With the development of society, China's construction industry has also been booming, and there are more and more modern high-rise buildings. These new buildings have the advantages of complex functions, large scale and concentrated personnel, which can bring people a good experience. However, such buildings also have huge hidden dangers, especially fire hazards. Once there is a fire, all kinds of indoor furniture and decoration materials will produce a lot of toxic gases, which will not only affect people's evacuation and escape, but also restrict the normal development of fire fighting operations. In order to improve the building, we need to improve the performance of the air duct according to the specific requirements of the building. The following is an in-depth analysis of this problem.

暖通、空调工程设计中，通风管道系统在穿越不同防火分区时，以及管道系统在平时工况和火灾工况的功能实现，总是带来很多复杂性，使得选择合适的管道系统变的相对麻烦。

In the design of HVAC engineering, when the ventilation pipe system passes through different fire zones, and the function realization of the pipe system in normal and fire conditions, it always brings a lot of complexity, which makes it relatively difficult to choose the appropriate pipe system.

实际工程中，风管在某些部位总是需要具有一定的防火性能，在此我们可以通过很多方式来实现对风管的防火保护。

In the actual project, the air duct always needs to have a certain fire performance in some parts, here we can achieve the fire protection of the air duct in many ways.

防火测试方法

Fire test method

风管在没有借助防火阀的情况下，其耐火性能的表达方式：防火稳定性、完整性和绝热性。

Without the help of fire damper, the fire resistance performance of air duct can be expressed in the following ways: Fire stability, integrity and insulation.

稳定性的丧失发生于：风管的悬挂或固定件已无法使风管保持原有位置，截面发生垮塌。这一性能要求并不适用于内部受火风管在炉内的管段部分。

The loss of stability occurs when the suspension or fixing parts of the air duct can not keep the original position, and the section collapses. This performance requirement is not applicable to the section of internal fire air pipe in the furnace.

完整性的丧失表现为：风管上出现裂纹、洞口或撕裂或者与楼板（墙体）之间出现缝隙，致使火焰或热气穿透。固定或非固定风管在出现移动或变形现象时的完整性评估均包括在本准中。

The loss of integrity is manifested as: cracks, holes or tears appear on the air duct, or cracks appear between the air duct and the floor (wall), resulting in flame or hot gas penetration. The integrity assessment of fixed or unfixed ducts in case of movement or deformation is included in this standard.

绝热性的丧失表现为：炉外风管段的外表面温度上升平均值超过140°或者单点的温度上升超过180°。这一标准同时也指出风管披覆有易燃材料或者内部积存有油脂等，也应当满足风管的防火要求。

The loss of thermal insulation is shown as follows: the average temperature rise of the outer surface of the air duct section outside the furnace is more than 140 ° or the temperature rise of a single point is more than 180 ℃. This standard also points out that if the air duct is covered with flammable materials or has grease accumulated inside, it should also meet the fire protection requirements of the air duct.