High　energy　consumption　represents　one　of　the　hindrances　in　enabling　large　scale　application　of　membrane　distillation.　In　this　work,　experimental　and　simulation　studies　of　a　double-effect　direct-contact　membrane　distillation　integrated　with　a　single-stage　vapor-compression　heat　pump　(DE-DCMD-HP)　were　carried　out　for　concentrating　tap　water　with　the　aim　to　evaluate　the　energy　saving　of　the　integrated　system.　It　was　found　during　our　experiments　that　an　auxiliary　cooler　must　be　added　to　remove　the　excess　heat　from　HP　to　enable　the　integrated　system　to　reach　the　steady-state　condition.　The　temperature-heat　flux　plots　were　first　utilized　to　analyze　how　HP　and　DE-DCMD　affected　each　other　and　reveal　their　coupling　mechanism.　The　simulation　results　showed　that　the　increase　in　the　first-effect　feed　inlet　temperature,　Tfi,1　and　the　flow　rate,　V　caused　the　thermodynamic　cycle　line　of　refrigerant　shift　to　higher　temperature,　which　led　to　the　increase　of　the　input　power　of　the　compressor　and　the　auxiliary　cooler,　ultimately　affecting　the　water　production　mass　rate,　ṁd,　the　coefficient　of　performance,　COP,　the　gain　output　ratio,　GOR,　and　the　specific　energy　consumption,　SEC.　The　experimental　and　simulation　results　revealed　that　increasing　Tfi,1　and　V　increased　the　permeate　flux　Nh　and　GOR　and　reduced　the　SEC.　The　performances　for　three　different　DCMD　configurations　were　furthermore　evaluated　via　experiments　at　constant　feed　temperature　whereby　the　SEC　decreased　from　2168　kWh·t−1　for　single-effect　DCMD　to　1085　kWh·t−1　for　DE-DCMD　to　257　kWh·t−1　for　DE-DCMD-HP.　©　2024　The　Authors