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Abstract: There is a large value in making Pulp and Paper mills more energy efficient. ABB has developed an energy assessment service where opportunities to save energy in the paper machine are identified. The energy assessment is done by quantifying energy flows, benchmarking energy users, data mining and steam sensitivity analysis and by experiments and additional measurements at the paper machine. Energy quantification helped in identifying main energy consumer, benchmarking was useful to assess the gap between operating performance and best performance whereas data mining and steam sensitivity analysis helped in studying the impact of key operating variables on performance of paper machines. After the assessment an action plan was presented to the mill for energy efficiency improvement together with a return on investment. [Copyright &y& Elsevier]

Abstract: Urban neighborhoods could represent an optimal scale for the implementation of innovative energy strategies. However, barriers at the economic, regulatory and administrative level are still present. In this framework, it is important to operate on three levels of the energy system: by reducing energy demand; by optimizing generation and management system, and by integrating local renewable energy sources. In recent years, as a result of an important agreement with the Italian Ministry of Environment, Lombardy Region has supported numerous measures for energy efficiency and renewable resources integration among its territory. The funding supported different actions such as improvements of the buildings envelope, substitution of old gas boilers for heat generation with more efficient components, integration of solar thermal systems in buildings, hydrogen and more sustainable mobility, and district heating plants, which present contribution concerns. About district heating the incentives were provided within two different calls: one aimed at the creation of plants and district heating networks and another for the extension of existing systems. Main aim of the research is to evaluate effects, effectiveness, pros and cons of the several calls for funding; to that end a methodology was developed in order to collect the data and elaborate representative energy, environmental and economic indicators. The most important characteristics, conditions and technical features of the considered plants are described in the present paper trying to provide information on the effectiveness of the supporting measures taken in order to orient future choices and to identify the most promising strategies and technologies for improving energy and environmental performances of communities. In particular present paper is related to 10 district heating plants: 6 are based on biomass and located in mountain areas, 3 are based on natural gas and located in urban areas, while the last is connected to the urban waste to energy plant. One of the important lesson is learned is that district heating (fuelled by biomass, fossil, waste and CHP or not) represents an innovative field of knowledge far from standard: in general each plant has to be evaluated on the basis of specify characteristics and it is very hard to find out average performances from the environmental and economic point of view. The results obtained during the monitoring campaign could help in providing information on the effectiveness of the supporting measures adopted and also to orient future choices by Lombardy Region and, in particular, to identify the most promising technologies for improving energy and environmental performances of communities and to develop a model for the optimization of energy use in the built environment. [Copyright &y& Elsevier]

Abstract: In this paper, the ways of employing energy storage devices in hybrid powered orthoses have been discussed. Since these devices have many unrivalled advantages, they are environmentally safe, they store kinetic energy as potential energy and release it when it is needed and they do not need external power supply. In this paper an energy storage device (linear extension spring) has been implemented in FES-cycling, the efficiency has been calculated for different spring positions and different spring constants. It was clear that FES-cycling efficiency increases when the spring constant increases, then the pedal, spring and the overall powers were calculated, and it appears that by leaning the spring position the overall power will be always positive, and the spring absorbs the exceeded pedal energy and releases it when the pedal power is negative. This study highlights the importance of using energy storage devices to improve FES-cycling performance, which has been proven that such improvement is highly related to the mechanical design of the bicycle. [Copyright &y& Elsevier]

Abstract: Prefect fore-separation technology is the precondition and key to realize garbage synthesis treatment and increase resource utilization ratio. To the lower purity quotient and efficiency of plastic and paper separation, main factors influencing performance of horizontal flow separation are analyzed in detail, and reasonable processing and design parameter are studyed in this paper. Horizontal flow separator of urban garbage that structure is reasonable and parameter can be adjusted is designed. Technology reference and support is provided to production of urban garbage treatment factory. [Copyright &y& Elsevier]

