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Adsorption refrigeration, as a renewable cooling method, has received more attention in the last few years. The interest in this technology comes especially from developing and tropical countries, where the demand for cooling increases every year due to economy and population growth. Based on this scenario, this work aims to develop a numerical model of an adsorption chiller driven with solar energy, which can be used to optimize the cooling system operation of the building where the device is situated and compare it with the current cooling methods in use. The numerical study here presented was created using Matlab/Simulink™, it is based on a lumped parameter model that relies on physical properties and represents a cooling system using a pair of silica gel-water in a two-bed chiller. In this study, the authors proposed a simplified version of the system and the numerical model, which aims to reduce the simulation time and provide faster results. Besides the temperatures in the system, which range from 52 °C to 72 °C in the hot cycle and 12 °C to 23 °C in the chilled water cycle, the results also include the variation of water uptake in the two adsorbent beds. In general, the simulated temperature, cooling and heating power and coefficient of performance (COP) are in fair agreement with the literature data, nevertheless, the final results show that improvements still have to be performed.

This paper is devoted to study the electrochemical behavior of Pt catalyst in a polymer electrolyte fuel cell at various operating conditions and at different electric potential difference (also known as voltage) cycling applied in accelerated stress tests. The degradation of platinum is considered with respect to the Pt ion dissolution and the Pt oxide coverage of catalyst described by a one-dimensional model. In the model, degradation rate increases with temperature and decreasing particle diameter of Pt nano-particles. The theoretical study of the underlying diffusion system with the nonlinear reactions is presented by analytical methods and gives explicit solutions through a first integral of the ODE system. Numerical tests are obtained using a second order implicit-explicit scheme. The computer simulation shows that the lifetime of the catalyst depends on the voltage profile and the upper potential level. By this Pt mass loss is more significant at the membrane surface than at the gas diffusion layer.

The automated toolkit for assessing environmental and investment attractiveness of a mining region and the results of its application are discussed in the article. This toolkit includes the optimization mathematical model, the algorithms for the interaction between a regional control center and a producer within the territory, as well as the automated software package for their analysis. The use of the optimization mathematical model makes it possible to take into account the maximum economic potential of a producer, which determines, respectively, a mining region’s environment pollution potential. Accounting for environmental risks will allow the control center or other decision makers to identify not only the optimal pattern of eco-economic interaction in the region, but also reflect changes in the environmental and investment climate as a combination of economic potential and involved risks. The model and the algorithms of interaction between a regional control center and a producer, as well as the results of their numerical analysis given in this paper, allow considering this toolkit as an effective decision support tool aimed at improving environmental and investment attractiveness of a mining region by encouraging a producer to use the best available technologies and conserve the natural environment.

Abstract This study utilizes a panel data set from 14 European countries over the period 1990–2004 to estimate a dynamic model specification for gasoline demand. Previous studies estimating gasoline consumption per total passenger cars ignore the recent increase in the number of diesel cars in most European countries leading to biased elasticity estimates. We apply several common dynamic panel estimators to our small sample. Results show that specifications neglecting the share of diesel cars overestimate short-run income, price and car ownership elasticities. It appears that the results of standard pooled estimators are more reliable than common IV/GMM estimators applied to our small data set.

This paper deals with electric arc furnace off‐gas heat recovery and first experiences with a testing plant. The testing plant based on molten salt as heat transfer fluid was installed inside the existing off‐gas system of a German mini mill. Targets of the testing plant are to evaluate tube materials and to measure the influence of hot corrosion and dust settlement. First experimental results are presented. Besides experimental measurements numerical simulations were performed. A process simulation was necessary to describe process dynamics. A computational fluid dynamic simulation of the testing heat exchanger was done to calculate the off‐gas flow profile around the heat exchanger.

Energy optimization of a Multiple Effect Evaporator house employed in the concentration of black liquor during Kraft Recovery process of Paper industries is an eye-catching concern pertinent to the present-day energy scenario. This article presents a proficient approach to solve the energy optimization problem of Multiple Effect Evaporator via metaheuristic optimizers. The proposed method first transforms the energy balance equations into the objective function to be optimized. Three metaheuristic algorithms viz. Harmony Search, Imperialist Competitive Algorithm and Water Cycle Algorithm have been utilized to carry out the optimization task. These metaheuristic approaches effectively figure out the optimum values of various process parameters including steam consumption, vapor temperatures and liquor flow rates, thereby yielding the optimum Steam Economy. Further, the present work investigates the effect of Boiling Point Elevation on the system performance. The results reveal that the inclusion of Boiling Point Elevation in the mathematical model causes a reduction in Steam Economy by 3.89%. The results also demonstrate the proficiency of these metaheuristic approaches towards the solution of a complex set of simultaneous non-linear algebraic equations. For comparative investigation of these metaheuristic approaches with reference to system performance parameters, tabular, evocative and graphical demonstrations have been utilized. Moreover, with the purpose of validating the strength, efficiency and exploratory capabilities of these metaheuristic algorithms, the acquired optimization results are compared with other competent and eminent algorithms to make a comprehensive evaluation.

In recent years, a wide range of strategies has been implemented in different EU-countries to increase the share of electricity generation from renewable energy sources. This paper evaluates the success of different regulatory strategies. The most important conclusions of this analysis are: (i) regardless of which strategy is chosen, it is of overriding importance that there should be a clear focus on the exclusive promotion of newly installed plants; (ii) a well-designed (dynamic) feed-in tariff system ensures the fastest deployment of power plants using Renewable Energy Sources at the lowest cost to society; (iii) promotion strategies with low policy risks have lower profit requirements for investors and, hence, cause lower costs to electricity customers.

The electrical ageing of photovoltaic modules during extended damp-heat tests at different stress levels is investigated for three types of crystalline silicon photovoltaic modules with different backsheets, encapsulants and cell types. Deploying different stress levels allows determination of an equivalent stress dose function, which is a first step towards a lifetime prediction of devices. The derived humidity dose is used to characterise the degradation of power as well as that of the solar cell's equivalent circuit parameters calculated from measured current–voltage characteristics. An application of this to the samples demonstrates different modes in the degradation and thus enables better understanding of the module's underlying ageing mechanisms. The analysis of changes in the solar cell equivalent circuit parameters identified the primary contributors to the power degradation and distinguished the potential ageing mechanism for each types of module investigated in this paper. © 2016 The Authors. Progress in Photovoltaics: Research and Applications published by John Wiley & Sons Ltd. © 2016 The Authors. Progress in Photovoltaics: Research and Applications published by John Wiley & Sons Ltd. This work was supported in part by the European Commission under FP7 grant N° 262533 SOPHIA (INFRA-2010- 1.1.22_CP-CSA-Infra) and by the Research Councils UK (RCUK) under project ‘Stability and Performance of Photovoltaics (STAPP)’ (contract no: EP/H040331/1).