Thermal response test and analysis of U-type vertical pipe of ground-source heat pumps

Taking a project in Shanghai as an example, conducts thermal response tests of the single U-type pipe with diameter of DN32 and the double U-type pipe with diameter of DN25 by means of a constant thermal flow method through the test device developed independently. Gains the heat exchange capacity of unit pipe length and the thermo-physical properties of soil. The results show that the heat exchange capacity of unit pipe length of the double U pipe is 20 percent greater than that of the single U pipe and that the heat conductivity of double U pipe is 15 percent greater than that of the single U pipe. Suggests considering geological conditions at site, heat exchange capacity of unit pipe length, pipe material, drilling condition, etc. when selecting the type of the buried pipes.