) Basin. The STP is retrieving and transferring sludge from the Settler tank into engineered container SCS-CON-230. Then, the STP will retrieve and transfer sludge from the six engineered containers in the KW Basin directly into a Sludge Transport and Storage Containers (STSC) contained in a Sludge Transport System (STS) cask. The STSC/STS cask will be transported to T Plant for interim storage of the STSC. The STS cask will be loaded with an empty STSC and returned to the KW Basin for loading of additional sludge for transportation and interim storage at T Plant. CH2MHILL Plateau Remediation Company (CHPRC) contracted with Fauske & Associates, LLC (FAI) to perform thermal and gas generation analyses for interim storage of STP sludge in the Sludge Transport and Storage Container (STSCs) at T Plant. The sludge types considered are settler sludge and sludge originating from the floor of the KW Basin and stored in containers 210 and 220, which are bounding compositions. The conditions specified by CHPRC for analysis are provided in Section 5. The FAI report (FAI/10-83, Thermal and Gas Analyses for a Sludge Transport and Storage Container (STSC) at T Plant) (refer to Attachment 1) documents the analyses. The process considered was passive, interim storage of sludge in various cells at T Plant. The FATE{trademark} code is used for the calculation. The results are shown in terms of the peak sludge temperature and hydrogen concentrations in the STSC and the T Plant cell. In particular, the concerns addressed were the thermal stability of the sludge and the potential for flammable gas mixtures. This work was performed with preliminary design information and a preliminary software configuration.

  12. Thermal Conductivity of LaNiAl Tritium Storage Materials

    Institute of Scientific and Technical Information of China (English)

    LIANG; Bin-bin; ZHAO; Wei-wei; LIU; Shan-shan; YANG; Hong-guang

    2015-01-01

    The heat transfer characteristic of metal hydride hydrogen storage materials is one of thebottlenecks for the large scale commercials application.In order to get the characteristics of LaNiAl hydrogen alloys,effects of temperature,hydrogen pressure,hydrogen storage capacity

  13. Experimental investigation on the thermal performance of heat storage walls coupled with active solar systems

    Science.gov (United States)

    Zhao, Chunyu; You, Shijun; Zhu, Chunying; Yu, Wei

    2016-12-01

    This paper presents an experimental investigation of the performance of a system combining a low-temperature water wall radiant heating system and phase change energy storage technology with an active solar system. This system uses a thermal storage wall that is designed with multilayer thermal storage plates. The heat storage material is expanded graphite that absorbs a mixture of capric acid and lauric acid. An experiment is performed to study the actual effect. The following are studied under winter conditions: (1) the temperature of the radiation wall surface, (2) the melting status of the thermal storage material in the internal plate, (3) the density of the heat flux, and (4) the temperature distribution of the indoor space. The results reveal that the room temperature is controlled between 16 and 20 °C, and the thermal storage wall meets the heating and temperature requirements. The following are also studied under summer conditions: (1) the internal relationship between the indoor temperature distribution and the heat transfer within the regenerative plates during the day and (2) the relationship between the outlet air temperature and inlet air temperature in the thermal storage wall in cooling mode at night. The results indicate that the indoor temperature is approximately 27 °C, which satisfies the summer air-conditioning requirements.

  14. Environmental and Economic Analysis of Thermal Active Building System

    Directory of Open Access Journals (Sweden)

    Paulo Fabiano Reis Lessa

    2016-05-01

    Full Text Available This paper is regarding one promising technological solution – which is so called Thermal Active Building Systems (TABS –for one of the most critical problems both in environmental and economic aspects, which is the raising energy consumption. Buildings are the principal application target of the solution once that population spends most part of their time inside them. Therefore, more energy is required to supply an increasingly demand in lighting, air conditioning, heating, electronic devices and so on. In this context, TABS emerge like a possible solution. To ensure the system efficiency or, in other words, prove its viability, it will be applied an environmental management tool (SWOT Analysis weighting all the pros and comparing with its drawbacks, based on previous experiences in implantation of such system, available in literature. A basic theoretical background, which is extremely important to a better comprehension of the system, covering both engineering and environmental management areas, is presented on this paper. Results shown that TABS are efficient mechanisms in the reduction of power consumption, committed with sustainable development, and which worth the investments in a Life Cycle Cost evaluation

  15. Methods to determine stratification efficiency of thermal energy storage processes–Review and theoretical comparison

    DEFF Research Database (Denmark)

    Haller, Michel; Cruickshank, Chynthia; Streicher, Wolfgang;

    2009-01-01

    This paper reviews different methods that have been proposed to characterize thermal stratification in energy storages from a theoretical point of view. Specifically, this paper focuses on the methods that can be used to determine the ability of a storage to promote and maintain stratification...

  16. Thermal-hydraulic assessment of concrete storage cubicle with horizontal 3013 canisters

    Energy Technology Data Exchange (ETDEWEB)

    HEARD, F.J.

    1999-04-08

    The FIDAP computer code was used to perform a series of analyses to assess the thermal-hydraulic performance characteristics of the concrete plutonium storage cubicles, as modified for the horizontal placement of 3013 canisters. Four separate models were developed ranging from a full height model of the storage cubicle to a very detailed standalone model of a horizontal 3013 canister.

  17. Gas storage cylinder formed from a composition containing thermally exfoliated graphite

    Science.gov (United States)

    Prud'Homme, Robert K. (Inventor); Aksay, Ilhan A. (Inventor)

    2012-01-01

    A gas storage cylinder or gas storage cylinder liner, formed from a polymer composite, containing at least one polymer and a modified graphite oxide material, which is a thermally exfoliated graphite oxide with a surface area of from about 300 m(exp 2)/g to 2600 m(exp 2)2/g.

  18. Thermal analysis of a building brick containing phase change material

    Energy Technology Data Exchange (ETDEWEB)

    Alawadhi, E.M. [Kuwait Univ., Safat (Kuwait). Dept. of Mechanical Engineering

    2008-07-01

    This paper presents the thermal analysis of a building brick containing phase change material (PCM) to be used in hot climates. The objective of using the PCM is to utilize its high latent heat of fusion to reduce the heat gain by absorbing the heat in the bricks through the melting process before it reaches the indoor space. The considered model consists of bricks with cylindrical holes filled with PCM. The problem is solved in a two-dimensional space using the finite element method. The thermal effectiveness of the proposed brick-PCM system is evaluated by comparing the heat flux at the indoor surface to a wall without the PCM during typical working hours. A paramedic study is conducted to assess the effect of different design parameters, such as the PCM's quantity, type, and location in the brick. The results indicate that the heat gain is significantly reduced when the PCM is incorporated into the brick, and increasing the quantity of the PCM has a positive effect. PCM cylinders located at the centerline of the bricks shows the best performance. (author)

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

    Directory of Open Access Journals (Sweden)

    Rogelio Peón Menéndez

    2014-10-01

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

  20. IEA SHC Task 42/ECES Annex 29 – A Simple Tool for the Economic Evaluation of Thermal Energy Storages

    DEFF Research Database (Denmark)

    Rathgeber, Christoph; Hiebler, Stefan; Lävemann, Eberhard;

    2016-01-01

    Within the framework of IEA SHC Task 42 / ECES Annex 29, a simple tool for the economic evaluation of thermal energy storages has been developed and tested on various existing storages. On that account, the storage capacity costs (costs per installed storage capacity) of thermal energy storages...... have been evaluated via a Top-down and a Bottom-up approach. The Top-down approach follows the assumption that the costs of energy supplied by the storage should not exceed the costs of energy from the market. The maximum acceptable storage capacity costs depend on the interest rate assigned......, seasonal heat storage is only economical via large sensible hot water storages. Contrary, if the annual number of storage cycles is sufficiently high, all thermal energy storage technologies can become competitive....

  1. Thermal properties and thermal reliability of eutectic mixtures of some fatty acids as latent heat storage materials

    Energy Technology Data Exchange (ETDEWEB)

    Ahmet Sarl; Hayati Sarl; Adem Onal [Gaziosmanpasa University, Tokat (Turkey). Dept. of Chemistry

    2004-02-01

    The present study deals with two subjects. The first one is to determine the thermal properties of lauric acid (LA)-stearic acid (SA), myristic acid (MA)-palmitic acid (PA) and palmitic acid (PA)-stearic acid (SA) eutectic mixtures as latent heat storage material. The properties were measured by the differential scanning calorimetry (DSC) analysis technique. The second one is to study the thermal reliability of these materials in view of the change in their melting temperatures and latent heats of fusion with respect to repeated thermal cycles. For this aim, the eutectic mixtures were subjected to 360 repeated melt/freeze cycles, and their thermal properties were measured after 0, 90,1 80 and 360 thermal cycles by the technique of DSC analysis. The DSC thermal analysis results show that the binary systems of LA-SA in the ratio of 75.5:24.5 wt.%, MA-PA in the ratio of 58:42 wt.% and PA-SA in the ratio of 64.2:35.8 wt.% form eutectic mixtures with melting temperatures of 37.0, 42.60 and 52.30{sup o}C and with latent heats of fusion of 182.7, 169.7 and 181.7 J g{sup -1}, respectively. These thermal properties make them possible for heat storage in passive solar heating applications with respect to climate conditions. The accelerated thermal cycle tests indicate that the changes in the melting temperatures and latent heats of fusion of the studied eutectic mixtures are not regular with increasing number of thermal cycles. However, these materials, latent heat energy storage materials, have good thermal reliability in terms of the change in their thermal properties with respect to thermal cycling for about a one-year utility period. (author)

  2. Performance of modified greenhouse dryer with thermal energy storage

    Directory of Open Access Journals (Sweden)

    Om Prakash

    2016-11-01

    Full Text Available In this attempt, the main goal is to do annual performance, environomical analysis, energy analysis and exergy analysis of the modified greenhouse dryer (MGD operating under active mode (AM and passive mode (PM. Thermal storage is being applied on the ground of MGD. It is applied in three different ways namely barren floor, floor covered with black PVC sheet (PVC and Black Coated. Experimental study of dryers in no-load conditions reveals that floor covered with a black PVC sheet is more conducive for drying purpose than other floors. The MGD under AM is found to be more effective as compared to PM for tomato and capsicum, which are high moisture content crops. For medium moisture content crop (potato chips, both dryers show relatively similar drying performance. Crops dried inside the greenhouse dryer are found to be more nutrient than open sun dried crops. The payback period of the modified greenhouse dryer under passive mode is found to be 1.11 years. However, for the active mode of the modified greenhouse dryer is only 1.89 years. The embodied energy of the passive mode of the dryer is a 480.277 kWh and 628.73 kWh for the active mode of the dryer. The CO2 emissions per annum for passive and active mode greenhouse dryers are found to be 13.45 kg and 17.6 kg respectively. The energy payback time, carbon mitigation and carbon credit have been calculated based type of crop dried. The range of exergy efficiency is 29%–86% in MGD under PM and 30%–78% in the MGD under AM. The variation of Heat utilization factor (HUF for MGD under PM is 0.12–0.38 and 0.26–0.53 for MGD under AM. The range of co-efficient of performances (COP for MGD under PM is 0.55–0.87 and 0.58–0.73 for MGD under AM.

  3. PCM thermal energy storage in cylindrical containers of various configurations

    Science.gov (United States)

    Mujumdar, A. S.; Ashraf, F. A.; Menon, A. S.; Weber, M. E.

    Experimental measurements are reported for the time variation of surface-averaged rate of heat storage during melting in single, thin-walled cylindrical containers of copper filled with a commercially available paraffin wax. For the wax used the enthalpy-temperature curve was obtained using a differential scanning calorimeter according to the ASTM method. Three lengths and three equivalent diameters of plain circular, plain square and internally partitioned cylinders were studied for their heat storage characteristics. The heat transfer measurements revealed the importance of natural convection during melting. The effects of cylinder geometry and temperature of the external fluid on instantaneous and integral heat storage rate were examined experimentally.

  4. Optimization of Norbornadiene Compounds for Solar Thermal Storage by First-Principles Calculations.

    Science.gov (United States)

    Kuisma, Mikael; Lundin, Angelica; Moth-Poulsen, Kasper; Hyldgaard, Per; Erhart, Paul

    2016-07-21

    Molecular photoswitches capable of storing solar energy are interesting candidates for future renewable energy applications. Here, using quantum mechanical calculations, we carry out a systematic screening of crucial optical (solar spectrum match) and thermal (storage energy density) properties of 64 such compounds based on the norbornadiene-quadricyclane system. Whereas a substantial number of these molecules reach the theoretical maximum solar power conversion efficiency, this requires a strong red-shift of the absorption spectrum, which causes undesirable absorption by the photoisomer as well as reduced thermal stability. These compounds typically also have a large molecular mass, leading to low storage densities. By contrast, single-substituted systems achieve a good compromise between efficiency and storage density, while avoiding competing absorption by the photo-isomer. This establishes guiding principles for the future development of molecular solar thermal storage systems.

  5. Analysis for Eccentric Multi Canister Overpack (MCO) Drops at the Canister Storage Building (CSB) (CSB-S-0073)

    Energy Technology Data Exchange (ETDEWEB)

    HOLLENBECK, R.G.

    2000-05-08

    The Spent Nuclear Fuel (SNF) Canister Storage Building (CSB) is the interim storage facility for the K-Basin SNF at the US. Department of Energy (DOE) Hanford Site. The SNF is packaged in multi-canister overpacks (MCOs). The MCOs are placed inside transport casks, then delivered to the service station inside the CSB. At the service station, the MCO handling machine (MHM) moves the MCO from the cask to a storage tube or one of two sample/weld stations. There are 220 standard storage tubes and six overpack storage tubes in a below grade reinforced concrete vault. Each storage tube can hold two MCOs.

  6. A nonventing cooling system for space environment extravehicular activity, using radiation and regenerable thermal storage

    Science.gov (United States)

    Bayes, Stephen A.; Trevino, Luis A.; Dinsmore, Craig E.

    1988-01-01

    This paper outlines the selection, design, and testing of a prototype nonventing regenerable astronaut cooling system for extravehicular activity space suit applications, for mission durations of four hours or greater. The selected system consists of the following key elements: a radiator assembly which serves as the exterior shell of the portable life support subsystem backpack; a layer of phase change thermal storage material, n-hexadecane paraffin, which acts as a regenerable thermal capacitor; a thermoelectric heat pump; and an automatic temperature control system. The capability for regeneration of thermal storage capacity with and without the aid of electric power is provided.

  7. Performance Assessment of Low-Temperature Thermal Storage with Electromagnetic Control

    Directory of Open Access Journals (Sweden)

    Ya-Wei Lee

    2014-08-01

    Full Text Available This study presents electromagnetic-controlled thermal storage (ECTS that can be directly implemented in strategies of low-temperature waste heat recovery for energy-consuming equipment. A magnetic nanofluid (MNF prepared from fine iron ferrite ferromagnetic particles is recommended as a latent heat medium (LHM. During electromagnetic induction, local flow fluctuations are generated and thermal convection in the MNF can be enhanced. The achieved results demonstrated that ECTS has a wide operational range and an optimum storage efficiency of 84.46%. Thus, a self-perturbation mode used to enhance thermal energy transportation can be designed for numerous waste heat management applications.

  8. Preparation and Characterization of Microencapsulated Hexadecane Used for Thermal Energy Storage

    Institute of Scientific and Technical Information of China (English)

    Guang Long ZOU; Zhi Cheng TAN; Xiao Zheng LAN; Li Xian SUN; Tao ZHANG

    2004-01-01

    Polyurea microcapsules about 2.5 μm in diameter containing phase change material for thermal energy storage application were synthesized and characterized by interfacial polycondensation method with toluene-2,4-diisocyanate and ethylenediamine as monomers in an emulsion system. Hexadecane was used as a phase change material and OP, which is nonionic surfactant, and used as an emulsifier. The chemical structure and thermal behavior of the microcapsules were investigated by FTIR and thermal analysis respectively. The results show encapsulated hexadecane has a good potential as a solar energy storage material.

  9. Experimental investigation of performances of microcapsule phase change material for thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Li, H. [Department of Material Science and Engineering, Nanjing University, Nanjing (China); Liu, X.; Wu, S. [Department of Physics, Nanjing University, Nanjing (China); Fang, G.

    2010-02-15

    Performances of microcapsule phase change material (MPCM) for thermal energy storage are investigated. The MPCM for thermal energy storage is prepared by a complex coacervation method with gelatin and acacia as wall materials and paraffin as core material in an emulsion system. A scanning electron microscope (SEM) was used to study the microstructure of the MPCM. In thermal analysis, a differential scanning calorimeter (DSC) was employed to determine the melting temperature, melting latent heat, solidification temperature, and solidification latent heat of the MPCM for thermal energy storage. The SEM micrograph indicates that the MPCM has been successfully synthesized and that the particle size of the MPCM is about 81 {mu}m. The DSC output results show that the melting temperature of the MPCM is 52.05 C, the melting latent heat is 141.03 kJ/kg, the solidification temperature is 59.68 C, and the solidification latent heat is 121.59 kJ/kg. The results prove that the MPCM for thermal energy storage has a larger phase change latent heat and suitable phase change temperature, so it can be considered as an efficient thermal energy storage material for heat utilizing systems. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  10. Numerical Study of Thermal Performance of Phase Change Material Energy Storage Floor in Solar Water Heating System

    Institute of Scientific and Technical Information of China (English)

    ZENG Ruo-lang; WANG Xin; ZHANG Yin-ping; DI Hong-fa; ZHANG Qun-li

    2009-01-01

    The conventional solar heating floor system contains a big water tank to store energy in the day time for heating at night,which takes much building space and is very heavy.In order to reduce the water tank velume even to cancel the tank,a novel structure of integrated water pipe floor heating system using shape-stabi-lized phase change materials (SSPCM) for thermal energy storage was developed.A numerical model was devel-oped to analyze the performance of SSPCM floor heating system under the intermittent heating condition,which was verified by our experimental data.The thermal performance of the heating system and the effects of various factors on it were analyzed numerically.The factors including phase transition temperature,heat of fusion,ther-real conductivity of SSPCM and thermal conductivity of the decoration material were analyzed.The results show that tm and kd are the most import influencing factors on the thermal performance of SSPCM floor heating sys-tem,since they determine the heat source temperature and thermal resistance between SSPCM plates and indoor air,respectively.Hm should be large to store enough thermal energy in the day time for nighttimes heating.The effects of KP can be ignored in this system.The SSPCM floor heating system has potential of making use of the daytime solar energy for heating at night efficiently in various climates when its structure is properly designed.

  11. Metal matrix-metal nanoparticle composites with tunable melting temperature and high thermal conductivity for phase-change thermal storage.

    Science.gov (United States)

    Liu, Minglu; Ma, Yuanyu; Wu, Hsinwei; Wang, Robert Y

    2015-02-24

    Phase-change materials (PCMs) are of broad interest for thermal storage and management applications. For energy-dense storage with fast thermal charging/discharging rates, a PCM should have a suitable melting temperature, large enthalpy of fusion, and high thermal conductivity. To simultaneously accomplish these traits, we custom design nanocomposites consisting of phase-change Bi nanoparticles embedded in an Ag matrix. We precisely control nanoparticle size, shape, and volume fraction in the composite by separating the nanoparticle synthesis and nanocomposite formation steps. We demonstrate a 50-100% thermal energy density improvement relative to common organic PCMs with equivalent volume fraction. We also tune the melting temperature from 236-252 °C by varying nanoparticle diameter from 8.1-14.9 nm. Importantly, the silver matrix successfully prevents nanoparticle coalescence, and no melting changes are observed during 100 melt-freeze cycles. The nanocomposite's Ag matrix also leads to very high thermal conductivities. For example, the thermal conductivity of a composite with a 10% volume fraction of 13 nm Bi nanoparticles is 128 ± 23 W/m-K, which is several orders of magnitude higher than typical thermal storage materials. We complement these measurements with calculations using a modified effective medium approximation for nanoscale thermal transport. These calculations predict that the thermal conductivity of composites with 13 nm Bi nanoparticles varies from 142 to 47 W/m-K as the nanoparticle volume fraction changes from 10 to 35%. Larger nanoparticle diameters and/or smaller nanoparticle volume fractions lead to larger thermal conductivities.

  12. Preheating Cold Gas Thruster Flow Through a Thermal Energy Storage Conversion System

    Science.gov (United States)

    2013-01-01

    Journal Article 3. DATES COVERED (From - To) January 2013- October 2013 4. TITLE AND SUBTITLE Preheating Cold Gas Thruster Flow Through a Thermal Energy... Gas Thruster Flow through a Thermal Energy Storage Conversion System Michael R. Reid1 United States Air Force, Colorado Springs, CO, 80840 David B...specific impulse relative to a cold gas flow. Electric propulsion systems, the primary competitor to solar thermal propulsion systems, rely on the rather

  13. Development and Demonstration of an Innovative Thermal Energy Storage System for Baseload Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Goswami, D. Yogi [Univ. of South Florida, Tampa, FL (United States)

    2012-09-04

    The objective of this project is to research and develop a thermal energy storage system (operating range 300°C - 450°C) based on encapsulated phase change materials (PCM) that can meet the utility-scale base-load concentrated solar power plant requirements at much lower system costs compared to the existing thermal energy storage (TES) concepts. The major focus of this program is to develop suitable encapsulation methods for existing low-cost phase change materials that would provide a cost effective and reliable solution for thermal energy storage to be integrated in solar thermal power plants. This project proposes a TES system concept that will allow for an increase of the capacity factor of the present CSP technologies to 75% or greater and reduce the cost to less than $20/kWht.

