The　single　tank　molten　salt　thermal　energy　storage　(TES)　system　has　been　extensively　studied　due　to　its　low　cost　and　high　efficiency　performance.　The　binary　nitrates　(KNO3+Ca(NO3)2)　is　selected　as　heat　storage　medium　in　this　study,　which　the　melting　point　is　116.9　°C.　This　research　aims　to　achieve　stable　and　constant　heat　discharging　performance　of　the　single　tank　molten　salt　TES　system.　Three　different　inlet　velocity　conditions　such　as　constant　value,　manual　and　automatic　adjustment　are　comparatively　studied.　The　results　show　that　the　heat　discharging　power　drops　with　the　heat　discharging　time　increases　under　constant　inlet　velocity.　The　heat　discharging　time　decreases　with　the　increasing　of　inlet　velocity　while　the　heat　discharging　power　increases　with　the　increasing　of　the　inlet　velocity.　The　correlations　between　the　inlet　velocity　and　heat　discharging　time,　the　average　temperature　of　molten　salt　in　the　single　tank　are　proposed.　The　heat　discharging　power　of　manual　and　automatic　adjustment　of　inlet　velocity　is　in　±10%　and　±3%　fluctuation　of　the　set　value.　The　results　could　provide　practical　and　effective　guide　to　design　the　single　tank　molten　salt　TES　system.　©　2020　Elsevier　Masson　SAS