Temperature control system and its application.
Introduction:
What is a temperature control loop?It is something that can
alter the temperature of a room or even in industries where the need to cool
down the temperature or heat it up.
Many people like ice-creams,in making of
ice-creams the temperature of the candy needs to be brought down to keep it
from melting and how that is done well see.
The other applications.We will
also see how the
temperature is controled in the nuclear power plant(RBMK reactor).
How is the temperature maintained?
So the candies are passed through the freezer where it is placed
into blast freezer at -30° to -40° C where most of the remainder of the water
is frozen. Below about -25° C, ice cream is stable for indefinite periods
without danger of ice crystal growth; however, above this temperature, ice
crystal growth is possible and the rate of crystal growth is dependant upon the
temperature of storage.
While packing Method of stacking containers or bundles
to allow air circulation. Circulation should not be impeded - there should be
no 'dead air' spaces (e.g., round vs. square packages).
●
Care of evaporator - freedom from frost - acts as insulator.
●
Package type, should not impede heat transfer -
e.g., styrofoam liner or corrugated cardboard may protect against heat shock
after hardening, but reduces heat transfer during freezing so not feasible.
So the temperature is maintained so that the ice-cream does not
melt.
How does an RBMK reactor works?
The RBMK nuclear
reactor is a soviet-designed reactor dating back a few decades in design. There
were almost twenty of these reactors completed, and 11 of these reactors are
still in use in Russia.
This reactor type is rather infamous because
of the Chernobyl accident, the Chernobyl-4 reactor which melted down was of the
RBMK design. All of the RBMK reactors in current use are retrofitted from the
original specifications.
As we all know nuclear power plants are used to
generate electricity. To generate electricity we use uranium-235.
So heat is generated by splitting U-235
atoms and to control the temperature we run cool water through the core.When
water is rushed into the core it turns it into steam and and that steam is
passed to the turbine to generate electricity.
To control the reactivity boron control
rods are used.To stabilize this system positive void coefficient is used and
more heat is produced and also more steam is produced.
To counter that part negative void
coefficient is used to control the reactivity and to control the heating of the
nuclear fuel.
If the nuclear power plant is neatly operated then this is a beautiful
process.The chernobyl power plant used RBMK reactor and used to power the whole
ukraine.
