ICR Conference 2011: Development of natural refrigerant plug-in refrigerated display cabinets

By Sabine Lobnig, Sep 09, 2011, 12:24 2 minute reading

At the International Congress of Refrigeration (ICR) held at the end of August, research investigating the optimum natural refrigerant for plug-in display cabinets was presented by Carrier Commercial Refrigeration. The study, presented during the technical session “Environmental footprint from refrigeration II”, looked at both CO2 and R290 (propane), with R290 eventually selected as the preferred option.

For commercial refrigeration a range of plug-in display cabinets are currently available on the market. Most commercial plug-in cabinets exist in the capacity range of 600 W to 2.5 kW and are between the small domestic applications and the big remote systems. At the lower capacity range there are small Glass Door Bottle Coolers, which are similar to domestic refrigerators; for these R600a (isobutane) is the standard. At the upper capacity range there are open Multidecks of up to 2.5m length, which overlap with typical remote display cabinets. 

Carrier has been offering a range of hydrocarbon plug-in display cabinets for several years now, and thousands have been sold without any issues. 
 
Natural refrigerants for plug-in refrigerated display cabinets, Krieger T., Schrey R., Schuster M, Nugroho S., Carrier Commercial Refrigeration

The study, presented by Thomas Krieger, compared the thermodynamic properties of the alternative refrigerants CO2 and hydrocarbons, and simulated system efficiency. Relevant regulations were analyzed, and furthermore, the availability and cost level of required components was evaluated. 

As a result of the analysis, R290 (propane) was selected as the preferred solution for a Carrier product range. Propane, as a natural refrigerant, is a very good replacement for current HFC blends in commercial refrigerated plug-in display cabinets. R290 has no ozone depleting potential (ODP), a very low global warming potential (GWP), and a high thermodynamic performance enabling reductions in energy consumption.

R290 flammability controlled
 
As a first step in the range development R290 technology was designed and components were qualified. Due to R290 flammability, challenges such as electrical safety and a significant reduction in refrigerant charge - to a maximum of 150g, according to standard EN 60335, had to be met. As a second step, a cabinet type was transferred to R290 and launched as a pilot series. After more than 10 Million hours of field operation without any issues R290 was rolled out for a wide range of Carrier refrigerated display cabinets.

Due to constraints in the maximum allowable charge of hydrocarbons, the capacity range is limited, but with a properly designed system a wide range of typical plug-in applications can be covered. Furthermore, Carrier points out that the current legislated 150g limit might change in the future.

A 100% natural solution for supermarkets refrigeration

Carrier's experience with the first R290 cabinets over the past two years demonstrates that the risks associated with flammable refrigerants can be controlled with a safe product design, the right manufacturing measures, and the right shipping and field service measures.

Carrier has proven that a 100% natural solution for supermarket refrigeration equipment can be offered, with hydrocarbons used in the plug-in cabinets and CO2 used in the central remote refrigeration system.
 

MORE INFORMATION

By Sabine Lobnig

Sep 09, 2011, 12:24




Related stories

Sign up to our Newsletter

Fill in the details below