液冷机载电子设备凝露分析

为了深入研究液冷机载电子设备的凝露问题,从凝露定义、形成条件入手,分析了机载电子设备在典型环境试验条件产生凝露的可能性。对液冷模块、高低温箱中产生凝露的条件进行了详细分析,为有针对性地开展防凝露或排水设计提供参考。     

凝露造成高低压开关柜的故障分析

随着城市配电网应用的不断增加,凝露问题也随之凸显。叙述了凝露对配电设备造成的4种常见危害:凝露造成绝缘故障及相间短路故障;气象凝露造成机构锈蚀故障;环境湿度凝露造成击穿故障。并通过总结实际工作经验,针对凝露造成的故障进行分析,找到处理的方法和措施,效果显著。     

格栅式防凝露预制舱设计与研究

为了减少预制舱产品的凝露问题，分析了预制舱凝露问题产生的原因，针对具体原因对预制舱顶盖结构进行针对性优化，设计了一款格栅式防凝露预制舱结构。通过理论公式的推算，得到了格栅式防凝露预制舱顶盖保温层厚度与外界环境温度和选用材料种类的关系，可以指导保温材料种类和厚度的选择。依据上述设计方案，设计并加工了试验样机，对样机进行交变湿热试验。结果表明，格栅式防凝露预制舱能够有效避免凝露的产生，同时也验证了顶盖保温层厚度计算方法的科学性。     

户外型控制柜凝露预防

凝露作为自然界当中极为普遍的自然现象,其对植物生长具有非常重要的作用,但是其对于电力系统而言,一旦控制柜当中出现大量凝露,便会导致电力设施时长出现运行故障,这对我国输配电稳定性造成了极大的影响。采取有效的防凝露措施能够显著降低凝露现象的出现,同时也能够降低凝露造成的事故。本文对电力系统当中设备存在凝露所能带来的影响入手分析,对控制柜出现凝露的主要位置进行分析,提出控制柜预防凝露出现的措施,以期对相关研究者有所借鉴作用。     

核电站光电感烟探测器的防凝露装置设计

以核电站火灾报警系统中的光电感烟探测器为研究对象,结合其工作原理,分析了潮湿对火灾探测误报影响,提出了一种光电感烟探测器防凝露装置的设计方法。从设计的合理性和安全性等方面进行论证,并通过试验验证防凝露装置的性能。试验结果表明,该防凝露装置可以解决由潮湿引起的误报问题。     

高压开关柜新型防凝露系统的研究与应用

针对高压开关柜散热与防凝露装置控制系统故障导致的柜内温湿度升高引起高压开关柜爆燃、放电的问题,本装置采用智能化采集装置。首先,实时采集电气数据、设备运行参数和柜内环境参数,并将其实时数据上传到云数据库中,利用模糊控制技术,由变电站运行维护和维护人员利用计算机或手机进行高压开关柜及其散热、防凝露装置的远程监控和智能控制;其次,介绍了一种新型的高压开关柜防凝露系统,从凝露原理、开关柜凝露原因及现有防凝露方法的缺陷等方面进行了探讨,从而有效解决高压开关柜普遍存在的空气湿度大、易凝露等难以治理的问题;最后,经过现场试验及使用,该智能控制装置具有良好的工作稳定性,能够准确地完成对高压开关柜进行精确的散热和除湿,保证其工作的安全性和稳定性。     

变电站端子箱防潮防凝露策略及集中控制技术研究

在电力系统中,端子箱作为重要的连接和分配点,其内部环境的稳定性对设备的性能和可靠性至关重要。本文通过对端子箱的潮湿和凝露原因进行分析,深入探讨了防潮防凝露措施的新技术,并研究了集中控制技术如实时监测、远程访问、警报系统和自动控制在端子箱防潮和防凝露中的作用。强调了通过合理的策略和技术应用,能够降低潮湿问题的风险,提高电力系统的可靠性,并降低维护成本。     

空调器防凝露优化控制技术研究

分析空调器凝露不合格现象产生的机理,通过针对现有空调器防凝露控制技术的缺点和不足,从而提出了防凝露优化控制技术方法研究。实验证明该方法能准确判断进入防凝露模式的时间点,并通过导风条定位角度和设定风速档位来调整压缩机工作频率的方法来实现防凝露目的,从而达到理想的防凝露效果。     

