Thermal Electric Power Plants Research Articles

Los Angeles County acts to control emissions of nitrogen oxides from power plants.

Downtrends have been established in emissions of all major air pollutants in Los Angeles County except nitrogen oxides. Thermal electric power plants constitute the County’s largest stationary source of nitrogen oxides and are clustered in discrete “source areas” where high ambient levels of NOx are recorded.

The multipurpose use of ash and clinker wastes of thermal electric power plants in hydrotechnical construction

1. The use of secondary resources will greatly increase the output of industrial, mainly building, products with smaller specific capital expenditures and operating expenses in comparison to such production using traditional raw materials. 2. The use of secondary resources usually eliminates additional labor and transportation expenses associated with the effect of seasonal extraction of the primary raw material, which also reduces expenditures for storing its necessary reserves. 3. In connection with the development of the practice of joint construction of a hydropower system and industrial power complex, almost all aspects of the possible use of ash and clinkers of thermal electric power plants are of unquestionable interest for hydrotechnical construction. 4. The successful implementation of the multipurpose utilization of ash-clinker wastes requires the development of a system for economic stimulation of workers involved in the timely delivery of ash having standard properties and of materials of ash-clinker dumps, their transport, and comprehensive use.

The Earth's Heat: A New Power Source

current short-term energy crisis (SN: 11/14, p. 379), the long-term finiteness of fuel resources and the increasing success of environmentalists in stalling the building of new generating plants are causing utility engineers to look more and more to geothermal reservoirs as a possible source of electrical energy. Tapping these naturally occurring pools of hot water beneath the earth's surface would cause few of the pollution problems created by conventional or nuclear generators and could supply huge quantities of energy. Most geothermal development to date has been in nations such as Japan and Italy where there is a shortage of fossil fuels. But the picture is changing rapidly. The United States has not been so hungry for sources of energy other than fossil fuels or the atom, says an Interior Department official. With the increasing emphasis on environmental pollution, however, a new attitude is developing toward geothermal power, he says. Engineers who once scoffed at it as a pipe dream are now taking a second look. And the increased interest is reflected in activity such as the formation of new companies devoted to geothermal prospecting, as well as in new interest by giant energy firms. United States Tax Court has declared geothermal resources eligible for a percentage depletion allowance of the kind that has made oil companies the envy of other energy producers. Another large stimulus has come from a report this year from the University of California at Riverside. report concerns itself with a single geothermal site, California's Imperial Valley (SN: 2/1/69, P. 113). It indicates that if the geothermal resources there were fully utilized, 20,000 to 30,000 megawatts of electric generating capacity could be installed. Other nations-both those traditionally interested in geothermal power and some newcomers to the fieldare also taking a new look at geothermal resources, and the Soviet Union is now carrying out wide-scale mapping of temperature gradients to discover the best areas for geothermal prospecting. source of geothermal energy is the molten rock, or magma, in the earth's interior. When underground water comes into contact with the magma, hot water and steam are produced. Among the conditions necessary for the existence of a tappable source of geothermal energy are a large chamber of magma relatively close to the surface and large and porous underground reservoirs with channels connected to the heat source. Where these conditions exist, as in Imperial Valley, wells of a depth within the means of current technology will produce geothermally heated water. There is also a possibility, not yet fully confirmed, that the geothermal energy might be a self-renewing resource. Dr. Robert W. Rex, director of the UC study, estimates the average cost of the thermal energy to be about two cents per million British thermal units, compared with the 20 to 30 cents and more that energy from fossil-fuel or nuclear sources costs. Capital costs involved in developing this energy for power would probably be comparable to those for ordinary fossil-fuel plants. same turbinegenerator arrangement would be used. Substituting for the boiler of fossil-fuel plants and the reactor and heat exchanger of nuclear plants would be wells and flashing units that would collect the hot water and steam from the geothermal reservoirs and convert it to the clean, dry steam-with no condensed water in it-necessary for electric generation. Imperial Valley geothermal resource became more attractive when the salinity of most of the geothermal reservoirs was shown to be lower than earlier thought. brine, largely sulfate free, of those portions of the Imperial Valley sources not near the Salton Sea has a relatively low salt content of 1.5 to 2.5 percent. In the ground, the brine has a temperature of 500 degrees F. and a pressure of about 2,000 pounds per square inch. About 20 percent of this brine can be converted in flashers to the hot, dry steam needed for power production. But there is enough heat in the remaining brine to distill about 90 percent of it into fresh water before the dissolved solids begin to precipitate in the residue. leftover, highly concentrated brine can be pumped into wells isolated from the useful geothermal reservoirs. With full use of the capacity of the Imperial Valley resource, it might be possible to produce 5 million to 7 million acre-feet of fresh water annually from the wells-a valuable by-product for irrigation and other uses in the water-short lower Colorado River Basin. Generally speaking, any thermal electric power plant is most useful for producing base-load power, or meeting constant demand. It takes a long time to heat up a boiler and turbine, and the PG & E

Horizontal Surface Discharge of Warm Water Jets

Large thermal-electric power plants use an average of 1.5 cfs per Mw cooling water, with a temperature rise of about 10 F to 20 F, and flow velocities with a mean of about 7 fps; the resulting densimetric Froude numbers range from 2.5 to 12.5. A review of laboratory studies and prototype measurements, together with additional laboratory studies reported herein, indicate that this is in the range of transition from jet mixing to surface spreading regimes, with the possibility of a third regime existing for the lowest densimetric Froude numbers. Turbulence level in the jet, described by a Reynolds number, is of considerable importance in the transition region. It appears that the mixing by turbulence in the receiving water of the prototype is of equal importance to the mixing by the turbulence within the prototype jet.

Atmospheric pollution considerations affecting the ultimate capacity of a thermal-electric power plant site.

The power plant designer today has the tools at hand which enable him to predict with an adequate degree of accuracy the effect of different stack heights on ground level concentrations of the gaseous pollutants emitted from power plant stacks. Use of tall stacks will make it possible in most cases to build larger power plants at any particular site than are in service now and still operate them satisfactorily from the standpoint of air pollution. On the other hand, atmospheric pollution considerations may make it necessary at some sites to put a finite limitation on the maximum capacity that can be installed.

International Bank for Reconstruction and Development

Lending OperationsThe International Bank for Reconstruction and Development made a loan on November 19, 1954, of $16.2 million to finance the foreign exchange costs of a thermal electric power plant in Bombay, India. The National City Bank of New York had agreed to participate in the loan without the Bank's guarantee to the extent of $1,364,000. The recipients of the loan, the Tata Hydro Electric Power Supply Co., Ltd., the Andhra Valley Power Supply Co., Ltd., and the Tata Power Co., Ltd., had already raised the equivalent of $6.2 million toward the rupee costs of the project ($11.3 million). The loan, which was for a period of 20 years, bore interest of 4¾ percent per annum, including the Bank's 1 percent commission.