Showing papers on "Thermal energy published in 1989"
Patent•
03 May 1989
TL;DR: In this article, a traveling wave device is used to obtain energy from high electrical charge density entities, such as an electric vehicle (EV), which is then used to generate a subsequent EV.
Abstract: Disclosed are apparatus and method for obtaining energy from high electrical charge density entities. The energy may be received by the conductor of a traveling wave device positioned along the path which the propagating entities follow. Multiple traveling wave devices may be combined. Energy output from a traveling wave device may also be directed to the generation of a subsequent such entity. Thermal energy may also be obtained from an EV.
184 citations
TL;DR: The momentum potential theory of time-stationary fluctuating flows is briefly reviewed and then extended to include energy flux carried by momentum fluctuations in this paper, where the mean energy flux can be expressed as a linear superposition of mean, turbulent, acoustic and thermal components.
95 citations
Patent•
19 May 1989
TL;DR: In this paper, an illustrative embodiment of the present invention, a cogeneration facility combined with means for producing CO 2 includes an internal combustion engine that drives an electrical generator, a waste heat recovery unit through which hot exhaust gases from the engine are passed to recover thermal energy in usable form, and means for conveying exhaust gases coming out of the waste heat recovering unit to a CO 2 recovery unit where the CO 2 is extracted and made available as a saleable byproduct.
Abstract: In accordance with an illustrative embodiment of the present invention, a cogeneration facility combined with means for producing CO 2 includes an internal combustion engine that drives an electrical generator, a waste heat recovery unit through which hot exhaust gases from the engine are passed to recover thermal energy in usable form, and means for conveying exhaust gases coming out of the waste heat recovery unit to a CO 2 recovery unit where the CO 2 is extracted and made available as a saleable byproduct.
90 citations
Patent•
28 Nov 1989
TL;DR: In this paper, a deactivating material is first applied to a substrate from the thin metal film in a pattern corresponding to the region from which heat is not to be generated, and the metal then is applied over the substrate and the pattern in a thickness which normally generates thermal energy upon exposure to microwave energy.
Abstract: A method is described for achieving selective generation of thermal energy from a thin metal film upon exposure to microwave energy. A deactivating material is first applied to a substrate from the thin metal film in a pattern corresponding to the region from which heat is not to be generated. The metal then is applied over the substrate and the pattern in a thickness which normally generates thermal energy upon exposure to microwave energy. Such thermal energy is produced only from those regions where the metal is adhered directly to the substrate.
84 citations
TL;DR: In this article, the authors presented a simplified procedure for evaluating the annual energy produced by a defined heliostate field, based on two continuous functions: annual energy per unit of mirror with its center placed at some point; and annual average density of mirror per unit area of level terrain (which defines the field) at the same point.
83 citations
Patent•
23 Mar 1989
TL;DR: In this paper, a solar energy collector is described for selectively collecting an electrical energy and a thermal energy at the same time from solar energy, using an inorganic and metal composite in the form of a roof tile or a wall-forming member.
Abstract: A solar energy collector device is disclosed for selectively collecting an electrical energy and a thermal energy at the same time from a solar energy The device comprises an inorganic-and-metal composite in the form of a roof tile or a wall-forming member which includes a solar battery exposed to sun rays and a heat medium passageway disposed underneath the battery The density of distribution of a particulate inorganic substance within a metal mass is varied through the areas of the tile or wall member so as to effectively collect the respective energies without adversely affecting the interior conditions of a building in which the device is installed
52 citations
Patent•
08 Sep 1989TL;DR: In this article, the authors propose an approach for cooling an electronic circuit module that includes a heat sink in thermal contact with the circuit module and a device for directing cooling gas at the heat sink.
Abstract: Apparatus for cooling an electronic circuit module includes a heat sink in thermal contact with the circuit module and a device for directing cooling gas at the heat sink. The heat sink includes multiple fins defining channels between them, a base having a surface for contact with the circuit module, and a plurality of passages located between the fins and the base and interconnecting with the channels. At least a part of the cooling gas flows between the fins and absorbs thermal energy from the fins and then flows through the passages and absorbs additional thermal energy. The fins and the passages provide a large area of contact with the cooling air and reduce the pressure drop through the heat sink. The heat sink provides a path for efficient conduction of thermal energy from the circuit module to the fins and prevents the formation in the cooling air of recirculating eddies which can reduce heat transfer.
47 citations
TL;DR: In this paper, a class of one-dimensional hyperbolic heat conduction problems involving non-Fourier effects is studied, where the thermal energy propagates with very sharp discontinuities at the wave front.