  14. THERMOCHEMICAL ENERGY STORAGE FOR SEASONAL BALANCE OF SURPLUS ELECTRICITY AND HEAT DEMAND IN DOMESTIC BUILDINGS

    OpenAIRE

    Schmidt, Matthias; Linder, Marc Philipp

    2016-01-01

    Thermochemical storage systems are predestined to store thermal energy for a long time since the storage principle itself is free of losses and allows for very high energy densities. Therefore we developed a new approach where electricity, p. e. from private PV-panels in the summer, is used to charge a thermochemical reaction system. The reaction product then can be stored in an inexpensive tank at room temperature. If there is heat demand during the winter part of the material can be supplie...

  15. Thermal energy storage with liquid-liquid systems

    Energy Technology Data Exchange (ETDEWEB)

    Santana, E.A.; Stiel, L.I. [Polytechnic Univ., Brooklyn, NY (United States)

    1989-03-01

    The use of liquid-liquid mixtures for heat and cool storage applications has been investigated. Suitable mixtures exhibit large changes in the heat of mixing above and below the critical solution temperature of the system. Analytical procedures have been utilized to determine potential energy storage capabilities of systems with upper or lower critical solution temperatures. It has been found that aqueous systems with lower critical solution temperatures in a suitable range can result in large increases in the effective heat capacity in the critical region. For cool storage with a system of this type, the cooling process results in a transformation from two liquid phases to a single phase. Heats of mixing have been measured with a flow calorimeter system for a number of potential mixtures, and the results are summarized.

  16. Preparation and Thermal Characterization of Nitrates/Expanded Graphite Composite Phase-Change Material for Thermal Energy Storage

    Science.gov (United States)

    Li, Y.; Li, P.; Zhu, Q. Z.; Li, Q. F.

    2016-11-01

    Molten nitrate is widely used as thermal storage medium in the solar thermal power plants for its appropriate phase-change temperature, high heat storage density and low cost, etc. But its low thermal conductivity, heat absorbing and releasing rate limited its application. Expanded graphite (EG) can compensate the low thermal conductivity of nitrate. In this study, binary nitrates at the weight ratio of 4:6 for LiNO3:KNO3 were prepared using static mixed melting method. EG with the mass fraction of 5 %, 10 %, 15 %, 20 % and 30 % was used to enhance the thermal conductivity. The compound of nitrates/EG was prepared using the ultrasonic smashing method. The thermal conductivity of binary nitrates, EG and nitrates/EG composite was measured by the transient plane heat source technique (TPS). The thermal behaviors were analyzed with a differential scanning calorimeter (DSC). Results showed that the addition of EG significantly enhanced the thermal conductivity, e.g., the thermal conductivity of 10 wt% EG composite phase-change material (PCM) is 8.5 W(m{^{-1}} K{^{-1}}) to 9.5 W(m{^{-1}}K{^{-1}}), which is about eight times larger than that of binary nitrates. To observe the combination morphology, pure EG, nitrates/EG composite PCM and binary nitrates were characterized using scanning electron microscope (SEM). The thermal reliability of the binary nitrates and the composite PCM was determined by DSC. Thermal cycling test showed that both binary nitrates and nitrates/EG composite material have good thermal reliability.

  17. Investigation of thermal effect on exterior wall surface of building material at urban city area

    OpenAIRE

    Mohd Fadhil Md Din, Hazlini Dzinun, M. Ponraj, Shreeshivadasan Chelliapan, Zainura Zainun Noor, Dilshah Remaz, Kenzo Iwao

    2012-01-01

    This paper describes the investigation of heat impact on the vertical surfaces of buildings based on their thermal behavior. The study was performed based on four building materials that is commonly used in Malaysia; brick, concrete, granite and white concrete tiles. The thermal performances on the building materials were investigated using a surface temperature sensor, data logging system and infrared thermography. Results showed that the brick had the capability to absorb and store heat gre...

  18. Thermal performance of residential buildings in Lisbon with large glazing areas

    OpenAIRE

    Tavares, Márcia; Gonçalves, Helder; Bastos, Jorge

    2008-01-01

    This work presents the results of an experimental study of residential buildings (multi-family apartments) with glazing areas greater than 75% of the total façade area, and for different solar exposures in Lisbon. These buildings were designed after the implementation of the first Portuguese Buildings Thermal Regulation and they are intrinsically related with the construction and architecture practiced in the last few years. The analysis includes the thermal behaviour of the apartments select...

  19. Rational use of energy by thermal insulation of residential buildings. Rationelle Energienutzung durch Waermeschutz von Wohngebaeuden

    Energy Technology Data Exchange (ETDEWEB)

    Feist, W. (Inst. Wohnen und Umwelt, Darmstadt (Germany))

    1992-01-01

    Processes in buildings need to be studied in detail to determine the technical potential of energy savings. Simulation models for thermal behaviour and simulation calculations prove that the technologies available today and the building input justifiable for the central-European climate will allow so-called passive-systems buildings to be built. Such a passive-systems building was built in Darmstadt Kranichstein. The heart of these passive-systems buildings is an excellent thermal insulation, its meticulous execution and the reduction of heat losses by ventilation. (BWI)

  20. Experimental and numerical modelling of thermal performance of a residential building in Belgrade

    Directory of Open Access Journals (Sweden)

    Vučićević Biljana

    2009-01-01

    Full Text Available The main objective of this paper is to evaluate simulation of thermal performance of a residential 4 floors high building placed in the suburb of Belgrade (ground and 3 upper floors with it's total surface area of 1410 m2. It's supplied with liquid petroleum gas storage tank as a fuel reservoir since there is automatic gas boiler in each apartment. Measurements have been carried out in first floor apartment (68 m2 heating area in heating season period. Measured parameters are: inside and outside air temperature and U-value of apartment envelope. Weather data is obtained by using METEONORM, the software package for climatic data calculation based on last 10 years measurements. TRNSYS 16 has been used as the simulation tool. The behavior of the building in terms of heating loads for climate on a daily and monthly basis in heating season is investigated. The calculations show possibility for saving energy by optimization inside temperature during different gas boiler working regimes.

  1. Preparation, characterization, and thermal properties of starch microencapsulated fatty acids as phase change materials thermal energy storage applications

    Science.gov (United States)

    Stable starch-oil composites can be prepared from renewable resources by excess steam jet-cooking aqueous slurries of starch and vegetable oils or other hydrophobic materials. Fatty acids such as stearic acid are promising phase change materials (PCMs) for latent heat thermal energy storage applica...

  2. An evaluation of thermal energy storage options for precooling gas turbine inlet air

    Energy Technology Data Exchange (ETDEWEB)

    Antoniak, Z.I.; Brown, D.R.; Drost, M.K.

    1992-12-01

    Several approaches have been used to reduce the temperature of gas turbine inlet air. One of the most successful uses off-peak electric power to drive vapor-compression-cycle ice makers. The ice is stored until the next time high ambient temperature is encountered, when the ice is used in a heat exchanger to cool the gas turbine inlet air. An alternative concept would use seasonal thermal energy storage to store winter chill for inlet air cooling. The objective of this study was to compare the performance and economics of seasonal thermal energy storage in aquifers with diurnal ice thermal energy storage for gas turbine inlet air cooling. The investigation consisted of developing computer codes to model the performance of a gas turbine, energy storage system, heat exchangers, and ancillary equipment. The performance models were combined with cost models to calculate unit capital costs and levelized energy costs for each concept. The levelized energy cost was calculated for three technologies in two locations (Minneapolis, Minnesota and Birmingham, Alabama). Precooling gas turbine inlet air with cold water supplied by an aquifer thermal energy storage system provided lower cost electricity than simply increasing the size of the turbine for meteorological and geological conditions existing in the Minneapolis vicinity. A 15 to 20% cost reduction resulted for both 0.05 and 0.2 annual operating factors. In contrast, ice storage precooling was found to be between 5 and 20% more expensive than larger gas turbines for the Minneapolis location. In Birmingham, aquifer thermal energy storage precooling was preferred at the higher capacity factor and ice storage precooling was the best option at the lower capacity factor. In both cases, the levelized cost was reduced by approximately 5% when compared to larger gas turbines.

  3. PCM thermal energy storage in cylindrical containers of various configurations

    Energy Technology Data Exchange (ETDEWEB)

    Mujumdar, A.S.; Ali Ashraf, F.; Menon, A.S.; Weber, M.E.

    1981-01-01

    Experimental measurements are reported for the time variation of surface-averaged rate of heat storage during melting in single, thin-walled cylindrical containers of copper filled with a commercially available paraffin wax. For the wax used the enthalpy-temperature curve was obtained using a differential scanning calorimeter according to the ASTM method. 12 refs.

  4. Photoswitchable Molecular Rings for Solar-Thermal Energy Storage.

    Science.gov (United States)

    Durgun, E; Grossman, Jeffrey C

    2013-03-21

    Solar-thermal fuels reversibly store solar energy in the chemical bonds of molecules by photoconversion, and can release this stored energy in the form of heat upon activation. Many conventional photoswichable molecules could be considered as solar thermal fuels, although they suffer from low energy density or short lifetime in the photoinduced high-energy metastable state, rendering their practical use unfeasible. We present a new approach to the design of chemistries for solar thermal fuel applications, wherein well-known photoswitchable molecules are connected by different linker agents to form molecular rings. This approach allows for a significant increase in both the amount of stored energy per molecule and the stability of the fuels. Our results suggest a range of possibilities for tuning the energy density and thermal stability as a function of the type of the photoswitchable molecule, the ring size, or the type of linkers.

  5. Numerical and experimental study on heat pump water heater with PCM for thermal storage

    Energy Technology Data Exchange (ETDEWEB)

    Long, Jian-You; Zhu, Dong-Sheng [Key Laboratory of Enhanced Heat Transfer and Energy Conservation of the Ministry of Education, Academy of Chemistry and Energy, South China University of Technology, Guangzhou, Guangdong 510640 (China)

    2008-07-01

    An air source heat pump water heater with phase change material (PCM) for thermal storage was designed to take advantage of off-peak electrical energy. The heat transfer model of PCM was based upon a pure conduction formulation. Quasi-steady state method was used to calculate the temperature distribution and phase front location of PCM during thermal storage process. Temperature and thermal resistance iteration approach has been developed for the analysis of temperature variation of heat transfer fluid (HTF) and phase front location of PCM during thermal release process. To test the physical validity of the calculational results, experimental studies about storing heat and releasing heat of PCM were carried. Comparison between the calculational results and the experimental data shows good agreement. Graphical results including system pressure and input power of heat pump, time-wise variation of stored and released thermal energy of PCM were presented and discussed. (author)

  6. Study on the Performance of a Ground Source Heat Pump System Assisted by Solar Thermal Storage

    Directory of Open Access Journals (Sweden)

    Yu Jin Nam

    2015-11-01

    Full Text Available A ground source heat pump system (GSHPS utilizes a relatively stable underground temperature to achieve energy-saving for heating and cooling in buildings. However, continuous long-term operation will reduce the soil temperature in winter, resulting in a decline in system performance. In this research, in order to improve the system performance of a GSHPS, a ground heat pump system integrated with solar thermal storage was developed. This solar-assisted ground heat pump system (SAGHPS can both maintain the balance of the soil temperature effectively and achieve higher system performance than the conventional system. In this paper, in order to examine the characteristics of the system, a dynamic simulation was conducted under various conditions. The results of our case study provide specific operation data such as heat exchange rate, heat source temperature, and heat pump COP. As a result, the heat pump COP of SAGHPS was 4.7%, 9.3% higher than that of the GSHPS.

  7. Optimal Deployment of Thermal Energy Storage under Diverse Economic and Climate Conditions

    Energy Technology Data Exchange (ETDEWEB)

    DeForest, Nicolas; Mendes, Goncalo; Stadler, Michael; Feng, Wei; Lai, Judy; Marnay, Chris

    2014-04-15

    This paper presents an investigation of the economic benefit of thermal energy storage (TES) for cooling, across a range of economic and climate conditions. Chilled water TES systems are simulated for a large office building in four distinct locations, Miami in the U.S.; Lisbon, Portugal; Shanghai, China; and Mumbai, India. Optimal system size and operating schedules are determined using the optimization model DER-CAM, such that total cost, including electricity and amortized capital costs are minimized. The economic impacts of each optimized TES system is then compared to systems sized using a simple heuristic method, which bases system size as fraction (50percent and 100percent) of total on-peak summer cooling loads. Results indicate that TES systems of all sizes can be effective in reducing annual electricity costs (5percent-15percent) and peak electricity consumption (13percent-33percent). The investigation also indentifies a number of criteria which drive TES investment, including low capital costs, electricity tariffs with high power demand charges and prolonged cooling seasons. In locations where these drivers clearly exist, the heuristically sized systems capture much of the value of optimally sized systems; between 60percent and 100percent in terms of net present value. However, in instances where these drivers are less pronounced, the heuristic tends to oversize systems, and optimization becomes crucial to ensure economically beneficial deployment of TES, increasing the net present value of heuristically sized systems by as much as 10 times in some instances.

  8. Thermal mass impact on energy performance of a low, medium and heavy mass building in Belgrade

    Directory of Open Access Journals (Sweden)

    Anđelković Bojan V.

    2012-01-01

    Full Text Available Heavy mass materials used in building structures and architecture can significantly affect building energy performance and occupant comfort. The purpose of this study was to investigate if thermal mass can improve the internal environment of a building, resulting in lower energy requirements from the mechanical systems. The study was focused on passive building energy performance and compared annual space heating and cooling energy requirements for an office building in Belgrade with several different applications of thermal mass. A three-dimensional building model was generated to represent a typical office building. Building shape, orientation, glazing to wall ratio, envelope insulation thickness, and indoor design conditions were held constant while location and thickness of building mass (concrete was varied between cases in a series of energy simulations. The results were compared and discussed in terms of the building space heating and cooling energy and demand affected by thermal mass. The simulation results indicated that with addition of thermal mass to the building envelope and structure: 100% of all simulated cases experienced reduced annual space heating energy requirements, 67% of all simulated cases experienced reduced annual space cooling energy requirements, 83% of all simulated cases experienced reduced peak space heating demand and 50% of all simulated cases experienced reduced peak space cooling demand. The study demonstrated that there exists a potential for reducing space heating and cooling energy requirements with heavy mass construction in the analyzed climate region (Belgrade, Serbia.

  9. A Statistical Analysis of the Economic Drivers of Battery Energy Storage in Commercial Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Long, Matthew; Simpkins, Travis; Cutler, Dylan; Anderson, Kate

    2016-11-21

    There is significant interest in using battery energy storage systems (BESS) to reduce peak demand charges, and therefore the life cycle cost of electricity, in commercial buildings. This paper explores the drivers of economic viability of BESS in commercial buildings through statistical analysis. A sample population of buildings was generated, a techno-economic optimization model was used to size and dispatch the BESS, and the resulting optimal BESS sizes were analyzed for relevant predictor variables. Explanatory regression analyses were used to demonstrate that peak demand charges are the most significant predictor of an economically viable battery, and that the shape of the load profile is the most significant predictor of the size of the battery.

  10. A Statistical Analysis of the Economic Drivers of Battery Energy Storage in Commercial Buildings: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Long, Matthew; Simpkins, Travis; Cutler, Dylan; Anderson, Katie

    2016-11-01

    There is significant interest in using battery energy storage systems (BESS) to reduce peak demand charges, and therefore the life cycle cost of electricity, in commercial buildings. This paper explores the drivers of economic viability of BESS in commercial buildings through statistical analysis. A sample population of buildings was generated, a techno-economic optimization model was used to size and dispatch the BESS, and the resulting optimal BESS sizes were analyzed for relevant predictor variables. Explanatory regression analyses were used to demonstrate that peak demand charges are the most significant predictor of an economically viable battery, and that the shape of the load profile is the most significant predictor of the size of the battery.

  11. Technical challenges and future direction for high-efficiency metal hydride thermal energy storage systems

    Science.gov (United States)

    Ward, Patrick A.; Corgnale, Claudio; Teprovich, Joseph A.; Motyka, Theodore; Hardy, Bruce; Sheppard, Drew; Buckley, Craig; Zidan, Ragaiy

    2016-04-01

    Recently, there has been increasing interest in thermal energy storage (TES) systems for concentrated solar power (CSP) plants, which allow for continuous operation when sunlight is unavailable. Thermochemical energy storage materials have the advantage of much higher energy densities than latent or sensible heat materials. Furthermore, thermochemical energy storage systems based on metal hydrides have been gaining great interest for having the advantage of higher energy densities, better reversibility, and high enthalpies. However, in order to achieve higher efficiencies desired of a thermal storage system by the US Department of Energy, the system is required to operate at temperatures >600 °C. Operation at temperatures >600 °C presents challenges including material selection, hydrogen embrittlement and permeation of containment vessels, appropriate selection of heat transfer fluids, and cost. Herein, the technical difficulties and proposed solutions associated with the use of metal hydrides as TES materials in CSP applications are discussed and evaluated.

  12. Summary Report for Concentrating Solar Power Thermal Storage Workshop: New Concepts and Materials for Thermal Energy Storage and Heat-Transfer Fluids, May 20, 2011

    Energy Technology Data Exchange (ETDEWEB)

    Glatzmaier, G.

    2011-08-01

    This document summarizes a workshop on thermal energy storage for concentrating solar power (CSP) that was held in Golden, Colorado, on May 20, 2011. The event was hosted by the U.S. Department of Energy (DOE), the National Renewable Energy Laboratory, and Sandia National Laboratories. The objective was to engage the university and laboratory research communities to identify and define research directions for developing new high-temperature materials and systems that advance thermal energy storage for CSP technologies. This workshop was motivated, in part, by the DOE SunShot Initiative, which sets a very aggressive cost goal for CSP technologies -- a levelized cost of energy of 6 cents per kilowatt-hour by 2020 with no incentives or credits.

  13. Simulated Aging and Characterization of Phase Change Materials for Thermal Management of Building Envelopes

    Science.gov (United States)

    2015-09-01

    Method B). West Conshohocken, PA: ASTM International. ———. 2009. Standard Method for Surface Burning Characteristics of Building Materials. ASTM E84-09...storage in buildings : A state of art. Renewable and Sustainable Energy Reviews 11(6):1146-1166 Yu, S., S. Jeong, C. Chyoung, and S. Kim. 2014. Bio-based...Simulated Aging and Characterization of Phase Change Materials for lhermal Management of Building Envelopes Elizabeth J. Gao, Jignesh Patel, Veera M. Boddu

  14. Heat transfer and thermal storage behaviour of gypsum boards incorporating micro-encapsulated PCM

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Chi-ming [Department of Civil Engineering, National Cheng-Kung University, 1, University Road, Tainan City 701 (China); Chen, R.H.; Lin, Ching-Yao [Department of Mechanical Engineering, Southern Taiwan University (China)

    2010-08-15

    In the application of energy storage and thermal environmental control, PCM (Phase Change Material) is a very promising material choice. This study incorporated mPCM (micro-encapsulated PCM) into gypsum to make mPCM gypsum board and then investigated the physical properties, heat transfer and thermal storage behaviour. The major control parameters are wall temperatures and the weight percentages of mPCM added to the gypsum boards. A melting fraction correlation, reduced from our test data and based on Stefan number (Ste), subcooling (Sb) and Fourier number, is proposed. It shows that case with a higher Ste or Sb can have a higher heat transfer through the hot wall. Thermal storage behaviour of mPCM gypsum boards is then analyzed. (author)

  15. High Temperature Phase Change Materials for Thermal Energy Storage Applications: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, J.; Glatzmaier, G. C.; Starace, A.; Turchi, C.; Ortega, J.

    2011-08-01

    To store thermal energy, sensible and latent heat storage materials are widely used. Latent heat thermal energy storage (TES) systems using phase change materials (PCM) are useful because of their ability to charge and discharge a large amount of heat from a small mass at constant temperature during a phase transformation. Molten salt PCM candidates for cascaded PCMs were evaluated for the temperatures near 320 degrees C, 350 degrees C, and 380 degrees C. These temperatures were selected to fill the 300 degrees C to 400 degrees C operating range typical for parabolic trough systems, that is, as one might employ in three-PCM cascaded thermal storage. Based on the results, the best candidate for temperatures near 320 degrees C was the molten salt KNO3-4.5wt%KCl. For the 350 degrees C and 380 degrees C temperatures, the evaluated molten salts are not good candidates because of the corrosiveness and the high vapor pressure of the chlorides.

