Feasibility research on the novel experimental solar-assisted CO2 based Rankine cycle integrated with absorption refrigeration

KIZILKAN Ö., Yamaguchi H.

Energy Conversion and Management, vol.205, 2020 (SCI-Expanded, Scopus) identifier

  • Publication Type: Article / Article
  • Volume: 205
  • Publication Date: 2020
  • Doi Number: 10.1016/j.enconman.2019.112390
  • Journal Name: Energy Conversion and Management
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Agricultural & Environmental Science Database, Applied Science & Technology Source, CAB Abstracts, Communication Abstracts, Compendex, Computer & Applied Sciences, Environment Index, INSPEC, Pollution Abstracts, Veterinary Science Database, Civil Engineering Abstracts
  • Keywords: Absorption refrigeration, CO2, Exergy analysis, Power generation, Solar energy
  • Isparta University of Applied Sciences Affiliated: Yes

Abstract

In this paper, a feasibility analysis of the novel solar-assisted transcritical carbondioxide (tCO2) based Rankine cycle (RC) with an absorption refrigeration system (ARS) is performed. The experimental investigations are conducted on the test rig of the solar-assisted tCO2-RC for a typical day in the spring season. The unique experimental facility consists of evacuated tube type solar collectors, a high-temperature heat exchanger, a low-temperature heat exchanger, and a pump. In addition, an expansion valve is employed instead of the turbine in order to simulate the turbine operation. The proposed ARS is a single-stage type, and it is supposed to be driven by the rejected thermal energy from the experimental RC cycle. The performance of the integrated system is analyzed in terms of energy and exergy. The ARS analysis is made for water-lithium bromide (H2O-LiBr) and ammonia-water (NH3-H2O) refrigerant pairs for comparison purposes. According to the results, the power generation rate of CO2 based RC reaches up to 0.385 kW. The ARS working with H2O-LiBr presents higher refrigeration capacity with 1.413 kW while the energy and exergy efficiencies of the integrated power-refrigeration system are determined as 29.62% and 5.36% respectively. For the integrated system with NH3-H2O, the energy efficiency is 21.51% and the exergy efficiency is 4.99%. From the results, it is concluded that the ARS working with H2O-LiBr can be successfully integrated with the solar-assisted tCO2-RC for sustainable power generation and refrigeration applications. Future research should, therefore, concentrate on integrating an actual ARS with the experimental power cycle.