Continuous Electric Power Research Articles

Thermal Power Regulation System for Pulsed Fusion Reactor.

A new method of generating continuous electrical power using a pulsed DT tokamak fusion reactor is described.The system consists of an electrolysis-cell hydrogen producer and pulsed fusion reactors so as to keep continuous electric power output level by regulating thermal power flow in the reactor coolant circuit.It also protects reactor structures and turbine blades from repeated thermal stresses caused by pulsed operations or by disruptive instabilities.In case of the reactor with a thermal output power of 3 GW and with an operation as long as 20h with a dwell time of 5 min, the circulation power necessary for generating hydrogen fuels used for regulating thermal power level is only 15.3 MW.A sufficient amount of deuterium fuels is produced as by-products.

Automated bus transfer control for critical industrial processes

The techniques and methods for maintaining continuous electrical power to petroleum and chemical facilities from two or more utility feeders by an automated bus transfer logic controller (ABTLC) system are discussed. The purpose of this system is to reduce transients, torsional forces, inrush currents, and motor stress while maintaining continuous motor operation when the primary utility source experiences an interruption, and the operating facility transfers the motor load to an alternative source of electrical supply. The engineering studies, application considerations, motor control design requirements, installation, and operation of the automated bus transfer controller for a chemical facility are presented and discussed. The present bus transfer methods are reviewed. The effectiveness of these methods using typical buses is discussed. The influence of bus voltage and phase angle characteristics during bus transfer for determining the heat transfer technique is also analyzed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

On-orbit experiment plan on solar thermodynamic power system

This paper presents the on-orbit experiment plan of the solar thermodynamic power system operating the space flyer unit (SFU) presently being developed in Japan. The on-orbit experiments will be conducted with four primary objectives. First, to demonstrate the operation of the solar thermodynamic system in space environment. Second, to assess the performance capability of the solar thermodynamic system in space. Third, to verify functions of thermodynamic engine, solar ray collector, thermal storage system and space radiator especially from view point of durability and reliability. Fourth, to examine how vibration and inertia caused by moving parts of thermodynamic engine affect the primary functions of SFU and other mission payloads. The solar thermodynamic power system consists of a free piston-type Stirling engine, a linear synchronous generator, a Cassegrain-type solar ray collector, a thermal storage system and a space radiator. This system produces the continuous electric power of 2.5 kW, 330 V a.c. using 4.3 m dia solar collector. The output power is fed to the MPD thruster experiment. This experiment is proposed for the second SFU mission called “Energy Mission” in the mid 1990s. As a preliminary experiment, the ballistic flight experiment using sounding rocket is also planned.

Twenty-Five Years of Operating Experience With the Coal-Fired, Closed-Cycle Gas Turbine Cogeneration Plant at Coburg

The only commercially running closed-cycle gas turbine in the world delivering electricity as well as heat to a public utility and a heating network, is the heat and power station in Coburg, West Germany. The plant is fired exclusively with pulverized coal and uses air as the working medium. It has a maximum continuous electric power output of 6.6 MW into the grid and up to 16 MW of direct heating capacity into the town’s heating network. The plant has accumulated 150,000 operating hours to date (approximately 7000 hrs per year); it is scheduled to remain in service during the following years due to its excellent performance. Since relatively little has been published about the plant in the technical literature, a report about its design and operating experience is presented here.

Thermal Preconditioning Utilizing a Radioisotope Heat Source

Gyroscopes and accelerometers used as sensors in inertial navigation systems have errors which change with temperature. In order to obtain adequate performance from these devices; precise, elevated (above ambient) temperatures are usually required to aid in maintaining close tolerances of temperature control. Most systems include electrical heaters on these sensors for this purpose. The time required for the sensors to reach operating temperature has been excessive, especially if the ambient temperature is low. Thermal preconditioning eliminates the warmup time by maintaining the entire inertial measurement unit (IMU) near the operating temperature of the sensors. This technique has not been practical in the past because continuous electrical power could not be provided and sources of portable power were not adequate to supply the heating requirements of large inertial systems. The size of inertial systems has been decreasing and the small systems can be kept near operating temperatures with less than 65 watts of thermal power even at low temperatures. A joint AEC/Air Force program to test the feasibility of using radioisotopes as heat sources to keep the inertial measurement unit at or near operating temperature was conducted. This paper discusses the design, operation and test of the thermal preconditioning unit utilizing a radioisotope heat source. Thermal and radiological safety aspects are also included in the discussion.

Uninterruptable Power for Critical Loads

A description of the design and performance of high-power thyristor inverters for uninterruptable power systems is presented. These inverters have been designed to provide precisely regulated and continuous ac electrical power for critical loads, such as real-time data processing computers, air route traffic control centers, and industrial process control equipment. High reliability, over 80 000 hours MTBF, is achieved by utilizing a parallel redundant system configuration. Systems have been designed with ratings of up to 2000 kVA. Typical instantaneous voltage transient limits are plus 10 and minus 10 percent. Frequency tolerance is plus or minus one-half percent. Total harmonic distortion is less than 5-percent rms.

Treatment for High Iron Content in Remote Alaskan Water Supplies

This article discusses a problem with high iron content in the well water supply of three Alaskan towns. Such water supply situations are widespread in remote Alaskan communities. High hardness in all three supplies presented a treatment challenge that was magnified by lack of continuous electric power and very low winter temperatures. Batch lime treatment, settling, and decantation reduced the iron content and the hardness at two of the three towns. Aeration, batch lime treatment, settling, and decantation reduced the iron content and the hardness at the third. The resulting waters were free of chlorine demand and tastes and odors. Jar tests were used to determine the optimum lime doses.

An Underwater Thermoelectric Reactor Plant

A conceptual design is presented for an underwater thermoelectric nuclear power plant capable of producing continuous electric power at a 100-kwe level. The inherent advantage of a self-pressurized, natural circulation, pressurized water reactor (PWR) system is combined with a direct-conversion thermoelectric generator to provide a completely static system. The plant is designed for remote startup and completely unattended operation for over five years. Power is produced directly at 40 v; however, utilization of a solid-state inverter and storage batteries provides a peaking capability of several megawatts(e) at higher voltages. A low enriched core, with an inherently high negative temperature coefficient, is used which allows the control rods to be withdrawn completely at plant startup and to remain static throughout design life. No electronic controls, power monitoring, or feedback systems are required for operation or safety. Segmented thermoelectric elements (PbTe and BiTe) are used to obtain optimized performance over the rather small temperature drop available at the couple junctions. Although system weight is strongly dependent on design depth—-80,000 Ib for 18,000 ft'—-advanced pressure balancing concepts would allow weight reductions of 50 to 70% plus higher temperatures for improved thermoelectric conversion efficiencies.

Preliminary design of a solar-electric test satellite

This paper describes a noil-nuclear orbital test system capable of providing the long-duration space environment and power level required to qualify for space the electric propulsion engines now under NASA development. The vehicle makes use of a deployable flat-panel, solar-cell array operating in a near-polar orbit to provide reliable continuous electrical power for periods in excess of 150 days. The operation of electric thrusters will cause the test vehicle to spiral slowly upward, thus presenting an excellent platform from which to conduct such scientific experiments as a spatial survey of the intensities of the energetic particles trapped in the earth's magnetic field and a World Magnetic Survey.