Technology Working Principle

Cutting-Edge Technology

PRS Technology is based on the physical principle of Thermal Accumulation provided by the heat of fusion of eutectics previously frozen by circulating refrigerant when power from mains and/or solar has competitive prices and/or is available.

principle 1

PRS Reefer Containers have Thermo Accumulators (TA) installed on internal walls and ceilings.

A Smart Thermo Charger (STC) is connected to the PRS Reefer Container and generates frozen gas that circulates into all Thermo Accumulators, which store cooling energy. This loading procedure takes between 48 and 72 hours.

Once the Pre-Trip Thermal Charge is complete, the STC and power supply are disconnected and the Thermo Accumulators release the stored cooling energy, which maintain the preservation conditions at the optimal values. This principle allows PRS Reefer Containers to be independent from a power supply for up to 25 days.


Thermal Autonomy – Transport Mode

Thermal Autonomy is complete when the PRS Reefer Container maintains an internal temperature of 0-5°C, which occurs after the Full Thermal Charge in accordance with ATP.  Those ATP conditions require constant a 30°C temperature (without sun radiation), and pre-refrigerated products having a heat of evolution less than 20 W/ton. This mode is used during transport, guaranteeing an unplugged and uninterrupted cold chain.


Constant Temperature into PRS Cold Stores

PRS Cold Stores fulfils with the fundamental requirements for optimal preservation of fresh foodstuff as defined by ASHRAE (American Society of Heating Refrigeration and Air-conditioning Engineers):

  • Temperature control in the overall cold store with +/- 0.2°C accuracy vs. the set point. It allows keeping the product temperature very close to the maximum freezing point (0°C). Figure hereafter shows a comparative temperature recording of a PRS Cold Store and a conventional cold store
  • Relative humidity higher than 90%, avoiding desiccation
  • Air velocity lower than 0,1 m/s, avoiding desiccation.
grafico 1
 

Comparative temperature recording of a PRS Cold Store vs. a conventional one.

  • Ripple in conventional cold store: ± 1,63°C
  • Ripple in PRS Cold Store: ± 0,24°C
  • Ripple of conventional cold store vs. PRS: +679%