  16. State of the art on high temperature thermal energy storage for power generation. Part 1. Concepts, materials and modellization

    Energy Technology Data Exchange (ETDEWEB)

    Gil, Antoni; Medrano, Marc; Martorell, Ingrid; Cabeza, Luisa F. [GREA Innovacio Concurrent, Universitat de Lleida, Pere de Cabrera s/n, 25001-Lleida (Spain); Lazaro, Ana; Dolado, Pablo; Zalba, Belen [Instituto de Investigacion en Ingenieria de Aragon, I3A, Grupo de Ingenieria Termica y Sistemas Energeticos (GITSE), Dpto. Ingenieria Mecanica, Area de Maquinas y Motores Termicos, Universidad de Zaragoza, Campus Politecnico Rio Ebro, Edificio ' Agustin de Betancourt' , Maria de Luna s/n, 50018 Zaragoza (Spain)

    2010-01-15

    Concentrated solar thermal power generation is becoming a very attractive renewable energy production system among all the different renewable options, as it has have a better potential for dispatchability. This dispatchability is inevitably linked with an efficient and cost-effective thermal storage system. Thus, of all components, thermal storage is a key one. However, it is also one of the less developed. Only a few plants in the world have tested high temperature thermal energy storage systems. In this paper, the different storage concepts are reviewed and classified. All materials considered in literature or plants are listed. And finally, modellization of such systems is reviewed. (author)

  17. Improvement of energy performances of existing buildings by application of solar thermal systems

    Directory of Open Access Journals (Sweden)

    Krstić-Furundžić Aleksandra

    2009-01-01

    Full Text Available Improvement of energy performances of the existing buildings in the suburban settlement Konjarnik in Belgrade, by the application of solar thermal systems is the topic presented in this paper. Hypothetical models of building improvements are created to allow the benefits of applying solar thermal collectors to residential buildings in Belgrade climate conditions to be estimated. This case study presents different design variants of solar thermal collectors integrated into a multifamily building envelope. The following aspects of solar thermal systems integration are analyzed in the paper: energy, architectural, ecological and economic. The results show that in Belgrade climatic conditions significant energy savings and reduction of CO2 emissions can be obtained with the application of solar thermal collectors.

  18. The pH-dependent thermal and storage stability of glycosylated caseinomacropeptide

    DEFF Research Database (Denmark)

    Siegert, Nadja; Tolkach, Alexander; Kulozik, Ulrich

    2012-01-01

    treatment and storage under different pH values. Process stability (preservation of native protein structure in terms of attached glycans) was analysed by quantifying the release of the terminal carbohydrate, N-acetylneuraminic acid (Neu5Ac), from gCMP. The results clearly showed that the thermal stability......, with a maximum release of 30% at pH 2. Acidic pH conditions were responsible for the hydrolysis of the glycans from the peptide backbone during heat treatment and storage....

  19. Adsorption properties of porous materials for solar thermal energy storage and heat pump applications

    OpenAIRE

    Jänchen, Jochen; Stach, Helmut

    2012-01-01

    The water adsorption properties of modified porous sorbents for solar thermal energy storage and heat transformation have been investigated by thermogravimetry (TG) differential thermogravimetry (DTG), microcalorimetry, measurements of water adsorption isotherms, and storage tests. A chabazite type SAPO, a dealuminated faujasite type zeolite, and a mesostructured aluminosilicate, have been synthesized and compared with common zeolites X, Y and silica gel. It has been found that optimized latt...

  20. Smart self-scheduling of Gencos with thermal and energy storage units under price uncertainty

    OpenAIRE

    Soroudi, Alireza

    2013-01-01

    This paper provides a self-scheduling tool for price taker Gencos. This methodology is based on Robust Optimization (RO) to deal with the uncertainties of market price values in the day-ahead electricity pool market. The Genco is assumed to be the entity who decides about the operating schedules of its thermal units and Compressed Air Energy Storage units. The benefits of Genco brought by smart grid technology and energy storage systems are investigated in this work. The applicability of the ...

  1. Advanced Thermal Storage System with Novel Molten Salt: December 8, 2011 - April 30, 2013

    Energy Technology Data Exchange (ETDEWEB)

    Jonemann, M.

    2013-05-01

    Final technical progress report of Halotechnics Subcontract No. NEU-2-11979-01. Halotechnics has demonstrated an advanced thermal energy storage system with a novel molten salt operating at 700 degrees C. The molten salt and storage system will enable the use of advanced power cycles such as supercritical steam and supercritical carbon dioxide in next generation CSP plants. The salt consists of low cost, earth abundant materials.

  2. Impact of UK Building Regulations on design and thermal performance of dwellings

    Institute of Scientific and Technical Information of China (English)

    LIM; D; 姚润明

    2009-01-01

    This paper looks at the progressive impact of UK Building Regulations (Part L) on the energy consumption of dwellings with respect to thermal performance of the building envelope. It provides an overview of building legislation,highlighting progressive improvement in building elemental U-values and compliance methods. The focus centres on Building Regulations from 1965 to 2006,at a time when energy conservation has become an integral component of building control due to environmental concerns. Simulation software is used to compare energy consumption for 5 typical UK dwelling types through a series of case studies which illustrate the rate of impact over recent years.

  3. Phase-change thermal energy storage: Final subcontract report

    Energy Technology Data Exchange (ETDEWEB)

    1989-11-01

    The research and development described in this document was conducted within the US Department of Energy's Solar Thermal Technology Program. The goal of this program is to advance the engineering and scientific understanding of solar thermal technology and to establish the technology base from which private industry can develop solar thermal power production options for introduction into the competitive energy market. Solar thermal technology concentrates the solar flux using tracking mirrors or lenses onto a receiver where the solar energy is absorbed as heat and converted into electricity or incorporated into products as process heat. The two primary solar thermal technologies, central receivers and distributed receivers, employ various point and line-focus optics to concentrate sunlight. Current central receiver systems use fields of heliostats (two-axes tracking mirrors) to focus the sun's radiant energy onto a single, tower-mounted receiver. Point focus concentrators up to 17 meters in diameter track the sun in two axes and use parabolic dish mirrors or Fresnel lenses to focus radiant energy onto a receiver. Troughs and bowls are line-focus tracking reflectors that concentrate sunlight onto receiver tubes along their focal lines. Concentrating collector modules can be used alone or in a multimodule system. The concentrated radiant energy absorbed by the solar thermal receiver is transported to the conversion process by a circulating working fluid. Receiver temperatures range from 100{degree}C in low-temperature troughs to over 1500{degree}C in dish and central receiver systems. 12 refs., 119 figs., 4 tabs.

  4. Regeneration and efficiency characterization of hybrid adsorbent for thermal energy storage of excess and solar heat

    Energy Technology Data Exchange (ETDEWEB)

    Dicaire, Daniel; Tezel, F. Handan [University of Ottawa, Department of Chemical and Biological Engineering, 161 Louis Pasteur, Colonel By Hall, A402, Ottawa, ON, K1N 6N5 (Canada)

    2011-03-15

    Adsorption Thermal Energy Storage (TES) is a promising technology for long term thermal energy storage of excess and solar heat. By using the exothermic reversible adsorption process, excess heat from an incinerator or solar heat from the summer can be stored and then released for heating during the winter. The usefulness of the storage system relies heavily on the temperature and quality of the heat available for regeneration of the adsorbent as it affects the storage efficiency, the amount of water released from the adsorbent and in turn the performance or energy density of the storage system. In this study, a lab scale high throughput open loop forced air adsorption TES has been built. A series of adsorption experiments were performed to determine the effect of adsorption flow rate and cycling on the chosen best performing adsorbent, AA13X from Rio Tinto Alcan. Regeneration characterization experiments were performed to determine the effect of flow rate, temperature and feed air relative humidity on the regeneration and performance of the system. The results were compared with another adsorbent to verify the observed trend. Finally, the efficiency of the thermal storage system was calculated. (author)

  5. 马来西亚区域供冷、冰蓄冷和热电联产在高层建筑中的应用经验%Experiences on district cooling system, ice thermal storage and cogeneration for high rise buildings in Malaysia

    Institute of Scientific and Technical Information of China (English)

    罗斯里·穆罕默德; 萨利姆·赛兰; 韩华

    2001-01-01

    马来西亚气温较高而且潮湿,所有高层建筑均需先进的空调系统维持其舒适、有益的室内环境。很多业主向区域供冷开发商订购冷水,而不是自己生产,促进了大型区域供冷系统、冰蓄冷及热电联产的发展。以实例介绍了马来西亚区域供冷、冰蓄冷及热电联产项目的发展及经验,探讨了综合区域能源(IDE)的概念,及其在大规模房产规划开发区的应用、获益和在为要求不断提高的用户提供高质、持续、有效服务方面所做的贡献。%Super high-rise buildings have emerged in Malaysia due to its rapid requirement of office space by commercial corporations. Typically, all high-rise buildings require state of the art air conditioning systems to maintain a comfort and conducive working environment in a high temperature and humidity condition in Malaysia. Most of the building owners have opted to subscribe chilled water provided by a district cooling developer, rather than producing themselves. This has also led to the development of large scale privately owned district cooling systems, ice storage and cogeneration plants in Malaysia. Describes the development and experience of various district cooling systems, ice storage and cogeneration projects in Malaysia. Also highlights the concept and application of Integrated District Energy within the planned large scale property development, benefits and its contribution towards providing a quality, uninterruptible and efficient service to the ever demanding customer.

  6. Thermal energy storage technologies for sustainability systems design, assessment and applications

    CERN Document Server

    Kalaiselvam, S

    2014-01-01

    Thermal Energy Storage Technologies for Sustainability is a broad-based overview describing the state-of-the-art in latent, sensible, and thermo-chemical energy storage systems and their applications across industries. Beginning with a discussion of the efficiency and conservation advantages of balancing energy demand with production, the book goes on to describe current state-of-the art technologies. Not stopping with description, the authors also discuss design, modeling, and simulation of representative systems, and end with several case studies of systems in use.Describes how thermal energ

  7. Legal and regulatory issues affecting the aquifer thermal energy storage concept

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, P.L.

    1980-10-01

    A number of legal and regulatory issus that potentially can affect implementation of the Aquifer Thermal Energy Storage (ATES) concept are examined. This concept involves the storage of thermal energy in an underground aquifer until a later date when it can be effectively utilized. Either heat energy or chill can be stored. Potential end uses of the energy include district space heating and cooling, industrial process applications, and use in agriculture or aquaculture. Issues are examined in four categories: regulatory requirements, property rights, potential liability, and issues related to heat or chill delivery.

  8. Review on thermal energy storage with phase change: materials, heat transfer analysis and applications

    Energy Technology Data Exchange (ETDEWEB)

    Zalba, Belen; Marin, Jose M. [Dpto. Ingenieria Mecanica, Campus Politecnico, Universidad de Zaragoza, EUITIZ ' EDIFICIO B.3' Maria de Luna 3 (Actur), 50015, Zaragoza (Spain); Cabeza, Luisa F. [Dpt.d' Informatica i Enginyeria Industrial, Escola, Universitaria Politecnica, Universitat de Lleida, CREA, Jaurne 11,69,25001, Lleida (Spain); Mehling, Harald [ZAE Bayem, Division 1: Energy Conversion and Storage, Walther-Meissner-Str. 6, 85748, Garching (Germany)

    2003-02-01

    Thermal energy storage in general, and phase change materials (PCMs) in particular, have been a main topic in research for the last 20 years, but although the information is quantitatively enormous, it is also spread widely in the literature, and difficult to find. In this work, a review has been carried out of the history of thermal energy storage with solid-liquid phase change. Three aspects have been the focus of this review: materials, heat transfer and applications. The paper contains listed over 150 materials used in research as PCMs, and about 45 commercially available PCMs. The paper lists over 230 references. (Author)

  9. Thermal energy storage. (Latest citations from the NTIS bibliographic database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    The bibliography contains citations concerning research programs, technological development, and commercial status of thermal energy storage (TES). The design, evaluation, feasibility, and risk assessment of aquifer TES systems are presented. Coverage includes phase change materials, solar energy storage, TES combined with cogeneration systems, aquifer characterization, and high temperature energy storage. Applications in residential and district heating and cooling, industrial processes, electric utilities, and aerospace energy systems are examined.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  10. Experimental Study on Melting and Solidification of Phase Change Material Thermal Storage

    Science.gov (United States)

    Ambarita, H.; Abdullah, I.; Siregar, C. A.; Siregar, R. E. T.; Ronowikarto, A. D.

    2017-03-01

    Melting and solidification process of Phase Change Materials (PCMs) are investigated experimentally. The tested PCMs are Paraffin wax and Steric acid which typically used for solar water heater. The objective is to explore the characteristics of the PCM when it is being melted and solidified. The experiments are performed in a glass box. One side of the box wall is heated while the opposite wall is kept constant and other walls are insulated. Temperature of the heated wall are kept constant at 80°C, 85°C, and 90°C, respectively. Every experiment is carried out for 600 minutes. Temperatures are recorded and the melting and solidification processes are pictured by using camera. The results show that the melting process starts from the upper part of the thermal storage. In the solidification process, it starts from the lower part of the thermal storage. As a thermal energy storage, Paraffin wax is better than Steric acid. This is because Paraffin wax can store more energy. At heat source temperature of 90°C, thermal energy stored by Paraffin wax and Stearic acid is 61.84 kJ and 57.39 kJ, respectively. Thus it is better to used Paraffin wax in the solar water heater as thermal energy storage.

  11. Enhanced thermal conductivity of form-stable phase change composite with single-walled carbon nanotubes for thermal energy storage.

    Science.gov (United States)

    Qian, Tingting; Li, Jinhong; Feng, Wuwei; Nian, Hong'en

    2017-03-16

    A striking contrast in the thermal conductivities of polyethylene glycol (PEG)/diatomite form-stable phase change composite (fs-PCC) with single-walled carbon nanotubes (SWCNs) as nano-additive has been reported in our present study. Compared to the pure PEG, the thermal conductivity of the prepared fs-PCC has increased from 0.24 W/mK to 0.87 W/Mk with a small SWCNs loading of 2 wt%. SWCNs are decorated on the inner surface of diatomite pores whilst retaining its porous structure. Compared to PEG/diatomite fs-PCC, the melting and solidification time of the PEG/diatomite/SWCNs fs-PCC are respectively decreased by 54.7% and 51.1%, and its thermal conductivity is 2.8 times higher. The composite can contain PEG as high as 60 wt% and maintain its original shape perfectly without any PEG leakage after subjected to 200 melt-freeze cycles. DSC results indicates that the melting point of the PEG/diatomite/SWCNs fs-PCC shifts to a lower temperature while the solidification point shifts to a higher temperature due to the presence of SWCNs. Importantly, the use of SWCNs is found to have clear beneficial effects for enhancing the thermal conductivity and thermal storage/release rates, without affecting thermal properties, chemical compatibility and thermal stability. The prepared PEG/diatomite/SWCNs fs-PCC exhibits excellent chemical and thermal durability and has potential application in solar thermal energy storage and solar heating.

  12. Microencapsulation of coco fatty acid mixture for thermal energy storage with phase change material

    Energy Technology Data Exchange (ETDEWEB)

    Ozonur, Y.; Mazman, M.; Paksoy, H.O.; Evilya, H. [Cukurova University, Adana (Turkey). Dept. of Chemistry

    2005-07-01

    Thermal energy storage systems provide several alternatives for efficient energy use and energy conservation. Microcapsules of natural coco fatty acid mixture were prepared to be used as phase change materials for thermal energy storage. The coacervation technique was used for the microencapsulation process. Several alternatives for the capsule wall material were tried. The microcapsules were characterized according to their geometric profiles, phase transition temperatures, mean particle sizes, chemical stabilities, and their thermal cycling. The diameters of microcapsules prepared in this study were about 1 mm. Coco fatty acid mixtures have kept their geometrical profiles even after 50 thermal cycles for melting and freezing operations in temperature range from 22 to 34{sup o}C. It was found that gelatin+gum Arabic mixture was the best wall material for microencapsulating coco fatty acid mixtures. (author)

  13. On the Behavior of Different PCMs in a Hot Water Storage Tank against Thermal Demands

    Directory of Open Access Journals (Sweden)

    Jacobo Porteiro

    2016-03-01

    Full Text Available Advantages, such as thermal storage improvement, are found when using PCMs (Phase Change Materials in storage tanks. The inclusion of three different types of materials in a 60 l test tank is studied. Two test methodologies were developed, and four tests were performed following each methodology. A thermal analysis is performed to check the thermal properties of each PCM. The distributions of the water temperatures inside the test tanks are evaluated by installing four Pt-100 sensors at different heights. A temperature recovery is observed after exposing the test tank to an energy demand. An energetic analysis that takes into account the energy due to the water temperature, the energy due to the PCM and the thermal loss to the ambient environment is also presented. The percentage of each PCM that remains in the liquid state after the energy demand is obtained.

  14. Thermal enhancement of charge and discharge cycles for adsorbed natural gas storage

    KAUST Repository

    Rahman, Kazi Afzalur

    2011-07-01

    The usage of adsorbed natural gas (ANG) storage is hindered by the thermal management during the adsorption and desorption processes. An effective thermal enhancement is thus essential for the development of the ANG technology and the motivation for this study is the investigation of a gas storage system with internal thermal control. We employed a fin-tube type heat exchanger that is placed in a pressurized cylinder. A distributed-parameter model is used for the theoretical modeling and simulations are conducted at assorted charging and discharging conditions. These studies included the transient thermal behaviours of the elements within the ANG-charged cylinder and parameters such as pressure and temperature profiles of adsorbent have been obtained during charge and discharge cycles, and results are compared with a conventional compressed methane vessel. © 2011 Elsevier Ltd. All rights reserved.

  15. The benefit of dividing an indirect thermal storage into two compartments: Discharge experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ragoonanan, Vishard; Davidson, Jane H.; Mantell, Susan C. [Department of Mechanical Engineering, 111 Church Street, S.E. Minneapolis, MN 55455 (United States); Homan, Kelly O. [Department of Mechanical and Aerospace Engineering, University of Missouri-Rolla, 1870 Miner Circle, Rolla, MO 65409 (United States)

    2006-01-15

    Experiments are presented to demonstrate the benefits of dividing an indirect thermal storage into two compartments. The transient discharge experiments were conducted in an undivided and equally divided 126l rectangular storage vessel, which has a height to depth aspect ratio of 9.3:1 and is inclined at 30{sup o} to the horizontal. A 240-tube copper heat exchanger with a total surface area of 2.38m{sup 2} was immersed in the storage fluid. For the divided storage, the heat exchanger flow path was in series through the two compartments. Water flow rate through the heat exchanger was varied from 0.05 to 0.15kg/s to demonstrate the effect of varying the number of transfer units (NTU) from 2.2 to 7 on the relative performance of undivided and divided storage vessels. Reported measurements include transient storage temperature distribution, heat exchanger outlet temperature, delivered energy, and exergy of the divided and undivided storage. The divided storage provides higher energy delivery rates and higher heat exchanger outlet temperatures during most of the discharge. The magnitude of these benefits depends on NTU and the extent of discharge. For a flow rate of 0.05kg/s, corresponding to a nominal NTU of 7, the divided storage delivers a maximum of 11% more energy than the undivided storage when 100l of hot water or 55% of the stored energy has been delivered. For a flow rate of 0.15kg/s, corresponding to a nominal NTU of 2.5, the divided storage delivers a maximum of 5% more energy at the same level of discharge. Data agree with first and second law analyses of a storage system comprised of two tanks in series. (author)

  16. Thermal energy storage system combining mass and PCM

    Energy Technology Data Exchange (ETDEWEB)

    1982-11-01

    The intent of this project was to construct several concrete blocks with PCM (Phase Change Material) encapsulated and to test these blocks as to heat transfer rate with and without a highly conductive matrix cast within the PCM core. The tests were to be conducted on commercially available PCM's being sold for solar applications. Unfortunately, one of the three PCM's was no longer produced commercially for sale and another would not crystallize as claimed by the manufacturer. This left one PCM, paraffin wax (the most critical to this work), to be tested. The testing showed that substantial improvement (18.5%) of heat conduction to the center of the paraffin core was obtainable with only a 2% loss of latent heat storage capacity. This finding may have a significant impact on the container designs for hydrocarbon heat storage system by showing that reduced surface to volume ratios can produce adequate heat transfer rates to the center of the PCM mass, without significant loss of performance.

