In this paper, a novel hybrid-connected two-stage liquid dehumidification fresh air (HTLDFA) system by combining CaCl₂ with LiCl aqueous solutions is proposed, in which the ambient air is adopted directly as the regeneration air of CaCl₂ solution and the air pre-dehumidified by part of the strong CaCl₂ is used for regenerating the LiCl solution. In this way, regeneration air of lower humidity for LiCl solution can improve the regeneration efficiency of the LiCl solution and reduce its regeneration temperature. The NTU optimization of main units and the action mechanisms of other fluid parameters on the dehumidification performance of that system are examined. Numerical simulation results show the proposed system is more efficient in utilizing the low-temperature heat sources and the energy and exergy efficiencies can reach about 0.57 and 0.47, respectively. For processing humid fresh air of 0.56 kg/s by using this system, the NTUs of main components are in the optimal range of 2–4 and the flow-rates of two-stage regeneration air are not less than 1.6 kg/s and 0.8 kg/s as well as their driven hot water flow-rates should be more than 1.9 kg/s and 0.8 kg/s. In the HTLDFA system, the water flow-rate of the second-grade cooling tower by using the indoor exhaust air as evaporative air only needs about half that of the first-grade cooling tower of using surrounding air as evaporative air. As for the hybrid-connected mode of CaCl₂ and LiCl solutions, the flow-rate of CaCl₂ solution entering the first-grade dehumidification shares 60 percent of its total flow-rate to achieve the optimal system performance. Performance comparison with the previous two-stage liquid dehumidification system shows that the proposed system has greater efficiency in using low-grade heat sources and achieves higher EER and exergy efficiency.

本文提出了一种新型的混合连接两级液体除湿新风(HTLDFA)系统，将CaCl ₂与LiCl 水溶液结合，直接采用环境空气作为CaCl ₂溶液的再生空气，空气由部分强 CaCl ₂预除湿用于再生氯化锂溶液。这样，对于氯化锂溶液来说，较低湿度的再生空气可以提高氯化锂溶液的再生效率，降低其再生温度。主要单元的NTU优化和其他流体参数对该系统除湿性能的作用机制进行了研究。数值模拟结果表明，该系统利用低温热源的效率更高，能量和火用效率分别达到0.57和0.47左右。使用该系统处理0.56kg/s的潮湿新风，主要部件的NTU在2-4的最佳范围内，二级再生空气的流量不小于1.6kg/s和0.8 kg/s 及其驱动的热水流量应大于 1。9 公斤/秒和 0.8 公斤/秒。在HTLDFA系统中，以室内排风为蒸发空气的二级冷却塔的水流量仅为以周围空气为蒸发空气的一级冷却塔的水流量的一半左右。至于 CaCl 的混合连接模式₂和 LiCl 溶液，进入一级除湿的 CaCl ₂溶液的流量占其总流量的 60%，以达到最佳的系统性能。与之前的两级液体除湿系统的性能比较表明，所提出的系统在利用低品位热源方面具有更高的效率，并实现了更高的 EER 和火用效率。