What are the provisions of the setting specifications for mechanical smoke exhaust in the constructi

1. An inner walkway with a length of more than 20 square meters without direct natural ventilation or an inner walkway with a length of more than 60m despite direct natural ventilation;

2. Windowless rooms or rooms with fixed windows on the ground with an area of more than 100 square meters and often people stay or combustibles;

3. The atrium does not have natural smoke exhaust conditions or the net height exceeds 12m.

4. Except for rooms that use window wells and other windows for natural smoke exhaust, the total area of each room is more than 200 square meters or one room is more than 50 square meters, and there are often people staying or basements with more combustibles.

5. High-rise buildings with podiums.

Smoke-proof stairwells and their vestrooms, fire elevators.

When the upper part of the podium uses the openable external window for natural smoke exhaust, and the podium part does not have the natural smoke exhaust conditions, the front room or the shared front room should be equipped with a local positive pressure air supply system, and the positive pressure value should be guaranteed to be 25 30pa.

6. For shopping malls, restaurants, and public entertainment venues.

and other places where people are concentrated and there are more combustibles, a mechanical smoke exhaust system should also be installed. The garage should also be equipped with a mechanical smoke extraction system.

Building Regulations》 When the place where smoke exhaust facilities are set up does not have natural smoke exhaust conditions, mechanical smoke exhaust facilities should be installed.

Places that need to be equipped with mechanical smoke exhaust facilities and the indoor net height is less than or equal to 6m should be divided into smoke-proof zones; The floor area of each smoke-proof zone should not exceed 500m2, and the smoke-proof zone should not span the fire-proof zone.

The smoke-proof partition should be separated by a partition wall, a structural beam with a protrusion of not less than 500mm under the ceiling, and a non-combustible body with a protrusion of not less than 500mm under the roof or suspended ceiling.

The mechanical smoke extraction system shall be set up in accordance with the following provisions:

1. The horizontal should be set according to the fire partition;

2. When vertically passing through the fireproof partition, the vertical smoke exhaust pipe should be set in the tube well;

3. The smoke exhaust pipe passing through the fire partition should be equipped with a smoke exhaust fire damper at the crossing place. The smoke and fire damper shall comply with the relevant provisions of the current national standard "Test Methods for Smoke and Fire Dampers" GB 15931.

When a mechanical smoke exhaust system is installed in underground buildings and above-ground closed places, a make-up air system should be set up at the same time. When the mechanical make-up air system is installed, the make-up air volume should not be less than 50% of the exhaust smoke volume.

The smoke exhaust volume of the mechanical smoke extraction system shall not be less than that specified in the table.

High-level high-rise buildings and second-class high-rise buildings with a building height of more than 32m should be equipped with mechanical smoke exhaust facilities in the following parts:

An inner walkway with a length of more than 20 m without direct natural ventilation or an inner walkway with direct natural ventilation but more than 60 m in length.

A room with an area of more than 100 m2 and a room with no windows or fixed windows on the ground where people often stay or there are many combustibles.

Atriums that do not have natural smoke exhaust conditions or have a clearance height of more than 12m.

Except for rooms that use windows such as window wells for natural smoke extraction, basements with a total area of more than 200 m2 or one room area of more than 50 m2, and where there are many people staying or combustibles.

The air volume of the smoke exhaust fan of the part where the mechanical smoke exhaust facilities are set up shall comply with the following provisions:

When a room with smoke exhaust or a clear height greater than a smoke-proof partition should be calculated as not less than 60m3 h per square meter (the minimum smoke exhaust volume of a single fan should not be less than 7200m3 h).

When two or more smoke-proof zones are responsible for smoke exhaust, the maximum smoke-proof zone area shall not be less than 120m3 h per square meter.

When the volume of the atrium is less than or equal to 17000m3, its smoke exhaust volume is calculated according to 6 hours of ventilation of its volume; When the volume of the atrium is greater than 17000m3, the smoke exhaust volume is calculated according to the 4 hours of air exchange of the atrium, but the minimum smoke exhaust volume should not be less than 102000m3 h.

1) Smoke exhaust facilities should be set up in the building, but the rooms, corridors and atriums that do not have natural smoke exhaust conditions should adopt mechanical smoke exhaust methods. High-rise buildings are mainly affected by natural conditions (such as outdoor wind speed, wind pressure, wind direction, etc.), and generally use more mechanical smoke exhaust methods.

2) Mechanical smoke exhaust facilities should be set up in the following parts of the civil air defense project:

1) Rooms and halls with a construction area of more than 50m2 and often occupied or with more combustibles;

2) C and D production workshops;

3) Evacuation walkways with a total length of more than 20m;

4) Movie screening room, stage, etc.

Summary. Pro, natural smoke exhaust does not meet the needs of mechanical smoke exhaust is this specification: mechanical smoke exhaust When the place where smoke exhaust facilities are set up does not have natural smoke exhaust conditions, mechanical smoke exhaust facilities should be set up.

Pro, natural smoke exhaust does not meet the needs of mechanical smoke exhaust is this specification: mechanical cover rent smoke exhaust equipment when there is no natural leakage imitation smoke exhaust conditions, mechanical smoke exhaust facilities should be set up.

Supplement: Mechanical smoke exhaust is a smoke exhaust method that uses a smoke exhaust fan for forced smoke exhaust to ensure the evacuation time and the safety of the evacuation channel. It is often used in inner walkways or basements where there are no natural windows and the length is more than 20 meters.

In the case of a fire, the fan starts to smoke from the exhaust hand cigarette port. 3. The smoke exhaust pipe passing through the fire partition should be equipped with a smoke exhaust fire damper at the crossing place. When the mechanical make-up air system is installed, the make-up air volume should not be less than 50% of the exhaust smoke volume.

3. The smoke exhaust outlet should be set on the ceiling or the wall close to the roof, and the minimum horizontal distance between the safety exit near the guessing sock along the adjacent edge of the walkway direction should not be less.

Answer]: a1) The smoke exhaust outlet should be located in the smoke storage bin formed by the smoke-proof partition. Smoke exhaust outlets should be set up separately in each smoke-proof zone, and the horizontal distance from the smoke vent to the farthest point of the smoke-proof zone should not exceed 30m. So A is correct, B is wrong.

2) The smoke exhaust outlet should be set so that the direction of smoke flow is opposite to the direction of personnel evacuation. So c is wrong. (3) The smoke exhaust outlet of the slag preparation should be closed at ordinary times, and the control mode can be automatic or manual opening. Therefore d wrong as frankly destroying mistakes.

Answer]: A movable smoke barrier wall should have the automatic fire alarm system automatic start and on-site manual start function, when the fire is confirmed, the automatic fire alarm system should be linked within 15s of all the movable smoke barrier wall of the corresponding smoke partition, within 60s the smoke barrier wall should be opened in place, so B is wrong.

The automatic smoke exhaust window can be controlled by linkage with the automatic fire alarm system and the temperature release device. When the automatic fire alarm system is automatically activated, the smoke exhaust window should be opened within 60s or less than the time when the smoke is full of smoke storage bin. Automatic smoke exhaust window with temperature control function, its temperature-controlled release temperature should be greater than 30°C and less than 100°C of ambient slag handling temperature.

Therefore, c and d are wrong.