  17. Numerical Investigation of Stratified Thermal Storage Tank Applied in Adsorption Heat Pump Cycle

    OpenAIRE

    Taheri, Hadi

    2014-01-01

    With the aid of the TES (Thermal Energy Storage) in the adsorption heat pump cycle, the COP of the system can be improved. Different geometrical variations of the TES with stratification device, have been investigated numerically. Furthermore,The effective thermal conductivity has been analyzed. The simulation results of a reference CFD model have been compared with experimental results. Additionally, the porous medium impact on the mixing process and turbulence has been studied numerically.

  18. Second test campaign of a pilot scale latent heat thermal energy storage - Durability and operational strategies

    Science.gov (United States)

    Garcia, Pierre; Rougé, Sylvie; Nivelon, Pierre

    2016-05-01

    A Phase Change Material (PCM) thermal energy storage module was tested in the framework of the Alsolen Sup project. Test results prove not only that the equivalent thermal resistance deduced from the first test campaign does not vary after several months and tens of melting and solidification cycles, but also that our modelling approach is valid both for design and non-nominal power rates, even if the model has to be improved to take into account varying water level and temperature stratification.

  19. 3D thermal climate monitoring in factory buildings

    NARCIS (Netherlands)

    Posselt, G.; Booij, P.S.; Thiede, S.; Fransman, J.E.; Driessen, B.J.F.; Herrmann, C.

    2015-01-01

    Guaranteeing defined conditions, such as the temperature levels inside the factory's building shell, is often important to produce high-quality products. Heating, ventilation and air conditioning (HVAC) equipment, as part of the technical building services, is energy intensive and accounts for a maj

  20. Design Verification Report Spent Nuclear Fuel (SNF) Project Canister Storage Building (CSB)

    Energy Technology Data Exchange (ETDEWEB)

    PICKETT, W.W.

    2000-09-22

    The Sub-project W379, ''Spent Nuclear Fuel Canister Storage Building (CSB),'' was established as part of the Spent Nuclear Fuel (SNF) Project. The primary mission of the CSB is to safely store spent nuclear fuel removed from the K Basins in dry storage until such time that it can be transferred to the national geological repository at Yucca Mountain Nevada. This sub-project was initiated in late 1994 by a series of studies and conceptual designs. These studies determined that the partially constructed storage building, originally built as part of the Hanford Waste Vitrification Plant (HWVP) Project, could be redesigned to safely store the spent nuclear fuel. The scope of the CSB facility initially included a receiving station, a hot conditioning system, a storage vault, and a Multi-Canister Overpack (MCO) Handling Machine (MHM). Because of evolution of the project technical strategy, the hot conditioning system was deleted from the scope and MCO welding and sampling stations were added in its place. This report outlines the methods, procedures, and outputs developed by Project W379 to verify that the provided Structures, Systems, and Components (SSCs): satisfy the design requirements and acceptance criteria; perform their intended function; ensure that failure modes and hazards have been addressed in the design; and ensure that the SSCs as installed will not adversely impact other SSCs. Because this sub-project is still in the construction/start-up phase, all verification activities have not yet been performed (e.g., canister cover cap and welding fixture system verification, MCO Internal Gas Sampling equipment verification, and As-built verification.). The verification activities identified in this report that still are to be performed will be added to the start-up punchlist and tracked to closure.

  1. System Configuration Management Implementation Procedure for the Canister Storage Building (CSB)

    Energy Technology Data Exchange (ETDEWEB)

    GARRISON, R.C.

    2000-11-28

    This document provides configuration management for the Distributed Control System (DCS), the Gaseous Effluent Monitoring System (GEMS-100) System, the Heating Ventilation and Air Conditioning (HVAC) Programmable Logic Controller (PLC), the Canister Receiving Crane (CRC) CRN-001 PLC, and both North and South vestibule door interlock system PLCs at the Canister Storage Building (CSB). This procedure identifies and defines software configuration items in the CSB control and monitoring systems, and defines configuration control throughout the system life cycle. Components of this control include: configuration status accounting; physical protection and control; and verification of the completeness and correctness of these items.

  2. Design and building of a new experimental setup for testing hydrogen storage materials

    Energy Technology Data Exchange (ETDEWEB)

    Andreasen, Anders

    2005-09-01

    For hydrogen to become the future energy carrier a suitable way of storing hydrogen is needed, especially if hydrogen is to be used in mobile applications such as cars. To test potential hydrogen storage materials with respect to capacity, kinetics and thermodynamics the Materials Research Department has a high pressure balance. However, the drawback of this equipment is, that in order to load samples, exposure towards air is inevitable. This has prompted the design and building of a new experimental setup with a detachable reactor allowing samples to be loaded under protective atmosphere. The purpose of this report is to serve as documentation of the new setup. (au)

  3. Thermal Storage Power Balancing with Model Predictive Control

    DEFF Research Database (Denmark)

    Halvgaard, Rasmus; Poulsen, Niels Kjølstad; Madsen, Henrik

    2013-01-01

    The method described in this paper balances power production and consumption with a large number of thermal loads. Linear controllers are used for the loads to track a temperature set point, while Model Predictive Control (MPC) and model estimation of the load behavior are used for coordination....... The total power consumption of all loads is controlled indirectly through a real-time price. The MPC incorporates forecasts of the power production and disturbances that influence the loads, e.g. time-varying weather forecasts, in order to react ahead of time. A simulation scenario demonstrates...

  4. A predictive model for smart control of a domestic heat pump and thermal storage

    NARCIS (Netherlands)

    Leeuwen, van R.P.; Gebhardt, I.; Wit, de J.B.; Smit, G.J.M.

    2016-01-01

    The purpose of this paper is to develop and validate a predictive model of a thermal storage which is charged by a heat pump and used for domestic hot water supply. The model is used for smart grid control purposes and requires measurement signals of flow and temperature at the inlet and outlet of t

  5. The impact of aquifer heterogeneity on the performance of aquifer thermal energy storage

    NARCIS (Netherlands)

    Sommer, W.T.; Valstar, J.R.; Gaans, van P.; Grotenhuis, J.T.C.; Rijnaarts, H.

    2013-01-01

    Heterogeneity in hydraulic properties of the subsurface is not accounted for in current design calculations of aquifer thermal energy storage (ATES). However, the subsurface is heterogeneous and thus affects the heat distribution around ATES wells. In this paper, the influence of heterogeneity on th

  6. Regional assessment of aquifers for thermal-energy storage. Volume 2. Regions 7 through 12

    Energy Technology Data Exchange (ETDEWEB)

    1981-06-01

    This volume contains information on the geologic and hydrologic framework, major aquifers, aquifers which are suitable and unsuitable for annual thermal energy storage (ATES) and the ATES potential of the following regions of the US: Unglaciated Central Region; Glaciated Appalachians, Unglaciated Appalachians; Coastal Plain; Hawaii; and Alaska. (LCL)

  7. Regional assessment of aquifers for thermal energy storage. Volume 1. Regions 1 through 6

    Energy Technology Data Exchange (ETDEWEB)

    1981-06-01

    This volume contains information on the geologic and hydrologic framework, major aquifers, aquifers which are suitable and unsuitable for annual thermal energy storage (ATES) and the ATES potential of the following regions of the US: the Western Mountains; Alluvial Basins; Columbia LAVA Plateau; Colorado Plateau; High Plains; and Glaciated Central Region. (LCL)

  8. Self-Protection of Electrochemical Storage Devices via a Thermal Reversible Sol-Gel Transition.

    Science.gov (United States)

    Yang, Hui; Liu, Zhiyuan; Chandran, Bevita K; Deng, Jiyang; Yu, Jiancan; Qi, Dianpeng; Li, Wenlong; Tang, Yuxin; Zhang, Chenguang; Chen, Xiaodong

    2015-10-07

    Thermal self-protected intelligent electrochemical storage devices are fabricated using a reversible sol-gel transition of the electrolyte, which can decrease the specific capacitance and increase and enable temperature-dependent charging and discharging rates in the device. This work represents proof of a simple and useful concept, which shows tremendous promise for the safe and controlled power delivery in electrochemical devices.

  9. Development of Proposed Standards for Testing Solar Collectors and Thermal Storage Devices. NBS Technical Note 899.

    Science.gov (United States)

    Hill, James E.; And Others

    A study has been made at the National Bureau of Standards of the different techniques that are or could be used for testing solar collectors and thermal storage devices that are used in solar heating and cooling systems. This report reviews the various testing methods and outlines a recommended test procedure, including apparatus and…

  10. Effect of Moisture Content on Thermal Properties of Porous Building Materials

    Science.gov (United States)

    Kočí, Václav; Vejmelková, Eva; Čáchová, Monika; Koňáková, Dana; Keppert, Martin; Maděra, Jiří; Černý, Robert

    2017-02-01

    The thermal conductivity and specific heat capacity of characteristic types of porous building materials are determined in the whole range of moisture content from dry to fully water-saturated state. A transient pulse technique is used in the experiments, in order to avoid the influence of moisture transport on measured data. The investigated specimens include cement composites, ceramics, plasters, and thermal insulation boards. The effect of moisture-induced changes in thermal conductivity and specific heat capacity on the energy performance of selected building envelopes containing the studied materials is then analyzed using computational modeling of coupled heat and moisture transport. The results show an increased moisture content as a substantial negative factor affecting both thermal properties of materials and energy balance of envelopes, which underlines the necessity to use moisture-dependent thermal parameters of building materials in energy-related calculations.

  11. Heat transfer enhancement in water when used as PCM in thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Cabeza, L.F. [Universitat de Lleida (Spain). Escola Universitaria Politecnica; Mehling, H.; Hiebler, S.; Ziegler, F. [Bavarian Center for Applied Energy Research, Garching (Germany)

    2002-07-01

    Efficient and reliable storage systems for thermal energy are an important requirement in many applications where heat demand and supply or availability do not coincide. Heat and cold stores can basically be divided in two groups. In sensible heat stores the temperature of the storage material is increased significantly. Latent heat stores, on the contrary, use a storage material that undergoes a phase change (PCM) and a small temperature rise is sufficient to store heat or cold. The major advantages of the phase change stores are their large heat storage capacity and their isothermal behavior during the charging and discharging process. However, while unloading a latent heat storage, the solid-liquid interface moves away from the heat transfer surface and the heat flux decreases due to the increasing thermal resistance of the growing layer of the molten/solidified medium. This effect can be reduced using techniques to increase heat transfer. In this paper, three methods to enhance the heat transfer in a cold storage working with water/ice as PCM are compared: addition of stainless steel pieces, copper pieces (both have been proposed before) and a new PCM-graphite composite material. The PCM-graphite composite material showed an increase in heat flux bigger than with any of the other techniques. (Author)

  12. The principle of seasonal thermal energy storage; Das Prinzip des saisonalen Thermospeichers

    Energy Technology Data Exchange (ETDEWEB)

    Katzenbach, R.; Arslan, U.; Rueckert, A. [Darmstadt Univ. (Germany). Inst. und Versuchsanstalt fuer Geotechnik

    1998-03-01

    The principle of seasonal thermal energy storage is based on the use of soil and groundwater for energy storage. Thermal energy (e.g. solar energy, waste heat from processes, or heat contained in seepage water) is fed into the foundation soil, where it is stored until required. On the other hand, cold can be stored during the winter season and used for cooling in summer. Optimisation means that heat is removed from the soil during the winter season, so that the soil will cool down. The cooled-down soil can then be used for cooling purposes in the summer season; at the same time, excess heat is fed back into the soil, so that the original temperature level for winter operation is regained. Heat is supplied and removed via heat exchangers or energy piles. The storage volume is defined as the soil volume containing heat exchangers or energy piles. The contribution discusses the theoretical fundamentals of heat transfer. (orig./AKF)

  13. Low Molecular Weight Norbornadiene Derivatives for Molecular Solar-Thermal Energy Storage.

    Science.gov (United States)

    Quant, Maria; Lennartson, Anders; Dreos, Ambra; Kuisma, Mikael; Erhart, Paul; Börjesson, Karl; Moth-Poulsen, Kasper

    2016-09-05

    Molecular solar-thermal energy storage systems are based on molecular switches that reversibly convert solar energy into chemical energy. Herein, we report the synthesis, characterization, and computational evaluation of a series of low molecular weight (193-260 g mol(-1) ) norbornadiene-quadricyclane systems. The molecules feature cyano acceptor and ethynyl-substituted aromatic donor groups, leading to a good match with solar irradiation, quantitative photo-thermal conversion between the norbornadiene and quadricyclane, as well as high energy storage densities (396-629 kJ kg(-1) ). The spectroscopic properties and energy storage capability have been further evaluated through density functional theory calculations, which indicate that the ethynyl moiety plays a critical role in obtaining the high oscillator strengths seen for these molecules.

  14. High-temperature acquifer thermal storage and underground heat storage; IEA ECES Annex 12: Hochtemperatur-Erdwaermesonden- und Aquiferwaermespeicher

    Energy Technology Data Exchange (ETDEWEB)

    Sanner, B.; Knoblich, K. [Giessen Univ. (Germany). Inst. fuer Angewandte Geowissenschaften; Koch, M.; Adinolfi, M. [Stuttgart Univ. (Germany). Inst. fuer Siedlungswasserbau, Wasserguete und Abfallwirtschaft

    1998-12-31

    Heat storage is essential for the reconciliation of heat supply and demand. The earth has already proved to be an excellent medium for storing large amounts of heat over longer periods of time, for instance during the cold and hot season. The efficiency of the storage is the better the lower storage losses are at high temperature levels. Unfortunately this can not be easily achieved. While thermal underground stores, which are widely used for cold storage, have proved to perform quite well at temperatures between 10 C - 40 C, it has been rather difficult to achieve similar results at higher temperatures up to 150 C as test and demonstration plants of the 1980s proved. This issue has again attracted so much interest that the IEA launched a project on high temperature underground storage in December 1998. (orig.) [Deutsch] Waermespeicherung ist von entscheidender Bedeutung, wenn es darum geht, ein Waermeangebot mit einer Waermenachfrage zeitlich zur Deckung zu bringen. Der Untergrund hat sich schon seit vielen Jahren als ein geeignetes Medium erwiesen, groessere Waermepumpen ueber laengere Zeitraeume wie etwa die kalten und warmen Jahreszeiten zu speichern. Die Effizienz eines solchen Speichers steigt mit der Hoehe des erreichten Temperaturniveaus und mit sinkenden Speicherverlusten, was leider eher gegenlaeufige Erscheinungen sind. Waehrend thermische Untergrundspeicher im Temperaturbereich von 10-40 C inzwischen erfolgreich demonstriert wurden und vor allem zur Kaeltespeicherung auch bereits vielfach eingesetzt werden, haben hoehere Temperaturen bis etwa 150 C in den Versuchs- und Demonstrationsanlagen der 80er Jahre vielfaeltige Probleme bereitet. Im Gefolge eines erneuten Interesses an unterirdischer thermischer Energiespeicherung wurde im Dezember 1997 ein Vorhaben des IEA Energiespeicherprogramms zu Untergrund-Waermespeichern hoeherer Temperatur eingerichtet. (orig.)

  15. Thermal Modeling of NUHOMS HSM-15 and HSM-1 Storage Modules at Calvert Cliffs Nuclear Power Station ISFSI

    Energy Technology Data Exchange (ETDEWEB)

    Suffield, Sarah R.; Fort, James A.; Adkins, Harold E.; Cuta, Judith M.; Collins, Brian A.; Siciliano, Edward R.

    2012-10-01

    As part of the Used Fuel Disposition Campaign of the Department of Energy (DOE), visual inspections and temperature measurements were performed on two storage modules in the Calvert Cliffs Nuclear Power Station’s Independent Spent Fuel Storage Installation (ISFSI). Detailed thermal models models were developed to obtain realistic temperature predictions for actual storage systems, in contrast to conservative and bounding design basis calculations.

  16. Development of a thermal storage system based on the heat of adsorption of water in hygroscopic materials

    NARCIS (Netherlands)

    Wijsman, A.J.T.M.; Oosterhaven, R.; Ouden, C. den

    1979-01-01

    A thermal storage system based on the heat of adsorption of water in hygroscopic materials has been studied as a component of a solar space heating system. The aim of this project is to decrease the storage volume in comparison with a rock-bed storage system by increasing the stored energy density.

  17. Thermal performance study and evaluation of comfort temperatures in vernacular buildings of North-East India

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Manoj Kumar; Atreya, S.K. [Instrument Design and Development Centre, Indian Institute of Technology Delhi, New Delhi 110016 (India); Mahapatra, Sadhan [Department of Energy, Tezpur University, Tezpur 784028, Assam (India)

    2010-02-15

    Solar passive techniques are being used in vernacular buildings throughout the world. Researchers have done extensive study on thermal performance of vernacular buildings in the different parts of the world. Vernacular architecture of North-Eastern India represents the principle of climate-responsive architecture, which still lacks experimental validation and quantitative analysis. Thermal comfort not only makes the occupants comfortable but also governs energy consumption in the building. Detailed field studies on thermal performances of typical traditional vernacular dwellings in different bioclimatic zones have been undertaken. This field study includes detailed survey of 150 vernacular dwellings, field tests and thermal sensation vote of 300 occupants on ASHRAE thermal sensation scale. Field test includes measurement of temperature, humidity, illumination level and building design parameters. Thermal performances of these vernacular dwellings were evaluated for winter, pre-summer, summer/monsoon and pre-winter months of the year 2008. This evaluation is based on 'adaptive approach', which is the outcome of the field studies and is now part of ASHRAE standard 55/2004 for predicting comfortable temperature of naturally ventilated buildings. This study also tried to find out the range of comfort temperature in these vernacular buildings for different season of the year. It has been found that these vernacular dwellings perform quite satisfactorily except in the winter months and the occupants feel comfortable in a wider range of temperature. (author)

  18. Thermal storage and transport technology using PCM; PCM chikunetsu netsuyuso gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Yamanishi, A.; Nakamuima, M.; Kakihara, T.; Konishi, S. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    2000-05-01

    The fluid type PCM (Phase Change Material) for thermal storage and transport systems has the advantage of saving energy for many kinds of energy systems. Emulsion type PCMs based on n-paraffins with melting points of 5 degree C and 60 degree C have been developed, which will be applied to air-cooling systems and waste energy recycling systems. Based on investigations of methods to cancel supercooling state and selection of the surfactant, PCMs resistant to damage from the heating-cooling thermal cycles have been developed. Calculations show that the power requirements of the PCM thermal transportation system are much less than those of the water system. (author)

  19. Thermal Analysis of a Thermal Energy Storage Unit to Enhance a Workshop Heating System Driven by Industrial Residual Water

    Directory of Open Access Journals (Sweden)

    Wenqiang Sun

    2017-02-01

    Full Text Available Various energy sources can be used for room heating, among which waste heat utilization has significantly improved in recent years. However, the majority of applicable waste heat resources are high-grade or stable thermal energy, while the low-grade or unstable waste heat resources, especially low-temperature industrial residual water (IRW, are insufficiently used. A thermal energy storage (TES unit with paraffin wax as a phase change material (PCM is designed to solve this problem in a pharmaceutical plant. The mathematical models are developed to simulate the heat storage and release processes of the TES unit. The crucial parameters in the recurrence formulae are determined: the phase change temperature range of the paraffin wax used is 47 to 56 °C, and the latent heat is 171.4 kJ/kg. Several thermal behaviors, such as the changes of melting radius, solidification radius, and fluid temperature, are simulated. In addition, the amount of heat transferred, the heat transfer rate, and the heat storage efficiency are discussed. It is presented that the medicine production unit could save 10.25% of energy consumption in the investigated application.

  20. Novel Molten Salts Thermal Energy Storage for Concentrating Solar Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Ramana G. [The University of Alabama

    2013-10-23

    The explicit UA program objective is to develop low melting point (LMP) molten salt thermal energy storage media with high thermal energy storage density for sensible heat storage systems. The novel Low Melting Point (LMP) molten salts are targeted to have the following characteristics: 1. Lower melting point (MP) compared to current salts (<222ºC) 2. Higher energy density compared to current salts (>300 MJ/m3) 3. Lower power generation cost compared to current salt In terms of lower power costs, the program target the DOE's Solar Energy Technologies Program year 2020 goal to create systems that have the potential to reduce the cost of Thermal Energy Storage (TES) to less than $15/kWh-th and achieve round trip efficiencies greater than 93%. The project has completed the experimental investigations to determine the thermo-physical, long term thermal stability properties of the LMP molten salts and also corrosion studies of stainless steel in the candidate LMP molten salts. Heat transfer and fluid dynamics modeling have been conducted to identify heat transfer geometry and relative costs for TES systems that would utilize the primary LMP molten salt candidates. The project also proposes heat transfer geometry with relevant modifications to suit the usage of our molten salts as thermal energy storage and heat transfer fluids. The essential properties of the down-selected novel LMP molten salts to be considered for thermal storage in solar energy applications were experimentally determined, including melting point, heat capacity, thermal stability, density, viscosity, thermal conductivity, vapor pressure, and corrosion resistance of SS 316. The thermodynamic modeling was conducted to determine potential high temperature stable molten salt mixtures that have thermal stability up to 1000 °C. The thermo-physical properties of select potential high temperature stable (HMP) molten salt mixtures were also experimentally determined. All the salt mixtures align with the

  1. Thermal insulation and retrofitting in old and new buildings; Daemmen und Sanieren in Alt- und Neubauten

    Energy Technology Data Exchange (ETDEWEB)

    Stempel, Ulrich E.

