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化工学报  2015 

新型喷嘴R404a闪蒸瞬态喷雾冷却传热特性

DOI: 10.11949/j.issn.0438-1157.20150289, PP. 100-105

Keywords: 闪蒸喷雾冷却,激光皮肤手术,膨胀腔喷嘴,瞬态传热,R404a

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Abstract:

制冷剂闪蒸瞬态喷雾冷却在激光治疗血管性皮肤病手术中得到广泛应用,主要用于激光照射前选择性地冷却表皮。本文搭建了喷雾冷却实验台,设计不同长径比膨胀腔新型透明喷嘴,应用薄膜热电偶瞬态温度快速测量技术和杜哈梅尔定理计算方法对比分析了膨胀型喷嘴和传统直管型喷嘴应用低沸点的新型制冷剂R404a的闪蒸瞬态喷雾冷却表面动态传热特性。应用高速摄像仪和采用背光法对新型喷嘴膨胀腔内部制冷剂流动形态进行观察,发现制冷剂液体在膨胀腔内首先发生一次闪蒸破碎,剧烈相变产生大量气泡,可导致液滴温度在喷嘴内部大幅降低,而直管型喷嘴制冷剂只在喷嘴喷出后才形成闪蒸喷雾并降温。因此,膨胀腔型喷嘴比直管喷嘴具有更佳的冷却效果,能够产生更低的冷却温度,更高的热通量、传热系数和换热量。膨胀腔长径比是影响此类喷嘴喷雾冷却效果的关键因素,在长径比1:2时其冷却能力最强、有效冷却时间最长。

References

[1]  Schneider B V, Mitsuhashi Y, Schnyder U W. Ultrastructural observations in port wine stains [J]. Arch. Dermatol .Res., 1988, 280(6): 338-345.
[2]  Chapas A M, Eickhorst K, Geronemus R G. Efficacy of early treatment of facial port wine stains in newborns: a review of 49 cases [J]. Laser Surg .Med., 2007, 39 (7): 563-568.
[3]  Kelly K M, Nelson J S. Update on the clinical management of port wine stains [J]. Laser Med. Sci., 2000, 15 (4): 220-226.
[4]  Nelson J S, Milner T E, Anvari B, Tanenbaum B S, Kimel S, Svaasand L O, Jacques S L. Dynamic epidermal cooling during pulsed laser treatment of port-wine stain: a new methodology with preliminary clinical evaluation [J]. Arch Dermatol, 1995, 131 (6): 695-700.
[5]  Nelson J S, Milner T E, Anvari B, Tanenbaum B S, Svaasand L O, Kimel S. Dynamic epidermal cooling in conjunction with laser-induced photothermolysis of port wine stain blood vessels [J]. Laser Surg Med., 1996, 19 (2): 224-229.
[6]  Chang C J, Anvari B, Nelson J S. Cryogen spray cooling for spatially selective photocoagulation of hemangiomas: a new methodology with preliminary clinical reports [J]. Plast Reconstr Surg., 1998, 102 (2): 459-463.
[7]  Chen J K, Ghasri P, Aguilar G, van Drooge A M, Wolkerstorfer A, Kelly K M, Heger M. An overview of clinical and experimental treatment modalities for port wine stains [J]. J. Am. Acad. Dermatol., 2012, 67(2):289-304.
[8]  Aguilar G, Choi B, Broekgaarden M, Yang O, Yang B, Ghasri P, Chen J K, Bezemer R, Nelson J S, van Drooge A M, Wolkerstorfer A, Kelly K M, Heger M. An overview of three promising mechanical, optical, and biochemical engineering approaches to improve selective photothermolysis of refractory port wine stains [J]. Ann. Biomed. Eng., 2012, 40 (2): 486-506.
[9]  Dai T, Yaseen M A, Diagaradjane P, Chang D W, Anvari B. Comparative study of cryogen spray cooling with R-134a and R-404a: implications for laser treatment of dark human skin [J]. J. Biomed. Opt., 2006, 11 (4): 041116.
[10]  Zhou Z, Chen B, Wang Y, Guo L, Wang G. An experimental study on pulsed spray cooling with refrigerant R-404a in laser surgery [J]. Appl. Therm. Eng., 2012, 39: 29-36.
[11]  Zhou Z F, Wu W T, Chen B, Wang G X, Guo L J. An experimental study on the spray and thermal characteristics of R134a two-phase flashing spray [J]. Int. J. Heat and Mass Tran., 2012, 55(15/16): 4460-4468.
[12]  Zhou Zhifu (周致富), Xin Hui (辛慧), Chen Bin (陈斌), Wang Guoxiang (王国祥). Evaporation characteristics of a single droplet in laser treatment of port wine stain in conjunction with cryogen spray cooling [J]. Chinese J. Lasers (中国激光), 2008, 35(6): 952-956.
[13]  Zhou Zhifu (周致富), Wu Weitao (吴威涛), Gong Zheng (龚政), Wang Guoxiang (王国祥), Chen Bin (陈斌), Wang Yueshe (王跃社). An experimental study on the dynamics of atomization and heat transfer in flashing transient spray with refrigerant R134a [J]. J. Eng. Thermophysics (工程热物理学报), 2011, 32(6): 977-980.
[14]  Zhou Zhifu (周致富), Wu Weitao (吴威涛), Wang Guoxiang (王国祥), Chen Bin (陈斌), Gong Zheng (龚政). Thin-film thermocouples for rapid measurement of transient surface temperature in cryogen spray cooling [J]. CIESC Journal (化工学报), 2011, 62(11): 2691-2695.
[15]  Zhou Zhifu (周致富), Wang Rui (王锐), Wang Guoxiang (王国祥), Guo Liejin (郭烈锦), Chen Bin (陈斌), Wang Yueshe (王跃社). Effect of nozzle size on the surface heat transfer dynamics during cryogen spray cooling in dermatologic laser surgery [J]. Chinese J. Lasers (中国激光), 2012, 39(3): 1-7.
[16]  Xin Hui (辛慧), Zhou Zhifu (周致富), Wang Guoxiang (王国祥), Chen Bin (陈斌), Wang Yueshe (王跃社). Evaporation characteristics of single R404a droplet in laser treatment of PWS in conjunction with cryogen spray cooling [J]. Chinese J. Lasers (中国激光), 2009, 36(10): 2691-2695.
[17]  Torres J H, Nelson J S, Tanenbaum B S, Milner T E, Goodman D M, Anvari B. Estimation of internal skin temperatures in response to cryogen spray cooling: implications for laser therapy of port wine stains [J]. IEEE J. Sel. Top Quant, 1999, 5(4): 1058-1065.
[18]  Tunnell J W, Torres J H, Anvari B. Methodology for estimation of time-dependent surface heat flux due to cryogen spray cooling [J]. Ann. Biomed. Eng., 2002, 30(1): 19-33.
[19]  Franco W, Liu J, Wang G X, Nelson J S, Aguilar G. Radial and temporal variations in surface heat transfer during cryogen spray cooling [J]. Phys. Med. Biol., 2005, 50(2): 387-397.

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