Design of an automatic control system for a shell-and-tube heat exchanger

This study investigates the design and implementation of an automated control system for a laboratory-scale shell-and-tube heat exchanger. The primary objective was to stabilize the outlet temperature of the hot stream by automatically regulating the cold-stream flow rate. The research involved hardware modifications, including the integration of a DC flow pump and an upgraded temperature measurement system using DS18B20 digital sensors. A control and monitoring interface was developed using SerialCom Instrument software and connected to an Arduino Mega 2560 microcontroller. A proportional–integral–derivative (PID) feedback controller was designed and optimized through the Ziegler-Nichols method, MATLAB Simulink simulations, and trial-and-error experiments. The results demonstrate that the system operated stably, with the optimized PID parameters enabling the outlet temperature to closely track the setpoint with a very low error of 0.12%. The actual heat transfer efficiency reached approximately 65%, indicating the effectiveness of the proposed automated control system.