最近因为业务需要看了氮气发生器系统的控制面板。因此，特意对惰气系统（发生器）研究了一下。

1、适用性

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SOLAS chapter II-2/reg4

5.5.1.1 For tankers of 20,000 tonnes deadweight and upwards constructed on or after 1 July 2002 but before 1 January 2016, the protection of the cargo tanks shall be achieved by a fixed inert gas system in accordance with the requirements of the Fire Safety Systems Code, as adopted by resolution MSC.98(73), except that the Administration may accept other equivalent systems or arrangements, as described in paragraph 5.5.4.

5.5.1.2 For tankers of 8,000 tonnes deadweight and upwards constructed on or after 1 January 2016 when carrying cargoes described in regulation 1.6.1 or 1.6.2, the protection of the cargo tanks shall be achieved by a fixed inert gas system in accordance with the requirements of the Fire Safety Systems Code, except that the Administration may accept other equivalent systems or arrangements, as described in paragraph 5.5.4.

5.5.1.3 Tankers operating with a cargo tank cleaning procedure using crude oil washing shall be fitted with an inert gas system complying with the Fire Safety Systems Code and with fixed tank washing machines. However, inert gas systems fitted on tankers constructed on or after 1 July 2002 but before 1 January 2016 shall comply with the Fire Safety Systems Code, as adopted by resolution MSC.98(73).

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解析：1）2002年7月1日到2016年7月1日的所有20000总吨以上的液货船（Tanker）

但是要注意某些特殊情况

5.5.2.1 The requirements for inert gas systems contained in the Fire Safety Systems Code need not be applied to chemical tankers constructed before 1 January 2016, including those constructed before 1 July 2012, and all gas carriers:

2）2016年7月1日及以后所有的8000总吨以上的液货船，并且其载运一下货品

A)Requirements for tankers in this chapter shall apply to tankers carrying crude oil or petroleum products having a flashpoint not exceeding 60°C (closed cup test), as determined by an approved flashpoint apparatus, and a Reid vapour pressure which is below the atmospheric pressure or other liquid products having a similar fire hazard.

B) Where liquid cargoes other than those referred to in paragraph 6.1 or liquefied gases which introduce additional fire hazards are intended to be carried, additional safety measures shall be required, having due regard to the provisions of the International Bulk Chemical Code, as defined in regulation VII/8.1, the Bulk Chemical Code, the International Gas Carrier Code, as defined in regulation VII/11.1, and the Gas Carrier Code, as appropriate.

因此，我们一般见到的加油船，从2016年7月1日及以后，无论多少吨位，都不需要有惰气系统。而对于原油船，如果设置固定式原油洗舱机，无论多少吨位，都需要设置惰性系统。

2、需要布置的处所

1）Tankers required to be fitted with inert gas systems shall comply with the following provisions:

2）5.5.3.1 The inert gas system shall be capable of inerting, purging and gas-freeing empty tanks and maintaining the atmosphere in cargo tanks with the required oxygen content.

解析：货油舱以及和货油舱相邻的处所；注意：sloptank也是货油舱。但是要注意其闪点是否小于等于60度。

3、惰性气体系统种类

Inert gas system includes inert gas systems using flue gas, inert gas generators, and nitrogen generators and means the inert gas plant and inert gas distribution together with means for preventing backflow of cargo gases to machinery spaces, fixed and portable measuring instruments and control devices

目前有三类。即：主锅炉和/或副锅炉的烟道气、惰性气体发生器、氮气发生器。

本文重点介绍氮气发生器。因为其制造的氮气比较纯，适用于所有的船。不像惰性气体，其一般适用于对于气体质量要求不高的货品，比如原油。

同时：烟道气和惰气气体发生器，其本质是一样的，都是燃烧空气。然后……

4、氮气发生器

1）种类

目前我见过的有2种，重点介绍PSA（Pressure Swing Adsorption）

A膜法氮气发生器通过特殊分离膜材料，如高分子膜，将氧气和其他杂质从空气中分离出来。这个过程依赖于气体分子在不同物质表面的渗透速率差异，即小分子和极性较强的分子的通过速度快于大分子和极性较弱的分子的通过速度。

B变压吸附空分制氮(简称P.S.A制氮) 是一种先进的气体分离技术，以优质进口碳分子筛（CMS）为吸附剂，采用常温下变压吸附原理（PSA）分离空气制取高纯度的氮气。

2)看网络介绍

吸附式氮气发生器的工作原理,科技,工业机械,好看视频 (baidu.com)

3)主要设备

空压机、干燥器、滤器、空气贮存罐(也叫 空气缓存罐)、吸附塔、氮气贮存罐(也叫 氮气缓存罐)、阀组、氧气分析仪。下图一张Minic图，就是展示了所有。

5、为啥设置这些设备，是满足什么要求？

1）空压机

2.4.1.1 The system shall be provided with one or more compressors to generate enough positive pressure to be capable of delivering the total volume of gas required by paragraph 2.2.1.2.

注意：可以采用经济模式。不一定需要3台同时工作。同样，吸附塔也可以选择。

2）干燥器、滤器

2.4.1.2 A feed air treatment system shall be fitted to remove free water, particles and traces of oil from the compressed air.

3）吸附塔

4）阀组和止回阀组

用于调压（调压阀）以及控制流量（比例阀）

2.2.1.2 The system shall be capable of:

6、具体要求和报警点

1）2.2.2.3 Suitable shutoff arrangements shall be provided on the discharge outlet of each generator plant.

2）2.2.2.4 The system shall be designed to ensure that if the oxygen content exceeds 5% by volume, the inert gas shall be automatically vented to atmosphere.

3）2.2.2.5 Arrangements shall be provided to enable the functioning of the inert gas plant to be stabilized before commencing cargo discharge.

在采用N2模式的时候，当开始供气后的10分钟内，是一直排大气。

If blowers are to be used for gas-freeing, their air inlets shall be provided with blanking arrangements.

用短管

4）显示记录和报警点

2.2.4 Indicators and alarms

2.2.4.1 The operation status of the inert gas system shall be indicated in a control panel.

2.2.4.2 Instrumentation shall be fitted for continuously indicating and permanently recording, when inert gas is being supplied:

2.2.4.5 Audible and visual alarms

2.2.4.5.1 Audible and visual alarms shall be provided, based on the system designed, to indicate: