Pub Date : 2021-09-30DOI: 10.33430/v28n3thie-2020-0028
Rock K C Ho, Zhangyu Wang, Simon Tang, Qiang Zhang
Development of new technology to enhance train operability, in particular during manual driving by real-time object detection on track, is one of the rising trends in the railway industry. The function of object detection can provide train operators with reminder alerts whenever there is an object detected close to a train, e.g. a defined distance from the train. In this paper, a two-stage vision-based method is proposed to achieve this goal. At first, the Targets Generation Stage focuses on extracting all potential targets by identifying the centre points of targets. Meanwhile, the Targets Reconfirmation Stage is further adopted to re-analyse the potential targets from the previous stage to filter out incorrect potential targets in the output. The experiment and evaluation result shows that the proposed method achieved an Average Precision (AP) of 0.876 and 0.526 respectively under typical scenario sub-groups and extreme scenario sub-groups of the data set collected from a real railway environment at the methodological level. Furthermore, at the application level, high performance with the False Alarm Rate (FAR) of 0.01% and Missed Detection Rate (MDR) of 0.94%, which is capable of practical application, was achieved during the operation in the Tsuen Wan Line (TWL) in Hong Kong.
{"title":"Real-time object detection technology in railway operations","authors":"Rock K C Ho, Zhangyu Wang, Simon Tang, Qiang Zhang","doi":"10.33430/v28n3thie-2020-0028","DOIUrl":"https://doi.org/10.33430/v28n3thie-2020-0028","url":null,"abstract":"Development of new technology to enhance train operability, in particular during manual driving by real-time object detection on track, is one of the rising trends in the railway industry. The function of object detection can provide train operators with reminder alerts whenever there is an object detected close to a train, e.g. a defined distance from the train. In this paper, a two-stage vision-based method is proposed to achieve this goal. At first, the Targets Generation Stage focuses on extracting all potential targets by identifying the centre points of targets. Meanwhile, the Targets Reconfirmation Stage is further adopted to re-analyse the potential targets from the previous stage to filter out incorrect potential targets in the output. The experiment and evaluation result shows that the proposed method achieved an Average Precision (AP) of 0.876 and 0.526 respectively under typical scenario sub-groups and extreme scenario sub-groups of the data set collected from a real railway environment at the methodological level. Furthermore, at the application level, high performance with the False Alarm Rate (FAR) of 0.01% and Missed Detection Rate (MDR) of 0.94%, which is capable of practical application, was achieved during the operation in the Tsuen Wan Line (TWL) in Hong Kong.","PeriodicalId":35587,"journal":{"name":"Transactions Hong Kong Institution of Engineers","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48696735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.33430/v28n3thie-2021-0019
Wilson W S Mok, Andrew S W Ng
In this paper, the history of pipejacking works by tunnel boring machines in Hong Kong, their development, selection of design method and tunnel boring machine (TBM), operations, length and alignment of a pipeline, types of techniques to suit different site constraints and ground conditions, and performance of the works are discussed. This paper should be read together with part II, which covers applications, problems encountered, cost and prospects.
{"title":"A perspective of pipejacking works by tunnel boring machines in Hong Kong: part I – development, selection of design, operations and types of techniques","authors":"Wilson W S Mok, Andrew S W Ng","doi":"10.33430/v28n3thie-2021-0019","DOIUrl":"https://doi.org/10.33430/v28n3thie-2021-0019","url":null,"abstract":"In this paper, the history of pipejacking works by tunnel boring machines in Hong Kong, their development, selection of design method and tunnel boring machine (TBM), operations, length and alignment of a pipeline, types of techniques to suit different site constraints and ground conditions, and performance of the works are discussed. This paper should be read together with part II, which covers applications, problems encountered, cost and prospects.","PeriodicalId":35587,"journal":{"name":"Transactions Hong Kong Institution of Engineers","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48033840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.33430/v28n3thie-2021-0020
Wilson W S Mok, Andrew S W Ng
In this paper, application of special techniques such as pipe roof construction, retractable TBM, and rectangular TBM to address site difficulties and constraints is highlighted. Cost and prospects of TBM pipejacking works are discussed. Some observations, including problems encountered and overcome, are also highlighted. This paper should be read together with part I, which covers development, selection of design, operations and types of techniques.
