Sharif Digital Repository

Analysis of energy flow which effectively leads to reducing energy consumption in buildings is of major importance. The following research is the development of methodology and simulation of energy in the residential buildings and realization of the methods by means of FORTRAN software. In the process of modeling energy flow, in order to evaluate thermal comfort and calculate building’s thermal load, the dynamic and integrated interaction of these parameters must be appraised. The continuous and integrated study required that Mass and energy flow, for various component of building, and their interaction be examined. These factors could not be assessed using simple and reliable methods. In... 

The purpose of this project is choosing optimal technologies of cooling and heating and production of usable hot water and also to use optimal thicknesses of heat isolating walls, roof, floor and heat isolating of hot water transfer piping that is done to minimize the expenses of technology, energy and maintenance of the technology. We did all of the above mentioned issues by depicting the energy balance. In this modeling, we first defined four scenarios. Then by using a linear mathematical model of integer, the optimum number of lamps selected in accordance with the standard lighting. In the next step, by using a nonlinear mathematical model, we defined the optimal thicknesses of insulators... 

Gas turbine is one of most widely used in power plants to generate electricity or mechanical power options in the industry , which is having its own advantages and disadvantages . if the turbine use simple , efficiency is generally below 33%. . After installing and employ , these turbines produce efficiency less than their nominal amount . The methods no change in structure exist that increase the efficiency or power of the turbine to acceptable level .In this thesis, gas turbine and to improvement performance methods has been studied . gas turbine with the methods are simulated to obtain the effect of each method in different environmental conditions . Economic sensitivity analysis... 

In the building, can be used variaty of Heating, Ventilating and Air conditioning systems. Among the items that affect to select the hvac system can be pointed to building thermal demand and system energy consumpsion. simulation of this systems is one of the ways that can compare hvac systems in the building. according to Iran needs for preparation of software for optimization of energy carriers consumption in building proportional with existing matrials and equipment in the country, in this research has been tried methodology and modeling of hvac systems in the way developed that producted software is capable simply and practical for engineers be operational in a residential unit. In realy... 

Increasing population and rapid industrial development has resulted in increasing energy consumption exponentially. Limited resources of fossil fuels have forced industrialized countries to reduce energy consumption by modern systems as much as possible.
Poultry farms consume about 1,400 million liters of gas oil per year and 38% of total consumption in the agricultural section; then they are the largest consumer of this industry in Iran. Unfortunately traditional heating systems and poor control of indoor conditions are some of the most important factors affecting energy consumption in poultry farms. With the air ventilation rate of a salon equal to the amount of air needed for birds up... 

Overpressure protection and flare loading network are critical challenges faced by the Oil & Gas and chemical industries. Whether they are new facilities or aging ones, integrity management of overpressure and flaring systems remain significant throughout the life of the planet. One of the most important ways for protection of over pressure and depressurizing to flare header through pressure safety valve is implementation of safety instrument system (SIS). Application of safety instrumented systems for the process industries causes significant reduction of flaring load and loss prevention of valuable materials through increase protection layer availability and over pressure risk reduction.... 

By growing the global demand for energy and use the fosil fuel for it by knowing the issue of increase in their resourses؛ it’s important to use new technologies for these energies in an optimum way.
Most of industrial process uses a lot of thermal energy by burning fossil fuel to produce steam or heat for the purpose. One of the most important processes that use energy is refrigeration. After these processes, heat is rejected to the surrounding as waste. This waste heat can be converted to a useful refrigeration by using a heat operated refrigeration system, such as an absorption refrigeration cycle. This can be a useful pattern to improve thermal efficiency of process and reduce its... 

The role of natural gas compressor stations, is to maintain the gas pressure at the level required for gas transportation along the pipeline to the distribution system. In Iran, residential heating demand, has a large share in natural gas consumption. Thus the demand of natural gas would be greater in cold winter days in comparison to other seasons. Due to this intense demand fluctuations, geographical diversity of demand, long distances between supply and demand points, supply and demand mismatches and long term investment, there is an intense reliability and load factor issues within these systems operations. In this thesis, natural gas compressor stations are modeled and installation and... 

In 2023, global gas flaring at upstream oil and gas facilities reached its highest level in the past five years, with a 7% increase compared to the previous year. Iran, which is the second-largest flare of gas in the world after Russia, saw the largest increase globally, with a 19% rise in flaring volume. On the other hand, while offshore fields have accounted for about 12% of Iran's total oil production over the past decade, these fields have contributed to nearly 40% of the country’s total gas flaring. This study explored the feasibility of four methods for recovering flared gas from Iran’s offshore fields, including: transporting flared gas to land for sale as raw gas, transporting it to... 

Distillation is the most applied unit in the separation processess of the oil and gas industries. Because the distillation process requires energy in the form of the utilities, integration of heat pump systems in the distillation process as an application of these systems is considered in this research. A new and effective methodology of proper integrating of heat pump and distillation columns has been proposed by collecting thermodynamic and thermoeconomic tools. Then, this procedure has been applied on the ethane recovery and NGL fractionation units of 4 & 5 phases of the south pars field. The exergy analysis of the distillation columns is the first step of this methodology as the... 

