scispace - formally typeset
Search or ask a question

Showing papers on "Thermal energy published in 1985"


Patent
14 Jun 1985
TL;DR: In this paper, a heat pipe system comprising an assembly of two tubes in concentric relation, the inner tube being constituted by a relatively small diameter capillary for the return of working fluid to the vicinity of the relatively hot strata.
Abstract: Geothermal energy is recovered from an underground zone of relatively hot strata via a borehole into which is inserted a heat pipe system containing a working fluid, the heat pipe system comprising an assembly of two tubes in concentric relation, the inner tube being constituted by a relatively small diameter capillary for the return of working fluid to the vicinity of the zone of the relatively hot strata. The working fluid is preferably assisted in its return under gravity by means of a pump. The system includes heat exchange means operable to recover thermal energy from the working fluid. A third and outermost tube may be used to reduce heat losses, this third tube enclosing the two tubes over all but that part of their length which is in the zone of relatively hot strata.

247 citations


Journal ArticleDOI
TL;DR: In this paper, thermal coupling and etch rate measurements were reported for polyethylene terephthalate and polyimide films irradiated at excimer laser wavelengths of 193, 248, and 308 nm.
Abstract: Thermal coupling and etch rate measurements are reported for polyethylene terephthalate and polyimide films irradiated at excimer laser wavelengths of 193, 248, and 308 nm. Thermal energy balance is observed up to a threshold fluence but above this the energy absorbed remains approximately constant, the excess energy being carried away by the ablated material. The ablated material appears to have a temperature >103 K as determined by calculations based on the thermal energy loading and relaxation time estimated from IR measurements. These results provided useful information on the interaction mechanism.

196 citations


Journal ArticleDOI
M. Mahalingam1
01 Sep 1985
TL;DR: In this paper, thermal management at device level packaging involves efficient and cost-effective removal of dissipated thermal energy from the device to assure its reliable performance over the long term, which will mean making such devices possible close to the natural limits set by thermal physics.
Abstract: Thermal management at device level packaging involves efficient and cost-effective removal of dissipated thermal energy from the device to assure its reliable performance over the long term. In the context of very high levels of integration of future ICs, thermal management will mean making such devices possible close to the natural limits set by thermal physics. This paper will present trends in important parameters and discuss solutions through examples.

116 citations


Patent
13 Dec 1985
TL;DR: In this article, a new and unique underground heat exchanging apparatus of the type including a first heat insulating tube and a second heat exchangeable tube connected to the former at the lower end of the latter is presented.
Abstract: A new and unique underground heat exchanging apparatus of the type including a first heat insulating tube and a second heat exchangeable tube connected to the former at the lower end of the latter Both the first and second tubes are inserted downwardly into a deep hole drilled in the ground The apparatus is operated by utilizing the excellent heat conservation and the huge heat capacity inherent to the underground The first tube is located at the center of the hole and the second tube extends about the first tube in a spiral configuration A liquified gas is introduced into both the first and second tubes Heat exchanging is achieved between the second tube and the surrounding underground To recirculate the liquified gas through the tubing system a heat exchanging unit including compressor and an expansion valve or the like is mounted on the ground surface When the apparatus is used in a heating cycle, thermal energy is transferred from the underground to the second tube On the other hand, when the apparatus is in a cooling system, heat is transferred from the second tube to the underground

107 citations


Journal ArticleDOI
TL;DR: In this paper, the equilibrium properties of superstring theories at high densities are discussed and it is argued that the ideal gas approximation is good for both type I and type II theories.

