1. 1
NEED OF CONTROL: -
Boiler tubes will be puncture if temperature of steam increases.
So, temperature of steam should be maintained and controlled.
Increase in pressure and flow of steams increases the speed in
rotation in turbine shaft which cause a great damage to the
Turbine and Generator. So, pressure and flow of steam should
be maintained and controlled.
On the boiler drum 50% of water and 50% of steam is
present, Increase in % of steam in boiler drum increases the
pressure in it of pressure in drum increase the drum may blast.
So, the level of steam should be monitored and controlled.
If RPM in turbine increases the blades present in the turbine may
damage. So, RPM of turbine should be controlled.
For pure water pH value is 7. If it is less than 7 the water is said
to be acidic in nature. If it is greater than 7 the water is said to
be basic in nature.
Acidic water corrodes the Boiler tubes. Basic water forms
coagulations when it is heated. If coagulated steam falls on
turbine blades cause damage to blades and produce vibrations
in turbine. So, pH value should be measured and controlled.
Vibration in Turbine and voltage given to the auxiliary
motors should be measured for operation and maintenance
purpose.
2. 2
TEMPERATURE SENSOR: -
The measurement of temperature is one of the fundamental
requirement for environmental control as well as certain electrical and
mechanical control.
Many different type of sensors are commercially available and
the type of temperature sensor that will be used in particular
application will depends upon several factors eg. Cost, Space,
Durability, Accuracy.
Temperature Measuring part Types of
Sensor/Instruments
Range (°∁)
a. At Super Heater Thermocouple 600° − 700℃
b. At Boiler Thermocouple 520° − 600℃
c. Economizer
Condenser
RTD ( Resistance Temp
Detector)
20° − 80℃
PRESSURE SENSOR: -
Pressure sensor is uses to measure the pressure in the steam
boiler. It measures the amount of force applied on a unit area.
In the plant pressure has a very big role. So we use BMP180 high
precision Digital Barometric Pressure Sensor.
Pressure Measuring Points Types of Sensor Range
a. Boiler Turbine Bourdon Tube 6.89 – 2063.4 kPa
b. Condenser Bourdon Tube 2 – 7 kPa
3. 3
On these days BMP180 also used
→ Pressure Range : 300 – 1100kPa ( Elevation 500m – 900m)
→ Power supply voltage : 1.3V – 3.6V
→ Size : 3.6mmX3.3mmx0.95mm
→ Low Power Consumption
→ High Accuracy
→ Low Power mode
LEVEL SENSOR: -
Level sensors detect the level of substances that flow, that
including liquids, slurries, granules materials and powders. All such
substances flow to become essentially level in their containers (or
other physical boundaries) because of gravity.
The substances to be measured can be inside a container or can
be in its natural form (eg. A river or a lake)
Hence we used level sensor in
a. Boiler drum
b. Condensate tank
c. Water line
FLOW SENSOR: -
Flow sensor used to measure the flow of steam from boiler to
the turbine.
Here we used a rotor flow sensor.
Flow range 1LPM to 227LPM
4. 4
RPM SENSOR: -
RPM sensor is used to measure the no. of rotation that a turbine
shaft will rotate per minute.
AM4096 sensor which provides absolute positional information
output to an accuracy of better than 0.1 degree.