Experimental investigation on the effect of working fluid charge in a −120 °C turbo-refrigerator
Most existing studies overlooked the impact of the working fluid charge on turbo-refrigerators for ultralow-temperature applications, especially not on the motor-driven turboexpander-compressor (MTEC) based turbo-refrigerators. This study addresses this gap by conducting an experimental study on a n...
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| Format: | Article |
| Language: | English |
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Elsevier
2025-01-01
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| Series: | Case Studies in Thermal Engineering |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2214157X24016629 |
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| author | Shujian Song Xiufang Liu Ze Zhang Zhefeng Wang Shuangtao Chen Yu Hou |
| author_facet | Shujian Song Xiufang Liu Ze Zhang Zhefeng Wang Shuangtao Chen Yu Hou |
| author_sort | Shujian Song |
| collection | DOAJ |
| description | Most existing studies overlooked the impact of the working fluid charge on turbo-refrigerators for ultralow-temperature applications, especially not on the motor-driven turboexpander-compressor (MTEC) based turbo-refrigerators. This study addresses this gap by conducting an experimental study on a newly developed MTEC-based turbo-refrigerator prototype for ultralow-temperature freezing down to −120 °C. The prototype was tested at charge pressures ranging from 249.3 to 438.1 kPa and at different heat loads and at a maintained input power level. Test results indicate the effect of charge pressure on both compressor and expander efficiencies are negligible, whereas both the MTEC's additional efficiency and recuperator effectiveness exhibit a significant increase with increasing charge pressure. The increase in the recuperator effectiveness mitigates the decline in relative Carnot efficiency accounting for no additional losses with increasing charge pressure. Combined with the increased additional efficiency, this results in the net relative Carnot efficiency being only slightly affected by changes in charge pressure. Nevertheless, a slight peak net Carnot efficiency of 9.8 % corresponding to a test charge pressure of 294.6 kPa was noted for the presented prototype. When heat load levels are considered together, changing charge pressure has a greater effect on the relative Carnot efficiency at lower heat loads. |
| format | Article |
| id | doaj-art-ace42fd79fe64ff6a4c62a2c0ef3c565 |
| institution | Kabale University |
| issn | 2214-157X |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Case Studies in Thermal Engineering |
| spelling | doaj-art-ace42fd79fe64ff6a4c62a2c0ef3c5652025-01-08T04:52:43ZengElsevierCase Studies in Thermal Engineering2214-157X2025-01-0165105631Experimental investigation on the effect of working fluid charge in a −120 °C turbo-refrigeratorShujian Song0Xiufang Liu1Ze Zhang2Zhefeng Wang3Shuangtao Chen4Yu Hou5School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, 710049, ChinaSchool of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, 710049, China; MOE Key Laboratory of Cryogenic Technology and Equipment, Xi'an, 710049, China; Corresponding author. School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, 710049, China; MOE Key Laboratory of Cryogenic Technology and Equipment, Xi'an, 710049, ChinaSchool of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, 710049, ChinaSchool of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, 710049, China; MOE Key Laboratory of Cryogenic Technology and Equipment, Xi'an, 710049, ChinaSchool of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, 710049, China; MOE Key Laboratory of Cryogenic Technology and Equipment, Xi'an, 710049, ChinaMost existing studies overlooked the impact of the working fluid charge on turbo-refrigerators for ultralow-temperature applications, especially not on the motor-driven turboexpander-compressor (MTEC) based turbo-refrigerators. This study addresses this gap by conducting an experimental study on a newly developed MTEC-based turbo-refrigerator prototype for ultralow-temperature freezing down to −120 °C. The prototype was tested at charge pressures ranging from 249.3 to 438.1 kPa and at different heat loads and at a maintained input power level. Test results indicate the effect of charge pressure on both compressor and expander efficiencies are negligible, whereas both the MTEC's additional efficiency and recuperator effectiveness exhibit a significant increase with increasing charge pressure. The increase in the recuperator effectiveness mitigates the decline in relative Carnot efficiency accounting for no additional losses with increasing charge pressure. Combined with the increased additional efficiency, this results in the net relative Carnot efficiency being only slightly affected by changes in charge pressure. Nevertheless, a slight peak net Carnot efficiency of 9.8 % corresponding to a test charge pressure of 294.6 kPa was noted for the presented prototype. When heat load levels are considered together, changing charge pressure has a greater effect on the relative Carnot efficiency at lower heat loads.http://www.sciencedirect.com/science/article/pii/S2214157X24016629Turbo-refrigeratorWorking fluid chargeRelative carnot efficiencyTurboexpander-compressorUltralow-temperatureNatural refrigerants |
| spellingShingle | Shujian Song Xiufang Liu Ze Zhang Zhefeng Wang Shuangtao Chen Yu Hou Experimental investigation on the effect of working fluid charge in a −120 °C turbo-refrigerator Case Studies in Thermal Engineering Turbo-refrigerator Working fluid charge Relative carnot efficiency Turboexpander-compressor Ultralow-temperature Natural refrigerants |
| title | Experimental investigation on the effect of working fluid charge in a −120 °C turbo-refrigerator |
| title_full | Experimental investigation on the effect of working fluid charge in a −120 °C turbo-refrigerator |
| title_fullStr | Experimental investigation on the effect of working fluid charge in a −120 °C turbo-refrigerator |
| title_full_unstemmed | Experimental investigation on the effect of working fluid charge in a −120 °C turbo-refrigerator |
| title_short | Experimental investigation on the effect of working fluid charge in a −120 °C turbo-refrigerator |
| title_sort | experimental investigation on the effect of working fluid charge in a 120 °c turbo refrigerator |
| topic | Turbo-refrigerator Working fluid charge Relative carnot efficiency Turboexpander-compressor Ultralow-temperature Natural refrigerants |
| url | http://www.sciencedirect.com/science/article/pii/S2214157X24016629 |
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