86 citations


Journal ArticleDOI
TL;DR: In this paper, a new model was developed for the transient thermal response of a packed bed, using the method of spatial averaging, and it was found that after a sufficiently long time has elapsed, the temperature pulses for the fluid and solid phases will be separated by a constant distance and will spread or disperse about their centroids at an equal rate.
Abstract: A new model is developed for the transient thermal response of a packed bed, using the method of spatial averaging. Equations for the average temperature of the fluid and the solid phase are derived from the point equations for thermal energy in each phase. The new model exhibits some unusual convective and dispersive coupling between the equations for the average fluid and solid temperatures. The response of the model equations to a pulse disturbance is analyzed. It is found that after a sufficiently long time has elapsed, the temperature pulses for the fluid and solid phases will be separated by a constant distance and will spread or disperse about their centroids at an equal rate. The pulse separation predicted by the new model equations is larger than that predicted using more conventional analyses of heat transfer in packed beds. Effective thermal conductivities measured under steady state conditions can differ significantly from those observed in transient experiments due to the spread in temperature pulses caused by heat exchange between phases. Estimates are made of the magnitude of the more important terms affecting longitudinal and lateral effective thermal conductivities under flow conditions, in order to make possible a direct comparison between theory and experiment in a companion paper.

68 citations


Patent
07 Aug 1985
TL;DR: In this paper, a bulk thermal energy storage device is provided comprising a bulk storage tank containing a latent energy storage material, preferably a phase change material which is subject to repeated melting and freezing during which latent thermal energy is absorbed or released.
Abstract: A bulk thermal energy storage device is provided comprising a bulk storage tank containing a latent energy storage material, preferably a phase change material which is subject to repeated melting and freezing during which latent thermal energy is absorbed or released by the phase change material. A plurality of heat exchange devices are generally vertically positioned within the phase change material and at a predetermined distance from each other and from the walls of the storage tank for flow of a heat exchange fluid serially through said passageways in the heat exchange devices. At least one screen is positioned in the storage tank in a generally horizontal position and extending between the walls of the tank and the heat exchange devices for supporting the phase change material when in a frozen condition during the melting cycle of the phase change material to prevent settling of the phase change material to the bottom of the tank. The predetermined positioning of the heat exchange devices and the screen in the storage tank provide for an optimum heat exchange between the heat exchange devices and the phase change material in the tank and prevent the loss of heat exchange efficiency due to a settling-out of frozen particles of the phase change material to the bottom of the tank.

64 citations


Journal ArticleDOI
TL;DR: In this paper, heat flow maps are classified by four different horizontal scales of 10 n km (n = 1, 2, 3 and 4) and attention is focussed on the interpretation of anomalies which appear with characteristic dimensions of 10 (n − 1) km in the respective representations.

57 citations


Journal ArticleDOI
TL;DR: In this paper, gas breakdown in electronegative gases and short non-uniform field gap is studied with a set of equations taking into account the spatio-temporal changes of the conductivity along the discharge axis and the variation of the neutral species density due to hydrodynamic processes.
Abstract: Gas breakdown in electronegative gases and short non-uniform field gap is studied with a set of equations taking into account the spatio-temporal changes of the conductivity along the discharge axis and the variation of the neutral species density due to hydrodynamic processes. This simulation from a precise configuration to a general conclusion shows how the spark formation is controlled by electron energy dissipation, and in particularly the fraction of this energy which dissipates as thermal energy and by the attachment process via the field redistribution.

54 citations


Journal ArticleDOI
TL;DR: In this paper, a small seawater solar desalination plant has been designed and constructed as part of a cooperative research program for solar Desalination between the Water and Electricity Department (Abu Dhabi) and the New Energy Development Organisation (Japan).

40 citations


Patent
31 May 1985
TL;DR: In this paper, a method of flame spraying particulate material utilizing the thermal energy of a very hot gaseous primary stream produced in an oxy-fuel combustion chamber combined with kinetic energy from a surrounding annular sheath of warm high velocity secondary air is described.
Abstract: Disclosed is a method of, and apparatus for, flame spraying particulate material utilizing the thermal energy of a very hot gaseous primary stream produced in an oxy-fuel combustion chamber combined with kinetic energy from a surrounding annular sheath of warm high velocity secondary air.

Journal ArticleDOI
S. Suda1
TL;DR: In this paper, the present status of the Japanese developments of the metal-hydride energy conversion systems is described, and the metal hydride reactions applied for cyclic uses are correlated in connection with various hydrides properties, operating modes, and cost-effectiveness standpoints.

