闭式热泵干燥介质温湿度演化及对能耗的影响  

Medium temperature and humidity evolution of closed heat pump drying and its influence on energy consumption

作　　者：于贤龙 贾振超 慈文亮 张宗超 赵峰 YU Xian-long;JIA Zhen-chao;CI Wen-liang;ZHANG Zong-chao;ZHAO Feng(Shandong Academy of Agricultural Machinery Sciences,Jinan,Shandong 250100,China;Huang Huai Hai Key Laboratory of Modern Agricultural Equipment,Ministry of Agriculture and Rural Affairs,P.R.China,Jinan,Shandong 250100,China)

机构地区：[1]山东省农业机械科学研究院,山东济南250100 [2]农业农村部黄淮海现代农业装备重点实验室,山东济南250100

出　　处：《食品与机械》2023年第2期94-98,181,共6页Food and Machinery

基　　金：山东省农业科学院农业科技创新工程(编号:CXGC2022E16);国家自然科学基金项目(青年基金)(编号:32201691);山东省自然科学基金(编号:ZR2019PEE047)。

摘　　要：目的:解析闭式热泵干燥过程中物料脱水、干燥介质温湿度与耗能间的交互作用。方法:在60℃、10%RH的控制参数下,通过试验确定物料脱水特性、干燥介质温湿度演化及系统组件耗能。结果:干燥前期物料脱水速率较快,干燥1.5 h后物料脱除了整个干燥过程96%的水分;该阶段空气介质的相对湿度维持在24%以上,水分经蒸发器表面快速冷凝并排出,除湿能耗比最高可达1.03 kg/kW;热泵机组是干燥过程的主要耗能部件,其功耗随干燥介质温度的升高而升高;受干燥介质相对湿度降低和外部循环排热的影响,除湿能耗比在干燥后期迅速下降,在2 h后仅为0.004 kg/kW。结论:热泵干燥的能量利用与介质温湿度有密切关系,在物料含水率较高时干燥具有高除湿能耗比,而在干燥后期会随介质相对湿度值迅速下降;恒定的温湿度控制方法不利于闭式热泵系统在干燥后期的节能。Objective: This study aimed to resolve the interactions among the material dehydration, temperature and humidity of dry medium, and the energy consumption. Methods: The dehydration characteristics, temperature and humidity evolution of dry medium, and energy consumption of system component had been determined by testing under control parameters of 60 ℃ and 10% RH. Results: Dehydration rate of the materials was relatively fast in the early stage, 96 percent of the moisture was removed from the material after 1.5 hours of drying. At this stage, the relative humidity of drying medium remained above 24 percent, the moisture in drying medium was rapidly condensed and discharged from the surface of the evaporator, and the maximum value of specific moisture extraction ratio was 1.03 kg/kW. Heat pump unit was the main energy consuming part in the drying process, and its power increased with the temperature of the drying medium. The specific moisture extraction ratio decreased rapidly in the later drying stage, and its value was only 0.004 kg/kW after 2 hours. Conclusion: The energy utilization of heat pump drying was closely related to the temperature and humidity of medium and moisture content of material. Drying had a high specific moisture extraction ratio when the moisture content of material was high, and fell off as the relative humidity decrease. The constant temperature and humidity control method was not suitable for the energy saving of the closed heat pump system in the later drying stage.

关 键 词：闭式热泵 除湿干燥 介质温湿度 除湿能耗比 

分 类 号：TS203[轻工技术与工程—食品科学]