HEAT TRANSFER INSIDE THE ROUGH-WALLED TUBULAR CHANNELS OF POWER PLANT ELEMENTS
Journal Title: Shipbuilding & marine infrastructure - Year 2018, Vol 1, Issue
Abstract
Tubular channels with rough walls are now widely used for the formation of heat transfer surfaces of heat exchangers, which must meet the technical and economic requirements for power plants. Among these requirements, intensity and compactness are the main ones. The implementation of these requirements is possible with the intensification of heat transfer processes in a confined space. As shown by prior studies, the intensification of heat transfer on rough surfaces is based on a complex analysis of the effect of roughness in geometric parameters and thermophysical properties of heat agents on their efficiency. At the same time, the results of these studies are limited to the investigated heat agents, as well as the relative roughness heights. To compare the results of experimental studies on heat transfer, a generalized mathematical expression is derived on the basis of the Lion equation. It is intended for determining the heat transfer coefficient of rough surfaces taking into account the influence of velocity distribution on temperature drop in the turbulent core of the flow and the dependence of thickness of the viscous sublayer on the flow mode. The height is determined as the key factor of roughness. Surface roughness is divided into technical and regular. Comparison of the obtained solution to the available experimental data on heat transfer in technically rough pipes showed a difference in the results up to 10%, while in pipes with a regular roughness the divergence did not exceed 14%.
Authors and Affiliations
Valerii V. Kuznetsov
Keywords
Related Articles
- EP ID EP582265
- DOI -
- Views 58
- Downloads 0
EMERGENCY MODES OF MARINE TETHERED SYSTEMS
The article considers emergency operation modes of marine tethered systems (MTS) with a flexible connection (FC). The classification of accidents and emergency modes of the MTS with FC has been developed. It allows deter...
STUDY OF THE TOWING RESISTANCE OF PASSENGER CATAMARANS VIA CFD MODELING
The towing resistance of the projects AVP 07, AVP 07m, AVP 09 and AVP 11 has been studied in accordance with the needs of Artel LLC. The AVP 07m differs from the AVP 07 by the shape of the bottom at the aft end; thus, th...
THE MATHEMATICAL MODEL OF RESONANT FREQUENCY CONVERTER WITH PULSE REGULATION
On the basis of the state variables method, the mathematical model of the resonant converter is constructed, within which the analytical dependences are obtained, which allow calculating the durations of the inter-commut...
HEAT TRANSFER INSIDE THE ROUGH-WALLED TUBULAR CHANNELS OF POWER PLANT ELEMENTS
Tubular channels with rough walls are now widely used for the formation of heat transfer surfaces of heat exchangers, which must meet the technical and economic requirements for power plants. Among these requirements, in...
DETERMINATION OF ANALYTICAL DEPENDENCE OF PHOTOVOLTAIC CONVERTER MAXIMUM POWER POINT PARAMETERS TO PREDICT ITS YIELD BY DIRECT INTEGRATION
In the paper, the five-parameter model of the photovoltaic (PV) converter is analyzed. Based on the Lambert W function, an analytical dependence of the maximum power point of PV converter on the parameters of solar irrad...