Features of Calculating the Characteristics of Energy Complexes Using Low-Grade Energy

Abstract

The development of stationary energy seems to be an important aspect of introduction of energy-saving technologies in transportation sector. In Russia, it is conditioned by the main provisions of the Energy Strategy of the Russian Federation until 2030. In this regard, the problem of efficient use of low-grade heat based on the organic Rankine cycle (ORC) in stationary heat energy supply units in the transport industry is urgent. In particular, this task is typical for boiler houses converted from heavy fuel oil to gas fuel. In this case, the efficiency of ORC application will primarily be determined by the efficiency of the used heat exchangers (HE) with a phase transition, as a result of which, both technically and theoretically, the problem of designing and calculating the optimal characteristics of these HE will be of great interest.The article presents a theoretical and computational model of heat transfer during phase transitions in turbulent flows based on the relations obtained by the stochastic theory of hydrodynamics and heat transfer. The modelling of the effect of turbulence during the phase transition with undeveloped boiling of the bubble mode is considered. The comparison results show satisfactory conformity of the values obtained according to the formula based on stochastic equations with the values calculated according to the empirical formula for the flow in a pipe, used in the engineering method of designing heat exchangers. The results obtained open the prospect for studying the processes of heat transfer during phase transitions in turbulent flows of HE to reduce their overall and mass characteristics, as well as to increase the energy efficiency of both the devices themselves and the efficiency of the entire energy complex.