Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Mechanical Engineering


This investigation is to determine the amount of steam necessary to heat the buildings and to generate power on the campus of South Dakota State College. It is also concerned with a comparison of the cost of producing steam by burning coal and by burning natural gas. Part of the campus buildings are heated by low pressure steam. When the turbo-generator is in operation, the turbine exhaust steam is used for heating purposes. During periods of cold weather the turbine exhaust steam is not sufficient, and therefore steam at boiler pressure is reduced to the turbine exhaust pressure through a pressure reducing valve in the power plant. The piping losses of transporting this low pressure steam to the various buildings are greater than of transporting the steam at a higher pressure. It may prove desirable to supply smaller number of buildings with turbine exhaust steam and to raise the pressure in the remaining two pressure lines. During periods of warm weather the plant load is comparatively low and natural gas is a very convenient fuel to use. Should natural gas also prove to be a cheaper fuel, then there will be no question that its use will be continued and should be extended. At present only the largest boiler is equipped to burn natural gas and boiler efficiency decreases as the load decreases below rated output. Thus it may prove desirable to install gas burning equipment on a lower capacity boiler to gain the advantages of the perhaps cheaper, more convenient fuel and to operate at a higher percent of rated boiler output. Small steam turbines power various pieces of auxiliary power plant equipment. At present there is now way of knowing just how efficiently these units operate or what operating expenses are. A complete study of the entire power plant has never been made. The growth of the college and its annual fuel costs combined with the depreciated value of boilers, turbines, piping, heating, control and auxiliary equipment might make annual savings of several thousand dollars possible and justifies this study. Data on steam and power generated and fuel burned were obtained from metering equipment in the power plant. The results of this investigation could: (1) provide information relative to increasing the efficiency of the college power plant, (2) provide a basis for better estimating future steam requirements, (3) indicate the desirability of periodically testing fuel, (4) provide a better basis for future power contracts with the Bureau of Reclamation and (5) suggest desirable considerations.

Library of Congress Subject Headings

South Dakota State University
Heating -- Costs
Power-plants -- South Dakota -- Brookings


Includes bibliographical references



Number of Pages



South Dakota State University