{"title":"A perspective of pipejacking works by tunnel boring machines in Hong Kong: part II – applications, problems encountered, cost and prospects","authors":"Wilson W S Mok, Andrew S W Ng","doi":"10.33430/v28n3thie-2021-0020","DOIUrl":"https://doi.org/10.33430/v28n3thie-2021-0020","url":null,"abstract":"In this paper, application of special techniques such as pipe roof construction, retractable TBM, and rectangular TBM to address site difficulties and constraints is highlighted. Cost and prospects of TBM pipejacking works are discussed. Some observations, including problems encountered and overcome, are also highlighted. This paper should be read together with part I, which covers development, selection of design, operations and types of techniques.","PeriodicalId":35587,"journal":{"name":"Transactions Hong Kong Institution of Engineers","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42714330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-30DOI: 10.33430/v28n2thie-2020-0046
Jeffrey Kwok
Hydrogen is receiving increasing attention for achieving carbon abatement in various sectors, including transport, logistics, thermal engineering and industrial feedstock, etc. Hydrogen can also support distributed power supply that raises national energy security. Both commercial and industrial sectors share a common vision that increasing the cost-effectiveness of renewable hydrogen represents their strategic achievement towards substantial sustainability. This paper explains how hydrogen can play seven roles in the energy transition which include large-scale integration of renewable energy into the power grid, medium for storing and distributing energy across sectors and/or regions, a buffer to increase the electric system resilience and clean fuel for fuel cell vehicles to decarbonise transport. Besides, hydrogen can decarbonise building energy consumption and serve as feedstock using captured carbon. Power Assets Holdings Limited (PAH), a global investor in energy and utility-related business, has identified a hydrogen economy as a strategic vision in its business plan for zero carbon readiness in 2035 and a carbon-free business model in 2050. In this paper, the features and attributes of different hydrogen projects, such as H21 and InTEGRel in the UK and Hydrogen Park in South Australia, are discussed to demonstrate the commercial deployment of hydrogen power.
{"title":"Towards a hydrogen economy – a sustainable pathway for global energy transition","authors":"Jeffrey Kwok","doi":"10.33430/v28n2thie-2020-0046","DOIUrl":"https://doi.org/10.33430/v28n2thie-2020-0046","url":null,"abstract":"Hydrogen is receiving increasing attention for achieving carbon abatement in various sectors, including transport, logistics, thermal engineering and industrial feedstock, etc. Hydrogen can also support distributed power supply that raises national energy security. Both commercial and industrial sectors share a common vision that increasing the cost-effectiveness of renewable hydrogen represents their strategic achievement towards substantial sustainability. This paper explains how hydrogen can play seven roles in the energy transition which include large-scale integration of renewable energy into the power grid, medium for storing and distributing energy across sectors and/or regions, a buffer to increase the electric system resilience and clean fuel for fuel cell vehicles to decarbonise transport. Besides, hydrogen can decarbonise building energy consumption and serve as feedstock using captured carbon. Power Assets Holdings Limited (PAH), a global investor in energy and utility-related business, has identified a hydrogen economy as a strategic vision in its business plan for zero carbon readiness in 2035 and a carbon-free business model in 2050. In this paper, the features and attributes of different hydrogen projects, such as H21 and InTEGRel in the UK and Hydrogen Park in South Australia, are discussed to demonstrate the commercial deployment of hydrogen power.","PeriodicalId":35587,"journal":{"name":"Transactions Hong Kong Institution of Engineers","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46904612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Foreword","authors":"Ni Meng","doi":"10.33430/v28n2foreword","DOIUrl":"https://doi.org/10.33430/v28n2foreword","url":null,"abstract":"","PeriodicalId":35587,"journal":{"name":"Transactions Hong Kong Institution of Engineers","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43713281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-30DOI: 10.33430/v28n2thie-2020-0042
U. Kahangamage, Yi Chen, Quan Zhou, C. Leung
Biogas is considered a sustainable source of energy which is largely untapped owing to its inherent weaknesses such as low thermal performance and potentially harmful emissions. Its thermal performance and emission characteristics can be enhanced through the technique of enriching with higher grade fuel. In this research study, biogas enriched with hydrogen was tested for its emission characteristics. A synthetic biogas identified as BG60 (60% CH4 and 40% CO2) enriched with 20% hydrogen (80%BG60-20%H2) was used for the test. Experiments were carried out for combustion of the enriched gas for a wide range of Reynolds numbers and equivalence ratios. The results indicate that the enriched fuel emits less CO and NOx than commonly used domestic fuel LPG. It also has a better thermal and emission performance than BG60. The low pollutant emissions compared with LPG, use of renewable feedstock for biogas production, and competitive cost may make the blended 80%BG60-20%H2 an attractive sustainable alternative domestic fuel choice for environmentally conscious urban dwellers of modern cities.
