VOLUME 5, ISSUE 6, 2014



Aims and Scope
Editorial Board

Volume 5, Issue 6, 2014, pp.i-viii. Download Full Text (PDF)

1. Study of technical feasibility and the payback period of the invested capital for the installation of a grid-connected photovoltaic system at the library of the Technological Federal University of Paraná

Henrique Marin Campos, Ana Katherine Rodríguez Manrique, Bruno Victor Kobiski, Eloy Fassi Casagrande Júnior, Jair Urbanetz Junior

Post-graduation Program on Civil Engineering, Technological Federal University of Paraná, Curitiba, Brazil.

Abstract: This article shows the technical feasibility, and the payback period of the capital invested to install a Grid-connected Photovoltaic (PV) system on the rooftop of the library of the Technological Federal University of Parana (UTFPR), Curitiba campus. The rooftop has 897 square meters, and the photovoltaic modules will be used to supply electricity to four consumption scenarios. It is hoped that with the normative resolution 482 of the National Agency of Electric Energy (ANEEL), published in April 2012, the payback period on the initial investment of the PV system is shorter than when there was no such resolution. It is known that, although the resolution represents a breakthrough for inserting the Grid-connected Photovoltaic power generation, it is still not enough to expand this technology. The high tax of the PV equipment and the absence of incentives for this form of generation still prevent large-scale use. In addition, this article also shows the PV systems installed in Florianópolis (LABSOLAR / UFSC) and Curitiba, such as the Green Office (GO), which is situated at the Technological Federal University of Parana.

Volume 5, Issue 6, 2014, pp.643-654.

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2. Exergy analyses of an endoreversible closed regenerative Brayton cycle CCHP plant

Bo Yang1,2,3, Lingen Chen1,2,3, Yanlin Ge1,2,3, Fengrui Sun1,2,3

1 Institute of Thermal Science and Power Engineering, Naval University of Engineering, Wuhan 430033, P. R. China.

2 Military Key Laboratory for Naval Ship Power Engineering, Naval University of Engineering, Wuhan 430033, P. R. China.

3 College of Power Engineering, Naval University of Engineering, Wuhan 430033, P. R. China.

Abstract: An endoreversible closed regenerative Brayton cycle CCHP (combined cooling, heating and power) plant coupled to constant-temperature heat reservoirs is presented using finite time thermodynamics (FTT). The CCHP plant includes an endoreversible closed regenerative Brayton cycle, an endoreversible four-heat-reservoir absorption refrigerator and a heat recovery device of thermal consumer. The heat-resistance losses in the hot-, cold-, thermal consumer-, generator-, condenser-, evaporator- and absorber-side heat exchangers and regenerator are considered. The performance of the CCHP plant is studied from the exergetic perspective, and the analytical formulae about exergy output rate and exergy efficiency are derived. Through numerical calculations, the pressure ratio of regenerative Brayton cycle is optimized, the effects of heat conductance of regenerator and ratio of heat demanded by the thermal consumer to power output on dimensionless exergy output rate and exergy efficiency are analyzed.

Volume 5, Issue 6, 2014, pp.655-668. Download Full Text Article (PDF)

3. Modeling the importance of biomass qualities in biomass supply chains for bioenergy production

T.P. Upadhyay, J. H. Greibrokk

University of Tromsř –Arctic University of Norway, School of Business and Economics, Campus Alta, Follumsvei 31, N-9509 Alta, Norway.

Abstract: A tactical-operational level quantitative model can be an important decision support tool for bioenergy producers. Goal programming approach can help analyze the costs and volume implications of various competing goals in terms of biomass characteristics on part of the bioenergy producers. One cost and six quality characteristics goals, namely moisture and ash contents, and thermal values of two types of biomass (forest harvest residue and un/under-utilized species) are selected for the four bioenergy producers in northwestern, Ontario, Canada. We run four models cenarios: i) benchmark total cost and ceilings of mean values of six biomass qualities (Initial Goals), ii)relaxing the quality goals by 10% from the Initial Goals scenario, iii) increasing the conversion efficiency by 10%, and iv) all goals as in Initial Goals except the Atikokan Generating Station (AGS)being supplied with only un/under-utilized biomass. The smaller power plants have relatively less per unit biomass procurement cost. While per unit procurement costs increased, the total costs and biomass volume required to produce the same amount of bioenergy for each power plant decreased in all scenarios compared to the benchmark costs. The goal programming approach, and the results thereof are found to be useful in making effective decisions in the biomass supply chains for bioenergy production.

