【摘要】：閉路循環(huán)干燥是指干燥介質(zhì)在封閉系統(tǒng)中循環(huán)使用的干燥作業(yè),具有可回收溶劑、安全、環(huán)保、產(chǎn)品質(zhì)量好等顯著特點。熱泵是一種從低溫熱源吸收熱量,在較高溫度下放出大量可以被利用的熱量的裝置。熱泵與閉路循環(huán)干燥的有機結(jié)合,不僅可回收干燥尾氣中的大量熱量,而且可節(jié)省大量用于冷卻干燥尾氣的冷量,節(jié)能效果顯著,有廣闊的應(yīng)用前景。本文提出了以流化床為干燥器采用部分尾氣循環(huán)的閉路循環(huán)熱泵干燥流程;在分布板直徑為188mm的流化床內(nèi),以PVC為干燥物料,以空氣為流化、干燥介質(zhì),實驗研究了進風溫度和濕度對PVC流化干燥特性的影響,擬合得到了恒速段和降速段的干燥動力學(xué)模型分別為MR(28)a(10)bt和MR(28)exp(-ktn);用該模型計算了PVC流化干燥過程,對部分尾氣循環(huán)的閉路循環(huán)熱泵式流化床干燥過程進行了模擬分析,得到了循環(huán)比、熱泵工質(zhì)的蒸發(fā)溫度、冷凝溫度對干燥系統(tǒng)的COP、SMER的影響規(guī)律:蒸發(fā)溫度20℃時,冷凝溫度越高,干燥系統(tǒng)的C OP、SMER越小;冷凝溫度105℃時,蒸發(fā)溫度越高,干燥系統(tǒng)的C OP、SMER越大;蒸發(fā)溫度20℃,冷凝溫度75℃時,循環(huán)比增大,干燥系統(tǒng)的COP、SMER也越大。模擬計算的結(jié)果表明,在相同的操作條件下,與常規(guī)的閉路循環(huán)熱泵式流化床干燥系統(tǒng)相比,部分尾氣循環(huán)的閉路循環(huán)熱泵式流化床干燥系統(tǒng)的SMER更高,節(jié)能效果顯著。研究結(jié)果對促進閉路循環(huán)熱泵干燥過程的工業(yè)應(yīng)用有一定的理論和現(xiàn)實意義。
[Abstract]:Closed cycle drying refers to the drying operation in which the drying medium is recycled in the closed system. It has the remarkable characteristics of recoverable solvent, safety, environmental protection, good product quality and so on. Heat pump is a kind of device that absorbs heat from low temperature heat source and emits a large amount of heat which can be used at higher temperature. The organic combination of heat pump and closed loop drying can not only recover a lot of heat from the tail gas of drying, but also save a large amount of cooling for cooling and drying tail gas. In this paper, a closed circuit heat pump drying process using partial tail gas cycle in fluidized bed as dryer is proposed. In fluidized bed with diameter of distribution plate 188mm, PVC is used as drying material and air as fluidized medium. The effects of inlet air temperature and humidity on the drying characteristics of PVC fluidization were experimentally studied. The drying kinetics models of constant velocity section and low speed section were obtained as Mr (28) a (10) bt and Mr (28) exp (-ktn), respectively, and the drying process of PVC fluidized drying was calculated by this model. The drying process of closed circuit heat pump fluidized bed with partial tail gas cycle is simulated and analyzed. The effect of circulating ratio, evaporation temperature of heat pump working fluid and condensation temperature on COPSMER of drying system is obtained: the evaporation temperature is 20 鈩，

本文編號：2146942