Sharif Digital Repository

Rapid growing use of energy resources in recent decades, caused to focus on combined heat and power generation systems according to their high efficiencies. Energy efficiencies with these technologies will be up to 90 percent. Some benefits of Co-generation systems are their high efficiencies, omitting of transmission and distribution lossesin the electricity grid, fuel consumption reduction, moving to ward privatization,independent and decentralized production of electricity and heat, increase competition in the power generation and reduction theemission of greenhouse gases, particularly carbon dioxide. In This article theeconomicsof combined heat and power generator stobe installed... 

Increased exploitation of energy resources has led to growing attention to the CHP systems due to their high efficiency. High energy loss in power transmission network, which is about 20 %, is an additional reason for growing attention to CHP. In addition to that, utilization of small scale CHP systems has provided ground for growing competition with distributed generators based on renewable energy resources. Selection of optimal technology based on economical and environmental criteria requires application of analytical tool. An analytical tool could avail itself of identifying optimal program for operation of cogeneration systems. The present research work has been implemented to develop... 

In the present study, a heat recovery system for a distributed generation plant (DG) with a 1 MW gas combustion engine has been designed. The purpose of this designing is converting the power plant to a CHP system. For the existing heat recovery system, a shell & tube heat exchanger is designed to recover the thermal energy from exhaust gases and a plate heat exchanger is designed to recover the thermal energy from the engine jacket cooling fluid. The heat exchanger design has been calculated manually and also by use of software. In the software calculation, the heat exchanger design has been done by use of the Aspen HTFS +2006.5 software. In the manual one, the Kern equation (1950) was... 

Trends of energy consumption and global warming, air pollution, Greenhouse gas emission, depletion of fossil energy resourcec and the rise in costs of fossil resources, indicate that renewable energies are reliable alternative in energy supply systems. The purpose of the project is to investigate the contribution of renewable energy to meeting energy demand of housing units. Household energy system consists of various parts which do intreract with each other. Total household energy system may be represented with the help of reference energy system in order to consider the effect of changes in one part on the other sections. In this regard, the reference diagram of household energy supply... 

Cogeneration technologies such as Combined Heat and Power (CHP) have promising features for providing the electrical energy that various industries require while reducing the emissions and other environmental impacts of these industries. Investments in CHP systems require substantial implementation costs followed by a relatively long period of recovering the invested capital through savings in utilities bills. Appropriate timing of CHP system investments can reduce capital expenses and enhance returns on investments. An appropriate investment valuation method is needed to identify the appropriate time to implement a given CHP system and to find the values of properly scheduled investments.... 

Biomass's utilization provides sufficient energy which can be used for electricity generation, engine applications and etc. In gasitication process, biomass will be converted into clean and combustible gas in presence of steam and air. Biomass integrated-gasifier/gas turbine combined cycle (BIG/GTCC) systems are capable of producing up to twice as much electricity per unit of biomass consumed and are expected to have lower capital investment requirements per kilo Watt of capacity than condensing-extraction steam turbine (CEST) systems. In this Thesis thermodynamic analyses (both energy and exergy analyses) have been conducted for a combined cycle power plant, the investigated system... 

The rapid increasment of energy carriers and investment expenses in recent years, has increased the costs of energy demand and attracted those interested in consume reduction and efficiency using modern cutting-edge technologies. This research intends to design a general framework for optimization and energy and water demanding management studies in a sample region, regarding the new concept, energy hub.Thus as the first step, the existing industries and technologies with their thermal and electrical demands is considered as the first hub and wastewater treatment plant with its other equipments and thermal and electrical demands is considered as the second hub. The main issue in the modeling... 

Increasing demand, rising energy costs, and environmental concerns are some of the main challenges faced by the energy industry in upcoming years. With such a diverse set of issues, it is important to take a holistic approach to addressing these concerns and therefore transitioning to a smarter grid. Demand response (DR) has recently been introduced as a promising solution to these issues in the smart grid era. Since residential demand is a significant portion of the total system load, residential customers play critical roles in a proper implementation of DR programs. The main obstacle in broad implementation of residential DR is the low participation of customers in these programs. Lack of... 

Cogeneration or combined heat and power (CHP) which simultaneously produces electricity and heat energy from sequential use of single fuel source, has been introduced increasingly for industrial, commercial and residential applications due to its high energy efficiency. While the capital costs of CHP systems are comparatively higher than the conventional systems, their proper selection and optimal sizing and also optimal operation could result in shorter capital recovery period and lower cost of energy supply. Essentially the technical, economic and environmental performances of CHP system are closely dependent on its design and operation strategy. This project presents an optimization... 

The present study aims to reduce the carbon footprint of greenhouse products to provide a decision tool for sustainable development of greenhouses. In order to provide this decision tool, the impact of four scenarios or energy-efficient technology for greenhouse heating, including: combine heat and power system(CHP), new greenhouse covering material, industrial symbiosis, and solar collector on the carbon footprint of greenhouse products has been studied because one of the main factors in the release of carbon footprints of greenhouse products is the use of fossil fuels for greenhouse heating. Energy modeling has been used to estimate the amount of heating, cooling, and artificial lighting...