The major task of food processing applications today is to ensure the freshness of perishable goods. Storages are used to smooth out highs and lows in production, allowing a more continuous supply to customers, and help maintain the quality of produce.
The warehouse of Courchesne Larose (Michal Inc.) is spread over an area of 100,000 ft2 with 40 ft. of height, able to accommodate 2 069 945 kg (4 563 442 lbs) of food per day. It includes 22 ripening rooms for bananas, a main dock with 19 garage doors, a banana dock with 3 garage doors. The temperature in the rooms varies between 0 and 15˚C.
Carnot Refrigeration Inc. has designed and manufactured a tailored system for this warehouse. Our refrigeration system with NH3/CO2 provides effective and reliable cooling, with an increase of the energy afficiency (4 times better than in the former warehouse). In addition, the use of CO2 and reducing the level of ammonia used increase the safety of the building for its workers and neighbors, while minimizing the negative impact of traditional refrigerants on the environment.
It should be noted that Carnot Refrigeration has incorporated new technologies such as the total recovery of the heat generated by the compressors and free cooling.
Although the technology is innovative, it is now proven, optimized and reliable.
Hot gas provides a quick and efficient evaporator defrost. Compared with electric defrost, this method has the advantage of zero additional energy expenditure or adding heat in the energy balance of the system. Hot gas defrost offers the possibility of heating the docks and all other areas of the warehouse as needed, always without additional energy expenditure and no additional mechanical equipment (pumps, loop glycol, heaters, etc.).
The NH3/CO2 refrigeration system is designed to recover direct heat from the discharge gases of the CO2 compressors to fuel recovery coils, to heat the ambient air of offices and the warehouse space that requires heat, such as the shipping dock and workshop. This option provides recovery capacity (available heat) up to 8 times greater than with the use of an intermediate loop glycol.
Using CO2 by direct expansion in cascade with ammonia, our system stays in FC mode (free cooling) when the outside temperature is below 8 °C. This mode is maintained for 4,000 hours in the Montreal area.
During these hours of FC mode, NH3 compressors remain completely stopped. These breaks increase the lifetime of the compressors, the lubrication system and other components of the ammonia loop.
In comparison, a recirculation loop with CO2 kept at -8°C outside temperature will remain below -15 °C to allow the TFC mode. It corresponds to a potential of 250 cars in the Montreal area. We expect that this system will reduce the total energy (kWh) requirement of the building compared to a direct NH3 system.