Volume 5, Issue 6, 2014, pp.669-678. Download Full Text Article (PDF)

4. Monitoring of air pollution spread on the car-free day in the city of Veszprém

Georgina Nagy, Anna Merényi, Endre Domokos, Ákos Rédey, Tatiana Yuzhakova

Institute of Environmental Engineering, Faculty of Engineering, University of Pannonia, 10 Egyetem St., Veszprém, Hungary H-8200.

Abstract: One of the major factors which adversely affect environmental quality in many cities all over the world is air pollution, with profound negative effects on human health [1]. Apart from the health risks through the inhalation of gases and particles, urban air pollution is the source of other problems such as accelerated corrosion and deterioration of materials, damage to historical monuments and buildings and damage to vegetation in and around the city [2]. In this study, we aimed to investigate the effect of the vehicle related emissions which are a significant source of air pollutants. The research was conducted during the European Mobolity Week (EMW) on the Car-Free Day (CFD). For the characterization of the air quality the generally accepted indicators – O3, CO, SO2, NO/NO2/NOx, PM10, Benzene (B), Toluol (T), Etil-benzene (E), m-, p-Xilol (MP), o-Xilol (O)  concentrations – were used, which well characterizes the changes in air pollution. The average concentrations measured on the car free day  for  O3 was 64,5 µg/m3, for NO2 was 6,76 µg/m3, for CO was 127,12 µg/m3, for SO2 was 5,19 µg/m3, for PM10 was 10,88 μg/m3, for Benzene was 0,38 µg/m3, for Toluol was 0,58 µg/m3, for Etil-benzene was 0,22 µg/m3, for MP-Xilol was 1,64 µg/m3 and for O-Xilol was 2,93 µg/m3. The results clearly shows that the daily fluctuation of the air pollutants depending on the traffic.

Volume 5, Issue 6, 2014, pp.679-684. Download Full Text Article (PDF)

5. Transient thermal behavior of a homogeneous composite micro-domain: The hyperbolic heat-conduction model

Faisal M. AL- Ghathian

Faculty of Engineering Technology, Al-Balqa' Applied University, P.O. Box 179, Tafila, 66110, Jordan.

Abstract: The transient thermal behavior of a homogeneous composite micro-domain described by the hyperbolic heat-conduction model with neglecting conduction in the fluid domain is investigated semi-analytically. The composite micro-domain consists of a matrix (fluid domain) and inserts (solid domain), each made of different material. The effect of different parameters that affect the local thermal equilibrium assumption under the effect of the hyperbolic heat conduction model is investigated.

Volume 5, Issue 6, 2014, pp.685-692. Download Full Text Article (PDF)

6. Model application for acid mine drainage treatment processes

Nantaporn Noosai, Vineeth Vijayan, Khokiat Kengskool

Department of Civil and Environmental Engineering, Florida International University, Miami, FL 33174, USA.

Abstract: This paper presents the utilization of the geochemical model, PHREEQC, to investigate the chemical treatment system for Acid Mine Drainage (AMD) prior to the discharge. The selected treatment system consists of treatment processes commonly used for AMD including settling pond, vertical flow pond (VFP) and caustic soda pond were considered in this study. The use of geochemical model for the treatment process analysis enhances the understanding of the changes in AMD’s chemistry (precipitation, reduction of metals, etc.) in each process, thus, the chemical requirements (i.e., CaCO3 and NaOH) for the system and the system’s treatment efficiency can be determined. The selected treatment system showed that the final effluent meet the discharge standard. The utilization of geochemical model to investigate AMD treatment processes can assist in the process design.

Volume 5, Issue 6, 2014, pp.693-700. Download Full Text Article (PDF)

7. Thermodynamic analysis for a regenerative gas turbine cycle in coking process

Zelong Zhang1, 2, 3, Lingen Chen1, 2, 3,, Yanlin Ge1, 2, 3, Fengrui Sun1, 2, 3

1 Institute of Thermal Science and Power Engineering, Naval University of Engineering, Wuhan 430033, China.

2 Military Key Laboratory for Naval Ship Power Engineering, Naval University of Engineering, Wuhan 430033, China.

3 College of Power Engineering, Naval University of Engineering, Wuhan 430033, China.

Abstract: A regenerative gas turbine cycle driven by residual coke oven gas is proposed in this paper. The thermal efficiency and the work output (per ton of coke) of the system are analyzed based on thermodynamics and the theory of gas turbine cycle. The influences of the gas release rate, the residual gas rate and the effectiveness of regenerator on the performance of the cycle are analyzed by using numerical examples. It is found that the work output increases with the increase of the residual gas rate while decreases with the increase of the gas release rate. The cycle with regenerator can reach higher thermal efficiency and bigger work output, which means that the coke oven gas is used more effectively. Moreover, there exist two optimal pressure ratios of compressor which lead the maximum thermal efficiency and the maximum specific work, respectively.

