Analysis of heat transfer performance and economy of different types of ground heat exchangers

Carries out the soil thermal response tests of heat extraction in winter and heat rejection in summer for DN25 single U-tube, DN25 double U-tube, DN32 single U-tube and DN32 double U-tube. Combined with the heat exchanger test result and initial cost, analyses the economy. The result shows that DN32 single U-tube is the best, DN25 single U-tube is the second and DN25 double U-tube is the worst.