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Abstrak :
ABSTRAK
Efisiensi suatu kolektor Surya konvensional (tube solar collector) dapat ditingkatkan dengan melapisi dinding dalam tabung-tabung kolelctor dengan Suatu media berpori. Dalam penelitian ini, metode di atas akan disimulasikan dengan menggunakan Compufatiozzai Fluid Dynamics (CFD). Simulasi akan dilakukan terhadap salah satu tabung dari suatu tube solar collector yang dilapisi dengan media berpori dengan ketebalan tertentu, yaitu dimulai dengan tabung tampa penambahan media berpori (N1= 1) hingga tabung yang dipenuhi dengan media berpori. (N1= O). Dari simulasi ini dapat diperoleh data-data mengenai temperatur outlet, sehingga modifikasi tersebut dapat dilihat pengaruhnya terhadap efisiensi kolekton Dari hasil simulasi didapatkan bahwa dengan penambahan media berpori maka etisiensi dapat ditingkatkan khususnya pada kolektor dengan koefisien kerugian UL yang tinggi

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Abstrak :
Salah satu pemanfaatan energi terbarukan adalah energi matahari yang dimanfaatkan untuk Solar Thermal Cooling System dengan menggunakan Evacuated Tube Solar Collector (ETSC) untuk mengkonversi energi matahari menjadi energi kalor yang dapat memanaskan fluida kerja air tanpa menggunakan heater. Peneilitian ini bertujuan untuk mengetahui durasi pemanasan fluida kerja air dari suhu ambien hingga 50°C agar dapat dimanfaatkan untuk kebutuhan mandi air hangat sebanyak 50-liter dan 100-liter air. Penelitian ini menggunakan Standar ASHRAE 93-2003 yang menyediakan berbagai metode untuk menentukan performa dari solar kolektor, standard ini menggunakan single phase fluids dengan sistem close loop. Metode pengambilan data dilakukan dengan cara mempersiapkan measurement device sebagai mikrokontroller untuk menjalankan sensor thermocouple yang dimana sensor tersebut digunakan untuk mengambil data temperatur inlet dan outlet solar collector manifold, serta data radiasi didapatkan dari Pyranometer. Pengambilan data durasi pemanasan air sebanyak 50-liter dan 100-liter dilakukan dengan memvariasikan flow rate fluida kerja air yang bersirklus pada sistem, sebesar 2,6 LPM, 3,6 LPM, dan 4,6 LPM serta sudut kemiringan ETSC sebesar 15° yang berlokasi di Depok, Jawa Barat dengan kondisi cuaca aktual pada bulan November-Desember 2022. ......One of the uses of renewable energy is solar energy which is utilized for the Solar Thermal Cooling System using an Evacuated Tube Solar Collector (ETSC) to convert solar energy into heat energy which can heat the water working fluid without using a heater. This research aims to determine the duration of the heating of the water working fluid from ambient temperature to 50°C so that it can be utilized for the needs of 50-liter and 100-liters of water warm baths. This study uses the ASHRAE 93-2003 standard which provides various methods for determining the performance of solar collectors, this standard uses single phase fluids with a close loop system. The data collection method is carried out by preparing a measurement device as a microcontroller to run the thermocouple sensor where the sensor is used to retrieve the inlet and outlet temperature data of the solar collector manifold, as well as radiation data obtained from the Pyranometer. Data collection for the duration of water heating of 50-liters and 100-liters was carried out by varying the flow rate of the circulating water working fluid in the system, by 2.6 LPM; 3.6 LPM; and 4.6 LPM and an ETSC angle of 15° which is located in Depok, West Java with actual weather conditions in November-December 2022.