Incereasing trend of energy consumtion and limited sources of conventional energy carriers causes an increase of carrier’s price and as a result nowdays more attention is focused on unconventional energy carriers. One of these unconventional carries is flare gas, which has a high potentioal for recovery.There are different methods for flare recovery and electricity generation is one of the most economic solutions for flare gas. The purpose of this project is technical and economical investigation of electricity generation using flare gas and to study impact of important parameters on economy of design. Reciprocationg engin, gas turbine and steam turbine are chosen for investigation. Capital... 

Using of physical safety devices such as pressure safety valves, are the most conventional methods to protect vessels against overpressure but operation of these devices have many negative effect on environment also they waste significant amount of valuable hydrocarbon materials. Relying on conventional safety devices needs a flare net to send excess gas to torch and in many cases essential equipments for flare net is so expensive and their maintenance are difficult thus reducing the size of flare net for a chemical plant is beneficial.
Application of new alternative device (HIPPS) is very helpful to reduce flaring load and releasing pollutant materials such as SOx and NOx. The main... 

Hybrid vehicles have many advantages, including reducing greenhouse gas emissions, saving fuel, and optimizing energy use. Proper routing for hybrid vehicles can improve fuel efficiency, increase energy efficiency, and even extend the life of electric batteries. In this study, two routing modes, offline and online, are introduced. The offline mode guides the vehicle from the starting point to the destination by using satellite traffic data and geological information such as slope information. In the online mode, the vehicle, with the ability to receive signals from surrounding vehicles (V2V), such as a breakdown of the vehicle in front, and considering concepts such as traffic, the presence... 

According to the Government policy in order to make targeted subsidies and apply it on various sectors in the industrial, commercial, agricultural, household and etc. changes in the energy supply needed resources in this section are required to appear. The agriculture sector is one of the most important parts of the food production is the production of security and health product. In this regard, the production of greenhouse products in terms of the use of high yielding varieties, production of the off-season, better control factors in production and reduce water consumption has increased drastically. The main source of supply in the internal energy of the greenhouse heating is mainly fossil... 

Dish-stirling system with an efficiency of nearly 30% is the most efficient technology among solar energy technologies. This system includes four main parts; Parabolic dish, solar tracker, receiver and Stirling engine and generator. In this system, first parabolic dish concentrates sun rays on its focus. A receiver is put on the focus to receive the heat radiated from dish. This receiver transfers the heat to a Stirling engine. In Stirling engine, expansion and contraction of gas helps piston to move and finally rotational mechanical work is done. With coupling a generator and Stirling engine we can generate electricity. Also for keeping the focus of sun rays on receiver we should have sun... 

In this research convective heat transfer coefficient enhancement of nanofluids prepared from high surface area graphene has been investigated in laminar flow in the developing region. The nanofluid has been prepared from nanoporous graphene with high surface area and with concentration of 0.025 to 0.1 %wt. Deionized water has been used as the base fluid and a type of Ter-Polymer has been utilized as the surfactant. The results indicate that thermal conductivity of nanofluid with concentration of 0.1 %wt remains quite constant, with only %3.8 enhancement, while convective heat transfer coefficient improves significantly, with 34% enhancement. The behavior of this enhancement related to the... 

Low effiencies of equipments and lack of forecasting heat integration in some oil regions are the reasons of primary energy losses in these regions. Also there have been difficulties in providing electric power demands in regions separate from the state electricity network which is a barrier in front of exploiting all the potentials of the region. This research introduces a model that can lead to selection of optimal configuration of equipments and units in order to establish a CCHP system that answers variable electric, heating and cooling demands ensuring a safe margin of power generation. The model simultaneously has the ability to select between existing and new installable equipments.... 

This study is a modeling for “building’s energy consumption” as well as selecting an optimum composition of technologies to meet a building’s needs, with an approach of reducing energy and facility costs . In modeling the energy stream to evaluate heating comfort and to calculate building’s heating load, the interaction between these two phenomena is assumed to be en block. The unique and en block study requires surveying mass and energy streams from all particles of a building, which are not traceable in simple static methods. This study assumes a building with following requests: heating load, cooling load,air conditioning and heat water. An optimum selection of facilities and... 

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... 

This research presents technical and economical feasibility study of using solar assisted ground source heat pumps (SAGSHPs) in different climatic zones of Iran. In order to evaluate technical and economical parameters of SAGSHPs, Iran is divided in to six main climatic zones including Tehran, Tabriz, Yazd, Rasht, Bandar abbas and Ardabil. Cooling and heating demands for a 1000 m2 residential building is calculated for each city, using modified bin method. Then a technical model has been developed by MATLAB software in order to evaluate systems optimal scale for supplying energy demands in each city. An economical model has been developed as well, to evaluate system’s annual energy savings...