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Design and Installation Manual for Thermal Energy Storage

Description: 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.
Date: February 1979
Creator: Cole, Roger Lynn; Nield, Kenneth J.; Rohde, Raymond R. & Wolosewicz, R. M.
Partner: UNT Libraries Government Documents Department

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

Description: 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.
Date: May 15, 2013
Creator: Qiu, Songgang
Partner: UNT Libraries Government Documents Department

Cost-Effective Solar Thermal Energy Storage: Thermal Energy Storage With Supercritical Fluids

Description: Broad Funding Opportunity Announcement Project: UCLA and JPL are creating cost-effective storage systems for solar thermal energy using new materials and designs. A major drawback to the widespread use of solar thermal energy is its inability to cost-effectively supply electric power at night. State-of-the-art energy storage for solar thermal power plants uses molten salt to help store thermal energy. Molten salt systems can be expensive and complex, which is not attractive from a long-term investment standpoint. UCLA and JPL are developing a supercritical fluid-based thermal energy storage system, which would be much less expensive than molten-salt-based systems. The team’s design also uses a smaller, modular, single-tank design that is more reliable and scalable for large-scale storage applications.
Date: February 1, 2011
Partner: UNT Libraries Government Documents Department

Evaluation of Representative Smart Grid Investment Grant Project Technologies: Thermal Energy Storage

Description: This document is one of a series of reports estimating the benefits of deploying technologies similar to those implemented on the Smart Grid Investment Grant (SGIG) projects. Four technical reports cover the various types of technologies deployed in the SGIG projects, distribution automation, demand response, energy storage, and renewables integration. A fifth report in the series examines the benefits of deploying these technologies on a national level. This technical report examines the impacts of energy storage technologies deployed in the SGIG projects.
Date: February 14, 2012
Creator: Tuffner, Francis K. & Bonebrake, Christopher A.
Partner: UNT Libraries Government Documents Department

Novel Molten Salts Thermal Energy Storage for Concentrating Solar Power Generation

Description: 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 go/no-go goals stipulated by ...
Date: October 23, 2013
Creator: Reddy, Ramana G.
Partner: UNT Libraries Government Documents Department

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

Description: 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.
Date: September 26, 2013
Creator: Faghri, Amir; Bergman, Theodore L & Pitchumani, Ranga
Partner: UNT Libraries Government Documents Department

Development and Performance Evaluation of High Temperature Concrete for Thermal Energy Storage for Solar Power Generation

Description: 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 ºC to 600 ºC) 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 ...
Date: March 31, 2013
Creator: R. Panneer Selvam, Micah Hale and Matt strasser
Partner: UNT Libraries Government Documents Department

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

Description: The objective of this project is to research and develop a thermal energy storage system (operating range 3000C – 450 0C ) 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.
Date: September 4, 2012
Creator: Goswami, D. Y.
Partner: UNT Libraries Government Documents Department

Applications of cogeneration with thermal energy storage technologies

Description: The Pacific Northwest Laboratory (PNL) leads the U.S. Department of Energy`s Thermal Energy Storage (TES) Program. The program focuses on developing TES for daily cycling (diurnal storage), annual cycling (seasonal storage), and utility-scale applications [utility thermal energy storage (UTES)]. Several of these storage technologies can be used in a new or an existing power generation facility to increase its efficiency and promote the use of the TES technology within the utility and the industrial sectors. The UTES project has included a study of both heat storage and cool storage systems for different utility-scale applications. The study reported here has shown that an oil/rock diurnal TES system, when integrated with a simple gas turbine cogeneration system, can produce on-peak power for $0.045 to $0.06 /kWh, while supplying a 24-hour process steam load. The molten salt storage system was found to be less suitable for simple as well as combined-cycle cogeneration applications. However, certain advanced TES concepts and storage media could substantially improve the performance and economic benefits. In related study of a chill TES system was evaluated for precooling gas turbine inlet air, which showed that an ice storage system could be used to effectively increase the peak generating capacity of gas turbines when operating in hot ambient conditions.
Date: March 1, 1995
Creator: Somasundaram, S.; Katipamula, S. & Williams, H.R.
Partner: UNT Libraries Government Documents Department

Site-specific investigations of aquifer thermal energy storage for space and process cooling

