SWEDEN: Alfa Laval continues the expansion of its brazed plate heat exchanger portfolio with, what it claims, is the first dedicated condenser for use with R290 (propane).
The CB24 was engineered for low refrigerant charge combined with increased thermal efficiency. The manufacturer sees the CB24 creating opportunities to improve sustainability for commercial refrigeration, ground source heat pumps, satellite systems for tap water and more.
While the use of R290 has grown considerably, its flammability presents practical and technical challenges with restrictions on usage and maximum refrigerant charge.
“The aim of CB24 has been to solve these challenges for some of the heating and cooling duties where the ability to use R290 will become increasingly critical,” said Fredrik Ekström, Alfa Laval’s president for business unit brazed and fusion bonded heat exchangers.
“We did this by adapting some of the unique innovations Alfa Laval has developed through our long experience in these applications. This has given us a dedicated condenser that successfully accommodates the refrigerant charge limitations of working with propane, without sacrificing thermal performance.”
A key element of the development of the CB24 was Alfa Laval’s FlexFlow, a patented plate design technique that allows for channel asymmetry custom-tailored to fit the media in a question. FlexFlow is said to make it possible to increase turbulence and optimise pressure drop according to a particular application. According to Alfa Laval, the CB24 can therefore provide highly efficient heat transfer while at the same time operating on a propane refrigerant charge that is lower than previously possible.
“This means, for example, that CB24 easily meets the strict regulations for some commercial refrigeration applications, which limit a propane charge to 500g,” explains Fredrik Ekström.” “But it goes further than that. CB24 can even fulfil the much more stringent requirements for GSHPs, which in Europe are limited to a ref charge of just 150g.”
Another important feature for CB24 has been Alfa Laval’s PressureSecure design, which optimises the relationship between thermal, mechanical and material properties to support pressure loads associated with R290. Alfa Laval maintains that this produces a more robust heat exchanger, particularly around the port areas, which can be highly susceptible to pressure-related fatigue problems.
“With CB24, the ability to use propane with a reduced ref charge is only half the story,” Fredrik Ekström says. “The possibility to improve thermal efficiency will also create new opportunities for energy savings for many of our customers.”
He cites the example of a commercial refrigeration application involving vertical shelves without a door. Here, he maintains, one CB24 condenser would be adequate where previously up to three condenser units would be necessary.