Socatop

Client

Socatop (Société de Construction de l'Autoroute de Traversée de l'Ouest Parisien), is a group formed by Cofiroute's shareholding companies: Vinci, Colas, Eiffage.

Among the world's leading road building and public construction companies, these major French companies have pooled their human, technical and financial resources to conduct the largest underground construction project currently underway in Europe.

Established in 1970, Cofiroute is a private highway contractor in France. It has already built and now operates nearly 1000 kilometres of highway.

The A86 West is one of the largest underground highway construction projects currently underway in Europe. It is incredibly discrete for a project of its size, largely because 90% of the route is underground.

It is the TBM that enables such a large scale project to be so discrete. This giant machine, a key project component, works deep under the subsoil to drill out circular galleries of over 10 meters in diameter.

Objective

• To cool hydraulic circuits and air compressors of tunnel boring machine (TBM)
• To dissipate 2,500 kW when cooling 180 m³/hr water from 35°C to 23°C, in a design ambient of 19°C wet bulb

Solution

Customised dedicated open circuit water cooling system

The system comprised:

• Storage container, 12m x 2.4m x 2.6m high, complete with vertical partition one third along the length of the container with access to the smaller partitioned section via a side access door. Access to the larger partitioned area is via two large doors at the end of the container. The container was painted to RAL 6003

The larger partitioned section contains:

• 2 Sectional Water Storage Tanks, 1 storing cooled water returning from the 'roof-mounted' cooling tower, 1 storing heated water returning from the process. Complete with level switches giving high and low indications and a thermostatic control valve and sensor to control mixing of 10°C water when required

The smaller partitioned section contains:

• 2 Hot Water Pumps fitted with 2 'IP65' 22.0 kW pumps (1 duty, 1 standby). Each pump delivers the required system flow rate plus approximately an additional 15%, at a pressure differential of 2.5 bar measured at the pump
• Wall mounted Electrical Control Panel
• 2 Open Circuit Cooling Towers, each mounted on the roof of the container. The towers were painted to RAL 6003

Result

• Socatop saves money whilst conserving natural resources and reducing environmental impact
• Efficient temperature control, Open Circuit Cooling Towers with centrifugal fans deliver fully rated thermal performance over a wide range of flow and temperature requirements
• Low sound, centrifugal fans minimise sound levels
• Low energy consumption, evaporative cooling equipment minimises the energy consumption of the entire system as it provides lower operating temperatures
• Easy maintenance
• Reliable year-round operation, the fans, motor and drive systems are located outside of the moist discharge air stream, protecting them from moisture, condensation and icing hence allowing a safe year round operation

Endorsement

Socatop Plant Manager said: "The Tunnel Boring Machine is operated round-the-clock, boring is continuous. As a result of this it was imperative that we acquired efficient and reliable cooling equipment to enable this continuous and efficient operation. We approached Stadco Cooling as they have an excellent reputation; they are dependable and have extensive experience of designing cooling systems across a diverse range of sectors."

He added: "They came up with the most economical and cost effective solution and delivered on time."