SEARCH · Engineering Papers

Results for “furnaces”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,225 records · Page 68

All sources NASA NTRS DOE OSTI

NASA NTRS1978

The suppression of low-temperature intergranular brittleness in ferritic Fe-Mn alloys

A method for obtaining cryogenic toughness in an Fe-12Mn-0.2Ti alloy by a controlled cooling technique is presented. The intergranular fracture surface of the quenched alloy, using an AES, revealed no significant difference from that obtained by the bulk transgranular fracture surface, indicating the absence of large-scale grain boundary segregation during the austenitizing treatment. Attention is given to the step cooling method, using a furnace at temperatures of 100 to 120 C, followed by fast cooling to ambient temperature, which in turn produces a high-impact toughness without intergranular brittleness. It is concluded that the sources of brittle intergranular fracture in the alloy are both chemical, operating in martensitic structure, and nonchemical, active during quenching from the austenitizing treatment.

Hwang, S. K.↗

NASA NTRS1980

Progress in MOSFET double-layer metalization

Report describes one-year research effort in VLSL fabrication. Four activities are described: theoretical study of two-dimensional diffusion in SOS (silicon-on-sapphire); setup of sputtering system, furnaces, and photolithography equipment; experiments on double layer metal; and investigation of two-dimensional modeling of MOSFET's (metal-oxide-semiconductor field-effect transistors).

Gassaway, J. D.↗

NASA NTRS1980

An automated oxide and diffusion facility for IC's

Report discusses totally-automated oxidation and diffusion facility for fabricating IC's. Several innovations are demonstrated: process controller specifically designed for semiconductor processing; automatic loading system to accept wafers from air track, insert them in quartz carrier, and place carrier on paddle for insertion into furnace; automatic unloading of wafers back onto air track; and boron diffusion using diborane.

Kennedy, B. W.↗

NASA NTRS1981

Three story residence with solar heat--Manchester, New Hampshire

When heat lost through ducts is counted for accurate performance assessment, solar energy supplied 56 percent of building's space heating load. Average outdoor temperature was 53 degrees F; average indoor temperature was 69 degrees F. System operating modes included heating from solar collectors, storing heat, heating from storage, auxiliary heating with oil fired furnace, summer venting, and hot water preheating.

Source record↗

NASA NTRS1981

Solar heating for an observatory--Lincoln, Nebraska

Report describes solar-energy system for 50 seat observatory that provides 60 percent of space heating needs. System includes 9 flat-plate collectors, rock storage bin, blowers, controls, ducting, and auxiliary natural-gas furnace; it has five operation modes. Net energy savings were 11.31 million Btu for 12 months, or equivalent of 1.9 barrels of oil. Report appendixes list performance factor definitions, performance equations, and average area weather conditions.

Source record↗

NASA NTRS1981

Single-family-residence solar heating--Carlsbad, New Mexico

Solar-heating and hot-water system includes 408 square feet of flat-plate air collectors, rock storage bin, energy transport system, air-to-water heat exchanger, controls, and hot-water preheat tank. Hot-air oil furnace supplies auxiliary space heating, and electricity powers air-handler blower and hot water preheat pump. For 12 month period, system provided 43 percent of space-heating and 53 percent of hot-water energy; net energy savings were 23.072 million Btu.

Source record↗

NASA NTRS1981

Mobile glazing unit

Unit programs thermal cycle from 100 to 2,300 F for firing ceramic gglaze coatings on refractory surfaces in any attitude and position. Device includes control console, heater assembly, protective cover, and manipulator boom; boom places heater next to surface to be fired. Unit is industrially useful for in situ repair of ceramics and curing individual refractory blocks during furnace maintenance.

Holt, J. W.↗

NASA NTRS1979

Engineering evaluation of existing space hardware for utilization in small self-contained payloads

The NASA small self-contained payload program allows research and development experiments of less than 5 cu ft to be flown in the Orbiter payload bay on a space available basis. Materials processing equipment available from Apollo, Skylab, SPAR, and MEA that include such items as furnaces for metallurgical processing and crystal growth, apparatus for measuring crystallization processes, and electrophoretic separators for cell separation are being offered by NASA through this program. Eighteen items for the self-contained payload program were evaluated and many were found to be suitable.

