Contact

    Chengdu Huibao Energy Technology Co., Ltd.
  • Contact :Mr.Li
  • Tel:028-82213905
  • Mobile:13980030203
  • Fax:028-82213905
  • Email:lizh6688@163.com
  • Website:en.cdhbjn.com
  • Address:Economic Development Zone , Chengdu City , Sichuan Province , Chongzhou innovation Lixing Avenue home of C49

Details of the news首页 > Corporate News > Introduction of smoke control system in smoke control design by wholesaler of single color steel phe

Introduction of smoke control system in smoke control design by wholesaler of single color steel phe

Source:http://en.cdhbjn.com/news346249.html       Begintime:2018-04-13 10:17:00

Introduction of smoke control system in smoke control design by wholesaler of single color steel phenolic board

1. Calculation method of pressurized air supply

① . differential pressure method: when the evacuation exit door is closed, the pressurized part maintains a certain positive pressure value.

Ly = 0.827xax Δ P1 / nx1.25x3600 0.827 -- air leakage coefficient

A is the total area of calculated air leakage of door gap (M2). The width of door gap is 0.002-0.004m

Δ P -- pressure difference between two sides of door joint (PA): 40-50pa for smoke proof staircase, 25-30pa for front room shared by fire elevator, and 1.25 additional coefficient at the non tight position

N -- index (generally 2)

② . wind speed method: when opening the evacuation door of the fire floor, it is necessary to maintain the air supply volume required for a certain wind speed at the door opening

LV=nxFxνx(1+b)x3600/a

V -- average wind speed at the opening of the door, 0.7 ~ 1.2 (M / s)

F -- opening area of one door (M2)

A -- back pressure coefficient, according to the sealing degree of the pressurization room, take 0.6 ~ 1.0b -- additional rate of air leakage, take 0.1 ~ 0.2N -- the calculated number of simultaneously opened doors, take 2 for multi-storey buildings and buildings below 20 floors, and take 3 for buildings above 20 floors.

③ Compare the values of ly, LV and fire code pressurized air supply meter to determine the pressurized air supply.

2. Difficulties in calculation of pressurized air supply

① The pressurized air supply volume of the shared front room is related to the number of floors of the building and the number of open doors; the value of n is directly related to the number of open air outlets. Two tuyeres are calculated for floors below 20 and three tuyeres for floors above 20. Finally, the section wind speed of the check door is taken as the standard. This requirement shall also be followed in fire control.

For example: when the number of building floors is less than 20, the pressurized air supply volume of the shared front room is 12000 ~ 16000m3 / h, and the current size of the door opening is 1.2 x 2.1, open the two-layer air supply outlets, and the air speed of the door opening is 0.66 ~ 0.88m/s, which meets the air speed requirements of the door opening. When the air supply outlet on the third floor is opened, the wind speed of the door opening is 0.441-0.59m/s, which does not meet the wind speed requirements of the door opening.

② When there are two or more rooms in the current room, the air volume shall be determined by multiplying the calculated value by 1.5 ~ 1.75. When the door is opened, the air speed through the door shall not be less than 0.7m/s. The door here does not include the front door of the smoke-proof staircase. The wind pressure of the smoke proof stairwell is greater than that of the front room.

③ Pressure air supply of underground smoke proof staircase

In a multi-storey building, if there is only one evacuation staircase underground, n is 1, and the wind speed V at the door opening should be increased appropriately, which should be 0.9 ~ 1.2m/s. The calculated value is taken directly and is not compared with the table.

LV=nxFxνx(1+b)x3600/a

=1x1.6x2.0x0.9x1.1x3600/0.8

=14256m3/h

Other basement pressurized air supply can refer to this method.

④、地上部分防烟楼梯间及合用前室均采用自然排烟,地下部分防烟楼梯间及合用前室需要机械加压送风的情况?

分析:地下防烟楼梯间及合用前室分别加压送风。(按照建规执行)

⑤、地上部分合用前室采用机械加压送风,地下合用前室风量怎样计算?

分析:可以合用系统。原因是控制系统可以实现着火层及其上一层的防烟控制;而且考虑一个着火点。

⑥、加压送风系统的超压问题

a、设置泄压阀,且在穿越防火墙处设置70℃防火阀,泄压板的开启面积公式:

F=(LV-LY)/3600x6.41 F-泄压阀阀板的开启面积(m2)

LV-加压送风量(m3/h)

LY-当疏散通道门关闭时,加压部位保持一定的正压值所需送风量(m3/h)

b、采用旁通阀,在楼梯间及前室合用前室适当的位置设压力传感器,控制加压送风机出口处的旁通泄压阀,调整余压值。

3、其他规定

①、4.5.5-3条:机械加压送风口不宜大于7m/s,排烟口不宜大于10m/s,公共聚集场所不宜大于5m/s,自然补风口不宜大于3m/s。

②、机械加压送风管道和用于机械排烟补风管道不宜穿过防火分区或其它火灾危险性较大房间,当必须穿越时,应在穿过处设置防火阀,加压送风管道防火阀的动作温度为70℃,补风管道防火阀的动作温度可为280℃

