Numerical analysis of heat losses by main heat pipelines under conditions of complete or partial flooding

MATEC Web of Conferences

2014

Abstract.Results of numerical simulation of heat and mass transfer in a wet fibroporous material in conditions of evaporation and steam diffusion were obtained. Values of heat and mass fluxes were established. The contribution of evaporation effect to total heat flux and need to consider volume fractions of water and steam into the structure of fibroporous material in calculation of effective thermal conductivity were shown. Nonstationarity of heat and mass transfer in conditions of considered problem can be ignored.

Section: Results Of Numerical Simulationsupporting

confidence: 75%

“…The largest contribution to the change of thermal conditions makes a change of thermal conductivity of thermal barrier material in wetting conditions [1][2][3]. One more important factor is a moisture evaporation [4,5] and a mass transfer [6].…”

Section: Introductionmentioning

confidence: 99%

Heat loss of heat pipelines in insulation moisture conditions with the evaporation

MATEC Web of Conferences

2014

“…1) are listed in Table 2 and in Fig. 2. 01029-p. 3 Validity and reliability of the obtained results follow from tests of the methods for convergence and stability of solutions on multiple meshes, fulfillment of the energy balance conditions at boundaries of the calculation domain, and is also confirmed by comparison of the obtained results and the known experimental [2] and theoretical [1,5,6] data obtained by other authors. The relative calculation error in all versions of the numerical analysis did not exceed 0.5%, which is acceptable for investigations of thermal conditions of the system under consideration (Fig.…”

Section: Results Of Numerical Simulationsupporting

confidence: 75%

Heat loss of heat pipelines in moisture conditions of thermal insulation

2014

EPJ Web of Conferences

“…The system of equations ( 1)-( 10) was solved by the finite-difference method [8] using an iterational implicit difference scheme. The characteristic features of the problem solution were the discontinuity of the thermophysical characteristics at the metal tube wall-wet fibroporous material interfaces and the presence of nonlinearity in boundary condition (5).…”

Section: Methods Of Solution and Initial Datamentioning

confidence: 99%

“…The largest contribution to change of thermal conditions makes a change of thermal conductivity of thermal barrier material in wetting conditions [1][2][3]. One more important factor is a moisture evaporation [4,5] and a mass transfer [6].…”

Section: Introductionmentioning

confidence: 99%

Heat and Mass Transfer in Wet Fibroporous Material Considering Moisture Evaporation

2015

AMR

Results of numerical simulation of heat and mass transfer in a wet fibroporous material in conditions of evaporation and steam diffusion were completed. Values of heat and mass fluxes were established. The contribution of evaporation effect to total heat flux and need to consider volume fractions of water and steam into the structure of fibroporous material in calculation of effective thermal conductivity were shown. Nonstationarity of heat and mass transfer in conditions of considered problem can be ignored.