Browsing by Author "Cam, Nezir Yagiz"

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Citation - WoS: 36
Citation - Scopus: 42
Cooling channel effect on photovoltaic panel energy generation
(PERGAMON-ELSEVIER SCIENCE LTD, 2021) Zeynep Ozcan; Miray Gulgun; Ecem Sen; Nezir Yagiz Cam; Levent Bilir; Gulgun, Miray; Sen, Ecem; Ozcan, Zeynep; Bilir, Levent; Cam, Nezir Yagiz
It is a well-known fact that even though the electricity generation is higher when the solar radiation is high on a photovoltaic panel its efficiency drops as its temperature increases. In this study it is intended to achieve cooling effect using an air duct placed under a photovoltaic panel thereby increase its efficiency. Hourly electricity generation PV efficiency and cell temperature values over a year are calculated using annual temperature and radiation data by using MATLAB and PV Sol software. Maximum cell temperature for the uncooled case is determined as 57.91 degrees C on July 21st at 1p.m. as a result of hourly calculations. The incident solar radiation is 976 W/m(2) when the panel reached its maximum temperature. The PV panel and cooling channel are modelled in ANSYS Fluent software and cooling effect was investigated for different air velocities and air-cooling channel geometries for the hour when maximum cell temperature is reached. Environmental analyses are also made. It is observed that with finned cooling channel it is possible to cool PV temperature more than with the flat cooling channel. Cooling the PV panel from its maximum cell temperature to 39.82 degrees C with 5 m/s air velocity and 82 fins cooling channel is achieved and new PV panel efficiency is recorded as 18.92 %. Environmentally considerations show that the use of solar energy provides the reduction of coal and natural gas-based CO2 emissions as 15 and 8 tons respectively.
Citation - WoS: 5
Citation - Scopus: 4
Development of an integrated underfloor heating system model in TRNSYS and performance assessments
(Elsevier Ltd, 2024) Okan Gök; Nezir Yağız Çam; Ersin Alptekin; Mehmet Akif Ezan; Aytunç Erek; Gok, Okan; Alptekin, Ersin; Ezan, Mehmet Akif; Erek, Aytunc; Cam, Nezir Yagiz
In this study a transient model for a solar underfloor heating system with a sensible heat thermal energy storage (SHTES) system to meet the heating demand of a residential building is developed in TRNSYS software. As a novelty in the current model rather than using the built-in modules in the software an in-house MATLAB routine is implemented in TRNSYS to simulate the spatial and temporal variations inside a 2D slab-type SHTES tank. Long-term dynamic simulations are conducted to discuss the influences of the design and working parameters on the (i) energetic and exergetic performances (ii) solar fraction and (iii) CO2 emissions associated with the alternative underfloor heating systems. Parametric analyses are performed for climatically different locations such as Izmir (Csa: Hot-summer Mediterranean climate) and Erzurum (Dfb: Warm-summer humid continental climate). Variations in charging loop mass flow rates have minimal impact on the overall system performance in Izmir and Erzurum compared to other design and working parameters. The highest energy efficiencies of the solar-aided underfloor heating system for Izmir and Erzurum are achieved for a comfort temperature of 20 °C with 32.9 % and 24.6 % respectively. Regarding exergy efficiency the highest was determined as 4.04 % with a 23.5 °C comfort temperature in Izmir and 3.89 % with a comfort temperature of 20 °C in Erzurum. As a final result of the environmental assessments integrating solar SHTES especially with a natural gas-based auxiliary heater significantly reduces CO2 emissions by 99.6 % and 50.0 % in Izmir and Erzurum respectively. © 2024 Elsevier B.V. All rights reserved.
Citation - WoS: 1
Citation - Scopus: 2
Modeling of a Solar-Aided Heating and Cooling System with Thermal Energy Storage for a Sustainable Agricultural Greenhouse
(Pergamon-Elsevier Science Ltd, 2025) Ghiat, Ikhlas; Ezan, Mehmet Akif; Cam, Nezir Yagiz; Bicer, Yusuf
Greenhouses, a primary feature of sustainable agriculture, necessitate sophisticated climate management due to the intricacies of heat and mass transfer processes. Computational modeling tools are utilized to simulate the microclimate within greenhouses under different design scenarios, determine heating and cooling loads, and ascertain optimal control strategies. The current study develops a novel simulation model of a solar-assisted chiller and heat pump system with a thermal energy storage unit for heating, cooling, and ventilation of a climate-controlled agricultural greenhouse. A comprehensive study of the thermal impact of ventilation control and shade cloth, which are passive air conditioning methods used in greenhouses, is conducted using the inhouse code developed in MATLAB. The greenhouse air conditioning system's energy consumption is reduced from 160,447.9 to 80,540.3 kWh by implementing ventilation control and shade cloth. This also leads to a reduction in carbon emissions from 86,882.5 to 43,612.6 kg-CO2 by 49.8 %.
Citation - WoS: 14
Citation - Scopus: 15
Thermal behavior of a solar-assisted latent heat thermal energy storage unit on the heating season under variable weather conditions
(ELSEVIER, 2022) Nezir Yagiz Cam; Ersin Alptekin; Levent Bilir; Mehmet Akif Ezan; Alptekin, Ersin; Bilir, Levent; Ezan, Mehmet Akif; Cam, Nezir Yagiz
Due to the fossil-fuel-related climatic problems which got worse in recent decades the worldwide share of renewable energy has significantly increased. Even though solar energy is one of the most accessible renewables it has an intermittent nature throughout the day. Different energy storage techniques are implemented to resolve the intermittency problem and make solar-aided energy accessible when it is needed. Energy use in buildings has a huge share of total energy demand and heating/cooling demands are responsible for most energy consumption in buildings. In this study the performance of a solar-assisted latent heat thermal energy storage (LHTES) unit integrated with a heat pump is investigated during the heating season under variable weather conditions. Phase change materials (PCMs) with different melting temperatures (T-m) and latent heat of fusions (h(sf)) are studied and parametric simulations are conducted to examine the proposed systems' economic advantage and payback duration. Variable weather conditions are defined in simulations and seven consecutive day analyses are conducted to ensure that results are not dependent on the initial conditions. Results revealed that the PCM with T-m= 35 degrees C and h(sf) = 240 kJ/kg has a better thermal performance than the other alternatives i.e. T-m = 31 degrees C and 40 degrees C. The integration of the solar-aided LHTES unit with the heat pump increases the COP of the heat pump and the increment varies from 35% to 80% for heating months in Izmir. Such an improvement in COP reduces the operating costs related to the electricity consumption of the heating device significantly and the simple payback period of the combined system is determined to be approximately 13 years in Izmir.