Abstrak :
Penelitian mengenai unjuk kerja solar termal kolektor terus mengalami kemajuan. Telah banyak inovasi dan temuan baru pada berbagai jenis kolektor non concentrating yang menyatakan peningkatan yang cukup signifikan dalam unjuk kerja solar termal kolektor.Olehkarena itu dibutuhkan suatu sistem sebagai fasilitas pengujian unjuk kerja, yang memiliki standar tertentu yang umum. Penelitian ini membahas sistem pengujian dengan standar ASHRAE-93 , yaitu meliputi perancangan fasilitas pendukung seperti frame, perhitungan instrumen-instrumen utama , dan pemilihan alat ukur yang sesuai dengan standar. Selanjutnya juga diberikan pembahasan mengenai proses assembling dan validasi alat-alat ukur. Dilakukan pengujian dengan menggunakan kolektor jenis Evacuated Tube Sollar Collector, yang dipasang di atas gedung MRC FTUI. Pengujian dimulai pukul 09.00 WIB hingga 15.00 WIB dibawah sinar matahari. Data yang diproleh yaitu temperatur inlet kolektor, temperatur outlet, temperatur ambien dan radiasi matahari setiap sepuluh menit. Diperoleh bahwa efisiensi pada pengujian ini adalah sebesar 50,7 % dengan persamaan garis karakteristik efisiensi y = -3.1836x + 0.057. ......Research on the solar thermal collector performance continues to progress. There have been many innovations and new findings on various types of non-concentrating collectors which state a significant increase in the performance of solar thermal collectors. Therefore, a system is needed as a performance testing facility, which has certain common standards. This study discusses the testing system with the ASHRAE-93 standard, which includes the design of supporting facilities such as frames, calculation of main instruments, and selection of measuring instruments according to standards. Furthermore, it is also given a discussion about the assembling process and validation of measuring instruments. The test was carried out using the Evacuated Tube Sollar Collector , which is installed on the rooftop of the MRC FTUI building. The experiment was carried out at 09.00 WIB to 15.00 WIB under the sun . The data obtained are collector inlet temperature, collector outlet temperature, ambient temperature and solar radiation every ten minutes. It was found that the efficiency of Evacuated Tube Sollar Collector was 50.7% with the efficiency characteristic line equation y = -3.1836x + 0.057.

Abstrak :
Performa dari kolektor surya (sollar collector) tergantung pada jumlah kolektor surya dan konfigurasi rangkaiannya. Ketika area yang digunakan besar atau luas maka semakin banyak kolektor surya yang diperlukan. Konfigurasi rangkaian seri-paralel digunakan untuk mendapatkan temperatur air panas yang diinginkan. Selain itu ada faktor eksternal yang harus diperhatikan, yaitu temperatur lingkungan, ketersediaan sinar matahari (solar radiation), dan laju aliran fluida (mass flow rate). Temperatur lingkungan dan sinar matahari merupakan faktor yang tidak dapat diatur karena tergantung pada cuaca. Sedangan laju aliran fluida merupakan faktor eksternal yang dapat kita sesuaikan dengan kebutuhan. Penelitian ini menggunakan software MATLAB untuk melakukan simulasi. Rangkaian kolektor pada penelitian ini merupakan rangkaian baru dari penelitian sebelumnya. Nilai laju aliran fluida dibuat bervariasi kemudian diuji dengan radiasi matahari yang berbeda-beda. Variasi laju aliran yaitu 1,6 kg/s, 2,38 kg/s, 3,16 kg/s, 3,94 kg/s, dan 4,72 kg/s. Berdasarkan simulasi yang telah dilakukan, perubahan laju aliran dapat berpengaruh pada performa rangkaian kolektor. Variasi pertama 1,6 kg/s mampu menghasilkan outlet temperature 75,2-87,5 C dengan effisiensi maksimum 66,84 %. Sedangkan variasi kedua 2,38 kg/s mampu menghasilkan outlet temperature 71,0-80,3 C dengan effisiensi maksimum 67,74 %. Variasi ketiga 3,16 kg/s mampu menghasukan outlet temperature 70,1-76,5 C dengan effisiensi maksimum 68,2 %. Lalu variasi keempat 3,94 kg/s mampu menghasilkan outlet temperature 69,1-74,3 C dengan effisiensi maksimum 68,47 %. Variasi kelima 4,72 kg/s mampu menghasilkan outlet temperature 68,4-72,7 C dengan effisiensi maksimum 68,65 %. Pada akhirnya penentuan nilai laju aliran yang tepat dapat diatur sesuai dengan kebutuhan di lapangan. Dalam rangkaian baru ini, jika ingin mendapatkan effisiensi yang relatif sama dengan rangkaian lama, namun dengan outlet temperature yang lebih tinggi maka dapat memilih untuk menggunakan laju aliran 4,72 kg/s.

