Features and precautions of heater

Characteristics of heating

The heating medium used in the heater can be water or steam.

The advantages of heater heating are:

(1) single unit heat supply is large, and the number of terminal equipment used is small under the same heat load;

(2) the small-scale heater can be hung without occupying the building area. The large-scale heater can be installed on the ground with limited floor area;

(3) fast start-up and temperature rise.

The disadvantages of heater heating are as follows:

(1) the fan has noise when the heater is running. Generally, the noise of small-sized heater is about 60dB (a), while that of large-sized heater is larger;

(2) the air heaters are all placed in the heating room to directly heat the indoor circulating air, without supplementing the fresh air (outdoor air), and cannot improve the indoor air quality.

In view of the advantages and disadvantages of the heater heating system, the heater heating system is applicable to the following situations:

(1) workshop or venue with large space, large heating load and indoor air circulation;

(2) places where the room temperature needs to be raised rapidly, such as factory workshops and venues;

(3) some non three shift production workshops with intermittent heating.

The heater heating system is not suitable for the following situations:

(1) where the air can not be recycled, for example: the workshop with toxic substances harmful to human body in the air; the process of producing flammable and explosive gas, fiber or dust, etc.

(2) rooms with relatively strict requirements for environmental noise.

Selection considerations

Small heater

(1) in order to make the temperature field in the workshop uniform and maintain a certain section speed, the number of air circulation times in the workshop shall be checked and calculated when selecting the heater, generally not less than 1.5 times / hour.

(2) when the heater is arranged, the jets of the heater should be connected with each other to form a general air circulation in the heating space.

(3) the heater shall not be arranged on the outer wall to blow vertically to the interior.

(4) the installation elevation of the bottom of the heater shall meet the following requirements:

When the outlet wind speed V0 ≤ 5m / s, take 2.5 ~ 3.5m; when the outlet wind speed V0 > 5m / s, take 4 ~ 5.5m.

(5) the range X of the heater can be estimated as follows:

X=11.3v0D

Where X - range of heater, m;

V0 - outlet wind speed of heater, M / S;

D-equivalent diameter of heater outlet, M.

(6) the air supply temperature shall not be lower than 35 ℃ and shall not be higher than 55 ℃.

Large scale heater

When selecting large-scale heater for heating, due to the large outlet speed and air volume, it should be arranged along the length direction of the workshop, the distance between the air outlet and the side wall should not be less than 4m, the air flow range should not be less than the length of the workshop heating area, there should be no structures or tall equipment in the range area, and the height of the air outlet from the ground should meet the following requirements:

When the lower chord of the plant is ≤ 8m, 3.5-6m should be taken;

When the lower chord of the plant is more than 8m, 5-7m should be taken;

The large-scale heater shall not be arranged near the workshop gate, and the height from the bottom of the air intake to the ground shall not be more than 1m, nor less than 0.3m.