FRANCE: A Danfoss Optyma Plus Inverter packaged condensing unit installed in a hypermarket bakery is said to highlight some of the benefits of this recently introduced capacity modulation solution.
The European launch of the inverter variable speed technology version of Danfoss’ Optyma Plus packaged condensing units was announced last week. It is said to offer considerable energy savings and is described as being perfectly suited to the needs of convenience stores and service stations.
The pilot installation in question was made 18 months ago at an in-store bakery in a hypermarket that is part of an internationally known chain. The hypermarket is based in a small popular tourist destination in southern France. Production of bread and baguettes varies very significantly, from 1,000 to 2,000 baguettes per day depending on the season. The bakery also offers a wide variety of other breads, as well as pizzas, quiches and pies to take away.
The wide range of produce means frequent cycle changes depending on production requirements, quick thawing or accelerated fermentation of doughs with different rising temperatures. Each stage of bread fermentation – first fermentation, shaping and second fermentation – requires very specific temperatures. In addition, the bakery process produces a large amount of corrosive gas and dust.
These constraints led Bernard Abrax, manager of Tessonnière, a commercial and industrial refrigeration and air conditioning specialist, to install a standalone refrigeration circuit for the bakery, on the roof of the supermarket above the retarder/proofers.
“We are familiar with variable speed in commercial refrigeration, but in larger systems,” explains Bernard Abrax. “In this set of three proofing cabinets and one retarder/proofer, capacity modulation is very much a necessity. We have huge variations in load, with one cabinet operating cold, another hot and another warm, and this changes throughout the day. Unlike other modulation systems, and particularly electromechanical systems, with the Optyma Plus Inverter we have no short cycle, modulation really ranges from 30 to 100% of the load, and all with lower electricity consumption,” he adds.
“The bakery is a very interesting application for the Optyma Plus Inverter. Condenser units of this kind will probably mostly be installed in refrigerated cabinets in convenience stores or cold rooms. The benefit is just as significant for ice production. The temperature of the incoming water can vary massively, depending on the ambient temperature and the length of the supply pipes. With capacity modulation it is possible to adapt the cooling capacity to ambient conditions and to ensure the yield, as well as the quality and quantity, of the ice produced.”
“In supermarkets and hypermarkets, communication via the modbus Optyma controller makes it possible to remotely monitor how the unit is functioning and to track its power consumption. As well as being easy to install and programme, it will also enable us to optimise the sizing of future installations.”
“While the technology is very widely used in air conditioning, its use in commercial refrigeration is still very limited for low capacities of 3 to 20kW, where usage conditions are more complicated to get to grips with,” commented Erik Roels, Danfoss’ regional business development manager.
“We took the time to develop a dedicated refrigeration unit, by combining our know-how in condensing unit design and our expertise in variable speed. This unit is highly versatile and perfectly suited to the needs of convenience stores and service stations, where several cabinets can be connected simultaneously. It offers considerable energy savings compared with other technologies and a return on investment in lower than two years in terms of installation, running and maintenance costs, both for the installer and for the end user.” added Erik Roels.