In the field of electric heating equipment, the power of electric heating has a relatively large impact on the effect of electric heating sheets, electric hot wires and other products, today I will briefly introduce some electric heating design and calculation
1. Calculate the power required to heat to the set temperature within the specified time from the initial state as required.
2. Calculate the power required in actual work under the premise of maintaining the temperature of the medium.
3. The selection of heater model and quantity, the total power is taken from the maximum value of the above two powers, and the coefficient of 1.2 is considered.
Heating formula
Formula:
1. The power required for initial maintenance of heating Kw = (C1M1△T+C2M2△T)/863/H+P/2
P The heat dissipation unit of the container at the final temperature: kilowatts
H is the unit of time required for the initial temperature to heat to the end: hours
M1 and M2 are the mass of the container and the medium, respectively, in kilograms
C1 and C2 are the specific heat of the container and the medium, respectively, unit: kcal/(kg °C)
△T is the difference between the final temperature and the initial temperature, unit: °C.
2. The power required to maintain the temperature of the medium: Kw=C2M3△T/863+P
M3 is the unit of medium increased per hour: kg/h.
In order to facilitate the rapid selection on site, some quick calculation formulas are provided
1. The power required for heating still water and oil (without considering the heat consumption of the container) Kw=CM△T/863/H
C: Specific heat kcal/(kg.°C)
M: Mass kg △T
H: Time: hours.
2. The power required for the heating of flowing water and oil (regardless of the heat consumption of the container) Kw=CF△T/14
C: Specific heat kcal/(kg.°C)
M: Flow rate kg / min △
T: Temperature difference °C.
3. Channel air heating (normal pressure) Kw=F△T/40
M: Flow meter 3/min
△T: temperature difference °C
40: Series kilowatts. Minutes (m3/min)
Vout=Vin(Tout+273)/(Tin+273)
Vin, Vout: Channel inlet and outlet flow rate
Tin, Tou: channel inlet and outlet temperature °C