ACR Journal

December 2021 | January 2022 REFRIGERATION 28 David Cooper, design manager at refrigeration contractor SURE Solutions, describes the satisfaction of being able to provide the answers to complex questions. Rising to the challenge Volume 8 No.1 As a system designer, it is always rewarding to be involved with challenging projects. Refrigeration is often one of the last things to be considered when a new factory plan is presented. It starts with a definition of what the site is aiming to achieve and what success looks like to set the scene, no matter the scale. Then there is a list of criteria, wants, needs, expectations and so on. This quickly sets the boundaries to work within. One of our recent projects, currently in the construction phase, was at a poultry processing facility for Cranswick. It presented plenty of challenges and, on reflection, ended up being a dream job from a design perspective. The operational temperatures ranged between -43°C and +125°C and the system had a heating/cooling capacity in excess of 3MW with dynamic operational temperatures. The factory was designed to process for 20 to 24 hours per day all year round, resulting in long production shift patterns requiring zero downtime, especially on various freezing processes. Close control process temperatures required consistent water at +1°C, while delicate production machinery susceptible to low velocity cold air meant managing warm humid air; ensuring condensation was not present in chilled areas. Additionally, no site services were permitted using synthetic refrigerant. Over time the cooling and heating loads were determined and subsequently there was a requirement to have dual temperature operation in several areas. Depending on the production pattern, demand for any one of these areas could change. The system had to adapt and do so efficiently. This had to be worked back into the plantroom to ensure the system was designed to accommodate a change in operational condition. The temperature swing was from evaporating temperature of -40°C to -10°C. When doing this on smaller loads it is most often achieved by regulating the evaporating pressure, although this would mean running higher temperatures inefficiently at a lower compressor suction set point. David Cooper Crane lifting a condenser to open plant area