ABSTRACT
The highly loaded design method of helium compressors can effectively solve the difficulty in compressing helium in High Temperature Gas-cooled Reactors (HTGR). But it also causes obviously different attack angle characteristics of blade surface loads in a highly loaded helium compressor compared to air compressors. This difference inevitably affects separation characteristics and flow loss within the compressor. In the current study, the effects of highly loaded design methods and changes in attack angle on the separation characteristics of the compressor cascade are analyzed by applying a numerical simulation method first. Then, the influence of Mach number on the loss characteristics of the cascade for a highly loaded helium compressor is systematically analyzed. Finally, the effect of differences in the material properties of working fluid on the separation characteristics is discussed. The results indicate that the proportion of secondary flow loss to the total loss in highly loaded compressor cascades is 2.46 times larger than that in conventionally loaded ones. While the properties of working fluid have an effect on the performance of the compressor cascade, their effects on the weight factor of vortex loss are highly limited.
Nomenclature
hu | = | Rotor work, J |
= | Average radius, m | |
T | = | Temperature, K |
n | = | Rotation speed, r/min |
u | = | Average tangential speed, m/s |
π0 | = | Total pressure ratio |
= | Torsional velocity, m/s | |
ζ | = | Total pressure loss coefficient |
b | = | Axial chord length, mm |
x | = | Position along the chord, mm |
h | = | Blade height, mm |
t | = | Pitch length, mm |
CP | = | Specific heat at constant pressure |
π | = | Static pressure ratio |
Cps | = | Static pressure coefficient |
Ω | = | Vorticity, s−1 |
Ωz | = | Axial vorticity, s−1 |
λx | = | Loss weight factor |
ϕ | = | Flow coefficient |
ψ | = | Loading coefficient |
δ | = | Reaction degree |
μ | = | Dynamic viscosity, N×s/m2 |
Abbreviations
HTGR | = | High temperature gas-cooled reactors |
PWR | = | Pressurized water reactor |
PV | = | Passage vortex |
CSV | = | Concentrated shedding vortex |
CV | = | Corner vortex |
S | = | Saddle point |
N | = | Nodal point |
LE | = | Leading edge |
TE | = | Trailing edge |
Subscripts | = | |
0 | = | Stagnation parameter |
1 | = | Inlet value |
2 | = | Outlet value |
* | = | Total value |
Acknowledgments
The present work is financially supported by the National Natural Science Foundation of China (No. 52206042), Natural Science Foundation of Liaoning Province (No. 2022-BS-096), Basic Research Project of Liaoning Provincial Department of Education (LJKMZ20220364).
Disclosure statement
No potential conflict of interest was reported by the authors.