Chiller Control Review

PE Tech was hired to conduct an engineering analysis to assess control issues with a newly installed absorption water chiller. The water chiller was installed in 2019 and the system had issues maintaining auto control of the water temperature due to the steam temperature control valve regularly operating out of control. To avoid the system shutting down, staff were required to switch the system over to manual operation, monitor the control valve, and adjust water temperature to the correct set point. The PE Tech team analyzed trended data and investigated differences in the design of the new system against the previous system to determine the root cause of the system control issues. The result of the study provided multiple recommendations to address instability in the steam control through system design adjustments and control logic strategies. These recommendations addressed the operating issues as well as supported safe operations by removing operator burdens and bringing the water temperature back within normal chiller operating specification limits.