PubAg

Main content area

Search

76  Search Results

« Previous | 1 - 20 of 76 |
Number of results to display per page

Search Results

1. A facility-location model for biofuel plants: Applications in the Colombian context

Author:
Duarte, Alexandra E.; Sarache, William A.; Costa, Yasel J.
Source:
Energy 2014 v.72 pp. 476-483
ISSN:
0360-5442
Subject:
agricultural wastes; bioethanol; consumers (people); linear programming; models; operating costs; process design; profitability; stems; supply chain; Colombia
Abstract:
... To reduce the logistical and operating costs for biofuel plants, it is important to make a strategic decision to select the proper site for a new facility. Due to the facility's complexity, the facility-location problem must consider the supply-chain structure, involving the material flow from suppliers to customers. This paper proposes an optimisation framework that combines the process design an ...
DOI:
10.1016/j.energy.2014.05.069

2. Analysis of regulation methods of a combined heat and power plant based on gas turbines

Author:
Jiménez-Espadafor Aguilar, Francisco; Quintero, R. Rodríguez; Trujillo, E. Carvajal; García, Miguel Torres
Source:
Energy 2014 v.72 pp. 574-589
ISSN:
0360-5442
Subject:
cogeneration systems; electric power; energy conservation; energy efficiency; generators (equipment); heat recovery; models; oils; power plants; steam; turbines
Abstract:
... This paper addresses the study of eight different regulation methods on a cogeneration plant integrated by two gas turbines model LM2500 coupled to an HRSG (heat recovery steam generator), which provides steam at high and medium pressure and thermal oil. This study is aimed at showing the capacity of each regulation method meaning the range of thermal power that is available for a given electrical ...
DOI:
10.1016/j.energy.2014.05.083

3. Analysis of the integrated characteristics of the CPS (combined power system) of a bottoming organic Rankine cycle and a diesel engine

Author:
Yue, Chen; Han, Dong; Pu, Wenhao
Source:
Energy 2014 v.72 pp. 739-751
ISSN:
0360-5442
Subject:
air flow; corrosion; dewpoint; diesel engines; heat transfer; models; temperature
Abstract:
... This study analyses the integrated characteristics of a CPS (combined power system) consisting of a topping diesel engine and a bottoming ORC (organic Rankine cycle). Two models (an integrated and a cascaded CPS model) for the same CPS have been developed based on the experimental data. The results show that the process of integrating the ORC causes a substantial decrease in the power output of th ...
DOI:
10.1016/j.energy.2014.05.103

4. An important feature of air heat pump cycle: Heating capacity in line with heating load

Author:
Zhang, Chun-Lu; Yuan, Han
Source:
Energy 2014 v.72 pp. 405-413
ISSN:
0360-5442
Subject:
air; carbon dioxide; energy efficiency; heat pumps; temperature; thermodynamic models
Abstract:
... In the conventional vapor-compression heat pumps, the heating capacity and the heating load usually vary in opposite directions, which results in a mismatch of the heating capacity and the heating load at off-design conditions. Air (reversed Brayton) cycle is a potential substitute for the conventional vapor-compression cycles. This paper proved that in theory the air heat pump cycle can make the ...
DOI:
10.1016/j.energy.2014.05.055

5. An integrated optimization for organic Rankine cycle based on entransy theory and thermodynamics

Author:
Li, Tailu; Fu, Wencheng; Zhu, Jialing
Source:
Energy 2014 v.72 pp. 561-573
ISSN:
0360-5442
Subject:
engineering; entropy; evaporation; heat; mass flow; mathematical models; system optimization; temperature; thermal conductivity
Abstract:
... The organic Rankine cycle has been one of the essential heat-work conversion technologies nowadays. Lots of effectual optimization methods are focused on the promotion of the system efficiency, which are mainly relied on engineering experience and numerical simulations rather than theoretical analysis. A theoretical integrated optimization method was established based on the entransy theory and th ...
DOI:
10.1016/j.energy.2014.05.082

