DESIGN, SIMULATION AND HARDWARE IMPLEMENTATION OF AUTOMATIC INDUSTRIAL TEMPERATURE CONTROLLER ON EMBEDDED PLATFORM

Abstract

Automatic industrial temperature controller is an integral and one of the critical components of an Industrial Process heating. One such industrial process is food sterilization process[25] where it is required to Heat the process fluid at specific sterilization temperature, maintain this temperature for the process duration, on completion of process; the process fluid is to be cooled down. In such industrial process heating system, the controller maintains the temperature of fluid under consideration at a specified value during the entire process duration. If the current temperature of the fluid falls below the specified value an Electric heating element is required to be switched ON, so that the current temperature can be brought within specified limit. After the sterilization process is over it is desired to cool the process fluid, for this a cooling arrangement is required to be switched ON so that the current temperature can again be brought down to new specified limit i.e. new desired temperature. Thus the intended purpose of automatic industrial temperature controller for sterilization process of food product is achieved by a combination of heating system in conjunction with a cooling arrangement. This Dissertation proposes to design, simulate and physically implement a microcontroller based Industrial Process temperature control system which will control and optimize the power input to heating system when the temperature deviates below the set temperature. If the desired temperature requirement falls below the present level, the same controller will control and optimize the power input to a variable speed DC motor based cooling system, which will cool the process fluid till the new desired temperature is achieved. The proposed controller will switch, optimize and control the power to two in no heating element based on temperature requirement if needed, the Pulse-Width Modulation based speed controller will be implemented so that cooling pressure depending on the quantum of temperature variation is achieved The average value of power fed to the cooling pump motor is controlled by duty cycle of the PWM signal, this is achieved by a solid-state switching circuit. The longer the switch is on compared to the off periods, the higher the power supplied to the load i.e. higher the cooling.