How to prevent the valve from opening fully
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I’m new to this field, and there’s one thing I don’t quite understand. Could everyone please help explain it: when the ratio of oxygen to water vapor is high, the oxygen flow control valve should not be opened further.
More oxygen is added, a spark enters, peng~
Typical PID controllers have the capability to limit the maximum opening degree of the valve; for example, the LMN_HLM pin of Siemens’ CTL_PID module, and the OPHILM pin of HONEYWELL. When the ratio of oxygen to water vapor is high, a certain value can be generated using a specific formula and sent to these pins, thereby preventing the valve from opening too far.
Interlock functions are generally used to limit the opening degree of the control valve when certain conditions are met. This ensures that the valve will not open wider or narrower
This post was last edited by khhzh116 on 2016-3-30 08:21. I. Which DCS? Answer: Any company should be able to do it, right! Besides, the DCS has not been selected yet; I myself don’t know which brand to use II. What functions do you want to implement? Answer: As stated in the question, under normal conditions, oxygen is automatically adjusted in proportion to water vapor according to the set ratio. In case of a fault and this ratio is exceeded, the oxygen valve is prevented from opening further. Is there anything else you don’t understand? Oxygen-to-water vapor ratio control loop for gasifiers
With no significant change in the amount of water vapor, further opening the oxygen valve will increase the already high ratio of oxygen to water vapor, making the situation even worse; this is why it is prohibited to open the oxygen valve further
Water vapor or oxygen can be used as reference values, and by establishing a proportionality relationship, the control valve can automatically regulate the flow rate of the other medium, thereby avoiding any issues related to proportional imbalance~~
This can be achieved by limiting the PID output.
Any brand of DCS system can easily solve this problem!
PLCs can handle all of this…… First, make a comparison; if the result is less than a certain value, output an appropriate value. , if it is greater, output 1, so that the next block outputs the given value