Abstract: This paper introduces the overview of China''s solar water heater industry. The share of non-pressurized compact SWHs is about 80%. Due to its low pressure-resistant, the thermal performance testing for non-pressurized SWHs is not as easy as the pressurized system. The pressure for the supplied water for the testing must be lower enough to ensure the tested SWH cannot be damaged. So, except the method identified in ISO 9459-2, China national standard introduces another way to test the thermal performance for the non-pressurized SWHs. It uses a pump to mix the water in the non- pressurized water tank, records the temperature at the beginning and the end of the test, and calculates the heat gain under the daily irradiation. This test method is much closer to the real using situation for these SWHs. In 2012, China will issue a new national standard for solar water heaters Minimum allowable values of energy efficiency and energy efficiency grades for domestic solar water heating systems. This standard requires all products sold in China should be labeled with the energy efficiency grade. The energy efficiency grade is calculated with the value obtained by the thermal performance test. A complicated test system like a testing laboratory is not suitable for the factories in China. A compact automatic test facility to assist the factory to determine its products’ energy efficiency grade is needed. This test facility has user-friendly interface developed with LabView, can perform the test and print the test report automatically. [Copyright &y& Elsevier]

Abstract: This paper presents a study of the effect of key design parameters on energy performance of two-storey single family dwellings and small scale neighborhoods, in a mid-latitude northern climate. Design parameters include the geometric shapes of dwelling units and their assemblage in a neighborhood. The effects of the design parameters are presented in a matrix that relates design parameters to performance criteria. An example for an evaluation system of the performance of design alternatives is proposed, based on design parameter effects and weights assigned to different performance criteria. Performance criteria considered are heating and cooling energy consumptions, solar energy generation, and shift of peak of electricity generation. The evaluation system is a decision-aiding tool, which enables selection of design parameter values leading to optimal performance for the assumed performance criteria. A design methodology is proposed for the design of solar optimized housing units and neighborhoods, based on the matrix of results and the evaluation system. [Copyright &y& Elsevier]

Abstract: In this paper the comparison between the performance of a cross flow heat exchanger in wet and dry operation for air handling process has been investigated. In addition, a case study of application of the component to perform indirect evaporative cooling in a AHU was studied with the software TRNSYS.Using experimental data and an appropriate analytical method, energy saving performances of the system has been evaluated through the entire cooling season for a typical Mediterranean site. Results show that high energy saving potential can be obtained if the component is operated in wet operation in term of reduction of electricity consumption. [Copyright &y& Elsevier]

Abstract: Energy efficient HVAC solutions may be obtained by combining different energy sources – fossil and renewable – into single hybrid systems. This leads to a variety of system concepts with specific boundary conditions. As a consequence, the definition of a unique representation method and a standardized performance evaluation procedure is a challenging task. Currently, two international projects promoted by the IEA are dealing with the representation and the performance calculation of a particular category of hybrid systems, i.e. integrated solar assisted systems. The HPP Annex 34 “Thermally Driven Heat Pumps for Heating and Cooling”, whose goal is to reduce the environmental impact of heating and cooling by the use of thermally driven heat pumps, has solar cooling as one of the systems under investigation. The joint project between SHC and HPP Task 44/Annex 38 “Solar and Heat Pump Systems” is focused on different system combinations of solar thermal collectors and heat pumps. The scope of the present paper is to show a systematic methodology to represent and evaluate the energy performance of complex hybrid systems. The proposed approach is a joint effort of the on-going IEA activities and will be discussed regarding the mentioned solar hybrid systems. However, the final goal of the work is to provide a basis for a simple, fair and transparent comparison of all systems for heating and cooling, regardless of the technology. [Copyright &y& Elsevier]

Abstract: Benchmark refrigerated systems in the road transportation sector are powered by diesel, having operation costs of up to 6,000 €/y. This paper presents the development of an alternative refrigeration system based on fuel cells, with higher efficiency, reduced costs and independent of diesel price fluctuations. Energy load profiles have been analyzed and the fuel cell stack and auxiliaries are being modeled in order to dimension and design a balance of plant and control algorithms that ensure a safe and easy utilization. Additionally, a prototype shall be tested under different load profiles to validate the control strategies and to characterize the performance of the system. [Copyright &y& Elsevier]

