Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1732400 | Energy | 2014 | 11 Pages |
•A novel cascading cycle combined with ORC (Organic Rankine Cycle) and CaCl2/BaCl2 adsorption freezer is proposed.•Internal efficiency for power generation of expander is 0.53 when expander inlet pressure is 1 MPa.•Total energy and exergy efficiency for cascading cycle is 10.1%–13.1% and 18.5%–20.3%.•The exergy efficiency for the heat utilization is improved greatly by the cycle.
It is important to improve the heat utilization efficiency for the waste heat as well as the geothermal heat because both of them will exhaust to the environment or flow back to the ground directly after the energy was recovered. In order to achieve that, a novel cascading cycle driven by the low temperature heat source was developed. This cycle featured for the high exergy efficiency for the heat utilization because the energy was utilized two steps by ORC (Organic Rankine Cycle) and CaCl2/BaCl2 two-stage adsorption refrigeration system sequentially with the heat source of higher temperature and lower temperature. For ORC system, a test unit with the fluid of compressed air was established for investigating the internal efficiency of the scroll expander, and the performance of R245fa working fluid was analyzed. For the freezer a CaCl2/BaCl2 two-stage adsorption refrigeration system was set up and tested. Results showed that for the cascading cycle 390–560 W electricity and 1.92–2.7 kW refrigeration can be gotten under the condition of about 22.85–25.1 kW heating power, and correspondingly the total energy and exergy efficiency was 10.1%–13.1% and 18.5%–20.3%, respectively. The cascading cycle improved the exergy efficiency for the heat utilization to 20.4%–29.1%.