Seek a temperature control scheme for polymerization reactors
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Our company currently has a polymerization reactor, and it is required that the temperature during the reaction process be maintained within the range of 50–60 degrees. The main control parameter is the temperature inside the reactor, and control is achieved by using control valves for hot water and circulating water; a PID regulator is intended to be used for this purpose. We are looking for an effective solution
Series control of temperature and flow rate can be employed. The output is controlled in stages, with separate control for hot water and circulating water
The AI808 artificial intelligence regulator can be used to achieve this conveniently
We employ cascade control of temperature and flow rate
If possible, it is best to adopt a scheme using heat transfer oil in a jacket; the temperature of the heat transfer oil inlet can be controlled by separating hot and cold water. A cascade control scheme based on temperature differences or a cascade control scheme based on temperature and pressure can also be used, as pressure leads temperature by a significant margin – pressure is essentially an indicator of temperature. In fact, there are already well-established control schemes for polymerization reactions
Create a PID controller with feedback and proportional-integral control for two control valves: the valve controlling the circulating water cooling is regulated between 0 and 50, while the valve controlling the hot water is regulated between 50 and 100; at 50, both control valves are fully closed. In this way, the circulating water control valve is selected as air-shut, while the hot water control valve is selected as air-open.
I’m not sure what the process is; hot water is used in the initial stage, cold water in the middle stage, and a little hot water in the later stage – is that it? If so, a combined program with feedforward compensation control can be used; if conditions permit, temperature prediction control can also be added.
It adopts a split-control scheme: victory:
If PP is produced by batch liquid-phase polymerization, I agree with the plan proposed on the 5th floor. It’s a very old technique, though. I’ve seen it used that way. In the pure liquid-phase C3 (propylene, with a small amount of propane) regime, there is a certain relationship between temperature and pressure in the polymerization reactor; controlling the pressure is essentially equivalent to controlling the temperature. The temperature responds slowly, with a delay. The output is the division of steps.