Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2024Scopus SJRQ3/r/bayburt/13141
  Investigation of the Effects of a Self-Heated Vest on Vital Values of Individuals: A Case Study on Public Health

  Öztekin, Erman Kadir; Demirci, Emre

  With the adaptation of portable and harmless technological devices to clothing products, self-heating outdoor products are becoming more common in the market. These products can produce heat energy on their own, unlike standard thermally insulated products. In this way, it contributes to the thermal comfort of people in situations where the environment cannot be conditioned. In this study, the effects of these products, which are in close contact with the human body, on human health were measured through vital values. Measurements were collected from the same group of individuals at three different time intervals over 30 minutes. Significant differences between the obtained data were examined using the Friedman test and detailed using Wilcoxon Signed Rank test. While a significant difference was observed in systolic blood pressure, diastolic blood pressure and body temperature data, no significant difference was found in oxygen saturation and pulse data. As for the actual changes, no serious effects on human health were observed based on the vital values presented in the study.

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• MakaleAçık Erişim2024Scopus SJRQ3/r/bayburt/11873
  Thermoeconomic Analyses of Heat Pumps

  Öztekin, Erman Kadir; Gür, Mehmet Murat; Karaali, Rabi

  Recently, the rapid development of technology and the increase in energy costs and needs have made reducing the costs and efficient use of energy and exergy important. The thermoeconomic analysis method, which is the best cost analysis method of energy and exergy, gives the ways to reduce costs and increase efficiency that can be applied a facility. It has been found that the most suitable thermoeconomic solution for winter heating and summer cooling of a facility is a vertical underground source heat pump and the most high-performance working fluid that should be used is R32. If the heating is done with a ground source heat pump instead of electrical energy, 4.25 kW of heating energy will be obtained for each kW of electrical energy given for heating, since the costs are COPIP 4.25. Here the earnings increase by around 325%. In other words, heating costs decrease by around 77.5 percent, that is, from one hundred liras to 22. 5 liras.

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• MakaleAçık Erişim2024Scopus SJRQ3/r/bayburt/11590
  Exergetic Analyses of Detonation Engine Cogeneration Plants

  Çakmak, Bahar; Karaali, Rabi

  Efficiency improvements are very important in all research and technology. Detonation engines are high technology devices. In the last decades they attracted attention by many researchers. However, detonation engines for cogeneration are not researched efficiently. This article is about the detonation engines cogeneration cycles which analysed by using 1. and 2. law of thermodynamics and exergy analyses methods by the authors. The exergetic performance analyses, their advantage and disadvantages of the ZND-HRSG detonation engine cogeneration cycles were obtained. The exergetic performance analyses were done for various excess air rates to obtain the variations of the combustion exit pressures and temperatures, exergy efficiencies, electric heat rates, SFC and other parameters of their performance. Also, an optimization analysis was done for the ZND-HRSG by searching the optimum values for different excess air rates. The results showed that, the ZND-HRSG cycle have the optimum values of the performance at 1.6-1.8 of the excess air rates.

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  AtıfScopus1·OpenAlex5

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• MakaleYalnız künye2023/r/bayburt/12892
  Exergetic Analyses of Hypersonic Flows

  Topal, Esra Nur; Karaali, Rabi

  Hypersonic devices and vehicles and hypersonic flows are very important and competitive advanced technology in science and in the World. Hypersonic technology is rapidly spreading and turning into competition in developed countries, especially in space studies and defense industry. This technology is vital for developed countries. Because of shock waves emerging in hypersonic devices during hypersonic flow, the energy and exergy destructions they cause are the most important difficulties, obstacles and problems which arise in this vital technology. To overcome these problems and difficulties, to prevent or reduce or minimize energy and exergy destruction, aerodynamic analysis and energy and exergy analysis methods are applied. The data and the results that can be guiding and useful for the calculations and the design have been obtained. In this study optimal design and optimum calculations ways of the energy and exergy destructions of hypersonic devices and instruments are discussed. It is obtained and shown that how much exergy destruction and entropy production occurs at which altitude and hypersonic velocities and also at which oblique shock angles.

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• MakaleAçık Erişim2023/r/bayburt/12843
  Performance Analyses of Combined Cycle Power Plants

  Karaali, Rabi

  In this article, different compressor pressure and different excess air rates for a gas turbine based combine cycle power plant with steam Rankine cycle as bottoming cycle were analyzed by using 1. and 2. laws of thermodynamics and exergy analyses methods to obtain the best performances of the cycle. Exergy efficiency of the cycle, net powers of the gas and steam turbines and the overall cycle, exergy loss of the components, the efficiencies of the components are obtained, compared and discussed. It was found that, increasing the compressor pressure increases exergy efficiency of cycle, gas turbine and total plant power, and the combustion chamber, the HRSG and the compressor efficiencies. However, increasing compression rates decreases steam turbine power, combustion chamber, steam turbine, and HRSG exergy losses and the gas turbine efficiency. Also, it is found that, increases in excess air ratios gives an optimum or a maximum exergy efficiency, at 2.5 excess air rate of the cycle.

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  AtıfScopus3·OpenAlex6

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