Second Brazilian supermarket invests in CO2 refrigeration

In December 2011 hypermarket Condor opened its 33rd store in Sao José dos Pinhais, in Curitiba, Brazil. The hypermarket uses climate friendly CO2 as a refrigerant in a subcritical system. In this first article about the installation we look at the key features of the equipment including the ECO2LÓGICO cascade system.

Bitzer and Eletrofio Refrigeracao Comercial developed the CO2 refrigeration technology used in the Condor hypermarket over a period of two years. The CO2 system reduces the energy consumption of the freezers by 20%, which translates into a 5% reduction in energy consumption for the entire refrigeration system.
 
ECO2LÓGICO CO2 cascade system
 
The CO2 refrigeration system installed by Eletrofrio is called ECO2LÓGICO and is a cascade system that uses CO2 as the refrigerant in the low-pressure (subcritical) stage, with direct expansion, and cools the freezers. Propylene glycol in used as the heat transfer fluid in a pumped system circulating in the CO2 cascade condensers. In the high-pressure stage a very low R134a charge is used.
 
The freezer system that uses CO2 was divided into 3 compact racks with 2 Octagon compressors installed in parallel. To save on space and facilitate installation and maintenance the CO2 racks were installed on the ceiling of the underground car park, underneath the Condor shop floor, positioned in close proximity to the freezer islands.
 
The high-pressure system consists of 6 semi-hermetic Bitzer compressors installed in a “rack house”.
 
Other system features include:

    * Heat recovery system capturing heat from the high pressure stage, producing hot water for the entire store;
    * Variable speed condenser fans, which guarantee greater condensing temperature stability. The condensing pressure varies with the ambient temperature, reducing energy consumption;
    * Carel electronic expansion valves used in the propylene glycol heat exchangers;
    * Carel rack controllers.

Advantages of the ECO2LÓGICO system

    * Uses low GWP refrigerant CO2 that does not damage the ozone layer
    * Lower Total Equivalent Warming Impact (TEWI) impact
    * Lower discharge temperature
    * Reduction in Energy consumption
    * Reduction in tubing diameter
    * Low cost of refrigerant CO2
    * Compact rack and installation thanks to smaller size of CO2 compressors and smaller number of compressors
    * Increase in useful life of CO2 compressors

Sustainable features of Condor hypermarket store
 
Architect Luiz Forte Netto designed the Condor store, and in addition to the CO2 refrigeration system incorporates the following eco-friendly features:

    * Glycol refrigeration system that reduces the MT HFC charge by 90%
    * Store design maximises natural light;
    * T5 fluorescent lighting that reduces energy consumption by 45% and lasts for 23 thousand hours;
    * Presence control lighting and daylight switching that turns lights on an off depending on sufficiency of natural light available;
    * Rainwater harvesting.

Background
 
Bitzer is a world leader in the manufacture of high quality and efficient refrigeration and air conditioning equipment. Since Bitzer Brazil inaugurated its CO2 Training and Technology Centre in its São Paulo factory, interest from OEMs in CO2 technology has been growing. For the Condor installation all the Eletrifrio engineers and installers, and Condor maintenance technicians received training at the Bitzer CO2 Training and Technology Centre.

 

 

The new subcritical CO2 commercial refrigeration system developed by Bitzer and Eletrofrio recently installed in the Condor hypermarket in Curitiba, points towards increasing investment in CO2 in Brazil. This second article about the CO2 system looks at the changes happening in the Brazilian commercial refrigeration market.

Modernisation of commercial refrigeration systems in Brazil could boost CO2 refrigeration market

 
A recently published “engenharia e arquitetura” article talks at length about the evolution of commercial refrigeration in Brazil. Across the country supermarkets are investing in new layouts, refrigerants, display cabinets and automation. The use of secondary refrigerants is becoming increasing common, having become standard in Carrefour and Wal-Mart, and making inroads in the Pão de Açúcar chain. As a result, systems, such as the Condor CO2 cascade system could become more common.
 
One of the driving forces behind changes to commercial refrigeration systems has been the need to invest in low ozone depletion potential (ODP) refrigerants. However, according to Eletrofrio Director Luiz Renato Oliveira Chueire incentives for investment in energy efficient and environmentally sound systems are lacking in Brazil. Those supermarkets that have chosen to invest in “green” technology such as CO2 refrigeration have done so as a result of their own initiative.
 
Training key to expansion of CO2 technology in Brazil
 
Within the “engenharia e arquitetura” article, CO2 receives several mentions. For example, Alessandro da Silva, from Bitzer Brazil emphasises the factors essential for supermarkets to enable them to capatilise on the benefits CO2 refrigeration systems:

    * The entire technical team, OEM, installer, and end-user, must be well-trained in the use of CO2 technology before installation;
    * It is important that in-depth studies are carried out before the refrigeration equipment is delivered to the client, so that the team responsible for commissioning the CO2 system know how it will behave, and so that the maintenance team know what to do;
    * The maintenance team should have in-depth knowledge of the interdependency of the high and low-pressure systems.

Mr Da Silva says, “Up until now all refrigeration systems using our CO2 compressors have performed significantly better than the synthetic refrigerants traditionally used in supermarket commercial refrigeration, such as R22 and R404A, in particular when looking at energy consumption”.
 
Mr Chueire on the other hand, says that new technologies such as CO2 refrigeration have their limitations. “The use of CO2 increases the initial investment and the system complexity, requiring highly trained technicians to operate them… For this reason we still have a lot of work to do to reach the ideal commercial refrigeration solution for Brasil.”
 
Background
 
In April 2010 the supermarket Verdemar, in Nova Lima, Mina Gerais, became the first supermarket in Latin America to use CO2 as a refrigerant. A second Verdemar store has since installed a CO2 plant, started-up in December 2011, and a distribution centre is set to follow soon. Supermarket Bon Netto in Jaguariúna in São Paulo is also investing in CO2, with a planned start-up of March 2012. Supermarket chains Carrefour, Supermaia, Wal Mart and Rede Extra are looking into the technology.

Fonte: R744.com