An unusual solution to a cooling problem

A US refinery found one of their diesel products was not being adequately cooled, and their initial assumption was that the last heat exchanger was fouled. They wanted to avoid shutting down the entire plant to swap out the exchanger and they didn’t want to reduce the amount of diesel going through the exchanger, as that would affect their production schedules.

They reasoned that extra cooling power would help and asked us to bring in a 400-tonne closed-loop chiller. However, even that couldn’t solve the problem.

When the 400-tonne chiller didn't work, we asked if we could bring in our experts to assess the situation. After reviewing the data, we recommended an unconventional arrangement: passing the water discharge back to the cooling water tower.

It was unconventional because, in 95% of cases, a closed-loop chiller is the most efficient way to go. But in this case, our calculations showed a different option was needed. Our recommendation was accepted and the system was configured for once-through cooling (OTC). It worked, and diesel temperatures dropped to safe levels.

A rapid response and a creative approach from our engineers and design team saved our customer continued frustration with a problem that was proving difficult to solve. As a result, our customer avoided the costs of extra cooling units and having to shut down the plant to replace the entire exchanger. Instead, the refinery was quickly back to full productivity.