Journal ArticleDOI
TL;DR: In this paper, the authors studied the effects of ejector-compression systems on the mass flow ratio of motive vapour to evaporator vapour, condenser heat capacity and coefficient of performance.

Patent
23 Jan 1985
TL;DR: In this article, the authors describe various heat cycles which make use of comparatively low grade heat such as that from hot rock geo-thermal sources, the cycles incorporating either a helical screw expander or a rotary vane expander operating with an organic working fluid.
Abstract: Various heat cycles which make use of comparatively low grade heat such as that from hot rock geo-thermal sources, the cycles incorporating either a helical screw expander or a rotary vane expander operating with an organic working fluid and in accordance with the invention, the exhaust from the helical screw expander or rotary vane expander is used in a conventional rankine cycle.

Patent
15 Nov 1985
TL;DR: In this article, a dual-fueled thermoelectric generator with two different sources of energy are provided, one from an overhead transmission ground wire (72) and the other from electric resistance heaters (21).
Abstract: A dual fueled thermoelectric generator wherein two different sources of energy are provided. The first source (23) of energy is electrical energy which is tapped from an overhead transmission ground wire (72) and converted into thermal energy by electric resistance heaters (21). The thermal energy produced is applied to a thermopile (22) which converts it into DC electric energy. The second source (14) is a fossil fuel which is converted into thermal energy when a burner (30) is actuated. The thermal energy produced thereby is applied to thermopile (22). The burner (30) is actuated in response to either a loss of input voltage from the transmission ground wire (72) or loss of output power from the thermopile (22)

Patent
15 Jul 1985
TL;DR: In this article, an apparatus is described for generating thermal and electrical energy outputs in response to thermal and electric load requirements imposed thereon, including a variable speed power source and a mechanism for transferring thermal energy from the power source a coolant fluid.
Abstract: An apparatus is disclosed for generating thermal and electrical energy outputs in response to thermal and electrical load requirements imposed thereon. The apparatus includes a variable speed power source and a mechanism for transferring thermal energy from the power source a coolant fluid. A generator is also provided and is driven by the power source to produce electrical energy for the electrical load. The output frequency of the generator is independent of the speed of the power source. A mechanism is also provided for extracting thermal energy from the coolant fluid and directing the thermal energy to the thermal load. Finally, a device is included for monitoring the loads and controlling the thermal and electrical outputs in response to the loads by independently varying the speed of the power source and the output frequency of the generator to provided desired thermal and electrical energy outputs.

Book Chapter
01 Jan 1985
TL;DR: The classical theory of vaporization and combustion of fuel droplets is examined for low Reynolds numbers, when the effects of the motion of the droplet relative to the ambient atmosphere can be neglected, and the process can be considered spherico-symmetrical as discussed by the authors.
Abstract: The classical theory of vaporization and combustion of fuel droplets is examined for low Reynolds numbers, when the effects of the motion of the droplet relative to the ambient atmosphere can be neglected, and the process can be considered spherico-symmetrical. The large value of the ratio of the liquid density the ty-pical gas density justifies the quasi-steady approximation in the analysis of the gas phase process. The large value of the ratio of the heat of vaporization per unit mass of fuel to the typical specific thermal energy of the liquid results in the existence of a first stage of droplet heat-ing without vaporization, and a second stage when vaporizarion occurs at a nearly constant web-bulb temperature, close to the boiling temperature. The large values of typical activation energies of the gas phase reactions, leads to the possibility of multiple solutions of the quasi-steady conservation equations for the gas phase. These include solutions corresponding to a nearly frozen mode of vaporization, that can not exist above an "ignition" value of the ambient temperature, and a mode of vaporization with diffusion controlled combustion that can not exist for ambient temperatures below an "extinction" value.

01 Sep 1985
TL;DR: The thermal energy used was found to be 23,957 GWh, in most instances above a reference temperature of 35 to 40C as mentioned in this paper, and the amount of oil saved by geothermal energy direct uses worldwide was estimated to be about 2.8 million tons per year.
Abstract: District heating is the largest sector of geothermal energy direct use in the world. It holds great promise for further development, especially when operated in conjunction with district cooling. At the end of 1984, the installed thermal power of all direct use projects in the world was about 7072 MW and the associated flow rate, 57,803 kg/s. The thermal energy used was found to be 23,957 GWh, in most instances above a reference temperature of 35 to 40C. The amount of oil saved by geothermal energy direct uses worldwide was estimated to be about 2.8 million tons per year.

