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Öğe Development, characterization and thermo-regulative performance of microencapsulated phase change material included-glass fiber reinforced foam concrete as novel thermal energy effective-building material(Pergamon-Elsevier Science Ltd, 2022) Gencel, Osman; Subaşı, Serkan; Ustaoğlu, Abid; Sarı, Ahmet; Maraşlı, Muhammed; Hekimoğlu, Gökhan; Kam, ErolThermal energy storage (TES) materials present very crucial role for heating and cooling load of building envelopes. This investigation focused on manufacturing of novel TES materials as a lightweight concrete by integration of microencapsulated PCM (MPCM) with foam concrete (FC) to improve thermal mass of buildings. Novel hybrid building material design is presented by combining static insulation property of FC and dynamic thermoregulation property of MPCM. In production of MPCM-included innovative FC, MPCM was used at 5%, 10% and 15% by weight. MPCM increased bulk density up to 592.1 kg/m(3), compressive strength up to 2.52 MPa and thermal conductivity up to 0.153 W/mK. Fourier transform infrared spectroscopy (FTIR) analysis confirmed that any chemical interaction did not occur between MPCM and ingredients of FC. Onset melting temperature and energy storage capacity were measured as 11.88 degrees C and 204 J/g for MPCM and 12.27 degrees C and 30.8 J/g for FC-MPCM, respectively. Center temperature of room with MPCM impregnated foamed concrete became about 1.9 degrees C lesser according to reference room through daytime. Moreover, it achieved about 1.72 degrees C higher room center temperature after sunset hour. Advantageous physico-mechanic and thermal properties make FC-MPCM as promising energy effective material for manufacturing thermo-regulative building components. (c) 2022 Elsevier Ltd. All rights reserved.Öğe Effect of carbon nanotube and microencapsulated phase change material utilization on the thermal energy storage performance in UV cured (photoinitiated) unsaturated polyester composites(Elsevier, 2023) Subaşı, Azime; Subaşı, Serkan; Bayram, Muhammed; Sarı, Ahmet; Hekimoğlu, Gökhan; Ustaoğlu, Abid; Gencel, OsmanThe utilization of phase change materials in the synthesis of polyester is an economically viable approach for the production of polymer composites with remarkable thermal and mechanical characteristics, thereby facilitating thermal energy savings. This study manufactured a series of unsaturated polyester resin (UPR)/carbon nanotubes (CNT)/MPCM composites via mechanical mixing and ultrasonication processes and the produced composites were cured with ultraviolet (UV) curing technology. The unsaturated polyester resin was utilized as a support matrix, and to improve the thermal conductivity of MPCM-UPR composites, CNT were introduced into the matrix. This paper discusses the effect of CNT and MPCM on the mechanical, thermal, and thermal regulative performance of polyester composites. A 10 wt% incorporation of MPCM led to an almost 77 % and 15 % drop at Charpy impact strength and Shore D hardness values of reference UPR, respectively. Similarly, the introduction of substitution of 0.005 wt% of CNT reduced the impact strength of the specimen with 10 % MPCM by 31 %, while it increased the Shore D hardness by almost 5 %. Although the thermal conductivity of reference resin was reduced by 15 % with a 10 % addition of MPCM, CNT content increased the thermal conductivity values by almost 20 % regardless of MPCM concentration. The onset melting and freezing temperatures of MPCM were found to be 21.71 and 22.74 degrees C, respectively; while for the composites with and without CNT, this value ranged between 20.70 and 22.39 degrees C and 22.45-22.90 degrees C, respectively. Thermoregulation test results indicate that MPCM improved the thermal energy storage capacity of composites. The results of this research will be of great sig-nificance in order to gain a more comprehensive understanding of the thermal properties of polyesters with MPCM/CNT, thus allowing for the utilization of this material as a latent heat thermal energy storage system for energy conservation.