Many energy intensive, specialist industrial operations depend on chillers for precise control of process cooling and climate management. Combined with fan coil units for indoor heating and cooling, a chiller can also control the climate in a range of work processes and facilities.
Warburtons Bakery in Wednesbury, in the West Midlands, is one such facility. One of the largest bakeries in the UK, Warburtons utilises a number of chillers within their process applications.
A reliable cooling system is clearly business-critical to Warburtons. So when the cost of maintaining and repairing the three ageing York chillers serving the bakery began to escalate Warburtons took the decision to retrofit their chiller system and called on Beswick Refrigeration Services (BRS) to design and install the new system.
In designing the retrofit, BRS had to meet Warburtons’ key objectives for the system to be:
The previous system comprised two separate glycol circuits; Bread Plant 2 served with a water chiller with a capacity of 740kw nominal refrigeration duty and Bread Plant 1 served with two water chillers with a combined capacity of 1014kW of refrigeration duty. This equipment had a history of issues ranging from condenser refrigerant leaks to main PCB failures and compressor problems which necessitated emergency overhauls; all of which resulted in a loss of production on each occasion.
This lack of reliability, combined with ever-tightening legislation which restricts not only the refrigerants that can be used but also lowers the allowable levels of energy efficiency and CO2 emissions, faced BRS with a number of challenges when updating and renewing Warburton’s business-critical climate control system for the coolers.
Using their experience of continually developing innovative and ever-more efficient designs of chilled water systems BRS offered a turnkey project, from redesign to implementation. This helped to ensure that the new chillers would not only meet legislative requirements but would also meet Warburtons’ requirements for energy efficiency and cost-effectiveness.
After considering products from a number of different Chiller manufacturers, BRS and Warburtons chose Daikin as their preferred option. Daikin chillers, which run on R-134a refrigerant, offer high levels of energy efficiency and a three-year warranty.
BRS redesigned the 10” chilled water circuit feeding the Bread Plant coolers 1 and 2 and in the process repositioned the chillers to a more suitable and accessible location. Three new mains power supplies were installed, along with the new chilled water pipework and thermal insulation.
Three new Daikin EWAD water chillers, one EWAD740C (with 740kW of refrigeration duty) and two EWAD530Ds (each with 530kW of refrigeration duty) were installed. BRS designed a bespoke control system using a state of the art HMI (Human Machine Interface). Inverters were added to control the circulation pumps to match accurately the process load and modulate the glycol flow to the process coolers and to again increase the energy efficiency of the plant.
A scheduled and crucial changeover date, with a 12-hour shutdown of production, saw the new chillers commissioned into service smoothly. The installation was carefully implemented and project managed by BRS and Warburtons’ personnel.
With the project completed Warburtons now have a reliable and energy efficient chiller solution which has resulted in a reduction in energy consumption within the first year. Partly this is due to the use of chillers of different sizes which combined with a bespoke temperature control system enable a better turndown of control and partly to the Daikin asymmetric single step compressors which offer excellent part load performance and good load balancing.