摘要
制冷剂闪蒸瞬态喷雾冷却已经成为激光治疗葡萄酒色斑临床手术中重要的冷却辅助手段,能够保护表皮不受激光的热损伤,提高治疗激光能量,改善治疗效果。针对制冷剂闪蒸瞬态喷雾冷却表面温度快速准确测量的难点,建立了制冷剂闪蒸喷雾冷却实验系统,利用磁控溅射技术直接在被测表面沉积T型薄膜热电偶,对薄膜热电偶测量瞬态表面温度技术进行了详细研究,校核了薄膜热电偶的静态温度特性和动态反应时间,对测得的温度结果进行了巴特沃斯低通滤波处理,比较了滤波截止频率和采样率对滤波结果的影响。
Pulsed cryogen spray cooling （CSC） has become an effective method to protect the epidermis from non-specific thermal injuries in laser treatments of vascular malformation such as port wine stains. Cooling experiments with a skin phantom are usually conducted to quantify the heat transfer of CSC from a skin surface. Due to the high cooling ability of CSC and poor thermal conductivity of the skin phantom, the skin surface usually experiences a fast variation of the surface temperatures during CSC. It is therefore desirable to have a fast response surface thermal sensor to measure such temperature change. In traditional methods, commercial thermocouples of round or plate-shaped joints are buried on the surface or within the skin phantom in the experiments and usually give a poor response of the surface temperature. In this study, a fast response, thin film thermocouple （TFTC） of type T on a skin phantom made of epoxy or plastic glass is developed. The thin film thermocouple is manufactured by the Magnetron Spurting technique with a precise control of the compositions of Cu and Ni as well as the film thickness from 0.5 to 2 microns. A 0.05 micron thick of SiO2 protection layer is deposited on the TFTC as protection. Careful calibrations of TFTCs indicate that the thermoelectric property of the TFTCs agrees well with that of standard T-type thermocouples. The time constant of the TFTCs is about 1.2 ms, determined by pulsed laser heating experiments. Due to its small thermal capacity, the TFTC is sensitive to environmental fluctuations and the original temperature data show large noises. A low pass Butterworth （BW） filter is then introduced in the data acquisition system to remove such noises. Effect of the cut-off frequency and sample rate on the filtered temperature data has also been investigated and optimal cut-off frequencies and sample rates are recommended. A typical result for the temperature variation of the epoxy phantom surface during CSC is presented to illustrate the effectiveness of our TFTCs.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2011年第11期3060-3065,共6页
CIESC Journal
基金
国家自然科学基金项目(50821064)
西安交通大学交叉学科项目(2009xjtujc05)~~
关键词
闪蒸
制冷剂喷雾冷却
薄膜热电偶
表面温度测量
flashing
cryogen spray cooling
thin film thermocouple
surface temperature measurement
