Journal of Energy Engineering

The environmental and security advantages of underground storage of oil and gas are well documented. In many cases, underground storage methods such as storage in salt domes, abandoned mines, and mined rock caverns have proven to be cost effective when compared to storage in steel tanks constructed for that purpose on the surface. In good rock conditions, underground storage of large quantities of hydrocarbon products is normally less costly—up to 50–70% of the surface alternative. Under fair or weak rock conditions, economic comparisons between surface tanks and underground caverns must be evaluated on a case to case basis. The key to successful underground storage is enactment of a realistic geotechnical approach. In addition to construction cost, storage of petroleum products underground has operational advantages over similar storage above ground. These advantages include lower maintenance costs, less fire hazards, less land requirements, and a more even storage temperature.

The cyclone as a unit operation for processing airborne material in a waste‐to‐energy production facility is studied. The theories of cyclone design and operation are reviewed. Applications and modifications of the theories as appropriate to municipal solid waste processing are developed. The design of a cyclone for specific use in waste‐to‐energy production facilities is suggested.

Guidelines for quick and simple hydropower project cost estimates are developed for preliminary site assessments. The guidelines are based upon a concept which incorporates a single equation utilizing design power and head for total equipment cost and a “site factor” to determine total project cost. Total project cost is estimated by multiplying the equipment cost, obtained from the equation, and the site factor. Total project cost data from a number of hydropower projects are compiled to provide guidelines for choosing the site factor, which is shown to vary greatly, especially for micro $(⩽100\mathrm{kW})$ and mini $(⩽1\text{,}000\mathrm{kW})$ hydropower projects. Envelope curves for site factors are given, and a “weighting factor,” which is the fraction distance between upper and lower envelope curves, is chosen for each site. The choice of weighting factor for a given site is based upon comparison with recently completed projects, a knowledge of the components which can greatly increase civil works costs, and engineering judgement. The weighting factor is then used in calculations to determine optimum plant capacity. The methodology was used in a survey of the hydropower potential at existing Minnesota Dams, which is presented as a case study.

The existence of a density extremum in water at 4 °C, and the resulting nonlinear relation between density and temperature gives rise to densimetric flows, which are markedly different from those in the linear range. Experiments are described that give some insight into the phenomenon of the thermal bar and the manner in which it may influence nearshore transport processes in the vicinity of a thermal outfall in a cold climate. The results are significant for the design of power station circulating water systems that must operate in severe winter conditions.

Power losses at the Moses-Saunders Power Dam due to the existence of an ice cover in the St. Lawrence River between the Iroquois Dam and the Power Dam are analyzed for the twenty-five winters between 1958 and 1983. The analysis shows that the average power loss per winter was 49,180 MW-hrs, which is equivalent to 82,131 barrels of oil or 2.46 million dollars. Major factors which affectt the magnitude of the power loss are the initial roughness of the river ice cover and the size of the remaining open water area.