Description: The Pacific Northwest Laboratory (PNL) has completed three preliminary site-specific feasibility studies that investigated using aquifer thermal energy storage (ATES) to reduce space and process cooling costs. Chilled water stored in an ATES system could be used to meet all or part of the process and/or space cooling loads at the three facilities investigated. The work was sponsored by the US Department of Energy&#x27;s (DOE) Office of Energy Management. The ultimate goal of DOE&#x27;s Thermal Energy Storage Program is to successfully transfer ATES technology to industrial and commercial sectors. The primary objective of this study was to identify prospective sites and determine the technical and economic feasibility of implementing chill ATES technology. A secondary objective was to identify site-specific factors promoting or inhibiting the application of chill ATES technology so that other potentially attractive sites could be more easily identified and evaluated. A preliminary investigation of the feasibility of commercializing chill ATES in automotive assembly facilities was completed. The results suggested that automotive assembly facilities was completed. The results suggested that automotive assembly facilities represent a good entry market for chill ATES, if the system is cost-effective. As a result, this study was undertaken to identify and evaluate prospective chill ATES applications in the automotive industry. The balance of the report contains two main sections. Section 2.0 describes the site identification process. Site feasibility is addressed in Section 3.0. Overall study conclusions and recommendations are than presented in Section 4.0.
Date: August 1, 1991
Creator: Brown, D R; Hattrup, M P & Watts, R L
Partner: UNT Libraries Government Documents Department

Thermal Energy Storage

Description: Advanced Research Projects Agency-Energy project sheet summarizing general information about the 15 projects that are a part of the High Energy Advanced Thermal Storage (HEATS) program including project goals, innovation needs, and potential impacts.
Date: May 21, 2012
Creator: United States. Advanced Research Projects Agency-Energy.
Partner: UNT Libraries Government Documents Department

Deep Eutectic Salt Formulations Suitable as Advanced Heat Transfer Fluids

Description: Concentrating solar power (CSP) facilities are comprised of many miles of fluid-filled pipes arranged in large grids with reflective mirrors used to capture radiation from the sun. Solar radiation heats the fluid which is used to produce steam necessary to power large electricity generation turbines. Currently, organic, oil-based fluid in the pipes has a maximum temperature threshold of 400 °C, allowing for the production of electricity at approximately 15 cents per kilowatt hour. The DOE hopes to foster the development of an advanced heat transfer fluid that can operate within higher temperature ranges. The new heat transfer fluid, when used with other advanced technologies, could significantly decrease solar electricity cost. Lower costs would make solar thermal electricity competitive with gas and coal and would offer a clean, renewable source of energy. Molten salts exhibit many desirable heat transfer qualities within the range of the project objectives. Halotechnics developed advanced heat transfer fluids (HTFs) for application in solar thermal power generation. This project focused on complex mixtures of inorganic salts that exhibited a high thermal stability, a low melting point, and other favorable characteristics. A high-throughput combinatorial research and development program was conducted in order to achieve the project objective. Over 19,000 candidate formulations were screened. The workflow developed to screen various chemical systems to discover salt formulations led to mixtures suitable for use as HTFs in both parabolic trough and heliostat CSP plants. Furthermore, salt mixtures which will not interfere with fertilizer based nitrates were discovered. In addition for use in CSP, the discovered salt mixtures can be applied to electricity storage, heat treatment of alloys and other industrial processes.
Date: July 22, 2013
Creator: Raade, Justin; Roark, Thomas; Vaughn, John & Bradshaw, Robert
Partner: UNT Libraries Government Documents Department

Solar Two

Description: Solar Two is a concentrating solar power plant that can supply electric power on demand to the local utility, Southern California Edison Company. It can do so because it operates not only during sunny parts of the day, but it can store enough thermal energy from the sun to operate during cloudy periods and after dark, for up to three hours, at its rated output of 10 megawatts (MW). For the first time ever, a utility scale solar power plant can supply electricity when the utility needs it most, to satisfy the energy requirements of its customers.
Date: April 1, 1998
Partner: UNT Libraries Government Documents Department

Summary Report for Concentrating Solar Power Thermal Storage Workshop: New Concepts and Materials for Thermal Energy Storage and Heat-Transfer Fluids, May 20, 2011

Description: 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.
Date: August 1, 2011
Creator: Glatzmaier, G.
Partner: UNT Libraries Government Documents Department

