Adaptive Cooling Water Control for Sterilizers

Abstract: This thesis was conducted with the objective of reducing water consumption byoptimizing the cooling systems of steam sterilizers. As water is a precious resourcewith great environmental effects, it is important not to waste it. Consequently, thereis a need for a more resource-efficient cooling water system. The project focuses onthe development of a system that more efficiently regulates the cooling water utilization by optimizing temperatures. The goal of the project is to achieve a 20% reduction in water consumption of the GSS-91413 model steam sterilizer manufacturedby Getinge. In order to achieve the goal, changes were made to the cooling systemand control logic of the cooling system. By integrating a proportional valve at theoutlet of the cooling system, the system was pressurized with the coolant resultingin greater energy transfer between the condensate and the coolant. The developedcontrol logic incorporates process data combined with an equation-based approachthat utilizes temperature data to adjust the proportional valve leading to increasedcontrol of the flow of the coolant. As a result, the overall water consumption of thesystem was reduced by more than 50% while the maximal temperature of the systemdid not rise more than 1.5%.