【 Weak current College 】 fire damper, exhaust valve in the air conditioning system and maintenance management

1. fire damper, exhaust valve main use

Senior and other modern buildings are mostly equipped with ventilation, air conditioning and smoke control system, in the event of fire, these systems of pipeline will become the flame and smoke spread of channel. In order to prevent fire spread through the air pipe, in the architectural design fire protection standard "GBJ16-87 and the tall buildings design fire protection standard" GB50045-95 are clearly provides the fire damper, exhaust valve set requirements.

Fire damper used for ventilation, air conditioning system, ventilation pipes, usually are opened, when the event fires, the pipeline gas temperature 70 ° c is to shut down, and over time to meet fire resistance stability and fire requirements, since every other smoke fire effect. Exhaust valves used in exhaust system pipes or exhaust fan of suction at the entrance, is turned off, when a fire occurs, through the fire alarm signal opens valve manually or automatically, depending on the system functions with smoke, when pipe flue gas temperature reached 280 ° c are automatically turned off, and at one time, meet fire resistance stability and fire requirements, since every other smoke fire effect.

2. fire damper, exhaust valve in ventilation, air conditioning and smoke control system in the important role of

Fire dampers include gravity fire damper, fire protection control valves, fire valves pneumatic air, fire, smoke fire dampers, electronic controlled smoke fire damper, exhaust valve products; including exhaust fire damper, exhaust orifice plate (ceiling), shaft with exhaust vents, etc. Fire damper, exhaust valve is ventilation, air conditioning and smoke control system in the important components in the system play an important role in the following three aspects:

2.1, smoke fire effect

In ventilation systems, air blower must be sent out through the main tube to tube; in the exhaust system, the smoke from the branch to thetrunk pipe, into the exhaust fan. When building a fire, ventilation, air conditioning system, in order to prevent fire spread through the air supply system, when the air supply system gas temperature 70 ° c, fire valve bodies, valve on the fuses are rapidly closing valve, cut off the smoke and the fire spread along the pathways of the air duct. Similarly, in the exhaust system, fire, smoke, smoke exhaust valve opening, in order to cut high temperature flue gas flow in the exhaust pipe to prevent the spread of fire to another fire partition, when discharged flue gas temperature reached 280 ° c, smoke fire dampers and smoke exhaust port fuses, valve must be closed automatically, preventing smoke. This shows that the fire damper, exhaust valve did the general clauses, which breaking the fault of other tobacco flame effect.

2.2, regulation of

In ventilation, air conditioning system piping design, although the calculation, but the actual project's operation if there are any changes, you need to pass the fire damper valve parts of the system air flow adjustment system debugging, set the valve to open degree fixed, reasonable allocation to meet design requirements.

2.3, start, no role

Ventilation and smoke extraction system all centrifugal fan and fire special exhaust axial fan installation, debugging, for security reasons, the motor start current minimum, typically no startup, through the valve temporary truncated line.

3. application of quality requirements

3.1, product quality requirements

Current fire and smoke product manufacturers, we fire supervision and examination Department and design departments should be strict, let the party a selection of "three certificates" complete, qualified product, that is, to have the manufacturer's factory certification, fire authorities of product sales license, national fire building materials quality supervision and test center of product test reports. Report from the national inspection and product technical parameters to reflect the product performance and quality, which is the national standard of the fire damper test method "GB15930-1995 and the smoke fire valve test method" GB15931-1995. Its product quality requirements should be considered the five aspects:

3.1.1, temperature sensors action performance test

On the fire damper, exhaust valve of liquid components, by constant temperature water bath, oil bath temperature, through the actions and test, test its action is required to close the temperature accurately.

3.1.2, close, reliability testing

On the test bench close operation 250 times, specimen should be can't open position flexible and reliable manner in all parts should be turned off, no significant wear, deformation and damage of the seal performance. To test the reliability of off.

3.1.3, salt spray test

To the specimen in the salt spray fog test box, the specimen should be able to reliably from the open position, as a test valve closed in practical engineering corrosion resistance.

3.1.4, air leakage test

Body before and after the pressure conditions, the specimen to the area of air leakage rate is not more than 700Nm3/(h · m2), in order to test the valve closes after the sealing performance.

3.1.5, fire resistance test

Through the fire resistance test, depending on time of close and air leakage rate per unit area of the two indicators to determine if the fire resistance of the valve.

Also from the product's technical parameters requires its fire resistance to 3h.

3.2, installation quality requirements

In the daily fire inspection and acceptance the work, the author found that because of quality problems caused by the installation of fire smoke exhaust valve open failed or failing, exhaust valve, exhaust valve, fire prevention, fire safety outlet reset difficulties, etc. This should cause construction party, note the following installationrequirements.

3.2.1, fire damper, exhaust valve should strictly follow the map construction, separate set hangers, to avoid air pipe deformation at high temperatures, affect valve function.

3.2.2, valves in the ceiling or on the installation of wind road, in the ceiling or windRoad wall set maintenance into the hole, General-in-hole size not less than 450 × 450mm, conditionality, ceiling-based maintenance hole can also be reduced to 300 × 300mm.

3.2.3, fire valves and the firewall (or floor) air duct should use δ = 1.5mm plate making, BC in the wind pipe insulation and refractory materials for external or non-combustibility material protection, to ensure that the fire performance of the firewall.

3.2.4, in the operation of mechanical valve side should have a clear space 350mm to facilitate maintenance.

4, fire, smoke exhaust valve in engineering problems

4.1, fire control rooms of sent, returned to the air duct in the through-wall fire dampers are located.

In the examination process, found that some of the engineering design of sent on eliminating control room, air tube in its wall not fire dampers, and the automatic fire alarm system design code GB50116-98 first section 6.2.2. Located fire damper is designed to ensure the fire safety of fire control room.

4.2, fire control equipment on smoke, smoke extraction facilities control, displays the function does not complete

According to the specification in section 98 GB50116-6.3.9 requirements: fire alarm after confirmation, you must stop the relevant parts of the air conditioning, close the electric fire dampers, and receive their feedback signal; at the same time start the relevant parts of the smoke and exhaust fans, exhaust valve, etc., and receive their feedback signal. Some engineering linkage control cannot partition control exhaust valve, exhaust vents, and some can not receive their feedback signal, do not reflect the valves open and close position.

4.3, pipeline gas extinguishing system no pneumatic fire damper.

GB50116-98 in the article: "6.3.4.3 in delay phase, should automatically close fire doors, Windows, ventilation and air conditioning systems, stopping off for parts of fire dampers. " This requires pipeline gas fire extinguishing system, you must install pneumatic fire dampers, and fire control equipment linkage. In individual projects without this feature.

4.4, air supply and exhaust and air duct without remote control

Some of the building's basement, garage with air supply and exhaust smoke with air channel, we found the blower and smoke machines before the cut-off valve only site manually, you cannot achieve the control room of the remote control, usually, blowers, its front side of the valve is opened, in the event of fire, the people to the site to shut down before fan stop valves, which are not actual, direct impact on the exhaust system. Therefore, it is recommended that the valve increases remote control function.

5, System commissioning and maintenance of linkage

Fire damper, exhaust valve in practical projects are not stand-alone smoke fire products, but in the entire fire control system has its own unique linkage logical relationship. Therefore, in order to ensure its role in fire control system, system acceptance before, according to the linkage requirements that must be fully debugged, ventilation, air conditioning and smoke systems meet code requirements. Should the specialist after acceptance for planned routine maintenance management to protect the valve body is in good condition, in smoke fire to play its role.