Ventilation system engineering how to debug

Ventilation, air-conditioning project is a very important system in modern buildings, including air conditioning, ventilation, smoke and water systems and hot and cold sources of systems. Commissioning work after the completion of the installation of the system is a key process in the construction of ventilation and air-conditioning engineering, is the assessment of the air-conditioning area of temperature and humidity, airflow organization and so on whether to achieve the design parameters and to meet the requirements of the production process to test the quality of engineering design and construction quality of an important link. Especially the smoke control system is related to the use of the whole building function and safety, is the construction project can be successfully delivered to the premise of use. I based on many years of experience in commissioning, combined with the Tianjin Metro Line 1 Nanlou station and the interval of the smoke system commissioning acceptance as an example, briefly explain the technical points of the ventilation and air conditioning engineering system commissioning. 1, the general principles of system commissioning and examples Introduction The commissioning of the ventilation and air conditioning system is a comprehensive work, other related professions such as water, electricity, equipment and fire and remote control, such as close cooperation and coordination, can be carried out smoothly. And in the air-conditioning units, fans and other equipment after the completion of stand-alone commissioning. Tianjin Metro Line 1 is a public **** building, based on the original subway line for expansion, additions to extend the trip. Nanlou station for the underground island-type double-deck station, is a new station, negative two for the platform level, the station hall in the first floor. Platform width 11m effective length of 120m, divided into public **** area and equipment management area; station hall is also divided into public **** area, equipment management area. Station hall, platform public **** area each set up two smoke partition. The two ends of the station are set up to send, exhaust ducts and send, exhaust kiosks, by four reversible fans send and exhaust air. 2, the general content of the system commissioning and testing projects (1) tight performance testing. According to the requirements of different leakage, air leakage test (specific requirements are not detailed here). Requirements must be tested for air leakage should be qualified measuring equipment sub-system segmentation test. Wind leakage test should be carried out on the basis of qualified light leakage test. (2) In order to realize the purpose of light leakage detection method, the duct must be inside and outside of a certain intensity of the safety of the light source on one side, the other side of the dark environment, so that in the dark side of the visual inspection by the light side of the duct through the holes, holes, gaps in the leakage of the light point. So we choose to move slowly in the pipe after dark 100 ~ 200W safety lights and turn off the construction of lighting in order to improve the reliability of the test. The light leakage method should pay special attention to the elbow, tee, cross, reducer and open branch pipe and other places to strengthen the test. Low-pressure air ducts per 10m seam, the leakage point shall not exceed 2, and 100m seam average is not more than 16 for qualified. Medium-pressure air ducts per 10m seam, the leakage point shall not exceed 1, and the average of 100m seam is not greater than 8 as qualified. Testing of the sampling rate of 5% of low-pressure, medium-pressure 20%, and low and medium-pressure system testing shall not be less than 1 system. System duct testing is appropriate to use segmented testing, summary analysis method. Tests found in the strip seam-shaped light leakage, depending on the system is unqualified, should be done to seal the treatment. If the bite seam leakage is serious, then re-production and installation of the section of the duct, and re-do the leakage test. (3) of the duct system leakage test, is to be measured duct system in a closed state, the use of special leakage test device source of wind into the system gradually increasing the amount of wind, so that the pressure in the system gradually rises to reach a predetermined value, to maintain its stability, then the amount of leakage of air in the system and the leakage test device to make up for the amount of air just to keep equal under the pressure. Read the air leakage test device to supply the system's air volume, that is, measured the system under a given test pressure air leakage, averaged over the area of the duct being tested, it will be derived from the system duct leakage per unit area, and the allowable air leakage for comparison, the test results can be qualified or not. (4) system air volume balance adjustment, the determination of air volume can be measured in the pipe, can also be used to measure the pipe mouth. System total air supply, return air volume and fresh air volume can be adjusted by adjusting the total air duct on the adjustment valve to adjust the air volume, until it reaches the design requirements, and the deviation from the design air volume should not be greater than 10%. The adjustment and balance of the air volume of the air outlet should generally take the base air outlet method and the flow rate of equal distribution method. General flow is more than the distribution method, is the most unfavorable loop (wind mouth) to start, so that the downstream loop measured air volume and upstream loop measured air volume and design air volume distribution ratio is consistent. Then, one by one, the upstream loop is adjusted so that the measured wind volume between each loop is consistent with the design wind volume allocation ratio. And so on, and finally adjust the fan at the damper, so that the system air volume in line with the design requirements. (5) duct air volume measurement, determination of the location should be as far as possible in a section of not less than 6 times the diameter of the duct on the straight section, the measurement of the cross-section as close as possible to the end of the 1.5 times the diameter of the duct, and there is room for maneuvering. Rectangular cross-section measurement point should be divided into a section of 200 ~ 250mm for the length of the small square section, the measurement point is located in the center of the small cross-section; circular cross-section measurement point will be divided into a circular cross-section of equal area of the 3 ~ 5 concentric rings, measurement of each ring on the horizontal and vertical direction of the four points, take the average of the measured wind speed for the wind velocity of the duct being measured. (6) the measurement of the air volume of the air outlet, the simplest way is to use the anemometer directly at the air outlet to measure the wind speed of each point, take the average value, and then according to the area of the air outlet to get the air volume of the air outlet. For the slit-shaped air outlet and louvered air outlet so that the test is feasible, such as diffusers and other structural forms of complex air flow conditions of various air outlets, with the method of measuring the air outlet air volume results are often inaccurate. We can use the auxiliary duct to measure according to the shape of the air outlet (national standard GB50243-2002 Appendix B clean room test method provides for air supply outlet air volume test method). General non-clean constant temperature and humidity system is not necessary if we do not use a specialized air flow measurement device (using the fan to compensate for the resistance of the device method).