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Abstract In this paper, the performances of a typical R744 booster configuration, a R744 parallel-compressor booster refrigeration system, and a R717/R744 cascade system configuration are presented based on the 1st and 2nd law of thermodynamics, for food retail applications. The results for a supermarket application with a total 145 kW cooling capacity show that the typical booster system and parallel-compressor booster system have better performances than the cascade system. However, for convenience store applications with 30 kW total cooling capacity the cascade system shows better performance beyond 26 °C ambient temperature which limits the applications of the cascade system for low capacity systems and the parallel refrigeration system solution appears to be a better option. In addition, the most critical components of each system based on the 2nd law are identified in this paper. [ABSTRACT FROM AUTHOR]

Abstract Institutional structures having leader roles in sustainable development must make regular and sustainable situation analyses to improve management strategies and particularly energy resources when environmental strategies are being developed. However, in Turkey, there is not a model defined to develop in particular sustainable carbon management strategies in a holistic structure. These approaches, as a decision support component, will provide significant gains in terms of monitoring, managing and projecting of energy consumptions responsible for carbon threat in institutions. In this respect, it is necessary to develop an institutional model and to create feasible actions. However, in management inputs, it is important that the energy efficiency, the usage densities and the consumption efficiency potentials are shaped with which criteria and how. This study, which is addressed in this direction, has been shaped as a public model for enterprise structures. This work first presents a structure including an integrated carbon management system, which collecting public buildings in a single system management architecture that targets all components within their context. This model study aimed to manage the dynamic consumption processes for each building based on resource demand management. It is aimed to provide a manageable, controllable and developable infrastructure by creating a common language for the terminals of the energy systems having different languages and structures, which is the main source of carbon emissions. Early results from preliminary studies in some schools point to savings of over 20% in consumption. [ABSTRACT FROM AUTHOR]

Abstract Refrigerated containers account for half of the total electricity consumption by storage yards and that this is expected to increase continuously each year. A refrigerated container is a special cargo container equipped with an integral refrigeration unit. The amount of power consumption of the refrigerated container will change depending on many external variables. Environmental factors mainly solar radiation received on the container walls caused surface temperatures increase will then affect the power consumption. This paper provides a simulation study on the estimation of energy consumption of refrigerated container. The simulation model performed on the building-design energy analysis used Integrated Environmental Solution (IES) software packages. The geometry of simulation model considers the actual dimension of refrigerated container consists of insulation walls in the three-dimensional analysis. Physical properties of the insulation walls and environmental factors used weather data are applied to the simulation model as parameter inputs. Estimation of energy consumption of the model based on the calculation of cooling load from the object considers the thermal effect from the sun energy. The measurement data from the experimentation was conducted by Shinoda and Budiyanto (2016) used as validation of simulation model. The comparison of energy consumption from simulation and measurement shows in shows in good agreement. [ABSTRACT FROM AUTHOR]

Abstract Hybrid vehicles are one of the most important choices to improve efficiency and reduce CO2 production of vehicles. Benefits in using hybrid powertrains are generally found in urban environment where lower average speeds, higher accelerations make the internal combustion engine run at lower efficiency points. The originality of the present paper consists in the data elaboration and analysis collected in a measurement campaign on road in real driving conditions, on an ad hoc path planned according to the average national daily mileage in metropolitan urban context, which thus acquires a significance generalizable in that specific context, which led to the consumption quantification and an analysis of the main factors that determine the reduction in consumption of full-hybrid vs conventional vehicles. Another important and original aspect of this paper is the analysis of the operating times in ZEV mode of hybrid vehicles, which shows how this solution leads to a significant reduction of pollutant emissions in urban contest. An on-road experimental campaign has been done by comparing two different versions of the same model (Toyota Yaris Hybrid and a conventional one, Toyota Yaris 1.5 gasoline) and a hybrid vehicle with different characteristics (the hybrid born - Toyota Prius), like size, traction battery capacity, generator/motor electric power. Thirty drivers on a fixed path have done this experimental campaign and in this paper, the results are reported. The results show that a strong influence on consumption is due not only to the type of vehicle, but also to driving style and speed. The comparison between the two versions of Yaris, shows a strong reduction in consumption using hybrid vehicle for low and medium speeds (for 20 km/h about 50%), such benefit decreases with the increasing speed and for values higher than 90 km/h both the vehicles have the same consumption. The reduced consumption of the hybrid vehicle at low speeds is due, on the one hand, to the greater efficiency of the hybrid vehicle engine compared to the conventional one and on the other hand to the high functioning in ZEV mode, with the engine off, (63% of time) thanks to the use of the electric motor. The comparison between the two hybrid vehicles with different characteristics (YarisHy and Prius) shows that the consumption trend vs. speeds is similar but the Prius has lower consumption due above all to the high efficiency of the braking energy recovery system, despite the greatest mass. This lead then to significant consumption reduction, but also lower emissions in places where such parameters have an important role: the urban environment. [ABSTRACT FROM AUTHOR]

