Farklı soğutucu akışkanlar kullanan ejektörlü bir soğutma sisteminin termodinamik analizi

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Solar trackers and feasibility analysis of usage of solar trackers in electricity production in Konya, Turkey

World energy needs increases every day and it becomes more difficult to meet the energy demand of the growing population without harming the environment. Therefore, renewable energy is the main area of study for concerned researchers and scientists. Electricity production by using solar energy is one of the best alternatives to fossil fuels that lose its importance, due to rising costs and damage to the environment. The number of studies to advance the efficiency of solar systems increases day by day. Especially in electricity supply, usage of high efficiency solar energy systems can meet the expectations. At this stage, solar trackers that provide us efficient utilization of solar energy, gains importance. In this paper, working principles, usage advantages and economical contributions of solar trackers are discussed. Fixed systems, one axis systems and two axis systems are compared in terms of efficiencies and economic advantages. During this study, Photovoltaic Geographical Information System (PVGIS) is used for comparison between systems. It is obtained that solar power generation systems with solar trackers are more feasible than fixed systems

Comparison of Energy Demand Coverage with a CHCP Plant and a Convetional System: A Case Study for a Hospital in Konya, Turkey

Combined heating, cooling and power (CHCP) plants are one of the most efficient options for meeting the entire energy demand of humankind. Today, they are used very widely arround the world and the use of these has an increasing trend. High efficiency of CHCP plants help to reduce CO2 emmision and this make them environment friendly compared to other energy supply methods from fossil fuels. In this study, a comparasion of energy demand coverage of a commercial hospital located in Konya, Turkey with a CHCP plant and a conventional system which is installed now, is performed. The electrical load and heat load for both space heating and hot water were obtained by using real consumption data of the hospital for previous years. Economic analysis was performed, the feasibilty and enviromental impact of both systems are compared

Rule-based Mamdani-type fuzzy modelling of thermal performance of fintube evaporator under frost conditions

Frost formation brings about insulating effects over the surface of a heat exchanger and thereby deteriorating total heat transfer of the heat exchanger. In this study, a fin-tube evaporator is modeled by making use of Rule-based Mamdani-Type Fuzzy (RBMTF) logic where total heat transfer, air inlet temperature of 2 °C to 7 °C and four different fluid speed groups (ua1=1; 1.44; 1.88 m s-1, ua2=2.32; 2.76 m s-1, ua3=3.2; 3.64 m s-1, ua4=4.08; 4.52; 4.96 m s-1) for the evaporator were taken into consideration. In the developed RBMTF system, outlet parameter UA was determined using inlet parameters Ta and ua. The RBMTF was trained and tested by using MATLAB® fuzzy logic toolbox. R2 (%) for the training data and test data were found to be 99.91%. With this study, it has been shown that RBMTF model can be reliably used in determination of a total heat transfer of a fin-tube evaporator

Rule-based Mamdani-type fuzzy modelling of thermal performance of fintube evaporator under frost conditions

Frost formation brings about insulating effects over the surface of a heat exchanger and thereby deteriorating total heat transfer of the heat exchanger. In this study, a fin-tube evaporator is modeled by making use of Rule-based Mamdani-Type Fuzzy (RBMTF) logic where total heat transfer, air inlet temperature of 2 °C to 7 °C and four different fluid speed groups (ua1=1; 1.44; 1.88 m s-1, ua2=2.32; 2.76 m s-1, ua3=3.2; 3.64 m s-1, ua4=4.08; 4.52; 4.96 m s-1) for the evaporator were taken into consideration. In the developed RBMTF system, outlet parameter UA was determined using inlet parameters Ta and ua. The RBMTF was trained and tested by using MATLAB® fuzzy logic toolbox. R2 (%) for the training data and test data were found to be 99.91%. With this study, it has been shown that RBMTF model can be reliably used in determination of a total heat transfer of a fin-tube evaporator