Storing Thermal Heat in Materials
Energy stored as sensible heat in materials.
Thermal energy can be stored as sensible heat in a material by raising its temperature.
The heat or energy storage can be calculated as
q = V ρ cp dt
= m cp dt (1)
q = sensible heat stored in the material (J, Btu)
V = volume of substance (m3, ft3)
ρ = density of substance (kg/m3, lb/ft3)
m = mass of substance (kg, lb)
cp = specific heat of substance (J/kgoC, Btu/lboF)
dt = temperature change (oC, oF)
- ρ -
|Specific Heat |
- cp -
|Aluminum||max. 660 (melting point)||2700||920||2484|
|Cast Iron||max. 1150 (melting point)||7200||540||3889|
|50% Ethylene Glycol - 50% Water||0 - 100||1075||3480||3741|
|Dowtherm A||12 - 260||867||2200||1907|
|Draw salt - 50% NaNO3 - 50% KNO3) (by weight)||220 - 540||1733||1550||2686|
|Liquid Sodium||100 - 760||750||1260||945|
|Molten Salt - 50% KNO3 - 40% NaNO2 - 7% NaNO3 (by weight)||142 - 540||1680||1560||2620|
|Therminol 66||-9 - 343||750||2100||1575|
|Water||0 - 100||1000||4190||4190|
- 1 kJ/(kg K) = 0.2389 Btu/(lbm oF)
Example - Thermal Heat Energy stored in Granite
Heat is stored in 2 m3 granite by heating it from 20 oC to 40 oC. The denisty of granite is 2400 kg/m3 and the specific heat of granite is 790 J/kgoC. The thermal heat energy stored in the granite can be calculated as
q = (2 m3) (2400 kg/m3) (790 J/kgoC) ((40 oC) - (20 oC))
= 75840 kJ
qkWh = (75840 kJ) / (3600 s/h)
= 21 kWh
Example - Heat required to to heat Water
The heat required to to heat 1 pound of water by 1 degree Fahrenheit when specific heat of water is 1.0 Btu/lboF can be calculated as
q = (1 lb) (1.0 Btu/lboF) (1 oF)
= 1 Btu
Thermal Heat Energy Storage Calculator
This calculator can be used to calculate amount of thermal energy stored in a substance. The calculator can be used for both SI or Imperial units as long as the use of units are consistent.
V - volume of substance (m3, ft3)
ρ - density of substance (kg/m3, lb/ft3)
cp - specific heat of substance (J/kgoC, Btu/lboF)
dt - temperature change (oC, oF)
Work, heat and energy systems.
Air - Thermophysical Properties
Thermal properties of air at different temperatures - density, viscosity, critical temperature and pressure, triple point, enthalpi and entropi, thermal conductivity and diffusivity and more.
Liquids and Fluids - Specific Heats
Specific heats for some common liquids and fluids - acetone, oil, paraffin, water and many more.
Solids - Specific Heats
Common solids - like brick, cement, glass and many more - and their specific heats - in Imperial and SI units.