Project: Mansfield’s Fruit Farms, Chartham, Canterbury.

Planning implementation:
International Controlled Atmosphere (ICA) Storage & SRS Frigadon.

Refrigerant:
Primary R1270 hydrocarbon; secondary Hycool 20.

System start-up:
August 2008.

Introduction:
SRS Frigadon was invited by the client to present an alternative solution to the use of NH3 which was initially proposed for this unique installation. This opportunity was given to SRS Frigadon based on the reputation and success of previous SRS Frigadon equipment installations within the fruit growing industry.

Demands:
In view of the long term Controlled Atmosphere storage of fruit the client’s criteria being that product quality was to be maintained and that the system engineering was to ensure the client’s green credentials. Equally important was the system efficiency and to be compliant with all refrigerant regulations, health & safety issues.

Solution:
The simple solution proposed was to use low pressure heat transfer fluids which would be circulating throughout all of the 36 controlled atmosphere chill storage rooms. This together with the combination of the 5 x SRS Frigadon chillers using R1270 as the primary refrigerant together with the Hycool potassium formate food safe and biodegradable heat transfer fluids with zero GWP gave the opportunity for the client to have the most latest up to date environmentally friendly installation with virtually zero climatic impact. These rooms operating at -0.5°C / +1.5°C air temperature are simply defrosted by means of OCD (Off Cycle Defrost).

Technical specification:
Type of facility: Secondary Refrigerant System
Refrigerant: Primary: Hydrocarbon R1270 Secondary: Hycool®
Refrigerant volume: R1270: 90kg Hycool® 30,000ltrs
No of compressors: Twenty
Refrigerant temp: Primary: -9°C; Hycool® flow -3/0°C
Refrigerating capacity: 1150kW
Main components: SRS Frigadon air cooled MT chillers Grundfos internal / external pump arrangement. AIA Controlled Atmosphere 8.2m long coils Georg Fischer Cool-fit and PE electro-fusion pipe work. Hycool® potassium formate heat transfer fluids.

Special features:

  • Even fluid temperatures across the coils, no ice, no defrost.
  • Narrow TD of 2.5°C across the coils.
  • Minimal quantity of primary refrigerant.
  • Enhanced COP (Co-efficient of Performance) R1270 SRS Frigadon chillers.
  • Minimal product dehydration, no shrinkage.
  • Apples can be maintained in a perfect condition for 6 months plus.
  • Reduced service & maintenance costs.
  • Easy installation with packaged SRS Frigadon air cooled chillers.
  • Lower than predicted energy consumption.
  • Removal of risks associated with brazing on site
  • Comparison: Copper v ABS & PE plastic pipe line services: CO2: Copper: = 370W/m²K. CO2: Plastic: = 0.2W/m²K.
  • Minimal CO2 emission installation.
  • The client can achieve a high score of BREEAM points: This is a method by which environmental assessment & performance for which companies can achieve a high score of BREEAM points and is designed to stimulate energy efficiency.