Abstract
When a pipe is cut off to repair fuel oil pipelines, the oil has to be drained from the pipelines. If the oil inside the pipe is frozen at both sides of a cutting plane, it is not necessary to drain the oil from the pipelines. In the present paper, such a freezing method is studied analytically and experimentally to establish a suitable construction method, where liquid-nitrogen (LN2) is used as a coolant and fuel oil-C is used as a typical example. From the result, thermal conductivity and thermal diffusivity of the fuel oil-C in a low temperature range were measured as a function of temperature in addition to the pour point and glass transition point. Furthermore, in order to compare the agreement between analysis and experiment, an analytical method was performed under various conditions. Finally, temperatures in analytical values were agreed well with experimental ones, and suitable position and time for cutting are clarified.
