Time required to heat a substance
Time required to heat a substance
(OP)
Does anyone know how to calculate the time required to heat a substance given the heat requirements and material properties?
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Time required to heat a substance
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RE: Time required to heat a substance
Assuming your substance is a solid, then I believe your problem can be solved by applying a well known analytical solution for transient heat conduction in a semi-infinite solid.
If the substance is initially at a uniform temperature and the surface temperature is suddenly changed, then the analytical solution will provide the temperature at a given depth as a function of time.
Alternately, if your sample is small, or thin, and is heated uniformly on all surfaces (e.g., a ball bearing suddenly immersed in a heating or cooling fluid), then an analytical solution is available by using a well known transient lumped parameter approach. This method assumes that the entire mass is heating up uniformly.
If you are heating a fluid or gas, then additional physics must be included.
I can help you with the calculation and provide the equations if you can provie a few more details regarding the geometry, material type, and method of heating.
RE: Time required to heat a substance
If you know the "Specific Heat Capacity" of your substance you can calculate as follows:-
Q= m*Cp*(t2-t1)
where Q = heat req in joules
m = mass of substance
t1 & t2 = intial and final temperatures of the
substance in Kelvin
further Power=Q/T
where Q is heat req in joules
P is power in watts
T is time in seconds
so assuming you know the power rating of your heat source you can transpose to find T time to heat your substance.
example
4kg of water requires heating in a kettle from say 293.15K
to 373.15K , specific heat capacity of water 4187J/kgK
the kettle has a power rating of 2000W
therefore Q= 4*4187*(373.15-293.15)= 1339840J
so to find the time to raise the water temp use P=Q/T
so T= Q/P = 1339840/2000 = 669.92 seconds or 11.165 minutes
hope this helps
regards desertfox
RE: Time required to heat a substance