    2009-07-01

    Even if building owner, house owner, craftsman, architect or advisor: The book under consideration reports on aspects being considered in the case of modernizations or new buildings, respectively. The author gives supports and many practical descriptions for professional thermal insulations and sealing of roof, external walls and floors. The book reports on measures which supply the most savings with a minimum of costs.

  2. Ventilated buildings optimisation by using a coupled thermal-airflow simulation program

    DEFF Research Database (Denmark)

    Oropeza-Perez, Ivan; Østergaard, Poul Alberg; Remmen, Arne

    2011-01-01

    This work shows the optimization of natural ventilation within buildings at the stage of design and behaviour of the occupants. An evaluation is done by coupled multizone air modelling and thermal building simulation by using a deterministic set of input factors comprising among others climate...

  3. Microencapsulated n-octacosane as phase change material for thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Sari, Ahmet; Alkan, Cemil; Karaipekli, Ali [Department of Chemistry, Gaziosmanpasa University, 60240 Tokat (Turkey); Uzun, Orhan [Department of Physics, Gaziosmanpasa University, 60240 Tokat (Turkey)

    2009-10-15

    This study deals with preparation and characterization of polymethylmetracrylate (PMMA) microcapsules containing n-octacosane as phase change material for thermal energy storage. The surface morphology, particle size and particle size distribution (PSD) were studied by scanning electron microscopy (SEM). The chemical characterization of PMMA/octacosane microcapsules was made by FT-IR spectroscopy method. Thermal properties and thermal stability of microencapsulated octacosane were determined using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The melting and freezing temperatures and the latent heats of the microencapsulated octacosane as PCM were measured as 50.6 and 53.2 C, 86.4 and -88.5 J/g, respectively, by DSC analysis. TGA analysis indicated that the microencapsulated octacosane degrade in two steps and had good chemical stability. Thermal cycling test shows that the microcapsules have good thermal reliability with respect to the accelerated thermal cycling. Based on the results, it can be considered that the microencapsulated octacosane have good energy storage potential. (author)

  4. Building Thermal Envelope Systems and Materials (BTESM) and research utilization/technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    Burn, G. (comp.)

    1990-07-01

    The Monthly Report of the Building Thermal Envelope Systems and Materials (BTESM) Programs is a monthly update of both in-house ORNL projects and subcontract activities in the research areas of building materials, wall systems, foundations, roofs, building diagnostics, and research utilization and technology transfer. Presentations are not stand-alone paragraphs every month. Their principal values are the short-time lapse between accomplishment and reporting and their evolution over a period of several months..

  5. Occupant performance and building energy consumption with different philosophies of determining acceptable thermal conditions

    DEFF Research Database (Denmark)

    Toftum, Jørn; Andersen, Rune Vinther; Jensen, Kasper Lynge

    2009-01-01

    Based on building energy and indoor environment simulations, this study uses a recently developed method relying on Bayesian Network theory to estimate and compare the consequences for occupant performance and energy consumption of applying temperature criteria set according to the adaptive model...... of thermal comfort and the more conventional PMV model. Simulations were carried out for an example building with two configurations (with and without mechanical cooling) located in tropical, subtropical, and temperate climate regions. Even though indoor temperatures differed significantly between building...

  6. A numerical model for thermal energy storage systems utilising encapsulated phase change materials

    Science.gov (United States)

    Jacob, Rhys; Saman, Wasim; Bruno, Frank

    2016-05-01

    In an effort to reduce the cost of thermal energy storage for concentrated solar power plants, a thermocline storage concept was investigated. Two systems were investigated being a sensible-only and an encapsulated phase change system. Both systems have the potential to reduce the storage tank volume and/or reduce the cost of the filler material, thereby reducing the cost of the system when compared to current two-tank molten salt systems. The objective of the current paper is to create a numerical model capable of designing and simulating the aforementioned thermocline storage concepts in the open source programming language known as Python. The results of the current study are compared to previous numerical results and are found to be in good agreement.

  7. Detailed thermal-hydraulic computation into a containment building

    Energy Technology Data Exchange (ETDEWEB)

    Caruso. A.; Flour, I.; Simonin, O. [EDF/LNH, Chatou (France); Cherbonnel, C [EDF/SEPTEN, Villeurbanne (France)

    1995-09-01

    This paper deals with numerical predictions of the influence of water sprays upon stratifications into a containment building using a two-dimensional two-phase flow code. Basic equations and closure assumptions are briefly presented. A test case in a situation involving spray evaporation is first detailed to illustrate the validation step. Then results are presented for a compressible recirculating flow into a containment building with condensation phenomena.

  8. Radiation Heat Transfer Modeling Improved for Phase-Change, Thermal Energy Storage Systems

    Science.gov (United States)

    Kerslake, Thomas W.; Jacqmin, David A.

    1998-01-01

    Spacecraft solar dynamic power systems typically use high-temperature phase-change materials to efficiently store thermal energy for heat engine operation in orbital eclipse periods. Lithium fluoride salts are particularly well suited for this application because of their high heat of fusion, long-term stability, and appropriate melting point. Considerable attention has been focused on the development of thermal energy storage (TES) canisters that employ either pure lithium fluoride (LiF), with a melting point of 1121 K, or eutectic composition lithium-fluoride/calcium-difluoride (LiF-20CaF2), with a 1040 K melting point, as the phase-change material. Primary goals of TES canister development include maximizing the phase-change material melt fraction, minimizing the canister mass per unit of energy storage, and maximizing the phase-change material thermal charge/discharge rates within the limits posed by the container structure.

  9. Influence of void ratio on phase change of thermal energy storage for heat pipe receiver

    Directory of Open Access Journals (Sweden)

    Xiaohong Gui

    2015-01-01

    Full Text Available In this paper, influence of void ratio on phase change of thermal storage unit for heat pipe receiver under microgravity is numerically simulated. Accordingly, mathematical model is set up. A solidification-melting model upon the enthalpy-porosity method is specially provided to deal with phase changes. The liquid fraction distribution of thermal storage unit of heat pipe receiver is shown. The fluctuation of melting ratio in PCM canister is indicated. Numerical results are compared with experimental ones in Japan. The results show that void cavity prevents the process of phase change greatly. PCM melts slowly during sunlight periods and freezes slowly during eclipse periods as void ratio increases. The utility ratio of PCM during both sunlight periods and eclipse periods decreases obviously with the improvement of void ratio. The thermal resistance of void cavity is much higher than that of PCM canister wall. Void cavity prevents the heat transfer between PCM zone and canister wall.

  10. Ternary mixture of fatty acids as phase change materials for thermal energy storage applications

    Directory of Open Access Journals (Sweden)

    Karunesh Kant

    2016-11-01

    Full Text Available The present study deals with the development of ternary mixtures of fatty acids for low temperature thermal energy storage applications. The commercial grade fatty acids such as Capric Acid (CA, Lauric Acid (LA, Palmitic Acid (PA and Stearic Acid (SA, have been used to prepare stable, solid–liquid phase change material (PCM for the same. In this regard, a series of ternary mixture i.e. CA–LA–SA (CLS and CA–PA–SA (CPS have been developed with different weight percentages. Thermal characteristics of these developed ternary mixture i.e. melting temperature and latent heat of fusion have been measured by using Differential Scanning Calorimeter (DSC technique. The synthesized materials are found to have melting temperature in the range of 14–21 °C (along with adequate amount of latent heat of fusion, which may be quite useful for several low temperature thermal energy storage applications.

  11. Simulated thermal energy demand and actual energy consumption in refurbished and non-refurbished buildings

    Science.gov (United States)

    Ilie, C. A.; Visa, I.; Duta, A.

    2016-08-01

    The EU legal frame imposes the Nearly Zero Energy Buildings (nZEB) status to any new public building starting with January 1st, 2019 and for any other new building starting with 2021. Basically, nZEB represents a Low Energy Building (LEB) that covers more than half of the energy demand by using renewable energy systems installed on or close to it. Thus, two steps have to be followed in developing nZEB: (1) reaching the LEB status through state- of-the art architectural and construction solutions (for the new buildings) or through refurbishing for the already existent buildings, followed by (2) implementing renewables; in Romania, over 65% of the energy demand in a building is directly linked to heating, domestic hot water (DHW), and - in certain areas - for cooling. Thus, effort should be directed to reduce the thermal energy demand to be further covered by using clean and affordable systems: solar- thermal systems, heat pumps, biomass, etc. or their hybrid combinations. Obviously this demand is influenced by the onsite climatic profile and by the building performance. An almost worst case scenario is approached in the paper, considering a community implemented in a mountain area, with cold and long winters and mild summers (Odorheiul Secuiesc city, Harghita county, Romania). Three representative types of buildings are analysed: multi-family households (in blocks of flats), single-family houses and administrative buildings. For the first two types, old and refurbished buildings were comparatively discussed.

  12. Thermal and Energy Performance of Conditioned Building Due To Insulated Sloped Roof

    Science.gov (United States)

    Irwan, Suhandi Syiful; Ahmed, Azni Zain; Zakaria, Nor Zaini; Ibrahim, Norhati

    2010-07-01

    For low-rise buildings in equatorial region, the roof is exposed to solar radiation longer than other parts of the envelope. Roofs are to be designed to reject heat and moderate the thermal impact. These are determined by the design and construction of the roofing system. The pitch of roof and the properties of construction affect the heat gain into the attic and subsequently the indoor temperature of the living spaces underneath. This finally influences the thermal comfort conditions of naturally ventilated buildings and cooling load of conditioned buildings. This study investigated the effect of insulated sloping roof on thermal energy performance of the building. A whole-building thermal energy computer simulation tool, Integrated Environmental Solution (IES), was used for the modelling and analyses. A building model with dimension of 4.0 m × 4.0 m × 3.0 m was designed with insulated roof and conventional construction for other parts of the envelope. A 75 mm conductive insulation material with thermal conductivity (k-value) of 0.034 Wm-1K-1 was installed underneath the roof tiles. The building was modelled with roof pitch angles of 0° , 15°, 30°, 45°, 60° and simulated for the month of August in Malaysian climate conditions. The profile for attic temperature, indoor temperature and cooling load were downloaded and evaluated. The optimum roof pitch angle for best thermal performance and energy saving was identified. The results show the pitch angle of 0° is able to mitigate the thermal impact to provide the best thermal condition with optimum energy savings. The maximum temperature difference between insulated and non-insulted roof for attic (AtticA-B) and indoor condition (IndoorA-B) is +7.8 °C and 0.4 °C respectively with an average energy monthly savings of 3.9 %.

  13. Optimization for operating modes based on simulation of seasonal underground thermal energy storage

    Institute of Scientific and Technical Information of China (English)

    Jun ZHAO; Yan CHEN; Xinguo LI

    2008-01-01

    A simulation was performed, which concerned the feasibility of seasonal underground thermal energy storage (UTES) in Tianjin, China. The investigated sys-tem consisted of 8 boreholes. In summer, residual solar thermal energy was emitted into the soil surrounding the borehole heat exchangers through which the stored energy was extracted in winter with a ground coupled heat pump (GCHP) to provide a proper heating temperature. A simulation study was performed to study the influence of system operation modes on thermal recovery based on the experimental data of a GCHP system, local met-eorological conditions and soil properties in Tianjin. The results indicate a thermal recovery ratio of less than 67% and different temperature distributions under three modes. Finally, an operation mode was suggested based on both lower loss and better thermal recovery in the UTES.

  14. Design of a Protection Thermal Energy Storage Using Phase Change Material Coupled to a Solar Receiver

    Science.gov (United States)

    Verdier, D.; Falcoz, Q.; Ferrière, A.

    2014-12-01

    Thermal Energy Storage (TES) is the key for a stable electricity production in future Concentrated Solar Power (CSP) plants. This work presents a study on the thermal protection of the central receiver of CSP plant using a tower which is subject to considerable thermal stresses in case of cloudy events. The very high temperatures, 800 °C at design point, impose the use of special materials which are able to resist at high temperature and high mechanical constraints and high level of concentrated solar flux. In this paper we investigate a TES coupling a metallic matrix drilled with tubes of Phase Change Material (PCM) in order to store a large amount of thermal energy and release it in a short time. A numerical model is developed to optimize the arrangement of tubes into the TES. Then a methodology is given, based from the need in terms of thermal capacity, in order to help the choice of the geometry.

  15. Development and Performance Evaluation of High Temperature Concrete for Thermal Energy Storage for Solar Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Selvam, R. Panneer; Hale, Micah; Strasser, Matt

    2013-03-31

    Thermal energy can be stored by the mechanism of sensible or latent heat or heat from chemical reactions. Sensible heat is the means of storing energy by increasing the temperature of the solid or liquid. Since the concrete as media cost per kWhthermal is $1, this seems to be a very economical material to be used as a TES. This research is focused on extending the concrete TES system for higher temperatures (500 °C to 600 °C) and increasing the heat transfer performance using novel construction techniques. To store heat at high temperature special concretes are developed and tested for its performance. The storage capacity costs of the developed concrete is in the range of $0.91-$3.02/kWhthermal. Two different storage methods are investigated. In the first one heat is transported using molten slat through a stainless steel tube and heat is transported into concrete block through diffusion. The cost of the system is higher than the targeted DOE goal of $15/kWhthermal. The increase in cost of the system is due to stainless steel tube to transfer the heat from molten salt to the concrete blocks.The other method is a one-tank thermocline system in which both the hot and cold fluid occupy the same tank resulting in reduced storage tank volume. In this model, heated molten salt enters the top of the tank which contains a packed bed of quartzite rock and silica sand as the thermal energy storage (TES) medium. The single-tank storage system uses about half the salt that is required by the two-tank system for a required storage capacity. This amounts to a significant reduction in the cost of the storage system. The single tank alternative has also been proven to be cheaper than the option which uses large concrete modules with embedded heat exchangers. Using computer models optimum dimensions are determined to have an round trip efficiency of 84%. Additionally, the cost of the structured concrete thermocline configuration provides the TES

  16. Numerical study for enhancing the thermal conductivity of phase change material (PCM) storage using high thermal conductivity porous matrix

    Energy Technology Data Exchange (ETDEWEB)

    Mesalhy, O.; Lafdi, K.; Elgafy, A.; Bowman, K. [Dayton University Research Inst., OH (United States)

    2005-04-01

    In this paper, the melting process inside an irregular geometry filled with high thermal conductivity porous matrix saturated with phase change material PCM is investigated numerically. The numerical model is resting on solving the volume averaged conservation equations for mass, momentum and energy with phase change (melting) in the porous medium. The convection motion of the liquid phase inside the porous matrix is solved considering the Darcy, Brinkman and Forchiemer effects. A local thermal non-equilibrium assumption is considered due to the large difference in thermal properties between the solid matrix and PCM by applying a two energy equation model. The numerical code shows good agreement for pure PCM melting with another published numerical work. Through this study it is found that the presence of the porous matrix has a great effect on the heat transfer and melting rate of the PCM energy storage. Decreasing the porosity of the matrix increases the melting rate, but it also damps the convection motion. It is also found that the best technique to enhance the response of the PCM storage is to use a solid matrix with high porosity and high thermal conductivity. (author)

  17. Preparation, thermal properties and thermal reliabilities of microencapsulated n-octadecane with acrylic-based polymer shells for thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Xiaolin [Advanced Materials Institute and Clearer Production Key Laboratory, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Key Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Haidian District, Beijing 100084 (China); Song, Guolin; Chu, Xiaodong; Li, Xuezhu [Advanced Materials Institute and Clearer Production Key Laboratory, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Tang, Guoyi, E-mail: tanggy@tsinghua.edu.cn [Advanced Materials Institute and Clearer Production Key Laboratory, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Key Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Haidian District, Beijing 100084 (China)

    2013-01-10

    Highlights: Black-Right-Pointing-Pointer n-Octadecane was encapsulated by p(butyl methacrylate) (PBMA) and p(butyl acrylate). Black-Right-Pointing-Pointer Microcapsules using divinylbenzene as crosslinking agent have better quality. Black-Right-Pointing-Pointer Microcapsule with butyl methacrylate-divinylbenzene has highest latent heat. Black-Right-Pointing-Pointer Microcapsule with butyl methacrylate-divinylbenzene has greatest thermal stability. Black-Right-Pointing-Pointer Phase change temperatures and enthalpies of the microcapsules varied little after thermal cycle. - Abstract: Microencapsulation of n-octadecane with crosslinked p(butyl methacrylate) (PBMA) and p(butyl acrylate) (PBA) as shells for thermal energy storage was carried out by a suspension-like polymerization. Divinylbenzene (DVB) and pentaerythritol triacrylate (PETA) were employed as crosslinking agents. The surface morphologies of the microencapsulated phase change materials (microPCMs) were studied by scanning electron microscopy (SEM). Thermal properties, thermal reliabilities and thermal stabilities of the as-prepared microPCMs were investigated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The microPCMs prepared by using DVB exhibit greater heat capacities and higher thermal stabilities compared with those prepared by using PETA. The thermal resistant temperature of the microPCM with BMA-DVB polymer was up to 248 Degree-Sign C. The phase change temperatures and latent heats of all the as-prepared microcapsules varied little after 1000 thermal cycles.

  18. Thermal battery with CO2 compression heat pump: Techno-economic optimization of a high-efficiency Smart Grid option for buildings

    DEFF Research Database (Denmark)

    Blarke, Morten; Yazawa, Kazuaki; Shakouri, Ali

    2012-01-01

    Increasing penetration levels of wind and solar power in the energy system call for the development of Smart Grid enabling technologies. As an alternative to expensive electro-chemical and mechanical storage options, the thermal energy demand in buildings offers a cost-effective option for interm......Increasing penetration levels of wind and solar power in the energy system call for the development of Smart Grid enabling technologies. As an alternative to expensive electro-chemical and mechanical storage options, the thermal energy demand in buildings offers a cost-effective option...... for intermittency-friendly electricity consumption patterns. Combining hot and cold thermal storages with new high-pressure compressor technology that allows for flexible and simultaneous production of useful heat and cooling, the paper introduces and investigates the high-efficiency thermal battery (TB) concept....... In a proof-of-concept case study, the TB replaces an existing electric resistance heater used for hot water production and an electric compressor used for air refrigeration in a central air conditioning system. A mathematical model for least-cost unit dispatch is developed. Heat pump cycle components...

  19. The Effect Of Thermal Insulation Of An Apartment Building On The Thermo-Hydraulic Stability Of Its Heating System

    Science.gov (United States)

    Kurčová, Mária

    2015-12-01

    The contribution aims to investigate the effect of the decreased thermal losses of an apartment building due to the thermal insulation of opaque external building constructions and the replacement of transparent constructions. It emphasizes the effect of the thermal characteristics of external constructions on the functionality of the existing heating system in the building and the related requirements for the renovation of the heating system in order to ensure the hydraulic stability of the system and the thermal comfort of the inhabitants.

  20. Twenty Years On!: Updating the IEA BESTEST Building Thermal Fabric Test Cases for ASHRAE Standard 140

    Energy Technology Data Exchange (ETDEWEB)

    Judkoff, R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Neymark, J. [J. Neymark & Associates, Golden, CO (United States)

    2013-07-01

    ANSI/ASHRAE Standard 140, Standard Method of Test for the Evaluation of Building Energy Analysis Computer Programs applies the IEA BESTEST building thermal fabric test cases and example simulation results originally published in 1995. These software accuracy test cases and their example simulation results, which comprise the first test suite adapted for the initial 2001 version of Standard 140, are approaching their 20th anniversary. In response to the evolution of the state of the art in building thermal fabric modeling since the test cases and example simulation results were developed, work is commencing to update the normative test specification and the informative example results.

  1. Thermal Energy Storage for Electricity Peak-demand Mitigation: A Solution in Developing and Developed World Alike

    Energy Technology Data Exchange (ETDEWEB)

    DeForest, Nicholas; Mendes, Goncalo; Stadler, Michael; Feng, Wei; Lai, Judy; Marnay, Chris

    2013-06-02

    In much of the developed world, air-conditioning in buildings is the dominant driver of summer peak electricity demand. In the developing world a steadily increasing utilization of air-conditioning places additional strain on already-congested grids. This common thread represents a large and growing threat to the reliable delivery of electricity around the world, requiring capital-intensive expansion of capacity and draining available investment resources. Thermal energy storage (TES), in the form of ice or chilled water, may be one of the few technologies currently capable of mitigating this problem cost effectively and at scale. The installation of TES capacity allows a building to meet its on-peak air conditioning load without interruption using electricity purchased off-peak and operating with improved thermodynamic efficiency. In this way, TES has the potential to fundamentally alter consumption dynamics and reduce impacts of air conditioning. This investigation presents a simulation study of a large office building in four distinct geographical contexts: Miami, Lisbon, Shanghai, and Mumbai. The optimization tool DER-CAM (Distributed Energy Resources Customer Adoption Model) is applied to optimally size TES systems for each location. Summer load profiles are investigated to assess the effectiveness and consistency in reducing peak electricity demand. Additionally, annual energy requirements are used to determine system cost feasibility, payback periods and customer savings under local utility tariffs.

