ACR Journal

April | May 2020 REFRIGERATION 38 HTF with staying power Volume 6 No.3 Background Rea Valley Foods has been based in Shropshire since 1925 and specialises in the production of cooked meats for supply to the major UK retailers via delicatessen and prepack. Rea Valley Foods has worked with Midlands-based refrigeration and air conditioning specialist Greencold for many years. Greencold is a company that oversees the design, installation and maintenance of commercial and industrial refrigeration systems and their core business is within the food-manufacturing sector. The cooling system at Rea Valley Foods is an air-cooled, low charge ammonia glycol chiller manufactured by Mayekawa (Mycom) at its European base in Belgium. For large chill installations where the operating temperatures throughout the building are similar, Greencold prefers to specify secondary glycol-based cooling systems with a low charge ammonia primary refrigerant. The main benefits oered are described as the relatively low risk to factory occupants of an ammonia leak, the ease of adding extra cooling to the system (additional coolers to new rooms), and the low pressure of the glycol side which minimises the risk of leaks and the low complexity of the system in general makes it easy to maintain. A study by Greencold and Climalife demonstrated that Friogel Neo heat transfer fluid supplied by Climalife has not deteriorated over the eight years it has been in the system at Rea Valley Foods. System at a glance Type of chiller: Air-cooled low charge ammonia glycol chiller Chiller manufacturer: Mayekawa (Mycom) Total cooling capacity: 210 kW Glycol inlet temperature: -8°C Glycol outlet temperature: -12°C Refrigerant: R717 (120kg charge) Compressor: 8-cylinder reciprocating with inverter speed control Condenser: Air-cooled; fans inverter speed controlled Evaporator: Flooded shell and tube with Danfoss ICAD expansion valves PHE: Alfa Laval gasketed with titanium plates Hot side process: 25% NaCl -4°C inlet -8 °C outlet Glycol process pumps: Grundfos Brine pumps: PCM Sodium glycol tanks: Stainless steel T304 5mm thick 7200mm L x 1500mm W The Mayekawa ammonia chiller at Rea Valley Foods