Equation from Btu/ft/hr to Temperature Lloss
Equation from Btu/ft/hr to Temperature Lloss
(OP)
I need to calculate the temperature loss when I remove the insulation from various pipework systems. I have a calculator from 3E Plus which gives an output in 610 Btu/hr/ft and I want to convert that back to a temperature loss.
I have
Specific Heat Capacities of the various fluids in the system
Flow rates of various fluids
Inlet and ambient Temperatures
Any help would be appreciated
I have
Specific Heat Capacities of the various fluids in the system
Flow rates of various fluids
Inlet and ambient Temperatures
Any help would be appreciated





RE: Equation from Btu/ft/hr to Temperature Lloss
You'll need the fluid density to figure how much fluid by mass is in each foot of pipe.
You'll need the velocity to figure how long the fluid spends in the pipe.
Move things around and throw in some 60s in various places until the only units left are temperature.
RE: Equation from Btu/ft/hr to Temperature Lloss
If Q is the heat loss from 3E or whatever program, then for a single phase liquid, the temperature drop can be estimated from:
Q = mCpdT where
m is the mass flow rate
Cp is the heat capacity
dT is the temperature drop.
If you have a phase change then you can use the latent heat to estimate how much of the vapor will condense to 'supply' the heat loss to the ambient surroundings.
RE: Equation from Btu/ft/hr to Temperature Lloss
You definintely also need to know whether the flow is laminar or turbulent, fully developed or not (the pipe network is long, yes? if so it is likely fully developed). Hit me back when you know and i will be happy to help you.
Re = density*velocity*diameter/(dynamic viscosity)
or
Re = velocity*diameter/(kinematic viscosity)
if Re >2300 it is turbulent <2300 then it is laminar.