A power and cooling cogeneration system using mid/low-temperature heat source

• This paper proposed an ammonia–water based power/cooling cogeneration system using waste heat.
• Waste heat is utilized in a cascade way in power and cooling generation subsystems.
• The condensation heat of turbine exhaust vapor is recovered by the refrigeration subsystem.
• The interactions between the power and cooling generation subsystems are investigated.
• Experimental results on the cooling generation subsystem are presented.

An ammonia–water based system for power and cooling cogeneration using mid/low-temperature heat source is proposed and investigated in this study. The proposed system consists of a Rankine cycle and an absorption refrigeration cycle. The high-temperature portion of waste heat is used for power generation, whereas the low-temperature part is used for refrigeration. In addition, the exhaust heat of the power subsystem is recovered by the refrigeration subsystem. Simulation results show that the equivalent heat-to-power and exergy efficiencies of the proposed cogeneration system can reach 18.6% and 42.0%, respectively. Compared with separate power and refrigeration systems, the proposed system consumes 17.1% less heat with the same output. The effect of turbine exhaust vapor temperature on system performance is investigated. An experimental rig of an absorption refrigeration system with a cooling capacity of 15 kW was built and tested. The proposed system was found to be capable of utilizing mid/low-temperature heat source more efficiently.