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Thermal Battery
A thermal energy battery is a physical structure used for the purpose of storing and releasing thermal energy—see also thermal energy storage. Such a thermal battery (a.k.a. TBat) allows energy available at one time to be temporarily stored and then released at another time. The basic principles involved in a thermal battery occur at the atomic level of matter, with energy being added to or taken from either a solid mass or a liquid volume which causes the substance's temperature to change. Some thermal batteries also involve causing a substance to transition thermally through a phase transition which causes even more energy to be stored and released due to the delta enthalpy of fusion or delta enthalpy of vaporization. History of thermal batteries Thermal batteries are very common, and include such familiar items as a hot water bottle. Early examples of thermal batteries include stone and mud cook stoves, rocks placed in fires, and kilns. While stoves and kilns are ove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat
In thermodynamics, heat is defined as the form of energy crossing the boundary of a thermodynamic system by virtue of a temperature difference across the boundary. A thermodynamic system does not ''contain'' heat. Nevertheless, the term is also often used to refer to the thermal energy contained in a system as a component of its internal energy and that is reflected in the temperature of the system. For both uses of the term, heat is a form of energy. An example of formal vs. informal usage may be obtained from the right-hand photo, in which the metal bar is "conducting heat" from its hot end to its cold end, but if the metal bar is considered a thermodynamic system, then the energy flowing within the metal bar is called internal energy, not heat. The hot metal bar is also transferring heat to its surroundings, a correct statement for both the strict and loose meanings of ''heat''. Another example of informal usage is the term '' heat content'', used despite the fact that p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primary Battery
A primary battery or primary cell is a battery (a galvanic cell) that is designed to be used once and discarded, and not recharged with electricity and reused like a secondary cell (rechargeable battery). In general, the electrochemical reaction occurring in the cell is not reversible, rendering the cell unrechargeable. As a primary cell is used, chemical reactions in the battery use up the chemicals that generate the power; when they are gone, the battery stops producing electricity. In contrast, in a secondary cell, the reaction can be reversed by running a current into the cell with a battery charger to recharge it, regenerating the chemical reactants. Primary cells are made in a range of standard sizes to power small household appliances such as flashlights and portable radios. Primary batteries make up about 90% of the $50 billion battery market, but secondary batteries have been gaining market share. About 15 billion primary batteries are thrown away worldwide every year, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Ground Source Heat Pump Association
Established in 1987, the International Ground Source Heat Pump Association (IGSHPA) is a nonprofit, membership-based organization that promotes geothermal heat pump technology. It was a outreach unit of the College of Engineering, Architecture and Technology (CEAT) at Oklahoma State University until 2020. In June 2020, the OSU Board of Regents voted to approve a transfer of IGSHPA, its intellectual property, and assets to the control of the Geothermal Exchange Organization (GEO). Primary Efforts IGSHPA is the main organization for establishing standards of practice and standards of design for Geothermal heat pump, Geothermal Heat Pump (GHP) systems in the US. Related organizations have been formed in other countries on four continents, including Australia, Canada, China, India, South Korea, and Sweden. Conferences Each year the association hosts an annual conference for people such as manufacturers, contractors, distributors, and drillers. Standards IGSHPA sets and revises stan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geothermal Heat Pump
A ground source heat pump (also geothermal heat pump) is a heating/cooling system for buildings that uses a type of heat pump to transfer heat to or from the ground, taking advantage of the relative constancy of temperatures of the earth through the seasons. Ground source heat pumps (GSHPs) – or geothermal heat pumps (GHP) as they are commonly termed in North America – are among the most energy-efficient technologies for providing HVAC and water heating, using far less energy than can be achieved by burning a fuel in a boiler/furnace or by use of resistive electric heaters. Efficiency is given as a coefficient of performance (CoP) which is typically in the range 3 – 6, meaning that the devices provide 3 – 6 units of heat for each unit of electricity used. Setup costs are higher than for other heating systems due to the requirement to install ground loops over large areas or drill bore holes, and for this reason air source heat pumps are often used instead. Thermal prope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground-coupled Heat Exchanger
A ground-coupled heat exchanger is an underground heat exchanger that can capture heat from and/or dissipate heat to the ground. They use the Earth's near constant subterranean temperature to warm or cool air or other fluids for residential, agricultural or industrial uses. If building air is blown through the heat exchanger for heat recovery ventilation, they are called earth tubes (or Canadian well, Provençal well, Solar chimney, also termed earth cooling tubes, earth warming tubes, earth-air heat exchangers (EAHE or EAHX), air-to-soil heat exchanger, earth channels, earth canals, earth-air tunnel systems, ground tube heat exchanger, hypocausts, subsoil heat exchangers, thermal labyrinths, underground air pipes, and others). Earth tubes are often a viable and economical alternative or supplement to conventional central heating or air conditioning systems since there are no compressors, chemicals or burners and only blowers are required to move the air. These are used for either ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Energy Storage
