Steam Heater Rate

[stanbecnel]

I have a skid mounted steam heater used for heating oil and gas in a well testing application and I am trying to calculate the rate in MMBTU/HR. The heater is made up of coils that flow back and forth through a water/glycol (40% glycol) bath that is heated with a seperate steam generation unit. The fluid that is being heated will be a mixtures of 20 MMSCFD natural gas and 1200 BBL/Day oil.

This is a brief overview; can anyone give me some guidance about how to about calculating the rate of this unit?

Thanks in advance,

Stan Becnel

 

[IRstuff]

If you know the mass flow rate of the steam and its change in temperature, that'll get you close to the heating rate

TTFN

FAQ731-376

 

[ione]

I suppose steam is condensing (otherwise why use steam as thermal vector?) and so you need to know the steam mass flow rate, as indicated by Irstuff and its latent heat. Latent heat makes the job.

 

[MrBTU]

I believe you are talking about the DUTY of the heat exchanger and not the RATE. The DUTY can be calculated by either the steam side (as described above) Q=m(h), or by the oil side, Q=m(cp)deltaT. Most oils have a cp of around .5, so you need the mass flowrate of the oil, the specific heat of the oil, and the temp rise of the oil. Or the mass flow rate of the steam and the latent heat of the steam.

 

[ione]

If I am not mistaken, the OP described a mixture and not a pure fluid to be heated. If the thermal properties of the mixture (i.e. specific heat cp) are not accessible it is quite tricky to find an effective response to the problem. On the other hand if one already knew the steam mass flow rate required for the process, the problem would be extremely easy.