Abstract: The phenomenon of hyperbolic heat conduction in contrast to the classical (parabolic) form of Fourier heat conduction involves thermal energy transport that propagates only at finite speeds, as opposed to an infinite speed of thermal energy transport. To accommodate the finite speed of thermal wave propagation, a more precise form of heat flux law is involved, thereby modifying the heat flux originally postulated in the classical theory of heat conduction. As a consequence, for hyperbolic heat conduction problems, the thermal energy propagates with very sharp discontinuities at the wave front. Accurate solutions are found for a class of one-dimensional hyperbolic heat conduction problems involving non-Fourier effects that can be used effectively for representative benchmark tests and for validating alternate schemes. Modeling/analysis formulations via specially tailored hybrid computations are provided for accurately modeling the sharp discontinuities of the propagating thermal wave front. Comparative numerical test models are presented for various hyperbolic heat conduction models involving non-Fourier effects to demonstrate the present formulations.
45 citations
TL;DR: In this paper, the thermal performance of an uncovered radiator and a radiative cooling system was investigated experimentally and theoretically, and the experimental and analytical results agreed well with each other.
Abstract: The thermal performance of an uncovered radiator and a radiative cooling system was investigated experimentally and theoretically. The net radiative power of a black painted surface at ambient air temperature was measured by heat flux plates at night in order to use the results for predicting temperatures of the radiator surface and the fluid in the cooling system on the same night. The net radiative power obtained by the measurements was 40--60 W/m{sup 2} on clear nights in the summer and 60--80 W/m{sup 2} in the fall and winter. The average temperature of the energy storage tank on clear nights became 2--5{degrees}C below the ambient temperature. The experimental and analytical results agreed well with each other.
45 citations
TL;DR: In this paper, a three-phase equation-of-state model for high-pressure high-density simulations of systems containing carbon is described for the system graphite-diamond-liquid.
Abstract: A three-phase equation-of-state model, to be used in high-pressure high-density simulations of systems containing carbon, is described for the system graphite-diamond-liquid. The solid phases are represented by cold lattice and thermal energy terms. Simple additivity of the energy terms is assumed and the cold curve is a modified Birch form. Liquid states for diamond and graphite are obtained by a previously described scaling model. The actual Gibbs free energy of the liquid state uses the free energy of these liquids in a mixture model that includes an entropy of mixing and a pressure-dependent strain term. It is noted that the thermal expansion coefficient and the Gruneisen gamma increase faster above 3000 K than the usual approximation for the volume dependence would predict. The result is a phase diagram that fits all available data.
45 citations
TL;DR: In this paper, attempts of all kinds made before 1950 to produce mechanical energy from thermal solar power are reviewed chronologically, and the very many devices, rated up to 100 kW output, which have been developed since 1950 are reviewed.
TL;DR: In this article, the authors describe thermomagnetic heat engines that convert thermal energy into mechanical energy, and a computer model is developed from which the performance of the device can be determined.
Abstract: Thermomagnetic heat engines that convert thermal energy into mechanical energy are described. These heat engines utilize the thermomagnetic effect which is a property of ferromagnetic materials whereby their magnetization changes with temperature. A computer model is developed from which the performance of the device can be determined. Design curves are included which give the overall dimension, operating parameters, and thermal efficiency of thermomagnetic heat engines operating between a thermal source of 90, 150, or 225 °C and a thermal sink of 25 °C.
TL;DR: In this article, the basic methods of heating and cooling of buildings are: solar radiation, out-going longwave radiation, water evaporation, and nocturnal radiation cooling.
Patent•
16 Oct 1989
TL;DR: In this paper, a multi-stage system for high flux transformation of solar energy allowing for uniform solar intensification by a factor of 60,000 suns or more is described, which employs a focusing mirror as a primary concentrative device and a non-imaging concentrator as a secondary concentrator with concentrative capacities of primary and secondary stages.
Abstract: Disclosed are multi-stage systems for high flux transformation of solar energy allowing for uniform solar intensification by a factor of 60,000 suns or more. Preferred systems employ a focusing mirror as a primary concentrative device and a non-imaging concentrator as a secondary concentrative device with concentrative capacities of primary and secondary stages selected to provide for net solar flux intensification of greater than 2000 over 95 percent of the concentration area. Systems of the invention are readily applied as energy sources for laser pumping and in other photothermal energy utilization processes.
TL;DR: In this article, photoacoustics is used as a calorimetric method in conjunction with electrical measurements to determine which mechanisms are involved in the conversion of most of the absorbed radiation to thermal energy in (mainly Si pn) solar cells.
Abstract: Photoacoustics is used as a calorimetric method in conjunction with electrical measurements to determine which mechanisms are involved in the conversion of most of the absorbed radiation to thermal energy in (mainly Si p‐n) solar cells. The major mechanisms that are identified and quantified include local cooling, near the junction of the cells. Quantification is made possible by the use of a model for internal energy fluxes in a photovoltaic cell, which takes into account the different spatial distributions of heat generated by photogenerated and injected carriers. The experimental results agree well with calculations based on the model also in the case of thin‐film CdS/CuInSe2 cells.
