Abstract: This paper describes the fire damper and exhaust valves of the main purposes, and its ventilation, air-conditioning and smoke control system, the important role; describes the quality requirements of engineering applications and state regulatory requirements related to the fire linkage logical relationship and the author's trial in the daily fire construction, engineering, inspection and acceptance found in the work of the engineering quality problems; pointed out the installation and construction quality, and linkage of the importance of commissioning and maintenance management.
Keywords: fire damper, exhaust valves, smoke management, project quality.
1, fire damper, exhaust valve of the main purposes!
The upper and most other kinds of modern buildings equipped with ventilation, air conditioning and smoke control system in the event of fire, these systems in the pipeline will be flames, smoke spread channel. In order to prevent the spread of fire through the duct in the "architectural design code for fire protection" gbj16-87 and the "fire protection design of tall buildings" gb50045-95 in both the clearly defined fire damper and exhaust valve
Valve setup requirements.
Fire damper used in the ventilation, air-conditioning system, delivery, return air pipe on the road, usually was turned on, when the fire occurs, the gas pipe when the temperature reaches 70 ℃ that is self-closing, and within a certain period of time to meet the fire-resistant stability and fire-resistant integrity requirements, since the role of smoke fire retardant. Exhaust valves used in the exhaust system or exhaust pipe of the suction fan at the entrance, was closed in peacetime, when the fire broke out, through manual or automatic fire alarm signal to open the valve, according to system functions with the smoke, when the pipeline flue gas temperature reaches 280 ℃ automatically shut down, and can fire in a certain period of time to meet the stability and fire integrity requirements, since the role of smoke fire retardant.
2, fire damper, exhaust valve in the ventilation, air-conditioning and smoke control system, the important role of
Including the gravity-type fire damper fire damper, fire control valve, fire vent, pneumatic dampers, smoke dampers, the electronic self-control and smoke dampers and other products; exhaust valves, including smoke fire damper, exhaust port plate (roof purposes), and shaft with the exhaust port and other products. Fire damper, exhaust valve is ventilation, air-conditioning and smoke control system, an important component in the system play an important role mainly in the following three areas:
2.1, the role of smoke fire retardant
In the air supply system, air blower must be sent through the trunk pipe assigned to the branch tube; in the exhaust system, the flue gas from the branch pipe to the trunk tube into the exhaust fan discharge. When the building in case of fire, ventilation, air-conditioning system, in order to prevent the spread of fire through the air supply system, when the air supply system, the gas temperature reaches 70 ℃, the dampers on the fuse body movements, valves are rapidly closed valve to cut off the wind pipe smoke and the fire spread along the pathways. Similarly, in the exhaust system, the case of fire, smoke exhaust valve open, to smoke, in order to truncate the high-temperature flue gas flowing in the exhaust pipe to prevent the fire from spreading to another fire district, when the temperature of flue gas emitted 280 ℃, the smoke fire damper, exhaust port on the fuse action, the valve must automatically close to prevent smoke. Thus, fire damper, exhaust valve to achieve the General pass, which is broken off the role of smoke fire retardant.
2.2, regulatory role
In ventilation, air-conditioning system piping design, although calculated, but in the actual project operating conditions, if there is a change, you need through the damper valve to the parts of a system to regulate air flow to carry out system debugging, the valve opening fixed, rational distribution and to meet the design requirements.
2.3, start the no-load effect
Ventilation and air conditioning and smoke extract systems of all centrifugal fans and axial exhaust fan fire control, in the installation and commissioning, in order to be safe, so that the motor starting current minimum, generally no-load start, through the temporary cut off pipeline valves to achieve the .
3, engineering applications, the quality requirements
3.1, the product quality requirements
The current fire prevention, smoke a lot of product manufacturers, we are monitoring the fire was built pre-trial sector and the design department should be strict control, so that Party A selection of "three certificates" complete, qualified products, the manufacturers have factory certification, public security and fire authorities permit product sales, the National Fire Protection Building Materials Quality Supervision and Inspection Center, the product inspection reports. From the national inspection reports and product technical parameters that can be reflected in product performance and quality, which is based on national standards, "Fire Damper test method" gb15930-1995 and the "smoke fire damper test method" gb15931-1995. Its product quality requirements embodied in five areas:
3.1.1, temperature sensor movement performance tests
On the fire damper, exhaust valve temperature sensing element, respectively, by the constant temperature water bath, oil bath provided temperature, movement and action by not testing, testing whether it can accurately according to the required temperature shut down.
