Showing papers on "Thermal energy published in 1988"

Cogeneration system and method

Abstract: A cogeneration system including a heat engine driving an electrical generator coupled to electrical lines at a site serviced by a utility. The system includes supervisory means for monitoring the electrical energy and power supplied by the generator, supplied to the site by the utility, and consumed by site electrical loads, for storing monitored electrical data, and for controlling operation of the engine and generator in response to the data. The system is further provided with data representative of the utility rate structure, a real-time clock, and controls operation of the system in accordance with time which corresponds to a utility peak, intermediate, or off-peak energy rate period. The system further comprises means for monitoring the thermal energy transferred from the engine to a site thermal load by heat exchange means. Further disclosed is circuitry for monitoring energy and power in electrical distribution lines and providing interlocking functions to multiply voltage and current representative signals, a voltage to frequency converter, and a gated counter for integrating by counting the converted frequency signal over time. Finally, a multiple-unit cogeneration system of the disclosed systems communicating over a local area network, with one unit designated as a "lead" unit at a given time is disclosed. A method is also disclosed for performing the various functions of the system.

Thermal energy from environmental fluids

Abstract: A method of utilizing the thermal energy of environmental fluids to produce mechanical work or electricity by an energy conversion system wherein: the source fluid gives heat to the working fluid of a prime mover through a first heat exchange means and is cooled thereby; the cooled source fluid effluent from the said first heat exchange means is further cooled by passing it through a further cooling system which includes either a turbine or an expansion device or both; the further cooled source fluid is employed to cool the expanded working fluid of the prime mover, and the source fluid effluent from the energy conversion system may be used for other cooling and refrigeration processes, such as desalination of seawater, cooling of superconductors, etc

Method of converting thermal energy to work

Abstract: A method is provided for converting sensible heat energy of a heating fluid supplied by a high-temperature heat source to work, by means of a thermodynamic cycle employing a multi-component working fluid, wherein a "rich solution" having a higher concentration of lower boiling component, or components, is heated in a vapor generator in counter-current heat exchange with the heating fluid to produce a vapor-liquid mixture which is introduced into a lower zone of a rectifier and separated therein into a "lean solution" having a higher concentration of said lower boiling component, or components, and a vapor mixture; the enthalpy of the vapor mixture is increased by passing it through a superheater in counter-current heat exchange with said heating fluid at its highest temperature; the vapor mixture is then expanded in a first turbine to an intermediate pressure level thereby to generate work and subsequently in a second turbine to a low pressure level to generate additional work; the spent vapor mixture is then recycled to an absorber wherein it is dissolved in said lean solution so as to regenerate said rich solution. The cycle is characterized mainly in that a portion of said lean solution emerging from the rectifier, is decompressed, by means of an expansion device, into a so-called flash drum wherein the lean solution separates into a yet leaner solution and a vapor mixture which is expanded in a turbine to produce additional work.

Potential energy surface morphology and the variation of dissociative chemisorption probabilities with kinetic energy and angle: N2/W(110)

Abstract: Stochastic molecular dynamics simulations are used to calculate the dissociation probability S0 of N2 on W(110). The results obtained are in good agreement with the experimental data both in magnitude and dependence on incident kinetic energy and angle. The dependence of S0 on the total kinetic energy, in distinction to the normal kinetic energy, is interpreted in terms of the narrow and steep transition state region and the attractive well of the potential energy surface.

Building block composite design and method of making for RF line replaceable modules

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.

Heat dissipation in microelectronic systems using phase change materials with natural convection

Abstract: The present study is an initial investigation of the use of phase change materials with natural convection for the dissipation of thermal energy in a model of an integrated circuit (IC) acting as a heat source. A 1.91cm diameter long copper cylinder filled with a phase change material (PCM), P-116 Sunoco wax, was used as the heat exchange structure. The effectiveness of the PCM cylinder was found to be a strong function of the geometrical arrangement. With the cylinder of PCM positioned on top of the heating cartridge (which simulated the IC heat source), the gravitationally induced natural convection currents are shown to play a significant role in dissipating the heat generated by the cartridge. In an inverted position the effects of natural convection currents were not apparent. The effective thermal conductivity of the cylinder containing the melted wax was at least an order of magnitude higher when positioned above the heating cartridge than when positioned below. Pictures of the melting process were...

