Trento (TN), Italy- August 2019
The EU H2020 project MultiPACK has given the opportunity of installing three state-of-the art CO2 systems for supermarkets in South Europe, able to supply all the required thermal energy needs of the site, i.e. refrigeration, heating, cooling and hot water production. The MultiPACK units include parallel compression, ejectors for expansion work recovery and liquid recirculation and evaporator overfeeding, together with full monitoring of operation and performances.
The selected installations are typical Italian neighbourhood supermarkets; they are located in Rome and in the Trentino region, North Italy, thus representing different climatic areas. The Trento location has 3001 Heating Degree Days; temperature and humidity values adopted in this manuscript were taken from an official meteo station, close to the supermarket (http://storico.meteotrentino.it).
The total shopping area of the Trento unit is 1750 m2, in a single-floor, isolated industrial-type construction, dedicated to commercial purposes.The installation of the MultiPACK units is part of refurbishment plans, which includes the entire HVAC&R system, display cabinets and cold rooms. According to the MultiPACK design, the unit is providing full thermal energy services to the site, i.e. Refrigeration, Heating and Cooling, while adopting the state-of-the art technologies for CO2 units in warm climates, which include parallel compression, two-phase ejectors and optimal evaporator use by superheat minimisation. The unit is fully instrumented, to monitor operations and energy performance in the field.
The unit installed in the Trentino region is presented in Figure 2. The shop ceiling indoor units are distributed in the shopping area; they provide heating and cooling by direct flow of CO2 inside the ventilated coils. In addition, the building also has centralized Air Handling Unit (AHU)that is activated only for summer dehumidification. This specific layout, with indoor ceiling units, can provide a practical option in those refurbished sites with limited ceiling height.
The table below reports the design capacities of the system, together with the total areas of the site.
|QMT,D||90 kW @ -4°C|
|QLT,D||22 kW @ -30°C|
|QH,D||200 kW @ 10°C external temp.|
|QAC,D||280 kW @ 30°C external temp.|
|Shopping area||1750 m2|
|Total area||2200 m2|