For　combined　sensible-latent　heat　storage　system　(CSLHS)　(termed　as　the　hybrid　configuration),　macro　encapsulation　can　effectively　solve　the　leakage　problem　of　PCMs.　However,　due　to　the　poor　thermal　conductivity　of　PCMs,　the　charging　performance　of　the　hybrid　configuration　slightly　increases　compared　to　the　solid　structure　(with　only　sensible　materials).　Meanwhile,　the　natural　convection　in　the　PCMs　zone　could　improve　the　charging　performance.　So,　how　to　improve　natural　convection　intensity　is　a　key　issue　for　the　CSLHS　by　macro　encapsulating.　It　is　found　that　adding　fins　can　significantly　enhance　natural　convection　and　accelerate　the　melting　of　PCM.　In　this　paper,　we　proposed　the　hybrid　configuration　with　fins　built-in　by　macro　encapsulation,　and　analyzed　its　charging　performance　with　different　fin　structural　parameters　in　the　PCM　zone　by　CFD　simulation.　In　the　case,　the　sensible　heat　storage　material　is　high-temperature　concrete　and　the　PCM　is　a　low-melting-point　mixed　molten　salt.　We　analyzed　the　effects　of　fin　number,　fin　length　and　fin　thickness　on　the　charging　performance　of　the　hybrid　configuration　respectively.　From　the　result,　the　charging　performance　increases　with　the　fin　number,　but　the　increase　rate　gradually　decreases.　When　the　fin　number　is　6,　the　charging　performance　increases　by　20.18%　compared　to　the　situation　without　fin.　The　charging　performance　increases　gradually　with　the　fin　length.　Compared　with　the　hybrid　configuration　without　fin,　for　each　10　mm　increase　in　fin　length,　its　charging　performances　increase　by　4.09%,　5.26%,　7.02%,　8.77%,　11.70%,　and　15.79%,　respectively.　Different　from　number　and　length　of　fins,　the　effect　of　thickness　on　the　charging　performance　is　very　small.　When　the　fin　thickness　increased　from　1　mm　to　4　mm,　the　charging　performance　only　increased　by　2.3%.　It　indicates　that　the　main　reason　for　the　improving　the　charging　performance　is　to　increase　the　natural　convection　intensity　by　dividing　the　PCM　zone　through　fins.　These　results　show　that　the　charging　performance　of　the　CSLHS　with　macro　encapsulation　can　be　improved　by　optimizing　fin　structural　parameters.　©　Science　Press,　Institute　of　Engineering　Thermophysics,　CAS　and　Springer-Verlag　GmbH　Germany,　part　of　Springer　Nature　2024.