Accelerate R744 units for warm climate applications!

Being part of ATMOsphere Asia 2016 in Tokyo was a very inspiring experience. Among the latest achievements presented by leading Japanese manufacturers was the effective development and market introduction of small-size R744 commercial refrigeration units. Pilot systems shipped to other South Asian countries will demonstrate that these units are viable alternatives, even close to the equator.

The audience discovered that R744 refrigeration technology is a success story not limited to Japan. As was the case for large European commercial refrigeration systems 10 years ago, scepticism used to dominate the area. Nowadays R744 is the preferred option for far-sighted end users, a trend that can be seen in Asia. Hundreds of small Japanese convenience stores are now equipped with R744 technology. Various field measurements performed by different players showed that the energy savings compared to previous HFC installations reach up to 45%!

This is good news for southern Europe. The phase-in of natural refrigerants into the supermarket sector in the warmer regions of Europe can accelerate! End users are fed up with the successive churning out of synthetic refrigerants by the chemical industry in the last few decades.

Natural refrigerants solve this problem – now let’s make an effort to further increase the energy efficiency of the solutions they are looking for, like integrated refrigeration packs. In new and completely remodelled supermarkets, the latest R744 refrigeration rack solutions will take care of all the energy flows from the store or building in an efficient way. Besides cooling the store equipment, the entire energy supply to the HVAC and hot water systems will be managed in a cost-efficient manner – reducing the total cost of ownership for end users. Several pilot supermarkets are performing excellently across Europe, equipped with parallel compression booster systems enhanced with the latest ejector technology.

As reported by several experts, the work recovery efficiency of R744 ejectors is generally in the range of 20-30% at elevated ambient temperatures. Ejectors also simultaneously pump additional liquid through the evaporators, improving system performance significantly. This increases the suction pressure of the compressor twice, due to the elevated evaporation temperature (flooded evaporation) and the pre-compression of the evaporator outlet fluid.

Component manufacturers will soon be ready to deliver serial production parts to the market: this is a major step forward for the large-scale introduction of centralised commercial refrigeration systems in southern Europe. This ejector technology can be applied in other applications too, such as industrial or commercial cold storage refrigeration systems, transport refrigeration systems, industrial heat pump applications, or chillers.

However, training to support local vendors and installers is critically important. To support this vital need, the EU has provided funding for a H2020 project called SuperSmart, which aims to improve the energy efficiency of supermarkets by improving staff expertise and facilitating knowledge transfer.

SuperSmart tackles barriers both short-term (awareness and knowledge) and long-term (organisational, political and social), even though the impact on the supermarket sector may not be immediate. The purpose of the SuperSmart hub is to establish a knowledge transfer and promotional platform devoted to the supermarket sector in order to educate, train and bring together stakeholders from various backgrounds in such a way that facilitates the uptake of energy-efficient heating and cooling solutions. We look forward to welcoming you to the SuperSmart hub.

Armin Hafner / NTNU