Comparison between various thermal hydraulic tube concepts for the ITER divertor

TLDR: In this article, high heat flux tests on CuCrZr actively water cooled elements were performed with geometric and thermal hydraulic parameters relevant to ITER (International Thermonuclear Experimental Reactor) divertor conditions.

Abstract: High heat flux tests on CuCrZr actively water cooled elements were performed with geometric and thermal hydraulic parameters relevant to ITER (International Thermonuclear Experimental Reactor) divertor conditions. Different types of mock-ups with the same width were tested and compared: double smooth tubes (SM2), swirl tubes (ST2; ST4), annular flow tubes (AF1; AF3) and hypervapotron tubes (HV1; HV3). Analyses of tests were done using the CEA method [1;2] first developed by Sandia Laboratory [ 3 ]. Finite Element calculations were used with a set of correlations in order to express the wall heat flux as a fonction of wall temperature in the convective regime as well as in the subcooled boiling regime (this set is now available in the EUPITER code). Maximum wall heat flux was compared with modified TONG-75 correlation. In terms of ICHF (Incident Critical Heat Flux) and for the same thermal hydraulic conditions, results gave this decreasing order: HV1, HV3, ST2, AF1, ST4, AF3, SM2. Versus lineic pumping power, the previous order was slightly changed: HV1, HV3, ST2, ST4, AF1, SM2, AF3. A typical HV1 result is a 38 MW/m 2 ICHF for 135°C local subcooling, 10 m/s water velocity, 3.5 MPa local pressure, 0.3 MPa/m lineic pressure drop and 380 W/m lineic pumping power.