scholarly journals Analisis Pengaruh Penggantian Heating Element Terhadap Kinerja Air Preheater Type Ljungstrom Di PLTU Jateng 2 Adipala 1×660 MW

Eksergi ◽  
2019 ◽  
Vol 15 (2) ◽  
pp. 42
Author(s):  
Mulyono Mulyono ◽  
Anis Roihatin

<p>PLTU Jateng 2 Adipala menggunakan pemanas awal udara (air preheater) tipe Ljungstrom rotary regenerative. Pada bulan September 2017 telah dilakukan penggantian elemen pemanas pada air preheater A dan B yang semula tipe Double Undulated (DU) menjadi tipe Howden Closed (HC). Penggantian elemen dilakukan karena adanya endapan abu atau blocking elemen yang melebihi batas toleransi dan tidak dapat lagi dibersihkan menggunakan sootblower. Pengamatan dilakukan pada air preheater A dan B untuk kondisi sebelum dan sesudah penggantian elemen pemanas dengan parameter kinerja berupa kebocoran udara (AL), efisiensi sisi gas (GSE), dan X-ratio (Xr). Analisis kinerja dilakukan dengan menggunakan ASME PTC 4.3 sebagai landasan teori. Hasil perhitungan yang dilakukan AL terbaik pada elemen lama yaitu pada APH B sebesar 4,01% pada beban 100% dan AL terbaik pada elemen baru yaitu pada APH B sebesar 5,1443% pada beban 100%. Nilai GSE terbaik pada elemen lama yaitu pada APH B sebesar 69,3504% pada beban 100% dan nilai GSE terbaik pada elemen baru yaitu pada APH B sebesar 65,7484% pada beban 100%. Nilai Xr terbaik pada elemen lama yaitu pada APH B sebesar 0,7514% pada beban 100% dan nilai Xr terbaik pada elemen baru yaitu pada APH B sebesar 0,7229% pada beban 100%.</p>

Author(s):  
H. S. Kim ◽  
R. U. Lee

A heating element/electrical conduit assembly used in the Orbiter Maneuvering System failed a leak test during a routine refurbishment inspection. The conduit, approximately 100 mm in length and 12 mm in diameter, was fabricated from two tubes and braze-joined with a sleeve. The tube on the high temperature side (heating element side) and the sleeve were made of Inconel 600 and the other tube was stainless steel (SS) 316. For the filler metal, a Ni-Cr-B brazing alloy per AWS BNi-2, was used. A Helium leak test spotted the leak located at the joint between the sleeve and SS 316 tubing. This joint was dissected, mounted in a plastic mold, polished, and examined with an optical microscope. Debonding of the brazed surfaces was noticed, more pronounced toward the sleeve end which was exposed to uncontrolled atmospheric conditions intermittently. Initially, lack of wetting was suspected, presumably caused by inadequate surface preparation or incomplete fusion of the filler metal. However, this postulation was later discarded based upon the following observations: (1) The angle of wetting between the fillet and tube was small, an indication of adequate wetting, (2) the fillet did not exhibit a globular microstructure which would be an indication of insufficient melting of the filler metal, and (3) debonding was intermittent toward the midsection of the sleeve.


Author(s):  
Qiang Tai Zhou ◽  
Sai Yin Ye ◽  
Yuan Huang Ou-Yang ◽  
Nian Zu Gu

2017 ◽  
Author(s):  
Young Mun Lee ◽  
Heeyoon Chung ◽  
Seon Ho Kim ◽  
Hyeng Seob Bae ◽  
Hyung-Hee Cho

Alloy Digest ◽  
2013 ◽  
Vol 62 (10) ◽  

Abstract NIKROTHAL TE is a member of the Nikrothal family of alloys, which are one of two main types of electric-resistance alloys. Nickel-chromium (80Ni-20Cr, for example), developed around the turn of the century, was used as heating-element material in industrial furnaces and electric household appliances. Nikrothal alloys offer advantages in heating-element applications requiring very good mechanical properties in the hot state. This alloy is an attractive alternative to Nikrothal Alloys 40, 60, 70, and 80 (see Alloy Digest Ni-529, September 1997). This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on forming. Filing Code: Ni-710. Producer or source: Sandvik Heating Technology.


2015 ◽  
Vol 25 (5) ◽  
pp. 258-263
Author(s):  
Shinhee Jun ◽  
◽  
Wonjoo Lee ◽  
Young-Min Kong

Author(s):  
Xuhai Xiong ◽  
Daosheng Wang ◽  
Jian Wei ◽  
Pu Zhao ◽  
Rong Ren ◽  
...  

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