  2. Application of thermal energy storage in the cement industry. Final report, September 1977--March 1978

    Energy Technology Data Exchange (ETDEWEB)

    Jaegr, F.A.; Beshore, D.G.; Miller, F.M.; Gartner, E.M.

    1978-10-01

    In the manufacture of cement, literally trillions of Btu's are rejected to the environment each year. The purpose of this feasibility study program was to determine whether thermal energy storage could be used to conserve or allow alternative uses of this rejected energy. This study identifies and quantifies the sources of rejected energy in the cement manufacturing process, establishes use of this energy, investigates various storage system concepts, and selects energy conservation systems for further study. Thermal performance and economic analyses are performed on candidate storage systems for four typical cement plants representing various methods of manufacturing cement. Through the use of thermal energy storage in conjunction with waste heat electric power generation units, an estimated 2.4 x 10/sup 13/ Btu/year, or an equivalent of 4.0 x 10/sup 6/ barrels of oil per year, can be conserved. Attractive rates of return on investment of the proposed systems are an incentive for further development.

  3. Thermal Energy Storage using PCM for Solar Domestic Hot Water Systems: A Review

    Science.gov (United States)

    Khot, S. A.; Sane, N. K.; Gawali, B. S.

    2012-06-01

    Thermal energy storage using phase chase materials (PCM) has received considerable attention in the past two decades for time dependent energy source such as solar energy. From several experimental and theoretical analyses that have been made to assess the performance of thermal energy storage systems, it has been demonstrated that PCM-based systems are reliable and viable options. This paper covers such information on PCMs and PCM-based systems developed for the application of solar domestic hot water system. In addition, economic analysis of thermal storage system using PCM in comparison with conventional storage system helps to validate its commercial possibility. From the economic analysis, it is found that, PCM based solar domestic hot water system (SWHS) provides 23 % more cumulative and life cycle savings than conventional SWHS and will continue to perform efficiently even after 15 years due to application of non-metallic tank. Payback period of PCM-based system is also less compared to conventional system. In conclusion, PCM based solar water heating systems can meet the requirements of Indian climatic situation in a cost effective and reliable manner.

  4. The Effect of Mechanical Load on the Thermal Conductivity of Building Materials

    Directory of Open Access Journals (Sweden)

    J. Toman

    2000-01-01

    Full Text Available The effect of mechanical load on the thermal conductivity of building materials in the design of envelope parts of building structures is studied. A typical building material is chosen in the practical investigation of this effect, namely the cement mortar. It is concluded that in the range of hygroscopic moisture content, lower levels of mechanical load, typically up to 90 % of compressive strength (CS, are not dangerous from the point of view of worsening the designed thermal properties, but in the overhygroscopic region, the load as low as 57 % of CS may be dangerous. The higher levels of loading are found to be always significant because they lead to marked increase of thermal conductivity which is always a negative information for a building designer.

  5. Advanced Coupled Simulation of Borehole Thermal Energy Storage Systems and Above Ground Installations

    Science.gov (United States)

    Welsch, Bastian; Rühaak, Wolfram; Schulte, Daniel O.; Bär, Kristian; Sass, Ingo

    2016-04-01

    Seasonal thermal energy storage in borehole heat exchanger arrays is a promising technology to reduce primary energy consumption and carbon dioxide emissions. These systems usually consist of several subsystems like the heat source (e.g. solarthermics or a combined heat and power plant), the heat consumer (e.g. a heating system), diurnal storages (i.e. water tanks), the borehole thermal energy storage, additional heat sources for peak load coverage (e.g. a heat pump or a gas boiler) and the distribution network. For the design of an integrated system, numerical simulations of all subsystems are imperative. A separate simulation of the borehole energy storage is well-established but represents a simplification. In reality, the subsystems interact with each other. The fluid temperatures of the heat generation system, the heating system and the underground storage are interdependent and affect the performance of each subsystem. To take into account these interdependencies, we coupled a software for the simulation of the above ground facilities with a finite element software for the modeling of the heat flow in the subsurface and the borehole heat exchangers. This allows for a more realistic view on the entire system. Consequently, a finer adjustment of the system components and a more precise prognosis of the system's performance can be ensured.

  6. Recent patents on nano-enhanced materials for use in thermal energy storage (TES).

    Science.gov (United States)

    Cabeza, Luisa F; Ferrer, Gerard; Barreneche, Camila; Solé, Aran; Juliá, José Enrique

    2016-10-27

    Thermal energy storage (TES) systems using phase change materials (PCM) have been lately studied and are presented as one of the key solutions for the implementation of renewable energies. These systems take advantage of the latent heat of phase change of PCM during their melting/solidification processes to store or release heat depending on the needs and availability. Low thermal conductivity and latent heat are the main disadvantages of organic PCM, while corrosion, subcooling and thermal stability are the prime problems that inorganic PCM present. Nanotechnology can be used to overcome these drawbacks. Nano-enhanced PCM are obtained by the dispersion of nanoparticles in the base material and thermal properties such as thermal conductivity, viscosity and specific heat capacity, within others, can be enhanced. This paper presents a review of the patents regarding the obtaining of nano-enhanced materials for thermal energy storage (TES) in order to realize the development nanotechnologies have gained in the TES field. Patents regarding the synthesis methods to obtain nano-enhanced phase materials (NEPCM) and TES systems using NEPCM have been found and are presented in the paper. The few existing number of patents found is a clear indicator of the recent and thus low development nanotechnology has in the TES field so far. Nevertheless, the results obtained with the reviewed inventions already show the big potential that nanotechnology has in TES and denote a more than probable expansion of its use in the next years.

  7. Assessment Framework of Building Facade in Optimizing Indoor Thermal Comfort of Green Building Index (GBI) Certified Office Building

    OpenAIRE

    Abdul Tharim Asniza Hamimi; Abdul Samad Muna Hanim

    2016-01-01

    During the past decade, the construction industry has seen a new trend in the development of “green” or “sustainable” construction concept around the world with vast support from prominent organization, together with the introduction of sustainable building codes. The establishment of green building certification systems worldwide is seen as one of the most efforts in the emerging green building movement. In order to support the development of the “green” and “sustainable” concept in Malaysia...

  8. Thermal behaviours of vernacular buildings in the Yemen Arab Republic

    Energy Technology Data Exchange (ETDEWEB)

    Al-Motawakel, M.K.; Probert, S.D.; Norton, B.

    1986-01-01

    A simple steady-state mathematical model, describing the average total daily rate of heat loss through the walls, windows and flat roof of a generalised Yemeni building, has been developed. From this, a technique was evolved by which designers can predict approximately the transient rate of heat loss via traditionally employed combinations of indigenous materials, as used in the walls and roof. The predictions, expressed graphically, enable designers to select the most suitable combination of locally available, indigenous building materials, so that more energy-effective dwellings can be built.

  9. Templated assembly of photoswitches significantly increases the energy-storage capacity of solar thermal fuels.

    Science.gov (United States)

    Kucharski, Timothy J; Ferralis, Nicola; Kolpak, Alexie M; Zheng, Jennie O; Nocera, Daniel G; Grossman, Jeffrey C

    2014-05-01

    Large-scale utilization of solar-energy resources will require considerable advances in energy-storage technologies to meet ever-increasing global energy demands. Other than liquid fuels, existing energy-storage materials do not provide the requisite combination of high energy density, high stability, easy handling, transportability and low cost. New hybrid solar thermal fuels, composed of photoswitchable molecules on rigid, low-mass nanostructures, transcend the physical limitations of molecular solar thermal fuels by introducing local sterically constrained environments in which interactions between chromophores can be tuned. We demonstrate this principle of a hybrid solar thermal fuel using azobenzene-functionalized carbon nanotubes. We show that, on composite bundling, the amount of energy stored per azobenzene more than doubles from 58 to 120 kJ mol(-1), and the material also maintains robust cyclability and stability. Our results demonstrate that solar thermal fuels composed of molecule-nanostructure hybrids can exhibit significantly enhanced energy-storage capabilities through the generation of template-enforced steric strain.

  10. Thermal analysis of a storage cask for 24 spent PWR fuel assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.C.; Bang, K.S.; Seo, K.S.; Kim, H.D. [Korea Atomic Energy Research Inst., Daejeon (Korea); Choi, B.I.; Lee, H.Y.; Song, M.J. [Korea Hydro and Nuclear Power Co., Ltd., Daejeon (Korea)

    2004-07-01

    The purpose of this paper is to perform a thermal analysis of a spent fuel storage cask in order to predict the maximum concrete and fuel cladding temperatures. Thermal analyses have been carried out for a storage cask under normal and off-normal conditions. The environmental temperature is assumed to be 27 {open_square} under the normal condition. The off-normal condition has an environmental temperature of 40 {open_square}. An additional off-normal condition is considered as a partial blockage of the air inlet ducts. Four of the eight inlet ducts are assumed to be completely blocked. The storage cask is designed to store 24 PWR spent fuel assemblies with a burn-up of 55,000 MWD/MTU and a cooling time of 7 years. The decay heat load from the 24 PWR assemblies is 25.2 kW. Thermal analyses of ventilation system have been carried out for the determination of the optimum duct size and shape. The finite volume computational fluid dynamics code FLUENT was used for the thermal analysis. In the results of the analysis, the maximum temperatures of the fuel rod and concrete overpack were lower than the allowable values under the normal condition and off-normal conditions.

  11. Dynamic Modeling and Performance Analysis of Sensible Thermal Energy Storage Systems

    OpenAIRE

    Nash, Austin Lee; Jain, Neera

    2016-01-01

    In this paper we consider the problem of dynamic performance evaluation for sensible thermal energy storage (TES), with a specific focus on hot water storage tanks. We derive transient performance metrics from second law principles that can be used to guide real-time decision-making aimed toward improving demand response. We show how the transient nature of the metrics can be used not only to influence the values of control variables within the system, but also to mitigate adverse effects...

  12. Scenario Analysis of Peak Demand Savings for Commercial Buildings with Thermal Mass in California

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Rongxin; Kiliccote, Sila; Piette, Mary Ann; Parrish, Kristen

    2010-05-14

    This paper reports on the potential impact of demand response (DR) strategies in commercial buildings in California based on the Demand Response Quick Assessment Tool (DRQAT), which uses EnergyPlus simulation prototypes for office and retail buildings. The study describes the potential impact of building size, thermal mass, climate, and DR strategies on demand savings in commercial buildings. Sensitivity analyses are performed to evaluate how these factors influence the demand shift and shed during the peak period. The whole-building peak demand of a commercial building with high thermal mass in a hot climate zone can be reduced by 30percent using an optimized demand response strategy. Results are summarized for various simulation scenarios designed to help owners and managers understand the potential savings for demand response deployment. Simulated demand savings under various scenarios were compared to field-measured data in numerous climate zones, allowing calibration of the prototype models. The simulation results are compared to the peak demand data from the Commercial End-Use Survey for commercial buildings in California. On the economic side, a set of electricity rates are used to evaluate the impact of the DR strategies on economic savings for different thermal mass and climate conditions. Our comparison of recent simulation to field test results provides an understanding of the DR potential in commercial buildings.

  13. Sensitivity analysis for daily building operation from the energy and thermal comfort standpoint

    Directory of Open Access Journals (Sweden)

    Ignjatović Marko G.

    2016-01-01

    Full Text Available Improving energy performance of buildings is one of the most important tasks for reaching sustainability. Assessing building energy consumption is performed more often with specialized simulation tools. Sensitivity analysis proved to be a valuable tool for creating more reliable and realistic building energy models and better buildings. This paper briefly describes the methodology for running global sensitivity analysis and tools that can be used, and presents the results of such an analysis conducted for winter period, daily, on input variables covering a real building's operation, control and occupant related parameters that affect both thermal comfort and heating energy consumption. Two sets of inputs were created. The only difference between these sets is an addition of clothing insulation and occupant heat gain as input variables. The reference building was simulated for three distinctive winter weeks. Two additional input variables have an effect especially on thermal comfort, but they do not disturb the relative order of other influential input variables. The common influential variables for both energy consumption and thermal comfort were identified and are: air handling unit sup-ply temperature and airflow rate and control system related parameters. This can help in future research into implementing the simulation-assisted optimized operation in real buildings. [Projekat Ministarstva nauke Republike Srbije, br. TR-33051: The concept of sustainable energy supply of settlements with energy efficient buildings

  14. Thermal comfort and ventilation criteria for low energy residential buildings in building codes

    DEFF Research Database (Denmark)

    Cao, Guangyu; Kurnitski, Jarek; Awbi, Hazim;

    2012-01-01

    Indoor environmental quality and energy performance of buildings are becoming more and more important in the design and construction of low energy, passive and zero energy buildings. At the same time, improved insulation and air tightness have the potential to resulting in a deterioration of the ...

  15. Development of in-aquifer heat testing for high resolution subsurface thermal-storage capability characterisation

    Science.gov (United States)

    Seibertz, Klodwig Suibert Oskar; Chirila, Marian Andrei; Bumberger, Jan; Dietrich, Peter; Vienken, Thomas

    2016-03-01

    The ongoing transition from fossil fuels to alternative energy source provision has resulted in increased geothermal uses as well as storage of the shallow subsurface. Existing approaches for exploration of shallow subsurface geothermal energy storage often lack the ability to provide information concerning the spatial variability of thermal storage parameters. However, parameter distributions have to be known to ensure that sustainable geothermal use of the shallow subsurface can take place - especially when it is subject to intensive usage. In this paper, we test a temperature decay time approach to obtain in situ, direct, qualitative, spatial high-resolution information about the distribution of thermal storage capabilities of the shallow subsurface. To achieve this, temperature data from a high-resolution Fibre-Optic-Distributed-Temperature-Sensing device, as well as data from conventional Pt100-temperature-sensors were collected during a heat injection test. The latter test was used to measure the decay time of temperature signal dissipation of the subsurface. Signal generation was provided by in-aquifer heating with a temperature self-regulating electric heating cable. Heating was carried out for 4.5 days. After this, a cooling period of 1.5 weeks was observed. Temperature dissipation data was also compared to Direct-Push-derived high-resolution (hydro-)geological data. The results show that besides hydraulic properties also the bedding and compaction state of the sediment have an impact on the thermal storage capability of the saturated subsurface. The temperature decay time approach is therefore a reliable method for obtaining information regarding the qualitative heat storage capability of heterogeneous aquifers for the use with closed loop system geothermal storage systems. Furthermore, this approach is advantageous over other commonly used methods, e.g. soil-sampling and laboratory analysis, as even small changes in (hydro-)geological properties lead to

  16. Thermal and Electrical Cover Factors: Definition and Application for Net-Zero Energy Buildings

    OpenAIRE

    Van Roy, Juan; Salenbien, Robbe; Vanhoudt, Dirk; Desmedt, Johan; Driesen, Johan

    2013-01-01

    The presented work focuses on the introduction of thermal cover factors and the assessment of their interaction with the electrical cover factors. Cover factors are used to quantify the mismatch or non-simultaneity of local production and consumption of electricity and heat. First, the electrical cover factors are redefined to include the losses related to the storage of electricity and other inherent losses. Thereafter, similar thermal cover factors are defined. This allows the assessment of...

  17. Simulating thermal behavior of AECL's spent fuel dry storage system with CATHENA

    Energy Technology Data Exchange (ETDEWEB)

    Sabourin, G. [Atomic Energy of Canada Limited, Montreal, PQ (Canada)

    1998-07-01

    This paper documents the comparisons between CATHENA predictions and temperature measurements taken at the Gentilly-2 NPP spent fuel dry storage facility and in a mock--up of a storage basket placed inside a storage cylinder. It also presents CATHENA temperature predictions related to the storage of spent fuel in MACSTOR modules as planned for Ignalina NPP, Lithuania. CATHENA has been chosen because it can simulate many noncondensable gases including air and helium, and because of its great flexibility in the representation of the MACSTOR module geometry. The results of the simulations show good agreement with the experimental measurements. The two comparisons indicate that CATHENA can be used to simulate heat transfer from the fuel to the external air circuit of the spent fuel dry storage system. For the Ignalina MACSTOR module, containing RBMK fuel having higher heat release than typical CANDU fuel, CATHENA predicts that the maximum fuel temperature is expected to be around 240 deg C, giving an acceptable margin below the maximum allowed temperature of 300 deg C. In conclusion, this paper shows that the thermalhydraulic code CATHENA can accurately predict the thermal behavior AECL's air cooled spent fuel dry storage system. (author)

  18. Infrared Thermography Assessment of Thermal Bridges in Building Envelope: Experimental Validation in a Test Room Setup

    Directory of Open Access Journals (Sweden)

    Francesco Bianchi

    2014-10-01

    Full Text Available Thermal infrared imaging is a valuable tool to perform non-destructive qualitative tests and to investigate buildings envelope thermal-energy behavior. The assessment of envelope thermal insulation, ventilation, air leakages, and HVAC performance can be implemented through the analysis of each thermogram corresponding to an object surface temperature. Thermography also allows the identification of thermal bridges in buildings’ envelope that, together with windows and doors, constitute one of the weakest component increasing thermal losses. A quantitative methodology was proposed in previous researches by the authors in order to evaluate the effect of such weak point on the energy balance of the whole building. In the present work, in-field experimental measurements were carried out with the purpose of evaluating the energy losses through the envelope of a test room experimental field. In-situ thermal transmittance of walls, ceiling and roof were continuously monitored and each element was characterized by its own thermal insulation capability. Infrared thermography and the proposed quantitative methodology were applied to assess the energy losses due to thermal bridges. The main results show that the procedure confirms to be a reliable tool to quantify the incidence of thermal bridges in the envelope thermal losses.

  19. Thermal Performance Comparison of Glass Microsphere and Perlite Insulation Systems for Liquid Hydrogen Storage Tanks

    Science.gov (United States)

    Sass, J. P.; Fesmire, J. E.; Nagy, Z. F.; Sojourner, S. J.; Morris, D. L.; Augustynowicz, S. D.

    2008-03-01

    A technology demonstration test project was conducted by the Cryogenics Test Laboratory at the Kennedy Space Center (KSC) to provide comparative thermal performance data for glass microspheres, referred to as bubbles, and perlite insulation for liquid hydrogen tank applications. Two identical 1/15th scale versions of the 3,200,000 liter spherical liquid hydrogen tanks at Launch Complex 39 at KSC were custom designed and built to serve as test articles for this test project. Evaporative (boil-off) calorimeter test protocols, including liquid nitrogen and liquid hydrogen, were established to provide tank test conditions characteristic of the large storage tanks that support the Space Shuttle launch operations. This paper provides comparative thermal performance test results for bubbles and perlite for a wide range of conditions. Thermal performance as a function of cryogenic commodity (nitrogen and hydrogen), vacuum pressure, insulation fill level, tank liquid level, and thermal cycles will be presented.

  20. Design Verification Report Spent Nuclear Fuel (SNF) Project Canister Storage Building (CSB)

    Energy Technology Data Exchange (ETDEWEB)

    BAZINET, G.D.

    2000-11-03

    The Sub-project W379, ''Spent Nuclear Fuel Canister Storage Building (CSB),'' was established as part of the Spent Nuclear Fuel (SNF) Project. The primary mission of the CSB is to safely store spent nuclear fuel removed from the K Basins in dry storage until such time that it can be transferred to the national geological repository at Yucca Mountain Nevada. This sub-project was initiated in late 1994 by a series of studies and conceptual designs. These studies determined that the partially constructed storage building, originally built as part of the Hanford Waste Vitrification Plant (HWVP) Project, could be redesigned to safely store the spent nuclear fuel. The scope of the CSB facility initially included a receiving station, a hot conditioning system, a storage vault, and a Multi-Canister Overpack (MCO) Handling Machine (MHM). Because of evolution of the project technical strategy, the hot conditioning system was deleted from the scope and MCO welding and sampling stations were added in its place. This report outlines the methods, procedures, and outputs developed by Project W379 to verify that the provided Structures, Systems, and Components (SSCs): satisfy the design requirements and acceptance criteria; perform their intended function; ensure that failure modes and hazards have been addressed in the design; and ensure that the SSCs as installed will not adversely impact other SSCs. The original version of this document was prepared by Vista Engineering for the SNF Project. The purpose of this revision is to document completion of verification actions that were pending at the time the initial report was prepared. Verification activities for the installed and operational SSCs have been completed. Verification of future additions to the CSB related to the canister cover cap and welding fixture system and MCO Internal Gas Sampling equipment will be completed as appropriate for those components. The open items related to verification of those

  1. Changes in the color, chemical stability and antioxidant capacity of thermally treated anthocyanin aqueous solution over storage.

