Performance analysis for deep borehole heat exchanger heating system coupled plate heat exchanger based on TRNSYS

The active development and utilization of deep geothermal energy to compensate energy shortage of building heating is a promising access to improve the reform of energy supply side and environmental protection. In this paper, based on the dynamic coupling characteristics between the load side, heat pump unit and buried pipe side, the model covering the deep borehole heat exchanger (DBHE) heating system coupled plate heat exchanger was established by MATLAB and TRNSYS. And the influence law of multiple factors on system was conducted to explore the operation performance of system. The study showed that with the depth of DBHE extending, increase of the buried pipe depth, the circulating fluid temperature of system increased, the average heat extraction of heating season was gradually raised, the average energy consumption of system decreased. As the inlet fluid velocity of the buried pipe increases, the average Coefficient of Performance (COP) of system gradually decrease, i.e, the system energy consumption gradually increased. The results provide a theoretical basis for the further optimization of DBHE heating system, and have great significance for practical engineering construction.