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The solar collector's performance depends on the number of solar collectors and the configuration of the circuit. When the area used is large, more solar collectors are needed. The parallel-series configuration used to obtain the desired hot water temperature. Besides, there are external factors considered, namely the environment's temperature, solar radiation, and distribution of flow rates. Ambient temperature and solar radiation are factors that cannot be regulated because they depend on the weather. The flow rate is an external factor that we can adjust. This research uses MATLAB software to conduct simulations. The collector circuit in this study is a new series from previous studies. Variations of fluid flow rates are tested with different solar radiation. The flow rate variations are 1,6 kg/s, 2,38 kg/s, 3,16 kg/s, 3,94 kg/s, and 4,72 kg/s. Based on the simulation, changes in fluid flow rate (mass flow rate) can affect the performance of the collector circuit. The first variation of 1,6 kg/s can produce outlet temperature of 75,2-87,5 C with maximum effisiency of 66,84 %. While the second variation, 2,38 kg/s, can produce outlet temperature of 71,9-80,3 C with maximum efficiency of 67,74 %. The third variation can produce outlet temperature of 70,1-76,5 C. The fourth variation of 3,94 kg/s can produce outlet temperature 69,1-74,3 C with 68,47 % efficiency. The fifth variation of 4,72 kg/s can produce outlet temperature of 68,4-72,7 C with maximum efficiency of 68,65 %. In the end, determining the right mass flow rate can be adjusted according to the needs. In this new circuit, if we want to get the same value of efficiency as the old circuit, with a higher outlet temperature, we can use a mass flow rate of 4,72 kg/s.

Abstrak :
Energi terbarukan merupakan sumber energi alternatif yang tersedia melimpah di alam dan tidak akan pernah habis walaupun terus menerus digunakan. Pemanfaatan energi terbarukan juga diakibatkan karena efek yang ditimbulkan oleh emisi pembakaran energi fosil, membuat peneliti berfikir untuk mencari sumber energi alternatif yang lebih bersih dan aman bagi lingkungan. Salah satu pemanfaatan energi terbarukan adalah energi matahari yang dimanfaatkan untuk Solar Thermal Cooling System dengan menggunakan Evacuated Tube Solar Collector (ETSC) untuk mengkonversi energi matahari menjadi energi kalor yang dapat memanaskan heat transfer fluid  tanpa menggunakan heater. Solar Collector adalah salah satu instrumen yang penting dalam Solar Thermal Cooling System dan sistem pemanas air. Penggantian heat transfer fluid dari air ke nanofluida dapat meningkatkan perpindahan panas. Peneilitian ini bertujuan untuk mengetahui performa Evacuated Tube Solar Collector dengan penggunaan nanofluida berbahan dasar nanopartikel berupa Multi Walled Carbon Nanotube (MWCNT) dalam pemanasan air yang berfungsi sebagai Heat Transfer Fluid. Peneliatian ini menggunakan standar pengujian yang memiliki banyak metode untuk menentukan performa dari sebuah solar collector yaitu Standar ASHRAE 93-2003, standard ini menggunakan single phase fluids dan memakai sistem close loop. Metode pengambilan data dilakukan dengan mempersiapkan measurement device yang berfungsi sebagai mikrokontroller untuk merekam data yang diperoleh dari tiga buah sensor thermocouple dimana sensor tersebut diletakkan pada inlet dan outlet solar collector manifold, serta diletakkan di dalam storage tank untuk mengukur air yang akan dipanaskan, selain itu data radiasi yang didapatkan pada percobaan ini didapatkan dari pyranometer. Pengambilan data dilakukan selama 6 jam denganflowrate sebesar 2.6 LPM dan sudut kemiringan Evacuated Tube Solar Collector sebesar 15°. Penelitian ini berlokasi di Depok, Jawa Barat dengan kondisi cuaca aktual pada bulan Juni-Juli 2023 ......Renewable energy is an abundant alternative energy source in nature that will never be depleted even with continuous use. The utilization of renewable energy is driven by the effects caused by the emissions of fossil fuel combustion, prompting researchers to seek cleaner and environmentally safe alternative energy sources. One of the applications of renewable energy is solar energy, which is harnessed for Solar Thermal Cooling Systems using Evacuated Tube Solar Collectors (ETSC) to convert solar energy into heat energy capable of heating the heat transfer fluid without the use of a heater. Solar collectors are crucial instruments in Solar Thermal Cooling Systems and water heating systems. The replacement of the heat transfer fluid from water to nanofluids can enhance heat transfer. This research aims to determine the performance of the Evacuated Tube Solar Collector using nanofluids based on Multi Walled Carbon Nanotubes (MWCNT) as the Heat Transfer Fluid in water heating. The research adopts testing standards that encompass various methods to determine the performance of a solar collector, namely the ASHRAE 93-2003 standard, which employs single-phase fluids and a closed-loop system. Data collection is conducted by preparing a measurement device functioning as a microcontroller to record data obtained from three thermocouple sensors placed at the inlet and outlet of the solar collector manifold, as well as inside the storage tank to measure the water to be heated. Additionally, radiation data obtained in this experiment is acquired from a pyranometer. The data collection is performed for a duration of 6 hours with a flow rate of 2.6 LPM and an inclination angle of the Evacuated Tube Solar Collector set at 15°. This research is conducted in Depok, West Java, under the actual weather conditions of June-July 2023.

