Centrifugal compressor flow rate issues
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Our company uses centrifugal compressors to compress air. The compressors feature two stages with 6 compression stages each. As temperatures rise, the outlet flow rate decreases. We would like to increase the outlet flow rate by installing an axial flow fan at the inlet; I wonder if this is feasible. The compressor parameters are as follows: Inlet pressure: 0.0965 Mpa (the inlet is connected to the atmosphere); Outlet pressure: 0.9654 MPA; Inlet flow rate: 530 m/min
"Now that the temperature is rising, the export flow rate is decreasing. What is the reason for this? It’s necessary to analyze the situation thoroughly before taking any actions. What you suggest seems unworkable; your approach is aimed at addressing issues related to insufficient inlet flow. Clean the inlet filter or replace the filter element, and check whether the inter-stage cooling is functioning properly – clean the inter-stage coolers as well.
Thanks to the person above. The inlet filter and interstage cooler have been cleaned; they were just cleaned. But it doesn’t have much effect. Are there any good ways to increase traffic?
1 Ignoring mechanical factors, what affects the compressor’s flow rate is closely related to the density of the air, and density is associated with temperature, humidity, and pressure. 2 Therefore, measures should be taken by considering these factors. 3 For example: implementing cooling measures at the inlet, adding desiccants, increasing pressure, etc； The filtering area of the inlet filter can also be increased to reduce the pressure drop. Therefore, using a ventilator to increase pressure is a practical solution; the required increase in pressure to compensate for the rise in temperature can be estimated using the gas equation, thereby allowing for the selection of an appropriate ventilator. Since the outlet pressure of the ventilator is very low, and it is possible to adjust it to the desired inlet pressure, its impact on the centrifugal compressor is not significant
The temperature of the cooling water can be reduced or its flow rate increased in order to lower the air temperature
May I ask the expert on the 4th floor: 1, where is the best location to install the fan, before or after the filtration? 2. How to calculate fan flow and pressure
May I ask the expert on the 4th floor: 1, where is the best location to install the fan, before or after the filtration? 2. How to calculate fan flow and pressure
1. It is better to install the fan before filtration. 2. The flow rate of the fan should be chosen based on the maximum flow rate of the compressor or the desired flow rate; the pressure should be set according to the desired increase in pressure (it shouldn’t be too high, as the fan’s power and the performance of the centrifuge need to be taken into account). Fans are now standardized; one can simply choose those made by manufacturers that produce ammonia-related fans. Of course, custom-made fans may offer better energy efficiency ； 3. Adding a water scrubber at the inlet or improving the cooling effect is also an option.
To address this issue, it is first necessary to identify its root cause – what is the fundamental reason for the decline in traffic? A decrease in flow rate may be due to insufficient suction capacity of the compressor or problems with the drive side. Or, when selecting the machine, an inappropriate choice is made, and the operating point is not optimal, making stable operation difficult.