Calculation of LFO Electrical Heater Capacity

[evgins]

Hi everbody,

i need some help about capacity calculation of light fuel oil electrical heater.

Heater Set point temp. is 35C deg.
Heating cap. 300kW
Using for heating LFO for Gas turbine
Fuel is Distillate Light Fuel oil
Mass flow flowing through the heater 9kg/sec.

When the LFO temperature falls below under 5C deg., is the heater capacity enough for heating fuel oil to 35C deg.?

 

[ione]

Q = M x Cp x deltaT
M = mass flow rate
Cp = LFO specific heat
deltaT = temperature increase
Q = power required

Assuming Cp = 1.8 kJ/(kg* °C) the answer to your question is definitely no.

 

[IRstuff]

Is this for school?

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[evgins]

this question is not for school.

my manager asked this question to me.

Thanks for answers.

 

[IRstuff]

The reason for asking is the setup of the question, particularly from a first time poster.

Moreover, the heating capacity is so far away from being able to support a delta T of 30°C that it raises questions about why the question is even being asked. Perhaps, as a self exercise you should figure out what the maximum possible delta T could be supported by the heater.

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[willard3]

Is yours an Engineering function?
Have you studied and do you understand thermodynamics?

 

[evgins]

Thanks all for explanations

Yes i studied engineering and thermodiynamic lessons. I calculated that this heater capacity is not enough for making 30 C deg. delta T difference.
But my manager didnt beleieve me about this issue. So i think that i made wrong calculation and i asked the question here.

Thanks again

 

[IRstuff]

The equation that ione provided already demonstrates that the heater is underpowered, and that's without including the actual efficiency of the heater.

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[ione]

Maybe your boss needs to take a (basic) thermo course

 

[evgins]

maybe

 

[chicopee]

Heat transfer loss should also be included espacially if the LFO tank is located outside under cold temperatures.