WREF 2012 THE USE OF PCM FOR AMELIORATING THERMAL PERFORMANCE OF VEHICLE CABIN. Presenter: N. V. Lan

Transcription

1 WREF 2012 HE USE OF FOR AMELIORAING HERMAL PERFORMANCE OF VEHICLE CABIN Presenter: N. V. Lan

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3 I. WHY? 3

4 I. WHY? 4

5 I. WHY? Vehcles have been beng wdely used all around the world thanks to ther excellent convenence. hey are one of the means that consume a huge a mount of gasolne/ol everyday. Bllons of ltres of gasolne can be wasted durng traffc jam A large part of that huge amount s consumed for the ar condtonng attempt nsde cabns. 5

6 Heat enterng the cabn space ncludes: + From outsde through roof (solar rradaton, hot ambent ar) nsulator + From outsde through glass wndows thn flm coatng / curtan + From engnes nsulator / ventlaton I. WHY? In sunny whether (especally summer tme n tropcal countres) more heat may be ganed through the roof sde. hs paper suggests a soluton to reduce the solar heat gan through roof of vehcle cabns. 6

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8 I. WHA? Suggested method: addng n to the normal roof structure a layer of Phase Change Materal () whch has the ablty of absorbng the heat flow through the roof. 8

9 I. WHA? Fg. 1: Layer structure of normal vehcle Fg. 2: Novel desgn structure of the vehcle roof 9

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11 III. HOW? Fg. 3: Schematc dagram of the expermental set up 11

12 12 III. HOW? MAHEMAIC FORMULAION a 1 ex rad solar 0 x 1 metal h q Q x k 2 2 x ) (x, k d ) (x, C (1) (2) 3 1/ 1 ex Pr Gr X K 0.14 h s) 2(m / v f v s) 2(m / v f v h ex2 4 sky 4 1 rad q (3) (4) (5)

13 13 III. HOW? k k k k k k melt-max L melt-max melt-mn mn melt melt-max S L S melt-mn S Cp 2 Cp Cp ) ( H Cp Cp melt-max S- melt-max melt-mn L S meltmn melt-max melt-mn S- j desred j normal k desred k t 0 t desred normal par ar t 0 t desred par ar normal t ) ( t ) ( )dt.(.c m )dt.(.c m E E stop stop normal new E E 1 (%) (6) (7) (8) (9)

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15 IV. RESULS? Fg. 5: emperature responses of yellow roof models wth/wthout (no external wnd) 15

16 IV. RESULS? Fg. 6: emperature responses of yellow roof model wth/wthout (wth external wnd) 16

17 IV. RESULS? ABLE 3: EXPERIMEN RESUL COMPARISON Color External Wth 1 ( o C) 2 ( o C) ( o C) (%) wnd Black No Yes Black No No Grey Yes Yes Grey Yes No Grey No Yes Grey No No Yellow Yes Yes Yellow Yes No Yellow No Yes Yellow No No Whte No Yes Whte No No

18 IV. RESULS? ABLE 4: EFFEC OF MELING EMPERAURE OF Color External wnd Wth meltng temperature ( o C) Meltng perod (mn) (%) Grey No Yes Grey No Yes 39* Grey No Yes (* expermental condton) 18

19 IV. RESULS? ABLE 5: EFFEC OF LAEN HEA CAPACIY OF Color External wnd Wth Latent heat (kj/kg) Meltng perod (mn) (%) Grey No Yes Grey No Yes 88* Grey No Yes (* expermental condton) 19

20 IV. RESULS? ABLE 6: EFFEC OF AMBIEN EMPERAURE Color External wnd Wth Ambent temperature ( o C) (%) Grey No Yes 25* Grey No Yes Grey No Yes (* expermental condton) 20

21 IV. RESULS? ABLE 7: EFFEC OF EXERNAL WIND SPEED Color External wnd Wth Wnd speed (m/s) Wnd speed (km/h) (%) Grey Yes Yes 5* Grey Yes Yes Grey Yes Yes (* expermental condton) 21

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23 V. CONCLUSION? A new desgn of roofng for vehcles has been done by nsertng a layer of to the roof structure n order to slow down the heat transfer process through the roof to the cabn space. Both expermental and numercal results have shown that the new desgn has a better thermal performance than the normal roof structure of the avalable vehcles. In the mentoned experment condton, the new desgn may help to reduce up to about 40% of the energy amount requred for coolng down the heat enterng nto the cabn from the roof. 23

24 V. CONCLUSION? he savng rate could be even much hgher n case external wnd s present due to natural wnd or movement of the car n use. he paper also suggests condtons for choosng sutable type n real desgn accordng to the weather condton such as ambent temperature, meltng temperature and latent heat capacty. hs s a promsng desgn whch could be massvely produced due to ts smple structure and reasonable prce. 24

25 HANK YOU! 25