The Development and Application of Microchannel Heat Sink on W/Cu Flat-Type Mock-Up

The targets of divertor are subjected to a huge heat load of 20 MW/m2 during the operation of future fusion device. Microchannel cooling technology is an efficient method to dissipate high heat load on the divertor targets. However, the pressure drop of W/Cu flat-type mock-up with traditional rectangular microchannel (RMC) heat sink is particularly large under high flow rate. Here, we proposed a W/Cu flat-type mock-up with optimized microchannels of intermittent open semicircular rectangular (OSCR) architecture to reduce the pressure drop. Simulation study was carried out to examine the pressure drop and maximum temperature on the heating surface of the mock-up. The water was used as a coolant, and the inlet temperature, flow rate, and heat flux on heating surface were set to 298 K, 30 L/min, and 20 MW/m2, respectively. The results demonstrated that the temperature on the W surface of OSCR microchannel mock-up (834.7 K) is comparable with that of traditional RMC mock-up (821.7 K), both of which are much lower than the recrystallization temperature of W (1473 K). However, compared with traditional RMC mock-up (2.9 MPa), the pressure drop of the OSCR microchannel mock-up (0.7 MPa) was reduced significantly, which might be attributed to the increase of the cross-sectional area enabled by the intermittent open microchannels. The present study provides a reference for the optimal design of China Fusion Engineering Test Reactor (CFETR) divertor.