Transient Ground and Grout Parameters Estimation Method for a Ground-Coupled Heat Pump System with Sandbox TRT Reference Data

Abstract

The ground and grout thermal parameters are very important for the Ground-Coupled Heat Pump system (GCHPs) design and simulation. An accurate ground and grout thermal parameter will result in a reasonable GCHPs design and operation control strategy. In this paper, a new transient ground and grout parameter estimation method was proposed. In addition to the ground thermal parameters, the transient borehole thermal resistance and the grout thermal parameters were firstly estimated by analytical models with the proposed method. Compared to the measured values by the thermal probes, the parameters estimated by the proposed method was reasonable and much more accurate than the conventional method. Accompany with the transient borehole thermal resistance estimated by the proposed method, the fluid temperature predicted by the ILS model was acceptable for both the early regime and late regime, and the maximum relative error for the fluid prediction result was up to 2.82%.