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Showing posts with label How it works?. Show all posts
Showing posts with label How it works?. Show all posts

Why overall efficiency of thermal power plant is very low?

Are you wondering why overall efficiency of thermal power plant is very low? Reason?

The major part of the electricity that world is producing nowadays comes from Thermal Power Plant (which works on Rankine Cycle or Modified Rankine Cycle).

The principal parts of the Thermal Power Plants are

  • Boiler (to generate steam from water)
  • Turbine (where the steam expands and produces the work in form of rotation of shaft which in turn rotate the generator)
  • Condenser (where major part of heat is rejected to convert steam into water for reuse)
  • Feed Pump (to pump back the feed water to boiler for steam conversion) 
All parts except the condenser have 80 % to 90 % efficiency. The only condenser has 50% efficiency. 

Overall Efficiency: Multiplication of all efficiency of plant's principal parts
Thus overall efficiency comes down to 30 % - 40 %

What will be the change in room temperature if door of refrigerator kept open?

What will be the change in room temperature if door of refrigerator kept open? This question is often asked at mechanical engineering job interview and also in engineering examination.

Ans: NO, Rather, temperature of the room will increase over the time, not instantly.

Why?

To understand this, let us first understand the working of domestic refrigerator. It contains four different equipment namely compressor, condenser, capillary tube and evaporator and it also has refrigerant or working fluid/medium which continuously circulating through all these four different equipment to enable heat transfer and thus cooling. The refrigerant while passing through different parts, changes phase and this enable cooling in domestic refrigerator.

Refrigeration system-Construction and working of 'Ice plant'

We all are aware of domestic refrigerator and its usage. We get ice cubes from freezer compartment to meet daily requirements but to get ice in huge quantity we normally approaches the ice plant or factory. Here, I am going to share overview of construction and working of ice making process and its layout. 

Normally, any refrigeration system consists of four main equipments:

1. Compressor
2. Condenser
3. Throttle valve/flow control valve
4. Evaporator

Construction of Ice plant
But in Ice plant or factory, two additional circuits help us to create ice in huge quantity. Refer to the figure and Video.