Electric heater design power calculation formula and calculation example for easy understanding:
I.Power Calculation Formula:
1. Power required for initial heating
KW = ( C1M1△T + C2M2△T ) ÷ 864/P + P/2
Where:
C1C2 are the specific heats of the container and medium respectively (Kcal/Kg℃)
M1M2 are the masses of the container and medium respectively (Kg)
△T is the difference between the required temperature and the initial temperature (℃)
P is the heat dissipation of the container at the final temperature (KW)
2. Power required to maintain the medium temperature
KW = C2M3△T / 864 + P
Where M3 is the mass of the medium added per hour (Kg/h)
II. Calculation Example:
Take an open water tank with dimensions of 2m length, 1m width, and 1m height as an example. The container weight is 500Kg. The tank is filled with water weighing 2000Kg. The initial water temperature is 5℃, and it is heated to 65℃ within 3 hours. The heat dissipation of the container is estimated to be 3KW. Calculate the required power for initial heating and the power for maintaining the water temperature.
1. Calculate the power required for initial heating
C1 (specific heat of steel) = 0.11 Kcal/Kg℃
C2 (specific heat of water) = 1.0 Kcal/Kg℃
M1 = 500Kg
M2 = 2000Kg
△T = 65 - 5 = 60℃
P = 3KW
KW = (0.11×500×60 + 1.0×2000×60) ÷ 864/3 + 3/2 = (3300 + 120000) ÷ 288 + 1.5 = 123300 ÷ 288 + 1.5 ≈ 428.125 + 1.5 ≈ 429.625KW
2. Calculate the power required to maintain the water temperature
M3 = 2000Kg / 3h = 666.67Kg/h
KW = 1.0×666.67×60 / 864 + 3 = 40000.2 / 864 + 3 ≈ 46.296 + 3 ≈ 49.296KW