Patent
09 May 1985
TL;DR: In this article, a method and system for sensing explosive fires by the parallel processing of signals derived from both electromagnetic radiation and mechanical wave energy simultaneously emanating from or near the source of these fires is described.
Abstract: Described herein is a method and system for sensing explosive fires by the parallel processing of signals derived from both electromagnetic radiation and mechanical wave energy simultaneously emanating from or near the source of these fires. The electromagnetic radiation or thermal energy is detected by an electromagnetic wave energy detector or a thermal detector (1 to 6) and the mechanical wave energy is detected by a pressure transducer (1 to 8). This diverse-stimuli sensing capability enhances force alarm immunity of the system.

Journal ArticleDOI
TL;DR: In this article, a solar absorption cooling system and its performance for an office building having an occupancy of 7 h per day was described, where the absorption system of 40 RT cooling capacity (installed) uses 300 m 2 of flat plate collector area and an oil-fired supplementary thermal energy source.
Abstract: This paper describes a solar absorption cooling system and its performance for an office building having an occupancy of 7 h per day. The absorption system of 40 RT cooling capacity (installed) uses 300 m 2 of flat plate collector area and an oil-fired supplementary thermal energy source. The system produces > 10 000 kWh cooling per month. Considering the parasitic electric energy needs and the electrical energy equivalent of make-up water consumed in the energy rejection subsystem, the solar cooling installation saves 25–40% per day of electrical energy when compared to an equivalent cooling capacity conventional cooling system.

Patent
16 Jul 1985
TL;DR: An optimized unitary energetic system for an internal combustion engine comprising a gas distribution system for intake and exhaust associated with an optimized variable geometry combustion chamber with a regenerative cylinder wall lining to contain thermal energy is presented in this article.
Abstract: An optimized unitary energetic system for an internal combustion engine comprising a gas distribution system for intake and exhaust associated with an optimized variable geometry combustion chamber with a regenerative cylinder wall lining to contain thermal energy and a microprocessor to correlate certain factors and control the gas distribution system and combustion chamber geometry for optimization of engine operation.

Patent
20 Sep 1985
TL;DR: A heat recovery unit as mentioned in this paper is used in association with a fluid distribution system including: a heat exchanger; means to: circulate fluid through the system and to introduce fresh fluid across one end of the system for mixing with the circulating fluid; ventilate a portion of the circulating fluids across the other end to transfer the thermal energy between the ventilated fluid and fresh fluid so as to replenish said ventilated fluids with said fresh fluid.
Abstract: A heat recovery unit for use in association with a fluid distribution system including: a heat exchanger; means to: circulate fluid through said system and to introduce fresh fluid across one end of said heat exchanger and into said system for mixing with the circulating fluid; ventilate a portion of the circulating fluid across the other end of said heat exchanger to transfer the thermal energy between said ventilated fluid and said fresh fluid so as to replenish said ventilated fluid with said fresh fluid.

Journal ArticleDOI
TL;DR: The calculation of composite curves for a complex process gives valuable information related to energy requirements and temperature bottlenecks and an interactive computer program for heat pump analysis related to complex thermal processes is employed as the analytic tool.

Journal ArticleDOI
TL;DR: In this article, the authors used a solution of the two-dimensional diffusion equation for a composite slab subjected to a sudden change in environment and showed that the interaction between the collectors, store and load is more critical in this system than in a conventional active solar-heating system.

