Indirect integration of a thermal–mechanical heat pump with a humidification-dehumidification desalination unit

• Published in: Applied thermal engineering 2023-07, Vol.230, p.120852, Article 120852
• Main Authors: Ghiasirad, Hamed, Baris, Towhid Gholizadeh, Javanfam, Farzin, Rostamzadeh Kalkhoran, Hadi, Skorek-Osikowska, Anna
• Format: Article
• Language: English
• Subjects: Absorption-compression refrigeration; Exergo-economics; Geothermal heat source; HDH desalination; Steam extraction
• ISSN: 1359-4311
• DOI: 10.1016/j.applthermaleng.2023.120852

•68.5% of the vapor should be recirculated from the evaporator to the condenser.•The freshwater cost and COP are far better than those of two recent studies.•EUF and exergy efficiency reached 6.961 and 11.58%. Many previously developed integrated desalination and heat pump cycles have been observed to consume a significant amount of direct electricity supply, raising concerns about their cost effectiveness. To address this issue, this study has modified the performance and cost metrics of the double-effect absorption heat pump cycle combined with a humidification-dehumidification desalination system in terms of configuration. The novelties of the present study are to preheat seawater for desalination utilizing the waste heat of the absorption chiller and to design a doble-effect hybrid thermal–mechanical heat pump. Thermodynamic and thermoeconomic tools were applied to the system. The proposed cooling/desalination system was found to produce 23.23% more freshwater and 47.7% more cooling than a traditional combination. As a result, the current cogeneration unit achieved an energy utilization factor (EUF) of 6.96, which is approximately 17.89% higher than the conventional configuration. Compared to the base case, optimal steam extraction showed a significant improvement of 27.23% in exergy efficiency. Regarding cost metrics, the cost of freshwater was determined to be 2.051 $/m3. As a result, the humidifier has the highest attribution to the overall exergy destruction at 8.98 kW, which represents approximately 16.5% of the total exergy destruction rate.