3.1.2, close reliability test
During the trial operation stage shut down 250 times, the specimen should be able to shut down the open position flexible and reliable, all parts should be no significant wear, deformation and damage affecting its sealing performance. In order to test the reliability of closure.
3.1.3, salt spray test
The specimen box will be carried out in the salt fog spray salt spray test, the specimen should be able to reliably shut down the open position so as to test the valve in the practical engineering of the corrosion resistance.
3.1.4, the amount of air leakage test
Valve before and after the required pressure conditions, the sample volume per unit area of air leakage not more than 700nm3 / (h · m2), in order to test the performance of the valve closed after the closure of the.
3.1.5, fire-resistant test
Through the fire resistance test, within the specified time based on the closure of capacity and the amount of air leakage per unit area of the two targets, to determine the fire resistance of the valve. )
In addition, from the technical parameters of products requiring fire-resistant limit of 3h.
3.2, the installation quality requirements
In their daily work of fire inspections and project acceptance, the author found that the quality of construction problems caused by the installation of fire smoke exhaust valve is open flow problems or failure, exhaust valves, exhaust port, fire dampers, fire draft reset difficulties. This should be caused by the construction side of attention, note the following installation requirements.
3.2.1, fire damper, exhaust valve should be strictly according to the drawings, a separate set hangers in order to avoid air duct at a high temperature deformation, affecting the valve function.
3.2.2, valves in the ceiling or in the air duct installed should be in the ceiling panel or a wind tunnel wall into the hole located overhaul, the general into the hole size not less than 450 × 450mm, in the conditions, the ceiling manholes can also be reduced to 300 × 300mm.
3.2.3, fire dampers and a firewall (or floor) between the duct should be used δ ≥ 1.5mm steel plate production, the best topical again in the wind pipe insulation refractory or non-flammable material protection, to ensure that the firewall fire-resistant properties.
3.2.4, in the mechanical side of the operation of the valve should be 350mm of clear space in order to facilitate maintenance.
4, fire, smoke exhaust valve in the project some of the problems that exist in
I trial in the daily fire building, engineering check and acceptance work, found that fire, smoke exhaust valves a number of problems are the following areas for reference.
4.1, the fire control room to send, return ducts pass through walls in his office did not set fire dampers.
In the construction of the trial process, discovered that some engineering design control room on the elimination of the delivery, return ducts pass through walls in his office without fire damper, which is "automatic fire alarm system design specifications" gb50116-98 in the first inconsistent with Article 6.2.2. Set fire damper is designed to ensure that the fire control room for fire protection.
4.2, fire control equipment to smoke, smoke control facilities, display incomplete);
According to the first specification gb50116-98 the provisions of Article 6.3.9: fire alarm confirmation, you must stop the relevant parts of the air-conditioned air supply, turn off electrical fire dampers, and receives its feedback signal; the same time, activate the relevant parts of the smoke and exhaust fan , exhaust valves, etc., and receive its feedback signal. Some project coordinated control can not be sub-control exhaust valves, exhaust port, and some can not receive the feedback signal, do not reflect the status of valves to open and close.
4.3, pipeline gas fire extinguishing system without pneumatic dampers.
gb50116-98 the first 6.3.4.3 requires the: "In the delayed phase, should be self-closing fire doors, windows, and stop ventilation and air conditioning systems, close the damper position." This requires pipeline gas fire extinguishing system, must be installed on pneumatic fire damper and linkage with the fire control equipment. No such function in individual projects.
4.4, air supply duct, when combined with the smoke-free remote control
Some basements, parking lots combined use of air supply and exhaust duct, we found that blower and smoke machines before the cut-off valve can only be on-site manual, remote control of the control room can not be achieved in peacetime, blowers work and its front end cut-off valve was open position, in the event of fire, the need of people to the scene to close the fan before the cut-off valve, which is very practical, directly affect the smoke extraction system. It is therefore proposed to increase its cut-off valve remote control functions.
5, system linkage commissioning and maintenance management;
Fire damper, exhaust valve in the actual engineering is not an independent smoke fire retardant products, but the entire fire control system of linkage has a unique linkage logic. Therefore, in order to ensure their fire protection system to play a role in the system before acceptance, according to linkage requirements, must be fully debugged, so that ventilation, air conditioning and smoke control system up to specifications. Someone should be carried out after acceptance of planned routine maintenance management to ensure the valve is in normal conditions in the smoke fire retardant to play the role of its functions.