Optimizing Performance of Pressure-Independent Control Valve for Hydronic Systems in Buildings

This study proposes the shape of a pressure-independent control valve (PICV) that minimizes the pressure drop to improve the flow performance of PICVs through target value modeling in accordance with the opening rate of the PICV. The model was verified by comparing the experimental values of the PICV at different opening rates with the flow rate and pressure drop based on computational fluid dynamics (CFD) modeling, and CFD simulations were performed based on the PICV opening rate and the improved model shape. The comparison between the PICV experimental values and the CFD modeling values indicated a flow rate difference of less than 4.65%, thus proving that the model satisfies the target flow rate. Based on this result, the PICV model was improved so that the minimum absolute pressure was increased and the pressure drop was decreased compared to the existing valve shape. Consequently, the energy requirements of the heating, ventilation, and air conditioning pumps of the building can be reduced, as there is no requirement for pressure drops, allowing the valve to operate without increasing the saturated vapor pressure.