Öğe Glass fiber reinforced gypsum composites with microencapsulated PCM as novel building thermal energy storage material(Elsevier Sci Ltd, 2022) Gencel, Osman; Hekimoğlu, Gökhan; Sarı, Ahmet; Ustaoğlu, Abid; Subaşı, Serkan; Maraşlı, Muhammed; Erdoğmuş, ErtuğrulA comprehensive study involving the fabrication and characterization of gypsum plasterboards combined with microencapsulated phase change material (mPCM) is introduced to evaluate their benefits regarding thermoregulation management and energy saving performance in buildings. For this purpose, the produced new type of gypsum plasterboard was subjected to the detailed chemical, morphological, mechanical, physical and thermal tests. The gypsum plasterboard incorporated with mPCM (7.5 wt%) and reinforced by glass fiber has latent heat capacities as high as 16.7 and 16.6 J/g at onset melting and solidification temperature of 11.90 ? and 12.09 ?, respectively. TGA analyzes revealed high thermal stability of gypsum plasterboard up to about 140 ?. Outcomes exhibited that mPCM-gypsum plasterboard can substantially diminish cooling load of a building during the daytime even at the high room temperature and offer decline in heat necessity of a house during night-time. During peak room temperature hours, the mPCM-gypsum plasterboard achieved 3 ? lower temperatures than the reference room, and it provided a cooler room temperature for about 7 h during the daytime while a warmer temperature of 0.3 ? was achieved at the cold weather. As a result, the produced gypsum-based composites can be considered as an energy-saving and indoor temperature regulating material in buildings.Öğe Jeotermal Enerji Kaynaklı Ara Isıtmalı Organik Rankine Çevriminin Konvansiyonel ve İleri Ekserji Analizi(2020) Ustaoğlu, AbidEkserji analiz metodu üretilen faydalı işin belirlenmesinde önemli bir araçtır. Ancak sadece ekserji analizi ileçevrimde kullanılan komponentler arasındaki etkileşimin, yani komponentte oluşan ekserji yıkımınınkomponentin kendisinden mi yoksa etkileşimde bulunduğu diğer komponentlerden mi kaynaklandığını veyasistemin gerçek geliştirilme potansiyelini, yani sistemde ve komponentlerde oluşan ekserji yıkımlarından nekadarının önlenebileceğini belirlemek mümkün değildir. Bu yüzden ileri ekserji analiz metodu kullanılmaktadır.Bu çalışmada, iş akışkanı olarak R152a kullanan jeotermal destekli ara ısıtmalı organik Rankine çevriminingerçek geliştirilme potansiyelinin ve çevrimde bulunan komponentler arasındaki etkileşimin belirlenmesi içinkonvansiyonel ve ileri ekserji analizleri yapılmıştır. Sistemin geliştirme potansiyelini belirlemek için ekserjiyıkımının önlenebilir/kaçınılamaz kısımları belirlenmiştir. Komponentler arasındaki etkileşimin detaylıcabelirlenmesi için de içsel/dışsal ekserji yıkımları belirlenmiştir. Ayrıca yoğuşturucu ve buharlaştırıcıbasınçlarının sistem performansı üzerindeki etkisi incelenmiştir. Ekserji ve enerji verimleri sırasıyla %50.69 ve%14.04 olarak hesaplanmıştır. İleri analiz sonuçlarına göre sistem çok büyük oranda kaçınılmaz (%95.04) veiçsel (%86.6) ekserji yıkımlarına sahiptir. Buradan sistemin sadece %5’lik bir geliştirme potansiyeli olduğugörülmektedir. Türbinlerdeki tersinmezliklerin tamamı dışsal iken, pompa ve buharlaştırıcıdaki tersinmezliklerbu komponentlerin kendilerinden kaynaklanmaktadır. Toplam içsel ekserji yıkımının en yüksek yüzdesi yaklaşık%93 ile buharlaştırıcıda meydana gelmiştir. En yüksek ekserji yıkımı buharlaştırıcıda olmakla birlikte bubileşendeki geliştirme potansiyeli sıfırdır. Türbinlerdeki önlenebilir ekserji yıkımı, toplam önlenebilir kısmın%85.34’üne eşittir. Sonuçlar, sistemin performansını geliştirmek için öncelikle odaklanılması gerekenkomponetlerin alçak ve yüksek basınç türbinleri olduğu göstermektedir.