本文選題：干燥　切入點：模型　出處：《農(nóng)業(yè)工程學(xué)報》2017年17期 　論文類型：期刊論文

【摘要】：為了研究污泥的低溫干燥動力學(xué)特性,以薄層污泥為研究對象進(jìn)行了低溫干燥試驗,探討了溫度、薄層厚度以及風(fēng)速對污泥水分比和干燥速率的影響,并對低溫干燥參數(shù)進(jìn)行了優(yōu)化。結(jié)果表明:污泥低溫干燥過程主要由升速和降速段組成,其中降速階段存在第一、第二降速階段;不同低溫干燥條件下的第二臨界含水率變化不大,大致在0.5 g/g(干基)附近。使用決定系數(shù)R2、卡方χ2及均方根誤差RMSE對6種常用干燥模型進(jìn)行評價,結(jié)果表明Midilli模型的平均R2最大、平均χ2及RMSE最小,分別為0.999 8、2.46×10-5、0.004 2,是描述污泥低溫?zé)犸L(fēng)干燥的最優(yōu)模型。根據(jù)Fick第二定律和Arrhenius方程,得到5、10和15 mm厚度污泥在50~90℃熱風(fēng)干燥的水分有效擴散系數(shù)和活化能。正交試驗得到相對單位能耗最優(yōu)干燥工藝為:溫度90℃、風(fēng)速0.8 m/s、厚度10 mm,平均干燥強度最優(yōu)工藝為干燥溫度90℃、風(fēng)速0.8 m/s、厚度5 mm。試驗結(jié)果可為后續(xù)研究污泥熱泵干燥及太陽能-熱泵聯(lián)合干燥提供參考。
[Abstract]:In order to study the dynamic characteristics of sludge drying at low temperature, the effects of temperature, thickness of thin layer and wind speed on the moisture ratio and drying rate of sludge were studied. The parameters of low temperature drying were optimized. The results showed that the process of sludge drying at low temperature was mainly composed of increasing speed and decreasing speed. Under different low temperature drying conditions, the second critical moisture content changed little, about 0.5 g / g (dry base). The determination coefficient R2, chi-square 蠂 2 and root-mean-square error (RMSE) were used to evaluate six common drying models. The results show that the average R2 of Midilli model is the largest, the average 蠂 ~ 2 and RMSE are the smallest, which are 0.999 8 脳 10 ~ (-5) N _ (0.0042), respectively. It is the best model to describe the low temperature hot air drying of sludge. According to the second law of Fick and Arrhenius equation, The moisture effective diffusion coefficient and activation energy of sludge with thickness of 5 ~ 10 and 15 mm were obtained by hot air drying at 50 鈩，

本文編號：1563334