The purpose and scope of the International Journal of Thermodynamics is to provide a forum for the publication of original theoretical and applied work in the field of thermodynamics as it relates to systems, states, processes, and both non-equilibrium and equilibrium phenomena at all temporal and spatial scales. The journal, thus, provides a multidisciplinary and international platform for the dissemination to academia and industry of both scientific and engineering contributions, which touch upon a broad class of disciplines that are foundationally linked to thermodynamics and the methods and analyses derived there from. A common thread throughout is that of assessing how both the first and particularly the second laws of thermodynamics touch upon these disciplines.
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| Posted: 2013-03-24 |
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Vol 16, No 2: June 2013
Table of Contents
Front Matter
| General Information for Authors |
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Guidelines for formatting and submitting an article to IJoT. |
Invited ECOS 2011 Paper for ECOS Special Issue
| Flameless Oxidation as a Means to Reduce NOx Emissions in Glass Melting Furnaces |
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Jörg Leicher |
55-61 |
In the glass industry, very high process temperatures are required in order to melt the raw materials. These temperature levels are usually achieved by burning natural gas with strongly pre-heated air. However, this creates ideal conditions for a strong formation of nitrous oxides (NOX), a pollutant whose emissions are strictly regulated. The industry is therefore very much interested in technologies to suppress the production of NOX within the furnace itself. One possible approach is the so-called flameless oxidation, a novel combustion regime which is characterized by very homogeneous temperature distributions and low NOX production. While this form of combustion is firmly established in the steel industry, the glass industry has been reluctant to change its production methods as the glass melt is very sensitive to changes in the furnace conditions.
Gas- und Wärme-Institut Essen e.V. (GWI), in cooperation with its partners, investigated how to best introduce flameless oxidation into glass melting furnaces. Using both simulation and experimental techniques, a GlasFLOX burner was developed and then examined with regards to its NOX reduction performance. In a second step, the retrofitting of an operating furnace was carried out, based on a strategy determined by extensive CFD simulations.
After five years of operation, the operators of the retrofitted plant report unchanged product quality, while NOX emissions have been reduced by about 50 %. |
Invited ECOS 2012 Papers
| Performance Estimation and Optimal Operation of a CO2 Heat Pump Water Heating System |
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Ryohei Yokoyama |
62-72 |
The daily performance of a CO2 heat pump water heating system with a hot water storage tank is affected by the history of daily hot water demand and heat pump operating conditions. To attain the maximum system performance, it is important to estimate the daily changes in the system performance values accurately in relation to those in hot water demand and heat pump operating conditions, and determine the operating conditions optimally based on the estimation. In this paper, neural network models are used for this estimation, and the values of model parameters are identified by a global optimization method. In addition, the outlet water temperature for during operation and the inlet water temperature for shutdown are determined to maximize the system efficiency subject to a lower limit for the volume of unused hot water. The validity and effectiveness of this approach are ascertained by a numerical study using a simulated hot water demand. |
| Human Body Exergy Metabolism |
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Carlos Eduardo Keutenedjian Mady |
73-80 |
The exergy analysis of the human body is a tool that can provide indicators of health and life quality. To perform the exergy balance it is necessary to calculate the metabolism on an exergy basis, or metabolic exergy, although there is not yet consensus in its calculation procedure. Hence, the aim of this work is to provide a general method to evaluate this physical quantity for human body based on indirect calorimetry data. To calculate the metabolism on an exergy basis it is necessary to define the reference reactions and obtain their exergy variation. The reference reactions of the energy substrates are represented by the oxidation of the glucose, palmitic acid and a representative amino acid. Hence, from the exergy variation of these reactions and the consumption rate of the substrates, the metabolic exergy is determined. Results, for basal conditions and during physical activities, indicate that the difference between exergy and energy metabolisms is lower than 5%. Moreover, the body converts approximately 60% of the exergy of nutrients into available exergy to perform work. |
| Defossilisation assessment of biodiesel life cycle production using the ExROI indicator |
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Emilio Font de Mora, César Torres, Antonio Valero, David Zambrana |
81-86 |
Ensuring the sustainability of biofuels is a mandatory requisite for the EU Member States. The EU Renewables Directive focused on the reduction of greenhouse gas emissions and the protection of high biodiversity and carbon stock lands. The current framework does not consider the consumption of non-renewable resources. Starting from the paper “Assessment of biodiesel energy sustainability using the ExROI concept” published in Energy, which defined the ExROI (Exergy Return on Investment) indicator and applied it to well-to-tank biodiesel production from rapeseed, sunflower and palm, this paper proposes: extending the use of ExROI, which involves exergy cost accounting, to the life cycle; extending the calculations to soybean and used cooking oil; assessing ways to “defossilise” the cycles. This paper demonstrates that the ExROI is a better indicator than the EROI (Energy Return on Investment) which only considers energy flows. Also, it shows that biodiesel life cycles have positive ExROI values and that the ExROI value can be improved up to 26.51, i.e. for one unit of non-renewable sources invested in the process more than 26 units of biodiesel are obtained. This means that biodiesel can be around five times more sustainable than fossil diesel, from the viewpoint of non-renewable resources consumption. |
| Vegetable Oils of Soybean, Sunflower and Tung as Alternative Fuels for Compression Ignition Engines |
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Ricardo Morel Hartmann, Nury Nieto Garzon, Eduardo Morel Hartmann, Amir Antônio Martins Oliveira, Edson Bazzo |
87-96 |
This paper deals with the use of straight vegetable oil as fuel for compression ignition engine applied to distributed electric generation. It was studied three typical oils from southern of the Brazil, soybean oil, sunflower oil and tung oil. For this purpose it was designed and assembled a conversion kit that allows the use of the selected oils directly in the engine. The kit preheats the fuel to a temperature where their physical properties, mainly viscosity, reaches the diesel oil levels. This kit is electronic controlled and it was used standardized measurements of some physical properties of the fuels, for the design of their control software. The straight vegetables oils, its blends 50/50 v/v with petrodiesel fuel and neat petrodiesel fuel were tested in dynamometer bench. It was obtained results of brake power, torque, specific fuel consumption and emissions as function of the rotation of the engine. The discussions about the results in terms of efficiency first law showed the technical feasibility of the using of straight vegetable oils and the effectiveness of the developed conversion kits. |
ISSN: 2146-1511
