Numerical Investigation of a New Ventilation-radiator

Received: 25 April 2019 Accepted: 9 July 2019 The current study focuses on the efficiency of heat emitters (radiators) in the premises. The purpose objective of this study is to investigate an optimal heat transfer between the ambient air and the walls of the radiator to make a birth to a new economic system of ventilationradiator. A reduced computational domain was numerically studied in (2D) by CFD simulations with FLUENT and (k-) standard model. Near-wall treatment, a standard Wallfunction is applied. Through this study, it was found by an analogy of ventilation-radiator system with a heat pump HP that cold air supply decreases the COP of HP, and therefore increases the energy consumption of heating system (combustible or electricity) and makes it costly and uneconomical. Wherever, elliptical tubes ensure a very high of heat exchange coefficient by convection in cross flow and staggered arrangement tubes. That results in an important COP of installation, with reduced costs, which making the system economical and exploitation costs reasonable. According to the findings of this research, a new economic system of ventilationradiator system is proposed, which is based on the increase of the heat transfer coefficient by convection (αcon), of the external surface of the radiator by placed elliptical tubes with a cross flow to the radiator, and a heat exchanger at an opening channel in the wall behind, that recover heat from the exhaust hot air discharged to outside, by the fresh air brought from outside. An extension of the external tube of the heat exchanger (used air) is proposed to ensure the correct flow of air brought from outside. The difference of quantity of energy with and without heat exchanger increases simultaneously with outside air temperature which passes through the heat exchanger where it undergoes a preheating by absorbing a quantity of heat from the discharged hot air to outside through the annular passage of the heat exchanger. This quantity of energy is the gain of installation (reduction of the energy consumption necessary for heating), and this heat flux recovered advantage our system over other heating systems. This directly affects the performance of the installation.