Solar energy thermally powered electrical generating system

Abstract: A thermally powered electrical generating system for use in a space vehicle is disclosed The rate of storage in a thermal energy storage medium is controlled by varying the rate of generation and dissipation of electrical energy in a thermally powered electrical generating system which is powered from heat stored in the thermal energy storage medium without exceeding a maximum quantity of heat A control system (10) varies the rate at which electrical energy is generated by the electrical generating system and the rate at which electrical energy is consumed by a variable parasitic electrical load to cause storage of an amount of thermal energy in the thermal energy storage system at the end of a period of insolation which is sufficient to satisfy the scheduled demand for electrical power to be generated during the next period of eclipse The control system is based upon Kalman filter theory

Means and method for preventing unwanted accumulation in heat exchangers

Abstract: A heat exchange element in the form of a tube, lies in a particulate laden gas flow and is charged with an electrostatic charge of the same polarity as an electrostatic charge on particles suspended in the gas flow, in order to prevent accumulation on any part of the heat exchange element which would interfere with the rate at which thermal energy can be transferred through the heat exchange element or restrict flow of gas through the heat exchanger.

Thermal energy storing material composition

Abstract: PURPOSE: To obtain a thermal energy storing material composition, capable of reducing supercooling degree and sustaining effects of a nucleating agent even after thermal melting and withstanding repeated use, by adding a specific nucleating agent to a mixture of sodium carbonate.decahydrate with disodium hydrogenphosphate.dodecahydrate. CONSTITUTION: The objective composition obtained by adding (C) about 0.1-20wt.% (preferably about 0.5-10wt.%) aluminum phosphate, lead phosphate or calcium carbonate as a nucleating agent to a mixture of (A) about 80-30mol% sodium carbonate.decahydrate with (B) 20-70mol% disodium hydrogenphosphate.dodecahydrate. COPYRIGHT: (C)1989,JPO&Japio

Fusion Applications and Market Evaluation (FAME) Study

Abstract: : This report discusses the known applications of fusion energy and estimates possible market. Because fusion reactors can generate surplus neutrons (10 times greater than fusion), other valuable products can be made besides thermal energy for electrical power. The purpose of this study was to explore the many other products that could result from neutronic interactions, from the volumetric nature of nuclear heating, and from use of electromagnetic and charged particle energy. Even with other products being sold, electricity is the major product of the neutron thermal energy and sale of it is generally required for acceptable economics. Other products that are either unique to fusion or can be generated in great quantities that are otherwise unattainable are: (1) fissile fuels; (2) tritium; (3) radioisotopes; especially cobalt 60; and (4) some rare metals. In particular, the market for cobalt 60 is expected to grow substantially as the food irradiation industry matures. To a limited extent, the fusion neutrons might also be used to transmute fission waste and for radiation testing sources. Thermal energy from fusion reactors can be used fro nonelectrical applications such as synthetic fuel production, industrial process heat, and district heating. Inherently safe reactor designs with low activity materials could be sited near the thermal energy user. Finally, in the long term, the high energy content of fusion fuel makes it an interesting possibility as a power source for deep space missions.

Transport of thermal energy by a simple two‐phase loop

Abstract: A loop filled with a phase changing fluid is proposed as a device capable of transferring heat power from a generation place to a user Through the solution of a set of non-linear equations, operating conditions of the system are determined It is seen that even large amounts of energy can be transported under relatively small mass flow rates and differences of pressure and temperature Then only a small degradation of the energy conveyed takes place The operating conditions of the system are sensitive to the filling degree and the inner diameter of the loop pipe

Thermal remote anemometer system

Abstract: A sample in a wind tunnel is radiated from a thermal energy source exteriorly of the wind tunnel. A thermal imager system, also located exteriorly of the wind tunnel, reads surface radiations from the sample as a function of time. The produced thermal images are characteristic of the heat transferred from the sample to the flow across the sample. In turn, the measured rates of heat loss of the sample are characteristic of the flow and the sample.

Controlled process for the production of thermal energy from gases and apparatus useful therefor

Abstract: A method of and apparatus for obtaining the release of energy from a gas mixture including hydrogen and oxygen in which charged ions are stimulated to an activated state, and then passed through a resonant cavity, where successively increasing energy levels are achieved, and finally passed to an outlet orifice to produce thermal explosive energy.

