Energy-saving Features Research Articles

Models and Management Structure for the Development and Implementation of Innovative Technologies in Railway Transportation. II. An Incentive Mechanism for Saving Energy and Elements of the Project Management Structure

This paper consists of two parts. In the second part, the management mechanisms for implementing complex projects that improve the energy-saving characteristics of products and technologies are further studied. An incentive model for saving energy in the sequence of projects within a multi-project structure is considered, and an optimal mechanism for this model is proposed. This mechanism includes a planning procedure, penalty functions for the nonfulfillment of plans, and an incentive function for project results. The functioning of the system is treated as a game of the Principal and sequentially connected agents who implement projects. The Principal’s strategy is the choice of a specific mechanism. The agents’ strategies are messages, in which they report to the Principal some information about their parameters, and also the choice of the project results. The information about the agents’ parameters is necessary to calculate the plans based on the planning procedure. At the same time, the agents may prefer not to tell the truth, reporting unreliable (distorted) information. It is shown that the optimal mechanism proposed below stimulates the agents to provide reliable information and also to choose the project results coinciding with the plans. The first part of this paper (see [3]) was devoted to the mechanisms of project assessment and resource allocation; the results established therein are used to propose a project management system for implementing complex projects.

Energy consumption analysis of glass house using electrochromic window in the subtropical region

PurposeElectrochromic window (ECW) has been gradually applied to building engineering in recent years. However, empirical study of this technology used in green building design is still lacking. This study aims to verify the lighting and energy-saving performance of ECW under a specific geographical environment.Design/methodology/approachThe meditation pavilion of Jinwan new materials research institute in Zhuhai is taken for research object. Three kinds of sun-shading techniques, namely, ECW, Low-E window and ordinary glass window, with same specifications are selected as the building facade structure for simulation. Day lighting analysis, sun-shading performance and annual energy consumption are separately simulated in the same environment by the Autodesk Ecotect Analysis software. The energy-saving performance of ECW is obtained by comparisons.FindingsResult shows that the shading performance of ECW is much better than ordinary window and Low-E window. When ECW is used in the east, west or top lighting interfaces of a building, about 40% of the total solar radiation can be reduced during daytime in summer. Taking the ordinary glass window as a basic reference, ECW can save about 90% of the annual energy consumption of the glass house. ECW can effectively reduce the annual refrigeration energy consumption of buildings in the subtropical region.Practical implicationsReasonable use of ECW in the subtropical region can effectively reduce the annual energy consumption of buildings.Originality/valueIt is a precedent study to analyze the lighting performance and energy consumption of a glass house with ECW. The energy-saving characteristics and beautiful appearance of ECW shall make it a future green building technology.

Plasmonic wooden flower for highly efficient solar vapor generation

Abstract Solar vapor generation has become a promising water purification technology owing to its eco-friendly and energy-saving features. However, it remains as a big challenge to further improve the solar-driven evaporation performance, especially to further increase the efficiency of solar energy utilization. Here, a novel plasmonic wooden flower is fabricated, in which Ag-polydopamine (PDA) core-shell structured nanoparticles (Ag@PDA NPs) are loaded on the wooden flower. The superior structural characteristics of the porous wooden flower and the Ag@PDA NPs provide a synergetic effect. Thus, it exhibits a high light-harvesting absorption of 98.65%. Moreover, the hydrophilic Ag@PDA NPs promote the formation of water films on both sides of the flower petal. Meanwhile, the abundant capillary channels and pinholes in the wood further enhance the heat convection and solar-driven evaporation of the water films on both sides of the petal. With the excellent thermal management performance, the plasmonic wooden flower device has a high vapor generation rate of 2.08 kg m−2 h−1 and an ultrahigh solar-to-vapor efficiency of 97.0% under 1 sun illumination, among the best values reported in the literature. It is promising for future water treatment applications in large scale including recovery of metal ions, brine desalination and sewage purification.