Abstract: In order to improve the photoelectric efficiency and solar energy utilization of PV module, a set of photovoltaicdouble resource heat pump (PV-DHP) is designed in this paper. Through calculation of system performance, the result shows that the efficiency of PV-DHP system can be up to 4.86 and photoelectric efficiency increases highly. According to economic compare, it is known that the operation cost of PV-DHP is 61.6% of air source heat pump, 16.6% of oil-fired boiler and 19.5% of electric heater. [Copyright &y& Elsevier]

Abstract: In this paper, a practical method to design a robust controller for pressure of boiler in Mashhad Power plant using H∞ is proposed. To achieve a good performance of an industrial boiler in order to reduce fuel consumption rate and reaching higher efficiency, dynamic variables such as fuel flow, air flow and pressure of boiler must be controlled. However this dynamic model may associate with uncertainties. Uncertainties in mentioned model are caused by lack of knowledge about the dynamics of the system, pay load changes, and air flow. Thus, application of robust control methods for high precise control of pressure is inevitable. In the first step plant is identified by using experimental data by the mean of converting into a group of linear time invariant (LTI) uncertain plants. After representation of the uncertain dynamic system in general control configuration and modelling the parametric uncertainties, nominal performance, robust stability and robust performance against disturbances are analyzed by the concept of structured singular value μ. Then, using genetic algorithm an optimal controller is designed for tracking problem and disturbance rejection. This procedure gives a satisfactory controller at the presence of model perturbations. For more comparisons, quantitative feedback theory (QFT) as a well known robust control approach is also applied to the plant. Finally, nonlinear simulation has been carried out and two controllers are compared. Both optimal robust controllers guarantee robust performance of the system against the uncertainties and result in desired time responses of the output variables. By applying H∞ robust control, system tracks the desire reference inputs in a less time and with smoother time responses. [Copyright &y& Elsevier]

Abstract: A computational study to assess the performance of different gas turbine plants is presented in this paper. The work includes the effect of relative humidity, ambient inlet air temperature and types of fuels on gas turbine plants. Investigation also covers economic analysis and effect of fuels on emissions. Gas turbine frames of various ratings are used in gas turbine power plants in Saudi Arabia. 70 MWe GE-6101FA and 40 MWe GE-6561B frames are selected for the present study. GT PRO software has been used for carrying out the analysis including; net plant output and net efficiency, break even electricity price, break even fuel LHV price, carbon emissions etc., for a given location of Saudi Arabia. The relative humidity and ambient inlet air temperature have been varied from 30 to 45% and from 80 to 100° F, respectively. Fuels considered are natural gas, diesel and heavy bunker oil. Simulated gas turbine plant output from GT PRO has been validated against an existing gas turbine plant output. It has been observed the simulated plant output is less than the existing gas turbine plant output by 5%. Results show that variation of relative humidity does not affect the gas turbine performance appreciably for all types of fuels. For 70 MWe frame, for a decrease of ambient inlet air temperature by 10°F, plant net output and efficiency have been found to increase by about 5 and 2%, respectively for all fuels. More specifically, plant net output and efficiency for natural gas are higher as compare to other fuels. For given 70 and 40 MWe frames, break even fuel price and electricity price have been found to vary from 2.03 to 2.54 US$/MMBTU and from 0.021 to 0.0254 US$/kWh respectively. It has been noticed that turbines operating on natural gas emit less carbon relatively as compared to other fuels. [Copyright &y& Elsevier]

Abstract: Nowadays, distributed generations (DGs) have taken a special role in power systems. Distributed generations have received significant attention as a means to improve the performance of the electrical power system, provide low cost energy, and increase overall energy efficiency. A problem with such generators is the unwanted islanding phenomenon. Islanding detection an important and challenging issue to power engineers. Several methods based on passive and active detection scheme have been proposed in the literature. While passive schemes have a large non detection zone (_DZ), concern has been raised on active method due to its degrading power quality effect. In this paper, a new technique to detect islanding conditions has been proposed for micro turbine (MT) as distributed generation. The performance of the proposed method based on passive methods is much more appropriate than that of previous methods. The simulation results performed in Simulink-MATLAB, clearly show improved operation of this method. [Copyright &y& Elsevier]