Effects of Some Geometric Parameters in Energy-Efficient Heat Distribution of Pre-Insulated Double Pipes

Dorota Anna Krawczyk,Tomasz Janusz Teleszewski

doi:10.3390/proceedings2201520

Abstract

In the case of a computational example, a few aspects of the twin pipe geometry are presented, which have an effect on heat losses through double heating ducts. Proper positioning of the supply and return ducts in common thermal insulation can significantly improve the efficiency of the heating network and reduce heat losses. In this work, unit heat losses generated by the example double heating ducts and unit heat flux of the supply, return and exchange between the supply and return pipes as a function of the distance between the supply and return pipes were determined. On the basis of graphs of unit heat fluxes as a function of the distance between the duct and the return, one can formulate the optimal solution of the position, the supply and return duct in common insulation. In an optimal solution for the location of the supply and return ducts in a common insulation, both the total heat losses and the heat flux exchanged between the supply and return ducts should be minimal. All calculations were made in a proprietary calculation program written in Fortran language within the framework of the VIPSKILLS project. The work also presents solutions of temperature fields and heatlines in the cross-section of the duct of a dual heating network in the presented example.

Highlights

The basis for rational energy management is the selection and proper use of a heat source, and the distribution of heat
The location of double heating pipes in a common insulation slightly complicates the heat flow in double pipes compared to single pipes, in which analytical solutions can be used to determine heat losses
Determining heat flows in pre-insulated double ducts can be helpful in reducing heat losses and heating network optimization through appropriate location of a double duct in a common thermal insulation

Summary

Introduction

The basis for rational energy management is the selection and proper use of a heat source, and the distribution of heat. Twin pipes (double heating ducts) are becoming more popular, which are implemented with a common insulation. The location of double heating pipes in a common insulation slightly complicates the heat flow in double pipes compared to single pipes, in which analytical solutions can be used to determine heat losses. Bøhm and Kristjansson [2] compared heat losses in single, twin and triple (two supply pipes and one return pipe) buried heating pipes. Determining heat flows in pre-insulated double ducts can be helpful in reducing heat losses and heating network optimization through appropriate location of a double duct in a common thermal insulation. The purpose of this publication is the numerical analysis of heat exchange for different locations of double pipes in the thermal insulation layer. The calculations were made using the boundary element method, which was used in the calculation program as part of the VIPSKILLS project [3]

Calculation Example of a Twin Pipe

Conclusions