Simultaneous　charging　and　discharging　(SCD)　of　the　latent　thermal　energy　storage　(LTES)　can　improve　the　flexibility　of　solar　thermal　systems　and　ensure　the　continuity　of　energy　supply.　Experiments　and　numerical　simulation　are　conducted　in　this　study　to　reveal　the　SCD　thermal　behavior　of　LTES　device　using　flat　micro-heat　pipe　array-metal　foam　composite　structure.　The　effects　of　heat　transfer　fluid　(HTF)　temperature,　volumetric　flow,　initial　phase　change　material　(PCM)　state,　and　metal　foam　are　analyzed.　Results　show　that　PCM　absorbs　heat　from　hot　HTF　or　releases　heat　to　cold　HTF　at　the　beginning　depending　on　the　PCM　and　HTF　temperatures.　The　SCD　eventually　reaches　an　approximate　steady　state,　cold　HTF　exchanges　heat　directly　with　hot　HTF,　power　and　PCM　temperature　remain　unchanged.　Low　cold　HTF　temperature　quickly　reaches　steady　state　and　low　final　PCM　temperature　but　has　no　influence　on　steady　state　power.　PCM　initial　state　and　metal　foam　porosity　do　not　affect　the　steady　state　power　and　final　PCM　temperature.　However,　they　affect　the　time　to　reach　steady　state.　Metal　foam　pore　density　has　no　obvious　effect　on　SCD.　SCD　has　more　stable　discharging　performance　than　single　discharging,　especially　when　the　cold　HTF　temperature　is　high.　(c)　2021　Elsevier　Ltd.　All　rights　reserved.