A Laboratory Scale Heat Pipe Condenser with Sweating Boosted Air Cooling

Abstract Air-cooled condensers (ACCs) in thermal power plants are more competitive than the water-cooled condensers (WCCs) in addressing the global water crisis. The state-of-art ACCs need emerging heat transfer enhancement technologies, so hybrid wet/dry cooled condensers (HCCs) are employed to compensate for the low efficiency of ACCs. We propose a heat pipe air-cooled condenser (HPACC) to overcome the high capital and operating cost of traditional HCCs. HPACC combines the proven heat pipe technology with a novel sweating-boosted air-cooling strategy. Its architecture is similar to the most efficient once-through WCCs but replacing conventional water tubes with high-performance heat pipes. A lab-scale HPACC is built by scaling down the prototype of the proposed HPACC. This study evaluates the heat transport and rejection process within a HPACC. The thermal performance of HPACC is characterized under various heat loads and air velocities, and the sweating-boost effects on the HPACC are investigated. Our study shows that a saturated heat load on the HPACC exists under given air-cooling conditions. The minimum overall thermal resistance of HPACC is 4.7439×10-2 K/W achieved at an effective heat load of 1606.40 W with an air velocity of 3.0 m/s. Air cooling is further boosted by the sweating process on the fined surface integrated with superwetting copper hydroxyl nitrate wicks (Cu2(OH)3NO3). It demonstrates that HPACC with a sweating-boosted air cooling (HPACC-SB) significantly improves the total effective heat load by 172.17% and reduces the overall thermal resistance by 64.27%. The proposed HPACC is promising in replacing current cooling equipment of thermal power plants. Moreover, substantial water saving will help alleviate the water crisis facing the world.