Lovoi, P. A.↗

NASA NTRS1977

Combustion noise

A review of the subject of combustion generated noise is presented. Combustion noise is an important noise source in industrial furnaces and process heaters, turbopropulsion and gas turbine systems, flaring operations, Diesel engines, and rocket engines. The state-of-the-art in combustion noise importance, understanding, prediction and scaling is presented for these systems. The fundamentals and available theories of combustion noise are given. Controversies in the field are discussed and recommendations for future research are made.

Strahle, W. C.↗

NASA NTRS1980

Directional solidification at ultra-high thermal gradient

A high gradient controlled solidification (HGC) furnace was designed and operated at gradients up to 1800 C/cm to continuously produce aluminum alloys. Rubber '0' rings for the water cooling chamber were eliminated, while still maintaining water cooling directly onto the solidified metal. An HGC unit for high temperature ferrous alloys was also designed. Successful runs were made with cast iron, at thermal gradients up to 500 C/cm.

Flemings, M. C.↗

NASA NTRS1980

Thin film temperature sensor

Thin film surface temperature sensors were developed. The sensors were made of platinum-platinum/10 percent rhodium thermocouples with associated thin film-to-lead wire connections and sputtered on aluminum oxide coated simulated turbine blades for testing. Tests included exposure to vibration, low velocity hydrocarbon hot gas flow to 1250 K, and furnace calibrations. Thermal electromotive force was typically two percent below standard type S thermocouples. Mean time to failure was 42 hours at a hot gas flow temperature of 1250 K and an average of 15 cycles to room temperature. Failures were mainly due to separation of the platinum thin film from the aluminum oxide surface. Several techniques to improve the adhesion of the platinum are discussed.

Grant, H. P.↗

NASA NTRS1980

Potentialities of TEC topping: A simplified view of parametric effects

An examination of the benefits of thermionic-energy-conversion (TEC)-topped power plants and methods of increasing conversion efficiency are discussed. Reductions in the cost of TEC modules yield direct decreases in the cost of electricity (COE) from TEC-topped central station power plants. Simplified COE, overall-efficiency charts presented illustrate this trend. Additional capital-cost diminution results from designing more compact furnaces with considerably increased heat transfer rates allowable and desirable for high temperature TEC and heat pipes. Such improvements can evolve of the protection from hot corrosion and slag as well as the thermal expansion compatibilities offered by silicon-carbide clads on TEC-heating surfaces. Greater efficiencies and far fewer modules are possible with high-temperature, high-power-density TEC: This decreases capital and fuel costs much more and substantially increases electric power outputs for fixed fuel inputs. In addition to more electricity, less pollution, and lower costs, TEC topping used directly in coal-combustion products contributes balance-of-payment gains.

Morris, J. F.↗

NASA NTRS1980

Effects of yttrium, aluminum and chromium concentrations in bond coatings on the performance of zirconia-yttria thermal barriers

A cyclic furnace study was conducted on thermal barrier systems to evaluate the effects of yttrium, chromium, and aluminum in nickel-base alloy bond coatings and the effect of bond coating thickness on yttria-stabilized zirconia thermal barrier coating life. Without yttrium in the bond coatings, the zirconia coatings failed very rapidly. Increasing chromium and aluminum in the Ni-Cr-Al-Y bond coatings increased total coating life. This effect was not as great as that due to yttrium. Increased bond coat thickness was also found to increase life.

Stecura, S.↗

NASA NTRS1980

Thermal energy storage systems using fluidized bed heat exchangers

The viability of using fluidized bed heat exchangers (FBHX) for thermal energy storage (TES) in applications with potential for waste heat recovery was investigated. Of the candidate applications screened, cement plant rotary kilns and steel plant electric arc furnaces were identified, via the chosen selection criteria, as having the best potential for successful use of FBHX/TES system. A computer model of the FBHX/TES systems was developed and the technical feasibility of the two selected applications was verified. Economic and tradeoff evaluations in progress for final optimization of the systems and selection of the most promising system for further concept validation are described.

