heating oil

[mielke]

Is there any other common ways of heating engine or hydraulic oil than by an immersion heater (either inline or in tank)?

 

[CRG]

Have you considered a pad heater on the tank?

 

[mielke]

This is going to be for a tank of oil (10 gallons)that is going to be tapped into and recirculated. and not for an engine

 

[CRG]

mielke,

Perhaps a little more information would help with suggestions. How much heat do you need? What is the flow going into the tank?

 

[mielke]

I figure we remove about 15 kw with a flow rate of 2 gpm

 

[mielke]

and operating pressure of the oil can get upto 200psi

 

[CRG]

A quick calculation gives me a delta T of over 100 degF for 2 gpm of oil? Is this correct?

 

[mielke]

sorry crg it was a type. i have about 2 gpm of oil and want to put in 5 kW (not 15) of heat load at 200psi. which is roughly a 45F temp rise.

 

[ione]

I have calculated a different deltaT. Where am I wrong?

deltaT = Q/(M*cp)

Where:

deltaT = temperature increase (°C)
Q = heat =5kW = 4300 kcal/h = 71.7 kcal/min
M = mass flow rate = 2 gpm * 0.0038 m^3/(gpm min)* 880 kg/m^3=6.688 kg/min
cp = specific heat = 0.48 kcal/(kg °C)


deltaT = 22.33 °C = 72.2 °F

 

[mielke]

ione,

your wrong because one degree C = 1.8 degree F. that means if you have a deltaT of 22.33C then you have a deltaT of 40.194F.

But a temperature of 22.33C is the same as a temperature of 72.2F. But this is totally different than a deltaT because F and C are not on an absolute scale.

 

[ione]

yup! I was definitively wrong

 

[MrBTU]

mielke, I assume you want to heat this oil up for cold startup? In that case you typically would not have any other heat source from the engine as a byproduct of combustion to heat the oil, so electric heating is the only option. A separate elecric heater with flow across the element would be more efficient than an immersion heater, however, you then have the pumping to consider and a separate shell.
Unless you can come up with another heat source, an electric immersion heater in the tank is your simplest option, especially if it is only for start-up.