HEI Design conditions

[roker]

Hello to all,

We received a specification for a vacuum unit of an Air Cooled Surface Condenser, one of the operating conditions is :"HEI DESIGN CONDITIONS", please can one advise this demand?

Best regards,
roker

 

[davefitz]

HEI is short for "heat exchanger institute", and they have several standards published on the topic of condensers.

see below link <

http://www.heatexchange.org/pub/steamsurface.htm>

I am not familiar with their topics that address air cooled condensers. However, my recollection of the earlier version that was available in 2003 is that it does not adequately afford a conservative design in the case where there is a large steam bypass system discharging into the condenser.

 

[MJCronin]

roker...

I believe that the specification is referring to that maximum(reasonable) vacuum value that is required for a condenser.

I know HEI has such a value in either the Liquid Ring Vacuum Pump standard or the STeam Jet Air Ejector Standard.

However, I do not believ that the HEI has a value for an air-cooled condenser

 

[speco]

Roker,

I haven't seen this spec for many years. However, one aspect of it was that a certain amount of air leakage into the system had to be accounted for in the design of a condenser. My memory tells me that the result was a 80/20 mol fraction mixture of steam and air at the outlet, thus reducing the condensing temperature at that point.

Regards,

Speco

 

[rmw]

Rereading the OP several times, I think it is the air removal equipment that is being referred to HEI standards.

Here is a further link from the site that DaveFitz posted that may give you the leads you need.

http://www.heatexchange.org/pub/eduinfo.htm

Whether you use steam jets or liquid ring vacuum pumps, you should choose a manufacturer that adheres to these design standards.

Their publications are not free, however.

rmw

PS: the maximum vacuum possible in a steam condenser is a function of the hotwell condensate temperature (which, of course is a function of approach to the cooling water - or air - temperature.)