EPR堆型核电站管道保冷效果分析及改进建议

根据台山一期1号机组系统运行情况,部分保冷管线存在凝露的现象,保冷效果不佳。通过对施工逻辑、保冷厚度、保冷范围等方面进行分析并提出改进建议,解决了管道凝露的问题,取得了良好的效果,具有良好的推广价值和经济效益。     

防水透气阀对设备内部凝露影响分析

防水透气阀作为平衡设备内外气压的重要器件,在诸多研究分析其适用性时,往往看重其气体交换率、防水等常规性能,而忽略了其是否会对设备内部的凝露情况造成影响。文章通过理论分析及实验证明了在有无防水透气阀的情况下,设备内部的凝露情况。根据试验结果,未加装防水透气阀的设备在外部温湿度变化情况下,内部会形成凝露,且蒸发速度较慢;在加装了防水透气阀的情况下,设备内部湿度随外部湿度变化速率加快,同样形成凝露,并随着外部湿度降低而迅速蒸发。可见加装防水透气阀,并不会使凝露情况变差,反而可以迅速蒸发凝露,从而减少设备内部凝露积水风险,提升运行的可靠性。     

空调器无滴水调湿技术研究开发

家用空调器冷凝水的滴流及造成室内空气干燥、混浊等问题依然是空调业面临的问题,文章介绍了无滴水可调节湿度技术的原理及该技术装置的主要硬件构成.研究结果表明,该装置能较好的收集空调冷凝水、对空调室内进行雾化加湿及促进空调冷凝器的热交换,可以解决空调器冷凝水的任意滴流及改善室内空气质量.     

家用空调器无滴水可调湿技术研究

介绍了无滴水可调节湿度技术的原理及主要硬件构成，以及控制装置的核心软件模块。研究结果表明：该装置能较好的收集空调冷凝水，对空调室内进行雾化加湿及促进空调冷凝器的热交换，可以解决空调器冷凝水的任意滴流及改善室内空气质量。     

毛细管平面辐射空调系统的优化控制

针对传统空调系统中主要通过对流换热的方式来消除室内的热湿负荷造成能源品味上的浪费问题,将毛细管辐射换热技术应用于空调系统中,开展了由毛细管承担室内显热负荷而由新风系统承担全部的室内潜热负荷空调处理方案的分析,建立了空调房间温度与湿度之间相互独立的控制方法,并提出了采用冷冻水变流量优化控制法解决毛细管换热中的结露问题.在新风系统运行时,毛细管辐射供冷系统停止供水;新风系统除湿结束后,毛细管辐射供冷系统开始供水,在此基础上对毛细管辐射供冷系统采用间歇性流量控制方案进行了评价.研究结果表明,该控制方案不仅简单易行,而且节约能源.     

辐射空调过冷度与结露延迟时间动态变化特性研究

针对辐射空调在运行时出现结露现象的问题,为提升辐射空调系统的供冷能力,延后防结露控制启动时间,采用试验研究的方法,对辐射板表面结露区域进行分析,并在板表面最易结露区域进行结露过程试验,确定结露发生时刻的状态点,在此基础上进一步探讨过冷度与结露延迟时间随影响因子变化的动态变化特性及二者关系.研究结果表明:结露区域的范围受...     

Film-wise and drop-wise condensation of steam on short inclined plates

Film-wise and drop-wise condensation experiments were carried out at atmospheric pressure varying the condensing plates, their inclinations and orientations (upward or downward facing), and the air concentrations. As expected, dropwise condensation showed much higher heat transfer rates than corresponding film-wise condensation in the pure steam cases. However, with the presence of air, both modes of condensation showed similar heat transfer rates due to the high thermal resistance of the air-rich layer. Both modes of condensation showed systematic decreases in heat transfer as the angle of the plate to the horizontal decreased and as the concentration of air increased. A noteworthy observation made during the tests on the plate orientation showed that condensation heat transfer rates on the upward facing plate were slightly higher than those beneath the downward facing plate in the pure steam cases but that the trends were reversed in the steam and air mixture cases.     

