No description available.

No description available.

No description available.

No description available.

Detta examensarbete syftar sig till att undersöka olika konceptuella lösningar utav en transmissionslina för ett vågkraftverk. De tre olika konceptuella lösningarna är; ett rep av materialet HMPE (High Modulus Polyethylene), en transmissionslina baserad på KONE Ultrarope samt en transmissionskedja baserad på elastomera lager. Dessa har indelats i nämnd följd enligt koncept A, koncept B och koncept C. Analysen av dessa grundar sig i befintlig information och kunskap. Från dessa koncept har sedan koncept A valts att studeras vidare för optimering, vilket gjordes genom bedömning enligt Pughmetoden. Verktyget Solid Edge har använts vid framtagandet av koncept A och B. Vid optimeringen för koncept A så konstruerades en trumma för att minimera nötning, maximera repets livslängd samt för att uppnå de satta kraven. / This bachelor’s thesis aims to examine different conceptual solutions of transmission lines for a winch-based wave power plant. The different concepts are; a rope of the material HMPE (High Modulus Polyethylene), a transmission line based on KONE Ultrarope and a transmission chain based on elastomeric bearings. These have then been divided in that order into concept A, concept B and concept C. The analyses of these are based on existing information and knowledge. From these concepts, concept A has been chosen to be further analyzed and optimized. Concept A was chosen by following the method of a Pugh matrix. The modeling software Solid Edge has been used when developing concepts, A and B. Concept A was optimized by designing a drum that minimize abrasion, maximize the life of the rope and was also adjusted for reaching the specific requirements.

American Electric Power's (AEP) coal-fired Clinch River Plant, a power-generating facility in Carbo, Russell County, Virginia (USA), has impaired Clinch River biota through toxic spills in 1967 and 1970, and effluent copper (Cu) concentrations that were reported to have exceeded water quality criteria from 1985-1989. These impacts have provided impetus for many research projects addressing the absence of bivalves, including federally protected species of native mussels (Unionoidea), from sites influenced by CRP effluent. Modifications in CRP effluent during 1987 and 1993 drastically reduced Cu levels and warranted the present study, which assessed long-term biological recovery in Clinch River biota near the CRP. In 2000-2001, surveys of benthic macroinvertebrate communities and instantaneous measures of effluent toxicity did not foretell significant reductions in survivorship and growth of field-caged Asian clams (Corbicula fluminea) at sites downstream of the CRP. More importantly, these results indicated renewed toxicity in CRP effluent. Additional transplant studies using two enclosure types were conducted to isolate effects attributable to CRP effluent from the potentially confounding effects of substrate variability among study sites. While it was found that mean growth of clams was greatest in the enclosure that minimized substrate variability (p=0.0157), both enclosure types clearly distinguished significant impairment of survivorship and growth at sites downstream of the CRP discharge, and strengthened the association between impairment and CRP effluent. An intensive field investigation was undertaken to determine whether impairment observed in transplant studies extended to resident bivalves. During 2001-2002, densities and age structures of C. fluminea and distributions of mussels suggested that impairment indeed extended to resident bivalves for a distance of 0.5 to 0.6 km downstream of the CRP discharge. Impairment of bivalves was less evident below (1) a fly ash landfill and (2) coal mining activities and low-volume leachate from a bottom ash settling pond. With respect to long-term recovery, modifications in CRP effluent treatment have reduced Cu concentrations from an average of 436 mg/L in 1985-1989 to 13 mg/L in 1991-2002. Subsequently, Cu body burdens of Asian clams (Corbicula fluminea) transplanted within CRP influence have decreased from 442% of levels accumulated at reference sites in 1986, to 163% of these levels in 2002. The reduction in effluent Cu largely explains recovery of most benthic macroinvertebrate community parameters (e.g., richness, diversity) at influenced sites from levels that were typically less than 70% of reference levels, to levels that frequently range from 80 to greater than 100% of reference levels. Nevertheless, bivalves remain impaired downstream of the CRP; survivorship and growth of C. fluminea transplanted to CRP-influenced sites have typically been less than 40 and 20% of reference values, respectively. Furthermore, C. fluminea has seldom been encountered within CRP influence for nearly two decades. Likewise, native mussels remain absent within CRP influence, but recent surveys suggest their downstream distributions are more proximate to the CRP discharge than has been reported previously. A preliminary assessment of factors potentially contributing to toxicity revealed that (1) water reclaimed from settling basins for discharge with CRP effluent significantly impaired fecundity of ceriodaphnids at concentrations of 50%, (2) LC50 values for industrial treatment chemicals were misrepresented on Material Safety Data Sheets and consequently, were subject to misapplication by operators, (3) Cu concentrations of 96 mg/L significantly impaired growth of Asian clams in artificial stream testing, and (4) effluent Al exceeded acute and chronic water quality criteria, suggesting this ion should receive further consideration in future studies. / Master of Science

Computational fluid dynamics was used to simulate solar chimney power plants and investigate modeling techniques and expected energy output from the system. The solar chimney consists of three primary parts: a collector made of a transparent material such as glass, a tower made of concrete located at the center of the collector, and a turbine that is typically placed at the bottom of the tower. The collector absorbs solar radiation and heats the air below, whereby air flows inward towards the tower. As air exits at the top of the tower, more air is drawn below the collector repeating the process. The turbine converts pressure within the flow into power. The study investigated three validation cases to numerically model the system properly. Modeling the turbine as a pressure drop allows for the turbine power output to be calculated while not physically modeling the turbine. The numerical model was used to investigate air properties, such as velocity, temperature, and pressure. The results supported the claim that increasing the energy into the system increased both the velocities and temperatures. Also, increasing the turbine pressure drop decreases the velocities and increases the temperatures within the system. In addition to the numerical model, analytical models representing the vertical velocity without the turbine and the maximum power output from a specific chimney were used to investigate the effects on the flow when varying the geometry. Increasing the height of the tower increased the vertical velocity and power output, and increasing the diameter increased the power output. Dimensionless variables were used in a regression analysis to develop a predictive equation for power output. The predictive equation was tested with new simulations and was shown to be in very good agreement. / Master of Science

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

Yes / Technological advancement on the electricity grid has focused on maximizing its use. This has led to the introduction of energy storage. Energy storage could be used to provide both peak and off-peak services to the grid. Recent work on the use of small units of energy storage like battery has proposed the vehicle to grid system. It is propose in this work to have energy storage device embedded inside the house of the energy consumer. In such a system, consumers with battery energy storage can be aggregated in to a community virtual power plant. In this paper, an optimized energy resource allocation algorithm is presented for a virtual power plant using genetic algorithm. The results show that it is critical to have a pricing scheme that help achieve goals for grid, virtual power plant, and consumers. / Mr. Oghenovo Okpako is grateful to the Niger Delta Development Commission of Nigeria for funding the work. The work has been also supported by the British Council and the UK Department of Business innovations and Skills under the GII funding of the SITARA project.