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

Description: 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.
Date: March 1989
Creator: Hoffman, H. W. & Tomlinson, J. J.
Partner: UNT Libraries Government Documents Department

Seasonal thermal energy storage in unsaturated soils: Model development and field validation

Description: This report summarizes ten years of activity carried out at the Earth Sciences Division of the Lawrence Berkeley Laboratory (LBI) in the subject of seasonal storage of thermal energy in unsaturated soils. The objectives of the work were to make a conceptual study of this type of storage, to offer guidelines for planning and evaluation of the method, to produce models and simulation for an actual field experiment, to participate in an on-line data analysis of experimental results. and to evaluate the results in terms of the validation of the concept, models and the experimental techniques. The actual field experiments were performed in Beer-Sheva, Israel. Details of engineering and field operations are not included in this report.
Date: June 1, 1991
Creator: Doughty, C. & Nir, Aharon, Tsang, Chin-Fu
Partner: UNT Libraries Government Documents Department

Advanced Thermal Storage System with Novel Molten Salt: December 8, 2011 - April 30, 2013

Description: 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.
Date: May 1, 2013
Creator: Jonemann, M.
Partner: UNT Libraries Government Documents Department

Modelling Concentrating Solar Power with Thermal Energy Storage for Integration Studies (Presentation)

Description: Concentrating solar power with thermal energy storage (CSP-TES) can provide multiple benefits to the grid, including low marginal cost energy and the ability to levelize load, provide operating reserves, and provide firm capacity. It is challenging to properly value the integration of CSP because of the complicated nature of this technology. Unlike completely dispatchable fossil sources, CSP is a limited energy resource, depending on the hourly and daily supply of solar energy. To optimize the use of this limited energy, CSP-TES must be implemented in a production cost model with multiple decision variables for the operation of the CSP-TES plant. We develop and implement a CSP-TES plant in a production cost model that accurately characterizes the three main components of the plant: solar field, storage tank, and power block. We show the effect of various modelling simplifications on the value of CSP, including: scheduled versus optimized dispatch from the storage tank and energy-only operation versus co-optimization with ancillary services.
Date: October 1, 2013
Creator: Hummon, M.; Jorgenson, J.; Denholm, P. & Mehos, M.
Partner: UNT Libraries Government Documents Department

An Analysis of Concentrating Solar Power with Thermal Energy Storage in a California 33% Renewable Scenario (Report Summary) (Presentation)

Description: This analysis evaluates CSP with TES in a scenario where California derives 33% of its electricity from renewable energy sources. It uses a commercial grid simulation tool to examine the avoided operational and capacity costs associated with CSP and compares this value to PV and a baseload generation with constant output. Overall, the analysis demonstrates several properties of dispatchable CSP, including the flexibility to generate during periods of high value and avoid generation during periods of lower value. Of note in this analysis is the fact that significant amount of operational value is derived from the provision of reserves in the case where CSP is allowed to provide these services. This analysis also indicates that the 'optimal' configuration of CSP could vary as a function of renewable penetration, and each configuration will need to be evaluated in terms of its ability to provide dispatchable energy, reserves, and firm capacity. The model can be used to investigate additional scenarios involving alternative technology options and generation mixes, applying these scenarios within California or in other regions of interest.
Date: April 1, 2013
Creator: Denholm, P.; Wan, Y. H.; Hummon, M. & Mehos, M.
Partner: UNT Libraries Government Documents Department

