I really can’t understand it; I hope someone experienced can give me some guidance
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I really can’t understand it; I hope someone experienced can give me some guidance
If I were the client, I would send the drawings back to him and have them redone in accordance with the standards.
1. This circuit diagram is not standard; it doesn’t look like something produced by a design institute, but rather like a diagram made by a manufacturer of complete equipment sets； 2. Several points the above diagram aims to convey: A. The flow meter’s range is 0–450 m3/h; B. The low flow alarm threshold is 90 m3/h ； C、High flow alarm: 350 m3/h ； D. Set value of the flow control circuit: 320 m3/h ； E. 30 seconds before pump startup, the system forces the control valve to the fully open position (override) ； Controllable after 30 seconds.
There is indeed a problem with this diagram, but you are right. I think this is the part of the diagram that raises the most objections – how could it be fully turned on? To me, it seems to be fully turned off……
I understand a bit now, but I’m still not quite clear about the 30-second full-on setting. Could an expert please take another look at this diagram?
I understand a bit now, but I’m still not quite clear about the 30-second full-on setting. Could an expert please take another look at this diagram?
It seems to me that everything will turn off after 30 seconds.
I don’t see what there is to not understand. The top two columns are high alarm and low alarm; they are just comparison blocks ； The third column represents PID control; the set value is 320, and it is a gas-shut valve. Therefore, when k=0, the valve is fully open. In China, this is generally not done in this way; if I were to do it, it would output the inverse value ； The fourth column represents a 30-second delay; there is a switch connected to the PID block that sets k to 0. What were those words again? So easy!
Why is the valve fully open when K is 0? Shouldn’t it be turned off completely?
Didn’t you see that the valve’s fault status is FO, which means it’s a gas-shut off valve? Didn’t you study control systems?