Sharif Digital Repository

In recent decades, due to economic, political and environmental issues, tend to use of the CHP systems (combined heating and power) have increased. CHP systems not only increase energy efficiency, but also decrease fuel consumption and emission levels of systems. The use of CHP technology in the industry has a long history, but the use of these systems in the commercial and residential sector, is considered, recently. As to the residential buildings, both electricity and thermal energy demands fluctuate seasonally and hourly, so it is necessary to take account of the plant’s annual operational strategies for the variations of load demands. In this paper, a nonlinear programming model is... 

increasing energy demand and emission of environmental pollutant as a result of using fossil fuels and increase in waste generated due to human activities resulted in considering this source as a partial substitute for fossil resources in power application . Hence in this project biomass is considered as source of energy for heat and power application. Having low quality energy is the most important difficulty for application this resource as an energy carrier, so, gasification is applied to convert this source to gas with higher quality one. Produced gas in gasification enters to a micro turbine to meet thermal and electrical demand of the Sharif energy research institute. To investigate... 

In this project, a co-generation system with the operation capacity of less than 1000 kilowatts has been studied. The main purpose of this project is to help decision makers in order to choose proper combination of micro turbines and/or reciprocating engines, with certain rating capacity, as the prime movers of this co-generation system. Some factors that have been considered in the decision making process are prime mover operation in various ambient temperatures, various altitudes and part-load conditions and also operational restrictions such as power to heat ratio, maintenance cost ratio and prime movers plant factor and also economic characteristics such as investment and operating cost... 

Overall performance improvement of gas turbine is available by modifying each component of cycle. The purpose of this research is to improve performance of a micro turbine with 200 KW power, by redesigning compressor set. Considerable increase in performance and stability occurs, by adding individual stage of axial compressor at the entry of centrifugal section. It should be noted that, this improvement occurs without a significant increase in size and without having to change the centrifugal compressor design.In this study, design of one stage axial compressor and three dimensional modeling is discussed after, modeling and preliminary design of centrifugal compressor. Then, after obtaining... 

Nowdays much of the organic solid waste and wastewater is buried using centralized and traditional methods. This leads to many problems, including groundwater pollution, methane emissions into the atmosphere and rapid transmission of disease. In order to avoid these problems, using a decentralized approach can be a good solution. In this study, recovery of organic waste and wastewater of residential buildings using anaerobic digester as a decentralized way, have been examined. Using experiments, the optimum mass ratio of organic solid waste and wastewater is obtained as 80% and 20% respectively. Biogas production model is developed using mass balance and Balance of electrons in redox... 

Due to the growth of energy consumption the use of new technologies and efficient energy conversion is necessary. An example of efficient energy conversion technology is CCHP (Combined Cooling, Heating and Power). The aim of the present research work is to develop a model that could be applied for optimal design of a hybrid CCHP system which would be Solar Combined Cooling, Heating and Power (SCCHP). In order to do so,microturbine power system, cooling and heating equipment’s such as absorption system and heat exchanger and also solar collector have been considered as an integral part of the system. The objective of the application of the model has been to identify proper sizing of all... 

Hybrid Solid Oxide Fuel Cell-Micro Gas Turbine systems(SOFC-MGT) present opportunities for improvement over conventional systems, including high efficiency, cogeneration, and the potential for low carbon emmisions. In order to advance toward commercialization, Hybrid systems need to model under design point and off-design situations that maintain safe and efficient operations, also exhibiting favorable exergetic and economic performance. The present work investigates the hybrid SOFC-MGT performance and effects of steam injection, humidity effect, and fuel change in the system. The 1-D model of SOFC stack has been developed in EES Code and then coupled with a microturbine’s components with... 

With the growing development of urban communities and population, the demand for water and treated sewage water has grown significantly. The environmental damage of polluted water has resulted in passing of new and strict environmental laws on wastewater discharge recently. In the present research, a hybrid system involving a power, heat and cool cogeneration and a carbon dioxide capture system has been designed for a typical wastewater treatment plant. The plant is optimized from economic and environmental criteria. The anaerobic digester is modeled using the ADM1 model. The biogas is directed into the hydrogen sulfide removal filter to remove the impurities and into the heat exchanger to... 

The increasing need for more efficient and environmentally friendly microturbines necessitates the utilization of compact recuperators resulting in lower fuel consumption and emissions. The goal of this research is to determine the performance behavior of a primary surface recuperator to be incorporated in a 100 kW microturbine. Primary surface recuperator, known for relatively favorable characteristics in heat transfer, low weight, and high efficiency is considered as a candidate in aviation engines. In this research, a computational model for heat transfer and pressure losses is used for the design optimization of annular involute-profile cross wavy primary surface recuperators in... 

It has been well documented over the years that axial and radial inflow turbines have traditionally been the solutions of choice for organic Rankine cycles. Recently, the advantages of radial outflow turbines in various operating conditions of the organic Rankine cycle have been highlighted. However, no research has been done on the use of this type of turbine in other cycles and for relatively high cycle pressure and temperature conditions. Further, there is no information on the design process of radial outflow turbines in the open literature. The purpose of this research is to compile a relatively accurate process of designing a radial outflow turbine and the feasibility of using it in a...