- 學位論文
添加咖啡渣製作的黏土磚隔熱效能評估及日照熱傳實驗研究
Experimental study on the thermal insulation performance and solar conduction of clay bricks manufactured with coffee ground
摘要
適宜的建材選擇能有效降低建築物的能源使用，本研究以建材常使用的黏土磚為例，考慮添加廢棄物製作環保磚材，並希望能提升隔熱效能。咖啡為現今很普遍的飲品，但飲用一杯咖啡約莫會產生20公克的咖啡渣，目前咖啡渣的處理仍以棄置為主，缺乏有效的再利用方式，本研究以咖啡渣做為磚材製做的添加物，評估添加咖啡渣對磚材相關物理及機械性質的改變情形。首先針對燒結溫度(950、1000、1050、1100、1150oC)及持溫時間(2小時及4小時)對於黏土磚的性質的影響先行了解，並且考慮咖啡渣的使用方法，一種是以粉末直接加入黏土原料中，另一種是處理成灰再混入，之後比較不同的添加比例10、20、30、40% (重量百分比)，討論容積密度、孔隙度、吸水率、抗壓強度、及熱傳導係數變化的情形。 初步實驗結果顯示，不論哪種形式，咖啡渣的確在燒結黏土試體中是有效的孔洞生成媒介，而且即使是少量的10%添加，也能促成磚材的隔熱效能提升。為符合CNS 382規範中的抗壓強度要求(30MPa)，相較於純黏土試體(抗壓強度平均為48.02 MPa)，添加量分別為10%、20%的咖啡渣灰樣本，抗壓強度平均為43.85 MPa及30.71 MPa；而三者的熱傳導係數，依序為0.95、0.74、0.41 W/mK，添加咖啡渣灰可有效降低熱傳導係數達22-56%。相較之下直接使用咖啡渣粉末，等量的添加比例下對降低熱傳導係數的效果更佳，但相對的抗壓強度值也降低許多。因為考量降低熱傳導效果的同時，必須達到一定抗壓強度的要求，因此選定以添加比例20%咖啡渣灰製成磚材，並與未添加的燒製黏土磚，各蓋出一棟縮尺模型，將兩棟模型房屋置於室外接受陽光照射，連續紀錄兩棟房屋內及室外的溫濕度變化情形及陽光輻射照度，並對結果加以比較分析。
並列摘要
The proper choice of construction materials can reduce the energy demand of buildings. In this research the use of waste on the production of eco-friendly clay bricks was investigated. Coffee is a popular beverage in our daily lives, but 20g coffee grounds are generated for each cup of coffee consumption. Right now the coffee grounds are mainly dumped without further applications. Therefore, this study aims to use coffee grounds as an additive to produce clay bricks with improved thermal insulation capacity. The effects of firing temperatures (950、1000、1050、1100、1150oC) and holding times (2hr and 4hr) on the physical- mechanical properties of clay bricks were examined first. Furthermore, the way of coffee grounds incorporated with clay bodies as form of powder or ash was investigated then. The fired sampled were compared with different replacement ratios (10、20、30、40% by wt.) and were characterized on bulk density, porosity, water absorption, compressive strength, and thermal conductivity. Results indicate that coffee ground is an effective pore-forming agent in the fired clay bodies and can promote the thermal insulation ability even with only 10% addition. To fulfill the compressive strength requirement (30 MPa) of CNS 382 for the first grade bricks, samples produced with 10% and 20% coffee ground ash have average compressive strength as 43.85 MPa and 30.71 MPa respectively, compared to reference bricks without coffee ground as 48.02MPa. The coefficient of thermal conductively was 0.95、0.74、0.41 W/mK accordingly. The addition of 10-20% coffee grounds ash leads to 22-56% reduction on thermal conductivity. Comparatively, the samples made directly by using coffee grounds powder have lower thermal conductivity; nevertheless, the compressive strength was cut down notably. With the focus on reducing thermal conductivity and maintaining sufficient compressive strength, two model houses were built and exposed under the outdoor sunlight to evaluate the thermal insulation capacity. One house was made by clay bricks added with 20% coffee ground ash, and the other was built with clay bricks without additive. The temperature、humidity and solar radiation were recorded continuously both inside and outside the houses. The results were compared and analysed.