竖管多效蒸发海水淡化系统的启动特性

建立大型竖管多效蒸发海水淡化系统的动态启动控制模型,通过数值分析研究,对系统的启动过程和启动特性进行理论探索.分析了初始原料海水流量以及最高饱和温度等运行参数的选择对系统启动过程的影响.研究了启动阶段,原料海水流量与系统的造水比以及启动时间之间的耦合影响;计算结果为原料海水流量的优化提供了依据.研究还表明,在启动之初,系统即可稳定地承担作为热源的低温核供热堆的额定产热量,显示该系统和核供热堆具有良好的耦合特性.建立的启动模型在经过实验验证加以完善之后,可以作为分析系统动态运行特性的理论基础.     

沸石膜在海水淡化及含盐废水处理中的应用

目前工业淡化技术主要采用有机高分子分离膜材料,但有机膜材料存在使用寿命短、易污染、生化稳定性低且再生困难等缺点,严重阻碍了淡化技术的发展。而化学稳定性好且脱盐分离性能优异的沸石膜可能成为海水淡化和复杂含盐废水处理中有机膜的替代材料。对利用新型沸石膜材料进行海水淡化和含盐废水处理的相关研究进行了综述,该类技术可以有效弥补有机膜脱盐技术中存在的不足。     

Practical Experience in Design and Operation of Liquid‐Liquid Extraction Processes

Liquid‐liquid (L/L) extraction is a standard unit operation in the phenol‐acetone process. Special applications are the extraction of phenol from process water and the removal of phenol from recycle cumene. Besides the standard equipment such as static mixers and horizontal settlers, centrifugal pumps are used for mixing and vertical settlers are operated for phase separation. This article covers some practical experience in design and operation with focus on using centrifugal pumps, maintain mass transfer in pipes and the design of vertical settlers. Gaps in knowledge about various phenomena such as the mass transfer in turbulent L/L pipe flow are pointed out.     

反渗透海水淡化中差动式能量回收装置的研究

研究了一种应用于中小型反渗透海水淡化装置的新型差动式能量回收装置.结果表明,使用本能量回收装置的日产10m3反渗透海水淡化装置的单位淡水能耗只有3.6kWh/m^3,不考虑高压泵及电机自身损耗的影响时,单位淡水能耗为2.3～2.7kWh/m^3,装置能耗显著降低,能量回收效率达到97%.此能量回收装置不需要其它附加增压设备,并且能有效改进由于阀门开闭导致系统压力波动而造成的淡水产量不稳定的问题,保护了反渗透膜、高压泵等系统内的重要设备.     

Thin film desalination plants and their role in water supply

Our investigation considers the advantages of thin film desalination plants (vertical, horizontal, combined) and their role in water supply.Evaporating horizontal thin film plants proved to be the most effective in economy and power engineering. This paper describes in detail the working processes in different types of pilot desalination plants within the wide range of parameters.As a result, a wide variety of applications of these processes is given.     

海水淡化浓盐水排放对环境的影响与零排放技术研究进展

回顾了目前常用的海水淡化技术及其应用现状,重点综述了海水淡化浓盐水排放对海洋环境的影响,分析了排放盐水的组分、盐度、热污染、腐蚀产物、化学清洗剂等对海洋环境和海洋生物的潜在影响,提出了相应的解决措施与解决方法,说明浓盐水零排放技术是解决环境问题的有效途径。     

Experimental verification of interstage sluice gate design equations

An attempt was carried out earlier to obtain design equations for a new setup of sluice gate to stabilize interstage brine flow in a multiple-stage flash desalination system, based on a two-phase momentum equation. These theoretically developed equations indicated that the sluice gate opening height could be easily obtained, which could maximize and stabilize the interstage brine flow and in turn increase availability and thermal efficiency of desalination plants.In the present work an experimental verification for the above mentioned design equations which governs the stability of interstage brine flow was carried out. A test rig was designed and constructed, which accommodates two adjustable sluice gates. The brine flow in the test section varied from 1.28 to 2.91 kg/s at a 5°C temperature drop per stage. The experimental results obtained indicated good agreement with the theoretical predictions based on earlier work.     