Abstrak :
Energi terbarukan telah menjadi topik penting dalam beberapa tahun terakhir karena meningkatnya kekhawatiran tentang perubahan iklim dan keterbatasan energi fosil. Salah satu sumber energi terbarukan yang menjanjikan adalah energi matahari, yang dapat dimanfaatkan tanpa menghasilkan emisi zat sisa dan tersedia di seluruh tempat. Salah satu aplikasi pemanfaatan energi matahari adalah Solar Thermal Cooling System (STCS), yang menggantikan sistem pendingin konvensional yang menggunakan refrigeran sintetis dan berkontribusi terhadap emisi gas rumah kaca. Evacuated Tube Solar Collector (ETSC) adalah salah satu jenis kolektor surya yang digunakan untuk memanaskan air dan memiliki efisiensi lebih tinggi dibandingkan kolektor surya datar karena menggunakan tabung vakum yang mengurangi kehilangan panas. Pada penelitian ini, performa ETSC diuji dengan menggunakan reflector di bagian bawah tabung yang divariasikan jenisnya, yaitu pelat galvalum dan pelat aluminium, dengan standar ASHRAE 93-2003 sebagai referensi. Pengujian dilakukan pada sudut kolektor surya 15° dengan flowrate sebesar 2,6 LPM. Hasil penelitian menunjukkan bahwa ETSC dengan reflector aluminium memiliki efisiensi rata-rata tertinggi (63%), diikuti oleh ETSC dengan reflector galvalum (55%), dan ETSC tanpa reflector (50%). Penggunaan reflector aluminium meningkatkan efisiensi sebesar 13%, sementara reflector galvalum meningkatkan efisiensi sebesar 5%. Oleh karena itu, penggunaan reflector aluminium lebih efektif dalam meningkatkan efisiensi ETSC dibandingkan dengan reflector galvalum. Hasil penelitian efisiensi ETSC tanpa reflector ini memiliki nilai lebih rendah daripada nilai efisiensi dari standar pengujian perusahaann yang sebesar 75%. Hal ini dapat disebabkan oleh beberapa faktor seperti perbedaan kondisi pengujian, kualitas peralatan, dan desain dan instalasi. ......Renewable energy has become a significant topic in recent years due to growing concerns about climate change and the limitations of fossil energy. One promising source of renewable energy is solar energy, which can be harnessed without producing emissions and is available everywhere. One application of solar energy utilization is the Solar Thermal Cooling System (STCS), which replaces conventional cooling systems that use synthetic refrigerants and contribute to greenhouse gas emissions. The Evacuated Tube Solar Collector (ETSC) is a type of solar collector used to heat water and has higher efficiency compared to flat plate solar collectors because it uses vacuum tubes that reduce heat loss. In this study, the performance of ETSC was tested using reflectors at the bottom of the tubes with different types, namely galvalume plates and aluminum plates, with ASHRAE 93-2003 standards as a reference. The tests were conducted at a solar collector angle of 15° with a flow rate of 2,6 LPM. The results showed that ETSC with an aluminum reflector had the highest average efficiency (63%), followed by ETSC with a galvalume reflector (55%), and ETSC without a reflector (50%). The use of an aluminum reflector increased efficiency by 13%, while the galvalume reflector increased efficiency by 5%. Therefore, the use of an aluminum reflector is more effective in improving ETSC efficiency compared to the galvalume reflector. The efficiency results of ETSC without a reflector are lower than the company's standard test efficiency value of 75%. This can be caused by several factors such as differences in test conditions, equipment quality, and design and installation.

