Journal of Energy Engineering

Stability‐dependent and Dalton‐type mass transfer formulas are determined from experimental evaporation data in ambient and heated channels and are shown to have similar performance in prediction of evaporation. The formulas developed are compared with those proposed by other investigators for lakes and flowing channels. The evaporation data were obtained from a heat‐budget analysis of two large outdoor channels, one of which received ambient‐temperature water from an adjacent reservoir while the other received an artificially‐heated discharge. Daily evaporation was calculated from bihourly values of water temperature and hourly values of meteorological variables for a 63‐day study period in the summer. The evaporation data were then used to derive mass transfer evaporation formulas for heated and ambient flowing channels.

An existing desert site for hazardous chemical and low‐level radioactive waste disposal is evaluated for suitability. This site is characterized using geologic, geohydrologic, geochemical, and other considerations. Design and operation of the disposal facility is considered. Site characteristics are also evaluated with respect to new and proposed regulatory requirements under the Resource Conservation and Recovery Act (1976) regulations, 40 CFR Part 264, and the “Licensing Requirements for Landfill Disposal of Radioactive Waste,” 10 CFR Part 61. The advantages and disadvantages of siting new disposal facilities in similar desert areas are reviewed and contrasted to siting in humid locations.

Mechanisms that contribute to glass contamination of waste‐to‐energy products from air classifiers are studied, and modifications to unit processes are suggested. Vertical air classifiers are used to extract the combustible organic fraction from municipal solid waste (MSW); however, unit operations preceding these classifiers tend to produce glass particles which, despite a relatively high density, tend to move with the organics once they reach the classifier. Experience in burning waste‐to‐energy fuel indicates critical problems are associated with the presence of these inorganic fines in the fuel, including excessive slagging on incinerator walls and abrasion of mechanical parts. This research investigates the relationships between glass particle size and air velocity within the classifier, and details the effects paper particles and moisture have on glass particle transport. Laboratory results lead to conclusions which suggest changes in the operation of air classifiers, and imply designs for selected unit operations which precede the classifiers.

The fundamental aspects of zigzag air classifier configurations are studied in terms of the design and operation of a waste‐to‐energy production facility. The development of a method of performance evaluation defined by operating range is examined. Historically, air classification has been used in industry and agriculture in mineral extraction, limestone sizing, and seed and grain cleaning. However, the adaption of air classifiers to resource recovery and waste‐to‐energy production facilities presents new problems due to the complex and variable nature of the wastes. A series of configurations providing a continuous range of zigzag classifier shape components are tested. Each configuration is evaluated to determine its efficiency of separation, and sensitivity to operating air speeds. Results indicate that the configuration of a zigzag classifier does not influence its peak efficiency of separation. However, findings point to distinct limits on operating parameters which lead to peak efficiencies for the different configurations. These operating range values represent the sensitivity of the air classifier to changes in the air flow. A major finding concerns the effect of configuration on the particle size distribution observed in the material exiting the classifier: smaller particles appear to be influenced by configuration changes and larger particles do not. A new method for classifier performance evaluation is developed and applied.

The damage to power station equipment due to earthquakes has necessitated a study of the dynamic behavior of electrical systems. A 220kv voltage transformer is theoretically analyzed and experimentally tested under steady‐state sinusoidal vibrations. A new test criterion is suggested based on dynamic response of the system during a postulated design earthquake to assess the earthquake withstand capability of the system. Making use of free vibration results of natural frequency and damping of the transformer, the maximum response, which is likely to occur at various locations of the equipment, is evaluated analytically. Shaking table tests are done to achieve the aforementioned design response. A new scheme is suggested to simulate the dynamic loading by equivalent static loading in a rational manner.

A combination of technologies that could help solve energy supply problems currently facing urban utilities is discussed in this paper. The concept employs a large coal‐gasification and gas clean‐up plant located outside the city, feeding a dedicated pipeline. Several cogenerating fuel cell power plants dispersed throughout the city and fueled through the pipeline produce electricity and cogenerate steam for local distribution. There are both economic and environmental benefits in this concept. Shifting from oil to coal while using more efficient conversion technologies reduces fuel expenditures. Placing generating capacity close to the load center offers an opportunity to utilize thermal energy that would otherwise be rejected as waste heat. Since this energy can be recovered at low cost, it may be possible for the utilities to operate a competitive district heating system. Unique environmental advantages result from splitting the power plant into two components, making it possible to place the gasifier, which must handle and process coal, outside the urban area. The fuel cel plants located in the city itself burn only clean fuel and produce little pollution.

Hawaii is the state most vulnerable to dislocation in the global energy market, with more than 91% of its total energy coming into the state as imported oil—two thirds of which is foreign crude. This near‐total dependence on seaborne petroleum is a paradox, since Hawaii has a wide variety of renewable energy resources which can serve as alternatives to oil. These renewable resources have the potential of being less polluting than conventional energy supplies and so are consistent with Hawaii's concern for the quality of life. For the past decade Hawaii has been engaged in a comprehensive program of resource assessment, research, development, demonstration, and commercialization of its indigenous energy resources: direct solar, wind, biomass, ocean thermal, geothermal. Sufficient progress has been made to date with a number of these energy alternatives, so that Hawaii should be able to maintain its momentum toward achieving energy self‐sufficiency—even in the face of drastic reductions in federal support for renewable energy RD&D and the present declining cost of oil.