Eventos Anais de eventos
ENCIT 2016
16th Brazilian Congress of Thermal Sciences and Engineering
Technical and Economic Feasibility of a Cogeneration System Applied to Hotels in Brazil
Submission Author:
Antonio Luiz Zambelli Loyola Gonzaga Mendonça , SP
Co-Authors:
Alberto Hernandez Neto
Presenter: Antonio Luiz Zambelli Loyola Gonzaga Mendonça
doi://10.26678/ABCM.ENCIT2016.CIT2016-0075
Abstract
A demand for finding solutions that can provide better energy use in hotel buildings is increasing, becoming something essential in the reality experienced in this sector in recent times around the world. An increase in energy efficiency of hotels through the application of cogeneration systems is a marked gain in competitiveness, becoming a decisive factor for guests and hotels’ stakeholders, as well as a contribution to the sustainability of the enterprise. In order to increase energy efficiency in hotel buildings, this paper aims to present the technical and economic feasibility of a cogeneration system using absorption refrigeration cycle applied to hotel air conditioning system. In the analysis performed in this paper, it took into account the sector's conditions in Brazilian cities, based on the fact that these cities receive an increasing number of tourists every year, both for cultural events and for business, and need to find solutions to reduce their electrical consumption. Moreover, in recent years, Brazil has been experiencing a significant increase in the cost of electricity. The Brazilian energy matrix is still counting on a major portion of electricity generated by hydroelectric power plants, but the use of thermal power plants is increasing in this matrix, in order to offset the reduction in rainfall and the increasing demand of the country for electricity (due to larger industry demand and increasing electrification across the country). It is therefore necessary to seek alternative sources for energy production as well as encouraging the use of cogeneration systems through more efficient generation and energy conversion. Hotels have strong potential for application of cogeneration systems precisely because it has several energy appliances’ needs (both thermal and electrical). From the modeling of all components forming part of a cogeneration system such as the combustion chamber, turbine, steam boiler and absorption chiller, a study has been made using the variables that can provide a greater influence on the maximum condition efficiency of the system as a whole. It is noteworthy that climatic, seasonal factors, fluctuations in availability and cost of energy sources (whether renewable or not) are part of the local reality, and must be taken into consideration in this study. For the scope of this paper, an absorption refrigeration cycle that uses a mixture of ammonia and water (NH3 + H2O) has been studied. The burning of liquefied petroleum gas inside the combustion chamber as a primary energy of the system was considered to meet the absorption refrigeration cycle demand for thermal energy inside the generator. Factors that may help to reduce the electrical consumption of the building will be presented, thus reducing the dependence of electricity and allowing the use of alternative fuels. In addition, the interactions between the various components that make up the cogeneration system, coupled with the varying energy consumption in a hotel building (such as HVAC, use of hot water in showers, electricity) will be assessed in order to optimize the energy efficiency of the whole building.
Keywords
hotel, cogeneration, Optimization, Absorption refrigeration