高浓缩倍率低温多效海水淡化药剂阻垢研究

对不同浓缩倍率下盐水中易成垢离子的变化趋势进行了实验研究,对海水淡化厂现用的性能较好的阻垢剂进行了分析,在浓缩倍率为2.5的条件下对不同阻垢剂的阻垢性能进行了研究,并模拟低温多效蒸发环境,进行了水平降膜蒸发实验。结果表明：在40~90℃的条件下,当海水浓缩倍率达到1.5倍左右时钙离子出现损失,随着浓缩倍率提高钙离子损失加大,随着温度的升高损失加剧,钙垢产生的概率变大;在70℃下模拟水平降膜蒸发实验浓缩到2.5倍时,表观结垢量约为134mg/L;阻垢剂的加入可以降低蒸发器上的表观结垢量,在高浓缩倍率下阻垢剂A显示了良好的阻钙离子和阻硫酸根离子结垢的能力;随着阻垢剂加药量的增加,表观结垢量减小,当阻垢剂A的加药量为4.28mg/L,表观结垢量为33mg/L,达到现有海水淡化厂实际运行水平。     

Techno-Economic investigation of an air humidification-dehumidification desalination process

This article presents a humidification-dehumidification (H.D.) process suitable for desalination of sea- and brackish water. The work correlates performance characteristics of the combination of different components in such a loop. Water yield, energy requirement and design data are evaluated as functions of different parameters. The investigation covered water to air mass ratios ranging from 60 to 80, concentration ratios between 2 and 5, at a temperature difference of between 10 and 16 °C, along the liquid for dehumidification. The results showed that 76% of energy consumed in the humidifier is recovered by condensation. Increase of the concentration ratio to 5 can reduce the make-up water and rejected brine by about 58% and 24% respectively. Cost calculations show that the H.D. process has significant potential as an alternative for small capacity desalination plants and permits to operate systems as small as 10 m³/day in output.     

A discussion of “Heat pumps as a source of heat energy for desalination of seawater”

The paper, “Heat pumps as a source of heat energy for desalination of seawater”, was published in Desalination [Vol. 139, 2001]. In the paper, heat pumps using agent R12 or water and vapor were introduced to be used as a source of heat energy for desalination. The cyclic processes of heat pump were illustrated in T-S and P-H thermodynamic diagrams under the conditions ofcondensation temperature at 120°C and an evaporative temperature of 20°C, but there are some questions that need to be discussed. First, thermodynamic diagrams of the transcritical cycle of heat pumps using agent R12 are given. Second, the ratio between mass flows of the water vapor and agent R12 is discussed and the heat balance equations of desalination are given. Third, calculations from a 5 t/d desalination plant are given as an example.     

塔式多效蒸馏海水淡化装置的进料优化

基于全塔负荷均衡的原则，进行了塔式多效蒸馏海水淡化装置的进料优化。结果表明采用优化的三股进料可以使塔内的盐水流量趋于均匀，提高造水比，降低操作的运行费用(电耗和汽耗)，降低预热器的传热面积。而每效的淡化水产量和淡化水累积量几乎不受进料流股数的影响。     

Marginal operation field of existing MSF distillation plants

The capability of existing MSF distillation desalination plants to increase or decrease production by increase or decrease of top brine temperature and brine recirculating flow rate, is technologically limited. The factors which limit the process were analyzed and compared in a practical test carried out on a 4546 m³/d production plant. The brine levels in evaporator stages were calculated and measured to avoid the vapour blowthrough between the stages and to insure the dynamic stability of the plant. There was an increase of 20% in production at 94% of the design brine flow rate, and a top brine temperature 16.6°C greater than the design value before reaching the unsealing limit.     

新一代湿法磷酸生产用泵的开发与应用

针对国产化的湿法磷酸生产用泵不足之处,根据所积累的经验,开发了关键零部件用的JSB合金、JFZ系列卧式耐腐蚀耐磨蚀泵、JLFZ系列立式耐腐蚀耐磨蚀泵和JHZ系列卧式轴流泵,介绍了JSB合金的材料特性和适用范围、这些泵的结构特点和应用。     

Some criteria to minimize the impact of brine dischargeinto the sea

On a uniformly sloping beach, high salinity build-up along the coast associated with brine discharge into the sea can be avoided by building a longer outfall. For an existing seawater desalination plant, extending the outfall will affect the design specification of the plant. Using a two-dimensional advection-diffusion equation, model solutions that can minimize the shoreline salinity levels without building a longer sea outfall are presented.     

