Browsing by Author "Santos, Alexandre F."
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- Análise de temperaturas geotérmicas para aplicação de bombas de calor no ParanáPublication . Santos, Alexandre F.; Souza, Heraldo; Cantão, Mauricio P.; Gaspar, Pedro DinisBombas de calor geotérmicas são muito utilizadas em países desenvolvidos, porém, são pouco utilizadas no Brasil, em parte porque faltam medidas de temperatura do solo brasileiro. Os objetivos deste trabalho são: apresentar medidas de temperatura geotérmica e comparar o desempenho do sistema geotérmico e do sistema convencional de ar condicionado. Apresentam-se resultados da medição de temperatura geotérmica em dez cidades paranaenses, representativas dos diferentes solos e climas. As medições foram realizadas ao longo de um ano, com equipamentos aferidos e sistemas digitais de aquisição de dados nas diferentes estações de medição instaladas. Os dados de temperatura geotérmica e ambiente foram utilizados para simulação do coeficiente de performance (COP), por meio de software de dimensionamento de sistemas em ciclo de refrigeração por compressão de vapor, baseado no diagrama de pressão-entalpia do fluido de rabalho. Verificou-se que a temperatura geotérmica medida entre janeiro e outubro de 2013 variou de 16 a 24 °C, enquanto a temperatura ambiente variou entre 2 e 35 °C. Valores médios de COP para o sistema convencional foram de 3,7 (refrigeração) e 5,0 kW/kW (aquecimento), correspondente a 5,9 e 7,9 para o sistema BCG, o que significa ganho em eficiência de 59% com o uso do sistema geotérmico.
- Analysis of geothermal temperatures for heat pumps application in Paraná (Brasil)Publication . Santos, Alexandre F.; Souza, Heraldo; Cantão, Mauricio P.; Gaspar, Pedro DinisGeothermal heat pumps are broadly used in developed countries but scarcely in Brazil, in part because there is a lack of Brazilian soil temperature data. The aims of this work are: to present soil temperature measurements and to compare geothermal heat pump system performances with conventional air conditioning systems. Geothermal temperature measurement results are shown for ten Paraná State cities, representing different soil and climate conditions. The measurements were made yearlong with calibrated equipment and digital data acquisition system in di erent measuring stations. Geothermal and ambient temperature data were used for simulations of the coe cient of performance (COP), by means of a working uid pressure-enthalpy diagram based software for vapor-compression cycle. It was veri ed that geothermal temperature measured between January 13 to October 13, 2013, varied from 16 to 24 °C, while room temperature has varied between 2 and 35 °C. Average COP values for conventional system were 3.7 (cooling mode) and 5.0 kW/kW (heating mode), corresponding to 5.9 and 7.9 kW/kW for geothermal system. Hence it was verified an average efficiency gain of 59%with geothermal system utilization in comparison with conventional system.
- Ecoenergetic Comparison of HVAC Systems in Data CentersPublication . Santos, Alexandre F.; Gaspar, Pedro Dinis; Souza, Heraldo J. L. deThe topic of sustainability is of high importance today. Global efforts such as the Montreal Protocol (1987) and the Kigali Amendment (2016) are examples of joint work by countries to reduce environmental impacts and improve the level of the ozone layer, the choice of refrigerants and air conditioning systems, which is essential for this purpose. But what indicators are to be used to measure something so necessary? In this article, the types of air conditioning and GWP (Global Warming Potential) levels of equipment in the project phase were discussed, the issue of TEWI (Total Equivalent Warming Impact) that measures the direct and indirect environmental impacts of refrigeration equipment and air conditioning and a new methodology for the indicator was developed, the TEWI DC (DC is the direct application for Data Center), and using the formulas of this new adapted indicator it was demonstrated that the TEWI DC for Chicago (USA) was 2,784,102,640 kg CO2/10 years and Curitiba (Brazil) is 1,252,409,640 kg CO2/10 years. This difference in value corresponds to 222.30% higher annual emissions in Chicago than in Curitiba, showing that it is much more advantageous to install a Data Center in Curitiba than in Chicago in terms of environmental impact. The TEWI indicator provides a more holistic view, helping to combine energy and emissions into the same indicator.
- Evaluation of the heat and energy performance of a datacenter by a new efficiency index: Energy Usage Effectiveness Design - EUEDPublication . Santos, Alexandre F.; Souza, Heraldo; Gaspar, Pedro DinisData Centers are growing steadily worldwide and they are expected to continue on growing up to 53% in 2020. Due to this growth the energy efficiency in this type of building is essential. There are methodologies to measure this efficiency; one example is PUE (Power Usage Effectiveness). The unit suggested for measuring efficiency at the design stage would be the EUED (Energy Usage Efficiency Design) with this will be used data to use "free cooling" and adiabatic system in some cases, a comparison will be made only considering the equipment in the worst situation. It also uses the study of enthalpy utilization as a new methodology to obtain the results. By doing so, differences were found, between cities than 1.21% of São Paulo in relation to Curitiba and 10.61% of Rio de Janeiro in relation to Curitiba. The indices obtained by applying the EUED index were 1.245 kW.kW- 1 for Curitiba, 1.260 kW.kW-1 for São Paulo and 1.377 kW.kW-1 for Rio de Janeiro, respectively, giving a difference of 16.86% for Curitiba of 16.19% for São Paulo and 10.31% for Rio de Janeiro in relation to PUE COA (Power Usage Effectiveness Constant Outdoor Air).
- Evaluation of the Thermal Performance and Energy Efficiency of CRAC Equipment through Mathematical Modeling Using a New Index COP WEUEDPublication . Santos, Alexandre F.; Gaspar, Pedro Dinis; Souza, Heraldo J. L. deAs the world data traffic increasingly grows, the need for computer room air conditioning (CRAC)-type equipment grows proportionally. The air conditioning equipment is responsible for approximately 38% of the energy consumption of data centers. The energy efficiency of these pieces of equipment is compared according to the Energy Standard ASHRAE 90.1-2019, using the index Net Sensible Coefficient Of Performance (NetSCOP). This method benefits fixed-speed compressor equipment with a constant inlet temperature air-cooled condenser (35 C). A new method, COP WEUED (COP–world energy usage effectiveness design), is proposed based on the IPLV (integrated part load value) methodology. The IPLV is an index focused on partial thermal loads and outdoor temperature data variation for air intake in the condenser. It is based on the average temperatures of the USA’s 29 major cities. The new method is based on the 29 largest cities worldwide and with datacenter- specific indoor temperature conditions. For the same inverter compressor, efficiencies of 4.03 and 4.92 kW/kW were obtained, using ASHRAE 90.1-2019 and the proposed method, respectively. This difference of almost 20% between methods is justified because, during less than 5% of the annual hours, the inlet air temperature in the condenser is close to the NetSCOP indication.
- New index for sustainability in climate control - TWI (Total Water Impact)Publication . Santos, Alexandre F.; Gaspar, Pedro DinisSales for air conditioning are growing rapidly in buildings, more than tripling between 1990 and 2016. This energy use for air conditioning comes from a combination of rising temperatures, rising population and economic growth. Energy demand for climate control will triple by 2050, consuming more energy than the United States, the European Union and Japan today. This increase in energy will directly impact water consumption, either to cool a condenser of equipment directly or to serve indirectly as a basis for energy sources such as hydroelectric power that feed into these HVAC systems. Knowing the unique and growing importance of water, a new index, Total Water Impact (TWI) is presented, which allows a holistic comparison of the impact of water use on water, air and evaporative condensation climate systems.