Steam Heat exchanger : max rho v2 when does it occour..?

[jamesbanda]

All,

maybe this sounds a daft question but i'd like some feedback on the following..

if you are using 150psig steam on a reboiler, usually you control flow to the reboiler with a CV, then the pressure drops on the steam, velocity rises..

so, if you assume 150 psig for all these case you dont calculate rho v2 right.. so how do you normally estimate chest pressure..

at max capacity of the reboiler
the chest pressure but so is density
mass flow is at a maxmium

at normal rates
the chest pressure is lower,
mass flow rate is lower.

at min rates

Chest pressure is at a min lowest density​

Rates are at a min​

this is what i think you do..

set the design into rating mode.. and modify chest pressure for the cases above until rated capacity =100% at that chest pressure.