A certain unit has an air-conditioning system in operation, and the air supply pipeline generates surge, and the tuyere connected to the air supply pipeline also surges with it. After inspection, the vibration damping support of the fan is reasonable, and the hose head connected to the air supply pipe at the outlet of the fan is also intact. The opening degree of the circular flap start valve at the fan inlet is at the maximum position (the opening degree of the circular flap start valve at the original fan inlet is about 60%).

According to the analysis of the situation on site, it is believed that the fan selected in the air-conditioning system is too large, and the air volume and pressure generated by the fan during operation do not match the system. When the air volume balance of the air-conditioning system is carried out, it is adjusted according to the design air supply volume of each air-conditioned room and each air supply outlet. However, due to the change of the valve position, the opening degree increased, so that the fan was working in a state of large air volume and high pressure head (compared with the original circular flap-type start valve at the entrance of the fan), and at the same time the fan was made to work. The static pressure in a section of the air duct from the outlet to the air volume control valve above each air supply branch pipe increases, but the air volume control valve on each air supply branch pipe (still maintains the original opening position of the air volume control valve) is throttled to form a jet of air flow. The static pressure in the pipe section behind the air volume regulating valve on the branch pipe drops sharply, and the airflow speed increases sharply, thus causing the surge phenomenon of the air supply pipe.

According to the above situation, the processing methods when such a fault occurs are as follows:

2.1. Replace the pulley of the fan, reduce the fan speed, and move the performance curve of the fan downward, so that the air volume and air pressure generated by the fan operation match the air conditioning system;

2.2. Use the circular flap start valve at the fan inlet to change the working point of the fan, so that the air volume and air pressure generated when the fan is running at the new working point match the air volume and air pressure required by the air conditioning system to meet the needs of the air conditioning system. actual needs;

2.3. Replace the appropriate fan.

Suzhou Pharma Machinery Co.,Ltd.

2022/09/14

Birkey