Supercritical fluids are widely used in engineering technology, and the flow and heat transfer characteristics are very important for engineering design. However, due to the fact that the physical micro- and macroscopic behaviors of supercritical fluids are still open, neither the heat transfer mechanism nor the flow mechanism of supercritical fluids has been well revealed. It is widely believed that liquid-like (LL) and gas-like (GL) supercritical fluid are two phases distinguishable on a molecular scale. Only recently, has it become clear that the macroscopic transition from LL to GL supercritical state, when crossing the Widomline, is successfully detected in experiment, and explained based on the pseudo-boiling concept. In this paper, the abnormal flow and heat transfer behavior of supercritical CO
2are studied based on the pseudo-boiling theory. On the assumption that the transition from LL to GL is heterogeneous, an analysis method for pseudo-boiling heat transfer is developed from classical dimensional analysis and subcritical subcooled boiling theory of models. To analyze the pseudo-boiling resulting in heat transfer deterioration process of supercritical fluid, two dimensionless numbers which are
π= (
q
w·
ρ
l)/(
G·Δ
i·
ρ
g) and
π
13= (
q
w·
β
pc·
d
i)/
λ
gare proposed to explain the anomalous heat transfer characteristics in vertical upward heating flow. The former
πreflects the rate of conversion between gas-like and liquid-like fluid. The larger gas-like conversion rate promotes the rapid production of more high-temperature fluid in the near-wall region, and the latter
π
13characterizes the temperature gradient of gas-like film near the wall: the larger temperature gradient causes the gas film to cover the wall surface. The heat transfer deterioration may occur when the cooler liquid-like fluid of the core region cannot rewet the hot wall adequately. The new dimensionless numbers can successfully explain the heat transfer deterioration of supercritical fluid flow induced by pseudo-boiling. Our work paves the way to understanding the heat transfer and flow for supercritical fluids which establishes a relation among the internal flow, heat transfer field characteristics, boundary conditions and physical properties based on the pseudo-boiling theory preliminarily. The results of dimensional analysis can be applied to the similarity theory analysis of different fluids, which is of significance for promoting the theoretical research of supercritical fluid heat transfer on the basis of pseudo-boiling concept.