6. A novel distributed optimal power sharing method for radial dc microgrids with different distributed energy sources

Author:
Asad, R.; Kazemi, A.
Source:
Energy 2014 v.72 pp. 291-299
ISSN:
0360-5442
Subject:
electric power; energy; prices
Abstract:
... DC microgrids will be an important part of the future electrical power systems, i.e., smart grids. Similar to the other power systems, one of the important issues of dc microgrids is the fulfillment of the optimal power sharing. In this paper, a practical, modular, robust, highly reliable, autonomous, distributed, optimal power sharing method, namely the ODCPS (optimal dc power sharing) method, is ...
DOI:
10.1016/j.energy.2014.05.036

7. Are structural change and modernisation leading to convergence in the CO2 economy? Decomposition analysis of China, EU and USA

Author:
Kaivo-oja, J.; Luukkanen, J.; Panula-Ontto, J.; Vehmas, J.; Chen, Y.; Mikkonen, S.; Auffermann, B.
Source:
Energy 2014 v.72 pp. 115-125
ISSN:
0360-5442
Subject:
European Union; business enterprises; carbon dioxide; energy; fuel combustion; globalization; greenhouse gas emissions; modernization; China; United States
Abstract:
... This article investigates the factors that impact the amount of CO2 emissions from fuel combustion and energy use in three major economies in the world, China, the EU-27 and the United States, using mathematical decomposition analysis, where the observed change in explained variable is divided into meaningful components. These components' shares of the total change can be compared and the change i ...
DOI:
10.1016/j.energy.2014.05.015

8. A three-dimensional transient model for EGS subsurface thermo-hydraulic process

Author:
Jiang, Fangming; Chen, Jiliang; Huang, Wenbo; Luo, Liang
Source:
Energy 2014 v.72 pp. 300-310
ISSN:
0360-5442
Subject:
heat transfer; models; rocks
Abstract:
... Understanding the subsurface thermo-hydraulic process in enhanced or engineered geothermal systems (EGS) is crucial to the efficiency of heat extraction and the sustainable utilization of geothermal reservoir. We present in detail a three-dimensional transient model for the study of subsurface thermo-hydraulic process during EGS heat extraction and demonstrate its capability through test simulatio ...
DOI:
10.1016/j.energy.2014.05.038

9. Banking development and energy consumption: Evidence from a panel of Middle Eastern countries

Author:
Aslan, Alper; Apergis, Nicholas; Topcu, Mert
Source:
Energy 2014 v.72 pp. 427-433
ISSN:
0360-5442
Subject:
banking; economic development; energy; energy conservation; energy costs; energy use and consumption; environmental policy; income; supply balance; Middle East
Abstract:
... Since the late 1990s, much scholarly work has been done in the field of energy economics on the nexus between economic growth and energy consumption. Over the last decade, however, the literature has been recompiled through examining the relationship between energy consumption and a set of variables by referring to the implicit role of economic growth. Based upon finance-energy nexus, this paper a ...
DOI:
10.1016/j.energy.2014.05.061

10. Bio-lubricant-biodiesel combination of rapeseed oil: An experimental investigation on engine oil tribology, performance, and emissions of variable compression engine

Author:
Arumugam, S.; Sriram, G.; Ellappan, R.
Source:
Energy 2014 v.72 pp. 618-627
ISSN:
0360-5442
Subject:
aluminum; ash content; biolubricants; cupric oxide; diesel engines; emissions; epoxidation reactions; esterification; fluid mechanics; hydroxylation; iron; petroleum; rapeseed oil; soot
Abstract:
... The substitution of petroleum based synthetic lubricant with rapeseed oil based bio-lubricant in a variable compression ratio diesel engine is explored in this study. Rapeseed oil based bio-lubricant was formulated through chemical modifications like epoxidation, hydroxylation and esterification process for improving its thermo-oxidative stability and cold flow properties. The nano CuO (copper oxi ...
DOI:
10.1016/j.energy.2014.05.087