海水淡化浓盐水排放与处理技术研究概况

文章分析了不同海水淡化方法浓盐水的主要特征,介绍了国外常用的浓盐水排放和利用技术,包括直接排放法(排入海洋、地表水、污水处理系统等)和浓盐水再利用(灌溉、考虑制盐、提取化工原料)两类。文章分析了上述浓盐水处理技术适用的条件及其优缺点,指出了我国加强相关技术研究和制定相关法规的紧迫性和必要性。     

基于低温蒸馏-喷雾蒸发集成工艺的海水淡化

考察了利用低温蒸馏-喷雾蒸发集成工艺进行海水深度淡化的可行性,使用喷雾蒸发技术深度浓缩蒸馏淡化过程排出的浓盐水,并将余热用于驱动蒸馏过程。考察了蒸馏柱进液量、浓盐水喷雾量、加热空气温度及流速对淡水产量的影响。结果表明,较高的加热空气温度有利于淡水产量的提高,而为获得较高的淡水产量,加热空气流速、浓盐水喷雾量以及蒸馏柱进液量则应控制在一定的范围之内,即10—15 m3/h,0.4—0.6 kg/h和0.8—1 kg/h。对于该集成装置,蒸馏柱淡水产量、总淡水产量及淡水产量与输入淡化系统的蒸汽当量之比(造水比)分别可达5 kg/(h.m2),1 kg/h及1.2,回收率可以达到70%以上。     

多级喷雾闪蒸海水淡化系统性能分析及响应面优化研究

喷雾闪蒸技术因其能耗低、分离效果好、冷却能力高的特点成为解决淡水资源紧缺的有效方法之一。在喷雾辅助低温脱盐技术的基础上,展开系统内部热和质量平衡的热力学计算,研究喷雾闪蒸系统运行级数和顶值盐水温度对闪蒸效果的影响。研究结果表明,更高的顶值盐水温度可以显著提高生产效率,当顶值盐水温度为363 K时,生产率为3.325 kg/s,性能比为0.627。采用响应面法对喷雾闪蒸系统进行优化,确定系统的最佳运行条件以及各响应的模型关系,获得系统淡化的最佳参数：顶值盐水温度343 K,海水进口流量10 kg/s,冷却水进口温度303 K,冷却水进口流量9.5 kg/s。     

核供热堆海水淡化系统的变工况运行特性

针对已经设计完成的某大型多效蒸发海水淡化系统，分析了在分段等面积温差分配方案条件下，系统变工况运行中的某些热工水力学动态响应特性.研究结果给出了海水侧结垢厚度没有稳定之前，系统各效传热面积利用率以及产水潜力的变化情况；分析了原料海水温度因季节变化而降低，影响到系统正常运行时，应该在补给海水流量上采取的措施.还讨论了补给海水流量对核供热堆功率的跟随特性，给出了对应于反应堆不同功率应采用的最佳补给海水流量.本文报道的研究工作可为大型核供热堆多效蒸发海水淡化系统的安全经济运行提供理论依据.     

Energetic aspects of the fouling of MSF desalination plants with and without the use of on load ball cleaning system

Multi-stage flash (MSF) desalination plants are designed with specific permissible fouling factors. When these conditions are met, the performance is said to “meet design”.With single- purpose desalinators, fouling of the brine heater can be compensated for by increasing the steam pressure without substantial increase of heat consumption and within the limits of the boiler pressure. With dual-purpose desalinators, the brine heater pressure will influence the efficiency of the turbine process.Fouling of the heat recovery section increases the heat consumption of the MSF process. The distillate production can be maintained within the limits of the boiler.Typical “design fouling factors” have been compiled from literature.The influence of fouling factor on specific heat consumption has been calculated for typical MSF design conceptions, as well as the increase of water costs per m³ with different fuel prices.The costs of various scale prevention methods have been evaluated. The effectiveness of such countermeasures can be quantified by plant experience.This analysis of cost/return gives a basis for a correct economic comparison.