Why condenser is needed in steam power plant?

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  • In a steam power plant, turbines operates with the help of high pressure steam which is generated in a boiler.
  • Before reaching the turbine blade it passes through a HP compressor, IM compressor then a LP compressor.
  • In this process, pressure energy of the steam is converted to the kinetic energy.
  • After passing through the turbine pressure of the steam decreases.
  • In-order to have a high pressure steam we have to condense the steam to water and again the cycle repeats. For this purpose condenser is used in steam power plants.

After the steam expanded in turbine and when it leaves the turbine the steam passes through the condenser in order to cool to its liquid state. In condenser the steam will be cooled to its liquid state at constant temperature and pressure. Only entropy change will takes place. i.e phase change takes place.

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The advantage of the condesor is to reduce the temperture of the steam in order to make all the steam into liquid water. The pump can compress only one phase of any liquid or gas. It can not compress the liquid in wet region of the t-s diagramme.


  • Dec 19th, 2010

In power plant the the low pressure steam leaves the turbine should be condensed due to following reason.

The turbine output will increase if we decrease the turbine  out steam pressure. lowering of pressure is possible by applying vacuum in the outlet of turbine. but to extract the huge quantity of steam a high capacity vacuum system is required,it will increase the capital cost and operating cost. so to reduce the vapour load on vacuum system, condenser will be will condense almost all vapour load so the vapour load on vacuum system will be low. at high vacuum turbine outlet temperature and pressure decreases, in turn turbine output(efficiency) increases.  the condensed water is directly pumping to boiler for recycle.

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  • Aug 7th, 2011

after steam expanded from turbine, it condenses into liquid state and feed pump will convey the water in boiler
condenser is needed because feed pump can not operate with steam so it needs to convert steam into liquid state so that pump can convey the liquid to boiler easily.

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  • May 21st, 2012

Basic Reason behind using condenser in the steam power plant is simply reducing the pressure of steam below atmospheric pressure,which helps in increasing area of P-V diagram.......that simply means increment of output power from the it helps in increasing output along with efficiency of plant...

nrj yadav

  • May 23rd, 2012

Condenser is placed before the compressor so as to convert the steam into liquid form , because steam would have required more work for compression than liquid . so we convert the steam into liquid in condenser to reduce compressors work .

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ahmed mahmoud

  • May 24th, 2012

The pressure at the end of turbine exit is low and the temperature is relatively high so the state of water (saturated or in wet region ) the pump compress only in incompressible fluids like water and dont compress vapor or (vapor + liquid water ) so it must be completely water

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  • May 26th, 2012

first there is no compressor in steam power plant as compressor can be used only to compress gas not liquid.

condenser is used in plant to condense the steam so that liquid water can be pumped to boiler for steam generation now one may think why bother to add condenser and waste heat energy in form of latent heat just transfer the steam of low pressure to boiler but one must remember that to generate work from any heat engine we have to transfer some of the energy in heat sink


  • Sep 19th, 2012

Much easier to transfer liquid water through pumping then it is to transfer as steam back to the fired heater. Usually some duty is recovered by crossing the turbine discharge with the inlet water to the fired heater.

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  • Feb 15th, 2013

In order to decrease steam pressure below atmospheric so that output can be increased

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Bilal Shabbir

  • Feb 25th, 2013

To prevent loss of water which was treated in demin plant , the condenser recycle this water into make up of boiler again

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  • Mar 22nd, 2013

Condenser changes vapour to liquid phase at constant pressure because pumping of vapour is not possible by pump.

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Mahesh Patnala

  • May 16th, 2013

Condenser improves P.Plant performance by reducing the pressure(due to change in phase i.e gas to liquid) at outlet of turbine.


  • Aug 8th, 2013

As per second law of thermodynamics (Kelvin Plank) it is impossible to produce work if device has only one thermal reservoir i.e. boiler so we need another reservoir i.e. condensor to complete the cycle and to produce work

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  • Mar 7th, 2015

The high pressure steam after getting expanded at the turbine its dryness fraction decreases. This becomes extremely difficult for a pump to send it to the boiler boiler at high pressure. It is easy to pump a liquid rather den a mixture of steam and water. It can be achieved but very very expensive. Therefore condensor is used to change the phase of the steam to water

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  • Mar 29th, 2015

The presence of condenser creates partial vacuum (0.01 bar) Which provides greater enthalpy drop in the turbine ie, increased work done. Also, if steam has to be directly transferred to the boiler enormous amount of work has to be done as the specific volume of steam is more (work done is 300 to 500 times more). Also, if pumped at near saturated condition partial condensation will take place in the pump. The presence of two phase in the pump will cause uneven pressure that will brake the impeller.

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Kamesh Awasthi

  • Apr 2nd, 2015

A condenser while condensing creates high vacuum [ Water Vapour is acquires 63 times more volume than water vapour]. This vacuum provides a draft for the steam to flow from Boiler towards condenser and moreover we need to Save water[Power plants use demineralized water, and demineralization is a costly affair] and reuse it.
Save Paper, Save Earth

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  • May 31st, 2015

According to second law of thermodynamics some amount of the heat should be rejected in the cyclic process its very necessary.....
now we will talk about why is it necessary?
Its complete the expansion of the steam at lower pressure that gives more work so we will get high efficiency.

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bhoopendra chouhan

  • Jun 5th, 2015

Specific volume of steam is very large if we fed this steam directly in to the boiler we have to do equal amount of work which we are getting from turbine expansion (actually more due to friction and other losses). so first we condensed it up to liquid saturation line

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  • Oct 23rd, 2015

Condenser is used to condense the exhaust steam for turbine

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pawan prajapat

  • Jan 29th, 2016

Condenser is a device which condenses hot steam which discharged from the IP turbine blades. When the hot steam comes in to the condenser from the turbine, it converts steam in to the hot water. This hot water go to the cooling tower for cooling and again after purification of water go in to the boiler drum. Hence the condenser is a very important device in thermal power plant for condensing the steam in to the water.

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  • Feb 17th, 2016

In steam power plant pump can compress only one type of phase either liquids or gases. Work done required to pump is directly proportional to volume of fluid has to compressed as we know that specific volume of water is less than specific volume of steam so to reduced pump work we used condenser

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ramani hardik

  • Feb 23rd, 2016

Condenser is need to condense the water which is at outlet into turbine. So we can use same water continuously and it does not need large amount of water.

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Akshat Srivastava

  • Aug 8th, 2017

To lower condenser temperature its overall efficiency increases

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  • Oct 22nd, 2017

Thermodynamics is a process in which energy is transferred in the form of work and head in equilibrium condition.

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  • Oct 22nd, 2017

To decrease the temperature and comes to its original temperature before its inlet in turbine. If its temperature is not decreased its efficiency gets low, so finally condenser is used to increase the efficiency.

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