Local Govt
CASESTUDY 05
SWANSEA CIVIC CENTRE TURBOMISER
CHILLERS SETS NEW PIPE-RUN RECORD
The new Turbomiser chiller installation at Swansea Civic Centre is believed to have the longest pipe work run ever used for a Turbocor compressor-based project.
Designed and project-managed by the council’s in-house mechanical and electrical design and maintenance section, the project uses two
420kW “split” Turbomisers, installed by Cool-Therm’s Wales branch in the
building’s plant room. They are connected to two air-cooled condensers
some 70m away on the rooftop.
The Turbomisers replaced a pair of conventional, aging Carrier chillers
based on R22. To avoid disruption, it was essential to use some of the
existing refrigeration pipe work.
Dave Blackmore, Cool-Therm director, explains: “The internal building
pipe work runs through library archives, risers and ceilings, and into office
spaces. Replacing it would have been complex and expensive, and would
have caused considerable upheaval for the building.
“The project manager was understandably keen to retain it and replace
the outdoor condensers and chillers in the plant room, resulting in minimal disturbance to the operation of the building.”
This posed a number of design and installation challenges. The original
chillers were based on different pipe sizes to those on the Turbomisers.
Integrating the two required careful design and installation onsite.
In addition, the original dual-circuit Carrier system had four pipes running through the building per chiller, two liquid and two discharge pipes,
compared with Turbomiser’s single circuit. To overcome this, Cool-Therm
designed and manufactured its own bespoke Refnet Y-joint pipe connecting system.
The design for the new chiller system itself posed a particular challenge
due to the complex configuration. It required intensive planning as well
as detailed flow calculations to ensure it would perform efficiently and as
intended.
Dave Blackmore says: “We needed to make sure there was no excessive
pressure drop across any specific component or pipe length, in order to
deliver the correct cooling capacity at the flooded evaporator - rather
than in the pipework.
“This entailed a forensic focus on pipe sizing, vertical and horizontal pipe
lengths. The evaluation had to be right first time, there was no margin for
error. Calculations had to take account of all system pressure drops,
continued over page
The coastal location posed challenges around corrosion protection
The condensers are connected to chillers by pipework 70m in length
“IT ENTAILED A FORENSIC FOCUS ON PIPE SIZING.
THE EVALUATION HAD TO BE RIGHT FIRST TIME,
AS THERE WAS NO MARGIN FOR ERROR.”
DAVE BLACKMORE, COOL-THERM
SWANSEA
PROJECT
Data file
It uses two 420kW “split”
Turbomisers, installed
by Cool-Therm’s Wales
branch. The chillers are
connected to two aircooled condensers some
70m away on the rooftop.
The Turbomisers replaced
a pair of conventional, aging Carrier chillers based on
R22 refrigerant.
Unit 5 , Trubody’s Yard, 121 London Road, Bridgeyate, Bristol BS30 5NA
Email: [email protected] | Tel: 0117 961 006 | Fax: 0117 947 8642 | www.cooltherm.co.uk
Local Govt
CASESTUDY 05
factoring in bends and 45 degree angles, all components and the properties and behaviour of refrigerant via psychrometric charts.”
A further issue arose due to the oil-free nature of the Turbomiser chillers,
which run on magnetic bearings. The previous chillers, based on reciprocating compressors, used conventional lubricant and therefore pipe work
incorporated oil traps. This meant that all oil residues in existing pipe
work had to be flushed out and thoroughly cleaned prior to installation.
“We couldn’t allow any oil to remain in the system. This required removing all the oil traps and blowing the pipes out with oxygen-free nitrogen
(OFN). As a back-up, we also ran a separate recovery rig with an oil accumulator in series with the chiller to catch any residual oil that remained
after treatment with OFN.”
The existing chillers were disconnected and dismantled in situ, and taken
out in manageable sections through public access areas in the civic centre. The Turbomisers were transported to the plant room in the same way
Dave says: “Fortunately, Turbomiser chillers are fully modular so we
were able to break them down, bring them in into the building in ‘kit
form’ and rebuild them insitu in the plant room.”
Cool-Therm fitted new refrigerant leak detection and emergency extract
ventilation in the plant room to comply with current F-Gas regulations.
The plant room also features a fully integrated compressor input/output
board with an RS232 connection to a laptop or building management
system. All the controls can be integrated with the Turbocor compressors.
A Turbocor compressor on one of the two Turbomiser machines
Corrosion protection
Given the coastal location, the specification of the aluminium condensers
required special attention in order to safeguard them against maritime
conditions and potential corrosion.
The micro-channel condensers are designed to reduce refrigerant charge
while, at the same time, increasing the effectiveness heat exchange.
However, Swansea Civic Centre is located just 20m from the seafront
and is constantly exposed to salt and sand and corrosive sea breezes. To
protect against this, the micro-channel condensers were treated with an
anti-corrosion coating to protect them from the elements.
“The client wanted an extended warranty on the system. To achieve this
given the location, we ensured that condensers were galvanised and then
epoxy coated and that copper pipe work was PIB (pipe insulation billet),
covered with galvanised wrapping on top of that. This ultra-corrosion
resistant treatment enables the equipment to withstand the effect of the
sea air and coastal weather conditions.”
Turbomiser chillers are based on the Turbocor oil-free compressor, which
uses virtually frictionless magnetic bearings to produce the most energy
efficient product of its type on the market. Turbomiser chillers reduce
energy costs by up to 50 per cent compared with traditional chillers.
The built-in control panel on the front of a Turbomiser chiller
“TURBOMISER CHILLERS ARE FULLY MODULAR,
SO WE WERE ABLE TO BREAK THEM DOWN AND
BRING THEM INTO THE BUILDING IN KIT FORM.”
DAVE BLACKMORE, COOL-THERM
TURBOMISER
CHILLER
In addition to dramatically
lower energy use, the main
benefits of Turbomiser
chillers are reduced refrigerant leakage; less maintenance due to the oil-free
design; light weight (the
compressor weighs 125kg
compared with 600kg for
traditional compressors);
excellent part load efficiency; quiet operation, and
reduced starting current of
around 5Amps compared
with some 600Amps for
conventional compressors.
Unit 5 , Trubody’s Yard, 121 London Road, Bridgeyate, Bristol BS30 5NA
Email: [email protected] | Tel: 0117 961 006 | Fax: 0117 947 8642 | www.cooltherm.co.uk