Could you specify your question? The conversion from water vapor to water is per definition a condensation process.

If you want to avoid a definitive condensation step then you need to go via supercritical states, ie pressures above 220 bar. In that case you will get a smooth transition from vapour to liquid, but note that during the pressurisation the temperatures would also need to remain high (>647 K).

A video showing how this works with CO2, FYI

http://www.youtube.com/watch?v=-gCTKteN5Y4

Dear Andreas, 

it is right that transformation of vapor into water is a condensation process. but my question is that, is any other method to convert vapor into water without using condenser. suppose when steam exit from the turbine after expansion and enters into condenser at low pressure. if we increase the pressure of exit steam at constant temperature then vapor may converted in water due to increasing saturation temperature.

1) Dear John: you're absolutely right, the way via supercritical state is a possibility I didn't think of

2) Dear Rajesh: for this approach (whatever the reason for this might be) you would have to increase the partial pressure of steam. Since addition of further heat would not be helping (steam would stay steam), you would have to add mechanical power. For steam, this can usually only happen via compressor or the like - and if you convert steam into water within a compressor, it might not have a very long life due to droplet erosion and such. Besides, most compressors are not isothermal (if I remember correctly) but isentropic (with an isentropic coefficient), so temperature might rise anyway.

thanks Andreas and john for giving me valuable suggestions. I'll concentrate and use it in my problem and will take help if required. once again thanks.

Though late, but still I would like to tell something.

For our project search, we analysed these conditions. We came to 2 results:

1) If we want to convert the low pressure steam coming out of turbine into water without cooling it, it needed none other then a compressor. And using the compressor for getting water proves harmful to the material of the compressor at long time.

2) In whatever the way, if we can safely convert the steam into water, these proved out of the economic budget of power plant, if you're seeking this suggestion for power plant efficiency or economy improvement.