Improving the heat transfer efficiency of a direct-flow recycling boiler using organic fluid

M.A Peretyatko,P.V Yakovlev,S.A Peretyatko,V.S Litvinenko

doi:10.1051/e3sconf/202126604009

M.A Peretyatko, P.V Yakovlev + Show 2 more

Open Access

https://doi.org/10.1051/e3sconf/202126604009

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Abstract

This paper considers the problem of studying the heat transfer exchange during boiling in a direct-flow recycling boiler using an organic coolant. The study was conducted using numerical modelling in the ANSYS software package. Asaresultofthestudyavisual picture eofvaporphasedistributionwasobtained. This picture shows that the studied heat-exchange surface can be conditionally divided into two areas: the area of intense vaporization and the area in which the degree of dry vapor varies insignificantly. Analysis of changes in the heat transfer coefficient along the length of the heat-exchange surface led to the conclusion that heat transfer in the second area is inefficient. Based on the results of the study, it was concluded that intensification of heat transfer is necessary, for which it is proposed to install a separator at the boundary between the selected areas. The subject of the study is the dependence of the variationin the heat transfer coefficient along the length of the pipe and the determination of the boundary between the selected areas at various values of the defining parameters. Numerical simulation for therange of variationofthe defining parameters corresponding to the actual temperature regimeof power steam boilers and the conditions for the implementation of heat recovery in organic Rankine cycle unitswas performed.

Highlights

The policy of introducing energy-saving technologies, implemented in recent years, determines the need tomaximize the use of waste heat ofvarious enterprises, power plants, and boiler houses [1]
Available low-temperature heat can be used to generate electrical poweratsmall power plants based on the principle of the organic Rankine cycle (ORC)
Thermal power plants operating on the Rankine cycle are quite common

Summary

Introduction

The policy of introducing energy-saving technologies, implemented in recent years, determines the need tomaximize the use of waste heat ofvarious enterprises, power plants, and boiler houses [1]. Available low-temperature heat can be used to generate electrical poweratsmall power plants based on the principle of the organic Rankine cycle (ORC). An increase in the heat transfer surface to ensure a margin of dryness value of steam leads to an increase in the cost and complexity of the design of the direct-flow boiler [5,6]. To solve this problem, it is necessary to study the heat transfer in the evaporator. The I study aims to determine the nature of the change in the heat transfer coefficient along the length of the pipe during the boiling process and to define the boiling pattern

Model description

Simulation results

Findings

4Discussion of the results