理解:在送风风速很大的情况下,即使环境温度较高,风道内温度也不可能达到70℃;补风(工业厂房)也可补大于70℃的空气。补风管道防火阀的动作温度可为70℃或280℃。

③、4.9.3-2条:靠外墙的防烟楼梯间每5层内可开启外窗的总面积之和不应小于2.0㎡,且顶层可开启面积不宜小于0.8㎡。

④、4.10.11条:未能设置在独立管道井内的加压送风管应采用耐火极限不小于1.0h的防火风管。注:当加压送风管采用钢板制作时,宜采取适当加厚钢板厚度或采用防火板包覆等措施,以满足耐火极限不小于1.0h的要求。

问题:排烟管道耐火极限是多少?

答案:经验,1.2mm厚钢板耐火1小时。

2mm厚钢板耐火1.5小时。

⑤、技术措施中4.10.9-10防烟楼梯间加压送风口可采用自垂百叶式或常开百叶式风口,并应在加压风机压出段上设置防回流装置或电动调节阀。

问题:自垂百叶式风口在加压风机压出段上也应加回流装置。

原因:自垂百叶风口由于重量轻,在风压很小的情况下就被吹开,所以要在加压风机压出段上加回流装置。

④ . natural smoke exhaust is adopted for the above ground smoke-proof staircases and shared antechambers, and mechanical pressure air supply is required for the underground smoke-proof staircases and shared antechambers?

Analysis: the underground smoke-proof staircase and shared front room are pressurized for air supply. (in accordance with the construction regulations)

⑤ . mechanical pressurized air supply is adopted for the shared front room above the ground. How to calculate the air volume of the shared front room below the ground?

Analysis: the system can be shared. The reason is that the control system can realize the smoke control of the fire layer and its upper layer, and consider a fire point.

⑥ Overpressure of pressurized air supply system

a. The pressure relief valve is set, and 70 ℃ fire damper is set at the place passing through the firewall. The opening area formula of the pressure relief plate is as follows:

F = (lv-ly) / 3600x6.41 f-opening area of pressure relief valve plate (M2)

LV - pressurized air supply volume (m3 / h)

LY - air supply volume required to maintain a certain positive pressure value at the pressurized part when the evacuation exit door is closed (m3 / h)

b. The bypass valve is adopted, and the pressure sensor is set at the appropriate position of the shared front room of the stairwell and the front room to control the bypass relief valve at the outlet of the pressurized blower and adjust the residual pressure value.

3. Other provisions

① 4.5.5-3: the mechanical pressure air supply outlet shall not be greater than 7m / s, the smoke exhaust outlet shall not be greater than 10m / s, the public gathering place shall not be greater than 5m / s, and the natural air supplement outlet shall not be greater than 3m / s.

② The mechanical pressurized air supply pipe and the air supplement pipe for mechanical smoke exhaust should not pass through the fire compartment or other rooms with high fire risk. When it is necessary to pass through, a fire damper should be set at the crossing place. The action temperature of the fire damper of the pressurized air supply pipe is 70 ℃, and the action temperature of the fire damper of the air supplement pipe can be 280 ℃

Understanding: in the case of a large supply wind speed, even if the ambient temperature is high, the temperature in the air duct can not reach 70 ℃; make-up air (industrial plant) can also make up air higher than 70 ℃. The operating temperature of the fire damper of the air make-up pipe can be 70 ℃ or 280 ℃.

③ 4.9.3-2: the sum of the total area of the openable external windows in every 5 floors of the smoke-proof stairwell near the outer wall shall not be less than 2.0 ㎡, and the openable area of the top floor shall not be less than 0.8 ㎡.

④ 4.10.11: the pressurized air supply pipe which is not set in the independent pipeline well shall be fire-resistant air pipe with a fire resistance limit of not less than 1.0h. Note: when the pressurized air supply pipe is made of steel plate, it is advisable to take appropriate measures such as thickening the thickness of steel plate or covering with fireproof plate, so as to meet the requirement that the fire resistance limit is not less than 1.0h.

Question: what is the fire resistance limit of the exhaust pipe?

Answer: experience, 1.2mm thick steel plate fire resistant for 1 hour.

2mm thick steel plate is fire resistant for 1.5 hours.

⑤ 4.10.9-10 in the technical measures, the pressurization air supply outlet of the smoke proof stairwell can be of the self hanging shutter type or the normally open shutter type, and the backflow prevention device or the electric control valve shall be set on the pressing section of the pressurization fan.

Problem: a reflux device should also be added to the pressing section of the pressure fan at the self draping shutter type air outlet.

Cause: due to the light weight, the self draping shutter vent is blown open when the wind pressure is very small, so a reflux device should be added to the pressing section of the pressurized fan.

028-82213905
hotlines for national customer service

Address:Economic Development Zone , Chengdu City , Sichuan Province , Chongzhou innovation Lixing Avenue home of C49