Patent
04 Jul 1985
TL;DR: In this paper, the authors proposed to increase the temperature difference between the high temperature side and the low temperature side of a thermoelectric generator to enhance the energy conversion efficiency.
Abstract: PURPOSE:To enhance the energy conversion efficiency by increasing the temperature difference between the high temperature side and the low temperature side of a thermoelectric generator. CONSTITUTION:A thermoelectric generator 4 is disposed at a low temperature side compartment 3, and coupled with a high temperature side compartment 2 by a heat pipe 5 which passes a partition plate 1. The low temperature side of the pipe 5 is connected with the high temperature unit 6 of the generator, and thermal energy is transferred from the compartment 2 through the pipe 5 efficiently to the unit 6 at a high speed. On the other hand, the high temperature side of a heat pipe 7 filled with low temperature medium is connected with the low temperature unit 8 of the generator in the compartment 3 to air cool the low temperature side of the pipe 7. The pipe 7 efficiently transfers the thermal energy even at the low temperature unit by using the medium.


Journal ArticleDOI
TL;DR: In this article, it was shown that the interlinking is dominated by stimulated natural joints and the degree of normal dilation that can be achieved is limited by the orientation of the natural discontinuity with the pre-existing stresses and hence the shear stress on the joint.
Abstract: The term hot dry rock (HDR) has been used to describe the exploitation of the thermal energy contained in rocks that have a sufficiently high temperature but contain insufficient fluids to enable the heat to be extracted. The attraction of such a resource is that it is probably available everywhere, but at varying depths. International activity has focused on the problem of circulating fluids through the rock and extracting the heat by conduction from the rock to the fluid. The initial concepts were based on creating individual cracks to interlink two wells approximately 500 m apart. The necessary heat exchange area was to be achieved by using multiple systems of interconnections in parallel. The results from the field work have shown that the interlinking is dominated by stimulated natural joints and the degree of normal dilation that can be achieved is limited by the orientation of the natural discontinuity with the pre-existing stresses and, hence, the shear stress on the joint. The normal dilation is important because it controls the resistance to flow between the wells. The shear mechanism controls the far-field water losses and the direction of growth of the more permeable interwell region and has obvious implications for the proposed geometry of any system. The cost of drilling has been shown to be comparable to deep drilling for other purposes and the development of deviated holes in strong crystalline rocks has been shown to be possible. The progress of the stimulation has been mapped successfully by locating the microseismic events generated by shearing but the relationship of the microseismically active areas and the heat transfer region has yet to be identified. No adverse environmental problems have been identified; the produced fluids are generally benign and the microseismicity is well below any threshold of damage. The goal of a universally available heat source free of stack emissions and waste products that does not consume finite reserves of minerals and hydrocarbon demands substantial investment in the research to determine if it is attainable. The major field programmes should have reached their preliminary conclusions by the middle of 1986.

Journal ArticleDOI
TL;DR: In this paper, a self-consistent time dependent Thomas-Fermi model at finite temperature was used to calculate the dynamical evolution of hot and compressed nuclei, and it was found that nuclei can accomodate more thermal energy than compressional energy before they break.
Abstract: We have used a self-consistent time dependent Thomas-Fermi model at finite temperature to calculate the dynamical evolution of hot and compressed nuclei. It has been found that nuclei can accomodate more thermal energy than compressional energy before they break.

Journal ArticleDOI
TL;DR: In this paper, the authors discuss the application of the downhole heat exchanger for space heating using examples from New Zealand and Klamath Falls systems, and report a recent study on the parameters necessary to achieve an optimum design.

Journal ArticleDOI
TL;DR: In this article, the second derivative of the V-i curve which is necessary to get the energy distribution function was obtained by means of the second harmonic method, and the second derivatives obtained at lower ionosphere (90-150Km) showed clear peaks at the energies which correspond to the wave length of excited gas emissions.
Abstract: Energy distribution of low energy (0.2-2.5eV) electrons was measured by means of Langmuir probe at eleven o'clock J. S. T. on the 13th, February, 1982 over Kagoshima Space Center, Japan. Second derivative of the V-i curve which is necessary to get the energy distribution function was obtained by means of the second harmonic method. The second derivatives obtained at lower ionosphere (90-150Km) showed clear peaks at the energies which correspond to the wave length of excited gas emissions. Some of these peaks were identified as due to O and O2. The results conclusively suggest that electrons of thermal energy range interact with ambient excited neutral (and/or ionized) gases and gain energy from them.