氨制冷压力容器定期检验相关问题分析

随着大量制冷装置的建成和使用,氨制冷企业安全问题日益突出,定期检验作为保证在役氨制冷压力容器安全使用的一个重要环节,目前仍存检验依据不清、检验项目不明、检验针对性不足等问题.文中对氨制冷压力容器定期检验现状进行了介绍,对氨制冷压力容器损伤机理进行了分析和讨论,从损伤模式判别的角度提出了相应的检验策略,给相关人员提供一些...     

HAZOP和LOPA方法在食品企业氨制冷系统中的应用

为评估食品企业氨制冷系统所处的风险状态,文章在HAZOP方法和LOPA方法理论研究的基础上,将其组合应用于食品企业氨制冷系统的风险评估中,以提前识别可能导致事故的原因和后果,确定现有防控措施是否足够、有效,并将风险控制在可接受水平。通过对氨制冷系统中低压循环桶液位过高场景的实例分析,得出该场景下的剩余风险基本在企业可接受范围内,不需要增加独立安全仪表系统的结论,为食品企业安全管理决策提供了科学依据。     

一起氨制冷系统管道断裂事故的原因分析

制冷系统的库房回气管道发生了断裂失效,断裂位置在环焊缝中心且断口平整,焊缝存在未焊透缺陷。管道采用管束整体发泡保温,增加了管道的刚性,不利于管道的位移补偿。通过对管道材质进行分析,化学成分和力学性能符合设计要求。对管道受力状态进行分析并进行应力计算,结果表明,管道焊接接头未焊透,削弱了焊接接头的承载能力。管道在"冷缩"时不能补偿而产生较大的拉应力,导致在管道强度薄弱的焊接接头处发生断裂失效。     

Biomass Based Sorption Cooling Systems for Cold Storage Applications

Controlled atmospheric storage is a widely popular technique for storage of fruits and vegetables. In this paper, the experimental studies on biomass powered absorption systems for cold storage applications using ammonia water as a working fluid pair is presented. The heat input to the absorption system is supplied by a producer gas obtained from a downdraft gasifier, using firewood as fuel. The system is designed and fabricated to store about 15 MT of fruits and vegetables, having a cooling capacity of 3 TR. The effect of sink temperature, solution flow rate, cooling water flow rate and biomass consumption on the performance of the system has been analyzed. It is found that the real co-efficient of performance of the system is around 0.35 - 0.2, considering the source-site factor for auxiliary power consumption. The operating Cost/h for the biomass based cold storage system is lower than the presently available conventional compression based units.     

氨氮水样的稳定性试验

对采集于聚乙烯塑料瓶内的氨氮地表水样，应立即加入盐酸，使pH值≤2进行现场固定，分别于2～5℃恒温冷藏保存，与20．28℃室温保存，每隔48h检测，连续检测一个月。检测结果统计表明，两种保存方法的测试结果基本一致，氨氮水样在一个月内的检测值基本恒定，水样表现稳定。     

行波管性能测试用试验箱的结构特点及其设计

介绍了一种专门用于行波管性能测试的试验箱的设计过程。在对试验箱结构特点进行分析的基础上,通过结构设计、制冷系统设计和控制系统设计,尤其在风道结构布局方面的创新设计,成功研制了该型试验箱,并在生产过程中得到了实际应用。     

氨制冷系统的压力管道安全

氨制冷系统压力管道在特定的环境和特定的工作参数下运行,压力管道的安全性能与设计、安装、检验试验和使用密切相关。关注氨制冷系统压力管道在设计、安装、检验试验和使用方面常出现的问题,有针对性的整改,对预防和提高氨制冷系统压力管道的安全性具有重要意义。     

空气涡轮制冷低温粉碎法回收废弃橡胶

利用带回冷循环的空气涡轮制冷系统，在低温条件下，将废旧橡胶进行冷冻、粉碎、制成６０目以上的精细胶粉。此法的冷冻能耗成本仅为国际上通用的液氮法的１／１０，整具工艺过程不产生二次污染，为废旧橡胶的综合利用提供了一条新途径。     

Experimental study of the stack geometric parameters effect on the resonance frequency of a standing wave thermoacoustic refrigerator

Thermoacoustic refrigeration is an emerging technology that makes use of acoustic power to pump heat. The resonance frequency is important for the performance of thermoacoustic refrigerators, as it affects the temperature difference across the stack. This paper aims to optimize the performance of thermoacoustic refrigerators by experimentally investigating the effect of the stack geometric parameters (i.e. stack position, stack length, and the stack size) on the resonance frequency of a standing wave loudspeaker driven thermoacoustic refrigerator. Celcor Ceramic stacks of normalized positions of 0.764, 1.05, 1.43, and 1.72, normalized lengths of 0.076, 0.114, 0.153, and 0.191, and two porosities of 0.8 and 0.85 are used. The clarification of the relationship between the stack geometric parameters and the resonance frequency of the thermoacoustic refrigerator is presented. Moreover, the coefficient of performance of the thermoacoustic refrigerator is observed to increase at the resonance frequency of each stack configuration.     

氨制冷系统压力管道安装及实验的要点

近年来,液氨管道事故的不断发生,引起了人们对氨制冷管道系统工程的高度重视.首先介绍了氨的性质,然后介绍了氨制冷管道安装及实验应该注意的一些要点,希望能对氨制冷工程的管道安装质量起到一些作用.