First, the pipeline, the positioning of equipment and e […]
First, the pipeline, the positioning of equipment and elevation cross problem
At present, HVAC project design drawings are basically CAD drawing, installation of professional design Although the drawings before drawing on the pipeline and the equipment of the initial planning, but in the construction drawing before the map is often not detailed proofreading, often caused The professional construction plans in the pipeline elevation, positioning cross serious, to the project quality management, coordination caused great difficulties. For a comprehensive building, the ceiling space has air conditioning terminal equipment, return air duct, exhaust pipe, chilled water pipes, condensate pipes, sprinkler, fire pipe, electric bridge and other professional pipeline. In the case of insufficient drawings marked by the construction of the map is often the first installation of the pipeline construction is very convenient, after the installation of the pipeline construction is very difficult, can only be installed in the location or elevation should not be installed on the quality of the project can not even use, Cause rework.
1, pipeline engineering design principles
Depending on the performance and use of the pipeline, the pipes in the building can be broadly divided into the following categories:
①, water supply pipes: including living water, fire water, water production;
②, drainage pipes: including domestic sewage, domestic wastewater, fire and drainage, rain, other drainage;
③, water pipes: including water collection and water supply;
④, heat pipe: including heating, hot water supply and air conditioning air handling equipment required for steam or hot water;
⑤, gas pipeline: a gas fuel, liquid fuel points;
⑥, air ducts: including ventilation works, air ducts in various types of ducts, and some of the production equipment required for compressed air pipe;
⑦, for power distribution lines or cables: including power distribution, lighting distribution, weak power system distribution, including weak parts, including shared TV antenna, communications, radio and fire alarm system.
2, should be taken seriously the design of the duct
The height of the ceiling depends largely on the size of the duct section height. Duct traces should not be too long, otherwise the construction is difficult, other pipelines are difficult to arrange. Such as a shopping mall maximum duct cross-sectional area of 2400mmx500mm, duct cross-sectional area, the room must be large, the engine room is also large noise, return air organization difficult. If the duct is short, select the fan power can be smaller, then you can use the horizontal unit mount, the room set on the more flexible.
Therefore, the rational arrangement of the professional pipeline, improve the effective use of space for the building, the need for close cooperation and coordination of professional designers.
Second, HVAC system equipment noise and handling
Air conditioning terminal equipment running noise exceeded, HVAC project is often encountered in the equipment noise problems. As the fan coil technology is more mature, many domestic manufacturers of fan coil products can be marked noise indicators. And the large amount of air conditioning units of the situation is not satisfactory, often measured by the noise than the manufacturers to provide a lot of sample parameters of the product. Therefore, the design to be marked on the equipment noise requirements, the design of the use of large air volume air conditioning units should consider sound insulation measures. When the air-conditioning equipment approach should be timely out of the box inspection, large air-conditioning unit is not installed before the best power test run and found that excessive noise should be replaced, return or modify the perfect muffler measures to avoid the project into the commissioning stage only to find air conditioning units Excessive noise caused by rework situation.
①, equipment installation
The new fan and the air conditioner are installed with a spring damping damper. The fan and the duct are connected with a soft connection. The fresh air unit and the water pipe are connected with a soft joint. The fan coil is connected with a spring hook. The air conditioning room for sound-absorbing treatment, such as air-conditioning room in the use of sound insulation materials made of envelope structure to prevent equipment noise rumor, or in the room paste sound-absorbing material: the use of concave and convex acoustic board as the engine room wall or ceiling , To enhance the sound absorption effect; the engine room should minimize the provision of doors and windows, and the doors and windows should be set up with sound-absorbing doors and windows or sound absorption blinds, to minimize equipment noise rumor.
②, water pipe installation
Water pipe installation to strictly enforce the national norms, chilled water trunk and cooling hose hanger to use spring vibration hanger, and the hanger can not be fixed on the floor, should be fixed on the beam, or between the beam and beam Steel beam fixed. Water pipes through the floor or wall must be used casing, and between the casing and the water pipe with flame retardant materials.
③, wind system installation
Duct installation and installation should be strictly in accordance with national norms for the construction of the fan inlet and outlet installation of the impedance muffler, fresh air imports at the use of silencer louvers, the appropriate part of the duct set muffler, air duct elbow set silencers elbow, air conditioning and fresh Muffler external use of high-quality insulation material insulation, and the same as the static pressure box within the excellent attraction materials. As the return air duct are used low wind speed, large air volume to reduce noise, duct cross-sectional area is relatively large, if the duct installation strength and its overall stiffness is not enough, it will produce friction and vibration noise. It is recommended to use a rubber damping cushion as far as possible to ensure that the duct does not produce vibration noise.
Third, air conditioning water system water cycle problem
Water system central air conditioning construction of the most critical aspects of the construction problems will directly affect the normal operation of the system. Central air conditioning chilled water system is the most common problem is chilled water system pipeline circulation is poor. One of the reasons for the poor pipeline circulation is the pipeline due to the professional pipeline cross, the construction is not coordinated to deal with, resulting in pipe network there are many airbags, affecting the pipe network cycle. Second, air conditioning water system pipeline cleaning is not clean, a direct result of air conditioning water system blockage.
Fourth, the condensation dripping problem
Resulting in air conditioning system in the commissioning and operation of the reasons for condensation dripping, summed up mainly: pipeline installation and insulation issues, pipes and fittings, pipes and equipment is not tight connection between. The main reason for the leakage caused by pipeline installation is not strictly abide by the operating procedures. Pipes, pipe materials, poor quality, approach is not carefully checked. The system does not strictly follow the standard hydraulic test.
Due to the condensate pipeline is too long, in the installation of the collision with the ceiling or slope is difficult to ensure that even condensate pipe down the slope caused by dripping phenomenon; air conditioning unit condensate pipe because there is no water seal (negative pressure) and unit air conditioning condensate can not be ruled out.