EECA has published good practice guide to help operators improve the energy efficiency of medium- to large-scale industrial refrigeration systems, including cold stores and process chillers. The guide says equipment improvements can reduce energy use by up to 40%, while operational changes can deliver reductions of up to 20%.
The document recommends a whole-system approach covering design, installation, operation, maintenance and periodic review. It organises improvement work around three options: reducing refrigeration demand, improving an existing system and designing a new system.
Technical measures include minimising heat gains, optimising evaporator defrost schedules, reducing condensing temperature and discharge pressure, raising evaporating temperature and suction pressure, and using variable-speed drives on fans, pumps and compressors. According to the guide, reducing temperature lift by 1°C can improve the coefficient of performance by about 2–3%.
The guide also addresses compressor sequencing at part load, refrigerant piping pressure drops, insulation, refrigerant leaks, heat recovery, demand response and load shifting. It advises operators to undertake a life-cycle cost assessment for refrigeration plants more than 10 years old when determining the optimum time for replacement.
