Papers by Alberto Coronas
Journal of Chemical & Engineering Data, 2003
Liquid densities and heat capacities at 1 MPa, and kinematic viscosities at atmospheric pressure ... more Liquid densities and heat capacities at 1 MPa, and kinematic viscosities at atmospheric pressure of monoethylene glycol diethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, triethylene glycol dibutyl ether, and dipropylene glycol dimethyl ether ...
Vapor pressure of H2O+NaNO3 and H2O+NaNO2 solutions were measured with static method from 298.1 t... more Vapor pressure of H2O+NaNO3 and H2O+NaNO2 solutions were measured with static method from 298.1 to 353.1K in a range of salt mass fractions between 0.05 and 0.50. As well, the vapor pressure was determined for quaternary mixtures LiNO3+NaNO3+KNO3+H2O (salt mass ratio 53:5:42) and LiNO3+KNO3+NaNO2+H2O (salt mass ratio 53:35:12) from 313.1 to 353.1K and total salt mass fraction of 0.30, 0.40
Journal of Chemical & Engineering Data, 2008
ABSTRACT
Industrial & Engineering Chemistry Research, 2011
New simple and accurate correlations of the equilibrium properties and solution enthalpies for NH... more New simple and accurate correlations of the equilibrium properties and solution enthalpies for NH 3 /H 2 O/alkaline hydroxide mixtures are presented for use in the modeling and design of absorption chillers in a temperature range between 273.15 and 353.15 K. The correlations are used to calculate the PÀTÀx diagrams and show the effect of hydroxide on the liquidÀvapor equilibrium. Finally, the correlations presented are used to estimate the improvement in the cycle performance in absorption chillers when NH 3 /H 2 O mixtures containing NaOH are used instead of the conventional NH 3 /H 2 O mixture. Results show that the addition of hydroxide can significantly decrease the generator temperature of ammonia/water absorption refrigeration cycles while simultaneously increasing the Coefficient of Performance (COP). For a NaOH concentration of 12%, the temperature at the generator decreases by about 17°C, the COP increases by 28%, and the size of the rectifier can be up to 46% less than that required when the conventional NH 3 /H 2 O cycle is used.
International Journal of Refrigeration, 2009
Additive Hydroxide Sodium Simulation Performance COP a b s t r a c t Adding NaOH to ammonia/water... more Additive Hydroxide Sodium Simulation Performance COP a b s t r a c t Adding NaOH to ammonia/water improves the separation of ammonia in the generator and reduces both chiller driving temperature and rectification losses. In this paper the main disadvantages for the implementation of these new mixtures are addressed: a) few experimental data or reliable correlations of the fluid mixture properties exist; b) selection of an adequate system for separating the hydroxide; and c) evaluation of potential corrosion problems. Our results show that the separation of NaOH from an ammonia/water solution with a maximum approximate mass fraction of 0.05 (5% weight) is viable when reverse osmosis is used with membranes BW30 and SW30HR LE. Cycle simulation using experimental data to calculate the vapour-liquid equilibrium properties shows that the COP is approximately 20% higher than with a conventional ammonia/water chiller working under the same conditions and using a hydroxyl separation efficiency of 99% for NaOH, which is feasible according to the experimental tests. (J.C. Bruno). w w w . ii fi i r .o r g a v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / i j r e f r i g 0140-7007/$ -see front matter ª i n t e r n a t i o n a l j o u r n a l o f r e f r i g e r a t i o n 3 2 ( 2 0 0 9 ) 5 7 7 -5 8 7
International Journal of Refrigeration, 2010
M. Bourouis).
International Journal of Thermophysics, 1994
Densities and kinematic viscosities of trifluoroethanol + water, tetraethylene glycol dimethyleth... more Densities and kinematic viscosities of trifluoroethanol + water, tetraethylene glycol dimethylether + water, and trifluoroethanol + tetraethylene glycol dimethylether have been measured at 303.15 K and atmospheric pressure over the entire range of composition. Dynamic viscosities, excess volumes, excess viscosities, and excess Gibbs energies of activation of flow were obtained from the experimental results. The excess volumes were negative, whereas
Ammonia + water + sodium hydroxide and ammonia + water + potassium hydroxide mixtures were chosen... more Ammonia + water + sodium hydroxide and ammonia + water + potassium hydroxide mixtures were chosen as potential candidates for absorption chillers driven by low-temperature heat sources. Heat capacity and density were studied between (293.15 and 353.15) K at a constant pressure of 1.8 MPa for these solutions using a heat flux Calvet-type calorimeter and a vibrating-tube densimeter, respectively. Measured data were well-correlated with temperature and composition using simple polynomial equations. The relative deviations between the experimental and calculated values in the density and heat capacity measurements were 0.20 % and 0.49 % for NH 3 + H 2 O + NaOH solutions and 0.10 % and 0.36 % for NH 3 + H 2 O + KOH solutions, respectively. Also, two density prediction methods were checked using the experimental data. Previously, it was necessary to measure the density of ammonia and hydroxide aqueous solutions in similar conditions. The results showed that both methods are suitable for predicting the density of these solutions.
