Control scheme for the superheated water closed-loop system in the reaction kettle
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The reaction vessel aims to use a closed-loop system with superheated water and cold water to control the reaction temperature; the temperature needs to reach 140°C during the heating phase. How should a reasonable control scheme be designed?
A closed-loop system is designed to control the temperature of the reactor, with the core goal being to achieve precise control and rapid response. The following is a basic control scheme: 1. **Temperature sensor**: Install a temperature sensor inside the reaction vessel to monitor the temperature in real time. 2. **Controller**: A programmable logic controller (PLC) or thermostat is used to process the data collected by the sensors, and to control heating and cooling in accordance with the set temperature profile. 3. **Heating system**: Superheated water is heated using electric heating or steam heating, and a pump is used to circulate the hot water to the reaction vessel. 4. **Cooling system**: Cooling water is generated using cooling towers or chiller units, and it is circulated to the reaction vessel through another pumping system. 5. **Flow control**: Valves are used in hot and cold water circulation systems to control flow, and by adjusting this flow, precise temperature control is achieved. 6. **Feedback control**: A PID control loop is established to automatically adjust the ratio of heating and cooling flow rates based on the deviation between the actual temperature of the reactor and the set temperature, thereby achieving temperature control. It is recommended to carry out professional design and simulation testing to ensure the system’s stability and reliability. Safety measures must also be taken into account, including temperature overload alarms, pressure relief, and emergency shutdown devices. .
For cooling with cold water: Cold water is introduced at the pump inlet, and the temperature at the pump outlet is controlled by adjusting the flow rate of the cold water supplied. For superheated water: The superheated water is introduced at the pump outlet, followed by a pipe mixer; the temperature at the outlet of the mixer is controlled by adjusting the flow rate of the superheated water supplied. It mainly depends on the superheat; if vaporization does not occur after pressure reduction, it can also be added at the pump inlet. This is determined by the pressure in the closed-loop circuit and the pressure at the pump inlet.
Okay, thank you! If it is desired to keep the temperature difference low during the reaction process, would it be feasible to control the temperature by mixing two streams of water and regulating the temperature at the outlet of the mixer?