Application Advances and Prospects of Ejector Technologies in the Field of Rail Transit Driven by Energy Conservation and Energy Transition
Rail transit as a high-energy consumption field urgently requires the adoption of clean energy innovations to reduce energy consumption and accelerate the transition to new energy applications. As an energy-saving fluid machinery, the ejector exhibits significant application potential and academic v...
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| author | Yiqiao Li Hao Huang Shengqiang Shen Yali Guo Yong Yang Siyuan Liu |
| author_facet | Yiqiao Li Hao Huang Shengqiang Shen Yali Guo Yong Yang Siyuan Liu |
| author_sort | Yiqiao Li |
| collection | DOAJ |
| description | Rail transit as a high-energy consumption field urgently requires the adoption of clean energy innovations to reduce energy consumption and accelerate the transition to new energy applications. As an energy-saving fluid machinery, the ejector exhibits significant application potential and academic value within this field. This paper reviewed the recent advances, technical challenges, research hotspots, and future development directions of ejector applications in rail transit, aiming to address gaps in existing reviews. (1) In waste heat recovery, exhaust heat is utilized for propulsion in vehicle ejector refrigeration air conditioning systems, resulting in energy consumption being reduced by 12~17%. (2) In vehicle pneumatic pressure reduction systems, the throttle valve is replaced with an ejector, leading to an output power increase of more than 13% and providing support for zero-emission new energy vehicle applications. (3) In hydrogen supply systems, hydrogen recirculation efficiency exceeding 68.5% is achieved in fuel cells using multi-nozzle ejector technology. (4) Ejector-based active flow control enables precise ± 20 N dynamic pantograph lift adjustment at 300 km/h. However, current research still faces challenges including the tendency toward subcritical mode in fixed geometry ejectors under variable operating conditions, scarcity of application data for global warming potential refrigerants, insufficient stability of hydrogen recycling under wide power output ranges, and thermodynamic irreversibility causing turbulence loss. To address these issues, future efforts should focus on developing dynamic intelligent control technology based on machine learning, designing adjustable nozzles and other structural innovations, optimizing multi-system efficiency through hybrid architectures, and investigating global warming potential refrigerants. These strategies will facilitate the evolution of ejector technology toward greater intelligence and efficiency, thereby supporting the green transformation and energy conservation objectives of rail transit. |
| format | Article |
| id | doaj-art-e819e6f02cb247eeb35ae144be3197b4 |
| institution | Kabale University |
| issn | 1996-1073 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj-art-e819e6f02cb247eeb35ae144be3197b42025-08-20T04:00:53ZengMDPI AGEnergies1996-10732025-07-011815395110.3390/en18153951Application Advances and Prospects of Ejector Technologies in the Field of Rail Transit Driven by Energy Conservation and Energy TransitionYiqiao Li0Hao Huang1Shengqiang Shen2Yali Guo3Yong Yang4Siyuan Liu5Zhan Tianyou College, Dalian Jiaotong University, Dalian 116028, ChinaZhan Tianyou College, Dalian Jiaotong University, Dalian 116028, ChinaSchool of Energy and Power Engineering, Dalian University of Technology, Dalian 116024, ChinaSchool of Energy and Power Engineering, Dalian University of Technology, Dalian 116024, ChinaSchool of Energy and Power Engineering, Dalian University of Technology, Dalian 116024, ChinaZhan Tianyou College, Dalian Jiaotong University, Dalian 116028, ChinaRail transit as a high-energy consumption field urgently requires the adoption of clean energy innovations to reduce energy consumption and accelerate the transition to new energy applications. As an energy-saving fluid machinery, the ejector exhibits significant application potential and academic value within this field. This paper reviewed the recent advances, technical challenges, research hotspots, and future development directions of ejector applications in rail transit, aiming to address gaps in existing reviews. (1) In waste heat recovery, exhaust heat is utilized for propulsion in vehicle ejector refrigeration air conditioning systems, resulting in energy consumption being reduced by 12~17%. (2) In vehicle pneumatic pressure reduction systems, the throttle valve is replaced with an ejector, leading to an output power increase of more than 13% and providing support for zero-emission new energy vehicle applications. (3) In hydrogen supply systems, hydrogen recirculation efficiency exceeding 68.5% is achieved in fuel cells using multi-nozzle ejector technology. (4) Ejector-based active flow control enables precise ± 20 N dynamic pantograph lift adjustment at 300 km/h. However, current research still faces challenges including the tendency toward subcritical mode in fixed geometry ejectors under variable operating conditions, scarcity of application data for global warming potential refrigerants, insufficient stability of hydrogen recycling under wide power output ranges, and thermodynamic irreversibility causing turbulence loss. To address these issues, future efforts should focus on developing dynamic intelligent control technology based on machine learning, designing adjustable nozzles and other structural innovations, optimizing multi-system efficiency through hybrid architectures, and investigating global warming potential refrigerants. These strategies will facilitate the evolution of ejector technology toward greater intelligence and efficiency, thereby supporting the green transformation and energy conservation objectives of rail transit.https://www.mdpi.com/1996-1073/18/15/3951ejectorengine waste heat recoverycompressed air energy storagehydrogen supply systempantograph lift controlenergy-saving technology |
| spellingShingle | Yiqiao Li Hao Huang Shengqiang Shen Yali Guo Yong Yang Siyuan Liu Application Advances and Prospects of Ejector Technologies in the Field of Rail Transit Driven by Energy Conservation and Energy Transition Energies ejector engine waste heat recovery compressed air energy storage hydrogen supply system pantograph lift control energy-saving technology |
| title | Application Advances and Prospects of Ejector Technologies in the Field of Rail Transit Driven by Energy Conservation and Energy Transition |
| title_full | Application Advances and Prospects of Ejector Technologies in the Field of Rail Transit Driven by Energy Conservation and Energy Transition |
| title_fullStr | Application Advances and Prospects of Ejector Technologies in the Field of Rail Transit Driven by Energy Conservation and Energy Transition |
| title_full_unstemmed | Application Advances and Prospects of Ejector Technologies in the Field of Rail Transit Driven by Energy Conservation and Energy Transition |
| title_short | Application Advances and Prospects of Ejector Technologies in the Field of Rail Transit Driven by Energy Conservation and Energy Transition |
| title_sort | application advances and prospects of ejector technologies in the field of rail transit driven by energy conservation and energy transition |
| topic | ejector engine waste heat recovery compressed air energy storage hydrogen supply system pantograph lift control energy-saving technology |
| url | https://www.mdpi.com/1996-1073/18/15/3951 |
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