Simplified method for forecasting outlet water temperature based on line heat source theory

The outlet water temperature of groundsource heat pump system has great significance for determining the pump efficiency and the status of the ground heat exchanger. Based on the technical code for groundsource heat pump system and line heat source theory, proposes a simplified method to predict the hourly outlet water temperature of buried pipe. Establishes a heat tranfer model of the groundsource heat pump system by simulation software, and obtains the hourly variation of outlet water temperature. The result shows that the simulation method can accurately predict the change of outlet water temperature. Analyses the influence of the operation period, load and daily operation time on accuracy of the outlet water temperature prediction by simplified method, and the result shows that the simplified method can be used to calculate the length of buried pipe.