Showing papers on "Thermal energy published in 1980"

Whole planet cooling and the radiogenic heat source contents of the Earth and Moon

Abstract: It is widely believed that the surface heat flows of the earth and moon provide good measures of the total amounts of radioactives in these bodies. Simple thermal evolution models, based on subsolidus whole mantle convection, indicate that this may not be the case. These models have been constructed assuming an initially hot state, but with a wide variety of choices for the parameters characterizing the rheology and convective vigor. All models are constrained to be consistent with present-day surface heat fluxes, and many of the terrestrial models are consistent with the mantle viscosities indicated by post-glacial rebound. For the earth the acceptable models give a radiogenic heat production that is only 65–85% of the surface heat output, the difference being due to secular cooling of the earth (about 50°–100°C per 10^9 years in the upper mantle). It is argued that the actual heat generation may be substantially less, since the models omit core heat, upward migration of heat sources, possible layering of the mantle, and deviations from steady convection. Geochemical models which are near to chondritic (apart from potassium depletion) are marginally consistent with surface heat flow. In the lunar models, heat generation is typically only 70–80% of the surface heat flow, even with allowance for the strong near-surface enhancement of radioactives. Despite the simplicity of the models the persistence of a significant difference between heat generation and heat output for a wide range of parameter choices indicates that this difference is real and should be incorporated in geochemical modeling of the planets.

The Thermodynamics of Aqueous Water Electrolysis

Abstract: Precise definitions are given of three thermodynamic parameters which characterize the water‐electrolysis reaction: the enthalpic voltage, the higher‐heating‐value voltage, and the thermoneutral voltage. Expressions are derived for these parameters and for the reversible potential, as functions of temperature between 25° and 250°C, and of pressure between 1 and 100 atm. Heat losses due to radiation, convection, and conduction are also considered, and a thermal‐balance voltage is defined; representative values are calculated. Electrical‐energy efficiency is related to the characteristic parameters, and thermodynamic limitations on its value are discussed.

Passive cooling system

Abstract: A cold bank tank in an enclosure for storing thermal energy in a very small area contains a liquid heat transfer fluid and has a top which is the top of the enclosure and a spaced opposite bottom. An inside heat exchanger extends from the bottom of the tank in the enclosure for cooling warm air in the enclosure rising by natural convection, returning the cooled air to the enclosure and transferring the warm air to the tank wherein it warms the fluid in the tank. An outside heat exchanger outside the enclosure is spaced from the top of the enclosure and coupled to the tank. A plurality of energy storage rods in the fluid in the tank store thermal energy in a very small area. The heat warming the fluid is transferred to the energy storage rods and when the outside temperature decreases below a predetermined magnitude, heat is released from the rods to the liquid fluid and vaporizes the fluid. The vaporized fluid flows upward through piping to the outside horizontal heat exchanger, through the outside heat exchanger, whence its heat is dissipated in the cooler outside air, and the vapor is recondensed and returns by gravity force to the tank via piping thereby storing cold energy in the rods for release when the air in the enclosure is next warmed.

Thermal solar energy collector

Abstract: This invention contemplates a solar to thermal energy converter comprising spaced apart light polarizing materials defining a conduit therebetween for the passage of a fluid to be heated, the polarizing materials being positioned with respect to each other, whereby the amount of solar energy transmitted through the collector and hence absorbed by the fluid is controlled Optionally and preferably, at least one of the light polarizing materials is moveable so that the axis of absorption of the polarizing materials can be adjusted with respect to each other and in reference to collector temperature so that a predetermined amount of light will be transmitted through the device, thereby controlling the temperature within the collector

Combined Photovoltaic and Thermal Hybrid Collector

Abstract: Hybrid collector which produces both electric and thermal energy is very effective system for heightening efficiency of solar energy collector. In order to obtain the fundamental characteristics of these systems, two liquid type flat plate thermal collectors with selective surface have been modified by attaching 3'' diameter silicon solar cells. The measured cell array efficiencies were 8.84% and 9.20% at 28°C, AM 1.15. The maximum thermal efficiencies of these hybrid systems were 72% and 77% using water as coolant.

Energy conversion system.

