This　paper　presents　the　heat　transfer　of　subcooled　water　in　swirl　flow　under　high　heat　fluxes　with　respect　to　the　heat　removal　technologies　for　the　divertors　in　the　International　Thermonuclear　Experimental　Reactor　(ITER).　The　experiments　were　conducted　in　a　vertical　circular　tube　that　was　heated　uniformly　with　a　large　AC　power　supply.　A　twisted　tape　with　a　twist　ratio　of　2　or　4　was　inserted　into　the　circular　tube　to　induce　the　swirl　flow.　The　test　parameters　were　as　follows:　heat　flux　q　=　5-19.5　MW/m(2);　system　pressure　P　=　3,　4.2,　5　MPa;　mass　flux　G　=　6000,　8000,　10,000　kg/(m(2)　s);　and　inlet　bulk　temperature　T-b.i=　50-200　degrees　C.　The　heat　transfer　coefficients　and　boiling　curves　are　obtained　from　single-phase　forced　convection　to　fully　developed　nucleate　boiling.　The　influences　of　mass　flux,　heat　flux,　system　pressure,　thermodynamic　quality,　and　inlet　subcooling　on　heat　transfer　are　discussed　in　detail.　Special　attention　is　paid　to　the　effect　of　the　twisted　tape　on　subcooled　heat　transfer.　More　importantly,　a　wide　set　of　heat　transfer　correlations　are　evaluated　on　the　basis　of　our　experimental　data,　and　relevant　recommendations　for　engineering　applications　are　made　according　to　their　prediction　accuracies.　(C)　2015　Elsevier　Inc.　All　rights　reserved.