Ramanathan, V.↗

NASA NTRS1980

Heat storage in alloy transformations

Heats of transformation of eutectic alloys were measured for many binary and ternary systems by differential scanning calorimetry and thermal analysis. Only the relatively cheap and plentiful elements Mg, Al, Si, P, Ca, Cu, Zn were considered. A method for measuring volume change during transformation was developed using x-ray absorption in a confined sample. Thermal expansion coefficients of both solid and liquid states of aluminum and of its eutectics with copper and with silicon also were determined. Preliminary evaluation of containment materials lead to the selection of silicon carbide as the initial material for study. Possible applications of alloy PCMs for heat storage in conventional and solar central power stations, small solar receivers and industrial furnace operations are under consideration.

Birchenall, C. E.↗

NASA NTRS1980

Heat storage in alloy transformations

The feasibility of using metal alloys as thermal energy storage media was investigated. The elements selected as candidate media were limited to aluminum, copper, magnesium, silicon, zinc, calcium, and phosphorus on the basis of low cost and latent heat of transformation. Several new eutectic alloys and ternary intermetallic phases were determined. A new method employing X-ray absorption techniques was developed to determine the coefficients of thermal expansion of both the solid and liquid phases and the volume change during phase transformation. The method and apparatus are discussed and the experimental results are presented for aluminum and two aluminum-eutectic alloys. Candidate materials were evaluated to determine suitable materials for containment of the metal alloys. Graphite was used to contain the alloys during the volume change measurements. Silicon carbide was identified as a promising containment material and surface-coated iron alloys were also evaluated. System considerations that are pertinent if alloy eutectics are used as thermal energy storage media are discussed. Potential applications to solar receivers and industrial furnaces are illustrated schematically.

Birchenall, C. E.↗

NASA NTRS1980

Cogeneration technology alternatives study. Volume 1: Summary report

Data and information in the area of advanced energy conversion systems for industrial congeneration applications in the 1985-2000 time period was studied. Six current and thirty-one advanced energy conversion systems were defined and combined with appropriate balance-of-plant equipment. Twenty-six industrial processes were selected from among the high energy consuming industries to serve as a framework for the study. Each conversion system was analyzed as a cogenerator with each industrial plant. Fuel consumption, costs, and environmental intrusion were evaluated and compared to corresponding traditional values. Various cogeneration strategies were analyzed and both topping and bottoming (using industrial by-product heat) applications were included. The advanced energy conversion technologies indicated reduced fuel consumption, costs, and emissions. Typically fuel energy savings of 10 to 25 percent were predicted compared to traditional on-site furnaces and utility electricity. With the variety of industrial requirements, each advanced technology had attractive applications. Overall, fuel cells indicated the greatest fuel energy savings and emission reductions. Gas turbines and combined cycles indicated high overall annual cost savings. Steam turbines and gas turbines produced high estimated returns. In some applications, diesels were most efficient. The advanced technologies used coal-derived fuels, or coal with advanced fluid bed combustion or on-site gasification systems.

Source record↗

NASA NTRS1980

Thermal energy storage systems using fluidized bed heat exchangers

A rotary cement kiln and an electric arc furnace were chosen for evaluation to determine the applicability of a fluid bed heat exchanger (FBHX) for thermal energy storage (TES). Multistage shallow bed FBHX's operating with high temperature differences were identified as the most suitable for TES applications. Analysis of the two selected conceptual systems included establishing a plant process flow configuration, an operational scenario, a preliminary FBHX/TES design, and parametric analysis. A computer model was developed to determine the effects of the number of stages, gas temperatures, gas flows, bed materials, charge and discharge time, and parasitic power required for operation. The maximum national energy conservation potential of the cement plant application with TES is 15.4 million barrels of oil or 3.9 million tons of coal per year. For the electric arc furnance application the maximum national conservation potential with TES is 4.5 million barrels of oil or 1.1 million tons of coal per year. Present time of day utility rates are near the breakeven point required for the TES system. Escalation of on-peak energy due to critical fuel shortages could make the FBHX/TES applications economically attractive in the future.

Weast, T.↗