Final presentation design project 1
- 2. Outline Introduction Constrains Electricity demand/supply Classification Measurable performance indicators Design model Main parts of design model Transmission of electricity Costs Social, economic and environment requirements Life cycle system Conclusion Reference
- 3. Introduction This System Design Document has been created to outline the proposed system design for new geothermal power plant in Savusavu. The new system is intended for the production of electricity from the geothermal station for the consumers of Vanualevu hoping to get a clean and renewable energy. The new system design indented to be build is the binary power plant, it will replace the fossil fuel driven generators 20 to 50 MW of power would be produced in a renewable manner. The binary power station would require the brine or the aquifer at 70-200 degrees Celsius. The binary cycle power plant has one major advantage over flash steam and dry steam power plants: The water-temperature can be as low as 57°C (135°F). The water coming from the geothermal reservoirs through the production wells is never in direct contact with the working fluid. After the some of its thermal energy is transferred to the working fluid with a heat exchanger, the water is sent back to the reservoir through the injection wells where it regains its thermal energy.
- 4. Introduction (cont.) These power plants have a thermal efficiency rate of only 10-13%. However, geothermal binary cycle power plants enable us, through lowering temperature requirements, to harness geothermal energy from reservoirs that with a dry- or a flash steam power plant wouldn’t be possible. Looking at the number of people living and demand for power in Vanua Levu, it is less when compared to the demand of power in Viti Levu. Nevertheless the population size in Vanua Levu is small but there is need for the people in Savusavu to access electricity with minimum cost and reliable energy source for reducing the consumption of fossil fuels. Therefore, geothermal is a renewable energy source which can reduce the emission of carbon dioxide into earth’s surroundings and can minimize the cost to make people in Savusavu Area get access to electricity. Furthermore, to represent an engineering design of a model, each and every components of the system should be considered and gathered information about each parts in order to know the function of each components in the system. As stated above, we will design the model of Binary power plant for Savusavu Area in Vanua Levu. Therefore, different parts of this system will do different works starting from extraction, power conversion, power transmission/transportation and delivering of power to customers.
- 5. Constrains The people of Vanualevu demands a stable electricity supply that is cheap and clean to use. A renewable energy system that is safe and provides electricity to the people of Savusavu The best energy system that can be used in Savusavu is geothermal energy system.
- 6. Electricity demand Fossil fuel power source Replacing as geothermal energy system Power station Power source CAPACITY (MW) Savusavu Binary geothermal plant 80 *250KW Three phase induction type genertors TOTAL 20
- 8. Classification of geothermal energy towards clients Resources classification is a key element in the characterization, assessment and development of geothermal energy. Stakeholders at all levels of government, with in the geothermal industry, and among the general public need to be able to use and understand consistent terminology regarding issues such as location, quality, feasibility, of development, and potential impacts. Terminology must encompass both the geothermal nature of geothermal resources and the practical technological and economic aspects of resources exploitation while reaming understandable to the broad community of non-specialists.
- 9. Environment measurable performance indicators Its provides information that helps evaluation and decision making within organizations that engage in environmental efforts. Provides a common foundation of information for organizations and external interested parties ( such as consumers, business, partners, residents in local communities, shareholders and financial institutions) and their environmental efforts. It also provides a common foundation of information that helps the integration of environmental policies of the national and local governments, such as basic environment plans and environmental activities of organization.
- 10. Geothermal power plant model One company that can supply this type of power plants is FUJI ELECTRIC LTD
- 11. Working fluid, Cooling fluid, Geothermal brine The two working fluid primary and secondary are brine and n-pentene. In the selection of working fluid, It was ensured that the thermal characteristic satisfied the binary working conditions. There was less adhesive effect on the environment. The heating of the working fluid was easy The properties of the liquid are equal.
