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Hasil Pencarian

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Sri Ismarwanti
Abstrak :
ABSTRAK
Pelajaran penting dari kecelakaan parah yang terjadi di pembangkit listrik tenaga nuklir Fukushima Daiichi Jepang menunjukkan bahwa panas sisa hasil peluruhan yang dibangkitkan dari bahan bakar nuklir bekas harus dapat didinginkan dengan baik. Dalam rangka menyerap panas sisa hasil peluruhan saat terjadi kecelakaan yang dipicu oleh kejadian station blackout, maka perlu dipertimbangkan penggunaan teknologi heat pipe tanpa wick (two-phase closed thermosyphon) dengan orientasi vertical sebagai sistem pendingin pasif di kolam penyimpanan bahan bakar nuklir bekas. Tujuan penelitian ini adalah untuk mengetahui karakteristik termal berupa pengaruh dari initial pressure, filling ratio, dan beban kalor pada unjuk kerjavertical two-phase closed thermosyphon yang akan digunakan sebagai sistem pendingin pasif di kolam penyimpanan bahan bakar nuklir bekas. Metode yang dilakukan dalam penelitian ini adalah dengan melakukan studi secara eksperimental dan simulasi menggunakan perangkat lunak RELAP5/MOD3.2. Vertical two-phase closed thermosyphon terbuat dari Cooper dengan geometri sebagai berikut: diameter dalam 0,1016 m, diameter luar 0,1031 m, dan panjang 6 m. Thermosyphon ini terdiri atas bagian evaporator, adiabatic dan condenser dengan rasio panjang yang sama. Air bebas mineral digunakan sebagai fluida kerja di dalamnya. Pembuangan kalor pada sisi condenser menggunakan air pendingin di dalam water jacket yang dipertahankan temperatur dan laju aliran volumetriknya. Dari eksperimen diperoleh hambatan termal terkecil sebesar 0,0151 C/W pada pengujian dengan filling ratio 80%, beban kalor 2500 W, temperatur air pendingin 26 C, laju aliran volumetrik pendingin 4 liter/menit, dan initial pressure -74 cm Hg. Hasil simulasi menunjukkan bahwa pemodelan yang dibangun dengan menggunakan perangkat lunak RELAP5/MOD3.2 menghasilkan distribusi temperatur yang hampir sama dengan eksperimen, sehingga dapat digunakan untuk simulasi selanjutnya dengan parameter yamg berbeda. Diharapkan hasil yang didapatkan dari eksperimen dan simulasi ini dapat menambah pengetahuan untuk mengetahui manajemen termal keselamatan nuklir bila terjadi station blackout.
ABSTRACT
The valuable lesson from a severe accident occurring in a nuclear power plant Fukushima Daiichi in Japan showed that the residual heat generated from the decay products of spent nuclear fuel must be cooled properly. The use of heat pipe technology without a wick (two-phase closed thermosyphon) with a vertical orientation as a passive cooling system in a spent fuel storage pool needs to be considered to absorb the decay heat during an accident triggered by station blackout.The purpose of this study was to determine the thermal characteristics such as the effect of the initial pressure, filling ratio, and the heat load on the performance of vertical two-phase closed thermosyphon to be used as a passive cooling system in a spent fuel storage pool. The method employed in this research were to conduct experimental and simulation studies using software RELAP5/MOD3.2. Vertical two-phase closed thermosyphon made of Copper with geometry as follows: an inside and outer diameter are 0.1016 m and 0.1031 m, respectively and 6 m long. Thermosyphon consists of the evaporator, adiabatic and condenser with the same length ratio. It uses demineralized water as the working fluid. Disposal of heat on the condenser side using cooling water in the water jacket that kept the temperature and volumetric flow rate. From the experiments showed that the smallest thermal resistance by 0.0151 ⁰C/W on testing by filling ratio of 80%, the heat load of 2500 W, cooling water temperature 26 ⁰C, the volumetric flow rate coolant4 liters/minute, and the initial pressure - 74 cm Hg. The simulation results show that the modeling software built using RELAP5 / MOD3.2 produce temperature distribution similar to the experiment. Expected results obtained from experiments and simulations can add knowledge to determine the thermal management of nuclear safety in station blackout
2016
T45938
UI - Tesis Membership  Universitas Indonesia Library
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Mukhsinun Hadi Kusuma
Abstrak :
Current cascade solar desalination systems can convert sea water into fresh water, but they can only produce small quantities. To produce more fresh water, there is a solution that can be applied, i.e. modification of the existing desalination system by adding thermosyphons. The objective of this research is to design a cascade solar desalination system with integrated thermosyphons and to establish its ability to produce fresh water. The experimental study was conducted by adding an aluminum absorber plate as a heat absorber in the upper tub, and nine copper thermosyphons with each length of 60 cm in the bottom of the tub. Thermosyphons with an inclination angle of 15° were used as a solar energy absorber and heat enhancer for sea water. The experiment was performed with varying sea water flow rates of 3600, 7200, and 10800 mL/h, and levels of sea water in the upper tub of 2, 3, and 4 cm. To compare the amount of fresh water obtained from the utilization of the thermosyphons, we also used the cascade solar desalination system without the thermosyphons. The results show that the cascade solar desalination system with integrated thermosyphons was able to produce an average amount of fresh water of 38.6 mL/h, with an average daily thermal efficiency of 18.78%. On the other hand, the same system without the thermosyphons produced on average 9.9 mL/h of fresh water, with an average daily thermal efficiency of 8%. The results indicate that the use of thermosyphons in the cascade solar desalination system can increase fresh water productivity by up to 3.89 times, and increase the thermal efficiency of the system by up to 2.35 times.
Depok: Faculty of Engineering, Universitas Indonesia, 2018
UI-IJTECH 9:2 (2018)
Artikel Jurnal  Universitas Indonesia Library