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Thermodynamics

Why condenser is needed in steam power plant?
Asked by: deemech | Member Since Nov-2009 | Asked on: Jul 11th, 2010

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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.

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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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dr_omega2007

Answered On : Sep 9th, 2010

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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.

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sudeeb

Answered On : Dec 19th, 2010

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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 use.it 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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dhaval

Answered On : 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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PAWAN SINGH

Answered On : 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 cycle........so it helps in increasing output along with efficiency of plant...

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nrj yadav

Answered On : 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

Answered On : 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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quwer

Answered On : 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

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RyanCHE

Answered On : 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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achyuth

Answered On : Feb 15th, 2013

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

  
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Bilal Shabbir

Answered On : 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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jayakrishna

Answered On : 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

Answered On : 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.

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Prateek

Answered On : 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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