Product name:cooler for high voltage variable frequency motor
It is equipped with AC and DC motors，this model has the advantages of small size, good cooling effect, low noise, small vibration, convenient installation and maintenance, energy saving, and is especially suitable for the environment of water shortage and dust.
Air-Air Cooler is a separate cooling unit. It is installed as a whole with the motor,form a closed cooling system.Through circling fan and cooling fan, the hot air inside the motor through the cooling tube, constantly being cooled by outside air, To ensure that the motor under the conditions of safe and reliable operation.
1.Optimize the number of cooler tubes, reduce inner wind road pressure drop and temperature rise of the motor
2. Spirally fluted tube, Increase the heat transfer area, improve the heat transfer efficiency
3. Improve the external fan blade diameter, reduce the noise pollution
4. Improve the external fan blade width,increase air volume
1.M type tube row structure,reduce inner wind road pressure drop,increase air volumn and reduce motor temperature rise
2.About the cooler inner wind road pressure drop, Geometric shape, number of tube rows, flow rate and fluid thermophysical parameters
△P=f(µ,S1,S2,d,Z, η, ρ)
Dimensionless form（Euler Nu）:Eu=△P/(ρ*µ²/2)
inner wind road pressure drop△P=Eu*ρ*µ²*Z/2
µ---flow rate,S1 S2tube distance,d—tube dimater,Z--tube row number, η—viscosity, ρ—density
About the formula, Variation of thermophysical parameters,at the same air condition, little change in temperature range.then main factors which affect pressure drop are µ,S1,S2,d,Z,. Although the flow rate has a greater impact, number of tube rows also important
Besides,speed,tube distance and tube diameter,they are all adjustable parameter,only number of tube rows can’t adjust largely due to the arrangement of matrix. This means the irreversible parameter in the same structure.Our company decide to use M type tube row.
Originally,the American Westinghouse air cooler is a M type tube row structure, generally in the 5-6 row, and now its based on the air cooler structure change to 1.5-3 M tube row structure,in general 3-4 row, so that the air cooler inner wind road four return, internal circulation wind through 4 times of tube row, only 12 rows, which has obvious effect on decreasing the pressure drop and increases with the air volume.
According to the heat balance:
Air volume Q0=(ρ0×CP0×△T), if heater exchanger M=Const,temperature rise△T down, Air volume Q increased.
This means that the average temperature of the inlet and outlet of the system is reduced, so the temperature rise of the motor coil is also decreased.
2.The spiral groove tube ,increases the heat transfer area per unit length, but also increases the turbulence degree of the air flow, reduces the thermal resistance in the heat conduction, and improves the heat exchange performance.
3. Adopt smaller fan blade diameter and the wider inlet and outlet blade can reduce the fan noise, increase the air volume of the outer air path, and improve the heat exchange performance of the air cooler.
The original of the external air path of cooler is affected by ABB, and most of them are small and narrow. The impeller diameter is usually used to achieve the required flow rate, but result in noise increases.
Sound power level LW=LWo+10Lg（Q×P²） [dB]
According to the fan similarity theory: P1=P2×(D1/D2)²
D1<D2，Lw=Lwo+10Lg[Q×P22×（D1/D2） 4] [dB]
If the air volume Q is the design value constant, the outer diameter of the wind blade from D2 increases to D1, the noise LW also increases with the logarithm of the ratio of D to the outer diameter of the P and the two product of the pressure side. Therefore, in order to achieve the design value of air volume, with increasing the diameter of the impeller method to reduce noise is unfavorable. In addition, due to the height of the center of the motor, the impeller diameter increases, the wind shell cavity decreases, cause the impeller rotates the wind through the shell space dynamic pressure - energy conversion process is affected by the static pressure of the fan, the loss increases, efficiency reduce
The mechanical dimensions and tolerances of this series of motors conform with the China national standard GB l800-1804 and the ISO standard.
1.Please indicate the motor type,rated output,rated voltage,rated frequency,synchronous speed,Explosion proof Mark,mounting type,rotation direction(view from the shaft extension side)Use of the environment(indoor or outside)If the user havn't point out the rotation and environment,normailly we think is CW roration and used indoor.
2.when user have special requirments,order can be confirmed after signing the technical agreement with engneering and technical department.