The　poor　heat　transfer　performance　of　the　heat　exchanger　leads　to　low　heat　storage　efficiency　of　the　latent　heat　storage　device.　To　improve　the　heat　transfer　performance　of　the　heat　exchanger,　a　novel　annular　fin　with　inclined　angle　is　proposed　to　enhance　heat　transfer　of　the　heat　exchanger.　12　fins　with　different　structural　parameters　are　designed　and　welded　to　the　inner　tube　wall　of　the　heat　exchanger.　The　simulation　model　is　in　good　agreement　with　the　literature　and　the　model　is　considered　to　be　reliable.　Based　on　the　enthalpy-porosity　model,　the　liquid　fraction,　temperature　distribution,　melting　front,　energy　storage　density　and　heat　storage　rate　were　used　to　compare　and　optimize　the　structural　parameters　of　the　annular　fins.　Results　demonstrated　that　the　difference　in　complete　melting　time　due　to　the　number　of　fins,　fin　arrangement,　fin　length　and　fin　angle　were　43　min,　85　min,　17　min　and　10　min,　respectively.　The　fin　arrangement　was　the　most　significant　in　reducing　the　heat　storage　time.　Compared　to　N　=　4　and　uniformly　distributed　fins,　non-uniformly　distributed　fins　reduced　the　total　melting　time　of　stearic　acid　by　53.13　%　and　20.54　%.　To　be　conclusive,　the　addition　of　non-uniformly　distributed　annular　fins　with　70°　inclination　enhanced　the　heat　transfer　in　the　heat　exchanger　and　saved　a　significant　amount　of　heat　storage　time.　©　2023　Elsevier　Ltd