Partnerships between energy service providers and cold chain operators can unlock significant savings and operational efficiencies. By analysing plant systems and optimising condensate return, cold storage facilities can minimise energy use, prevent system contamination, and ensure reliable steam and refrigeration operations. Proper design and ongoing maintenance of condensate systems are essential to support the delicate balance required in temperature-sensitive storage environments.
AES works closely with clients to optimise CR systems. Associated Energy Services (AES) Commercial director, Dennis Williams uses an AES food sector client as an example: “As our client has no fundamental technical understanding of the heat exchange systems within its facility, it cannot determine the percentage condensate return that can be achieved. Solo and third-party assisted tours of the plant provided technical guidance and isolated sections to determine condensate return flows, revealing potential condensate contamination. Several process units were identified to be addressed by the client. This is an ongoing process.”
Economics of condensate return
At another industrial manufacturing site, AES identified process issues in heating and cooling cycles that are resulting in high Total Dissolved Solids (TDS) and hardness in the CR returned, making it unusable at the boiler house: “We proposed a control system designed to allow for a post-cooling cycle flush. This will ensure that high TDS and hardness is flushed before steam is introduced, thereby ensuring clean CR. The expected savings are approximately R6 000/month for every 1% improvement in the CR to the hotwell. With a potential upper limit of 80%, significant savings can be achieved.
In short, the higher the temperature at which condensate is received, the better the energy saving. This justifies investment in the recovery process.
Williams recommends analysing where and how energy is used – and identifying the best-matched applications: “Where energy benefits are low, lower grade energy uses such as cleaning water (typically 60°C) should be substituted. By using the recovered low temperature CR, less water is needed – together with less steam – to heat the cleaning water.
‘Return’ to solutions
He observes that while some challenges are transitory, others can be severe and costly – such as introducing contaminated or high TDS CR into the boiler steam system: “If left unattended, this causes boiler fouling and plant failure. Contamination can lead to boiler control issues (fluctuating water level and boiler trips), and even carry-over of water slugs into the steam range – with potential for water hammer and line damage.”
The solution is proper design, layout and planning of condensate recovery systems: “Designs differ between plants: for example, a high-speed paper machine versus a heating coil on a cooker vessel. Regular maintenance of heat exchange equipment and testing of both CR and product for signs of leaks between the steam and product spaces is also critical.” Hence, AES prioritises preventing system deterioration and managing feedwater chemistry.
“Clear and timeous communication between AES and our clients is critical in managing expectations, and in achieving the best results. It is a partnership,” Williams concludes.
Source: Supplied by AES, edited by Eamonn Ryan