小型熱聲冷凍機製造及研究 (2/3)

Abstract

本實驗第二年旨在利用微機電製程製作 熱聲冷凍儀之關鍵元件- stack 及驅動器 (driver)，並進行初步整體實驗探討。在本實驗 中已可明顯的觀察出熱聲冷凍效應的現象。熱 聲冷凍儀實驗中可達到8%之壓力振幅， 且使 用陶瓷stack 及兩種不同間隔之矽stack 為次熱 聲媒介。實驗結果顯示使用陶瓷stack，在壓力 振幅為6%、150Hz. 的條件下，stack 兩端溫差 有4.4 度的溫差。而在矽stack 方面， 兩種矽 stack 之溫差為0.8 度。在輸入聲波150 Hz.以 上時，因活塞發熱問題使得熱聲現象減低，若 能改善此影響，相信熱聲冷凍效應之表現會隨 著聲壓頻率增高而更好。

The second year effort is on the fabrication of the MEMS-based stack and the driver for the thermoacoustic device, as well as experimentally investigate its overall performance. The experiment clearly indicated success in obtaining thermoacoustic efforts. The pressure fluctuation is up to 8% of the mean pressure. Two stack designs were investigated: ceramic and the MEMS-based stack. Results show that for the ceramic stack, the pressure fluctuation is 6% at 150Hz., and the temperature difference is 4.4 degrees. For MEMS-based stack, the temperature difference is 0.8 degree. Heat accumulation problem of the driver piston is seen as the dominant source of heat input into the device.