Different with traditional aboveground data centres, underground data centres have attracted increasing attention during recent years due to its inherent geographical advantages such as zero solar heat gain, low ambient temperature, natural geothermal cooling, and solid rock surrounded structures. The energy reduction in air-conditioning and mechanical ventilation (ACMV) system of the underground data centre is even more significant for the tropical regions where air is hot and humid all the year round. However, little study has been conducted to systematically analyse the relationship between the air-conditioning effectiveness and the corresponding energy efficiency. In this work, both energy simulations and computational fluid dynamics (CFD) simulations are conducted to the underground air-conditioning data centres in the tropics. The former one studies the energy consumption and energy efficiency of the whole ACMV system for a data centre. Meanwhile, the latter one studies the corresponding detailed airflow pattern within the data centre room. Optimizations in air management of the ACMV system are also proposed based on the energy and CFD simulation results. [ABSTRACT FROM AUTHOR]

By relating to both the quality and quantity of energy flows, exergy analysis can be used to assess the improvement potential of thermodynamic systems. Exergy analysis has previously been applied at the economy level in order to provide a measure of the scope for efficiency improvement. While this approach can help to guide progress, meaningful analysis that takes full advantage of the insights of exergy, at this scale, retains some challenges. This study explores three relevant considerations to the interpretation and use of exergetic improvement potential applied at the macro (economy) scale. Specifically: (i) the nature of the relationship between improvement potential and the changes in efficiency that occur, (ii) the relative significance of exergy embodied in flows and (iii) the sensitivity of efficiency calculations to the definition of systems outputs. The nature of these considerations is evaluated empirically, using historic data. It is shown that exergy can provide useful information but that there is a complementary role for energy analysis. The scope for savings outside of direct “improvement potential” is also noted. It is hoped that appreciation of these considerations will lead to more effective exergy analysis at the economy scale, with its advantages and also limitations properly understood. [ABSTRACT FROM AUTHOR]

In this paper, a steam Rankine cycle is proposed for the subsea power supply. The turbine, as the key component, is connected to a power shaft to produce the power output. The pressure at the inner and outside of the turbine shaft seal can be balanced. A mathematical model is established, energy and parametric analysis are applied. The results show that this power cycle can acquire a thermal efficiency of 35% at 5000 meters depth. Besides, the electrical heating temperature and the condensing pressure are the key parameters that dominant the performance of this cycle. [ABSTRACT FROM AUTHOR]

We present herein a techno-economic feasibility for implementation of nitrogen-based fuels. Firstly, we compared the nitrogen- and carbon-based routes for chemical hydrogen storage. The above hydrogen carrier routes were evaluated on an energy basis, under defined system boundaries by comparing seven alternative fuels. Ammonia was found to be the best energy vector, followed by methane, methanol, and aqueous ammonium-hydroxide urea. Secondly, we evaluated the economic feasibility of a model nitrogen-based fuel by using levelized cost of storage analysis. The results indicated that a nitrogen-based fuel is competitive with other storage technologies under development. Furthermore, a decrease in the hydrogen cost can lead nitrogen-based fuels to be competitive with currently-used mature technologies. Thirdly, the utilization of the nitrogen-based fuel route was demonstrated. The auto-ignition process of a model fuel, aqueous urea ammonium nitrate (UAN) was described. The results indicate that this fuel is safe to use, store and handle under ambient pressure. We studies potential storage and reaction vessel materials, pointing out favorable metal alloys for these purposes. In addition, a catalyst screening study aimed at pollution reduction during batch combustion of this fuel is reported, as are preliminary results for continuous catalytic combustion. This work demonstrates the feasibility of catalytic pollution abatement for UAN combustion and the clean utilization of this fuel. [ABSTRACT FROM AUTHOR]

