This investigation was conducted to determine the indicated annual savings which could be expected from the proposed installation of a 5000 Kw turbo-generator unit in the Virginia Polytechnic Institute Heating and Power Plant. These savings were determined by comparing three proposed plans of generating or purchasing electric power while supplying the college with steam. The daily log sheets and flow meter charts of the plant were used to determine the electric load curves and the steam demand curves for the year 1952. These curves were projected into the future to include the years, 1956, 1957, 1958, and 1959. These curves, together with performance curves for a 5000 Kw three stage extraction condensing turbo-generator were used in the investigation. The average outdoor temperature days were grouped in 5°F increments from 20°F through 70°F. A set of four daily load curves was plotted for each 5°F increment. Curve No. 1 shows the total electric load on the system. Curve No. 2 shows the steam demand on the plant when the proposed 5000 Kw three stage extraction condensing turbo-generator is carrying the total electric load while extracting the heating and process steam. Curve No. 3 shows the electric power that the proposed 5000 Kw two stage extraction back pressure turbo-generator would generate while meeting the heating and process steam demand. Curve No. 4 shows the total heating and process steam demand. The area under curve No.1 represents the total electric load in kilowatt-hours on the system for a day. The area under curve No. 4 represents the total heating and process steam demand in pounds for a day. The daily cost of plan No. 1 was obtained by multiplying these areas by their respective scale constants and then adding these products. The area under curve No. 3 and under curve No. 1 where curve No. 1 is below curve No. 3 represents the electric power in kilowatt-hours that could be generated by the proposed back-pressure unit. The daily saving of plan No. 2 was determined by multiplying this area by its scale constant. The daily cost of plan No. 2 was obtained by subtracting this saving from the daily cost of plan No. 1. The area under curve No. 2 and curve No. 4 where curve No. 4 is above curve No. 2 represents the steam demand in pounds for a day of the condensing unit carrying total electric load while extracting the heating and process steam. The daily cost of plan No. 3 was obtained by multiplying this area by its scale constant. The daily saving obtained by using the extraction condensing turbine over the plan of purchasing all the electric power was determined by subtracting the daily cost of plan No. 3 from that of plan No. 1. The daily saving obtained by using the extraction condensing turbine over the back-pressure turbine was determined by subtracting the daily cost of plan No. 3 from that of plan No. 2. The yearly costs and savings were determined by multiplying the daily costs and savings by the number of days in each group of average outdoor temperature days and adding these products. The expected yearly saving of plan No. 3 over plan No. 1 for 1956 would be $137,400.00, for 1957, $147,600.00; for 1958, $158,000.00 and for 1959, $171,300.00. The expected yearly saving of plan No. 3 over plan No. 2 for 1956 would be $64,300.00; for 1957, $73,200.00; for 1958, $79,900.00 and for 1959, $93,300.00. / Master of Science

This investigation was conducted to determine the indicated average heating season saving which could be expected from several different size turbines with different throttle conditions and varying stages of feedwater heating when operating in the Virginia Polytechnic Institute Central Heating and Power Plant. Such a saving in cost of power produced locally is possible because of the higher cost of power when purchased from the Appalachian Electric and Power Company. This investigation covers the heating season of 1966-1967, and assumes that the present turbo-generators will not be in use at that time. The electric load and steam demand load for the average heating season day of 1952-1953 were taken from existing records and were projected into the future to the heating season of 1966-1967. Two values were used as factors to project the steam demand into the future because of the uncertainty of the future college expansion. From this data electric load versus time curves and steam demand versus time curves were plotted for the average heating season day. This information, together with steam rates and exhaust rates for one, two, and three stage feedwater heating cycles for each proposed turbo-generator unit was used. Four curves were plotted for each throttle condition for the average heating season day in order to determine the kilowatt hours which could be generated by each proposed unit of sufficient size to supply the expected future steam demand. These curves were: Curve No. 1, the expected total electric load; Curve No. 2, the expected electric power generated by the proposed unit with one stage feedwater heating; Curve No. 3, the expected electric power generated by the proposed unit with two stage feedwater heating; Curve No. 4, the expected electric power generated by the proposed unit with three stage feedwater heating. The areas under curves two, three, and four represent the kilowatt hours which could be generated by the proposed unit supplying the expected steam demand. The value of these areas in terms of dollars saved was determined by multiplying the areas, in square inches, by a scale constant, 1000 Kw-hrs per square inch, and by $0.008 per Kw-hr minus the fuel cost per Kw-hr. The value $0.008 is the minimum rate of energy paid by the college for purchased power from the Appalachian Electric Power Company. The resulting figure represented the average daily saving for the heating season. This figure was used to calculate the total saving for the heating season. The indicated savings which might be expected for the heating season of 1966-1967 ranged from $89,000.00 for a throttle condition of 250 psig. and 500 F and a 3750 Kw unit with one stage feedwater heating to $249,480.00 for a throttle condition of 1200 psig. and 950 F and a 9375 Kw unit with one stage feedwater heating. The results for each throttle condition and turbine with varying heater stages are tabulated in part C of the investigation / Master of Science