Research on energy-saving characteristics of battery-powered electric-hydrostatic hydraulic hybrid rail vehicles

With the advantages of no emission and low noise, battery rail vehicles (BRVs) are widely used in the construction of subway, high-speed railway and so on. However, the problems of low energy efficiency and peak power shock of traction motor have severely restricted the application and promotion of BRVs. To address these problems, an electric-hydrostatic hydraulic hybrid powertrain (EH3) is designed in this paper. Friction braking (FB) is replaced by hydraulic regenerative braking (HRB) and the mode of recovered hydraulic energy coupled at the inlet of pump (ECIP) to assist acceleration is proposed. The energy conservation characteristics of recovery and coupling of hydraulic energy in EH3 powertrain are verified by simulation and laboratory test bench. The energy recovery efficiency of HRB is up to 50% and the new coupling modes can greatly reduce the consumption of electric power. The control strategy is designed to coordinate different working modes which are established based on the high-pressure accumulator (HPA) and the driving state parameters of BRVs. The simulation result shows that the energy consumption of the battery can be reduced by 17.32%. The EH3 powertrain has broad application prospects in realizing energy conservation, reducing peak motor power shock and improving the braking performance of BRVs.

Energy-saving technologies for construction machinery: a review of electro-hydraulic pump-valve coordinated system

With the rapid development of the global economy, more and more attention has been paid to the energy conservation of construction machinery. The hydraulic system is the key component of construction machinery, and improving its energy utilization rate has become an important means to achieve energy conservation. In conventional valve-controlled or pump-controlled hydraulic systems of construction machinery, controllability and energy-saving performance typically cannot be considered at the same time. The pump-valve coordinated system combines the energy-saving characteristics of the pump-controlled system and the high-precision and high-frequency response of the valve-controlled system, which has the potential to become a primary research direction of electro-hydraulic systems. This review summarizes the recent research progress in energy-saving technologies based on pump-valve coordinated systems. Particularly, we discuss the structures of hydraulic systems in different categories of construction machinery, various control methods of the electro-hydraulic system, novel hydraulic hybrid energy regeneration systems, and key components. In addition, future directions and challenges of the pump-valve coordinated systems are described, such as independent metering system (IMS), common pressure rail (CPR), and hybrid power source (HPS).

Sampled-data containment control for double-integrator agents with dynamic leaders with nonzero inputs

The objective of containment control in multi-agent systems is to design control algorithms for the followers to converge to the convex hull spanned by the leaders. Sampled-data based containment control algorithms are suitable for the cases where the power supply and sensing capacity are limited, due to their low-cost and energy-saving features resulting from discrete sensing and interactions. In addition, sampled-data control has advantages in performance, price and generality. On the other hand, when the agents have double-integrator dynamics and the leaders are dynamic with nonzero inputs, the existing algorithms are not directly applicable in a sampled-data setting. To this end, this paper proposes a sampled-data based containment control algorithm for a group of double-integrator agents with dynamic leaders with nonzero inputs under directed communication networks. By applying the proposed control algorithm, the followers converge to the convex hull spanned by the dynamic leaders with bounded position and velocity containment control errors, and the ultimate bound of the overall containment error is proportional to the sampling period. A numerical simulation is presented to illustrate the proposed algorithm.

System Characteristics Analysis for Energy Management of Power-Split Hydraulic Hybrids

Hydraulic hybrid powertrains provide an opportunity for specific applications, such as heavy-duty vehicles based on high-power density, which has not been included in other types of hybrid powertrains. Among the various architectures of hybrid vehicles, power-split hybrids have a greater possibility of producing better fuel efficiency than other hybrid architectures. This study analyzed the possible energy-saving characteristics of power-split hydraulic hybrid vehicles (HHVs); this has not been comprehensively described in previous studies. A typical configuration of power-split HHVs was modeled with the FTP-72 driving cycle using a novel simulation method that considered the dynamic and thermal behaviors together. The characteristics were analyzed in comparison to a power-split hydrostatic transmission (HST), which is designed with the same conditions except for hydraulic energy storage. The power-split HHV not only has a better fuel efficiency, but it also shows system energy-saving characteristics. The power-split HHV has more chances for engine idling, which is directly related to fuel consumption savings due to engine stop. Additionally, more engine idling time enables the system to operate in a more efficient area on the engine map by load leveling. The results for the system temperature show that the power-split HHV offers the possibility to deliver better thermal management because it prevents the waste of braking power, which is especially crucial for hydraulic systems in comparison to other power systems such as electric or mechanical power systems. The ease of thermal management results in less energy consumption for cooling down the system temperature by minimizing the cooling system, as well as in a better thermal stability for the hydraulic system. The power-split HHV characteristics analyzed in this study can be used to design and organize the system control logic while developing power-split HHVs.

