The design of the gateway platform with air pressure in the administrative building
We have designed a vestibule-gateway with air overpressure in the administrative building to cut off the evacuation staircase from the basement.
DESIGNING A TAMBUR GATEWAY WITH AIR
In the building at the address of Moscow, the device of a vestibule with air overpressure is provided for cutting off the evacuation staircase from the basement floor.
The building is public, located in Moscow.
h2 = 2.3 m - the height of the 2nd floor (from the floor of the 1st floor floor to the floor of the 2nd floor)
hdr = 1.9 m - height of doorways
Fdr = 1.7 m² - door area
n = 3 pcs - the number of doors of the gateway
hI = .0 m - mark of the i-th above-ground floor where the gateway is located
h-I = -3.0 m - mark of the i-th underground floor relative to 0.000, where the gateway is located
h-N = -3.0 m - depth Location of the vestibule: on the underground floor.
Existing brick partitions have fire resistance REI120.
In the vestibule of the gateway, three doors are provided with a direction in the direction of evacuation, fire-resistance REI60.
The protection of people on the evacuation routes is provided by a complex of space-planning, ergonomic, constructive, engineering and organizational measures. Evacuation routes within the premises should ensure the safe evacuation of people through the evacuation exits from this room without taking into account the fire extinguishing and smoke protection equipment used in it.
Evacuation routes within the premises should ensure the possibility of safe movement of people through emergency exits from this room without taking into account fire extinguishing agents and personal protective equipment against dangerous fire factors.
The fire hazard of building materials of the surface layers of structures (separation and cladding) in rooms and on evacuation routes outside the premises should be limited depending on the functional fire hazard of the room and building, taking into account other measures to protect the evacuation routes and the functioning of fire-fighting systems. protection.
Activities and facilities designed to rescue people, as well as exits that do not meet the requirements for evacuation exits, are not taken into account when designing evacuation routes from premises and buildings.
3. AIR SUPPORT DESIGN
Design outdoor temperature: -28C
Estimated temperature of indoor air: + 20C
Estimated wind speed: 4.9m / s
Internal pressure in the protected vestibule:
Pri = 20 - g ∙ (hi + 0.5 hdr) (ρa - ρr) = 20 - 9.81 (0 + 0.5 1.9) (1.29 - 1.2) = 19 Pa
Pr-i = 20 - g ∙ (hn- (h-i + 0.5 hdr) (ρa - ρr) = 20 - 9.81 (-3 - (- 3 + 0.5 1.9) (1.29 - 1.2) = 21 Pa
ρr = 353 / (Tr + 273) = 353 / (20 + 273) = 1.20 m³ / kg - air density in the building
ρa = 353 / (Ta + 273) = 353 / (-28 + 273) = 1.29 m³ / kg - the density of the outside air
Sdr = 5300 / ρa = 5300 / 1.29 = 4108.53 m³ / kg - characteristic of the smoke resistance of the doors of the lock room;
Flow in the gateway gateway:
Gr = n · Fdr · (20 / Sdr) ½, kg / s
Gr = 3 · 1.71 · (20 / 4108.53) ½ = 0.358 kg / s
Fan feed:
Lv = Gr · 3600 / ρa = 0.358 · 3600 / 1.29 = 1000 m³ / h
According to SP7.13130.2013, clause 7.15, section c) for the vestibule-gateway, located at the exit to the unstable staircases, the calculation is also carried out to ensure the speed in the doorway opening of at least 1.3 m / s:
Dimensions of the door at the exit to the staircase 1.9х0.9 = 1.7m2
The required air flow will be: 1.7m2 ∙ 1.3m / s ∙ 3600 = 8000m3 / h.
Grounding and equipotential bonding.
To protect people from electric shock applied: grounding, protective shutdown.
To ground the equipment or its parts according to the Rules for Electrical Engineering of Claims 1-7 to 46
The use of a neutral conductor coming from the neutral of a generator or transformer on a switchgear panel is not allowed as a grounding conductor.
The resistance of the grounding device, at any time of the year should be no more than 4 ohms at line voltages of 660V, 380V and 220V, according to EIR 1-7-62.
As natural earthing to use the elements and designs, according to PUE 1-7-70.
To connect grounding conductors to the grounding lines with at least two conductors connected to the grounding conductor in different places, according to EIR 1-7-71.
For artificial earthing, apply angular steel 40x40x4, steel round 0 12 mm, 2-3 m in length, according to PUE 1-7-72, 1-7-51.
For grounding and neutral protective conductors, use steel strip, according to the PUE 1-7-76:
The connection and connection of grounding and neutral protective conductors should be carried out in accordance with EIR 1-7-90, 1-7-94 and GOST 10434-76 according to the 2nd class of connections.
According to the technical circular (Association “Roselectromontazh” dated 05/11/2000 No. 6-1 / 2000, each electrical installation should have a main potential equalization system connecting the following conductive parts:
supply line protective conductor;
a grounding conductor connected to a natural or artificial earth ground;
metal pipe communications.
All contact connections must comply with the requirements of GOST 10434 for class 2 contact connections.
Grounding protective PE conductor of the supply line in the TN-C-S system. A grounding conductor connected to a re-earthing earthing switch at the building entrance (if there is a grounding conductor);
To be connected to the main potential equalization system, all the indicated parts must be connected to the main grounding bus, according to the Rules of Electrical Code 1.7.119-1.7.120, with the help of potential equalization system conductors.
3. INTEGRATION OF THE SYSTEM OF THE SUPPORT INTO THE EXISTING AUTOMATIC FIRE ALARM SYSTEM
When forming a fire signal in the existing automatic fire alarm system, the control device generates a “dry contact” type output connected to an overpressure fan control panel and an electromechanical valve actuator. The fan starts and opens the valve.
Valve KLAD-2 is equipped with Belimo 220V electromechanical actuator.
The control panel fan PD1, located in the room №2. To the shield to bring a signal about the formation of a fire from the existing APS system