制冷系统热氨融霜事故分析与对策

Analysis and Countermeasure of the Ammonia Hot Gas Defrosting Accidents in Refrigeration System

热氨融霜作为冷库氨制冷系统蒸发器的高效融霜方式之一,被广泛采用。但是由于其在设计、施工、操作运行等环节存在的一些问题,往往在热氨融霜时出现安全事故,甚至是重大安全事故。本文在分析热氨融霜与制冷工况特性及运行状况的基础上,分析了热氨融霜过程中,管道受力情况并指出现有制冷系统中管道受力的薄弱位置。结合常规热氨融霜管道的母材及所采用焊接材料、焊接形式,提出避免热氨融霜事故发生的设计、安装、操作运行的防控措施及发展方向。

Hot ammonia defrosting is widely used as one of the efficient defrosting methods for the evaporator of cold storage ammonia refrigeration system. However, due to some problems that may happen during the process of design, construction, and operation, there are often safety accidents, even major safety accidents, during the process of hot ammonia defrosting. Based on the analysis of the characteristics of hot ammonia defrosting, refrigeration and operating conditions, this paper investigated the stress of the pipes, and pointed out the weak position in the stress of the pipes in current refrigeration system during the process of hot ammonia defrosting. In combination with the parent metal of pipes during the process of conventional hot ammonia defrosting, welding materials, and welding forms, this essay put forward development directions and protective measures to avoid the accidents occurred in the design, installation, and operation during the process of hot ammonia defrosting.