3 replies to this topic

[Rahimzadeh]

Dears:

what is difference between turbo expander and pressure reducing valve function in nitrogen plant?

 

best for all of you

M.R.Rahimzadeh

[gegio1960]

rahimzadeh,

you can compare the N2 expansion to the steam expansion.

With the expansion thru the valve (letdown) you realize an isoenthalpyc process: you simply cool the nitrogen.

With the turbine you realize a (non ideal) isoentropic process that allows the recovery of work (other than cooling the nitrogen).

regards

[Pilesar]

When nitrogen pressure is reduced through an expander, the resulting nitrogen is at a lower temperature than if the pressure were reduced by passing through a valve. It is the availability of using the lower temperature nitrogen for refrigeration that makes the expander such a key piece of equipment. The work recovered is a bonus. In small plants, small expanders might even be attached to a hydraulic brake instead of to a compressor or generator. The brake wastes the driving power, but allows the benefits of low temperature at a lower capital cost.

[Rahimzadeh]

thank you .your respose satisfied me.