尿残液是空间站环境控制与生命保障(环控生保)系统中尿液水分回收过程的副产物,具有高盐含量、强酸强氧化性的特点,进一步处理处置难度大.本文立足现有空间站水循环技术状态,充分考虑轻量化、高可靠的工程约束,提出采用间接加热气扫式膜蒸馏技术途径完成残液中的水分回收,同时完成减量化处理.建立该膜蒸馏形式的传热传质模型,分别考察了吹扫气体状态(温度、湿度、流量),膜材料性质(厚度、孔径、孔隙率),以及残液物质浓度等7个主要变量对蒸馏速率的影响规律,其中的孔隙率和进气湿度对蒸馏速率有相对更大的影响.针对尿残液的理化性质,筛选出13种耐受性疏水膜材料,开展膜蒸馏实验,实验所得趋势与理论预测一致,实验值与理论值的平均相对偏差为6.6％,验证了模型的有效性.研究为残液水分回收膜材料选择和技术开发提供了理论和实验基础.

Physical-chemical technology is used in the environmental control and life support systems(ECLSS) of the International Space Station(ISS) to realize the water recycling.During the process, part of the water will enter into the urine brine produced by urine distillation and thus cannot be recy-cled.Techniques that are capable of extracting water from urine brine would enhance the level of total water recovery, and therefore lower the frequency and cost of supply from the earth.The urine brine processing techniques focusing on water recovery was comprehensively reviewed in this paper.The characteristics of 8 technologies from 3 categories including the direct drying technology, the indirect drying technology and the separation drying technology were compared.Then the technology selection of water recovery from urine brine was proposed.In addition, the key points and difficulties in the re-search of water recovery technology was pointed out which may serve as a reference for future researches.

Presently, the traditional approach to removing plumule from lotus seed has several problems, i.e., low work efficiency, high labor intensity and safety issues. In this paper, a novel plumule removing technology is proposed, with the mechanism analysis of plumule removal process, design of the self-adaptive plumule removal mechanism and control system development. Firstly, a plumule removing technique based on the fluid injection principle is presented. The plumule is extruded and removed with a hollow needle by injecting compressed air. Then, a self-adaptive centering method is implemented to precisely centering the position of plumule with regards to lotus seeds of different sizes. The processing sequence is accomplished by the control system, which is composed of a human machine interface (HMI) and a programmable logical controller (PLC), aiming to coordinate and control mechanical actions in the process. Finally, the machine performance is experimentally evaluated by a number of tests, with the rate of successful separation being 73%. The result demonstrates the designed machine meets the requirements and thus effectively alleviate labor costs, maximize processing efficiency while still preserving the economic value of the lotus seeds.

为降低莲仁在钻削去心过程中的加工损耗,找出去心工艺参数对莲仁崩碎的影响规律,该文对莲仁钻削去心过程进行了力学分析、切削过程摸拟、试验测试和工艺参数优化研究.1)对莲仁钻削去心时的受力状态进行了力学分析,建立了莲仁钻削加工的力学模型,分析了莲仁钻削崩碎的主要因素为压辊夹紧力、钻头直径、钻头转速、钻头进给量和莲仁含水率等;2)应用DEFORM 3D软件对莲仁钻削加工过程进行了切削仿真,获得了不同工艺参数条件下钻削轴向力变化曲线以及莲仁应变云图,得到了各工艺参数对莲仁崩碎的影响规律,并找出了莲仁剥落的薄弱位置;3)用Kistler测力仪对莲仁钻削去心过程进行了钻削力测试,得到了莲仁在钻削过程中轴向力-时间曲线,以及切削速度、进给量、钻头直径等工艺参数对钻削轴向力的影响曲线,测试结果与仿真结果基本一致;4)基于所设计的莲仁去心试验台,用单因素试验法测试了含水率、压辊夹紧力、钻头速度、钻头进给量及钻头直径等工艺参数对莲仁崩碎率的影响规律,并在单因素试验结果的基础上,用正交优化试验法获得最优参数组合为莲仁含水率7.78％、钻头直径2.2 mm、压辊夹紧力38 N、钻头进给速度20 mm/s、钻头转速3000 r/min.研究结果可为莲仁钻削去心设备的设计提供参考.