Multi-layer membrane filtration is a widely used technology for separating and purifying different components ofa liquid mixture. This technique involves passing the liquid mixture through a series of membranes with d...Multi-layer membrane filtration is a widely used technology for separating and purifying different components ofa liquid mixture. This technique involves passing the liquid mixture through a series of membranes with decreasing pore sizes, which allows for the separation of different components according to their molecular size. Thisstudy investigates the filtration process of a fluid through a two-dimensional porous medium designed forseawater desalination. The focus is on understanding the impact of various parameters such as the coefficientof friction, velocity, and the number of layers on filtration efficiency. The results reveal that the number of layersplays a crucial role in desalination, with an increase in layers leading to enhanced filtration quality, following apower law relationship. The study explores the influence of the coefficient of friction on filtration performance,emphasizing its significant effect on the number of particles filtered over time. Additionally, the role of the initialvelocity in filtration efficiency is examined, showing distinct effects at both high and low velocities. Biofouling isidentified as a factor influencing filtration, with an initial increase in filtered particles followed by a decline due toparticle accumulation in pores.展开更多
The exergy losses and thermodynamic efficiency of MSF plant with brine recirculation are discussed bymeans of temperature difference functions proposed by the auther.In a MSF plant,the irreversible losses are found ma...The exergy losses and thermodynamic efficiency of MSF plant with brine recirculation are discussed bymeans of temperature difference functions proposed by the auther.In a MSF plant,the irreversible losses are found mainly in irreversible heat-transfer and flash evaporationprocesses.However,the basic variables are the temperature drop from stage to stage and the temperaturedifferences between flashed vapor and cooling water.In this paper,the flash temperature difference func-tion,the heat transfer temperature difference function and the total temperature difference function are sug-gested.The proposed temperature difference functions of MSF plant provide a convenient tool to analyse theirreversible behavior and evaluate the exergetic efficiency of this system,because without such improvement thecalculation of the exergetic efficiency of a MSF plant according to the classical formula will be not onlyinconvenient but also insignificant.As a result of present analysis,the reasonable parameters based on theenergy consumption are easily chosen.The above-mentioned principles are confirmed by commercial plants and a pilot plant in Tianjin.展开更多
Using Object-oriented design and a new programming language JAVA, a physically-based model was built to simulate the hydrological, alkalization/de-alkalization and salinization/desalinization processes in soil. Furthe...Using Object-oriented design and a new programming language JAVA, a physically-based model was built to simulate the hydrological, alkalization/de-alkalization and salinization/desalinization processes in soil. Furthermore, a process-based model was built to evaluate the dynamics of four herbaceous ecosystems (including dynamics of above-ground biomass, below-ground biomass, and litter biomass), each dominated by Aneurolepidium chinense (Trin.) Kitag., Chloris virgata Sw., Puccinellia tenuiflora (Turcz.) Scribn. et Merr. and Suaeda glauca Bunge. This model is a daily-time step model, suitable for simulating hydrological, alkalization/de-alkalization and salinization/desalinization processes of heterogeneous soil, and growth dynamics of different grassland communities. With climatic data and experimental data of Changling Experimental Site in Jilin Province, the soil moisture content (in 1991, 1996, 1997 and 1998), soil salt concentration, exchangeable cation percentage and pH in soil and growth dynamics of these four sorts of grassland communities (in 1991) were simulated and the results were verified to be in accord with observed data.展开更多
文摘Multi-layer membrane filtration is a widely used technology for separating and purifying different components ofa liquid mixture. This technique involves passing the liquid mixture through a series of membranes with decreasing pore sizes, which allows for the separation of different components according to their molecular size. Thisstudy investigates the filtration process of a fluid through a two-dimensional porous medium designed forseawater desalination. The focus is on understanding the impact of various parameters such as the coefficientof friction, velocity, and the number of layers on filtration efficiency. The results reveal that the number of layersplays a crucial role in desalination, with an increase in layers leading to enhanced filtration quality, following apower law relationship. The study explores the influence of the coefficient of friction on filtration performance,emphasizing its significant effect on the number of particles filtered over time. Additionally, the role of the initialvelocity in filtration efficiency is examined, showing distinct effects at both high and low velocities. Biofouling isidentified as a factor influencing filtration, with an initial increase in filtered particles followed by a decline due toparticle accumulation in pores.
文摘The exergy losses and thermodynamic efficiency of MSF plant with brine recirculation are discussed bymeans of temperature difference functions proposed by the auther.In a MSF plant,the irreversible losses are found mainly in irreversible heat-transfer and flash evaporationprocesses.However,the basic variables are the temperature drop from stage to stage and the temperaturedifferences between flashed vapor and cooling water.In this paper,the flash temperature difference func-tion,the heat transfer temperature difference function and the total temperature difference function are sug-gested.The proposed temperature difference functions of MSF plant provide a convenient tool to analyse theirreversible behavior and evaluate the exergetic efficiency of this system,because without such improvement thecalculation of the exergetic efficiency of a MSF plant according to the classical formula will be not onlyinconvenient but also insignificant.As a result of present analysis,the reasonable parameters based on theenergy consumption are easily chosen.The above-mentioned principles are confirmed by commercial plants and a pilot plant in Tianjin.
文摘Using Object-oriented design and a new programming language JAVA, a physically-based model was built to simulate the hydrological, alkalization/de-alkalization and salinization/desalinization processes in soil. Furthermore, a process-based model was built to evaluate the dynamics of four herbaceous ecosystems (including dynamics of above-ground biomass, below-ground biomass, and litter biomass), each dominated by Aneurolepidium chinense (Trin.) Kitag., Chloris virgata Sw., Puccinellia tenuiflora (Turcz.) Scribn. et Merr. and Suaeda glauca Bunge. This model is a daily-time step model, suitable for simulating hydrological, alkalization/de-alkalization and salinization/desalinization processes of heterogeneous soil, and growth dynamics of different grassland communities. With climatic data and experimental data of Changling Experimental Site in Jilin Province, the soil moisture content (in 1991, 1996, 1997 and 1998), soil salt concentration, exchangeable cation percentage and pH in soil and growth dynamics of these four sorts of grassland communities (in 1991) were simulated and the results were verified to be in accord with observed data.
