The methods of the theory of generalized conductivity [1, 2] are used to approximate the effective/equivalent thermal conductivity of defect-free single-walled carbon nanotubes (CNTs) with a scroll-roll structure in the longitudinal and transverse directions relative to the folding axis. Due to the lack of any experimental data and analytical estimates on the longitudinal and transverse thermal conductivity of nanotubes with a scroll-roll structure, the results of an approximate assessment were obtained for the first time, which can be considered predictive. Carbon nanotubes (CNTs) are of considerable interest in a wide variety of fields of science and technology, as they possess a whole range of extreme mechanical, electrical and thermophysical properties [3-4]. A single-layer defect-free carbon nanotube with a scroll-roll structure is shown in Fig. 1a. It is usually represented as a folded sheet of graphene.
$^1$\
$^2$\
$^3$All-Russian Research Institute of Metrology named after D.\, I.\, Mendeleev