Abstract: A thermal-mechanical energy converting device with at least two rotatably supported wheels and with one or more endless transmission elements (18) of a material having a memory effect capable in the bending mode of converting thermal energy into mechanical energy when heated from a temperature to a temperature above to transition temperature; the transmission elements (18) serve to drive one wheel (11) from the other wheel (15) upon application of thermal energy to the transmission elements (18), whereby the thermal energy is transferred from the other wheel (15) to the transmission elements (18) over at least a major portion of the circumferential contact of the transmission elements (18) with the other wheel (15).

Sunlight-into-energy conversion apparatus

Abstract: The present application discloses a sunlight-into-energy conversion apparatus in which at least one amorphous silicon solar cell having a thickness thin enough to permit the sunlight to pass therethrough is formed on the surface of a heat collecting plate attached to a heating medium tube in a thermal conductive manner, thereby permitting the sunlight to be effectively converted into thermal energy and electrical energy. When a plurality of such amorphous silicon solar cells are formed on the surface of the heat collecting plate through insulating films, respectively and connected in series to each other, high electromotive force may be obtained.

Current status and performance of the argonne Hycsos chemical heat pump system

Abstract: The Argonne hydrogen conversion and storage system (HYCSOS), under development since 1975, is a two-hydride concept which operates as a chemical heat pump for the storage and recovery of thermal energy for heating, cooling and energy conversion. The system, designed and constructed to show the scientific feasibility of the concept and to evaluate system components and materials for use as hydrides, has been operational for several years. Hardware for the operation of the system under computer program control is complete and routines for data handling and analysis are available. Transient thermal and effectiveness measurements on the current coiled-tubing heat exchangers were made and will be compared with those for an advanced concept tubular heat exchanger with alloy-loaded aluminum foam for heat transfer enhancement. Recent developments of alloy materials and their use in chemical heat pumps will be discussed.

Radiation energy collection and tracking apparatus

Abstract: A light energy collection apparatus comprising an optical system for collecting the light energy, a framework for supporting the optical system, a tracking device for driving the supporting framework so as to normally keep the optical system pointed at a light source, an optically transparent housing enclosing the optical system and the tracking device as well, a structure for supporting the housing and if required a means for converting the collected light energy into electrical or thermal energy.

Ground-storage of heat such as solar heat

Abstract: A method of storing thermal energy in a body which is in direct thermal contact with the surrounding earth. The energy is transferred to said ground body from heat absorbing devices, specifically solar heat absorbing devices, by circulating a liquid in a circuit incorporating a plurality of channels in the ground body and said heat absorbing devices. The thermal energy stored in the ground body is removed therefrom by means of the circulating liquid and used to control the heat of an object such as a building by circulating the heated liquid around the building in a further circuit incorporating further channels and heat emitting devices. The channels in the ground body are arranged and sized in accordance with the calculated amount of thermal energy supplied to and taken out of the ground body period such as one year. A defined surface surrounding the ground body is established at a distance from the most remote of the channels in a direction outwardly of the ground body so to reach a maximum temperature on the order of 35° C. and a temperature variation during the period of energy input and output of not more than 10° C.

Heat pump apparatus

Abstract: A heat pump apparatus including a compact arrangement of individual tubular reactors containing hydride-dehydride beds in opposite end sections, each pair of beds in each reactor being operable by sequential and coordinated treatment with a plurality of heat transfer fluids in a plurality of processing stages, and first and second valves located adjacent the reactor end sections with rotatable members having multiple ports and associated portions for separating the hydride beds at each of the end sections into groups and for simultaneously directing a plurality of heat transfer fluids to the different groups. As heat is being generated by a group of beds, others are being regenerated so that heat is continuously available for space heating. As each of the processing stages is completed for a hydride bed or group of beds, each valve member is rotated causing the heat transfer fluid for the heat processing stage to be directed to that bed or group of beds. Each of the end sections are arranged to form a closed perimeter and the valve member may be rotated repeatedly about the perimeter to provide a continuous operation. Both valves are driven by a common motor to provide a coordinated treatment of beds in the same reactors. The heat pump apparatus is particularly suitable for the utilization of thermal energy supplied by solar collectors and concentrators but may be used with any source of heat, including a source of low-grade heat.