Thermocline Thermal Storage Test for Large-Scale Solar Thermal Power Plants

Description: Solar thermal-to-electric power plants have been tested and investigated at Sandia National Laboratories (SNL) since the late 1970s, and thermal storage has always been an area of key study because it affords an economical method of delivering solar-electricity during non-daylight hours. This paper describes the design considerations of a new, single-tank, thermal storage system and details the benefits of employing this technology in large-scale (10MW to 100MW) solar thermal power plants. Since December 1999, solar engineers at Sandia National Laboratories' National Solar Thermal Test Facility (NSTTF) have designed and are constructing a thermal storage test called the thermocline system. This technology, which employs a single thermocline tank, has the potential to replace the traditional and more expensive two-tank storage systems. The thermocline tank approach uses a mixture of silica sand and quartzite rock to displace a significant portion of the volume in the tank. Then it is filled with the heat transfer fluid, a molten nitrate salt. A thermal gradient separates the hot and cold salt. Loading the tank with the combination of sand, rock, and molten salt instead of just molten salt dramatically reduces the system cost. The typical cost of the molten nitrate salt is $800 per ton versus the cost of the sand and rock portion at $70 per ton. Construction of the thermocline system will be completed in August 2000, and testing will run for two to three months. The testing results will be used to determine the economic viability of the single-tank (thermocline) storage technology for large-scale solar thermal power plants. Also discussed in this paper are the safety issues involving molten nitrate salts and other heat transfer fluids, such as synthetic heat transfer oils, and the impact of these issues on the system design.
Date: August 14, 2000
Partner: UNT Libraries Government Documents Department

Performance of the Solar Two central receiver power plant

Description: Solar Two is a utility-led project to promote the commercialization of solar power towers by retrofitting the Solar One pilot plant from a water/steam-based system to a molten salt system. Solar Two is capable of producing 10 MW(e) net electricity with enough thermal storage capacity to operate the turbine for three hours after sunset. The plant was turned over to its operations and maintenance contractor in February 1998, marking transition from start-up to the test and evaluation phase. Solar Two has collected as much as 230 MWh thermal and generated as much as 72 MWh(e) gross electricity in one day. The plant has demonstrated dispatchability after dark, during clouds, and during sunshine hours. To date, Solar Two has collected thermal energy at a maximum rate of 39 MW(t) and generated gross electricity at a maximum rate of 11.1 MW(e). Important lessons have been learned in the areas of heat trace, valve selection, materials of construction, and steam generator design. Testing has begun in a number of areas relating to receiver performance, storage tank performance, salt chemistry, overnight thermal conditioning, electricity dispatching, performance monitoring and evaluation, availability tracking, and receiver controls.
Date: September 1, 1998
Creator: Prairie, M.R.; Pacheco, J.E.; Gilbert, R.L.; Reilly, H.E.; Speidel, P.J. & Kelly, B.D.
Partner: UNT Libraries Government Documents Department

Thermal Energy Storage for the Small Packaged Terminal Air Conditioning Unit. Quarterly progress report, February 2000

Description: To finalize the IceBear design for full-scale production, build two preproduction prototypes, and confirm cost projections for production and market analysis. The 5 tasks being carried out are: Task 1--Finalize thermal energy storage tank design; Task 2--Finalize internal heat exchanger; Task 3--Finalize refrigerant management and control components; Task 4--Preproduction prototype laboratory testing; and Task 5--Reporting.
Date: February 1, 2000
Partner: UNT Libraries Government Documents Department

Aquifer thermal energy storage. International symposium: Proceedings

Description: 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.
Date: May 1, 1995
Partner: UNT Libraries Government Documents Department

Thermophysical properties and behavioral characteristics of phase-change materials

Description: The primary and near-term objective of the project is to compile a handbook of compounds and mixtures that melt in the range of 90 to 250/sup 0/C and which are suitable for isothermal heat storage. Organic compounds have been screened according to bulk price, thermal stability, and safety. Compounds were selected for further consideration if they cost less than $1.10/kg and if encyclopedia articles or handbooks indicated that they were reasonably stable chemically and were not toxic or otherwise hazardous. Of seven compounds thus selected, four (urea, phthalimide, adipic acid, phthalic anhydride) have been examined by DSC and other methods. The differential scanning calorimeter was used with two fairly well-characterized PCM&#x27;s to test its applicability for rapidly evaluating thermal decomposition and supercooling. With Na/sub 2/SO/sub 4/ . 10H/sub 2/O, DSC data indicated (a) decrease in heat of transition with thermal cycling, and (b) considerable supercooling; with 3 to 6 percent borax added, supercooling was greatly lessened but not entirely eliminated. Measurements with paraffin wax showed that this material does not supercool nor does it degrade in thermal performance with cycling. The DSC results with these two materials confirmed (and extended) thermal performance characteristics obtained by other means. However, studies of supercooling in urea and in phthalimide suggested that DSC techniques may magnify the extent of supercooling at elevated temperatures.
Date: January 1, 1977
Creator: Cantor, S
Partner: UNT Libraries Government Documents Department