Refrigeration using the Eutetic Plates system is ideal in the distribution of both frozen food, at negative temperatures from -18°C/ -25°C, as well as for fresh food at positive temperatures from 0°C/4°C. Highly cost effective, the Eutetic Plates system is superior to an air-blown system (Thermo King type).
The operating principle of the Eutectic Plates system is quite simple, and is similar to how the refrigerator in your home works: during the night, while the truck is parked and the refrigerating system is recharged, the eutectic liquid inside the eutectic plates is frozen at -40°C (for negative temperatures) by the circulation of the freon pumped by the motocompressor. Cold temperature is generated by the heat exchange between the surface of the eutectic plates and the inside enviroment.
For the whole duration of the delivery day (15 to 20 hours) the inside temperature will fluctuate between –25°C and –35°C depending on the number of side doors and how many times they are opened.
At the end of the working day when the truck returns to the warehouse, it is reconnected to a three-phase power line. This will allow the motocompressor to recirculate the freon and freeze the liquid inside the eutectic plates, preparing it for the next day.
THE EUTECTIC SYSTEM VERSUS A FORCED AIR SYSTEM
A comparative study between the eutectic refrigeration system and forced air system has been completed by a customer based in a tropical climate, using both systems for one working year.
* Costs including the daily maintenance expenses of the refrigerating unit.
The daily consumption of electric power of the eutectic plate refrigeration system is 8% lower than the forced air system (in red). The electric consumption is in fact a big issue in the operating costs. In the eutectic refrigeration system, the daily operative cost is limited to the electric consumption while in the forced air system, the daily operative costs also include fuel consumption and maintenance. The difference in the final cost is an additional $15,13USD (24,5%) per day.
This graph analyses the temperature loss inside the refrigerating unit:
The data is analysed in °C per Hour. According to the graph, the eutectic plate system maintains the temperature hourly 13,76% more. Better efficiency is obtained by the combination of high insulation value and a eutectic plates refrigeration system, resulting in the better preservation of your product. It is also cost effective, as not using this system results in an increase in annual operating costs of 24,5%, which includes regular maintenance.
ADVANTAGES & DISADVANTAGES
PARAMETER
MECHANICAL SYSTEM
EUTECTIC PLATE
Operating Scenario/route application
Excellent for long service runs (time on road)
Excellent for daily runs (up to 10-12 hours)
Insurance
Refrigeration failure means a crisis for product protection
Excellent for product protection
Initial Cost
High
Low
Life Cycle Cost
High
Low
Temperature Response
Excellent response to temperature increase
Slower response to temperature increase
Complexity
High
Simple
Down Time
Down time limited to precooling, loading and refueling
Exhaust discharge and high noise level, inoperable in certain high population areas
Few moving parts, quiet, no pollutants
Effective System Life
5 years with proper maintenance
Life of truck plus
SNAP COUPLING SYSTEM
For every cold technician it is the ideal for the refrigerating unit to be separated from the refrigerated body. The refrigerating unit should be based in the warehouse and not fixed to the vehicle, as this protects the component from being damaged by stones, mud, snow and salt on the road. More importantly, however, is in case of maintenance to the unit, repair could be done while the vehicle is on delivery, and it would not be necessary to take the vehicle out of service. The technical problem of this solution has always been the danger of leakage of refrigerating gas during the connection/disconnection operations of the fast coupling system. The synergy developed between the supplier and the technologically advanced components used in the production of fast coupling device has allowed us to limit the gas leakage within 25 grams a year.
Cold Car has always believed in the respectful preservation of the environment, organising the CO2 project in 1999. In a trail phase starting in 2001, prototypes were created for use in real working situations of different simulated climatic conditions. And from August 2003, a refrigerated body was successfully manufactured and used by a Unilever dealer as a distribution vehicle in a locale of rough climatic conditions. The CO2 project is only one example of the many projects and studies that are currently being done to improve efficiency and aide in the preservation of the environment.
ATERNATIVE REFRIGERATING SYSTEM -
ICE-CREAM DISTRIBUTION TRUCK USING CO2 AS REFRIGERATING GAS
Technical specifications:
Motocompressor in 2 stages using R744 (CO2) in both stages in order to obtain a temperature of -35° C
3 kw, 2 cylinders, semi-hermetic compressor with a gas cooler in two stages and energy recovery through a pressurized plate heat exchanger and a suction tube heat exchanger
4 evaporators at -33° C through eutectic plates
lab test conducted at 27,5° C (exterior temperature) shows a 35% more efficiency than a standard refrigerating system working on freon R507
overall performances are improved: the freezing time of the eutectic plates is reduced from 12 hours using R507 to 9 hours with R744 (CO2)
