Numerical analysis and simulation of the heat recovery from wastewater using heat exchanger

Technical University of Cluj-Napoca, Department of Environmental Engineering and Sustainable Development Entrepreneurship, 103-105 Muncii Avenue, 400641, Cluj-Napoca, Romania

^* Corresponding author: timea.gabor@imadd.utcluj.ro

Abstract

The problem of global warming and the reduction of energy consumption have led to an evolutionary progress of research directed towards finding as many solutions as possible to these environmental issues. Firstly, this paper presents the background information on the role of wastewater as a source of heat for the future. Next, the paper includes the analysis elements that define a system for recovering thermal energy from wastewater. The main objective was to identify the parameters that determine the heat transfer. It has started from a conceptual model of the technological system that involves inputs and outputs characterized by technological, physical-chemical, measurable or imposed properties. In the second part this paper presents a numerical model elaborated for the analysis and simulation of the main physical processes, the mass and heat transfer, which underlie the operation of the heat pipe heat exchangers (HPHE). The numerical simulation of heat and mass transfer in the HPHE is computed by using Delphi 7 solver program. This program contained a series of sub-programs for the meshing of the field occupied by the HPHE, another subprogram for solving the meshing equations and the third for post processing. The design of HPHE is the key to provide a heat exchanger system to work proficient as expected. Finally, the result is used to optimize and improving heat recovery systems of the increasing demand for energy efficiency in residential buildings or industry.