{"title":"Can hydrogen enriched biogas be used as domestic fuel? - Part II: Pollutants Emission from Combustion of Biogas/H2/air Fuel Mixture","authors":"U. Kahangamage, Yi Chen, Quan Zhou, C. Leung","doi":"10.33430/v28n2thie-2020-0042","DOIUrl":"https://doi.org/10.33430/v28n2thie-2020-0042","url":null,"abstract":"Biogas is considered a sustainable source of energy which is largely untapped owing to its inherent weaknesses such as low thermal performance and potentially harmful emissions. Its thermal performance and emission characteristics can be enhanced through the technique of enriching with higher grade fuel. In this research study, biogas enriched with hydrogen was tested for its emission characteristics. A synthetic biogas identified as BG60 (60% CH4 and 40% CO2) enriched with 20% hydrogen (80%BG60-20%H2) was used for the test. Experiments were carried out for combustion of the enriched gas for a wide range of Reynolds numbers and equivalence ratios. The results indicate that the enriched fuel emits less CO and NOx than commonly used domestic fuel LPG. It also has a better thermal and emission performance than BG60. The low pollutant emissions compared with LPG, use of renewable feedstock for biogas production, and competitive cost may make the blended 80%BG60-20%H2 an attractive sustainable alternative domestic fuel choice for environmentally conscious urban dwellers of modern cities.","PeriodicalId":35587,"journal":{"name":"Transactions Hong Kong Institution of Engineers","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42753835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-30DOI: 10.33430/v28n2thie-2020-0047
Pradipto Suwidji, H. Y. Chung, Y. Ng
Development of hydrogen utilisation for energy applications has seen promising innovation towards the future prospect of clean and sustainable energy, benefitting various aspects of environmental, social, industrial and energy security. In the APEC region, several economies, such as the USA, China, Australia, Japan and South Korea, have shown interest in the development of hydrogen technology for energy applications. These economies have been devoting effort towards research and development programmes, pilot projects and, up to a certain point, implementing it in their communities. In addition, these economies each have their own tailored hydrogen roadmap or strategy, ensuring a smoother path towards hydrogen development. In this mini-review, we analysed the approaches of three selected economies in the East Asia region towards hydrogen technology, namely China, Japan and South Korea. Each of these economies have their own strategies and priorities towards the application, production and future development of hydrogen technology. This review also analyses the future possibilities for the integration of hydrogen technology into various sectors, as well as various constraints faced by each economy. Therefore, the review might serve as a valuable reference towards the feasibility of future hydrogen technology development in the East Asia and APEC region.
{"title":"Progress in practical hydrogen production and utilisation in East Asia","authors":"Pradipto Suwidji, H. Y. Chung, Y. Ng","doi":"10.33430/v28n2thie-2020-0047","DOIUrl":"https://doi.org/10.33430/v28n2thie-2020-0047","url":null,"abstract":"Development of hydrogen utilisation for energy applications has seen promising innovation towards the future prospect of clean and sustainable energy, benefitting various aspects of environmental, social, industrial and energy security. In the APEC region, several economies, such as the USA, China, Australia, Japan and South Korea, have shown interest in the development of hydrogen technology for energy applications. These economies have been devoting effort towards research and development programmes, pilot projects and, up to a certain point, implementing it in their communities. In addition, these economies each have their own tailored hydrogen roadmap or strategy, ensuring a smoother path towards hydrogen development. In this mini-review, we analysed the approaches of three selected economies in the East Asia region towards hydrogen technology, namely China, Japan and South Korea. Each of these economies have their own strategies and priorities towards the application, production and future development of hydrogen technology. This review also analyses\u0000the future possibilities for the integration of hydrogen technology into various sectors, as well as various constraints faced by each economy. Therefore, the review might serve as a valuable reference towards the feasibility of future hydrogen technology development in the East Asia and APEC region.","PeriodicalId":35587,"journal":{"name":"Transactions Hong Kong Institution of Engineers","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47692139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-30DOI: 10.33430/v28n2thie-2020-0040
Yi Chen, U. Kahangamage, Quan Zhou, C. Leung
Biogas is a renewable energy source widely produced by breakdowns of organic matters in natural environment and industry. However, it is not yet an ideal replacement of fossil fuels because its high CO2 content would deteriorate its thermal performance. To upgrade biogas for possible domestic application, hydrogen enrichment is proposed by adding high-grade hydrogen (H2) to biogas in order to improve its flammability and heating value, and reduce pollutant emission. However, most previous studies on blended Biogas/H2 focus on analysing the effects of H2 fraction and nozzle-to-plate distance on the heat flux profile and flame temperature. No comprehensive study has ever demonstrated the influence of the Reynolds number and equivalence ratio under a wide operating range. In this study, a test rig was built to investigate the effects of the Reynolds number and equivalence ratio on heat flux and thermal efficiency of blended biogas/H2 impinging flame. The blended biogas/H2 consisted of 80% biogas and 20% H2 addition in volume. Biogas was artificially made by 60% CH4 and 40% CO2 (BG60). The Reynolds number ranges from 300 to 1500 and equivalence ratio ranges from 1 to 3. A comparative study was also conducted between pure biogas (BG60) and biogas with 20% H2 enrichment.
