液氨制冷机房氨气微泄漏的排风优化研究

发布时间：2018-01-26 22:14

本文关键词： 液氨制冷机房微泄漏数值模拟抽风机　出处：《中国地质大学(北京)》2017年硕士论文　论文类型：学位论文

【摘要】：在冷冻冷藏行业大多数的制冷企业的制冷系统,目前采用的都是氨制冷。但在储存和使用过程中氨易发生泄露,引发中毒甚至爆炸事故。经过排查发现,兰陵县涉氨制冷企业中有近五分之一的制冷机房存在不同程度的氨气微泄漏情况,这对制冷工人的职业健康构成威胁,泄露的氨气一旦积聚可能引发爆炸,存在较大的安全隐患。良好的通风能够缓解泄漏后氨扩散对整个机房的影响,有效的通风可以降低泄漏的氨气浓度,既保护了工人的职业健康,也能避免泄露的氨气积聚,引发爆炸。本文针对典型液氨制冷机房,采用CFD数值模拟技术,对其自然通风和机械抽风情况进行数值模拟,对不同排风方式下,厂房内部多个截面的氨气浓度进行分析。在排查的多个机房中本文选择一个较典型的案例进行排风方案的改进。本文从排风口面积、排风方式、抽风机选型这三个方面提出三个改进设计方案。第一个改进方案是将制冷机房的门和所有窗户打开,利用空气对流的方法加速氨气扩散,降低氨气浓度,得出厂房不同截面氨气的浓度云图。第二个改进方案是在保持制冷机房的门和所有窗户打开的情况下,在机房右侧排风口设置一台规格为50cm*50cm*40cm,抽风量为15000m3/h,功率0.4kw的抽风机,模拟后得出厂房内不同截面的氨气浓度云图。第三个改进方案是在保持制冷机房的门和所有窗户打开的情况下,在机房右侧排风口设置一台规格为90cm*90cm*40cm,功率0.7kw,抽风量为30000m3/h的抽风机,得出厂房不同截面氨气的浓度云图。分析的结果对厂房排风方式和抽风机的选择提供了理论依据,对实现排风降低制冷机房氨气浓度,在提高液氨制冷企业的生产安全性方面,有一定的理论指导和现实意义。
[Abstract]:In the refrigeration system of most refrigeration enterprises in the refrigeration and refrigeration industry, ammonia refrigeration is used at present. However, ammonia is easy to leak in the process of storage and use, which leads to poisoning and even explosion accident. Nearly 1/5 of the refrigeration rooms in Lanling County have different degrees of micro-leakage of ammonia gas, which poses a threat to the occupational health of refrigeration workers. Once the leaked ammonia gas accumulates, it may trigger an explosion. Good ventilation can alleviate the effect of ammonia diffusion on the whole engine room after leakage, and effective ventilation can reduce the concentration of ammonia gas leakage, which can protect the occupational health of workers. It can also avoid the accumulation of leaking ammonia gas and cause explosion. In this paper, the natural ventilation and mechanical ventilation are numerically simulated by using CFD numerical simulation technology for typical liquid ammonia refrigeration machine room. The ammonia concentration of several sections in the factory building is analyzed under different exhaust air modes. A more typical case is selected to improve the ventilation scheme in many machine rooms investigated in this paper. The area of exhaust air outlet is analyzed in this paper. The first one is to open the door and all the windows of the refrigeration room and to speed up the ammonia diffusion by air convection. Reduce ammonia concentration, get different sections of ammonia concentration cloud diagram. The second improvement is to keep the refrigerating room doors and all windows open. At the outlet on the right side of the engine room, there is a draft machine with a specification of 50 cm / m ~ (50) cm ~ (-1) and a power of 0. 4 kW with a pumping capacity of 15 000 m ~ 3 / h and a power of 0. 4 kw. The third improvement scheme is to keep the door and all the windows of the refrigeration room open. At the outlet on the right side of the engine room, there is a draft machine with a specification of 90 cm, 90 cm, 40 cm, 0.7 kwk of power, and an output of 30000m3 / h. The results of the analysis provide a theoretical basis for the selection of the exhaust air mode and the extractor of the workshop and reduce the ammonia concentration in the refrigerating machine room by the exhaust air. In improving the production safety of liquid ammonia refrigeration enterprises, there are certain theoretical guidance and practical significance.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU834

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