Humidification and dehumidification (HDH) desalination technology has attracted wide attention in the field of small-scale dispersed fresh water demand, because of its advantages such as simple configuration, low investment, and utilization of low-grade renewable energy and waste heat. In this paper, a heat pump coupled two-stage humidification-dehumidification desalination system with waste heat recovery is proposed, where the waste heat is used to heat the feed seawater of the first-stage humidifier, and the brine leaving the bottom is further heated by the condenser of heat pump and then taken as the feed of the second-stage humidifier, while the evaporator of heat pump is used to recover the heat of humid air from the first-stage dehumidifier. Performance evaluation of the proposed system with various working fluids are conducted regarding the fresh water production m_pw, gained output ratio (GOR), recovery ratio (RR), specific entropy generation s_tot, and unit cost of fresh water production Z_pw, and parametric studies are performed to identify the key operating parameters. Results show that the largest entropy generation occurs in evaporator, followed by the first-stage humidifier and condenser. Taking R22 as the working fluids is corresponding to the largest m_pw, while the lowest Z_pw and s_tot, and the highest GOR are obtained by R600. Higher spraying temperature of the first humidifier T₄ is conducive to improving the m_pw and Z_pw, but leading to a larger s_tot. The GOR increases first and then decreases with the rise of T₄, and the peak value is 4.57 at T₄ = 340.65 K. The mass flow rate ratio of the first stage MR₁ has significant effects on the system performance. When MR₁ is about 3.5, the m_pw, GOR and RR reach the peak. However, the bottom value of Z_pw is 8.74 $/m³ corresponding to the MR₁ of 2.2–2.5. With the increase of compression ratio (CR) of heat pump subsystem, the m_pw, GOR and RR climb up first and then decrease, while Z_pw and s_tot get raised.

加湿除湿（HDH）海水淡化技术以其配置简单、投资少、可利用低品位可再生能源和余热等优点，在小规模分散淡水需求领域受到广泛关注。本文提出了一种热泵耦合余热回收两级加湿除湿海水淡化系统，利用余热加热一级加湿器的进水海水，进一步加热离开底部的卤水通过热泵冷凝器作为二级加湿器的进料，而热泵蒸发器用于回收一级除湿器湿空气的热量。m _pw、增产率 (GOR)、回收率 (RR)、比熵产生s _tot和淡水生产的单位成本Z _pw，并进行参数研究以确定关键操作参数。结果表明，最大的熵产生发生在蒸发器，其次是一级加湿器和冷凝器。以R22为工质对应的m _pw最大，而Z _pw和s _tot最低，GOR最高的是R600。第一加湿器喷洒温度T ₄较高有利于提高m_pw和Z _pw，但导致更大的 s _tot。GOR随着T ₄的升高先增大后减小，在T ₄ = 340.65 K时达到峰值4.57。一级MR ₁ 的质量流量比对系统性能有显着影响。当MR ₁约为3.5时，m _pw、GOR和RR达到峰值。然而，Z _pw的底值为8.74 $/m ³对应于 2.2–2.5 的MR ₁。随着压缩比的增加（CR) 热泵子系统中，m _pw、GOR 和 RR 先上升后下降，而Z _pw和s_没有上升。