Multi-Well Pumping System Design and Field Application

Abstract In view of the low efficiency of cluster wells, a multi-well pumping system with phase-division balance is put forward based on the idea of overlapping load-dislocation vectors. In this article, the kinematics and dynamics of the system are analyzed and the torque fluctuation characteristics of the system and the changing law of the motor energy consumption are studied under theory and actual working conditions. Additionally, a comparative analysis of a computer simulation and field test is carried out from the single-well to four-well pumping system. The results show that the dynamic performance of the multi-well pumping system based on phase-division balance is obviously better than that of single-well pumping unit. In addition, the system has remarkable high-efficiency energy-saving characteristics and good dynamic characteristics with coefficient of load fluctuation approaching 1 and a markedly reduced root mean square torque. The influence of inertia force on driving moment is considered by establishing the dynamic equation of the main mechanism and doing dynamic simulation. The friction power is equivalent to the corresponding additional driving power, so the influence of friction on driving moment is considered. The computer simulation results also show that the effect of multi-wells is good. According to field test data, a four-well pumping system can save 361 kWh of electricity per day.

DECOMPRESSION SEMICONDUCTOR THERMOELECTRIC DESALINATOR WITH UV RADIATION

Objectives. The development of a decompression semiconductor thermoelectric desalinator with ultraviolet radiation.Methods. The design of a decompression semiconductor thermoelectric desalinator with ultraviolet radiation makes it possible to decrease the boiling points of seawater and the obtained fresh water and brine by changing the pressure in the desalinatior thus increasing the device’s energy efficiency.Results. The use of the designed decompression semiconductor thermoelectric desalinator with ultraviolet radiation practically reduces the boiling point of seawater, completely eliminating Joule's parasitic heat release. The Peltier thermoelectric effect of heating and cooling is completely preserved, bringing the desalinator efficiency coefficient up to almost 100% and improving its energy-saving characteristics as a whole.Conclusion. A decompression semiconductor thermoelectric desalinator with ultraviolet radiation can be used to produce fresh water and concentrated solutions from any aqueous solutions, as well as to treat wastewater from industrial enterprises with simultaneous bacterial and virus disinfection. The construction materials of the desalination device are environmentally friendly.

Energy-saving feature extraction method for urban buildings with near-zero energy-consuming based on SVR

In order to solve the problem of poor fitting performance of traditional energy saving feature extraction method in urban buildings with near zero energy consumption, an energy saving feature extraction method based on SVR is proposed. The data are recovered and processed by means of mean value substitution method, and the correlation order of data parameters is realised through grey correlation analysis. Based on the feature weighting theory, the energy saving data of near zero energy saving buildings are cluster analysed. The main component analysis method is used to deal with feature extraction data, reduce the size of feature extraction data, and use SVR to achieve the extraction of energy saving characteristics of nearly zero energy consumption buildings in cities. The experimental results show that the method is always higher than other methods, with a maximum of 88%. The results show that the method is effective in feature extraction.

Energy-saving feature extraction method for urban buildings with near-zero energy-consuming based on SVR

Energy-saving feature extraction method for urban buildings with near-zero energy-consuming based on SVR

Characterizing the Energy-Saving Behaviors, Attitudes and Awareness of University Students in Macau

Currently, energy and its usage are the primary environmental issues in all countries and regions. As a special social group, university students not only have extremely high energy consumption needs, but they have more advanced consumption concepts. Understanding their energy-saving characteristics could provide foresight for predicting the energy-saving characteristics of future residents. Using data collected from 737 valid questionnaires, from five typical universities in Macau, this study investigated university students' energy-saving behaviors, attitudes and awareness, and analyzed the possible influencing factors. The results showed that the energy-saving behaviors and attitudes of respondents from five university were nearly the same. Meanwhile, 75.98% of the respondents clearly recognized that energy-savings behaviors are closely related to their daily study and life, and 96.61% of the university students thought that it is very necessary to save energy. In addition, 92.94% of students thought it was necessary to carry out energy-saving education in universities. The regression analysis indicated that “the relationship between energy-saving awareness and daily life” and “the necessity of energy-saving education” are positively correlated with the energy-saving awareness at the significance level of 1%, whereas the energy-saving behaviors, “give priority to energy-saving products” and “shut down your computer when going out”, are positively correlated with energy-saving awareness at the significance level of 10% and 5%, respectively. Finally, we proposed effective suggestions for raising the awareness of saving energy among university students.

