Simulation on energy use for mechanical ventilation and air-conditioning (MVAC) systems in train compartments

Chow, Wan Ki; Yu, Philip C.H.

doi:10.1016/s0360-5442(99)00061-4

Cited by 13 publications

(4 citation statements)

References 3 publications

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“…Thus, demand-controlled ventilation based on the concentration of CO2 (i.e., according to the actual occupation of the vehicle) guarantees that no energy is wasted in conditioning unnecessary fresh air intakes [111][112][113], which may imply energy savings of up to 55% [114]. In this sense, reducing avoidable door openings may also play an important role [115].…”

Section: Rolling-stock-related Measures For Service Modementioning

confidence: 99%

A systems approach to reduce urban rail energy consumption

González-Gil

Palacín

Batty

et al. 2014

Energy Conversion and Management

393

202

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There is increasing interest in the potential of urban rail to reduce the impact of metropolitan transportation due to its high capacity, reliability and absence of local emissions. However, in a context characterised by increasing capacity demands and rising energy costs, and where other transport modes are considerably improving their environmental performance, urban rail must minimise its energy use without affecting its service quality. Urban rail energy consumption is defined by a wide range of interdependent factors; therefore, a system wide perspective is required, rather than focusing on energy savings at subsystem level. This paper contributes to the current literature by proposing an holistic approach to reduce the overall energy consumption of urban rail. Firstly, a general description of this transport mode is given, which includes an assessment of its typical energy breakdown. Secondly, a comprehensive appraisal of the main practices, strategies and technologies currently available to minimise its energy use is provided. These comprise: regenerative braking, energy-efficient driving, traction losses reduction, comfort functions optimisation, energy metering, smart power management and renewable energy micro-generation. Finally, a clear, logical methodology is described to optimally define and implement energy saving schemes in urban rail systems. This includes general guidelines for a qualitative assessment and comparison of measures alongside a discussion on the principal interdependences between them. As a hypothetical example of application, the paper concludes that the energy consumption in existing urban rail systems could be reduced by approximately 25-35% through the implementation of energy-optimised timetables, energy-efficient driving strategies, improved control of comfort functions in vehicles and wayside energy storage devices.

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Section: Rolling-stock-related Measures For Service Modementioning

confidence: 99%

A systems approach to reduce urban rail energy consumption

González-Gil

Palacín

Batty

et al. 2014

Energy Conversion and Management

393

202

View full text Add to dashboard Cite

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“…Mandatory installation of an energy use meter and a carbon dioxide meter might be required to monitor key parameters. Transient carbon dioxide concentrations [28,29] measured can then be used to deduce ventilation rate from equation ( 1) derived from the well-mixed model in a later section.…”

Section: Ventilation Requirementsmentioning

confidence: 99%

“…Earlier observations on ventilation inadequacy in a train car with passengers trapped inside [28,29] suggested that carbon dioxide concentration can give an estimation on ventilation rate based on the well-mixed model equation (1). Carbon dioxide concentration will be very high for inadequate ventilation rate.…”

Section: Control Schemementioning

confidence: 99%

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Ventilation Requirements and Recommendations for Controlling SARS-CoV-2 and Variants Outbreaks in Indoor Gathering Places with Close Contact

Chow

2022

Preprint

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Unexpected rapid infection involving SARS-CoV-2 variant Omicron known as the fifth wave of outbreak occurred since early January 2022 in Hong Kong. Almost 1.2 million citizens were infected in three months. Ventilation provisions in some gathering places with close contact such as restaurants were found to be lower than requirements, believed to be one of the main causes of transmission in these indoor spaces. At the end of the fifth outbreak in mid-May 2022, group infections were still found in several such gathering places including restaurants and pubs due to inadequate ventilation provisions. There are worries about triggering the sixth wave of outbreak. Key points related to ventilation requirements in such gathering places are discussed in this paper. Adequate ventilation of 6 air changes per hour minimum must be provided to avoid direct air transmission of virus. Indoor aerodynamics induced by ventilation system must be considered too. However, it is difficult to measure ventilation rate quickly and accurately. A control scheme on virus outbreaks is proposed on installing mechanical ventilation energy use meters and carbon dioxide sensors for checking ventilation provisions adequacy quickly.

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