The effects of different heat transfer fluid(HTF) parameters on charging and mechanical performance of the thermal energy storage(TES) tank using phase change material(PCM) capsules are studied by employing the fluid-solid coupling calculation. The results show that

with the inlet HTF flow velocity increased from 0.000 7 m/s to 0.000 9 m/s

the total heat storage quantity is basically unchanged

the average charging power increases from 5.33 MW to 6.79 MW

and the peak maximum mechanical stress(MMS) of the tank wall decreases. When the initial cold HTF temperature decreases from 610 K to 530 K

the total heat storage quantity increases

the average charging power increases from 5.29 MW to 6.81 MW

but the peak MMS of the tank wall also increases. With the initial hot HTF temperature increases from 730 K to 810 K

the total heat storage quantity increases obviously

the average charging power increases from 3.81 MW to 7.97 MW

but the peak MMS also increases to 159.6 MPa. Hence

to improve the charging performance of the TES tank

on the premise of ensuring the structural safety of steel wall of the TES tank

the inlet HTF flow velocity and initial hot HTF temperature should be increased properly

and the initial cold HTF temperature should be reduced properly.