{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,5]],"date-time":"2025-11-05T05:48:19Z","timestamp":1762321699490,"version":"build-2065373602"},"reference-count":23,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2018,1,18]],"date-time":"2018-01-18T00:00:00Z","timestamp":1516233600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>Comparative energy and exergy investigations are reported for a transcritical N2O refrigeration cycle with a throttling valve or with an expander when the gas cooler exit temperature varies from 30 to 55 \u00b0C and the evaporating temperature varies from \u221240 to 10 \u00b0C. The system performance is also compared with that of similar cycles using CO2. Results show that the N2O expander cycle exhibits a larger maximum cooling coefficient of performance (COP) and lower optimum discharge pressure than that of the CO2 expander cycle and N2O throttling valve cycle. It is found that in the N2O throttling valve cycle, the irreversibility of the throttling valve is maximum and the exergy losses of the gas cooler and compressor are ordered second and third, respectively. In the N2O expander cycle, the largest exergy loss occurs in the gas cooler, followed by the compressor and the expander. Compared with the CO2 expander cycle and N2O throttling valve cycle, the N2O expander cycle has the smallest component-specific exergy loss and the highest exergy efficiency at the same operating conditions and at the optimum discharge pressure. It is also proven that the maximum COP and the maximum exergy efficiency cannot be obtained at the same time for the investigated cycles.<\/jats:p>","DOI":"10.3390\/e20010031","type":"journal-article","created":{"date-parts":[[2018,1,18]],"date-time":"2018-01-18T12:19:48Z","timestamp":1516277988000},"page":"31","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Energetic and Exergetic Analysis of a Transcritical N2O Refrigeration Cycle with an Expander"],"prefix":"10.3390","volume":"20","author":[{"given":"Ze","family":"Zhang","sequence":"first","affiliation":[{"name":"State Key Laboratory of Multiphase Flow in Power Engineering, Xi\u2019an Jiaotong University, Xi\u2019an 710049, China"}]},{"given":"Yu","family":"Hou","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Multiphase Flow in Power Engineering, Xi\u2019an Jiaotong University, Xi\u2019an 710049, China"}]},{"given":"Francis","family":"Kulacki","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455, USA"}]}],"member":"1968","published-online":{"date-parts":[[2018,1,18]]},"reference":[{"key":"ref_1","unstructured":"Protocol, M. 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