Calculation of surface load power of electric heating tube

Recommended value of surface load power of electric heating tube (power per unit area of ​​heating area of ​​tube)

The following surface load generally refers to the metal mold heating and water heating, which can be multiplied by 2 to 2.5. Air heating is 50% to 60%.

Pipe diameter

Load value (Wcm square)

φ6～φ10

≤22

φ10.1 ～φ14

≤20

φ14.1～φ18

≤16

φ18.1～φ22

≤12

φ22.1～φ40

≤10

The square of the voltage should be divided by the resistance, which is 380*380/R

The resistance R is measured with a multimeter (current is difficult to measure)

If the size is measured, calculate the surface area and divide the power by the surface area to get the power density

Generally, the power density of domestic electric heating rods can reach 12w/cubic centimeter

Calculation formula for rated power of electric heating elements (electric heating wire, heating plate, etc.)

1. When the working voltage (220V) is 3 times, the electric heating element must be connected in star shape.

2. When the power line voltage is equal to the working voltage of the electric heating element (380V), the electric heating element must be connected in a triangle.

The power calculation formula of the common connection method of each phase electric heating element under symmetrical load is shown in the table, and the common connection method is shown in the figure.

These connection methods are widely used in household appliances and industrial and agricultural production appliances, and are often encountered in our production and maintenance. In the table, P is power, U is power line voltage, and R is the resistance of the electric heating element (such as electric furnace wire, infrared heating blood vessel, infrared heating plate, etc.).