Volume 5, Issue 6, 2014, pp.701-708. Download Full Text Article (PDF)

8. Thermal insulation capacity of roofing materials under changing climate conditions of Sub Saharan regions of Africa

Julien G. Adounkpe1, Clement Ahouannou2, O. Lie Rufin Akiyo3, Augustin Brice Sinsin1

1 Laboratory of Applied Ecology, Faculty of Agronomic Sciences, University of Abomey Calavi, 03 BP 3908 Cotonou Republique du Benin.

2 Département de Génie Mécanique et Energétique Ecole Polytechnique d’Abomey Calavi, Université d’Abomey Calavi, 03 BP 1175 Cotonou Republique du Benin.

3 Department of Geography of the University of Parakou, Republic of Benin BP 123 Université de Parakou Republic of Benin.

Abstract: Climate change is affecting human indoor thermal comfort. Human habitat roof’s thermal insulation capacity may play key role in reducing the discomfort resulting from climate change. In the present study, six roof materials are analyzed for their thermal insulation capacity: aluminum-iron (Al-Fe) sheet, Al-Fe sheet with outer face white painted, Al-Fe sheet with various straw thick, white tile, red tile and gray tile. Solar radiations, ambient temperature, wind speed, roof inner and indoor temperatures were daily measured during April and June. Measured roof inner wall temperatures for each type of material agreed with the model set forth. The indoor temperature showed, under the same atmospheric conditions, Al-Fe sheet at a maximum of 51.4°C ; Al-Fe sheet with outer face white paint at 40.3°C; Al-Fe sheet with 3cm thick of straw at 41.2°C; and Al-Fe with 6cm thick of straw at 36.8°C, making the latter the better roof at day time. For the inner wall temperatures of the roof without ceilings, Al-Fe sheet has a maximum at 73°C; Al-Fe sheet with outer wall white paint at 48.1°C; Al-Fe sheet with 3cm straw thick at 45.2°C; and Al-Fe with 6cm straw thick at 37.9°C, red tile at 51.3°C; white tile at 41.6°C and grey tile at 51.6°C. This study enlightens the change that can be made on the traditional roof to improve indoor thermal comfort in changing climate conditions.

Volume 5, Issue 6, 2014, pp.709-716. Download Full Text Article (PDF)

9. Material waste in the China construction industry: Minimization strategies and benefits of recognition

Sulala M.Z.F. Al-Hamadani1,2, ZENG Xiao-lan1,2, M.M.Mian1,2, Zhongchuang Liu1,2

1 Three Gorges Reservoir Area’s Ecology and Environment Key Laboratory of Ministry of Education, Chongqing University, Chongqing, 400045, China.

2 National Centre for International Research of Low-carbon and Green Buildings, Chongqing University, Chongqing, 400045, China.

Abstract: Waste minimization strategies and the relative importance of benefits of material waste recognition were examined using a survey of construction companies operating in Chongqing city China. The results showed that a remarkable proportion of respondent companies have specific policies for minimizing construction waste. Amongst the strategies, minimizing waste at source of origin is practiced to a large degree by construction companies with specific waste minimization strategies. However, considerable quantities of construction waste are generated. These quantities need to be reused or recycled or combination of them. The study also revealed that recycling is not highly practiced because it needs a lot of capital and an area, except for those high scrap value recycling materials like steel, whereas other non-profitable will be sent to C&D landfills directly. Respondents’ perceptions towards the benefits of material waste recognition revealed that materials waste is primarily considered an environmental and financial problem and its minimization a cost cutting activity and protection of the environment. In contrast, the contractual benefits were considered less important by surveyed companies.

Volume 5, Issue 6, 2014, pp.717-722. Download Full Text Article (PDF)

10. CFD modeling of dust dispersion through Najaf historic city centre

Maher A.R. Sadiq Al-Baghdadi

CFD Center, International Energy and Environment Foundation, Najaf, P.O.Box 39, Iraq.

Abstract: The aim of this project is to study the influences of the wind flow and dust particles dispersion through Najaf historic city centre. Two phase Computational Fluid Dynamics (CFD) model using a Reynolds Average Navier Stokes (RANS) equations has been used to simulate the wind flow and the transport and dispersion of the dust particles through the historic city centre. This work may provide useful insight to urban designers and planners interested in examining the variation of city breathability as a local dynamic morphological parameter with the local building packing density.

Volume 5, Issue 6, 2014, pp.723-728. Download Full Text Article (PDF)