- 12. Evaporator functions details Function is to heat the working fluid after being heat by the Preheater item Major features evaporator type Horizontal shell-and tube type capacity 1990KW Temperatur e inlet/outlet N- pentene84/ 105*C Brine 130/130*C
- 13. Preheater functions details it heats the working fluid. Purpose to heat the n-pentene. Item Major features preheater Type Horizontal shell-and tube type Capacity 720kw Temperatur e inlet/outlet N-penten 36/84*C Brine 130/100*C
- 14. Turbine Turbine used in this binary cycle system is radial inflow with a diameter of 448 mm of rotor, amount of rotor 110 pieces blades, nozzle length 35 mm, diameter 20 x 6 mm nozzle, nozzle material is AISI 304, the number of nozzle 6 pieces, with double mechanical seal of material stainless steel, tungsten and carbon with gear box ratio is 4 : 1.
- 15. Condenser Condenser has the function to cool the working fluid that comes out of the turbine so that it returns to the liquid phase.
- 16. Generator The turbine that is turn by the secondary liquid is connected to the generator. There will be 80 generators with each capacity of 250kw
- 17. Other parts include The injection well-cooled brine is pumped into the geothermal reservoir The production well-heated brine is pumped out from the reservoir.
- 18. Transmission of electricity The 20MW power will be supplied to the consumers by electric transmission cables by the help of transformers electricity will supplied to every household and industries.
- 19. Cost Direct use of geothermal energy is a absolutely cheaper than other energy sources. Cost of electricity generation depends upon certain factors. 1. Temperature and depth of resources 2. Type of resources ( steam, liquid, mix) 3. Available volume of resources 4. Size and technology of plant The initial investment is high But after certain time period , the cost of electricity becomes comparable to other resources of energy.
- 20. social requirements of geothermal energy Expectations of local communities, governments, development organizations, nongovernmental organizations (NGOs), and other stakeholders have risen significantly regarding how effectively companies should mitigate environmental impacts of their activities. These expectations have been explicitly expanded to include social issues and impacts, which are often not seriously discussed in environmental impact assessment reports. In developing countries, expectations have been made complex by the challenges associated with sustainable development. To meet these challenges, governments through their legal systems must develop regulation on creation of a level field for industrial competition and investment without jeopardizing the needs of the local communities and other affected parties.
- 21. Economic requirements of geothermal energy Marketing analysis – size of market, distribution, market segments Design costs – design team computing, information retrieval Development costs – design detailing, supplier costs, testing costs Manufacturing cost - tooling, labor, overhead, assembly, inspection Distribution costs - packing, transport, service centres, spare parts, warranty Resources – time, budget, labor, capital, machines, material
- 22. Environmental requirements of geothermal energy Compatibility with other land-uses. Geothermal power plants require relatively little land. The installations don’t require damming of rivers or harvesting of forests, and there are no mineshafts, tunnels, open pits, waste heaps or oil spills. They can be sited in farmland and forests and can share land with cattle and local wildlife. Renewability of the resource. Geothermal energy has been classified under clean and renewable resource. The resource can be described as renewable only if the rate of extraction is less than the recharge rate. Sustainable use of the resource can be attained through reinjection and reservoir flow monitoring.
- 23. Life cycle costing of the system The total amount of installing the system would be close to 50 million dollars, which will take 2.5 million per MW. The aim of achieving this 50 million would take approximately 30 years, with 149000KWh of electricity 55240000 dollars of electricity would be sold. The maintenance and operation will cost 2762000 dollars. So at this at a breakeven rate of sale of electricity at 0.12dollars/kWh would give back 15145000 dollars for the life cycle cost of this geothermal power plant system.
- 24. Conclusion Geothermal heating system can be replace fossil fuel heating system in a particular area. Annual costs for common heating purpose can be reduced by more than 60%. Continued energy shortages have created added interest in geothermal energy for power generation. Geothermal energy appears to be a partial solution to our energy needs.
- 25. Reference www.worldenergy.org www.NEED.org www.wikipedia.com Google maps Energy department of Fiji Fuji electric LTD
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