Integration of different organic Rankine and Kalina cycles with compressed refrigeration cycle to reduce the power consumption: a comparative study

The compressed refrigeration cycle (CRC) is one of the popular cooling production cycles, which has important advantages. However, it has high power consumption and significant waste heat. Due to the arising costs of power consumption, the generated heat is very valuable. Moreover, this heat is good enough to be utilized as the heat source of the Organic Rankine cycle (ORC) and Kalina cycle (KC) which are capable of using low-temperature heat sources. In the present work, to improve this integration, the effects of configuration changes for integrating CRC with ORC equipped with a regenerator (system1), ORC equipped with turbine bleeding (system2), KC equipped with a regenerator (system3), and KC equipped with a flash vessel and turbine (system4) are presented. The proposed systems are examined and compared from energy, exergy, economics, environmental, and exergoenvironmental perspectives. If System2 is used, the coefficient of performance is improved 2.05 %, i.e. 14.01 MWh/year and 3.96 ton/year reduction in the power consumption and the CO2 emissions compared to CRC. On the other hand, exergy efficiency and exergoenvironmental impact factor are improved by 16.07 % and 2.46 %, respectively. Meanwhile, the payback period of system2 is obtained as 2.6 years. To find the best system, a scoring method is performed and it is concluded that system2 achieves a higher score even if the priorities change.