The power of the cooling tower motor should be selected according to the power required for the operation of the cooling tower, and the cooling tower motor should be tested to run under the additional power load. Please pay attention to the following two points when selecting a cooling tower motor:
(1) If the selected cooling tower motor power is too small. There will be a "small horse-drawn cart" phenomenon, causing the cooling tower motor to be overloaded for a long time. Thermal damage to its insulation layer may even burn the cooling tower motor.
(2) If the selected cooling tower motor power is too large. There will be a "big horse-drawn trolley car" phenomenon. The output power of the cooling tower motor cannot be fully utilized, and the power factor and power are not high (please refer to the table), which is not only bad for users and the power grid, but also causes excessive electricity bills.
In order to correctly select the power of the cooling tower motor, the following calculations or comparisons should be made:
(1) Regarding the continuous operation mode of constant load, if the power of the load is known (that is, the power of the cooling tower), it is Pl (kw). The required cooling tower motor power P(kw) can be calculated as follows: P = P1 / n1n2 during which n1 is the power of the cooling tower; n2 is the power of the cooling tower motor. The power calculated by the above company is not necessarily the same as the required cooling tower motor power. Therefore, the additional power of the selected cooling tower motor should be equal to or slightly greater than the calculated power.
Example: The power of a cooling tower is 3.95kw. The cooling tower power is 70%. If you choose a cooling tower motor with a power of 0.8, how much kw should the power of the cooling tower motor be? Solution: Since there is no 7.1kw specification, so P = P1 / n1n2 = 3.95 / 0.7 * 0.8 = 7.1kw. Therefore, a cooling tower motor of 7.5kw was selected.
(2) Compared with the cooling tower motor of the same power, the cooling tower motor for short-time rated operation has a large maximum torque, light weight and low price. Therefore, when conditions permit, short-term additional cooling tower motors should be used as much as possible.
(3) Regarding the additional intermittent operation of the cooling tower motor, the power should be selected according to the size of the load duration, and the motor dedicated to the intermittent operation mode should be selected. The calculation formula for the duration Fs% of the cooling tower motor load is FS% = tg /(tg + t0)×100%, during which tg is the operating time. t0 stop time is minutes; tg ten t0 to is the minimum cycle time.
Guangdong Trlon Energy-saving Air Conditioning Equipment Co., Ltd.
Company Address： 1916A, Block A, David Donglong Business Building, Longhua, Longhua District, Shenzhen