Capturing carbon dioxide (CO₂) from atmospheric air has a great potential to reduce the greenhouse effect, which is of significance to the global campaign against climate change. Due to the extremely low concentration of CO₂ in the air, the current carbon absorption technology has the problems of high consumption of both electrical energy to lead the airflow and water evaporation. In this study, a novel direct air capture (DAC) system, which integrates the conventional natural draft dry cooling towers (NDDCTs) and the current DAC technology, is proposed to lower the operating cost during the CO₂ capture process and enhance the cooling effects of NDDCTs in a thermal power plant as well. The results indicate that the water evaporation during the CO₂ absorption process could create a considerable cooling capacity, which is expected to favor the NDDCTs to reject more heat. Under the design ambient conditions for the NDDCT (30 °C, RH=40%), the thermal performance of the cooling tower can be increased by about 16% with the integration of the DAC absorption process. For a 20 m short NDDCT, the annual CO₂ capture capacity is about 846 tons. By using the cost-free natural draft effect provided by NDDCTs, a great amount of electrical energy can be saved. The mutual benefits could be achieved by integrating both systems.

从大气中捕获二氧化碳 (CO ₂ ) 具有减少温室效应的巨大潜力，这对全球应对气候变化运动具有重要意义。由于空气中CO ₂浓度极低，目前的碳吸收技术存在引导气流和水分蒸发的电能消耗高的问题。在本研究中，提出了一种将传统自然通风干式冷却塔 (NDDCT) 和当前 DAC 技术相结合的新型直接空气捕获 (DAC) 系统，以降低 CO ₂捕获过程中的运行成本并增强冷却效果火电厂中的 NDDCT 也是如此。结果表明，CO 过程中水分蒸发₂吸收过程可以产生相当大的冷却能力，预计这将有利于 NDDCT 排出更多热量。在NDDCT设计环境条件下（30℃，RH =40%），通过集成DAC吸收工艺，冷却塔的热性能可提高约16%。对于 20 m 短的 NDDCT，每年的 CO ₂捕获能力约为 846 吨。利用NDDCTs提供的免费自然通风效果，可以节省大量电能。通过整合两个系统可以实现互惠互利。