Seasonal Storage of Thermal Energy—Swedish Experience

Abstract: Sweden reacted to the oil crises of the 1970s by initiating a comprehensive programme of research into, and development of, alternative energy sources. One of the problem areas in this connection is that of energy storage. This paper describes documented Swedish experience of seasonal thermal energy stores, concerned with such aspects as heat balances, heat losses, water sealing, stratification and temperature fields in heat stores and their surroundings. The paper concludes with mention of a number of design guidelines developed from Swedish R and D experience.

Global energetics of fast magnetic reconnection

Abstract: We examine the global energetics of a recent weakly nonlinear theory of fast steady-state reconnection in an incompressible plasma (Jardine & Priest 1988). This is itself an extension to second order of the Priest & Forbes (1986) family of models, of which Petschek-like and Sonnerup-like solutions are special cases. While to first order we find that the energy conversion is insensitive to the type of solution (such as slow compression or flux pile-up), to second order not only does the total energy converted vary but so also does the ratio of the thermal to kinetic energies produced. For a slow compression with a strongly converging flow, the amount of energy converted is greatest and is dominated by the thermal contribution, while for a flux pile-up with a strongly diverging flow, the amount of energy converted is smallest and is dominated by the kinetic contribution. We also find that the total energy flowing out of the downstream region can be increased either by increasing the external magnetic Mach number Me or the external plasma beta βe Increasing Me also enhances the variations between different types of solutions.

The role of the internal energy in the distribution function of a heat conducting gas

Abstract: Using a state-selective optical technique, we have measured directly the nonequilibrium distribution function f in heat conducting iodine gas as a function of the rotational and vibrational quantum numbers. The results show that, contrary to the case for translational energy, no rapid convergence exists for the expansion of f in polynomials (Wang-Chang-Uhlenbeck polynomials) containing the rotational or vibrational energy. The weight of the polynomials quadratic in the internal energy relative to polynomials of the first degree in the internal energy is found to be about 9% for the rotational energy and about 27% for the vibrational energy.

Thermally Regenerative Hydrogen/Oxygen Fuel Cell Power Cycles

Abstract: Two thermodynamic power cycles are analytically examined for future engineering feasibility. These power cycles use a hydrogen-oxygen fuel cell for electrical energy production and use the thermal dissociation of water for regeneration of the hydrogen and oxygen. The first cycle uses a thermal energy input at over 2000K to thermally dissociate the water. The second cycle dissociates the water using an electrolyzer operating at high temperature (1300K) which receives both thermal and electrical energy as inputs. The results show that while the processes and devices of the 2000K thermal system exceed current technology limits, the high temperature electrolyzer system appears to be a state-of-the-art technology development, with the requirements for very high electrolyzer and fuel cell efficiencies seen as determining the feasibility of this system.

Thermal power generating device

Abstract: PURPOSE:To extract thermal energy from a heat source to the utmost limits as electric energy by combining a semiconductor element having a relatively low thermal resistance with the semiconductor element having a relatively high thermal resistance in conformity with a cascade system. CONSTITUTION:The second P-type and N-type semiconductor elements 16 and 17 having thermal resistances that are superior to those of the P-type and N- type semiconductor elements 13 and 14 are alternately arranged on a ceramic substrate 11 and both elements 16 and 17 are electrically connected in series. Facing the ceramic substrate 11, the ceramic substrate 15 is attached as an endothermic plate. Once a heat source comes in contact on the ceramic substrate 15, the ceramic substrate 15 is maintainted at a high temperature and the ceramic substrate 12 is maintained at a low temperature and an electric potential difference develops between terminals 18 and 19 according to a temperature difference between ceramic substrates 15 and 12 in conformity with what is called the Seebeck effect and then, if the terminals 18 and 19 are connected to a load, electric energy can be extracted.

Development of an integrated heat pipe-thermal storage system for a solar receiver

Abstract: An integrated heat pipe-thermal storage system was developed as part of the Organic Rankine Cycle Solar Dynamic Power System solar receiver for space station application. The solar receiver incorporates potassium heat pipe elements to absorb and transfer the solar energy within the receiver cavity. The heat pipes contain thermal energy storage (TES) canisters within the vapor space with a toluene heater tube used as the condenser region of the heat pipe. During the insolation period of the earth orbit, solar energy is delivered to the heat pipe. Part of this thermal energy is delivered to the heater tube and the balance is stored in the TES units. During the eclipse period of earth orbit, the stored energy in the TES units is transferred by the potassium vapor to the toluene heater tube. A developmental heat pipe element was constructed that contains axial arteries and a distribution wick connecting the toluene heater and the TES units to the solar insolation surface of the heat pipe. Tests were conducted to demonstrate the heat pipe, TES units, and the heater tube operation. The heat pipe element was operated at design input power of 4.8 kW. Thermal cycle tests were conducted to demonstrate the successful charge and discharge of the TES units. Axial power flux levels up to 15 watts/sq cm were demonstrated and transient tests were conducted on the heat pipe element. Details of the heat pipe development and test procedures are presented.

