A building operation specialist has asked your engineering f

A building operation specialist has asked your engineering firm to add a hot water control loop to an industrial office building that utilizes waste steam from a process in the company to save energy on heating water. The system is a simple closed loop system. Here is the diagram of the water control loop. For the final lab you are to design a system that will maintain a water temperature of 90 degrees. This will be a stepper system with the following parameters: When the TT reads below 80 degrees the steam valve will open 100% When the TT reads between 81-89 degrees the valve will be at 50% When the TT reads 90 or higher, the valve will shut completely The TC is a PLC and you will use a Thermocouple for the temperature primary element. You may choose to use either Fisher Valve in the lab.

Solution

This types of example is very much used in real world industry.

So it is good for you to understand the answer in deep.

So. lets talk about the answer of the quastion.

for the given quastion first you need:

(1)Servo motor with mechanical linked to valve for operating ON and CLOSE,

(2)Thermocouple for measuring the value of temperature in electrical form

Thermocople is one type of transduser wich convert temperature in to praposnal electrical value which is in mA or mV.

(3) For temperature controller used PLC or PID controller.

First, let me understand you that the temperature is measured by thermocople and what ever value is measured was feed to the PLC , and then plc give the command to the servomotor to operate either open or closed.

So for that we can make the close loop diagram like this.