CONTROL AND INSTRUMENTATION OF THERMAL POWER STATION - PART -I

Till date we have discussed all the aspects of  thermal power station starting from civil construction , equipment erection and commissioning of the system. From this dispatch we will touch up on the importance of instrumentation and controls in thermal power station.

Instrumentation can be divided in two major Groups.

A ) Primary Instruments ( like pressure gauge , Pressure Transmitters , Temperature gauges and temperature Transmitters , RTDs , Thermocouples , Vibration measurement , Analysers , position transmitters , Limit switches , Level switches and transmitters ,Pressure Switches , Temperature switches , Differential Pressure Transmitters , Different type of isolating valves according to process requirement  etc. 

There are other primary instruments also but the list given above is most widely used in thermal power plant and any other process plant.

B) Secondary Instruments  ( like recorders , printers , digital indicator , Computer , Monitor , Digital control panel , Temperature Scanner , data logger , Analogue  and digital Control system , Different type of control panel of  specific use like DCS , Soot Blower , Auxiliary PRDS , Drum level measurement , Turbo visory system including speed and vibration measurement . etc. Secondary instrument gets signal from primary instruments then  processed and  presented as per our requirement.

Instruments can also be  grouped in the following manner 

i) Mechanical Instruments 

ii) Electrical Instruments 

iii) Electronic instruments

iv) Hydraulic Instruments. ( vane control etc )

v) Pneumatic  Instruments ( like Power cylinders, Control valves ,

e/p converters etc.

continued to PART _II