Rancang Bangun Heater Element Segment pada Rangkaian Sistem Reactor Cavity Cooling RDNK

RANCANG BANGUN HEATER ELEMENT SEGMENT PADA RANGKAIAN SISTEM REACTOR CAVITY COOLING RDNK. Proses pendinginan secara pasif menjadi perhatian khusus sejak kecelakaan PLTN Fukushima dan TMI-2, kecelakaan tersebut diakibatkan oleh gagalnya sistem pendingin aktif dimana pompa tidak berfungsi. Kemudian, aliran sirkulasi alam sebagai prinsip kerja sistem pendingin pasif juga digunakan pada model pendinginan di celah antara dinding luar Reactor Pressure Vessel (RPV) reactor High Temperature Gass Cooled Reactor (HTGR) dan beton penopang RPV. Riset terkait reactor cavity cooling system berbasis pendingin pasif dilakukan dengan membuat Untai Uji Reactor Cavity Cooling System-Reaktor Daya Non Komersial (RCCS-RDNK), namun saat dilakukan komisioning fungsi pemanasannya tidak optimal, temperatur yang ingin dicapai yaitu 300oC – 400oC pada permukaan simulator RPV HTGR tidak tercapai, sehingga dilakukan modifikasi pada sistem pemanas dengan heater element segments (HES) berbasis proses radiasi. Tujuan penelitian adalah untuk melakukan analisis pada pengujian pemanasan HES hasil konstruksi hingga mencapai temperatur optimal. Metode eksperimen dilakukan dengan menghidupkan heater dan merekam perubahan temperatur pada titik pengukuran di bagian permukaan insulator brick (BRICK), permukaan dalam RPV (RPVD), permukaan luar RPV (RPVL) dan udara luar. Hasil pengujian menunjukkan, secara umum capaian maksimal temperatur pada bagian permukaan RPV sekitar 400oC, dengan temperatur permukaan brick sekitar 700oC. Hal ini menunjukkan bahwa, konstruksi pemanas HES dapat beroperasi optimal dan memenuhi kriteria simulasi pendingin pada RCCS HTGR.

Enhanced ion–cavity coupling through cavity cooling in the strong coupling regime

Incorporating optical cavities in ion traps is becoming increasingly important in the development of photonic quantum networks. However, the presence of the cavity can hamper efficient laser cooling of ions because of geometric constraints that the cavity imposes and an unfavourable Purcell effect that can modify the cooling dynamics substantially. On the other hand the coupling of the ion to the cavity can also be exploited to provide a mechanism to efficiently cool the ion. In this paper we demonstrate experimentally how cavity cooling can be implemented to improve the localisation of the ion and thus its coupling to the cavity. By using cavity cooling we obtain an enhanced ion–cavity coupling of $$2\pi \times (16.7\pm 0.1)$$ 2 π × ( 16.7 ± 0.1 ) MHz, compared with $$2\pi \times (15.2\pm 0.1)$$ 2 π × ( 15.2 ± 0.1 ) MHz when using only Doppler cooling.

A Toolbox of Hardware and Digital Solutions for Increased Flexibility

The power generation market has been changing rapidly with the injection of an ever increasing usage of renewable power sources. The cyclic and highly unpredictable nature of power generation output from renewable sources is forcing Gas Turbine (GT) operators to significantly increase the operational flexibility of their engines. While the industry has been, for many years, developing and fielding solutions providing increased output at the high end of the operating range, the focus has shifted recently to solutions allowing for a safe decrease of the engines’ minimum operating load. The AutoTune (AT) system was introduced at last year’s Turbo Expo conference [5], and the challenges of developing a safe Extended Turndown add-on are detailed herein. Other digital and hardware solutions presented include Part Load Performance, decreased start-up time for both simple and combined cycle units, disc cavity cooling modulation and Exhaust Bleed. Increased ramp rate is addressed with the associated significant difficulty of maintaining the mechanical integrity of the rotors and casings. PSM has been working on a toolbox of both hardware and digital solutions to increase on GT operability both on the high and low ends of the load range and the technical issues faced are described in this paper.