乙二醇不锈钢蒸发器开裂原因分析

采用金相分析、断口微观分析以及腐蚀产物能谱分析等方法，对某石化公司乙二醇不锈钢蒸发器开裂原因进行了分析和研究。结果表明，由于材料在焊接过程中，焊接热影响区的组织受到敏化，铬的碳化物沿晶界呈网状析出，造成该区域贫铬，从而在应力与腐蚀介质的共同作用下，导致设备发生了晶问应力腐蚀开裂。     

分离式热管蒸发段工质流动不稳定性的试验研究

在试验台架上进行了可视化试验和模型试验,对分离式热管蒸发段工质流动的规律和工质流动的不稳定性进行了试验研究.可视化试验结果表明,对于小倾角布置的蒸发段,随着热流密度的增加,流型依次是泡状流、弹状流、波动泡沫状流;分离式热管蒸发段工质流动出现了流型转化型和密度波型两种不稳定性流动.通过模型试验确定了压力、质量流速、入口过冷度、热流密度、出口节流阻力等因素对不稳定性的影响,得出了流型转化型和密度波型不稳定性的界限.利用一维均相模型给出了计算不稳定性起始条件的无因次方程.     

TALOSCALE松垢剂的应用研究

本文通过实验研究了TALOSCALE的防垢机理，并进行了工厂应用研究，研究结果表明，TALOSCALE具有很好的防垢、松垢及除垢效果。提高了蒸发罐的蒸发强度，防垢率高达82．80％，积垢变松软。易于清除，并可代替酸或碱进行煮罐，不损伤加热管表面，使用安全，积垢变薄，疏松易除。     

制氮设备预冷机组蒸发器堵塞的原因分析与处理

介绍1500m~3/h制氮设备空压机排气压力与空气进精馏塔压力的压差增大的故障现象,分析后认为预冷机组蒸发器空气通道堵塞是故障发生的原因,引入氮气对蒸发器空气通道进行反吹后消除了故障。对预冷机组的流程进行了改造,以实现在不停运制氮设备的情况下处理蒸发器空气通道堵塞的目标。     

间冷式冰箱蒸发器结霜模拟

针对间冷式冰箱蒸发器的结霜工况进行了模拟。在改进现有的计算霜表面水蒸气过饱和度公式的基础上，建立了适用于间冷式冰箱蒸发器的霜层生长模型，并模拟出结霜过程中的结霜量，空气侧压降，霜的密度和厚度随时间的变化。通过与实验数据的比较，结霜量的误差在10％以内，空气侧压降在25％以内，该模型能够有效的模拟间冷式冰箱蒸发器的结霜过程。     

Hot gas defrost model development and validation

This paper describes the development, validation, and application of a transient model for predicting the heat and mass transfer effects associated with an industrial air-cooling evaporator during a hot gas defrost cycle. The inputs to the model include the space dry bulb temperature, space humidity, coil geometry, frost thickness, frost density, and hot gas inlet temperature. The model predicts the time required for a complete frost melt as well as the sensible and latent loads transferred back to the conditioned space during the defrost period. The model is validated by comparing predicted results to actual defrost cycle field measurements and to results presented in previously published studies.A unique contribution of the present model is its ability to estimate parasitic space loads generated during a defrost cycle. The parasitic energy associated with the defrost process includes thermal convection, moisture re-evaporation, and extraction of the stored energy in the coil mass following a defrost cycle. Each of these factors contribute to the parasitic load on compressors connected to the defrost return. The results from the model provide quantitative information on evaporator operation during a defrost cycle which forms the basis to improve the energy efficiency of the defrost process.     

On the selection of fin profiles for OTEC plate-fin evaporators

This paper considers the plate-fin heat exchanger for an OTEC power plant on account of its compactness. Ammonia is selected as the working fluid for a plant of 1 MW gross output. Choice of seawater side velocity is made on the basis of pressure drop and biofouling. Fourteen different fin profiles are considered in order to choose a suitable configuration. The selection of the plate-fin heat exchanger depends on minimum exchanger volume, minimum pumping power requirement and low ammonia side pressure drop.     

Optimum control of the gas overheat in the evaporator of a vapour compression refrigeration system when the refrigerant is polluted

Results concerning the response of a refrigeration system simulation software to an increase in the amount of oil flowing with the refrigerant are presented. It is shown that there are optima of the apparent overheat value, for which either the exchanged power or the refrigeration coefficient of performance (COP) is maximised: consequently, it is not possible to optimise both the refrigeration COP and the evaporator power. However, in most of the cases (i.e. contents of circulating lubricant), the optimal values of the apparent overheat are below the values that the expansion valves usually impose.     

空分设备低温残液蒸发设备的选用

文章介绍和分析了当前空分设备中低温残液蒸发设备的类型及特性,并对各类残液蒸发设备进行了综合分析和比较,提出了低温残液蒸发设备设计和使用时应注意的问题。     

汽车空调蒸发器分布参数动态模型及数值仿真

蒸发器是汽车空调系统的主要部件,建立蒸发器性能仿真模型是开发汽车空调仿真系统的一项重要工作。该文基于过程物理机理,建立了汽车空调系统蒸发器分布参数动态数学模型,并给出了具体的数值仿真算法;借助该文的仿真模型,可以对制冷系统蒸发器的动／静态特性进行较为全面的仿真分析,预测不同运行工况下蒸发器热力参数的瞬态分布状况,同时还可以十分方便地确定出制冷剂单／双相区域分界点的瞬态位置;文中通过一个仿真算例说明了所建立的仿真模型可用性。