TL;DR: The objective of extended thermodynamics of molecular ideal gases is the determination of the 17 fields of mass density, velocity, energy density, pressure deviator, heat flux, intrinsic energy density and intrinsic heat flux as discussed by the authors.
Abstract: The objective of extended thermodynamics of molecular ideal gases is the determination of the 17 fields ofmass density, velocity, energy density, pressure deviator, heat flux, intrinsic energy density and intrinsic heat flux.
Patent•
20 Apr 1989TL;DR: In this paper, a thermal heat transfer member for line replaceable module (LRM) was proposed for use in electronic or microwave systems with particular application to advanced avionic systems.
Abstract: A thermal heat transfer member is disclosed for use in electronic or microwave systems with particular application to advanced avionic systems. This thermal heat transfer member for line replaceable module (LRM) comprises; a bottom cover, a grid partition bottom means, a solid thermal plane material fixedly interconnected to the grid partition bottom means, a grid partition top means fixedly interconnected upon the thermal plane, sandwiching the thermal plane between the grid partition top and the grid partition bottom, and finally, a top cover. The utilization of a "building block" approach and composite high strength heat-conductive materials designed to dissipate heat away from electronic devices and components mounted within the LRM operate to produce a radio frequency LRM of high heat conductivity with reduced weight ideal for utilization in advanced development avionic systems subject to extreme G-force and stress in avionic system operation.
Patent•
02 Mar 1989
TL;DR: In this article, an auxiliary burner is used to provide supplemental thermal energy to a vehicle having a room and domestic water to be heated, where the auxiliary burner operates efficiently at a rated thermal output when it is operated for at least the duration of a minimum operational cycle.
Abstract: An auxiliary burner provides supplemental thermal energy to a vehicle having a room and domestic water to be heated. The auxiliary burner operates efficiently at a rated thermal output when it is operated for at least the duration of a minimum operational cycle. A reservoir contains heat transfer liquid having a selected thermal energy storage capacity, measured by the amount of thermal energy required to heat the liquid from a minimum to a maximum operating temperature. The heat transfer liquid receives heat from the auxiliary burner. The thermal energy storage capacity is selected so that the auxiliary burner must operate at its rated thermal output for at least the duration of the minimum desired operational cycle to provide the selected thermal energy storage capacity to the reservoir. Methods of the present invention include heating the reservoir containing the heat transfer liquid having the selected thermal energy storage capacity by operating the auxiliary burner at the rated thermal output for at least the duration of the minimum desired operational cycle. With the heat transfer liquid in the thermal reservoir at the maximum operating temperature and the auxiliary burner off, heat is transferred from the thermal reservoir to meet thermal demands for heated room air and domestic hot water. These demands decrease the temperature of the heat transfer liquid to the minimum operating temperature, whereupon the auxiliary burner is operated for at least the duration of the minimum desired operational cycle to raise the temperature of the heat transfer liquid to the maximum operating temperature.
TL;DR: In this paper, the balance between thermal and collective energies for heavy-ion collisions in the 20 −100 MeV/u bombarrding energy range was analyzed using the Landau-Vlasov equation.
TL;DR: A review of the contribution of radiative heat transfer in relation to the total heat transfer by employing different experimental techniques can be found in this article, where relative merits and demerits of these methods are discussed, and a critical appraisal of the different alternatives is given.
01 Aug 1989
TL;DR: In this paper, a computer program is developed to minimize the present worth of the electric and thermal energy costs of a manufacturing facility as a function of the type and amount of cogeneration and thermal storage it might install.
Abstract: A computer program has been developed to minimize the present worth of the electric and thermal energy costs of a manufacturing facility as a function of the type and amount of cogeneration and thermal storage it might install. The model is particularly useful in instances where the rates paid for electricity are differentiated by time of day and season. The program has been applied successfully to two large industrial facilities located in the southern United States. It simulates the optimal electricity production and thermal energy usage patterns as a function of the equipment installed in the plant over a planning horizon of 15 years, based upon a year's worth of historical data, projected load growth, and projected rates for fuel and electricity.
Patent•
23 Aug 1989
TL;DR: In this article, an electrical solid state device (ESD) is mounted on a circuit board (1) suspended from a relatively thick heat sink plate (3) by screws with spacer elements.