In heavy duty Diesel engines more than 50% of the fuel energy is not converted to brake power, but is lost as heat. One promising way to recapture a portion of this heat and convert it to power is by using thermodynamic power cycles. Using the heavy duty Diesel engine as the waste heat source, this paper evaluates and compares the thermodynamic potential of different working fluids in four power cycles: the Rankine cycle (RC), the transcritical Rankine cycle (TRC), the trilateral flash cycle (TFC) and the single flash cycle (SFC). To establish the heat input into the cycle, operating conditions from an actual heavy duty Diesel engine are used as boundary conditions for the cycle heat source. A GT-Power model of the engine was previously developed and experimentally validated for the stationary points in the European Stationary Cycle (ESC). An energy analysis of this engine revealed that it has four heat sources with the potential for waste heat recovery: the charge air cooler (CAC), the coolant flow, the exhaust gas recirculation cooler (EGRC), and the exhaust flow. Using fixed heat input conditions determined by the selected engine operating mode, the TFC performed best for the CAC with a net power increase of around 2 kW, while the RC performed best for the coolant flow, with a net power increase of 5 kW. For the EGRC, ethanol performed especially well with both the RC and TRC, leading to an 8 kW net power increase. When using the exhaust as heat source, all four cycles provided a power output of around 5 kW with some variation depending on the working fluid. This study shows that for most cases, considering the different heat sources, the choice of cycle has a larger impact on the cycle performance than the choice of working fluid. [ABSTRACT FROM AUTHOR]

This work addresses the techno-economic assessment of two chemical looping technologies for H 2 production from natural gas fully integrated with CO 2 capture. In the first configuration, chemical looping combustion operated with a dual circulating fluidized bed system at atmospheric pressure is used as furnace for the reforming reaction. In the second configuration, a chemical looping reforming system at pressurized conditions is used for the production of the reformed syngas. Both configurations have been designed and compared with reference technologies for H 2 production based on conventional fired tubular reforming with and without CO 2 capture. The results of the analysis show that both new concepts can achieve higher H 2 reforming efficiency than a conventional plant when integrated with CO 2 capture (+8-10% higher). The improvement in the performance of the plant is accompanied with an efficiency penalty of 4-6% and the cost of CO 2 avoidance varies from 20-85 €/ton CO2 . [ABSTRACT FROM AUTHOR]

Combined heat and power (CHP) systems fed by renewable sources are of great interest for efficient and greener energy production in industrial applications. In order to reduce fossil fuel consumption, biomass gasification coupled with I.C.E. is a viable way for ensure constant and accurately predictable renewable energy production. The aim of this work is to evaluate the integration in an industrial context of a CHP system fed by syngas produced from woody biomass gasification in a downdraft reactor. The feasibility study was developed thorough the combination of two simulation programs. Aspen Plus was used for simulating the biomass gasification unit and was exploited in order to determine the syngas composition and flow rate. Results have been employed in TRNSYS, that has instead been chosen for the modeling of the complete CHP system. [ABSTRACT FROM AUTHOR]

This paper presents an emergy analysis in biomass cogeneration. Emergy analysis have been made for the power plant which is located in Latvia. The aim of emergy analysis is to evaluate the amount of solar emergy used in energy production. Emergy is the availability of energy (exergy) that is consumed in direct and indirect transformations required to make a product or service. The unit of emergy is solar emjoule (seJ). To calculate emergy, transformity is used to express energy units in to solar emjoules. To express other units into emergy, specific emergy, emergy per unit money, emergy per unit labor is used. Empower is defined as flow of emergy. A part of emergy analysis is the system diagram. The system diagram helps to show main inputs, outputs, components and flows between them. The system diagram of cogeneration plant is shown in figure. Several inputs as renewable, non-renewable, labour and economical have been taken in account in emergy analysis. System diagram shows main flows between inputs and components of the system. All inputs and outputs are converted in emjoules. Finally, emergy indicators such as renewable fraction, emergy yield ratio, emergy sustainability index, etc. are calculated. [ABSTRACT FROM AUTHOR]

The paper presents use of energy and exergy analyses for the assessment of input and output flows in a cogeneration plant, shows points of exergy degradation in a system and allows to make a quantitative evaluation of energy quality changes. The objective of the study is to determine the essential points and values of exergy destruction in a biomass combined heat and power (CHP) plant in Jelgava, as well as to define boundaries of the method's use. A mathematical model is elaborated, used and evaluated as suitable for its application for the real plant and may be used in the plant's further operation for efficiency assessment and improvements. The results are shown with Sankey and Grassmann diagrams; the largest exergy destruction occurs in the boiler (steam generator) and represents 63.7% of input fuel exergy; second largest exergy destruction is observed in heat exchangers of district heating (DH) system. Exergy efficiency of the plant is influenced by the power to heat ratio (α) and potential of the produced heat (temperature). Increased heat load or decreased temperature of heat delivered to the consumer lowers the value of exergy efficiency of the plant. [ABSTRACT FROM AUTHOR]