Absorption chillers can help to increase the performance of biogas-driven micro gas turbine (MGT)... more Absorption chillers can help to increase the performance of biogas-driven micro gas turbine (MGT) cogeneration plants. In this paper we analyse various integrated configurations of several types of commercially available absorption cooling chillers and MGT cogeneration systems driven by biogas. MGTs are fuelled with biogas and their waste heat is used to drive absorption chillers and other thermal energy users. The chillers considered in this study include single-and double-effect water/LiBr and ammonia/ water chillers. The exhaust gas from the MGT can be used directly to drive the chiller or indirectly to produce hot water to drive the chiller. In this paper we conduct a case study for an existing sewage treatment plant. Chilled water is used to reduce humidity in the biogas pre-treatment process and cool the combustion air of the MGT. We identify the most interesting integrated configurations for trigeneration systems that use biogas and micro gas turbines. We analyse these configurations and compare them with conventional configurations using operational data from an existing sewage treatment plant. The best configurations are those that completely replace the existing system with a trigeneration plant that uses all the available biogas and additional natural gas to completely meet the heating demands of the sewage treatment plant.
The waste heat recovered from small PEMFC (a few kW) could be recovered to produce chilled water ... more The waste heat recovered from small PEMFC (a few kW) could be recovered to produce chilled water for air conditioning during the summer period. Recently small scale sorption chillers have been developed that are able to produce chilled water at these small capacities suitable to integrate these chillers with PEMFC for low capacity trigeneration systems. The main advantage of these trigeneration systems is the production of cooling using waste heat at very low temperature (60-70 ºC) instead of electricity, a high quality and economic cost energy. The objective of this paper is to evaluate the performance of a PEMFC of 5 kW tested in the laboratories of INTA (Huelva) integrated with an adsorption thermally driven chiller of 5 kW of cooling capacity. The results show a good match of capacities and temperatures between available and required thermal energy. To demonstrate the viability of these trigeneration systems it is presented a case study to cover the electricity, heating and cool...
International Journal of Thermal Sciences, 2005
In air-cooled water–LiBr absorption chillers the working conditions in the absorber and condenser... more In air-cooled water–LiBr absorption chillers the working conditions in the absorber and condenser are shifted to higher temperatures and concentrations, thereby increasing the risk of crystallisation. To develop this technology, two main problems are to be addressed: the availability of new salt mixtures with wider range of solubility than water–LiBr, and advanced absorber configurations that enable to carry out simultaneously
International Journal of Refrigeration-revue Internationale Du Froid, 2003
Most water–lithium bromide (LiBr) absorption chillers have a purge system to remove non-absorbabl... more Most water–lithium bromide (LiBr) absorption chillers have a purge system to remove non-absorbable gases that cause a reduction in cooling capacity. Generally, the non-absorbables are originated in corrosion/passivation processes inside the machine, but leaks can also be a source of concern. However, since leaks must be corrected immediately to avoid machine deterioration, this study is mostly aimed at the non-absorbables
Applied Energy, 2001
At present, much interest is being shown in absorption refrigeration cycles driven by low tempera... more At present, much interest is being shown in absorption refrigeration cycles driven by low temperature heat sources, such as solar energy or low-grade waste-heat. Double-lift absorption cycles working with ammonia-water have been recommended for refrigeration applications which require cold at 0°C and which are activated by waste heat between 70 and 100°C. This paper discusses the potential of the organic
2012 2nd International Symposium On Environment Friendly Energies And Applications, 2012
ABSTRACT In this paper, we analyze long-term data of solar radiation, spanning a period of 23 yea... more ABSTRACT In this paper, we analyze long-term data of solar radiation, spanning a period of 23 years, of the town of Adrar located in the western south of Algeria to evaluate technical-economic feasibility of using a photovoltaic system. The aim is to answer at load demand of a typical residential house with the annual electric energy demand of 8000kWh, an average calculated according to a study made by the Algerian government and to limit carbon emissions. Simulation results using the Hybrid Optimization Model for Electric Renewable (HOMER) software is proposed. The optimization modeling demonstrates that 100% of power demand can be supplied by a PV configuration composed of 8kW PV system together with battery storage of 37.5h of autonomy. The PV penetration is 146%, the cost of generating energy from the considered PV system has been found to be 0.46 $/kWh. It is shown that with the proposed photovoltaic system, approximately 11 tons/year of the carbon emissions entering the atmosphere can be reduced for one house only.
Applied Thermal Engineering, 2000
A detailed parametric analysis is carried out on both simple and GAX based combined power and coo... more A detailed parametric analysis is carried out on both simple and GAX based combined power and cooling cycle. The effect of various parameters such as heat source temperature, refrigeration temperature, sink temperature, split ratio (refrigerant flow ratio between power and cooling systems), split factor (solution flow ratio between absorber and GAX heat exchanger) on the performance of the cycle is
In the last few years, high-energy consumption due to air-conditioning has led to a growing inter... more In the last few years, high-energy consumption due to air-conditioning has led to a growing interest in the efficient use of energy in buildings. Although simulation programs have always been the main tools for analyzing energy in buildings, the reliability of their results is often compromised by a lack of certainty to reflect real conditions. The aim of this work
Renewable and Sustainable Energy Reviews, 2010
Journal of Chemical & Engineering Data, 1994
Densities, kinematic viscosities, and excess molar enthalpies have been determined for methanol +... more Densities, kinematic viscosities, and excess molar enthalpies have been determined for methanol + polyethylene glycol 250 dimethyl ether at 303.15 K over the entire range of composition and a t atmospheric pressure. Experimental viscosities were correlated by the McAllister, Stephan, Soliman, and Marshall correlations.
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Papers by Alberto Coronas