Energy-environment-city triangle

WOS: 000221186100008Turkey has dynamic economic development and rapid population growth. It also has macro-economic, and especially monetary, instability. The net effect of these factors is that Turkey's energy demand has grown rapidly almost every year and is expected to continue growing, but the investment necessary to cover the growing demand has not been forthcoming at the desired pace. On the other hand, meeting energy demand is of high importance in Turkey, but exploiting the country's large energy efficiency potential is also vital. Air pollution is a significant problem and, as the government's projections show, carbon emissions could rise sharply if current trends continue. In this study, concepts of city, environment and energy are considered together and the issue how a city should live is examined, solutions are proposed, and the duties of the individual and of the foundations are dealt with

An investigation about the relations between the results of heat conduction problems with and without phase change

WOS: A1996VB93500014There are physical relations between the velocities of the isotherms for two heat conduction problems having the same initial and boundary conditions, but one of them has phase change while the other one has not. The main idea of this study is to find these relations mathematically, which stand on a physical base, depending on the physical properties of the phases and the common parameters of these two different problems. If such kind of relations are known, then it will be possible to find the position of solid-liquid interface by using the analytical solutions and the relation itself, not solving the phase change problem. This idea is applied to heat conduction problem in semi infinite media and one dimensional phase change problem is solved for three different kind of boundary conditions via the Enthalpy Method. The results are correlated with the analytical solutions of the problem having same geometry and conditions but without phase change and obtained some relations having correlation coefficients changing between 0.91 and 0.98. This result shows that the regression analysis made is statistically meaningful

EXERGETIC ANALYSIS OF A SOLAR ENERGY-BASED HYDROGEN PRODUCTION SYSTEM

23rd World Hydrogen Energy Conference: Bridging Continents by H2, WHEC 2022 -- 26 June 2022 through 30 June 2022 -- 186176BAU;et al.;INOGEN;Republic of Turkey, Ministry of Energy and Natural Resources;TENMARK;Turkish AirlinesIn this study, energy, exergy and sustainability analyses are performed for a solar energy-based hydrogen production system, which is modeled with TRNSYS and Engineering Equation Solver (EES) software packages. This system consists of solar photovoltaic panels (PVs), a controller, an electrolyzer, a metal hydride hydrogen tank used for hydrogen production and storage, and Proton Exchange Membrane Fuel Cell (PEMFC) for electricity storage. Dead state temperature is taken as 0 ºC. The results revealed that the PEMFC had the highest energy efficiency of 53.28%. Exergy efficiencies of the solar PV panel, the electrolyzer and the PEMFC were determined to be 9.66%, 60% and 29.39%, respectively. The exergetic sustainability index of the electrolyzer had the maximum value of 2.501. © 2022 Proceedings of WHEC 2022 - 23rd World Hydrogen Energy Conference: Bridging Continents by H2. All rights reserved

Renewable energy effect in a building heating system

Hong Kong Control Engineering and Information Science Research Association;International Frontiers of Science and Technology Research AssociationInternational Conference on Frontier of Energy and Environment Engineering, ICFEEE 2014 -- 6 December 2014 through 7 December 2014 -- 113929This study deals with performance of net zero energy building and comparable energy/ exergy analyses. Heating energy system is investigated from the primary energy production to the building envelope. As a building, a two story detached house located in İzmir, Turkey, is considered for the analysis. Energy and exergy analysis methods, which are based on the lowex (low exergy) method, are performed to evaluate their energy performances and compare them through energy and exergy efficiencies. For heating applications, three options are studied, namely (i) standard boiler, (ii) condensing boiler, (iii) solar collector as driven by renewable and non-renewable energy sources, to determine energy consumption of the detached house. For the detached house with a net area of 526.8 m2, solar collectors provide almost 31% more primary energy savings than standard boiler. The total exergy efficiencies of considered heating systems also are 3.4%, 4.0%, and 25.7% respectively for three cases. © 2015 Taylor & Francis Group, London

Thermoeconomic Analysis of a Mobile Air Conditioning Unit Using the Specific Exergy Cost (SPECO) Method

2019 International Conference on Environment, Resources and Energy Engineering, EREE 2019 -- 9 October 2019 through 11 October 2019 -- -- 159043In recent years, many researchers have used exergy-based analysis and assessment methods such as exergy, exergoeconomic and exergoenvironmental as powerful tools to solve practical problems in the design and to improve energy-related systems. The main objectives of this contribution are to analyse and assess the performance of a mobile air conditioning (MAC) system from the thermoeconomic point of view that combines energy quality and economic issues. We used the specific exergy cost (SPECO) method to calculate exergy-related parameters and display cost flows for all streams and components in the whole system. In this context, we considered a vapour compressed MAC unit (utilizing R134a as a refrigerant) of a public bus with a capacity of 99 passengers and a volume of 69 m3. In the analysis, we utilized the real data obtained from the measurements. Based on the exergetic analysis, while the highest exergy destruction rate was determined to be 3.7 kW for the compressor, with a minimum value of 0.15 kW due to the condenser unit. Furthermore, through the SPECO method, the highest and lowest exergoeconomic factors belonged to the condenser with 0.63 and the expansion valve with 0.05, respectively. © Published under licence by IOP Publishing Ltd

Environmental Impacts from the Solar Energy Systems

WOS: 000261189000004Solar energy technologies offer a clean, renewable, and domestic energy source, and are essential components of a sustainable energy future. Solar energy systems (i.e., photovoltaics, solar thermal) provide significant environmental benefits in comparison to the conventional energy sources. It is known that these systems have some minor negative impacts on the environment during their production and operation. This study presents an overview of some positive impacts of the solar energy systems and negative impacts covered by environmental impact assessment