11. Chemisorption cooling and electric power cogeneration system driven by low grade heat

Author:
Bao, Huashan; Wang, Yaodong; Charalambous, Constantinos; Lu, Zisheng; Wang, Liwei; Wang, Ruzhu; Roskilly, Anthony Paul
Source:
Energy 2014 v.72 pp. 590-598
ISSN:
0360-5442
Subject:
activated carbon; adsorbents; adsorption; calcium chloride; cooling; electric power; heat; prototypes; refrigeration; system optimization; temperature
Abstract:
... A novel integration of chemisorption refrigeration cycle and a scroll expander was investigated for the cogeneration of cooling and electric power. The first lab prototype machine has been built, and the two main components were tested both independently and cooperatively for comparison before and after the integration therefore leading to better knowledge of the interaction between them. Two sets ...
DOI:
10.1016/j.energy.2014.05.084

12. Coastal impact assessment of a generic wave farm operating in the Romanian nearshore

Author:
Tănase Zanopol, Andrei; Onea, Florin; Rusu, Eugen
Source:
Energy 2014 v.72 pp. 652-670
ISSN:
0360-5442
Subject:
absorption; climate; drilling; farms; mathematical models; Black Sea; Danube River
Abstract:
... The present work is focused on the evaluation of the coastal impact of a generic wave farm that would operate in the Romanian nearshore. The target area considered for analysis is located in the Black Sea, in the vicinity of the Saint George arm of the Danube River, which is a sector where the erosion processes are very high. A first perspective concerning the wave conditions close to this coastal ...
DOI:
10.1016/j.energy.2014.05.093

13. Combustion and emission characteristics of a DME (dimethyl ether)-diesel dual fuel premixed charge compression ignition engine with EGR (exhaust gas recirculation)

Author:
Zhao, Yuwei; Wang, Ying; Li, Dongchang; Lei, Xiong; Liu, Shenghua
Source:
Energy 2014 v.72 pp. 608-617
ISSN:
0360-5442
Subject:
carbon monoxide; combustion; emissions; energy use and consumption; fuels; heat; hydrocarbons; nitrogen oxides; smoke; temperature
Abstract:
... In this study, effects of DME (dimethyl ether) pre-mixing ratio and cooled external EGR (exhaust gas recirculation) rate on combustion, performance and emission characteristics of a DME-diesel dual fuel PCCI (premixed charge compression ignition) engine were investigated in a 2105 engine. PCCI combustion at a high pre-mixing ratio exhibited a three-stage-combustion behavior. The peak values of hea ...
DOI:
10.1016/j.energy.2014.05.086

14. Combustion of CH4/O2/N2 in a well stirred reactor

Author:
Wang, Feifei; Li, Pengfei; Mei, Zhenfeng; Zhang, Jianpeng; Mi, Jianchun
Source:
Energy 2014 v.72 pp. 242-253
ISSN:
0360-5442
Subject:
combustion; methane; nitrogen; physicochemical properties; temperature; tin
Abstract:
... Detailed kinetic calculations of chemical reactions using GRI-Mech 3.0 are carried out to characterize the combustion of CH4/O2/N2 mixture in a well-stirred reactor (WSR). Very wide ranges of the inlet temperature Tin (300 K–2700 K), nitrogen dilution concentration (0%–99%) and global equivalence ratio (0.5–4.0) are considered. The extinction and self-ignition temperatures (Tex and Tsi) of the CH4 ...
DOI:
10.1016/j.energy.2014.05.029

15. Comparison of closed and open thermochemical processes, for long-term thermal energy storage applications

Author:
Michel, Benoit; Neveu, Pierre; Mazet, Nathalie
Source:
Energy 2014 v.72 pp. 702-716
ISSN:
0360-5442
Subject:
heat; models; thermal energy; vapors
Abstract:
... This paper focuses on the study of a solid/gas thermochemical reaction between a porous reactive bed and vapor. The objective is to determine the operating mode, either closed or open system, that best suits the requirements of a thermochemical seasonal storage applied to house heating. These two working modes have been compared thanks to two validated 2D models. This study shows that for the chos ...
DOI:
10.1016/j.energy.2014.05.097