Energy conversion and storage process

Abstract: An energy conversion process for converting thermal energy into stored electrochemical energy and then into electrical energy comprising heating a first FeCl2 -containing electrolyte melt to produce gaseous FeCl3 and a reductant product in a first chemical reaction, these reaction products being separated, cooled, optionally stored, and combined in a second FeCl2 -containing electrolyte melt to cause a reaction to take place which is the reverse of said first reaction, thereby regenerating said first melt and producing heat and electrical energy.

The Role of the Ceramic Heat Exchanger in Energy and Resource Conservation

Abstract: Current development activities in the field of ceramic heat exchangers for gas turbine applications are discussed, and it is projected that the encouraging results from these programs will stimulate a broader interest in high-temperature waste heat energy recovery. The future role the ceramic heat exchanger will play in energy recovery for different industrial applications is emphasized, and appropriate heat exchanger design criteria, types of construction, surface geometries, and development activities are briefly discussed. Paper No. 79-GT-106.

High power cooler and method thereof

Abstract: A high power cooler for absorbing heat from a high power source such as electronic components is especially applicable to airborne missiles wherein a cold plate is not available and the thermal energy produced by the high power source must be totally absorbed by the high power cooler. The cooler utilizes a reflux boiler for rapid assimilation of heat from the high power source and a condenser comprised of a plurality of honeycomb cells containing a heat of fusion coolant such as beeswax for absorbing heat from the vapors produced in the boiler causing the wax to melt and the vapors to return to the liquid state.

Geothermal pump down-hole energy regeneration system

Abstract: Geothermal deep well energy extraction apparatus is provided of the general kind in which solute-bearing hot water is pumped to the earth's surface from a subterranean location by utilizing thermal energy extracted from the hot water for operating a turbine motor for driving an electrical power generator at the earth 3 s surface, the solute bearing water being returned into the earth by a reinjection well. Efficiency of operation of the total system is increased by an arrangement of coaxial conduits for greatly reducing the flow of heat from the rising brine into the rising exhaust of the down-well turbine motor.

Analysis of energy utilization in spinach processing

Abstract: The equipment and methods used to monitor the electrical and thermal energy consumed in various unit operations in a spinach processing plant are described and the results of a processing plant energy audit are presented. It is concluded that it requires 6.5 MJ of natural gas and fuel oil and 0.072 MJ of electric power to process one kg of new spinach; the energy intensive operations in spinach processing are associated with exhaust boxes, blanchers, and retorts; uniform product flow through the canning line is essential to energy conservation; and design improvements are needed for the blancher, exhaust box, and retort. (LCL)

Thermal energy transport in the Venus ionosphere: Classical and saturated electron temperature profiles

Abstract: The classical equation for electron thermal conductivity, which gives a heat flux proportional to the temperature gradient, breaks down in regions of the Venus ionosphere where the temperature scale height becomes comparable to or less than the electron mean free path. Assuming that the actual flux is approximately given by the harmonic mean of the classical and the free molecular flow heat flux, we calculate model temperature profiles based on the Pioneer Venus data. We find that the high dayside and nightside temperatures can be maintained, in the absence of a magnetic field, with somewhat lower heat inputs than those suggested by previous investigators who also neglected the magnetic field. The required heat influx on the nightside is only about one fourth that on the dayside, in sharp contrast to the results of earlier calculations.

Heat balance in FCC process

Abstract: In a fluid catalytic cracking (FCC) process and apparatus, the heat balance between the reactor and the regenerator of the FCC operation is partially uncoupled by transferring at least a portion of thermal energy from the reactor vessel riser to the regenerator vessel. The transfer of thermal energy results in a higher regenerating temperature. The thermal energy is recirculated to the bottom section of the reaction riser through a regenerated catalyst having higher temperature. Consequently, the outlet of the reaction vessel is maintained at a substantially constant temperature (e.g., 100° F.) and the rate of conversion of the oil feed and the octane number of gasoline produced in the process are increased.

Two-phase thermal energy conversion system

Abstract: A two-phase thermal energy conversion system employs an evaporable liquid such as water, and a gas which is not liquefiable within the operating temperature and pressure ranges, such as air. The water and air are mixed and one of the two or both are heated so that the water evaporates and is absorbed by the air to result in a pressure increase. The increase of pressure or volume can be converted into mechanical energy by a prime mover such as a turbine or reciprocating piston engine. The heat of condensation is utilized and converted into mechanical power while the temperature and pressure are reduced. The liquid, such as water, may be below its boiling point. If the water consists of salt water, fresh water is derived as a condensation product from the prime mover.

