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Turkish Journal of Energy Policy
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This is an Open Access Journal

Open Access journal
ISSN (Print) 2602-4659
Published by DergiPark

[185 journals]

Model of the combi boiler appliance in TRNSYS for domestic hot water
circuit: Experimental and numerical validations of economic mode
simulations
- Authors: Okan GÖK; Ayşe Uğurcan ATMACA, Hürrem Murat ALTAY, Aytunç EREK
  Abstract: Combi boiler type heating appliances are used nearly in every residential building for both space and domestic hot water (DHW) heating functions. There are challenging targets regarding both of these functions. Since there is a huge laboratory testing procedure behind each appliance design and the structural or operational changes on the regular designs, simulation models could be established for the initial evaluations of the appliance testing. Therefore, due to the estimations from the preliminary results of the simulations, the number of the laboratory tests could be decreased with cost, time, and energy savings. In this study, the main objective is modelling DHW heating circuit of a combi boiler appliance with the help of Transient System Simulation Tool (TRNSYS 18) to calculate DHW outlet temperature under various operating conditions. The TRNSYS model is validated experimentally and compared with the previous works of the authors. A good agreement is achieved in both transient and steady-state regions and the TRNSYS model is found superior when compared to the previously established one-dimensional model of the authors. DHW circuit model is validated only for economic (eco) working mode simulations in this study. Mean absolute error (MAE), mean square error (MSE), and root mean square error (RMSE) values are compared for the outcomes of the previously constructed one-dimensional model and currently established TRNSYS model with reference to the experimental data. TRNSYS model decreases all of these errors calculated according to the overall temperature profiles including the transient region for the central heating water at the heat cell inlet, central heating water at the heat cell outlet, and the inlet and outlet temperature difference of DHW at the experimentally investigated DHW flow rates of 5 l/min, 7 l/min, and 8.7 l/min.
  PubDate: Fri, 24 Mar 2023 00:00:00 +030
A comprehensive survey of the urban building energy modeling (UBEM)
process and approaches
- Authors: Melik Ziya YAKUT; Sinem ESEN
  Abstract: Fossil fuels increase the emission values of greenhouse gases such as CO2 in the atmosphere and cause global warming and climate change. At the same time, fossil fuel reserves are facing depletion in the near future, and energy supply also has an important dimension such as national security and foreign dependency. All these show that turning to renewable energy sources and developing solutions and policies for energy saving has become a necessity both globally and locally. For such reasons, modeling of urban structures, which have a great contribution to energy consumption, and simulating the energy demand on an urban scale are of great importance for the effective use of energy. Research on this has shown that UBEM (Urban Building Energy Modeling) is an effective solution to these problems. However, UBEM contains different technical problems for implementation. Due to its versatility, various concepts related to this field lead to complexity. With this increasing complexity, there is a growing need to compile concepts from a holistic perspective. In this study, it is aimed to create a solution to these challenges. For this purpose, a comprehensive and up-to-date research of various modeling approaches and model creation process used in urban building energy modeling has been conducted. Studies on these approaches are summarized and a systematic review of the literature is made. At the same time, the study is in the nature of guiding and forming the general knowledge level with the basic concepts that should be known to those who will work on UBEM.
  PubDate: Fri, 24 Mar 2023 00:00:00 +030
Small hydropower development in Turkey: An overview of 2021
- Authors: Alaeddin BOBAT
  Abstract: Hydropower plants with an installed capacity of less than 10 MW are widely considered as small hydropower (SHP) in Turkey. There are currently 371 SHPs in operation as of 31 December 2021. Of these, 14 are operated by the DSI and 357 are operated by the private sector; and the installed capacity of the operating SHPs is 1.756,69 MW, their total generation potential is 6.643,44 GWh/year. Moreover, 12 SHPs are under construction. In addition, 625 SHP projects of 2.645,56 installed capacities and of 8.728,460 GWh/year generations potential were cancelled. Regionally, 34.50 % of SHPs (128 SHP) is located in the Black Sea Region of Turkey. 20.75 % of them (77 SHP) is located in the Mediterranean Region; 16.71 % (62 SHP) in the Eastern Anatolia Region; 12.94 % (48 SHP) in the Central Anatolia Region; 8.09 % (30 SHP) in the Marmara Region; 6.2% (23 SHP) in the Aegean Region and 0.08 % in the South-East Region. This article intends to discuss SHP’s in 2021 of Turkey as a whole and examine the place and importance of SHP’s in the sector.