In the present study, a novel solar thermal roof collector was developed by primarily exploiting components and techniques widely available on the market and coupled with a commercial heat pump unit. The proposed indirect series solar-assisted heat pump system was experimentally tested and preliminary system performance was investigated. Yet, the analysis based on indoor and outdoor testing predominantly focuses on the solar thermal roof collector. A detailed thermal model was developed to describe the system operation. Also, a computer model was set-up by using Engineering Equation Solver (EES) to carry out the numerical computations of the governing equations. Preliminary analyses show that the difference in water temperature could reach up to 18 °C while maximum thermal efficiency found to be 26%. Data processing of the series covering the test period represents that Coefficient Performance of the heat pump (COP HP ) and overall system (COP SYS ) averages were attained as COP HP =3.01 and COP SYS =2.29, respectively. [ABSTRACT FROM AUTHOR]

Recent developments in computational design tools have bridged a gap between a well-established parametric building modeling [1] and analysis or simulation software such as EnergyPlus [2] , Radiance [3] , Daysim [4] and OpenStudio [5] , opening up the possibility for architects to use the computational power to model and simulate real environmental behavior of the architectural artefact and its components. Now architects are able to evaluate the behavior of a project, whether it is a building, a city, a landscape or infrastructure and a new road towards an architecture based on performance is opened [6] . Therefore we can put the idea of performance as a precedent to shape development and the architectural form becomes informed by the performative aspects. We can use various computational tools in order to gather qualitative and quantitative aspects of the architectural artefacts performance in the early stages of design, and we can go further from just optimizing a form after it has been defined. This paper will discuss the implications of parametric modeling and energy analysis in architectural design and will present the authors research in developing architectural forms using the above described tools. [ABSTRACT FROM AUTHOR]

An energy balancing system (EBS) performs heating and cooling by utilizing the refrigerant cycle. As it produces heating and cooling simultaneously, EBS has an advantage when heating and cooling demand occur simultaneously. Furthermore, with increase in a thermal storage capacity, it can conduct energy balancing by heating and cooling which occur at different times. It can result in both an increase in the heating and cooling produced by energy balancing and a reduction in operating cost. However, it leads to increase the initial cost of the thermal storage tank. This study suggests that total cost should be considered adapting EBS. [ABSTRACT FROM AUTHOR]

The objective of this paper is to present the study of the optimal synthesis of energy efficient distillation columns (EEDCs) sequence of aromatics separation process by using driving force method. In order to perform the study and analysis, the EEDCs sequence methodology is developed. Accordingly, the methodology consists of four hierarchical steps; Step 1: Existing Sequence Energy Analysis, Step 2: Optimal Sequence Determination, Step 3: Optimal Sequence Energy Analysis, and Step 4: Energy Comparison. The capability of this methodology is tested in designing minimum energy distillation column sequence for aromatics separation process. The results show that the maximum of 7.0% energy reduction was able to achieve by changing the sequence suggested by the driving force method. It can be concluded that, the sequence determined by the driving force method is able to reduce energy used for aromatics separation process in an easy, practical and systematic manner. [ABSTRACT FROM AUTHOR]

The objective of this paper is to present the study of the optimal synthesis of energy efficient distillation columns (EEDCs) sequence of hydrocarbon mixture separation process by using driving force method. In order to perform the study and analysis, the EEDCs sequence methodology is developed. Accordingly, the methodology consists of four hierarchical steps; Step 1: Existing Sequence Energy Analysis, Step 2: Optimal Sequence Determination, Step 3: Optimal Sequence Energy Analysis, and Step 4: Energy Comparison. The capability of this methodology is tested in designing minimum energy distillation column sequence for hydrocarbon mixture separation process. The results show that the maximum of 18% energy reduction was able to achieve by changing the sequence suggested by the driving force method. It can be concluded that, the sequence determined by the driving force method is able to reduce energy used for hydrocarbon mixture separation process in an easy, practical and systematic manner. [ABSTRACT FROM AUTHOR]

Due to the rapid increase in price of resources, the role of energy management and utilisation has become significant in processing industry. Industries can be more competitive by increasing the energy efficiency and eliminating waste. In this research, an old-style paper plant situated in China has been selected for the case study. The purpose of the study is to test whether the energy usage is reasonable and to exploit the potential of waste as a resource for its production process. To do so, a huge data of the paper plant are obtained, and then based on these figures, a model has been established to find out the potential wastes and thermal energy loss of the process. The simulation results revealed that the mill's energy use is quite reasonable, however, findings found that there are still further possibility for organic waste to be reused. [ABSTRACT FROM AUTHOR]

