不同参数对含盐污水在蒸发管中流动特性影响的数值模拟分析

蒸发处理是炼化企业产生的含盐污水处理的方法之一,但是蒸发过程存在着因流动条件差异而导致传热效果不佳的问题。以降膜蒸发含盐污水为研究对象,通过数值模拟的方法分析不同参数对蒸发管传热传质效果的影响。结果表明,液体入口速度不同对蒸发管加热效果的影响是复杂的,入口速度适当增大导致轴向速度增大,虽然液体加热时间会变短,但加热效果更好;增大布膜间隙对近壁面处温度分布有积极作用,但在距管中心13.5～18.0mm范围内气相湍流强度略低,布膜间隙为1.25 mm时的温降相较于1.0 mm和1.5 mm间隙时的温降大;含盐污水盐度增大对蒸发管传热传质效果不利,特别是在近壁面处温降增大,内部湍流强度在沿径向方向距管中心0～19 mm范围内增大,近壁面处距管壁4 mm范围内速度增大。     

Optimization of the Liquid Distributor in a Falling Film Evaporator by Means of Air‐Water Experiments

Air‐water experiments (cold‐flow experiments) were performed for the liquid distributor of an industrial falling film evaporator (FFE). The feed to the FFE is superheated and a flash evaporation occurs in the head of the FFE. The aim of the experiments was to investigate the vapor‐liquid flow in the head and the resulting liquid distribution to the evaporator tubes. Several different designs of the distributor were investigated and explanations for the performance losses of the real evaporator over time were found. Several measures were finally concluded and also implemented for the real FFE.     

Droplet Entrainment Analysis in a Flash Evaporator with an Image-Based Measurement Technique

Local droplet sizes and volumes of entrained liquid are captured with an image-based measurement technique for comparison with a conventional, integral method for entrainment analysis. Experiments in a forced circulation flash evaporation were performed for different operating conditions and with two different chemical systems. Droplet size and frequency rise with an increase in thermal energy input. The local readings confirm the trends found by the integral measurement method. The modification of the image-based probe enables the detection of small (≈ 10 µm) and at the same time fast droplets under challenging operating conditions, such as vacuum and superheated feed similar to industrial process conditions.     

蒸发器支座结构分析

通过多个模型的建模及有限元分析支座的受力情况，总结出蒸发器的支座形式，为大型容器支座设计提供相应的参考。     

高效节能冰激凌机直冷式冷冻缸蒸发器的设计

这里介绍了一种高效节能的冰激凌机螺旋翅片直冷式圆形冷冻缸蒸发器，并指出其实现的关键技术。     

立式敞开式制冷陈列柜主要结构参数的合理选择

在理论和实验研究立式敞开式制冷陈列柜工作特性的基础上，讨论了合理选择陈列柜送风速度、蒸发器结构和融霜周期等结构参数的途径。     

翅片管式蒸发器的计算机辅助设计

就计算机辅助设计在制冷系统部件设计表面作了一定的探索,使产品设计更快捷更优化。     

空气源热泵结霜机理及除霜/抑霜技术研究进展

结霜导致蒸发器的热阻增加,传热系数降低,系统COP减小,制约了空气源热泵的推广应用。本文在表面结霜机理研究现状的基础上,总结了影响结霜的各种因素相应除霜/抑霜技术,综述了逆循环、热气旁通和电加热三种常用除霜方法的研究进展,概括了改变空气参数、表面温度和换热器结构的抑霜效果,以及表面改性抑霜技术的研究现状。指出霜导热系数模型的局限性及除霜/抑霜技术存在的问题,提出今后应结合多种措施着重探索对水蒸气凝结、冷凝水冻结、霜层回融和塌陷等阶段均有较强抑制作用的抑霜技术。     

CQS.FFH-2型水面遥测蒸发器的应用

介绍了CQS.FFH-2型水面遥测蒸发器的系统组成及工作原理,分析了其在百色水文站的应用情况,探讨了水面蒸发测验设备的遥测自动化改革方案。     

低成本连续化的氯化锌制造工艺

以锌灰和废盐酸为原料，用连续反应装置生产氯化锌，不仅成本低，而且无气体逸出；用蒸发器代替敞开式的石墨板蒸发器，不仅节省能量，而且无蒸汽四逸；采用可回收滤渣的工艺，既回收了有利用价值的铅、铜、三氧化二铁等物质，又解决了重金属的污染问题。经厂家的生产实践证明，这种氯化锌制造工艺既避免了污染，又能获得较好的经济效益。