Chiller Control Using Dynamic Modeling for Free Cooling Mode Selection

The patent applies dynamics by transitioning from static temperature-based mode switching to dynamic modeling that continuously evaluates system state variables (water temperatures, flow rates, ambient conditions) to determine optimal operating modes. The controller dynamically adjusts condenser water flow rate and tower fan speed based on real-time model predictions, enabling the system to adapt to changing conditions and maximize efficiency.

The patent changes parameters by using multiple dynamic input variables (condenser water inlet temperature, chilled water temperatures, flow rates, ambient wet bulb temperature) instead of a single static temperature parameter. The model predicts performance across different operating parameters and selects modes based on comprehensive parameter evaluation rather than simple threshold comparisons.

The patent replaces complex mechanical control systems with a computational thermal model. Instead of using complex hardware-based control mechanisms, the system uses software-based thermal modeling to predict performance and determine optimal operating modes. This substitution of mechanical/control complexity with computational algorithms achieves optimization while managing overall system complexity.

The patent creates a virtual copy of the physical cooling system through thermal modeling. The model replicates the thermal behavior of the condenser, cooling tower, and heat exchanger, allowing the controller to simulate and evaluate different operating scenarios without physically implementing complex control hardware. This virtual copying enables sophisticated optimization with minimal additional physical complexity.

The patent applies dynamics by making tower water flow rate a dynamic variable rather than a constant. The model evaluates the relationship between tower fan power consumption and pump power consumption, dynamically adjusting the condenser water flow rate to optimize total energy consumption. This dynamic adjustment allows the system to find the optimal balance between fan and pump energy usage based on real-time conditions.

The patent changes the parameter of tower water flow rate from a fixed constant to a variable that is optimized by the thermal model. By allowing this parameter to change based on the balance between fan power and pump power requirements, the system achieves energy optimization while maintaining operational simplicity through automated model-based control.