16. Comparison of particle swarm optimization and other metaheuristics on electricity demand estimation: A case study of Iran

Author:
Askarzadeh, Alireza
Source:
Energy 2014 v.72 pp. 484-491
ISSN:
0360-5442
Subject:
algorithms; birds; case studies; electricity; energy; energy policy; models; planning; social behavior; socioeconomics; Iran
Abstract:
... The importance of energy demand estimation stems from energy planning, formulating strategies and recommending energy policies. Most often, energy demand is mathematically formulated by socio-economic indicators. The challenging problem is to determine the optimal or near optimal weighting factors. Inspired by social behavior of bird flocking or fish schooling, PSO (particle swarm optimization) is ...
DOI:
10.1016/j.energy.2014.05.070

17. Degradation analysis of a-Si, (HIT) hetro-junction intrinsic thin layer silicon and m-C-Si solar photovoltaic technologies under outdoor conditions

Author:
Sharma, Vikrant; Sastry, O.S.; Kumar, Arun; Bora, Birinchi; Chandel, S.S.
Source:
Energy 2014 v.72 pp. 536-546
ISSN:
0360-5442
Subject:
climatic factors; coatings; glass; oxidation; silicon; silver; solar energy; thermography; India
Abstract:
... Understanding degradation mechanism is of utmost importance for long term reliability of photovoltaic technology. In the present study, degradation analysis of three different photovoltaic technology modules namely a-Si (amorphous single junction silicon), HIT (hetro-junction intrinsic thin layer silicon) and m-C-Si (multi-crystalline silicon) is carried out after 28 months of outdoor exposure at ...
DOI:
10.1016/j.energy.2014.05.078

18. Development and testing of a hybrid system with a sub-kW open-cathode type PEM (proton exchange membrane) fuel cell stack

Author:
Huang, Zhen-Ming; Su, Ay; Liu, Ying-Chieh
Source:
Energy 2014 v.72 pp. 547-553
ISSN:
0360-5442
Subject:
air; anodes; electric power; electrochemistry; electrolytes; fuel cells; humidification; hydrogen; oxidants; polymers; temperature
Abstract:
... In this study, the performance of a polymer electrolyte membrane fuel cell stack has been evaluated for a hybrid power system test platform. To simulate vehicle acceleration, the stack was operated under dynamic-loading, and to demonstrate the exchange of power flow between two power sources the hybrid power system was tested under three different modes. A unit cell was fabricated for high stack p ...
DOI:
10.1016/j.energy.2014.05.079

19. Diagnosis and redesign of power plants using combined Pinch and Exergy Analysis

Author:
Arriola-Medellín, Alejandro; Manzanares-Papayanopoulos, Emilio; Romo-Millares, César
Source:
Energy 2014 v.72 pp. 643-651
ISSN:
0360-5442
Subject:
equipment; exergy; heat recovery; power plants; steam
Abstract:
... This paper applies the combined Pinch and Exergy Approach in analysing the operation and design of a typical steam power plant. This work quantifies the total, avoidable an unavoidable exergy loss for the equipment, which means, the potential for equipment improvement. On the other hand, the analysis of cross pinch heat transfer in the process identifies additional losses of energy due to the inef ...
DOI:
10.1016/j.energy.2014.05.090

20. Displacer gap losses in beta and gamma Stirling engines

Author:
Mabrouk, M.T.; Kheiri, A.; Feidt, M.
Source:
Energy 2014 v.72 pp. 135-144
ISSN:
0360-5442
Subject:
compressibility; geometry; heat transfer; models; momentum; temperature
Abstract:
... An analytical model has been developed to evaluate "displacer gap losses" in the clearance between the displacer and the cylinder in both β and γ configurations of Stirling engines. Displacer gap losses are the sum of the "shuttle heat transfer" and the "enthalpy pumping".The present model takes into account the pressure gradient in the gap, the gas compressibility and real gas effect. Gas velocit ...
DOI:
10.1016/j.energy.2014.05.017