Abstract: An electrical solid state device (2) is mounted on a circuit board (1) suspended from a relatively thick heat sink plate (3) by screws with spacer elements (4). The heat sink plate is mechanically coupled to a heat dissipate element (9) with cooling fins to increase the effective area. The transmission of heat energy between the solid state device and the heat sink is provided by a hemispherical element (6) with a threaded insert (7) and an adaptor pad (12) to give good contact. A plain insert subjected to spring pressure may also be used. ADVANTAGE - Provides efficient transfer of thermal energy irrespective of type of mounting, i.e. whether surface or socket (pin grid array).
TL;DR: In this article, the gas-dynamic response of argon to fission-fragment energy deposition is simulated, for the first time explicitly including the coupling between the gas density, which is spatially and temporally varying, and the power density.
Abstract: The gas-dynamic response of argon to fission-fragment energy deposition is simulated, for the first time explicitly including the coupling between the gas density, which is spatially and temporally varying, and the power density. In simulations of three experiments with different initial fill pressures of argon, good agreement was found between calculated and observed pressure rises, after the experimental pressure rise data from one case were used as a calibration. However, in each case, the calculated thermal energy deposition corresponding to the experimental pressure data was about half the fission-fragment kinetic energy release into the gas predicted by neutron and fission-fragment transport calculations. Also, the experimental pressure data exhibited a decay not seen in the simulations, which did not incorporate an energy-loss mechanism.
TL;DR: In this paper, a constant flow calorimeter is described for the determination of the thermal energy generated during the electrolysis of D 2 O, using a Pd sheet electrode, which is that which would be expected from basic electrochemical principles.
TL;DR: In this paper, the theoretical performance characteristics of single stage heat transformers using various promising binary mixtures as working fluids have been discussed in the context of heat delivery temperature and the comparison of working fluids has also been discussed.
Abstract: A large amount of thermal energy, in the temperature range of 50–90°C, released to the atmosphere by many commercial installations such as agrofeed, paper mills, dairies and process industries, can be upgraded making possible its use in various forms. Many attempts have benn made in most industrial sectors to recovery this energy by heat pumps, organic Rankine cycles and heat transformers. Among various possibilities, heat transformers present an attractive solution as low level heat can be transformed into a higher temperature with minimum consumption of external energy. Further transformers do not require high maintenance and operating cost. The theoretical performance characteristics of single stage heat transformers using various promising binary mixtures as working fluids have been discussed in this paper. The coefficient of performance, energy efficiencies and mass circulation ratio have been analysed as a function of heat delivery temperature. The comparison of working fluids has also been discussed.
TL;DR: In this article, a statistical model with complete equipartition among fragmentation and internal excitation degrees of freedom, but not with respect to the fragment's kinetic energy, is proposed, and the resulting internal temperature is very insensitive to the initial total energy in agreement with experiment.
TL;DR: In this article, the static behavior of the solar thermal storage is studied and it is shown that during the thermal diffusion period, the extraction efficiency decreased primarily due to thermal losses to the environment and thermal degradation caused by the storage tank walls.
Abstract: The thermal storage is a key component of any successful solar thermal system. A good thermal storage should allow minimum thermal energy losses while permitting the highest possible extraction efficiency of the stored thermal energy. Despite the many available examples of successful designs of solar thermal storage tanks, the static behavior of the solar thermal storage is not fully understood. Among the many factors influencing such behavior are heat losses, tank geometry, dead zones, and tank wall material. In this study laboratory-scale models with different geometries were built for the purpose of examining thermal behavior during the period after charging. During this period, called the thermal diffusion period, the extraction efficiency was temporarily decreased until natural stratification was achieved. After the thermal diffusion period, the extraction efficiency decreased primarily as a result of thermal losses to the environment and thermal degradation caused by the storage tank walls....
Patent•
23 Mar 1989
TL;DR: In this article, the authors employ fluids which include non-aqueous and relatively non-volatile components as permanent and reusable microwave susceptors, effectively contained for their intended heating functions, convert microwave energy into thermal energy which is stored in the fluids and their containers.
Abstract: The methods of this invention employ fluids which include non-aqueous and relatively non-volatile components as permanent and reusable microwave susceptors. The fluids, effectively contained for their intended heating functions, convert microwave energy into thermal energy which is stored in the fluids and their containers. The stored energy is utilized for the purpose of heating a load object.
TL;DR: A survey by Wood et al. as discussed by the authors revealed that a wide spectrum of opportunities exists for employing thermal energy storage systems in industrial applications, including industrial, residential, and commercial scale applications.
Abstract: Economies in the design and operation of energy conversion systems often result if some provision is made for the storage of thermal energy. Such provisions must be included in an energy conversion system when the supply of and demand for thermal energy do not coincide in time. A survey by Wood, et al [1] has revealed that a wide spectrum of opportunities exists for employing thermal energy storage systems in industrial applications. Detailed descriptions of thermal energy storage systems for industrial-, residential-, and commercial- scale applications appear elsewhere [2,3] and will not be discussed here.