Performance assessment of cadmium telluride-based semi-transparent glazing for power saving in façade buildings

Façade buildings are generally highly glazed and energy-intensive especially in countries with hot weather. Power consumption in these buildings is even more significant when air conditioning (AC) is added to the figures. Building with semi-transparent photovoltaic (STPV) materials is bringing advantageous energy-saving features to these façade structures. Energy is saved by more heat being reflected resulting in less AC power consumption with the STPV thermal properties. In addition, the optical and electrical properties provide indoor sunlight with power generation. This paper investigates the net potential energy saving via applying cadmium telluride (CdTe) in Façade buildings. The analysis has been carried out using indoor and outdoor experiments considering different orientations and transparencies. Compared to a single glazing case as a reference, the application CdTe achieved a net energy saving to be as high as 20%. Furthermore, a trade-off between saving energy and environment comfort has been discussed as less transparency windows lead to more artificial light consumption. The findings indicate that STPV is a promising solution for sustainable buildings.

Energy analysis and optimization design of vehicle electro-hydraulic compound steering system

In order to reduce the vehicle steering energy consumption and improve the steering road feeling, this work proposes an electro-hydraulic compound steering (EHCS) system, which combines the functions of electric power steering (EPS) and electro-hydraulic power steering (EHPS). For this novel steering system, there is a complex mechanical-electro-hydraulic coupling relationship that affects the steering performance. Thus, how to choose the appropriate parameters to ensure the system of good energy-saving characteristics and steering road feeling is one of the key issues. The power flow of mechanical, electrical and hydraulic subsystems is used to test the coupling relationship between the parameters of the motor, hydraulic pipe, hydraulic valve, power cylinder, and mechanical steering structure, and analyze their influence on the steering energy consumption. According to the results of energy consumption sensitivity analysis, the main coupling parameters are selected as design variables, and the steering energy consumption, steering road feeling and steering wheel return error are taken as optimization objectives. To add population diversity and accelerate convergence velocity, the improved competitive multi-objective particle swarm optimization (CMOPSO) algorithm is proposed and used for optimization. The optimization results illustrate that the CMOPSO has better convergence compared with the basic MOPSO, and the EHCS system optimized by CMOPSO has a better steering economy, with better steering road feeling and smaller steering wheel return error. To verify the comprehensive steering performance, the optimized EHCS system is installed on the vehicle for an on-field road test. Compared with original EHPS, the road test results show that the energy consumption of the modified vehicle under the steering condition significantly decreases, and can also meet the steering assistance and driver road feeling requirements. Furthermore, the real road traffic scene around Nanjing University of Aeronautics and Astronautics is reconstructed to analyze the relationship between the whole vehicle energy consumption and energy characteristics of the EHCS system in the intelligent traffic environments, which verifies the steering energy consumption is reduced by 51.7% under the 15 km test road.

Trichromophore-doped cassava-based biopolymer as low-cost and eco-friendly luminous material for bio hybrid white-light-emitting diodes by dual-FRET process

White-light-emitting diodes (WLEDs) are promoted as environmentally friendly because they are energy saving-features and mercury-free aspects, but, rare-earth-free, metal-free, cost-competitive, and eco-friendly for brighter WLEDs are attractive but quite challenging in practice. This paper reports a new methodology using biopolymer luminous material in bio hybrid white-light-emitting diodes (Bio-HWLEDs) based on a trichromophore-doped cassava crystalline thick film that emits bright white light emission through a dual Fӧrster resonance energy transfer (FRET) process. The dual-FRET takes place from coumarin to sulforhodamine via the curcumin chromophore. The Bio-HWLED showed color co-ordinates (0.33, 0.32) that exactly matched with pure white light emission. The effect of temperature on luminescence and the activation energy for thermal quenching were determined using the temperature-dependent photoluminescence measurements. Moreover, Bio-HWLED showed a low luminous drop rate of 0.00069 s−1 to overcome the aggregation-induced quenching effect. These results pave the way towards the realization of commercially viable, large-scale and high-contrast bio hybrid light applications that are environmentally friendly.

Evaluation of Thermal Behavior of the Skeleton in a Green Building with the Aid of TABS

In this study, an office building in Japan that incorporates energy-saving features and environmental technologies was investigated. This office building features a green façade, natural ventilation, a concrete slab with no suspended ceilings, and thermo-active building systems. Two airconditioning systems were installed in this building—a ceiling radiation air-conditioning system and a whole floor-blow off air conditioning system. In addition, a natural ventilation system was installed. We surveyed the heat flux of the ceiling surface and indoor thermal environment of this building from 2015 through 2016. The ceiling using the heat storage amount of concrete maintains a constant temperature in the workplace during as well as after office hours. We also performed detailed measurements of the heat flux of the ceiling surface and indoor thermal environment in the summer of 2017. The results showed that the ceiling radiation air-conditioning system provided a stable thermal environment. Furthermore, we report that making use of the thermal behavior of the skeleton improved the operation of the ceiling radiation airconditioning system.

