Development and experimental validation of simulation of hydronic snow melting systems for bridges

Scope and method of study. The purpose of this study was to develop a computer simulation program for the hydronic snow melting system and apply it in the design practice. A transient, two-dimensional numerical model has been developed for modeling the temperature response of the hydronically-heated slab and the snow melting process occurring on its surface. Combining this model with other component models, system simulation of the hydronic bridge snow melting systems that utilize GSHP as heat source has been implemented under the component-based simulation environment of HVACSIM+. The predictions of individual component models and the system simulation have been validated against measured data from an experimental GSHP-based hydronic bridge snow melting system. Using the simulation approach, parametric studies on the effects of various design parameters and control strategies on the snow melting performance and required heating capacity have been conducted.; Findings and conclusions. Validation results show that the system simulation is able to predict the snow melting performance and energy consumption of the system with sufficient accuracy for the purposes of system design and performance analysis. Results of the parametric studies show that, for a typical hydronic bridge snow melting system designed with the current ASHRAE snow melting loads, preheating the bridge pavement 3--5 hours before the snowfall is necessary to achieve the desired snow melting performance. It is much more energy efficient than the continuous idling operation described in the ASHRAE handbook. Based on the simulation results, the snow melting loads associated with various idling times for 10 US locations have been updated and tabulated in two tables to facilitate the design of the hydronic snow melting systems.