{"title":"Can hydrogen enriched biogas be used as domestic fuel? - Part I – Thermal Characteristics of Blended Biogas/H2 Impinging Flames","authors":"Yi Chen, U. Kahangamage, Quan Zhou, C. Leung","doi":"10.33430/v28n2thie-2020-0040","DOIUrl":"https://doi.org/10.33430/v28n2thie-2020-0040","url":null,"abstract":"Biogas is a renewable energy source widely produced by breakdowns of organic matters in natural environment and industry. However, it is not yet an ideal replacement of fossil fuels because its high CO2 content would deteriorate its thermal performance. To upgrade biogas for possible domestic application, hydrogen enrichment is proposed by adding high-grade hydrogen (H2) to biogas in order to improve its flammability and heating value, and reduce pollutant emission. However, most previous studies on blended Biogas/H2 focus on analysing the effects of H2 fraction and nozzle-to-plate distance on the heat flux profile and flame temperature. No comprehensive study has ever demonstrated the influence of the Reynolds number and equivalence ratio under a wide operating range. In this study, a test rig was built to investigate the effects of the Reynolds number and equivalence ratio on heat flux and thermal efficiency of blended biogas/H2 impinging flame. The blended biogas/H2 consisted of 80% biogas and 20% H2 addition in volume. Biogas was artificially made by 60% CH4 and 40% CO2 (BG60). The Reynolds number ranges from 300 to 1500 and equivalence ratio ranges from 1 to 3. A comparative study was also conducted between pure biogas (BG60) and biogas with 20% H2 enrichment.","PeriodicalId":35587,"journal":{"name":"Transactions Hong Kong Institution of Engineers","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42030564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-30DOI: 10.33430/v28n2thie-2020-0039
Bin Wang, Daniel H C Wan, A. T. Cheung, D. Leung, Xiao-Ying Lu, M. Leung
Green production of hydrogen is essential for the development of a hydrogen economy. In this study, the photocatalytic water-splitting technology is developed to harness solar energy for production of renewable hydrogen. Pt-TiO2 nanosheets were fabricated by a facile hydrothermal method, followed by photo-reduction of Pt(acac)2 on B,F-codoped TiO2 with reactive facets. The as-prepared photocatalysts were characterised by transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and UV-vis diffuse reflectance spectroscopy (DRS). The photocatalytic hydrogen production performance was systematically investigated under UV-visible irradiation. The parametric results indicate that the TiO2 nanosheet structure, Pt loading and photocatalyst concentration have significant impacts on the photocatalytic hydrogen production. The highest hydrogen production rate obtained is 5,086 μmol h-1g-1.
{"title":"Green hydrogen production by solar photocatalysis using Pt-TiO2 nanosheets with\u0000reactive facets","authors":"Bin Wang, Daniel H C Wan, A. T. Cheung, D. Leung, Xiao-Ying Lu, M. Leung","doi":"10.33430/v28n2thie-2020-0039","DOIUrl":"https://doi.org/10.33430/v28n2thie-2020-0039","url":null,"abstract":"Green production of hydrogen is essential for the development of a hydrogen economy. In this study, the photocatalytic water-splitting technology is developed to harness solar energy for production of renewable hydrogen. Pt-TiO2 nanosheets were fabricated by a facile hydrothermal method, followed by photo-reduction of Pt(acac)2 on B,F-codoped TiO2 with reactive facets. The as-prepared photocatalysts were characterised by transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and UV-vis diffuse reflectance spectroscopy (DRS). The photocatalytic hydrogen production performance was systematically investigated under UV-visible irradiation. The parametric results indicate that the TiO2 nanosheet structure, Pt loading and photocatalyst concentration have significant impacts on the photocatalytic hydrogen production. The highest hydrogen production rate obtained is 5,086 μmol h-1g-1.","PeriodicalId":35587,"journal":{"name":"Transactions Hong Kong Institution of Engineers","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42804566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}