與能源相關之熱傳問題及CIS薄膜太陽能電池吸光層之研究

Study of the heat transfer problems and the CuInSe2 thin film solar cell p-type absorption layer related to energy

余學杰(Hsueh-Chieh Yu)

指導教授 ： 黃景良

崑山科技大學/工程學院/機械與能源工程研究所/博士(2010年)

https://doi.org/10.6828/KSU.2010.00073

摘要

1.本論文研究主要是為了獲得足夠的證據以證實應用PTRC模型於複合壁二維穩態問題之不正確性，本論文將對圓管複合壁二維穩態問題，利用CFD軟體來分析所得熱傳率和溫度分佈的結果，與使用簡單的一維PTRC模型的結果作比較，由兩者之間產生極大的誤差以證明其不正確性。此外，本論文發展出之一維各自串聯熱阻迴路（SSTRC）模型作為取代PTRC模型作簡單可靠的工程計算。由SSTRC模型所生結果與數值解比較所得的誤差率，來尋求SSTRC模型在何種條件下的適用性。
2.對於有包覆與無包覆絕熱材料的管路，被大量用於現代的工業界與建築物中，由於熱輻射方程式包含了溫度四次方的計算，造成在數學上的分析非常複雜。所以，大部分的專家和學者認為，基於以往的經驗，若絕熱表面與外界環境之間的溫差非常小，則之間的熱輻射因素可被忽略，以簡化分析。因此，許多熱傳遞學或冷凍空調理論等教科書裡的絕熱例題或是實際的商業封裝絕熱設計，常常忽略了熱輻射效應。然而，本文將證明在某些條件下熱輻射效應不可被忽略。本文發展了一個專用的LabVIEW程式來計算考慮熱輻射之有包覆與無包覆絕熱材料的管路，結果顯示，在低空氣對流熱傳係數與高表面放射率的薄絕緣層條件底下，若忽略了熱輻射效應將導致不正確的絕熱設計；此外，本文也說明了較小的表面放射率可有很大程度地提升絕熱效果。
3.對於CIS薄膜太陽能電池吸光層之研究，是以合金與硒化方式製備CuInSe2，先以Cu/In薄膜疊層經退火熱處理形成Cu/In合金，再做硒化熱處理以形成CuInSe2為主題。Cu/In薄膜是以Sputter濺鍍方式製備，分別以Bi-layer、Multi-layer以及Co-sputter的方式濺鍍完成三種不同製程Cu/In膜層試片，接著以自行研發之硒化製具使用Se powder做硒化熱處理後，形成CIS Solar Cell之吸光層-CuInSe2.，在這三種不同疊層製程中，以Co-sputter疊層製備Cu/In膜層，接著以150℃做合金處理，再以550℃做硒化製程完成的CuInSe2試片，其膜層披覆性有較優之表現，且在XRD分析圖中，CuInSe2在結晶上的優選方向也有較佳的強度表現，二次相的形成也相對較少。

關鍵字

複合壁 ； 熱阻 ； PTRC模型 ； SSTRC模型 ； 不正確性 ； 熱傳特性 ； 圓管 ； 隔熱材厚度 ； 圖控程式 ； 高結晶性 ； CIS ； 濺鍍 ； 合金 ； 硒化 ； 疊層

並列摘要

1.This study is to prove that two-dimensional steady-state heat-transfer problems of composite circular pipes can not be appropriately solved by the conventionally one-dimensional Parallel Thermal Resistance Circuits (PTRC) model because its interface temperatures are not unique. Thus PTRC model is definitely different from its conventional recognized analogy, Parallel Electrical Resistance Circuits (PERC) model, which has unique node electric voltages. Two typical composite circular pipe examples are solved by CFD software, and the numerical results are compared with those obtained by PTRC model. This shows that PTRC model generates large error, thus this conventional model, introduced in most heat transfer text books, can not be applied to two-dimensional composite circular pipe. On the contrary, an alternative one-dimensional Separately Series Thermal Resistance Circuit (SSTRC) model is proposed and applied to the two-dimensional composite circular pipe with isothermal boundaries, and the acceptable results are returned.
2.Study of the non-insulated and insulated ducts are commonly applied in the industries and various buildings, because the heat radiation equation contains the 4th order exponential of temperature which is very complicate in calculations. Most heat transfer experts recognized from their own experiences that the heat radiation effect can be ignored due to the small temperature difference between insulated and non-insulated surface and surroundings. This paper studies in detail to check the inaccuracies of heat transfer characteristics non-insulated and insulated duct by comparing the results between considering and neglecting heat radiation effect. It is found that neglecting the heat radiation effect is likely to produce large errors of non-insulated and thin-insulated ducts in situations of ambient air with low external convection heat coefficients and larger surface emissivity, especially while the ambient air temperature is different from that of surroundings and greater internal fluid convection coefficients. It is also found in this paper that using greater duct surface emissivity can greatly improve the heat exchanger effect and using smaller insulated surface emissivity can obtain better insulation.
3.Study of the CuInSe2 thin film solar cell P-type absorption layer related, the formation of CuInSe2 is based on the Cu/In alloy and selenization processes. First of all, the Cu and In layers is formed by the Bi-layer, Multi-layer and the Co-sputter sputtering processes, respectively. Then annealing process of Cu and In layers is carried out to form the Cu/In alloy; And the CuInSe2 thin film is formed through the selenization heat treatment of this Cu/In alloy. The selenization heat treatment is processed with Se powder inside vacuum quartz tube to form the CuInSe2 absorption layer. Among above three different sputtering processes, the best preparation of Cu/In alloy is carried out through the Co-sputter process with 150℃annealing, and then processed through 550℃ selenization leading to the best formation of CuInSe2. This CuInSe2 absorption layer obtained by Co-sputter method under above processes has better performance; its XRD analysis diagram shows that the growth direction of crystal structure in CuInSe2 providing better intensity and less secondary phase of CuxSey and InxSey.

並列關鍵字

PTRC model ； SSTRC model ； thermal resistance ； composite circular pipe ； inaccuracy ； Insulation ； non-insulation ； circular duct ； heat radiation ； heat convection ； emissivity ； CIS ； Bi-layer ； Multi-layer ； Co-sputter ； sputtering ； heat treatment ； selenization

參考文獻

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