Due to the rapid increase in price of resources, the role of energy management and utilisation has become significant in processing industry. Industries can be more competitive by increasing the energy efficiency and eliminating waste. In this research, an old-style paper plant situated in China has been selected for the case study. The purpose of the study is to test whether the energy usage is reasonable and to exploit the potential of waste as a resource for its production process. To do so, a huge data of the paper plant are obtained, and then based on these figures, a model has been established to find out the potential wastes and thermal energy loss of the process. The simulation results revealed that the mill's energy use is quite reasonable, however, findings found that there are still further possibility for organic waste to be reused. [ABSTRACT FROM AUTHOR]

Typically, PV water pumping (PVWP) systems for irrigation are normally designed based on the worst conditions, such as high water demand and low solar irradiation. Therefore, the installed PVWP systems become oversized in most of time. Since the conventional control systems don’t optimize the water supply, the water losses are increased. To remedy the problems related to the operation of the oversized systems, a novel control system is proposed. The control unit interacts between water demand and water supply in order to pump only the amount required by crops. Moreover, the novel control system substitutes the conventional protection approach with a method based on the ground water resources availability and response. The novel control system represents an innovative solution for water savings in PV watering applications. [ABSTRACT FROM AUTHOR]

Improved understanding of ship energy use can be a crucial part of the process of increasing ship energy efficiency. In this paper, the methodology of energy analysis is applied to ship energy systems in order to showcase the benefits of such methodology. Data from one year of operations of a case study ship were used, together with mechanistic knowledge of ship systems, in order to evaluate the different energy flows. The identification of main producers, consumers and waste flows, allowed by the application of the method, leads to the suggestion of a number of possible improvements guided by the improved knowledge of the ship's energy system. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents the simulation activity carried out to analyze the power flows and the energy breakdown of an innovative hybrid-turbocompound powertrain, which will be employed in the 2014 F1 championship. The analyzed powertrain consists in a supercharged internal combustion engine integrated by two electric machines – connected respectively to the turbocharger shaft and to the engine shaft – a static converter and a battery. Simulations through Matlab-Simulink were carried out both in race and in qualifying conditions, obtaining useful information about the electric machines and battery duty cycles and about the calibration of the system operational algorithms during one lap. [Copyright &y& Elsevier]

Abstract: Nowadays many people use public transports in urban centers. Consequently, every day a lot of buses move within cities, trying to ensure the best service to citizens. During the year buses become crowded places and using an air conditioning system in constant operation, it tries to ensure a certain condition of comfort for the passengers on board. The aim of this study is to analyze and optimize the energy performance of a bus shell, identifying practical solutions have not yet been adopted in order to reduce the impact of air conditioning on bus’ consumption and, therefore, on air pollution. For this reason it was decided to conduct a thermal analysis of a bus for public transport, in order to understand the behavior of the bus shell and to deduce possible optimization measures that have not yet been made until now. The analysis was carried out considering the hottest day of July and the coldest day of January, considering the operating conditions based on the most common graphics TGM (Average Daily Traffic) able to define the concentration of traffic city during the 24hours per day. The study was done using the dynamic simulation software TRNSYS. With this software it was possible to recreate faithfully the structure of the bus and the external environmental conditions, assessing the impact of different technical solutions for an improvement of internal conditions and a reduction of the cooling capacity required. As the presence of passengers on public transport are considered like a “benefit” during the winter, the analysis is started with the identification of a summer solution and the subsequent evaluation of this solution for the winter time. The aim of this study was to optimize the bus shell and select the most appropriate solutions. Regarding the transparent surfaces it has been given importance to factors such as the thermal transmittance and the solar gain factor (g-value). Aware of the influence given by the solar radiation on the energy loads, bus energy performance were simulated also considering different types of paintwork with high reflectance. [Copyright &y& Elsevier]

Abstract: Renewable energy in food industry and particularly in drying process is growing and mainly in developing countries. Solar energy is often used by direct products exposure through a glass or to heat drying air through a solar collector. However, the random and intermittent nature of solar radiation leads to use conventional energy sources as supplement. Hence, optimization and design tend to reduce the drying time of products for minimum possible energy use. These cases are often preceded by rigorous energy and exergy drying process analysis. That is the aim of our work in this paper. The used dryer is an indirect type, passive, without extra energy and discontinuously operating. It is composed of a solar air heater and a drying room. The experiment took place at Bouzareah on the heights of Algiers in the summer season. The choice of mint is because its abundance and its wide use in Algeria. Using the first and second principles of thermodynamics, we could estimate useful energy received by the heater and that really used during drying. Energy analysis has allowed us to quantify the solar energy received by solar heater and available for drying. Exergy analysis has allowed us to estimate the energy losses during the drying process. [Copyright &y& Elsevier]