Developing and upgrading of solar system thermal energy storage simulation models

Abstract: Two water tank component simulation models have been selected and upgraded. These models are called the CSU Model and the Extended SOLSYS Model. The models have been standardized and links have been provided for operation in the TRNSYS simulation program. The models are described in analytical terms as well as in computer code. Specific water tank tests were performed for the purpose of model validation. Agreement between model data and test data is excellent. A description of the limitations has also been included. Streamlining results and criteria for the reduction of computer time have also been shown for both water tank computer models. Computer codes for the models and instructions for operating these models in TRNSYS have also been included, making the models readily available for DOE and industry use. Rock bed component simulation models have been reviewed and a model selected and upgraded. This model is a logical extension of the Mumma-Marvin model. Specific rock bed tests have been performed for the purpose of validation. Data have been reviewed for consistency. Details of the test results concerned with rock characteristics and pressure drop through the bed have been explored and are reported.

Solar energy conversion apparatus provided with an automatic cut-in heat-supplying standby apparatus

Abstract: An improved solar energy conversion apparatus for effectively converting solar radiation thermal energy, on a high-efficiency basis, into captive stored thermal energy in a captive working medium in a closed-cycle power conversion system (usually consisting of flow-path-defining apparatus such as piping, tubing or the like) and adapted at an output end to be connected to any of various different types of thermal energy utilization apparatus which will effectively reduce the temperature and/or pressure of the working medium as a consequence of the effective extraction of substantial quantities of energy from the working medium by such utilization apparatus, and normally provided with a return-flow line (usually ducting or the like) adapted to be connected from an output side of such utilization apparatus back to a low-thermal-energy input end of the flow-path-defining apparatus of the power conversion system. An important feature is the provision of, and the effective coupling with the solar energy conversion apparatus of, an automatic cut-in, auxiliary, heat-supplying standby apparatus coupled thereto in a manner such as to provide either a substantially constant desired level of thermal energy input into the working medium of the closed-cycle power conversion system despite input solar radiation thermal energy variations, or to provide for the maintainence of the total transferred thermal energy input within certain predetermined upper and lower limits.

Plant comprising an absorption heat pump

Abstract: In a system with at least one absorption heat pump (210) and a method for operating such a system, in which a working medium in an expeller (214) is expelled from an absorbent by supplying thermal energy of relatively high temperature, the expelled working medium in a condenser ( 218) is condensed, the condensed working medium is expanded in a expansion device (224), the relaxed condensed working medium is evaporated in an evaporator (228) with the supply of heat energy at a relatively low temperature and the evaporated working medium is absorbed again in the absorber in an absorber (234) the thermal energy for expelling the working medium from the absorbent is stored for the heat pump (210) in such a way that the thermal energy which can be removed from the memory is available at a temperature which is sufficient for expelling the working medium from the absorbent. A sorption store (246) is preferably used as the heat store, which contains a zeolite as sorbent and which can work part of a batch-wise additional absorption heat pump (212). Such a heat pump working with zeolite and preferably H2O as the working material system can also be used on its own with advantage for the production of useful heat of a relatively high temperature, e.g. Use 80 to 100 ° C and above and if necessary also for cooling.

Ion energetics in the Venus nightside ionosphere

Abstract: Consideration is given to the energetics of the ion gas flowing across the terminator into the Venus nightside ionosphere. Expressions are derived for the transport time of the ion gas (through 1 radian in solar zenith angle), the heat transfer time from the hot electron gas to the ions of an amount equal to the ion thermal energy), and the time required for vertical heat conduction to remove the internal energy of the ion column above a reference altitude, and it is shown that the time constant for transport is an order of magnitude smaller than the electron heat transfer time and comparable to the conduction time, and thus the ion gas is not a vertical conductive steady state. The conversion of bulk flow ion kinetic energy into heat is suggested as the mechanism responsible for the maintenance of the nightside ion temperatures at their observed values. It is thus concluded that the flow of the ion gas is quasi-adiabatic, and that steady-state, vertical, one dimensional energy balance models must be used with caution in the Venus ionosphere.