Hamiltonian-based adaptive minimum-energy tracking control for a mechatronic elevator system

The mechatronic elevator system driven by a permanent magnet synchronous motor is modeled by both the mechanical and electrical equations. The dimensionless forms are also derived for purpose of practicable movements. The novelty of this paper is that the minimum-input absolute electrical energy control (MIAEEC) and minimum control effort (MCE) based on Hamiltonian functions are derived and compared; it is found that the MIAEEC is the minimum one for the mechatronic elevator system. The proposed Hamiltonian function method provides an opportunity to find the trajectories and control input for the MIAEEC and MCE. Then, the adaptive controller is designed to track the MIAEEC’s trajectory to exhibit the robustness and energy-saving characteristics. Finally, the experimental results are successfully realized to demonstrate the adaptive tracking MIAEEC’s trajectory based on Hamiltonian function.

Numerical research on hydrodynamic characteristics of propeller boss cap fins

Objectives With the increasing popularity of the concept of green ships, marine hydrodynamic energy-saving technology has drawn more attention from researchers. This paper studies the way to reduce energy consumption of ships at sea. Methods naoe-FOAM-SJTU solver independently developed by Prof. Wan Decheng's research team in Shanghai Jiao Tong University is used to numerically investigate the hydrodynamic characteristics of Propeller Boss Cap Fins (PBCF). In order to better investigate the interaction between PBCF and propeller, the influences of PBCF on blades, hubs and hub caps are studied respectively. Results It is found that the hubs and hub caps are less affected by PBCF, and despite sharp reduction of the propeller torque, the influence of PBCF on the overall thrust is limited. Further it is found that the Reynolds number has great influence on the energy-saving characteristic of PBCF and has a critical value below which the increasing Reynolds number will give rise to greatly improved energy-saving effect, and above which, the energy-saving effect is basically unchanged. This shows that PBCF may have better energy-saving characteristics in the full scale which has the critical Reynolds number. Conclusions The findings are satisfactory and shows that the naoe-FOAM-SJTU solver is feasible for the direct simulation of hydrodynamic characteristics of PBCF, and this research method can be applied to other energy-saving devices.

Synergetic control of permanent magnet synchronous motor based on load torque observer

The control of permanent magnet synchronous motor has become an important research, and many control methods have been developed because of its high efficiency and energy-saving characteristics. This article proposes a new motor control approach based on synergetic approach in control theory (SACT) and sliding-mode control (SMC). Since the load torque of the motor will change, the moment of inertia will increase in the experiment. The load torque is estimated by the sliding-mode observer. The moment of inertia is calculated by the least squares method by adding a forgetting factor. The practical application of synergetic control theory broadens the train of thought to meet the demand of high-performance motor drive further. The simulation and experimental results show that this control scheme in this article can improve the transient response and system robustness of dynamic systems.

An Active Damping Scheme With Energy Saving Feature for Use with Regenerative Converters

Regenerative drives, also known as four-quadrant drives are an integral part of many industrial applications ranging from wind power generation, elevators, escalators, centrifuges, pump jacks in oil fields, etc. All regenerative converters need passive LCL filters to filter out pulsewidth modulation frequency components. One disadvantage of using an input LCL filter in front of regenerative converters is that they are also a major source of power loss in the power system as their configuration allows for the flow of capacitive circulating currents even when the power converter is off . The associated power loss in the power system can significantly affect the overall system efficiency when there are large numbers of large power regenerative units in the power system. The filter capacitors also interact with pre-existing voltage distortion in the power system. Multiple regenerative units of various sizes have been shown in this paper to cause undesirable voltage ripple, which in turn causes current oscillations especially in smaller sized regenerative converters. A new active damping scheme is proposed, which also includes actively opening the neutral point of the filter capacitor to eliminate standby power loss associated with regenerative converters with LCL filters. Two ideas are proposed. In the first, only one damping resistor is used, whereas in the other two, damping resistors are used in parallel, where one resistor acts as the fixed damping resistor whereas the other is modulated depending on the amount of system distortion. Test results are given to demonstrate the fundamental concept.