Washer liquid atomizing device

Abstract: PURPOSE:To facilitate elimination of sticking ice by furnishing a heat accumulation type heat exchanger to accommodate heat accumulative substance which generates overcooled state at the time of radiation after heated melting, allowing the heat accumulative substance to emit heat through contacting of a crystal nucleus forming substance, and thereby heating the washer liquid. CONSTITUTION:When a car is running, a communication on/off means 5 is set to the break side (solenoid valve 50 closed), and a PTC heater 3 is heated, and the heat emitted is supplied to a heat accumulative substance 21 to cause fusion thereof. The molten heat accumulative substance 21 is cooled while overcooled condition is retained, and thereby the absorbed thermal energy can be accumulated lastingly in the form of latent heat at solidification. In case ice has stuck to the windshield glass during winter period, the above-mentioned communication on/off means 5 is set to the communication side (solenoid valve 50 open) to allow contact of the heat accumulative substance 21 with a crystal nucleus forming substance in a seed crystal vessel 4, and thereby overcooled state is collapsed to cause temp. rise of the heat accumulative substance 21. Washer liquid 60 is heated using this heat and atomized off from atomizing nozzles 64, 65 in the form of warm water.

Surface structure of heat accepting plate in flowing-down type heat collector

Abstract: PURPOSE:To provide a heat accepting plate which does not require any attention for its installing attitude and which is superior in its mass production as well as its installing work at site by a method wherein a flexible material is adhered to a surface of a raw material of the heat accepting plate so as to restrict the direction of flowing-down thermal accepting medium liquid. CONSTITUTION:A raw material 1 has a width of about 5mm, for example. Some raw materials are arranged in parallel with a similar spacing 2 being left therebetween. Raw materials 1 having a width of about 1mm or so, for example, may be repeatedly arranged in their rough and close relationship to each other. Several raw materials 1 having several millimeters are adhered in corrugated form with several centimeters spacing and a linear raw material 1a may be arranged between these corrugated raw materials 1. These materials are suitable for a flowing-down type heat collector having a relative high flow rate. In case a flow rate is relatively low, a patter of the raw material IC is provided with an inclined portion, a receiving portion IC' placed at upstream side of the inclined portion and a delivery portion IC'' placed at a downstream side opposite to the upstream side. These raw materials are arranged in staggered form, for example, and arranged in ether one row or a plurality of rows over the width of the heat accepting plate 3. Thermal heat accepting medium liquid supplied to the inclined portion or the accepting portion IC' is transmitted to the accepting portion IC'' and flowed down gradually to the accepting portion IC'' of the lower raw material and the accepting portion IC''.

Geothermal energy assessment

Abstract: This section considers the magnitude of the energy contained in the rocks and in the fluids within a geothermal reservoir. Unlike oil and gas reservoirs in which the energy resource is the fluid itself, geothermal fluid has little inherent value and is simply a carrier of the energy. The principal value of a geothermal reservoir to a developer lies in the thermal energy it contains — the fluid is useful only in bringing that energy to the surface.

Junction inspecting method of electronic part

Abstract: PURPOSE:To judge the quality of a junction, by projecting thermal energy on a part to be measured, receiving radiated infrared rays, forming the image of temperature distribution of the part to be measured, and comparing the image with a standard temperature distribution pattern. CONSTITUTION:A lead wire 4 of an electronic part 3 is bonded to a conductor pattern on a printed board 1 through a solder 5. An energy beam 6 such as a laser beam is projected on the lead wire 4 of the electronic part 3. Of the projected thermal energy, infrared rays 7, which are emitted from a material to be measured, i.e., the solder part 5, are received with an infrared-ray image sensor 8. A thermal image, which reflects the temperature distribution of the material to be measured, is formed. The thermal image is transduced into an electric signal. The signal undergoes image processing, and the result is displayed on a display device 25. In this procedure, the excellent or defective state of the soldering of the material to be inspected can be found.