©　2018　Elsevier　Ltd　Water　vapor　compression　is　a　key　technology　that　greatly　affects　system　performance　in　heat　pump　and　mechanical　vapor　compression/recompression　applications.　In　this　paper,　two-stage　water　vapor　compression　methods　(cascaded　centrifugal　compressors　and　combined　centrifugal　and　twin-screw　compressors)　were　proposed　and　studied　to　deal　with　the　water　compression　process　with　large　suction　volume　flow　rates　and　high　compression　pressure　ratios.　A　mathematical　model　was　developed,　and　the　thermal　characteristics,　achievable　volume　flow　rate　and　saturation　temperature　rise　of　the　two　water　compression　systems　were　presented.　The　two-stage　compression　process　using　cascaded　centrifugal　compressors　was　found　to　be　better　for　applications　with　total　saturation　temperature　rise　lower　than　40　°C.　The　two-stage　compression　process　using　combined　centrifugal　and　twin-screw　compressors　was　found　to　satisfy　applications　with　a　saturation　temperature　rise　as　high　as　80　°C.　Further　investigation　showed　that　the　second　method　could　deliver　a　suction　volume　flow　rate　of　1418　m3/min　with　a　suction　vapor　temperature　of　50　°C　using　a　current　market-available　twin-screw　compressor　with　a　capacity　of　600　m3/min.　The　performance　of　the　combined　systems　was　largely　affected　by　the　pressure　ratio　and　the　compressor　efficiency,　system　suction　vapor　temperature,　and　total　vapor　saturation　temperature　rise.　The　analyses　showed　that　the　combined　system　had　high　energy　efficiency　above　3.4　under　all　studied　working　conditions.