Optimisation of condensing units according to EU's Ecodesign regulation (ECOCDU)
The objective is to provide increased obtainability for condensing units with low greenhouse effect. Based on the Advansor CDU with CO2 and Danfoss controls, the aim of the project is to increase seasonal efficiency performance ratio, SEPR, by 15%. In Denmark, the potential savings accumulated over 10 years is 186 GWh at a 10% market share for Advansor.
Project description
The objective is to provide increased obtainability for condensing units with low greenhouse effect. The Advansor product line of condensing units (CDUs) with CO2 together with Danfoss controls form the basis of this segment. From the line of products, two units are chosen for frozen and fresh products preservation, respectively. These are investigated with regard to the seasonal efficiency performance ratio, SEPR, as stated by the Ecodesign regulation in force from July 2016. The aim is to improve the SEPR by 15% compared to the current value. This figure relates to an annual sale in Denmark of approx. 8600 units and a potential market share of 10%. At a mean cooling capacity of 7 kW, this is equivalent to potential savings accumulated over 10 years at 186 GWh in Denmark. It is expected that the outcome of the project also will increase the potential market for the product line within the EU and, thus, generate additional saving on this market. The optimisation is performed by use of a mathematical model for analysing the components and the efficiency of the units. The improvements in efficiency are documented by measurements in a climate chamber.
Results
The project's main results are based on two products that show an improvement of theseasonal efficiency performance ratio (SEPR) measured according to the Ecodesign criterias:
• MT9: An improvement of the SEPR from 2.65 to 3.50 corresponding to 32 %.
• LT4: An improvement of the SEPR from 1.28 to 1.52 corresponding to 19 %.
These improvements, which are based on the use of a new product line of rotary compressors
with variable speed drive and an optimized gas cooler, can be used directly across the
entire product line. Therefore, they provide a much higher efficiency improvement than
the 15 %, which was the aim of the project. This makes it possible to increase the efficiency
of this product line with CO2 as refrigerant to a level corresponding to the best of the
competing products that use HFC refrigerants.
The secondary result of the project is method development:
• A rule of thumb has been developed to determine the permissible pressure drop in
the gas cooler as a function of the outlet temperature.
• Dimensioning of gas coolers based on the Ecodesign criteria.
By comparing different gas coolers and optimizing their geometry, something that has a
significant impact on price and performance, it becomes significantly easier to determine
the selection criteria. The analyzes show that in the particular case it would be possible
with simple changes to the original gas cooler to achieve a total efficiency improvement of
SEPR of 9 % with no additional cost.
Furthermore, the project has also looked at the possibility of using ejectors as a means of
increasing the efficiency of compressor aggregates with CO2. The tests performed with a
Danfoss ejector provide good efficiency improvements between 5 and 25 %. But experience
also demonstrates that in practice it is not easy to use ejectors in this segment, and
therefore there is a need for further research in the field.
Key figures
Period:
2016 - 2018
Funding year:
2016
Own financial contribution:
1.54 mio. DKK
Grant:
1.05 mio. DKK
Funding rate:
41 %
Project budget:
2.59 mio. DKK
Category
Programme
ELFORSK
Technology
Energy efficiency
Project type
Forskning
Case no.
ELFORSK 348-051
Participants
Teknologisk Institut (Main Responsible)
Partners and economy
| Partner | Subsidy | Auto financing |
|---|---|---|
| ADVANSOR A/S | ||
| Danfoss A/S |
