本論文主要在研究板鰭管式蒸發器之鰭片於結霜狀態下，受到強制對流作用時熱傳係數。論文內容包括數值分析及實驗兩部份。本研究以實驗擷取之溫度和霜層厚度數據，再配合反算法預估熱傳係數與環境條件的關係。

本研究運用拉氏轉換法(Laplace Transform Method)和有限差分法(Finite-Difference Method)，配合溫度量測值來解析二維暫態熱傳導方程式，以預測板鰭管式蒸發器之鰭片在強制對流作用下的熱傳係數。在反算過程中將以最小平方法(Least -Squares Scheme)來修正預估值，直至所求得於量測點之溫度值與其所對應點之量測溫度值之間的誤差甚小為止。一般而言，預測值的精確度對於溫度量測誤差極為靈敏，因此本文中也將探討溫度量測誤差對預測值的影響。本研究中之實驗，以自行設計之板鰭管式蒸發器配合相關設備來量測霜層厚度及鰭片上之溫度與管壁溫度。而後根據實驗數據，利用反算法來估算於強制對流作用下，板鰭管式蒸發器結霜狀態之熱傳遞係數。

The main task of the thesis is to estimate the heat transfer coefficient on the double plate finned-tube evaporator under frosting condition. Researches will include numerical and experimental works; the numerical work is to present the relationship between the thickness of frost and the heat transfer coefficient, and the experimental work is to obtain the temperature data.

The numerical method based on the hybrid scheme of the Laplace transform method and central different method in conjunction with the least-squares scheme is used to solve the two-dimensional inverse heat conduction problems for evaluating heat transfer coefficient. The least-squares minimization technique is applied to minimize the sum of the squares of the deviations between the calculated and curve-fitted temperature measurements. In the inverse heat conduction problem, slight inaccuracies in the measured interior temperatures can affect the accuracy of estimated the thermal properties. Thus the effect of measurement errors on the estimation of heat transfer coefficient will be investigated in the present analysis. A plate finned-tube evaporator is set up in conjunction with the other experimental equipment for measuring the frost thickness and tube temperature. The heat transfer coefficient and heat flux on the fin under frosting condition can be determined by using the present numerical method and the temperature measurements.

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