In this study, the effect of the fin surface on the electrical performance of passively cooled photovoltaics (PV) modules equipped with flat (${\mathrm{PV}}_{\mathrm{f}}$ ) and tread (${\mathrm{PV}}_{\mathrm{t}}$ ) surface finned heat sinks was experimentally investigated. ${\mathrm{PV}}_{\mathrm{f}}$ and ${\mathrm{PV}}_{\mathrm{t}}$ modules were fabricated with heat sinks by filling phase change material (paraffin)/aluminum chip mixture between the PV module and heat sink. The mean ambient temperature, solar radiation, and solar power during the experiment were about 13°C, $864\mathrm{W}/{\mathrm{m}}^2$ , and 247, respectively. The electrical power of the ${\mathrm{PV}}_{\mathrm{f}}$ and ${\mathrm{PV}}_{\mathrm{t}}$ modules was increased by 10.84% and 17.2%, respectively, while the average temperature was decreased by 11.78% and 16.5%, respectively, compared to the PV module. The ${\mathrm{PV}}_{\mathrm{t}}$ module provided 5.37% more effective cooling and a 5.74% higher electrical power than the ${\mathrm{PV}}_{\mathrm{f}}$ module. The electrical efficiency of the PV module was 11.35%, and the rate of increase was 1.21% and 1.95% for the ${\mathrm{PV}}_{\mathrm{f}}$ and ${\mathrm{PV}}_{\mathrm{t}}$ modules via cooling. Compared to the PV module, the electrical exergy of the ${\mathrm{PV}}_{\mathrm{f}}$ and ${\mathrm{PV}}_{\mathrm{t}}$ modules increased by 10.84% and 17.2%, respectively, at an average solar exergy of 230.61 W, while their thermal exergy decreased by 23.64% and 32.3%, respectively. Compared to the ${\mathrm{PV}}_{\mathrm{f}}$ module, the thermal exergy of the ${\mathrm{PV}}_{\mathrm{t}}$ module was reduced by 11.34%, and the electrical exergy was increased by 5.74%. The increase in exergy efficiency is 3.14% and 4.51% for ${\mathrm{PV}}_{\mathrm{f}}$ and ${\mathrm{PV}}_{\mathrm{t}}$ modules versus the PV module. A small part of solar energy is converted into electricity, while a significant part is converted into heat and increases the temperature of the PV cells. An increase in the temperature of PV cells harms conversion efficiency and causes an increase in the share of converted heat and a decrease in electricity generation. The conversion efficiency can be improved by removing the accumulated heat of the module. In practice, there are various examples of passive and active cooling. Active cooling methods enhance heat transfer by forcing the fluid flow with a fan or pump to facilitate heat removal. Active cooling applications are heavy, expensive, and complicated. Natural heat convection can be maximized with heat spreaders or heat sinks during passive cooling. Passive cooling may not dissipate heat as effectively as active cooling. Passive cooling systems are cheap, lightweight, and uncomplicated, and they can become even more valuable as their thermal efficiency increases. This study addresses the effect of the heat sink fin surface on the cooling and electrical performance of flat and tread finned heat sinks coupled PV modules that are paraffin/aluminum chips blend backplane filled. 1st and 2nd law PV module efficiencies improved by about 1.21% and 1.95% and 3.14% and 4.51% with flat and tread finned heat sinks, respectively.