    Science.gov (United States)

    Sui, Xiaonan; Bary, Solène; Zhou, Weibiao

    2016-02-01

    Many anthocyanin-containing foods are thermally processed to ensure their safety, and stored for some time before being consumed. However, the combination of thermal processing and subsequent storage has a significant impact on anthocyanins. This study aimed to investigate the color, chemical stability, and antioxidant capacity of thermally treated anthocyanin aqueous solutions during storage at 4, 25, 45, and 65 °C, respectively. Anthocyanin aqueous solutions were thermally treated before storage. Results showed that the degradation rate of anthocyanins in aqueous solutions was much faster than those in real food. The color of the anthocyanin aqueous solutions changed dramatically during storage. The anthocyanin aqueous solutions stored at 4 °C showed the best chemical stability. Interestingly, the antioxidant capacity of the anthocyanin aqueous solutions stored at lower temperatures remained the same; however, the antioxidant capacity of those thermally treated at 120 or 140 °C and stored at 45 or 65 °C significantly decreased.

  2. Analysis for Eccentric Multi Canister Overpack (MCO) Drops at the Canister Storage Building (CSB) (CSB-S-0073)

    Energy Technology Data Exchange (ETDEWEB)

    TU, K.C.

    1999-10-08

    Multi-Canister Overpacks (MCOs) containing spent nuclear fuel (SNF) will be routinely handled at the Canister Storage Building (CSB) during fuel movement operations in the SNF Project. This analysis was performed to investigate the potential for damage from an eccentric accidental drop onto the standard storage tube, overpack tube, service station, or sample/weld station. Appendix D was added to the FDNW document to include the peer Review Comment Record & transmittal record.

  3. Energy Storage.

    Science.gov (United States)

    Eaton, William W.

    Described are technological considerations affecting storage of energy, particularly electrical energy. The background and present status of energy storage by batteries, water storage, compressed air storage, flywheels, magnetic storage, hydrogen storage, and thermal storage are discussed followed by a review of development trends. Included are…

  4. Molten Salt-Carbon Nanotube Thermal Energy Storage for Concentrating Solar Power Systems Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Michael Schuller; Frank Little; Darren Malik; Matt Betts; Qian Shao; Jun Luo; Wan Zhong; Sandhya Shankar; Ashwin Padmanaban

    2012-03-30

    We demonstrated that adding nanoparticles to a molten salt would increase its utility as a thermal energy storage medium for a concentrating solar power system. Specifically, we demonstrated that we could increase the specific heat of nitrate and carbonate salts containing 1% or less of alumina nanoparticles. We fabricated the composite materials using both evaporative and air drying methods. We tested several thermophysical properties of the composite materials, including the specific heat, thermal conductivity, latent heat, and melting point. We also assessed the stability of the composite material with repeated thermal cycling and the effects of adding the nanoparticles on the corrosion of stainless steel by the composite salt. Our results indicate that stable, repeatable 25-50% improvements in specific heat are possible for these materials. We found that using these composite salts as the thermal energy storage material for a concentrating solar thermal power system can reduce the levelized cost of electricity by 10-20%. We conclude that these materials are worth further development and inclusion in future concentrating solar power systems.

  5. The Evaluation of Feasibility of Thermal Energy Storage System at Riga TPP-2

    Directory of Open Access Journals (Sweden)

    Ivanova P.

    2015-12-01

    Full Text Available The installation of thermal energy storage system (TES provides the optimisation of energy source, energy security supply, power plant operation and energy production flexibility. The aim of the present research is to evaluate the feasibility of thermal energy system installation at Riga TPP–2. The six modes were investigated: four for non-heating periods and two for heating periods. Different research methods were used: data statistic processing, data analysis, analogy, forecasting, financial method and correlation and regression method. In the end, the best mode was chosen – the increase of cogeneration unit efficiency during the summer.

  6. PEB: thermal oriented architectural modeling for building energy efficiency regulations

    OpenAIRE

    Leclercq, Pierre; Juchmes, Roland; Delfosse, Vincent; Safin, Stéphane; Dawans, Arnaud; Dawans, Adrien

    2011-01-01

    As part of the overhauling of the building energy efficiency regulations (following European directive 2002/91/CE), the Wallonia and Brussels-Capital Region commissioned the LUCID to develop an optional 3D graphic encoding module to be integrated with the core energy efficiency computation engine developed by Altran Europe. Our contribution consisted mostly in analyzing the target users’ needs and representations (ergonomics, UI, interactions) and implementing a bespoke 3D CAD modeler dedicat...

  7. Thermal Storage Properties of Molten Nitrate Salt-Based Nanofluids with Graphene Nanoplatelets.

    Science.gov (United States)

    Xie, Qiangzhi; Zhu, Qunzhi; Li, Yan

    2016-12-01

    In this study, the effect of concentration of nanoparticles on the thermal storage properties of molten nitrate salt-based nanofluids with graphene nanoplatelets (GNPs) was investigated. Solar salt consisting of sodium nitrate and potassium nitrate was utilized as the base material for the nanofluids. Homogeneous dispersion of GNPs within the solar salt was observed through scanning electron microscopy analysis. For both solar salt and resultant nanofluids, differential scanning calorimetry was employed to measure the thermal storage properties, including characteristic temperatures of phase change, startup heat, and specific heat capacity (SHC). A maximum increase of 16.7 % in SHC at the liquid phase was found at an optimal concentration of 1 wt% of GNPs. At the same concentration, the onset temperature decreased by 10.4 °C, the endset temperature decreased by 4.7 °C, and the startup heat decreased by 9 %.

  8. Three-Dimensional Heat Transfer Analysis for A Thermal Energy Storage Canister

    Institute of Scientific and Technical Information of China (English)

    Hou Xinbin; Xin Yuming; Yang Chunxin; Yuan Xiugan; Dong Keyong

    2001-01-01

    High temperature latent thermal storage is one of the critical techniques for a solar dynamic power system. This paper presents results from heat transfer analysis of a phase change salt containment canister. A three dimensional analysis program is developed to model heat transfer in a PCM canister. Analysis include effects of asymmetric circumference heat flux, conduction in canister walls, liquid PCM and solid PCM, void volume change and void location, and conduction and radiation across PCM vapor void. The PCM phase change process is modeled using the enthalpy method and the simulation results are compared with those of other two dimensional investigations. It's shown that there are large difference with two-dimensional analysis, therefore the three-dimensional model is necessary for system design of high temperature latent thermal storage.

  9. Environmental assessment of the potential effects of aquifer thermal energy storage systems on microorganisms in groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Hicks, R.J.; Stewart, D.L.

    1988-03-01

    The primary objective of this study was to evaluate the potential environmental effects (both adverse and beneficials) of aquifer thermal energy storage (ATES) technology pertaining to microbial communities indigenous to subsurface environments (i.e., aquifers) and the propagation, movement, and potential release of pathogenic microorganisms (specifically, Legionella) within ATES systems. Seasonal storage of thermal energy in aquifers shows great promise to reduce peak demand; reduce electric utility load problems; contribute to establishing favorable economics for district heating and cooling systems; and reduce pollution from extraction, refining, and combustion of fossil fuels. However, concerns that the widespread implementation of this technology may have adverse effects on biological systems indigeneous to aquifers, as well as help to propagate and release pathogenic organisms that enter thee environments need to be resolved. 101 refs., 2 tabs.

  10. Thermal Storage Properties of Molten Nitrate Salt-Based Nanofluids with Graphene Nanoplatelets

    Science.gov (United States)

    Xie, Qiangzhi; Zhu, Qunzhi; Li, Yan

    2016-06-01

    In this study, the effect of concentration of nanoparticles on the thermal storage properties of molten nitrate salt-based nanofluids with graphene nanoplatelets (GNPs) was investigated. Solar salt consisting of sodium nitrate and potassium nitrate was utilized as the base material for the nanofluids. Homogeneous dispersion of GNPs within the solar salt was observed through scanning electron microscopy analysis. For both solar salt and resultant nanofluids, differential scanning calorimetry was employed to measure the thermal storage properties, including characteristic temperatures of phase change, startup heat, and specific heat capacity (SHC). A maximum increase of 16.7 % in SHC at the liquid phase was found at an optimal concentration of 1 wt% of GNPs. At the same concentration, the onset temperature decreased by 10.4 °C, the endset temperature decreased by 4.7 °C, and the startup heat decreased by 9 %.

  11. Storage and exchange thermal characteristic analysis of phase change wallboard room with different conditions

    Institute of Scientific and Technical Information of China (English)

    黄凯良; 冯国会; 陈其针; 牛润萍; 刘馨

    2009-01-01

    Based on the phase change material (PCM) thermal characteristic,some testing methods such as differential scanning calorimeter (DSC) etc were used to select the low melting mixture of capric and lauric acid as PCM of phase change wallboard (PCW). The PCW room was established,and some contrast analysis of the storage and exchange thermal characteristic of PCW room and ordinary wall room were made under different conditions. The results show that the fluctuation of indoor air temperature in PCW room is smaller than that in ordinary room obviously. The exchange energy of PCM room with outdoor is less than that of ordinary wall room. In the winter condition,PCW room utilizes valley period electricity to storage energy in the night,while releases at peak period electricity in daytime,which can divert 40% of peak load. In the summer condition,PCW room can reduce the peak cooling load by 25% compared with ordinary wall room.

  12. Improvement of a thermal energy storage using plates with paraffin-graphite composite

    Energy Technology Data Exchange (ETDEWEB)

    Marin, J.M.; Zalba, B. [Universidad da Zaragoza Edificio Betancourt, Zaragoza (Spain). Dpto. Ingenieria Mecanica; Cabeza, L.F. [Universitat de Lleida (Spain). Dpto. d' Informatica i Enginyeria Industrial; Mehling, H. [ZAE Bayern, Garching (Germany). Energy Conversion and Storage

    2005-06-01

    This work aims at designing a thermal energy storage (TES) using air as heat transfer medium, efficient mainly for free-cooling but also for other applications, improving the low heat transfer rates dues to the thermal conductivity of the materials usually employed in these systems, phase change materials (PCM). In this paper, free-cooling means the storage of cold from the night to be used during the day to cool down a room. An experimental set-up has been constructed to simulate the application. The loading and unloading processes (melting and freezing of the PCM) have two disadvantages: a relative long duration, in the range from 3 to 8 h, and a very high power consumption of the fans. Using a porous matrix of graphite where the PCM is embedded, both handicaps can be noticeably overcome. The application is studied, both experimentally and numerically. (Author)

  13. Thermal Stratification in Small Solar Domestic Storage Tanks caused by Draw-offs

    DEFF Research Database (Denmark)

    Jordan, Ulrike; Furbo, Simon

    2005-01-01

    As shown in many research studies in the past, the thermal stratification of the tank caused by draw-offs has a high impact on the performance of a Solar Domestic Hot Water (SDHW) system. Nevertheless, in most tank models for system simulations the influence of the draw-off pattern on the mixing...... behaviour is not taken into account sufficiently. Two typical Danish domestic water storage tanks, each with a volume of about 150 l, were investigated. In both tanks the inlet pipes are placed at the bottom and hot water is drawn from the upper part of tank. Above the inlet pipes, differently shaped plates...... are placed in order to reduce the mixing of the incoming cold water with the warmer storage water. To measure the thermal stratification thermocouples were placed in a vertical glass tube inside the tank. Measurements were carried out with different draw-off volumes, flow rates, and initial temperatures...

  14. Computational Design of Non-natural Sugar Alcohols to Increase Thermal Storage Density: Beyond Existing Organic Phase Change Materials.

    Science.gov (United States)

    Inagaki, Taichi; Ishida, Toyokazu

    2016-09-14

    Thermal storage, a technology that enables us to control thermal energy, makes it possible to reuse a huge amount of waste heat, and materials with the ability to treat larger thermal energy are in high demand for energy-saving societies. Sugar alcohols are now one promising candidate for phase change materials (PCMs) because of their large thermal storage density. In this study, we computationally design experimentally unknown non-natural sugar alcohols and predict their thermal storage density as a basic step toward the development of new high performance PCMs. The non-natural sugar alcohol molecules are constructed in silico in accordance with the previously suggested molecular design guidelines: linear elongation of a carbon backbone, separated distribution of OH groups, and even numbers of carbon atoms. Their crystal structures are then predicted using the random search method and first-principles calculations. Our molecular simulation results clearly demonstrate that the non-natural sugar alcohols have potential ability to have thermal storage density up to ∼450-500 kJ/kg, which is significantly larger than the maximum thermal storage density of the present known organic PCMs (∼350 kJ/kg). This computational study suggests that, even in the case of H-bonded molecular crystals where the electrostatic energy contributes mainly to thermal storage density, the molecular distortion and van der Waals energies are also important factors to increase thermal storage density. In addition, the comparison between the three eight-carbon non-natural sugar alcohol isomers indicates that the selection of preferable isomers is also essential for large thermal storage density.

  15. Thermal System Analysis and Optimization of Large-Scale Compressed Air Energy Storage (CAES

    Directory of Open Access Journals (Sweden)

    Zhongguang Fu

    2015-08-01

    Full Text Available As an important solution to issues regarding peak load and renewable energy resources on grids, large-scale compressed air energy storage (CAES power generation technology has recently become a popular research topic in the area of large-scale industrial energy storage. At present, the combination of high-expansion ratio turbines with advanced gas turbine technology is an important breakthrough in energy storage technology. In this study, a new gas turbine power generation system is coupled with current CAES technology. Moreover, a thermodynamic cycle system is optimized by calculating for the parameters of a thermodynamic system. Results show that the thermal efficiency of the new system increases by at least 5% over that of the existing system.

  16. Experimental study of compatibility of reduced metal oxides with thermal energy storage lining materials

    Science.gov (United States)

    El-Leathy, Abdelrahman; Danish, Syed Noman; Al-Ansary, Hany; Jeter, Sheldon; Al-Suhaibani, Zeyad

    2016-05-01

    Solid particles have been shown to be able to operate at temperatures higher than 1000 °C in concentrated solar power (CSP) systems with thermal energy storage (TES). Thermochemical energy storage (TCES) using metal oxides have also found to be advantageous over sensible and latent heat storage concepts. This paper investigates the compatibility of the inner lining material of a TES tank with the reduced metal oxide. Two candidate metal oxides are investigated against six candidate lining materials. XRD results for both the materials are investigated and compared before and after the reduction of metal oxide at 1000°C in the presence of lining material. It is found that the lining material rich in zirconia is suitable for such application. Silicon Carbide is also found non-reacting with one of the metal oxides so it needs to be further investigated with other candidate metal oxides.

  17. PRELIMINARY REPORT: EFFECTS OF IRRADIATION AND THERMAL EXPOSURE ON ELASTOMERIC SEALS FOR CASK TRANSPORTATION AND STORAGE

    Energy Technology Data Exchange (ETDEWEB)

    Verst, C.; Skidmore, E.; Daugherty, W.

    2014-05-30

    A testing and analysis approach to predict the sealing behavior of elastomeric seal materials in dry storage casks and evaluate their ability to maintain a seal under thermal and radiation exposure conditions of extended storage and beyond was developed, and initial tests have been conducted. The initial tests evaluate the aging response of EPDM elastomer O-ring seals. The thermal and radiation exposure conditions of the CASTOR® V/21 casks were selected for testing as this cask design is of interest due to its widespread use, and close proximity of the seals to the fuel compared to other cask designs leading to a relatively high temperature and dose under storage conditions. A novel test fixture was developed to enable compression stress relaxation measurements for the seal material at the thermal and radiation exposure conditions. A loss of compression stress of 90% is suggested as the threshold at which sealing ability of an elastomeric seal would be lost. Previous studies have shown this value to be conservative to actual leakage failure for most aging conditions. These initial results indicate that the seal would be expected to retain sealing ability throughout extended storage at the cask design conditions, though longer exposure times are needed to validate this assumption. The high constant dose rate used in the testing is not prototypic of the decreasingly low dose rate that would occur under extended storage. The primary degradation mechanism of oxidation of polymeric compounds is highly dependent on temperature and time of exposure, and with radiation expected to exacerbate the oxidation.

  18. High efficiency thermal storage system for solar plants (HELSOLAR). Final report

    Energy Technology Data Exchange (ETDEWEB)

    Villarroel, Eduardo; Fernandez-Pello, Carlos; Lenartz, Jeff; Parysek, Karen

    2013-02-27

    The project objective was to develop a high temperature Thermal Storage System (TES) based on graphite and able to provide both economical and technical advantages with respect to existing solutions contributing to increase the share of Concentrated Solar Plants (CSP). One of the main disadvantages of most of the renewable energy systems is their dependence to instantaneous irradiation and, thus, lack of predictability. CSP plants with thermal storage have proved to offer a good solution to this problem although still at an elevated price. The identification of alternative concepts able to work more efficiently would help to speed up the convergence of CSP towards grid parity. One way to reduce costs is to work in a range of temperatures higher than those allowed by the actual molten salt systems, currently the benchmark for TES in CSP. This requires the use of alternative energy storage materials such as graphite, as well as the utilization of Heat Transfer Fluids (HTF) other than molten salts or organic oils. The main technical challenges identified are derived from the high temperatures and significant high pressures, which pose risks such as potential graphite and insulation oxidation, creep, fatigue, corrosion and stress-corrosion in the pipes, leakages in the joints, high blower drivers’ electrical power consumption, thermal compatibility or relative deformations of the different materials. At the end, the main challenge of the project, is to identify a technical solution able to overcome all these problems but still at a competitive cost when compared to already existing thermal storage solutions. Special attention is given to all these issues during this project.

  19. MSWI bottom ash for thermal energy storage: an innovative and sustainable approach for its reutilization

    OpenAIRE

    Valle-Zermeño, Ricardo del; Barreneche Güerisoli, Camila; Cabeza, Luisa F.; Formosa, Joan; Fernández, Ana Inés; Chimenos, J. M.

    2016-01-01

    The management of Municipal Solid Waste (MSW) is a very important issue that must be dealt by the perspective of the 3 Rs (Reuse, reduce, recycle. MSW incineration bottom ash (BA) accounts for 85–95% of the total solids that remained after incineration. Finding suitable alternatives for its revalorization is very attractive, especially in terms of environmental sustainability. Thermal energy storage (TES) is a complementary technology of renewable energy. The aim of this study is to evaluate ...

  20. Fault detection thermal storage system by expert system using fuzzy abduction

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Koichi [Yamatake-Honeywell Co., Ltd, Yokohama (Japan). Advanced Technology Center; Kamimura, Kazuyuki [Yamatake-Honeywell Co., Ltd., Tokyo (Japan). Building Systems Div.

    1996-12-31

    Fuzzy abduction is a procedure for deriving fuzzy sets of hypotheses which explain a given fuzzy set of events using a set of rules with a truth value. The derived fuzzy sets of hypotheses are called fuzzy explanations. This presentation starts with discussion about diagnosis using conventional expert systems and that using fuzzy relational equations. Then, it proposes a new approach using a fuzzy abduction, and applies the technique to fault detection of a thermal storage system. (orig.)

  1. Transformation, Conversion, Storage, Transportation of thermal energy by thermochemical processes and thermo-hydraulic processes

    OpenAIRE

    Stitou, Driss

    2013-01-01

    The research presented aims to meet the major challenges of sustainable management and rational use of energy (transport and storage of heat energy), to develop thermodynamic analysis tools and propose appropriate solutions for minimizing environmental impacts resulting from the transformation or conversion of thermal energy. The different developed themes are based on three axes. The first part concerns the development of thermodynamic analysis tools for the assessment, design and optimizati...

  2. Canister storage building (CSB) safety analysis report phase 3: Safety analysis documentation supporting CSB construction

    Energy Technology Data Exchange (ETDEWEB)

    Garvin, L.J.

    1997-04-28

    The Canister Storage Building (CSB) will be constructed in the 200 East Area of the U.S. Department of Energy (DOE) Hanford Site. The CSB will be used to stage and store spent nuclear fuel (SNF) removed from the Hanford Site K Basins. The objective of this chapter is to describe the characteristics of the site on which the CSB will be located. This description will support the hazard analysis and accident analyses in Chapter 3.0. The purpose of this report is to provide an evaluation of the CSB design criteria, the design's compliance with the applicable criteria, and the basis for authorization to proceed with construction of the CSB.