  PubDate: Fri, 24 Mar 2023 00:00:00 +030
Ensuring energy balance for sudden demand changes in smart grids
- Authors: Ahmet KARYEYEN; Nurettin ÇETİNKAYA
  Abstract: With the increasing diversity in the use of electrical energy and the inclusion of renewable electricity power plants in the system, more efficient and more controllable electrical power systems are provided by smart grid technologies. Load balance based on pricing in electrical power systems; It is a strategy that takes into account customer demands, enables customers to use electrical energy at the most attractive price, and provides suppliers with the desired profit, that is, in summary, it coordinates the efficient operation of energy systems. In this study; While load balance is created with smart grid technology, demand-supply-price balance is achieved by using an optimum Fuzzy Logic PI controller within a closed-loop electric power control system model. Within the scope of the study, the simulation results obtained by applying 6 different demand scenarios to the power system model consisting of different types of generation resources were given graphically and analyzed. The different demand scenarios applied include difficult demand conditions such as possible sudden increase or decreases in demand in the electrical power system.
  PubDate: Fri, 24 Mar 2023 00:00:00 +030
Effect of material on efficiency in alternators used in wind energy
- Authors: Kadir YILMAZ; Taner DİNDAR
  Abstract: It is seen that the use of wind energy as a renewable energy source in the world has increased recently. In addition to this, power plants are established for the production of high power electricity and the energy produced is given to the grid. However, in a region far from the urban area, electrical energy can be produced at small power levels. Radial flux permanent magnet alternators are the most widely used to generate electrical energy at small powers. Therefore, in this study, the effect on the efficiency of the materials used in radial flux permanent magnet alternators was investigated. Time savings can be achieved by analyzing the alternators used for the energy to be produced. The analyzes taken from the program contribute to the studies and may cause small deviations in real applications. In our study, considering the B-H characteristics of ferromagnetic materials, the effects of variable stator, rotor and magnet materials on the output performance were examined and comparisons were made by choosing the configuration with the best efficiency as a result of the optimization made. According to the graphical results obtained, time and cost savings were achieved.
  PubDate: Fri, 24 Mar 2023 00:00:00 +030
Simulation of a PV module at different set-up and operating conditions to
give I-V and P-V curves
- Authors: Anas BALA; Jamilu Ya'u MUHAMMAD, Kadawa Ibrahim ALİ, Richard Balthia MSHELLİA
  Abstract: Solar energy is among the source of energy that is reliable, available and non-harmful to the society. The output of solar photovoltaic system can be improved by means of solar tracking system either mechanically or electrically. The low conversion efficiency of PV modules, which is significantly impacted by operational conditions, is the primary constraint of PV systems. The financial risk of installing a system for maximum power output is increased by improper assessment of PV module at various configurations and operating conditions and the performance of solar modules strongly depends on the temperature of the solar modules. This present work investigates the effect of temperature on PV module using Scilab XcosTM simulation software at different setups and operating conditions to give I-V and P-V curves in order to evaluate its output performance. The results of the simulations show that the voltage across the PV module at open circuit and current produced at short circuit increased with increasing the solar irradiance harnessed by the solar module from 700W/m2 to 1000W/m2 at constant temperature of 25 oC thereby increasing the maximum output power of the PV module. The results also revealed that using standard test condition (STC) parameters at different operating conditions of PV module the increment of short circuit current is more significant as open circuit voltage than current produced at short circuit.
  PubDate: Fri, 24 Mar 2023 00:00:00 +030