The energy transfered with a substance can be expressed as
Q = m cp dt (1)
Q = quantity of energy transferred (kJ, Btu)
m = mass of substance (kg, lb)
cp = specific heat of the substance (kJ/kgoC, kJ/kgoK, Btu/lb oF)
dt = temperature difference (rise or fall) in the substance (oC, K, oF)
Example - Energy Transfer with Water
2 kg of water is heated from 20oC to 60oC. The specific heat of water is 4.2 kJ/kgoC. The heat transfered can be calculated as
Q = (2 kg) (4.2 kJ/kgoC) ((60oC) - (20oC))
= 336 kJ
= (336 kWs) (1/3600 h/s)
= 0.093 kWh
Work, heat and energy systems.
The First Law of Thermodynamics simply states that energy can be neither created nor destroyed (conservation of energy). Thus power generation processes and energy sources actually involve conversion of energy from one form to another, rather than creation of energy from nothing.
The efficiency of the Carnot cycle.
Heat transfer when steam condensates.
Conductive heat transfer takes place in a solid if there is a temperature gradient.
Heat transfer between a solid and a moving fluid is called convection. This is a short tutorial about convective heat transfer.
Energy is the capacity to do work.
The amount of thermal energy stored in heated water.
Convert between energy units
Classification of heat recovery efficiencies - temperature efficiency, moisture efficiency and enthalpy efficiency - online heat exchanger efficiency calculator.
Heat vs. work vs. energy.
Energy required to heat up a substance.
Heat transfer due to emission of electromagnetic waves is known as thermal radiation.
Calculating the amount of steam in non-flow batch and continuous flow heating processes.