Abstrak :
To solve current environmental problems such as global warming and declination of fossil fuels, use of less energy is essential, particularly in the fields of refrigeration and air conditioning. Thus, simulations using complex mathematical models become vital. Simulation technology faces a major challenge because the language of simulation codes varies depending on the programmer. Thereafter, others cannot duplicate the same simulation technology used by their predecessors. To address this, a modular analysis method that generalizes simulation code has been developed. With this method, the general-purpose software analyzing energy system called “ENERGY FLOW +M,” a software enabling analyses that can be conducted without having to specify the model or the method of analysis used, has also been created. The focus of this study was on the solar collector. As the solar collector uses energy from the sun, it is friendly to the global environment. In order to understand the performance of the solar collector, the construction of a simulation model was carried out. Moreover, models of the solar collector and solar radiation were loaded into “ENERGY FLOW +M” to verify their performance. Thus, this simulator allows us to execute simulations of the solar collector from anywhere via the Internet.

Abstrak :
To solve current environmental problems such as global warming and declination of fossil fuels, use of less energy is essential, particularly in the fields of refrigeration and air conditioning. Thus, simulations using complex mathematical models become vital. Simulation technology faces a major challenge because the language of simulation codes varies depending on the programmer. Thereafter, others cannot duplicate the same simulation technology used by their predecessors. To address this, a modular analysis method that generalizes simulation code has been developed. With this method, the general-purpose software analyzing energy system called “ENERGY FLOW +M,” a software enabling analyses that can be conducted without having to specify the model or the method of analysis used, has also been created. The focus of this study was on the solar collector. As the solar collector uses energy from the sun, it is friendly to the global environment. In order to understand the performance of the solar collector, the construction of a simulation model was carried out. Moreover, models of the solar collector and solar radiation were loaded into “ENERGY FLOW +M” to verify their performance. Thus, this simulator allows us to execute simulations of the solar collector from anywhere via the Internet.

Abstrak :
Indonesia’s economic growth has continued at a steady rate of approximately 5% to 6% annually, and energy consumption in the entire country has been increasing year by year. Demand for air conditioning in buildings is expanding. In line with this expansion, a 239 kW solar air-conditioning system using a single-double effect combined absorption chiller was installed in a building at the University of Indonesia’s Faculty of Engineering located in Depok city, near Jakarta, with the aim of reducing greenhouse gas emissions. We collected and analyzed data from this air-conditioning system to better comprehend its performance. We report the outline and the performance of the chiller and the air-conditioning system.

Abstrak :
Many studies show that nanofluids, especially with carbon nanotubes, improve heat transfer. Other studies show that a nanofluid is a good candidate for solar systems because of its good absorptivity. We are facing an increasing number of miniaturized and more powerful systems. Especially in microelectronics, small heat sinks with high heat transfer are being developed, called micro-channel heat sinks (MCHS). In this paper, the heat transfer behavior of carbon nanotube–water nanofluid in a microchannel solar collector is studied experimentally. The exchanger is composed of 16 micro-channel hydraulic diameters of 1 mm and a glass or quartz cover with a surface area of 25 cm2. Solar radiation is simulated by a halogen lamp. The experimental set-up includes a solar meter, pressure, and temperature sensors, and it is allowed to control the flow. The nanofluid is a solution of water containing a 0.01%, 0.05%, 0.1%, and 0.5% weight fraction, respectively, of the carbon nanotubes, which are 9.2 nm in diameter and 1.5 µm in length. Viscosity and density are measured experimentally. The evolution of efficiency and the pressure drop are presented according to the Reynolds number and are compared with the results obtained with distilled water.