基于ANSYS的石膏墙板湿热养护过程的仿真研究

通过采用ANSYS内FLOTRAN／CFD的功能，对石膏墙板养护房内空气流动和换热问题进行了仿真研究。建立了养护房内以空气为加热流体的二维ANSYS模型，模拟了养护房内的温度场和速度场，为分析石膏墙板养护设备运行情况奠定了基础。     

A study on method of reducing condensation for total heat exchanger under humid conditions

An experimental study was performed to reduce the condensation under very humid conditions for a total heat exchanger. The hydrochromic ink was used to detect the condensation within the total heat exchanger. Condensation in a total heat exchanger can be reduced by decreasing the flow rate of the supply air. The other method of decreasing the flow rate of the exhaust air can also be used to reduce condensation. However the flow rate of the exhaust air has to be less than half of the supply air flow rate for the tested total heat exchanger.     

Comprehensive Parameter for Analyzing Condensation in Pneumatic System

The condensation in pneumatic system is a complex physical phenomenon dependant upon status variation and phase transitions,which are related to the parameters of the compressed air,atmospheric conditions and the dimensions of the pneumatic components.Up to now,general research method for this problem is to calculate the status variation and movement quantity by numerical simulation and experiment directly.The comprehensive parameters composed of several different effect factors are rarely used to study the condensation.The composed components and the working conditions of each cylinder are different,a large number of experiments and complex calculations are necessary to determine the condensation.Additionally,the transferability of the determined results is poor.In this paper,the charging and discharging systems of serials cylinder with different structure parameters are studied.The condensation of the systems is observed and the effects of the structure parameters on condensation are analyzed.The changing trends of relative humidity,natural frequency and average speed against the structural parameters of the components during discharge of the pneumatic systems are analyzed.Three comprehensive parameters used to analyze and determine condensation composed by structure parameters of components are proposed,namely,the ratio of the effective area of the discharge tube and the container volume,the square root of the effective area of the discharge tube divided by the product of the container volume and the length of the discharge tube,and the discharge dimensionless tube-volume.The experimental results show that these comprehensive parameters can be used to quantitatively determine whether internal,external or zero condensation occurs in a pneumatic system,and can be also used to quantitatively analyze the experimental data of condensation in pneumatic systems directly.At the same time,the effect factors are too much and the effect relationships are very complex,which causes that the conclusions can't be put forward by using single effect factor in experimental data processing individually.The three obtained comprehensive parameters can be used to resolve the above problem.The proposed parameters can also resolve the problem of poor transferability in determining the state of condensation in pneumatic systems,and provide a novel method for the further study of condensation theory.     

变风量情况下房间压差控制方法

针对某洁净厂房由于工艺排风量变化所引起的房间压差混乱问题,分析了压差变化的原因,并讨论了合理的漏风量计算方法,提出了变风量情况下房间的压差控制方法。另外,重点讨论了变风量控制阀的应用、控制方法并对常用的两种变风量阀文丘里控制阀和VAV蝶阀的性能进行了比较。     

Time-dependent characteristics of the nonequilibrium condensation in subsonic flows

High-speed moist air or steam flow has long been of important subject in engineering and industrial applications. Of many complicated gas dynamics problems involved in moist air flows, the most challenging task is to understand the nonequilibrium condensation phenomenon when the moist air rapidly expands through a flow device. Many theoretical and experimental studies using supersonic wind tunnels have devoted to the understanding of the nonequilibrium condensation flow physics so far. However, the nonequilibrium condensation can be also generated in the subsonic flows induced by the unsteady expansion waves in shock tube. The major flow physics of the nonequilibrium condensation in this application may be different from those obtained in the supersonic wind tunnels. In the current study, the nonequilibrium condensation phenomenon caused by the unsteady expansion waves in a shock tube is analyzed by using the two-dimensional, unsteady, Navier-Stokes equations, which are fully coupled with a droplet growth equation. The third-order TVD MUSCL scheme is applied to solve the governing equation systems. The computational results are compared with the previous experimental data. The time-dependent behavior of nonequilibrium condensation of moist air in shock tube is investigated in details. The results show that the major characteristics of the nonequilibrium condensation phenomenon in shock tube are very different from those in the supersonic wind tunnels.