Eventos Anais de eventos
COBEM 2021
26th International Congress of Mechanical Engineering
Energy and exergy analysis for a VRF system for a residential building
Submission Author:
Ana Lívia Formiga Leite , PI
Co-Authors:
Ana Lívia Formiga Leite, Carlos Antonio Cabral Santos
Presenter: Ana Lívia Formiga Leite
doi://10.26678/ABCM.COBEM2021.COB2021-1810
Abstract
Nowadays, there is a global effort to reduce the greenhouse gas emissions. A large part of these emissions occurs in the energy sector. Within this sector, buildings are of great relevance. Energy efficiency can be the solution for minimizing emissions that negatively impact the environment and for minimizing natural resource consumption. VRF (Variable Refrigerant Flow) systems can perform at a high capacity with several indoor units interconnected with few outdoor units. This system has a better temperature control in each space, which allows greater efficiency for the installation. In other countries or even in other regions of Brazil, VRF is widely used in commercial buildings. However, in the northeast region of Brazil, even though it is a region with a predominance of hot and dry weather, the pursuit for the installation of more efficient air conditioning projects is still not a priority. In order to achieve a more sustainable future, buildings must pursue the goal of becoming a net zero energy, that is consume less energy as possible and generate the energy necessary for the building. In this context, air conditioning systems play a fundamental role, as they are responsible for a large part of energy consumption. In the city of Teresina, it is quite common for residences to have two to three air conditioning units. Because of this, in buildings with many apartments, the demand for electricity is quite high. Therefore, this work aims to the analyse an air conditioning system with variable refrigerant volume (VRF) for the installations of a residential building in Teresina, Piauí. An energetic, an exergetic analysis and an economic analysis are performed. The thermal load calculation was carried out, as well as the selection of equipment for the system through catalogues and software from manufacturers. The first law of thermodynamics was applied to determine the coefficient of performance. Exergetic analysis is applied to identify which component of the system most destroys exergy and, thus, make the relevant changes in that component to conserve more energy. Exergetic analysis is also the basis for carrying out more complex analyses such as exergoeconomic and exergoenvironmental. An economic analysis was carried out considering the initial cost installation and operation costs and the investment payback. In this work, it is expected to verify the economic feasibility for air conditioning by VRF in a residential building, as well as to evaluate the energy performance of the equipment.
Keywords
Energetic efficiency, Economic Feasibility, air conditioning
