Why do we need a condenser in thermal power plant or Rankine cycle?

In a Rankine cycle, the liquid water is superheated in the boiler. The superheated steam is further expanded in the turbine. From the turbine exit the steam is sent to the condenser for condensation and after condensation, the liquid water is sent to the boiler again.In the condenser, the steam rejects heat to the surrounding. A question appears in mind i.e., why do not the steam is heated in the boiler just after exiting from the turbine? Why condensation of steam is required? If not condensed then It will save the heat from being lost to the environment.This lecture answers it with easy understanding....

[@krishnavamsi600]

U totally understand students minds . explanation and diagrams ❤️

[@anilkumar-pc3cx]

At point 4 water is in liquid state it happens in economiser only while in boiler water exists in both liquid and vapour state which is being shown by straight line inside the curve.Hope it helps

[@anilkumar-pc3cx]

Also as per second law of thermodynamics. We cannot have work output without heat sink. That is the case of perpetual motion machine of second kind.😊

[@deepaksahoo1338]

Thank you so much Sir 🙏🙏

[@Anilskapkoti]

Why we are not using a compressor instead of condenser.

[@alialmutairi7809]

thank you

[@rohitbhosle6521]

Great video 👍😊
1) What if we throw that low pressure steam in ambient lake and take water from lake with pump (similar to open brayton cycle ) so this will eliminate use of condensor ...if this works then how it's compare to actual rankine cycle
2) what if we collect low pressure steam and collect in closed vessel with no return valve and we heat steam upto boiler pressure in constant volume process ..so eliminating both pump and condensor (I know this is not going to work but I wanted to know proper explation just like it's violets 2nd law by doing so and so or practical explanation like Wout will not be continuous but intermittent etc )
It would be really nice and helpful if anybody can help 😃

[@Dr.AmitMandal]

1) Low pr steam will not dispense in Lake , Lake wate will rush inside the turbine, only condesation in condenser can pull the water inside. Coz ambient pr is 1atm, greater than the condensing steam.
2) Collecting low pr steam in vessel and pumping is unnecessary pumping, waste of power, condesation does the same job without any cost...

[@Doesit_matter]

Superb sir❤️

[@shivasmart967]

tq sir

[@MECHANICAL_BUDDY]

Sir after expanding in the turbine,if we sent that fluid to the boiler through pump the pressure will rise na sir !!?
Then where is the possibility of pressure being less than atm pressure ??

[@dilsadansari5843]

the output of the turbine is in the form of wet steam, since pump can only pressurize liquids it cant pressurize the steam in vapour state. Thats why we use condensers so that by rejection of latent heat from the steam it can be brought to liquid state.

[@abdullah-al-faruk8915]

Pump cannot use steam as working fluid.for this steam must be condensed into liquid state

[@fariesmech]

Wet steam or superheated vapour are not allowed inside the pump as it leads to cavitation. This might be reason.
Other reason is, pumping wet steam or superheated vapour requires more work done which leads to decrease in efficiency.

[@sindhusindhuja6745]

We are getting exhausted steam, not fluid from the turbine, steam has to be converted into water, so condensor Is used, to reuse the water again, we use pump to increase its pressure,

[@tanvirahmadhashmi3558]

Please elaborate this sentence "In condenser, the pressure of condensing steam cannot be less than saturation pressure of environment."

[@Dr.AmitMandal]

The minimum temperature of condenser is the environmental temp becoz it looses heat to environment and heat always flow from high to low temp body. Thus the minimum pressure of condensing steam will be saturation pressure of environment temp as the condensing steam's temp is equal to environmental temp...

[@kshitijvermacms]

@@Dr.AmitMandal thanks

[@MVBSHADABARSHAD]

Effective contents 🤗
But one equation in mind
Why we can't use compressor to increase the pressure of steam directly after expansion form the turbine ?
Can we use or not in power plant ?

[@Dr.AmitMandal]

Compressor means input of work, however goal is to derive work...

[@Shubham-he4xr]

Why can't we just use pump after expansion through turbine to increase the pressure?

[@Dr.AmitMandal]

The actual pump does the same job you are asking

[@arujsinghai247]

Pump can't use steam as working fluid for pump we need liquid state only