Experimental Study on Thermal Insulation Effect of the Buried Oil-Gas Pipelines in Permafrost Regions

Figure 8

Temperature regime around the bare pipeline model at different freeze-thaw cycles: (a) , (b) , (c) , (d) , (e) , and (f) .

(a) 1 cycle

(b) 2 cycles

(c) 3 cycles

(d) 4 cycles

(e) 5 cycles

(f) 6 cycles