Any way to prevent condensation of steam to water at low temperatures (26-29 degrees)

Replies

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  ISHAN TOPRE

  PrinceTan

  can we alter the compositions of the steam mixture to prevent it at 26-29 degree Celsius?

  What does it mean? Please post in detail.
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  Ramani Aswath

  PrinceTan

  Greetings,
  Like can we alter the compositions of the steam mixture to prevent it at 26-29 degree Celsius?

  The saturated vapour pressure of water at 26C=0.0336 bar and at 29C = 0.0401 bar. If your concentration of steam is less than this in your mixture it will not condense.
• 

  PrinceTan

  Issue

  What does it mean? Please post in detail.

  meaning I wanted to prevent condensation of water vapor from happening even at low surrounding temperature to drive a turbine to produce electricity. And since the surrounding temperature will be around 26-29 degree Celsius, normal water vapor would have condensed back into water rendering it unable to turn the turbine, so I wonder if there is any way we can prevent condensation even at low temperature without affecting the energy level within the water vapor..
• 

  PrinceTan

  bioramani

  The saturated vapour pressure of water at 26C=0.0336 bar and at 29C = 0.0401 bar. If your concentration of steam is less than this in your mixture it will not condense.

  Are you suggesting that if we can somehow maintain a pressure of 0.0401 bar within the concealing vessel where the steam is then we can prevent the steam from condensing even at 29 degree Celsius? Will it affect the heat energy level within the steam so that it can still turn a turbine to generate electricity? It shouldn't be affected should it?
• 

  ISHAN TOPRE

  PrinceTan

  meaning I wanted to prevent condensation of water vapor from happening even at low surrounding temperature to drive a turbine to produce electricity. And since the surrounding temperature will be around 26-29 degree Celsius, normal water vapor would have condensed back into water rendering it unable to turn the turbine, so I wonder if there is any way we can prevent condensation even at low temperature without affecting the energy level within the water vapor..

  Well yes. If that is what you are saying, go by what Ramani sir said. At pressures as low as 0.0401 bar, you would be able to maintain water in superheated conditions at 29 Deg C. 😀 Just refer the normal Temperature Entropy curve for water!
• 

  CE Designer

  Wow, interesting topic, but im kinda lost here. Ramani/Issue can you explain the foundation based on what you are saying?
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  ISHAN TOPRE

  CE Designer

  Wow, interesting topic, but im kinda lost here. Ramani/Issue can you explain the foundation based on what you are saying?

  It is actually simple. Suppose water vapor is held in a superheated condition at a higher pressure and at a higher temperature (P1, T1). Now we want the water to be at lower temperature, so the pressure is also lower (P2, T2). In our case (0.0401bar, 29 Deg C).
  
  The water will be saturated when its properties are defined by the side of curve pointed by the pink line. We do not want to remain on the right hand side of curve!
  
  @Ramani sir. I hope the explanation is correct 😀
  
  
• 

  Ramani Aswath

  PrinceTan

  Are you suggesting that if we can somehow maintain a pressure of 0.0401 bar within the concealing vessel where the steam is then we can prevent the steam from condensing even at 29 degree Celsius? Will it affect the heat energy level within the steam so that it can still turn a turbine to generate electricity? It shouldn't be affected should it?

  If that is your problem all that you need to do is to provide good thermal insulation on the steam containing vessel. The heat transfer coefficient on the air side (ambient) is very poor. A good insulation will solve the problem. You cannot run a turbine with steam at 0.04 bar.
• 

  ISHAN TOPRE

  bioramani

  If that is your problem all that you need to do is to provide good thermal insulation on the steam containing vessel. The heat transfer coefficient on the air side (ambient) is very poor. A good insulation will solve the problem. You cannot run a turbine with steam at 0.04 bar.

  So you are basically saying that the steam should not make contact with anything of 29 Deg C!
• 

  Ammar Aziz

  Yes we can prevent the steam from condensation if we mix it with another compound to make a composite.
• 

  Ramani Aswath

  Issue

  So you are basically saying that the steam should not make contact with anything of 29 Deg C!

  You are right in that if steam sees a surface at 29 C it will condense. We are using the pressure and temperature of steam to generate a high velocity stream of steam that rotates the turbine. We are not using the latent heat of vaporization. This is recovered in a condenser after the steam exits the turbine.
  
  Incidentally, your curve and the explanation is right. However, for a turbine application what is considered is the kinetic energy of the steam. In power plant turbines the steam is exhausted at well below atmospheric pressure in a partially condensed state. It is not 'dry' steam.
• 

  PrinceTan

  Ammar Aziz

  Yes we can prevent the steam from condensation if we mix it with another compound to make a composite.

  Pls suggest the compound added to prevent condensation so that I can look it up, thank you..
• 

  PrinceTan

  bioramani

  If that is your problem all that you need to do is to provide good thermal insulation on the steam containing vessel. The heat transfer coefficient on the air side (ambient) is very poor. A good insulation will solve the problem. You cannot run a turbine with steam at 0.04 bar.

  Thanks for the information, its been of great help.. I'll look it up and modify it to suit my system..
• 

  Rishabh1234

  are u suggesting that steam at saturated temp. and pressure gets condensed if it comes in contact with any surface at the same temprature. how so ?
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  Ramani Aswath

  Rishabh1234

  are u suggesting that steam at saturated temp. and pressure gets condensed if it comes in contact with any surface at the same temprature. how so ?

  If the steam pressure is more than the saturated vapour pressure of water at any temperature t, a portion of it will condense at temperature t till the pressure equals the staurated vapour pressure.
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  Rishabh1234

  so whats the basic problem in using steam at lower temprature for energy generation ?
• 

  Ramani Aswath

  Rishabh1234

  so whats the basic problem in using steam at lower temprature for energy generation ?

  Energy is the problem. Steam at 29 degC has negligible energy. It is at an absolute pressure of about 1/25th of atmospheric. Actually a very good vacuum.
  How can this be used to drive any turbine? Turbines used for power generation are pressure proof and the steam exhausts into a vacuum condenser. Even this will be higher than the 29 degree indicated.
  Putting it another way, if you upend a glass over a plate of waterat 29 degC soon it will be filled with 'steam'. Can we imagine that turning a turbine?
  Steam Turbine