  3. New materials for thermal energy storage in concentrated solar power plants

    Science.gov (United States)

    Guerreiro, Luis; Collares-Pereira, Manuel

    2016-05-01

    Solar Thermal Electricity (STE) is an important alternative to PV electricity production, not only because it is getting more cost competitive with the continuous growth in installed capacity, engineering and associated innovations, but also, because of its unique dispatch ability advantage as a result of the already well established 2-tank energy storage using molten salts (MS). In recent years, research has been performed, on direct MS systems, to which features like modularity and combinations with other (solid) thermal storage materials are considered with the goal of achieving lower investment cost. Several alternative materials and systems have been studied. In this research, storage materials were identified with thermo-physical data being presented for different rocks (e.g. quartzite), super concrete, and other appropriate solid materials. Among the new materials being proposed like rocks from old quarries, an interesting option is the incorporation of solid waste material from old mines belonging to the Iberian Pyritic Belt. These are currently handled as byproducts of past mine activity, and can potentially constitute an environmental hazard due to their chemical (metal) content. This paper presents these materials, as part of a broad study to improve the current concept of solar energy storage for STE plants, and additionally presents a potentially valuable solution for environmental protection related to re-use of mining waste.

  4. Heat transfer enhancement through PCM thermal storage by use of copper fins

    Directory of Open Access Journals (Sweden)

    Rudonja Nedžad R.

    2016-01-01

    Full Text Available Enhancement of heat transfer over a cylinder shaped thermal energy storage filled by paraffin E53 by use of radial rectangular copper fins was analyzed. The thermo-physical features of the storage material are determined in separate experiments and implemented to Fluent software over UDF. Advanced thermal storage geometry comprehension and optimization required introduction of a parameter suitable for the analysis of heat transfer enhancement, so the ratio of heat transfer surfaces as a factor was proposed and applied. It is revealed that increase of the ratio of heat transfer surfaces leads to the decrease of melting time and vice versa. Numerical analysis, employing the 3D model built in Ansys software, observed storage reservoir geometries with variable number of longitudinal radial fins. The adjusted set of boundary conditions was carried out and both written in C language and implemented over UDF in order to define variable heat flux along the height of the heater. The comparison of acquired numerical and experimental results showed a strong correlation. Experimental validation of numerical results was done on the real TES apparatus. [Projekat Ministarstva nauke Republike Srbije, br. III42011, TR 33042 i OI 176006

  5. Preparation, thermal properties and thermal reliability of palmitic acid/expanded graphite composite as form-stable PCM for thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Sari, Ahmet; Karaipekli, Ali [Department of Chemistry, Gaziosmanpasa University, 60240 Tokat (Turkey)

    2009-05-15

    This study is focused on the preparation and characterization of thermal properties and thermal reliability of palmitic acid (PA)/expanded graphite (EG) composite as form-stable phase change material (PCM). The maximum mass fraction of PA retained in EG was found as 80 wt% without the leakage of PA in melted state even when it is heated over the melting point of PA. Therefore, the PA/EG (80/20 w/w%) composite was characterized as form-stable PCM. From differential scanning calorimetry (DSC) analysis, the melting and freezing temperatures and latent heats of the form-stable PCM were measured as 60.88 and 60.81 C and 148.36 and 149.66 J/g, respectively. Thermal cycling test showed that the composite PCM has good thermal reliability although it was subjected to 3000 melting/freezing cycles. Fourier transformation infrared (FT-IR) spectroscopic investigation indicated that it has good chemical stability after thermal cycling. Thermal conductivities of PA/EG composites including different mass fractions of EG (5%, 10%, 15% and 20%) were also measured. Thermal conductivity of form-stable PA/EG (80/20 w/w%) composite (0.60 W/mK) was found to be 2.5 times higher than that of pure PA (0.17 W/mK). Moreover, the increase in thermal conductivity of PA was confirmed by comparison of the melting and freezing times of pure PA with that of form-stable composite. Based on all results, it was concluded that the form-stable PA/EG (80/20 w/w%) has considerable latent heat energy storage potential because of its good thermal properties, thermal and chemical reliability and thermal conductivity. (author)

  6. Study on effectiveness of continuous solar dryer integrated with desiccant thermal storage for drying cocoa beans

    Directory of Open Access Journals (Sweden)

    Sari Farah Dina

    2015-03-01

    Full Text Available The main objective is to assess effectiveness of continuous solar dryer integrated with desiccant thermal storage for drying cocoa beans. Two type of desiccants were tested, molecular sieve 13× (Na86 [(AlO286·(SiO2106]·264H2O as an adsorbent type and CaCl2 as an absorbent type. The results revealed that during sunshine hours, the maximum temperature within the drying chamber varied from 40 °C to 54 °C. In average, it was 9–12 °C higher than ambient temperature. These temperatures are very suitable for drying cocoa beans. During off-sunshine hours, humidity of air inside the drying chamber was lower than ambient because of the desiccant thermal storage. Drying times for intermittent directs sun drying, solar dryer integrated with adsorbent, and solar dryer integrated with absorbent were 55 h, 41 h, and 30 h, respectively. Specific energy consumptions for direct sun drying, solar dryer integrated with adsorbent, and solar dryer integrated with absorber were 60.4 MJ/kg moist, 18.94 MJ/kg moist, and 13.29 MJ/kg moist, respectively. The main conclusion can be drawn here is that a solar dryer integrated with desiccant thermal storage makes drying using solar energy more effective in term of drying time and specific energy consumption.

  7. Design and experimental study of an integrated vapor chamber-thermal energy storage system

    Science.gov (United States)

    Kota, Krishna M.

    Future defense, aerospace and automotive technologies involve electronic systems that release high pulsed waste heat like during high power microwave and laser diode applications in tactical and combat aircraft, and electrical and electronic systems in hybrid electric vehicles, which will require the development of an efficient thermal management system. A key design issue is the need for fast charging so as not to overheat the key components. The goal of this work is to study the fabrication and technology implementation feasibility of a novel high energy storage, high heat flux passive heat sink. Key focus is to verify by theory and experiments, the practicability of using phase change materials as a temporary storage of waste heat for heat sink applications. The reason for storing the high heat fluxes temporarily is to be able to reject the heat at the average level when the heat source is off. Accordingly, a concept of a dual latent heat sink intended for moderate to low thermal duty cycle electronic heat sink applications is presented. This heat sink design combines the features of a vapor chamber with rapid thermal energy storage employing graphite foam inside the heat storage facility along with phase change materials and is attractive owing to its passive operation unlike some of the current thermal management techniques for cooling of electronics employing forced air circulation or external heat exchangers. In addition to the concept, end-application dependent criteria to select an optimized design for this dual latent heat sink are presented. A thermal resistance concept based design tool/model has been developed to analyze and optimize the design for experiments. The model showed that it is possible to have a dual latent heat sink design capable of handling 7 MJ of thermal load at a heat flux of 500 W/cm2 (over an area of 100 cm 2) with a volume of 0.072 m3 and weighing about 57.5 kg. It was also found that with such high heat flux absorption capability

  8. Thermal performance sensitivity studies in support of material modeling for extended storage of used nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Cuta, Judith M.; Suffield, Sarah R.; Fort, James A.; Adkins, Harold E.

    2013-08-15

    The work reported here is an investigation of the sensitivity of component temperatures of a storage system, including fuel cladding temperatures, in response to age-related changes that could degrade the design-basis thermal behavior of the system. Three specific areas of interest were identified for this study. • degradation of the canister backfill gas from pure helium to a mixture of air and helium, resulting from postulated leakage due to stress corrosion cracking (SCC) of canister welds • changes in surface emissivity of system components, resulting from corrosion or other aging mechanisms, which could cause potentially significant changes in temperatures and temperature distributions, due to the effect on thermal radiation exchange between components • changes in fuel and basket temperatures due to changes in fuel assembly position within the basket cells in the canister The purpose of these sensitivity studies is to provide a realistic example of how changes in the physical properties or configuration of the storage system components can affect temperatures and temperature distributions. The magnitudes of these sensitivities can provide guidance for identifying appropriate modeling assumptions for thermal evaluations extending long term storage out beyond 50, 100, 200, and 300 years.

  9. Smart Polyacrylonitrile (PAN) Nanofibers with Thermal Energy Storage and Retrieval Functionality

    Science.gov (United States)

    Cherry, De'Andre James

    Phase change materials (PCMs) are generally substances with a high heat of fusion in the process of solid to liquid phase change. The nature of PCMs make them efficient materials to store and retrieve large amounts of thermal energy. Presently, high efficiency thermal energy storage/retrieval in applications where flexibility and space saving are required, such as smart textiles, still remains as a challenge. In this study, lauric acid (LA) and myristic acid (MA) were combined to prepare a specific binary fatty acid eutectic (LA-MA) with a melting point near the operating body temperature of a human being and then encapsulated in polyacrylonitrile (PAN) nanofibers through the electrospinning technique. Functionalized PCM-enhanced PAN nanofibers containing LA-MA at 30%, 50%, 70% and 100% of the weight of the PAN were successfully synthesized. The morphological structures and thermal energy storage capacity of the PCM-enhanced PAN nanofibers were characterized by electron microscopy (EM) and differential scanning calorimetry (DSC). The novel PCM-enhanced PAN nanofibers maintained their cylindrical fiber morphology after multiple heating-cooling cycles and retained their latent heat storage functionality. Thus, it is envisioned that the prepared PCM-enhanced PAN nanofibers will find use in applications such as smart textiles where temperature regulation functionality is required.

  10. Direct solar thermal energy storage using a semitransparent PCM. Indoor experiment under constant incident radiation

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Makoto; Bando, Yoshiyuki; Kuraishi, Michio; Hahne, E.W.P.

    1987-07-10

    The effect of the optical thickness of a translucent PCM (phase change material) on the temperature distribution and the thermal energy storage efficiency was studied for a passive system of solar thermal energy storage, in which a plane layer of the PCM was directly heated and melted by the solar radiation. Paraffin wax was used as the PCM and a black dye was added to change its absorption coefficient. Samples comprised of the PCM layer and the insulating layer with the adiabatic rear side were tested using a sun simulator capable of constant incident radiation. A theoretical analysis was made by applying the concept of overall specific heat. As the results, the theoretical analysis was proved to be valid, and further it was clarified that the optical thickness of the PCM had a strong influence on the temperature distribution and the thermal energy storage efficiency. The PCM with small optical thickness was found to have greater efficiency because of inner melting. (8 figs, 2 tabs, 7 refs)

  11. Investigation of potential waste material insulating properties at different temperature for thermal storage application

    Science.gov (United States)

    Ali, T. Z. S.; Rosli, A. B.; Gan, L. M.; Billy, A. S.; Farid, Z.

    2013-12-01

    Thermal energy storage system (TES) is developed to extend the operation of power generation. TES system is a key component in a solar energy power generation plant, but the main issue in designing the TES system is its thermal capacity of storage materials, e.g. insulator. This study is focusing on the potential waste material acts as an insulator for thermal energy storage applications. As the insulator is used to absorb heat, it is needed to find suitable material for energy conversion and at the same time reduce the waste generation. Thus, a small-scale experimental testing of natural cooling process of an insulated tank within a confined room is conducted. The experiment is repeated by changing the insulator from the potential waste material and also by changing the heat transfer fluid (HTF). The analysis presented the relationship between heat loss and the reserved period by the insulator. The results show the percentage of period of the insulated tank withstands compared to tank insulated by foam, e.g. newspaper reserved the period of 84.6% as much as foam insulated tank to withstand the heat transfer of cooking oil to the surrounding. The paper finally justifies the most potential waste material as an insulator for different temperature range of heat transfer fluid.

  12. Thermal Mode of Tanks for Storage Fuel of Thermal Power Plants and Boiler with the Influence of Engineering Facilities in the Area of their Placement

    Science.gov (United States)

    Polovnikov, V. Yu.; Makhsutbek, F. T.; Ozhikenova, Zh. F.

    2016-02-01

    This paper describes the numerical modeling of heat transfer in the area placing of the tank for storage fuel of thermal power plant and boiler with the influence of engineering construction. We have established that the presence of engineering structures in the area of placing of the tank for storage fuel of thermal power plant and boiler have little effect on the change of heat loss.

  13. Simplified Building Thermal Model Used for Optimal Control of Radiant Cooling System

    Directory of Open Access Journals (Sweden)

    Lei He

    2016-01-01

    Full Text Available MPC has the ability to optimize the system operation parameters for energy conservation. Recently, it has been used in HVAC systems for saving energy, but there are very few applications in radiant cooling systems. To implement MPC in buildings with radiant terminals, the predictions of cooling load and thermal environment are indispensable. In this paper, a simplified thermal model is proposed for predicting cooling load and thermal environment in buildings with radiant floor. In this thermal model, the black-box model is introduced to derive the incident solar radiation, while the genetic algorithm is utilized to identify the parameters of the thermal model. In order to further validate this simplified thermal model, simulated results from TRNSYS are compared with those from this model and the deviation is evaluated based on coefficient of variation of root mean square (CV. The results show that the simplified model can predict the operative temperature with a CV lower than 1% and predict cooling loads with a CV lower than 10%. For the purpose of supervisory control in HVAC systems, this simplified RC thermal model has an acceptable accuracy and can be used for further MPC in buildings with radiation terminals.

  14. Thermal storage in a heat pump heated living room floor for urban district power balancing - effects on thermal comfort, energy loss and costs for residents

    NARCIS (Netherlands)

    Leeuwen, van R.P.; Wit, de J.B.; Fink, J.; Smit, G.J.M.

    2014-01-01

    For the Dutch smart grid demonstration project Meppelenergie, the effects of controlled thermal energy storage within the floor heating structure of a living room by a heat pump are investigated. Storage possibilities are constrained by room operative and floor temperatures. Simulations indicate lim

  15. Using Encapsulated Phase Change Material in Thermal Energy Storage for Baseload Concentrating Solar Power (EPCM-TES)

    Energy Technology Data Exchange (ETDEWEB)

    Mathur, Anoop [Terrafore Technologies LLC, Minneapolis, MN (United States)

    2013-12-15

    Terrafore successfully demonstrated and optimized the manufacturing of capsules containing phase-changing inorganic salts. The phase change was used to store thermal energy collected from a concentrating solar-power plant as latent heat. This latent heat, in addition to sensible heat increased the energy density (energy stored per unit weight of salt) by over 50%, thus requiring 40% less salt and over 60% less capsule container. Therefore, the cost to store high-temperature thermal energy collected in a concentrating solar power plant will be reduced by almost 40% or more, as compared to conventional two-tank, sensible-only storage systems. The cost for thermal energy storage (TES) system is expected to achieve the Sun Shot goal of $15 per kWh(t). Costs associated with poor heat-transfer in phase change materials (PCM) were also eliminated. Although thermal energy storage that relies on the latent heat of fusion of PCM improves energy density by as much as 50%, upon energy discharge the salt freezes and builds on the heat transfer surfaces. Since these salts have low thermal conductivity, large heat-transfer areas, or larger conventional heat-exchangers are needed, which increases costs. By encapsulating PCM in small capsules we have increased the heat transfer area per unit volume of salt and brought the heat transfer fluid in direct contact with the capsules. These two improvements have increased the heat transfer coefficient and boosted heat transfer. The program was successful in overcoming the phenomenon of melt expansion in the capsules, which requires the creation of open volume in the capsules or shell to allow for expansion of the molten salt on melting and is heated above its melting point to 550°C. Under contract with the Department of Energy, Terrafore Inc. and Southwest Research Institute, developed innovative method(s) to economically create the open volume or void in the capsule. One method consists of using a sacrificial polymer coating as the

  16. Thermodynamic model of a thermal storage air conditioning system with dynamic behavior

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, E; Wen, SY; Shi, L; da Silva, AK

    2013-12-01

    A thermodynamic model was developed to predict transient behavior of a thermal storage system, using phase change materials (PCMs), for a novel electric vehicle climate conditioning application. The main objectives of the paper are to consider the system's dynamic behavior, such as a dynamic air flow rate into the vehicle's cabin, and to characterize the transient heat transfer process between the thermal storage unit and the vehicle's cabin, while still maintaining accurate solution to the complex phase change heat transfer. The system studied consists of a heat transfer fluid circulating between either of the on-board hot and cold thermal storage units, which we refer to as thermal batteries, and a liquid-air heat exchanger that provides heat exchange with the incoming air to the vehicle cabin. Each thermal battery is a shell-and-tube configuration where a heat transfer fluid flows through parallel tubes, which are surrounded by PCM within a larger shell. The system model incorporates computationally inexpensive semianalytic solution to the conjugated laminar forced convection and phase change problem within the battery and accounts for airside heat exchange using the Number of Transfer Units (NTUs) method for the liquid-air heat exchanger. Using this approach, we are able to obtain an accurate solution to the complex heat transfer problem within the battery while also incorporating the impact of the airside heat transfer on the overall system performance. The implemented model was benchmarked against a numerical study for a melting process and against full system experimental data for solidification using paraffin wax as the PCM. Through modeling, we demonstrate the importance of capturing the airside heat exchange impact on system performance, and we investigate system response to dynamic operating conditions, e.g., air recirculation. (C) 2013 Elsevier Ltd. All rights reserved.

  17. Thermal properties in phase change wallboard room based on air conditioning cold storage

    Institute of Scientific and Technical Information of China (English)

    陈其针; 刘鑫; 牛润萍; 王琳

    2009-01-01

    By comparing the thermal performance parameters of an ordinary wall room with a phase change wall (PCW) room,the effect of phase change wallboard on the fluctuation of temperature in air-conditioning room in summer was studied. And PCW room and an ordinary wall room,which are cooled by air-conditioner,were built up. Differential scanning calorimetry (DSC) was used to test the temperature field and heat flow fluctuation in these rooms. Through analyzing the data tested,it is found that the mean temperature of PCW is lower than that of ordinary wall room by 1-2 ℃,and PCW can lower the heat flow by 4.6 W/m2. Combining phase change material to building envelope can lower the indoor temperature,make the room thermal comfortable,and cut down the turn-on-and-off frequency of air-conditioner,the primary investment and operating costs. It alleviates urgent need of the electric power. Building envelope which contains phase change wallboard can improve the indoor thermal environment,and decrease energy consumption in buildings. Phase change wallboard can make impressive effect on energy efficiency of buildings.

  18. Investigation of thermal effect on exterior wall surface of building material at urban city area

    Energy Technology Data Exchange (ETDEWEB)

    Md Din, Mohd Fadhil; Dzinun, Hazlini; Ponraj, M.; Chelliapan, Shreeshivadasan; Noor, Zainura Zainun [Institute of Environmental Water Resources and Management (IPASA), Faculty of Civil Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia); Remaz, Dilshah [Faculty of Built Environment, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia); Iwao, Kenzo [Nagoya Institute of Technology, Nagoya (Japan)

    2012-07-01

    This paper describes the investigation of heat impact on the vertical surfaces of buildings based on their thermal behavior. The study was performed based on four building materials that is commonly used in Malaysia; brick, concrete, granite and white concrete tiles. The thermal performances on the building materials were investigated using a surface temperature sensor, data logging system and infrared thermography. Results showed that the brick had the capability to absorb and store heat greater than other materials during the investigation period. The normalized heat (total heat/solar radiation) of the brick was 0.093 and produces high heat (51% compared to granite), confirming a substantial amount of heat being released into the atmosphere through radiation and convection. The most sensitive material that absorbs and stores heat was in the following order: brick > concrete > granite > white concrete tiles. It was concluded that the type of exterior wall material used in buildings had significant impact to the environment.

  19. Investigation of thermal effect on exterior wall surface of building material at urban city area

    Directory of Open Access Journals (Sweden)

    Mohd Fadhil Md Din, Hazlini Dzinun, M. Ponraj, Shreeshivadasan Chelliapan, Zainura Zainun Noor, Dilshah Remaz, Kenzo Iwao

    2012-01-01

    Full Text Available This paper describes the investigation of heat impact on the vertical surfaces of buildings based on their thermal behavior. The study was performed based on four building materials that is commonly used in Malaysia; brick, concrete, granite and white concrete tiles. The thermal performances on the building materials were investigated using a surface temperature sensor, data logging system and infrared thermography. Results showed that the brick had the capability to absorb and store heat greater than other materials during the investigation period. The normalized heat (total heat/solar radiation of the brick was 0.093 and produces high heat (51% compared to granite, confirming a substantial amount of heat being released into the atmosphere through radiation and convection. The most sensitive material that absorbs and stores heat was in the following order: brick > concrete > granite > white concrete tiles. It was concluded that the type of exterior wall material used in buildings had significant impact to the environment.

  20. Design and modelling of an innovative three-stage thermal storage system for direct steam generation CSP plants

    Science.gov (United States)

    Garcia, Pierre; Vuillerme, Valéry; Olcese, Marco; El Mourchid, Nadim

    2016-05-01

    Thermal Energy Storage systems (TES) for a Direct Steam Generation (DSG) solar plant feature preferably three stages in series including a latent heat storage module so that steam can be recovered with a limited temperature loss. The storage system designed within the Alsolen Sup project is characterized by an innovative combination of sensible and latent modules. A dynamic model of this three-stage storage has been developed and applied to size the storage system of the Alsolen Sup® plant demonstrator at CEA Cadarache. Results of this simulation show that this promising concept is an efficient way to store heat in DSG solar plants.