Thermal energy storage (TES) is achieved with widely different technologies. Depending on the specific technology, it allows excess thermal energy to be stored and used hours, days, months later, at scales ranging from the individual process, building, multiuser-building, district, town, or region. Usage examples are the balancing of energy demand between daytime and nighttime, storing summer heat for winter heating, or winter cold for summer air conditioning (Seasonal thermal energy storage). Storage media include water or ice-slush tanks, masses of native earth or bedrock accessed with heat exchangers by means of boreholes, deep aquifers contained between impermeable strata; shallow, lined pits filled with gravel and water and insulated at the top, as well as eutectic solutions and phase-change materials. Other sources of thermal energy for storage include heat or cold produced with heat pumps from off-peak, lower cost electric power, a practice called peak shaving; heat fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Of Solution
In thermochemistry, the enthalpy of solution ( heat of solution or enthalpy of solvation) is the enthalpy change associated with the dissolution of a substance in a solvent at constant pressure resulting in infinite dilution. The enthalpy of solution is most often expressed in kJ/ mol at constant temperature. The energy change can be regarded as being made of three parts: the endothermic breaking of bonds within the solute and within the solvent, and the formation of attractions between the solute and the solvent. An ideal solution has a null enthalpy of mixing. For a non-ideal solution it is an excess molar quantity. Energetics Dissolution by most gases is exothermic. That is, when a gas dissolves in a liquid solvent, energy is released as heat, warming both the system (i.e. the solution) and the surroundings. The temperature of the solution eventually decreases to match that of the surroundings. The equilibrium, between the gas as a separate phase and the gas in solution, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endothermic
In thermochemistry, an endothermic process () is any thermodynamic process with an increase in the enthalpy (or internal energy ) of the system.Oxtoby, D. W; Gillis, H.P., Butler, L. J. (2015).''Principle of Modern Chemistry'', Brooks Cole. p. 617. In such a process, a closed system usually absorbs thermal energy from its surroundings, which is heat transfer into the system. Thus, an endothermic reaction generally leads to an increase in the temperature of the system and a decrease in that of the surroundings. It may be a chemical process, such as dissolving ammonium nitrate () in water (), or a physical process, such as the melting of ice cubes. The term was coined by 19th-century French chemist Marcellin Berthelot. The opposite of an endothermic process is an exothermic process, one that releases or "gives out" energy, usually in the form of heat and sometimes as electrical energy. Thus in each term (endothermic and exothermic) the prefix refers to where heat (or electrical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instant Cold Pack
An ice pack or gel pack is a portable bag filled with water, refrigerant gel, or liquid, meant to provide cooling. They can be divided into the reusable type, which works as a thermal mass and requires freezing, or the instant type, which cools itself down using chemicals but can only be used once. The instant type is generally limited to medical use as a cold compress to alleviate the pain of minor injuries, while the reusable type is both used as a cold compress and to keep food cool in portable coolers or in insulated shipping containers to keep products cool during transport. Reusable packs To be prepared for use, the pack is first placed in a freezer. Both ice and other non-toxic refrigerants (mostly water) can absorb a considerable amount of heat before they warm above .` Ice packs are used in coolers to keep perishable foods (especially meats, dairy products, eggs, etc.) below the danger zone when outside a refrigerator or freezer, and to keep drinks pleasantly cool ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hand Warmer
Hand warmers are small (mostly disposable) packets which are held in the hand and produce heat on demand to warm cold hands. They are commonly used in outdoor activities. Other types of warmers are available to provide soothing heat for muscular or joint aches. History The hand and foot warmer was first patented by Jonathan T. Ellis of New Jersey in 1891, though no evidence exists that it was ever produced. The first commercially produced hand warmer was created by Japanese inventor Niichi Matoba. Matoba received a patent for applying the principle of an oxidation reaction that produces heat by means of platinum catalysis. He then devoted his time to researching how to make the product suitable for practical use. In 1923, he manufactured a prototype of his device naming it HAKUKIN-kairo (HAKKIN warmer). A version of these original portable hand warmers is still produced in Japan. Types Air activated (iron) Air-activated hand warmers contain cellulose, iron, activated carbon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrotechnic Heat Source
A pyrotechnic heat source, also called heat pellet, is a pyrotechnic device based on a pyrotechnic composition with a suitable igniter. Its role is to produce controlled amount of heat. Pyrotechnic heat sources are usually based on thermite-like (or sometimes delay composition-like) fuel-oxidizer compositions with slow burn rate, high production of heat at desired temperature, and low to zero production of gases. Pyrotechnic heat sources can be activated by multiple means. Electric match and percussion cap are the most common ones. Pyrotechnic heat sources are often used for activation of thermal battery, thermal batteries, where they serve to melt the electrolyte. There are two main types of design. One uses a fuze strip (containing barium chromate and powdered zirconium metal in a ceramic paper) along the edge of the heat pellets to initiate burning. The fuze strip is typically fired by an electric match, electrical igniter or squib (explosive), squib by application of electric ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
