Page 12 - Climate Control News July 2019

World News
Europe’s
untapped
energy source
WASTE HEAT FROM towns and cities is a huge untapped energy source in Europe.
The Life4HeatRecovery project will look at ways to use it to heat homes and supply hot water.
The average mid-sized supermarket in Eu- rope produces enough waste heat from its refrigeration and air conditioning units in one year to be able to provide the thermal en- ergy needs of 200 homes over the same peri- od, according to Roberto Fedrizzi of EURAC Research, which coordinates the Life4He- atRecovery project.
“It’s not just our supermarkets producing this kind of waste – there are data centres, factories, hospitals, offices and many other buildings and institutions in towns and cit- ies all over Europe producing this energy as a by-product of their ac-
tivities, all too often
just wasted into the at-
mosphere,” he said.
Life4HeatRecovery
is an EU LIFE funded
project looking to use
wasted energy recov-
ered from different
sources and apply it to
district heating sys- Life4HeatRecovery tems. To do this effi- project.
ciently, the project is developing complete, pre-fabricated “skids” which collect the waste energy using heat pumps.
“The heat pumps are used in two ways. The low-temperature waste heat can be warmed to a level that is useful for district heating,” Fedrizzi said.
“This is done by connecting a heat pump to this waste source which increases the temperature of the available heat from around 10-30oC to 70-80oC. This is then connected to the district heating system and the heat is made available for tradition- al district heating networks. The other pos- sibility, however, is for a new generation of district heating networks. These directly distribute the waste heat through the net- work: this heats the water in the network to around 10-20oC and this low-temperature water is distributed to the door of the build- ings on the network.”
At the moment, the project is working at four demo sites. ✺
Roberto Fedrezzi is coordinating the
Transcritical solution for Italian supermarket
ITALIAN SUPERMARKET, GRUPPO MAXI DI HAS CHOSEN ARNEG TO DEVELOP ITS ENTIRE FOOD REFRIGERATION SYSTEM AND TO EQUIP ITS NEW STORE WITH ARNEG REFRIGERATED CABINETS.
MAXI DI’S GOAL was to create an environ- mentally-sustainable system, using a zero-im- pact gas. Arneg partnered with Carel to create a tailor-made solution that features modulating ejector technology.
The medium-sized store (2,300 square me- tres) has an Arneg Booster transcritical com- pressor rack that uses CO2, carbon dioxide, as the refrigerant.
Equipped with eight compressors, Carel elec- tronics and ejectors Arneg has supplied more than 50 refrigerated cabinets - 44 medium tem- perature and 13 low temperature.
All the cabinets are equipped with Carel’s MPX PRO, the compact and flexible controller that effectively combines ease-of-use, stable control and energy savings.
The CO2 compressor rack is controlled by the pRack pR300T, three Carel EmJ modulating ejectors, with a total capacity of 185 kW.
With the compressor rack operation in ejector mode the integrated solution can reduce the cabinet superheat set point down to 0.5°K.
In this way, the evaporators work in a semi- flooded mode with a higher pressure set point, optimising compressor rack operation
and reducing the energy consump-
tion of the entire system. This solution brings ener-
gy savings during the sum-
mer of up to of 25%, when
the outdoor temperature is
higher, but also in winter, via the heat recovery system that provides heating inside the building.
One essential feature of the ejector solu- tion is continuous modulation which allows the system to continuously adapt to the var- iations in operating conditions that are typi- cal of refrigeration systems.
The entire system is supervised by Arneg ser- vice through its IRIS Energy control centre, opti- mising performance and ensuring there is no wastage thanks to the Carel boss supervisor, which also provides predictive maintenance.
Arneg's refrigeration engineering director, Enri- co Zambotto, said Arneg has been working with Carel for many years.
“Technological innovation has allowed us over time to offer increasingly efficient and environ- mentally-friendly solutions, just like the one at the Famila supermarket,” he said.
“Now we are using ejectors in other installa- tions and always using natural refrigerants at numerous stores in Italy”.
ABOVE: The Arneg Booster transcritical compressor rack that uses CO2, carbon dioxide, as the refrigerant.
BELOW: Three Carel EmJ modulating ejectors are part of the solution.
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