| The rotating machinery such as fan, pumps et al. is widely used in powerequipment of metallurgy, mining and electricity et al. in the process of industrialproduction in China. Its power consumption accounts for a large proportion ofindustrial electricity in China. However, the variable-speed regulation of fan andpumps can save a lot of electricity. It has important significance in the efficient useof energy. At present, the power machine of industrial production is toward to thehigh-power and large-capacity. The operating power of fan and pumps is increasedto thousands of kilowatts to ten thousands of kilowatts. However, the existingtechnology of speed regulation is difficult to achieve wide speed range andhigh-efficiency transmission in the case of high power and high-capacitytransmission power. For this purpose, variable-speed regulation for high-power fanand pump has been studied to explore new technology solutions. It has importantsignificance in saving energy of large rotating machinery, improving the safety andthe reliability of equipment operation.The paper is supported by fundamentalscientific research expenses project in Jilin university, whose name is”study onmulticomponent hydrodynamic variable-speed system with high power”. In thispaper, a gearing of constant speed input and infinitely variable speed output that ismultiple hydrodynamic speed regulation system with large capacity is studied. Thesystem is based on the principle of power split transmission. It has large transmissionpower, wide speed range and high transmission efficiency. The study which involvedthe key issues such as transmission system model, the power analysis of speedregulation system, guide vanes adjustable torque converter and the outputcharacteristics of the system et al. can be summarized as follows:（1）The paper describes two programs of transmission system that is the transmission mode of dual-motor parallel and single-motor drivability based on theprinciple of power split. The characteristics of the two modes are analyzed. Thetransmission model based on the principle of power split transmission of multi-speedregulation system is proposed. The different phases of the multiple hydrodynamicspeed regulation system are briefly analyzed.The power flow of the two-ranked star wheel is analyzed using the node method.The power flow of the hydrodynamic speed regulation system which consists oftwo-ranked star wheel and adjustable torque converter is analyzed using the samemethod. The results are as follows: the formula between the speed, torque and powerof fixed planetary gear train and rotating planetary gear train, the formula betweenthe speed, torque and power of pump wheel and turbine wheel of guide vanesadjustable torque converter and the efficiency formula of the speed regulationsystem.（2）The hydrodynamic component of speed regulation system that is guidevanes adjustable torque converter is designed using a similar method. The loopround and blade of the torque converter is completely designed. The adjustabletorque converter of710mm diameter is obtained. The calculation model of flow fieldof the designed converter is established. The CFD numerical simulations ofadjustable torque converter with different openings and different working conditionsare done. The internal flow characteristics and the external torque characteristics ofthe torque converter are predicted.At the same time， the velocity modulatedhydrodynamic coupler and hydrodynamic retarder are studied by means of numericalsimulation.The original characteristic of hydrodynamic coupler with differentcharging ratio is analysed and the braking characteristic of hydrodynamic retarder isobtained.（3）On the basis of the characteristics calculation of hydrodynamic couplerwith different charging ratio and the adjustable torque converter with differentopenings, the output characteristic of hydrodynamic speed regulation system in low speed range and high are predicted respectively. To match the speed regulationsystem and centrifugal fans, the relationship of guide vane opening and the systemoutput characteristics is studied. The output speed and torque of the speed regulationsystem increase with the increase of the guide vane opening. The power of torqueconverter and the accounted ratio of the hydrodynamic power also increase. Thevariation regular of characteristic parameters of guide vanes adjustable torqueconverter is also studied. The impact of parameters of fixed planetary gear on theefficient interval range of hydrodynamic speed regulation system is analyzed. Theefficient interval range of speed regulation system with the increase of thecharacteristic parameters of the fixed planetary gear moves to the low speed range.In the speed range, the speed regulation system of the transformation has higheroperating efficiency than the original. Finally, the efficiency curve of load speed ofcentrifugal fan is compared between the speed regulation system and thehydrodynamic coupling. The hydrodynamic speed regulation system can achievemore efficient transmission in a wide speed range and has more significantenergy-saving advantages. |
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