Transport for London
Cooling the Tube Programme
Green Park Station -
Borehole Cooling Project
Scheme for using water from boreholes in the royal park to cool platforms at the nearby London Underground station
Design by SKM aka Mouchel, assisted by McLellan and Partners
Heat is extracted from the station by large Air Handling Units on the Piccadilly and Victoria Line
Platforms. The AHUs are served by a closed circuit cold water system from a plant room at ground level where
it is chilled by a heat exchanger connected to boreholes, 130m deep, in Green Park which extract water from
the chalk aquifer below London.
Each borehole has a submersible pump that delivers water at approx. 16°C via pipes running
450 metres across the park to a heat exchanger in the station plant room. After collecting
heat from the station, the water, now at up to 23°C, is piped back to a second set of boreholes
in the park where it returns to the aquifer.
Approximately 800kW of cooling is achieved at a cost of approx 45kW of pumping energy.
The design allows for a second heat exchanger to pre-heat domestic hot water services in
local businesses or hotels. This will not only save the businesses primary fuel but will
also reduce the temperature of the water returning to the aquifer.
The system operates on a flexible time/calendar programme, or under remote supervisory control.
Leak detection systems are installed to shut down the plant and isolate zones to contain
any leaks in the station or the park. The control system provides comprehensive montoring and long term
logging of environmental parameters, plant status data, energy balances and temperatures.
The initial RIBA Stage E/F design was completed in early 2010 and boreholes were drilled. The project
was scheduled for completion under the auspices of the Accelerated Cooling the Tube Programme,
for the London Olympic Games period. Morgan Sindall won the contract and appointed SKM, who engaged
the original design team from McLellan and Partners to modify the M&E design to meet LUL's revised requirements.
The project ran to programme and the system was operational three weeks before the Olympic Games opened.
London Underground subsequently won the Rail Business Award 2012 for Environmental Innovation with this project.
Dual role - Lead Controls and Systems/RAMS Engineer:
- Establishing the system architecture
- Basic design of the PLC based control system
- Specifying the control and instrumentation
- Selection of instruments and cables
- Defining interfaces in detail
- Conducting HAZID meetings, reporting with quantitative risk assessment
- Demonstrating ALARP risk
- Failure Modes and Effects Criticality Analysis (FMECA)
- Reliability analysis of the complete scheme, using AvSim
- Maintainability analysis and report, with tables of periodic and breakdown maintenance requirements
- Detailed cost estimate
- Test specifications
- Site support during construction and commissioning