PERFORMANCE DETERIORATION OF THERMOSIPHON SOLAR FLAT PLATE WATER HEATER DUE TO SCALING

Article English OPEN
arunachala umesh chandavar (2011)
  • Publisher: IIUM Press, International Islamic University Malaysia
  • Journal: International Islamic University Malaysia Engineering Journal (issn: 1511-788X, eissn: 2289-7860)
  • Related identifiers: doi: 10.31436/iiumej.v12i3.157
  • Subject: TA1-2040 | scaling | Thermosiphon system | Engineering (General). Civil engineering (General) | instantaneous efficiency | H-W-B equation. | Thermosiphon system, scaling, instantaneous efficiency, H-W-B equation.

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<w:LsdException Locked="false" Priority="37" Name="Bibliography" /> <w:LsdException Locked="false" Priority="39" QFormat="true" Name="TOC Heading" /> </w:LatentStyles> </xml><![endif]--> <!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Times New Roman";} </style> <![endif]--> <!--StartFragment--> <div style="mso-element: para-border-div; border-top: solid windowtext 1.0pt; border-left: none; border-bottom: solid windowtext 1.0pt; border-right: none; padding: 6.0pt 0cm 6.0pt 0cm; margin-left: 21.6pt; margin-right: 21.6pt;"><p class="abstract" style="margin-top: 6.0pt; margin-right: 0cm; margin-bottom: 6.0pt; margin-left: 0cm; text-indent: .9pt;">The performance of Flat plate Solar Water Heater deteriorates within five to twelve years of their installation due to factors related to manufacturing, operating conditions, lack of maintenance etc. Especially, problem due to scaling is significant as it is based on quality of water used. The remaining factors are system dependent and could be overcome by quality production. Software<span style="letter-spacing: -.1pt;"> is developed by incorporating Hottel Whillier Bliss (H-W-B) equation to ascertain the effect of scaling on system efficiency in case of thermosiphon system. </span>In case of clean thermosiphon system, the instantaneous efficiency calculated at 1000 W/m<sup>2</sup> radiation is 72 % and it drops to 46 % for 3.7 mm scale thickness. The mass flow rate is reduced by 90 % for 3.7 mm scale thickness. Whereas, the average temperature drop of water in the tank is not critical due to considerable heat content in water under severe scaled condition.<span style="mso-spacerun: yes;">&nbsp; </span>But practically in case of major scale growth, some of the risers are likely to get blocked completely which leads to negligible temperature rise in the tank.</p> <p class="abstract" style="margin-top: 6.0pt; margin-right: 0cm; margin-bottom: 6.0pt; margin-left: 0cm; text-indent: .9pt;"><strong style="mso-bidi-font-weight: normal;"><em style="mso-bidi-font-style: normal;">ABSTRAK: </em></strong>Prestasi plat rata pemanas air suria merosot selepas lima hingga dua belas tahun<span style="mso-spacerun: yes;">&nbsp; </span>pemasangannya disebabkan faktor-faktor yang berkaitan dengan pembuatannya, cara kendaliannya, kurangnya penyelenggaraan dan sebagainya.<span style="mso-spacerun: yes;">&nbsp; </span>Terutama sekali, masalah disebabkan <em style="mso-bidi-font-style: normal;"><span style="font-family: &quot;Times New Roman Italic&quot;;">scaling</span></em><span style="font-family: &quot;Times New Roman Italic&quot;;"> </span>(tembunan endapan mineral) perlu diambil berat kerana ianya bergantung kepada kualiti air yang digunakan. Faktor-faktor selebihya bersandarkan sistem dan ia boleh diatasi dengan mempertingkatkan kualiti pembuatannya. Perisian komputer dihasilkan dengan menggunakan persamaan <span style="font-family: &quot;Times New Roman Italic&quot;; letter-spacing: -.1pt;">Hottel Whillier Bliss (H-W-B)</span><span style="letter-spacing: -.1pt;"> untuk menentukan<span style="mso-spacerun: yes;">&nbsp; </span>kesan </span><em style="mso-bidi-font-style: normal;"><span style="font-family: &quot;Times New Roman Italic&quot;; letter-spacing: -.1pt;">scaling</span></em><span style="letter-spacing: -.1pt;"> terhadap kecekapan sistem dalam termosifon. Dalam sistem termosifon bersih, kecekapan seketika dikira pada 1000 W</span>/m<sup>2 </sup>, pada kadar radiasi 72 % dan ianya jatuh kepada 46 % untuk ketebalan skala 3.7 mm. Kadar aliran jisim berkurangan sebanyak 90 % untuk ketebalan skala 3.7 mm. Manakala, penurunan suhu purata air di dalam tangki tidaklah kritikal, disebabkan oleh kandungan haba yang tinggi di dalam air di bawah keadaan<span style="mso-spacerun: yes;">&nbsp; </span>kerak yang teruk. Tetapi dalam kes tumbesaran kerak yang genting, sesetengah penaik akan tersumbat sepenuhnya, mengakibatkan peningkatan suhu di dalam tangki boleh diabaikan.</p></div> <!--EndFragment-->
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