Yazar "Dik, Abdullah" seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • [ X ]
    Öğe
    A comprehensive review of miscellaneous heat transfer enhancement designs of phase change material integrated heat exchanger
    (Elsevier Ltd, 2025) Erdinç, M. Tahir; Dalgıç, İrem; Kutlu, Cagri; Dik, Abdullah; Tokgoz, Nehir; Su, Yuehong; Riffat, Saffa
    This comprehensive review focuses on the specific investigation of heat transfer enhancement with a primary objective of achieving more uniform melting/solidification within heat exchangers employing phase change materials (PCM). The paper begins highlighting the crucial role of heat exchangers and introduces the unique studies associated with achieving uniform phase changes. The main body of the paper seeks to explore heat transfer enhancement strategies, particularly within shell-and-tube structures and plate heat exchanger (PHE). Moreover, the study discusses the role of these strategies in achieving more uniform melting/solidification in phase change materials. Special attention is applied to examining advancements and methodologies aimed at optimizing heat transfer for improved performance in applications requiring control of phase changes. As a new contribution, the paper examines the application of PCM in PHEs, providing insights into their effectiveness in facilitating more uniform phase change and PCM usage in these heat exchangers. Notable improvements were also observed from literature studies with specific fin geometries, where longitudinal and spider-web-like structures reduced solidification times by as much as 63 % and enhanced melting uniformity by 47.9 %. Operational parameter optimization, particularly through increasing heat transfer fluid (HTF) inlet temperature by 10 °C, resulted in a 35 % decrease in charging time, underscoring the importance of temperature control in Thermal energy storage (TES) applications. The literature studies mentioned that enhanced PHE configurations, including corrugated and zigzag plate designs, have demonstrated up to nine times faster charging and discharging rates compared to traditional concentric systems due to increased surface area. This study provides essential insights for researchers and practitioners aiming to enhance heat exchanger designs for critical applications in thermal energy storages. © 2025 Elsevier Ltd
  • [ X ]
    Öğe
    A study on the combination of crystallization-controllable phase change materials and solar-assisted heat pump for electricity demand shifting in space heating
    (Pergamon-Elsevier Science Ltd, 2025) Kutlu, Cagri; Erdinc, Mehmet Tahir; Dik, Abdullah; Chen, Ziwei; Lyu, Qinghua; Su, Yuehong; Riffat, Saffa
    Supercooled phase change materials offer a promising solution for space heating due to their ability to release latent heat upon crystallization initiation, even when stored at ambient temperatures. This unique property makes them ideal for solar-assisted space heating, where external activation enables on-demand heat release, addressing the critical need for energy-efficient heating solutions. In this study, a system promoting demand shifting is proposed, aiming to transfer energy consumption from morning and evening peak periods to daytime and high solar irradiance days, thereby enhancing the efficiency of solar heat pumps and reducing grid stress through the use of supercooled crystallization-controllable phase change materials. A model was developed, consisting of evacuated tube collectors, a buffer tank, heat storage tanks with crystallization-controllable phase change material, and a building heating demand model. The study introduces a novel system control methodology, focusing on an effective operation of tank shifting based on the heating requirement and solar energy availability. Real weather data were used to calculate system performance. With 50 m2 of collectors, a 1000-liter buffer tank, and a heat pump with a maximum output of 7 kW, the heat storage tanks are charged and discharged following the developed operational methodology. The system achieved a weekly coefficient of performance of 3.56 and successfully shifted electricity demand to solar hours, with only 28.5% of the total consumption occurring during domestic morning and evening peak times.
  • [ X ]
    Öğe
    Comparative Analysis of Solar Photovoltaic/Thermal Assisted Heat Pump Systems Coupled with PCM Storage and EV Charging with Reference to the UK's National Carbon Intensity
    (Mdpi, 2025) Kutlu, Cagri; Dik, Abdullah; Erdinc, Mehmet Tahir; Su, Yuehong; Riffat, Saffa
    Emerging trends in heat pump (HP) and electric vehicle (EV) adoption within communities aim to reduce carbon emissions in the heating and transportation sectors. However, these technologies rely on grid electricity, whose carbon intensity varies over time. This study explores how the carbon-saving potential of these technologies can be further enhanced through demand-shifting operations and renewable energy integration. The research compares photovoltaic-thermal (PV/T) and hybrid solar heat pump systems that integrate EV charging and PCM-enhanced heat storage to improve space heating efficiency under low solar irradiance in the UK while reducing CO2 emissions. The study simulates solar collector configurations and sizes, combining PV modules and heat pumps to enhance system performance. Control systems synchronize operations with periods of low grid CO2 intensity, minimizing the environmental impact. The analysis evaluates PV/T systems, separate PV and thermal collectors, highlighting their energy efficiency and CO2 reduction potential. Control systems further optimize HP operation and EV charging during periods of high renewable energy availability, preventing uncontrolled use that could result in elevated emissions. Using real weather data and a detailed building model, the findings show that a solar-assisted HP with 100% thermal collectors achieves a daily COP of 3.49. Reducing thermal collectors to 60% lowers the COP to 2.57, but PV output compensates, maintaining similar emission levels. The system achieves the lowest emission with high-efficiency evacuated flat plate PV/T collectors.