Study On The Performance Of Cascade And Stage And Of Helium Compressor With Heavy Stage Load

As a result of working fluids'difference, there is a problem that the pressure ratio of single stage of the helium compressor designed according to conventional air-compressor rule will be smaller. By way of the verification, the high-turning-angle cascade suitable for helium can make the stage-load level increasing; the helium-compressor using this new stage design method, has realized the improving compression ratio, reducing series.In this paper 324 new-type cascades composed of the five parameters combination are simulated by the software Fine/turbo made by NUMECA, and the data of results is studied associatedly. Based on this, 162 types of stages composed of the five parameters combination are calculated. The results of the study indicate that: the rule that the diffusion factor reflects the pressure loss under conventional design in high-load cascade is no longer applicable; under the same loss coefficient conditions, there is a critical inlet-airflow angle making the turning-angle to achieve maximum, this critical intake angle almost only related with solidity; In larger solidity (1.15 and 1.5), the blade maximum thickness ratio affects the loss considerably, applicating of thin blade is advantage; the load of the new stage is greatly enhanced, and the efficiency can maintain at a higher-level. Research data can lay a foundation for further research on high-load helium-compressor.Based on the data of the calculation about cascades and stages, the high-load three-dimensional stage and the conventional three-dimensional stage compared to are designed. And the flow of the three-dimensional stage is simulated. Simulation results show that, the project of this new three-dimensional stage design is reasonable. There is a project of the high-load three-dimensional stage that in the middle of the radius every parameter is respective that inlet Mach number is 0.465, the energy coefficient is 1.0, the flux coefficient is 1.141, the reaction is 0.5, the solidity is 1.475. The pressure ratio reaches 1.1388, the stage efficiency is 89.86% as a simulated result under the design condition. The pressure ratio and the stage efficiency is respective 1.137 and 90.05% under the 90% of the design flux. The pressure ratio and the stage efficiency is respective 1.139 and 88.99% under the 110% of the design flux. And that, compared to it, there is a project of the normal three-dimensional stage that in the middle of the radius every parameter is respective that inlet Mach number is 0.281, the energy coefficient is 0.419, the flux coefficient is 0.5998, the reaction is 0.5, the solidity is 1.475. The results of normal design are that the pressure ratio is 1.067, the stage efficiency is 87.78% under the design condition.