Overcoming pressure fluctuations downstream of the pressure control valve
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Question: Guys, a control valve has been installed on the air pipeline (for single-loop control by a controller) to keep the pressure downstream of the valve at P1. However, since the amount of air used downstream of the control valve varies greatly, the control effect of this valve is poor, resulting in significant pressure fluctuations. Are there any measures that can be taken to improve or overcome the pressure fluctuations caused by this traffic? My suggestion: Add a pressure buffer tank behind the control valve. Please give me your help.
When the demand for air at the downstream end fluctuates significantly, installing an air buffer tank is one solution. The pressure in the buffer tank remains relatively stable. But what is the load?
In general, in such cases, a buffer tank is added first, which makes it easier to control the pressure
Wouldn’t it be more effective to just use a self-acting pressure relief valve?
It supports the above statement: when the pressure before the valve is constant, the pressure behind the self-acting pressure control valve also remains essentially at the set value, unaffected by the load.
I agree that efforts should be made in terms of process optimization; the impact of using instrumentation solutions on solving problems is limited!
Reply to 2# yhong: Hello, I’m working on the fuel gas pipeline, and the load is a turbine generator. This is because changes in the load on the generator are reflected as changes in the flow rate of fuel gas consumed. Adding a buffer tank is undoubtedly one method; I wonder what can be done from an instrumentation perspective? For example, equipping it with more precise valves? Equipped with a valve positioner? Please let those on the 2nd floor and all enthusiastic comrades share their views. Thank you to all who responded!
Specify the range of flow fluctuations, and then consider whether the diameter of the control valve is appropriate, or there are issues with the parameter tuning of the control system. The selection of the valve port size and regulator parameters has a significant impact on the stability of control.
I think it’s more reasonable to install a buffer tank.