Management of Vehicle Emissions from Tunnels

1
Management of Vehicle Emissions from Tunnels

• Benchmarking SH20 Waterview with international
  practice

2
Report scope

• Response to public concerns about air quality
• Transit board resolution
• Focus on 3 countries
• Australia, Norway and Japan

3
Tunnel Ventilation

• Objectives
• maintain visibility inside the tunnel
• maintain acceptable air quality outside the
  tunnel
• save lives in the event of a fire
• Conventional approach
• Natural vs mechanical
• Ventilation fans introduce fresh air, then
  release the air to the atmosphere

Jet fans installed on tunnel roof 
4
Management Options

• Dispersion
• Ventilation exhausts
• Portals
• Treatment systems
• Electrostatic precipitators (reduce dust and
  particulate levels)
• NOx removal technologies
• No technology available for CO removal
• Traffic management
• Steady flow of traffic
• Speed restrictions

5
ESPs

• Remove particles between 1-10 microns
• Operated on as needed basis
• Removal efficiency in road tunnels varies 50-90

Ultrafine Particle Size (nm) decreasing
Time/date
6
AUSTRALIA

• AQ approvals for Sydney tunnels are some of the
  strictest in the world
• All recent tunnels mechanically ventilated with
  dispersion via vent exhausts.
• ESP is being trialled in M5 East

M5 East Tunnel, Sydney
7
Australian Examples

• Sydney
• Cross City Tunnel 2.1 km
• M5 East 4.5 km
• Lane Cove 3.6 km
• Brisbane
• North South Bypass Tunnel 4.8km
• Airportlink 5.3km
• Melbourne
• Eastlink 1.6km
• Citylink 2 tunnels 1.6km and 3.8 km

Cross City Tunnel, Sydney
North South Bypass, Brisbane
8
JAPAN

• High proportion of diesel vehicles
• 30 in Tokyo.
• 50 in rural areas.
• Largest number of ESPs installed in the world
  still only 0.5 of 8000 tunnels.
• The majority of these are for poor visibility
  inside the tunnels
• Only 7 of these were for external air quality

Wan Aqualine, Tokyo Bay
9
Japan Examples

• Kyoto Tennozan tunnel 1.9km
• 2 ventilation exhausts fitted with ESPs
• 47 heavy vehicles
• Since the early 1980s traffic congestion at both
  exits of the tunnel a problem
• Tokyo Yamate 11 km
• 9 ventilation exhausts
• ESP and NO2 treatment installed at 3 locations

Tennozan . Kyoto
Yamate, Tokyo
10
Japan Example Tokyo Wan Aqualine

• 9.6 km long
• Longest underwater tunnel for cars
• 2 vent exhausts on man made islands
• ESPs installed, fabric filter bag technology
  discontinued

11
NORWAY

• 20 of fleet is diesel
• Studded snow tyres contribute to high levels of
  particulate
• lt1 of 1000 tunnels have treatment installed
• Most ESPs installed to increase visibility inside
  the tunnels.

Hell Tunnel, Trondheim
12
Norway Examples

• Oslo Festning Tunnel, 1.8 km
• ESP no longer operated
• Trondheim Hell Tunnel, 3.9 km
• ESPs were installed and later abandoned
• Oslo Ekeberg, 1.5 km
• ESPs installed for internal AQ

Festning Tunnel, Oslo
Ekeberg Tunnel, Oslo
13
Norway Examples - Laerdal Tunnel

• 24.5 km long
• NO2 removal technology and ESP

14
Findings

• Dispersion via portals or ventilation exhaust is
  most common method for managing emissions
• Dispersion techniques are effective for all
  contaminants
• Few tunnels in the world use treatment (lt1)
• The vast majority use treatment for in-tunnel
  visibility
• Technology used for limited periods, some has
  been abandoned due to limited effectiveness
• SH20 Waterview meets current international
  practice

15
SH20 Waterview