Solar energy is a type of renewable energy that is readily available, but it must be converted to a usable form using a highly efficient method. The global energy problem that has surfaced in recent years shows the importance of both practical and scientific studies on using solar energy for space heating. Solar air heaters are large volume systems used for space heating. Research on the geometry and surface forms of solar air collectors is focused on reducing system volume and optimizing the use of solar energy. A photovoltaic (PV) module can be cooled with a fluid to prevent a decrease in efficiency due to heat while generating electrical power. The subject of this study is the idea of using the heat from cooling the modules to support a solar air heater. The improvement of the thermal performance of a solar air collector with a cooling thermal load of the concentrated photovoltaic thermal collector (CPV/T) was experimentally investigated. The heat exchanger, which removes the heat of the water-ethylene glycol circulating in the photovoltaic thermal collector, is mounted in the solar air heater’s chamber of one of the two identical solar air heaters, and the first hybrid unit was obtained (i.e., first unit). The ordinary one was called the second unit. Heated air left the first and second units at average temperatures of 45.87°C and 38.83°C, respectively. Although the airflow rates in the units are the same, the air temperature in the first unit was increased by 18.13%. The heat contribution of the heat exchanger to the first unit was 128.96 W. The first and second law efficiencies of the first and second units were calculated as 51.89%, 15.22%, and 45.4%, 10.34%, respectively. The energetic and exergetic improvement of the first unit was found to be 6.49% and 4.88%, respectively. The local solar utilization capability is $797.76\mathrm{kW}·\mathrm{h}/\mathrm{year}$ and $609.12\mathrm{kW}·\mathrm{h}/\mathrm{year}$ for the first and second units, respectively. The waste heat from the CPV/T collector cooling cycle, which is $188.64\mathrm{kW}·\mathrm{h}/\mathrm{year}$ , was recovered for heating air in the first unit. The recovery of waste heat for use in the first unit provided a significant performance improvement over the second unit. The environmental contribution of the waste heat recovery means 144 kg ${\mathrm{CO}}_2$ emission per year less in emission release. This study addresses the process of supporting the performance of a solar air heater with the waste heat obtained during the liquid cooling application of a CPV/T collector. The heat exchanger of a closed loop that cools a CPV/T collector was placed in the solar air heater’s chamber of the first solar air heater unit. The heat released from the heat exchanger increased the unit’s heating capacity. The improvement achieved with the first unit compared to the second unit is evaluated by comparing it to the second unit but without a heat exchanger attachment. While solar utilization in the first unit reached 525.19 W, the second unit provided 401 W of solar utilization. The energy and exergy values of the first and second units were found to be 51.89%, 15.22%, and 45.4%, 10.34%. When evaluating the use of solar energy instead of fossil fuel-based heating applications, it is predicted that the local gain can be $767.76\mathrm{kW}·\mathrm{h}/\mathrm{year}$ and $609.12\mathrm{kW}·\mathrm{h}/\mathrm{year}$ . In recent years, active cooling of PV modules is a popular method to prevent a decrease in module efficiency due to a rise in the PV module temperature. Gaining use of the thermal load removed from the PV module is another well-known subject. In this study, $188.64\mathrm{kW}·\mathrm{h}/\mathrm{year}$ of thermal load from the CPV/T collector was recovered to the heating air in the first unit. In this way, the efficiency of the first and second laws of the first unit increased by 6.49% and 4.88%, respectively, compared to the second unit. The idea of the hybrid solar air heater contributes to researchers working in this field and raises awareness among practitioners.

Şırnak ve çevresinde önemli miktarlarda bulunan asfaltitlerin, fiziksel ve kimyasal özellikleri kömüre yakındır. Fakat oluşum kaynakları ve kimyasal süreçler nedeniyle kömürden farklıdır. Asfaltitler, tektonizmayla sıvı haldeki petrolün kendi konumundan ayrılarak başka konumlara yerleşip, jeolojik süreçler boyunca kimyasal reaksiyonlarla sertleşip, katı faza dönüşmüştür. Güneydoğu Anadolu Bölgesi’nde ısınma ihtiyacının çoğu asfaltitlerden karşılanmaktadır. Ancak, düşük ısıl değeri, yüksek oranlarda kül, kükürt ve nem içeriği sahip olmalarıyla kalorisi düşük ve hava kirliliğine olumsuz etki etme potansiyeli yüksek hammaddedir. Yapısında azot ve sulu ortamda yavaş çözünen hümik asit bulunmakta ve toprak güçlendirici olarak kullanılabilir. Bu çalışmada, Uludere ilçesinde bulunan maden rezervinden alınan asfaltit numunelerinin içeriğinden doğal hümik asitin elde edilmesine yönelik araştırmalar yapılmıştır. Numuneler ile yapılan deneylerde optimal humik asit kazanma verimine yönelik, pH değişimleri sıcaklık değişimleri, karıştırma sürelerinin değişimleri, KOH ve HCI çözeltisindeki çöktürmenin etkileri incelenmştir. Buna göre Uludere bölgesi numunesinden sıcaklık deneyleri ile yapılan çalışmalar sonucunda en yüksek % 33,95 verimle doğal hümik asit elde edilmiştir.

Endüstriyel ve tarımsal ürünler, doğal ve teknik yöntemler kullanılarak kurutulabilir. Kurutma maliyetini sıcak kurutma havasını elde etmek için harcanan enerji oluşturur. Bu çalışmada, kurutmanın enerji problemine çözüm üretmeye yönelik ısı borulu düzlemsel güneş kollektörlü ve ısı geri kazanımlı bir kurutma sistemi tasarlanmıştır. Karabük ili iklim şartlarında, sabit 1 m/s kurutma hızında, farklı ışınım değerlerinde, kuruma havası sıcaklığının değişimleri, ürün kütle kaybı ve kalitesi, ısı geri kazanımının sisteme katkısı deneysel olarak incelenmiş ve teorik analizleri yapılmıştır. Sistemde kapalı çevrimde içerisine ürün konulmadan yapılan deneyde sabit hava hızında ve ortalama 770 W/m2 ışınım değerinde kurutucu sıcaklığının dış hava sıcaklık değerinin yaklaşık olarak %49’luk bir artışla ortalama 14,63 °C üzerine çıktığı belirlenmiştir. Ürün ile kurutma deneyinde kivi meyvesi kullanılmıştır. Etüv fırınında kurutulan kivilerde yaş baza göre hesaplanan nem miktarı 0.83 g su/g yaş madde, kuru baza göre hesaplanan nem miktarı 4.94 g su/g kuru madde ve kuru madde miktarı %16,8 olarak belirlenmiştir. Kurutma işlemine, son üç ağırlık değerleri eşit çıkana kadar devam edilmiş ve nem değeri 0,03 g su/g kuru madde olana kadar kurutma gerçekleştirilmiştir. Ölçümler sonucunda ortalama 39.4 g değerine kadar kurumanın gerçekleştiği ve ürün ağırlığının %80 azaldığı belirlenmiştir. Sistemin genel verimi 4 Eylül saat 15:50’de 694,3 W/m2 ışınım değerinde maksimum %39, ısı borulu kollektörün ortalama verimi %24 ısı geri kazanım ünitesinin verimi %28’dir. Kurutma işleminde harcanan enerjinin %27’si ısı geri kazanım ünitesi, %73’ü de ısı borulu kollektör tarafından karşılanmıştır.

Nanoakışkanlar, farklı tipteki ısı borularının ısı transfer performansını etkili bir şekilde artırabilir. Farklı nanopartiküller, konsantrasyonlar, paketleme oranları, eğim açıları ve ısıl yükler gibi önemli değişkenlerin ısı borusu performansı üzerindeki etkisi bu çalışmada anlatılmıştır. Çalışmalar, daha verimli kullanım için belirli bir nanopartikül konsantrasyonu olduğunu belirtmektedir. Yüksek nanopartikül konsantrasyonu, esas olarak dinamik viskozitedeki artış ve partikül topaklanma olasılığı nedeniyle daha yüksek ısıl dirence yol açmaktadır. Nanoakışkan kullanımı ile ısı borularının ısı transfer performansındaki artışın, gelişmiş Brownian hareketi, geliştirilmiş yüzey ıslanabilirliği, artan çekirdeklenme bölgeleri ve nanoakışkanların yüksek ısıl iletkenliğinden kaynaklanmaktadır.

In this study, it was experimentally investigated that the groundwater of a well is brought to the surface using solar energy, which is one of the renewable energy sources, and the cooling of a place with this water with low energy density. The study evaluated cooling performance on two different days (Exp. 1 and Exp. 2) and at two different cooling water flow rates. The efficiency of the PV system was found to be 8.33±0.44% in Exp. 1 and 8.3±0.44% in Exp. 2. The cooling loads of the cooled buildings differ in Exp. 1 and Exp. 2 due to ambient conditions. The cooling load in Exp. 1 was determined to be 572±22.8 W and in Exp. 2 about 828±33.1 W. The heat loads extracted from the building by the groundwater used as a cooling fluid are 410±16.4 W and 786±31.4 W for Exp. 1 and Exp. 2. The cooling performance evaluation criteria (CPEP) value was found to be 0.72 for Exp. 1 and 0.95 for Exp. 2. Although there was a significant difference between the cooling loads for Exp. 1 and Exp. 2, the cooling load coverage increased with the increase in cooling water flow rate according to the CPEP values. Although in both experiments the cooling load was not fully met and the temperature inside the structure rose slightly during the experiment, it was kept cool.