Sludge,the massive by-product of the sewage system,became a major challenge for the wastewater treatment industry.Yet,conventional methods often face challenges like low efficiency,high energy consumption,and environm...Sludge,the massive by-product of the sewage system,became a major challenge for the wastewater treatment industry.Yet,conventional methods often face challenges like low efficiency,high energy consumption,and environmental pollution.Especially,the improper treatment and disposal of toxic sludge generated from different industrial processes or specific wastewater treatment operations exerted significant pressure and threat to hydrosphere,pedosphere,atmosphere and even biosphere.展开更多
This paper presents a new quasi-static single-phase energy recovery logic （QSSERL）, which unlike any other existing adiabatic logic family,uses a single sinusoidal supply-clock without additional timing control volt...This paper presents a new quasi-static single-phase energy recovery logic （QSSERL）, which unlike any other existing adiabatic logic family,uses a single sinusoidal supply-clock without additional timing control volta- ges. This not only ensures lower energy dissipation, but also simplifies the clock design, which would be otherwise more complicated due to the signal synchronization requirement. It is demonstrated that QSSERL circuits operate as fast as conventional two-phase energy recovery logic counterparts. Simulation with an 8bit logarithmic look- ahead adder （LLA） using static CMOS,clocked CMOS adiabatic logic （CAL,an existing typical single-phase ener- gy recovery logic）,and QSSERL,under 128 randomly generated input vectors,shows that the power consumption of the QSSERL adder is only 45% of that of the conventional static CMOS counterpart at 10MHz, and the QS- SERL adder achieves better energy efficiency than CAL when the input frequency finput is larger than 2MHz.展开更多
Energy recovery device （ERD） is an important part of the seawater reverse osmosis （SWRO） desalination system. There are principally two kinds of ERDs, the centrifugal type and the positive displacement （PD） type...Energy recovery device （ERD） is an important part of the seawater reverse osmosis （SWRO） desalination system. There are principally two kinds of ERDs, the centrifugal type and the positive displacement （PD） type. The PD type is of extensive concern and is preferred in large-scale plants. In this article, an innovative fluid switcher was presented and a two-cylinder hydraulic energy recovery unit with a lab-scale fluid switcher was set up. Tap water was used as the working medium instead of the actual seawater and brine in SWRO desalination plants. Under steady state operating conditions, the experimental results were obtained on the variations of the pressure and flow rate to and from the energy recovery unit. The hydraulic recovery efficiency （En） of the energy recovery unit with the fluid switcher reached up to 76.83%.展开更多
The purpose of this paper is to develop an implementable strategy of brake energy recovery for a parallel hydraulic hybrid bus. Based on brake process analysis, a dynamic programming algorithm of brake energy recovery...The purpose of this paper is to develop an implementable strategy of brake energy recovery for a parallel hydraulic hybrid bus. Based on brake process analysis, a dynamic programming algorithm of brake energy recovery is established. And then an implementable strategy of brake energy recovery is proposed by the constraint variable trajectories analysis of the dynamic programming algorithm in the typical urban bus cycle. The simulation results indicate the brake energy recovery efficiency of the accumulator can reach 60% in the dynamic programming algorithm. And the hydraulic hybrid system can output braking torque as much as possible.Moreover, the accumulator has almost equal efficiency of brake energy recovery between the implementable strategy and the dynamic programming algorithm. Therefore, the implementable strategy is very effective in improving the efficiency of brake energy recovery.The road tests show the fuel economy of the hydraulic hybrid bus improves by 22.6% compared with the conventional bus.展开更多
A lab-scale expanded granular sludge bed （EGSB） reactor was employed to evaluate the feasibility of the hydrogen energy recovery potential from high strength organic wastewater. The results showed that a maximum hyd...A lab-scale expanded granular sludge bed （EGSB） reactor was employed to evaluate the feasibility of the hydrogen energy recovery potential from high strength organic wastewater. The results showed that a maximum hydrogen production rate of 7.43 m^3 H2/m^3 reactor · d and an average hydrogen production rate of 6.44- ms H^2/ms reactor · d were achieved with the hydrogen content of 50% -56% in the biogas during the 90-day operation. At the acidogenic phase, COD removal rate was stable at about 15%. In the steady operation period, the main liquid end products were ethanol and acetic acid, which represented ethanol type fermentation. Among the liquid end products, the concentration percentage of ethanol and acetic acid amounted to 69.5% - 89. 8% and the concentration percentage of ethanol took prominent about 51.7% - 59. 1%, which is better than the utilization of substrate for the methanogenic bacteria. An ethanol type fermentation pathway was suggested in the operation of enlarged industrial continuous hydrogen bio-producing reactors.展开更多
Energy recovery threshold logic (ERTL) is proposed,which combines threshold logic with adiabatic approach.ERTL achieves low energy as well as low gate complexity.A high efficiency power clock generator is also propose...Energy recovery threshold logic (ERTL) is proposed,which combines threshold logic with adiabatic approach.ERTL achieves low energy as well as low gate complexity.A high efficiency power clock generator is also proposed,which can adjust duty cycle of MOS switch in power clock generator depending on logic complexity and operating frequency to achieve optimum energy efficiency.Closed-form results are derived,which facilitate efficiency-optimized design of the power clock generator.An ERTL PLA and a conventional PLA are designed and simulated on 0.35μm process.The energy efficiency of the proposed power clock generator can reach 77%～85% operating between 20～100MHz.Simulation results indicate that ERTL is a low energy logic.Including power loss of power clock circuits,ERTL PLA still shows 65%～77% power savings compared to conventional PLA.展开更多
A novel energy recovery logic style ERCCL （energy recovery capacitance coupling logic） , which has good energy performance compared to the conventional CMOS logic and other advanced energy recovery logic, is propose...A novel energy recovery logic style ERCCL （energy recovery capacitance coupling logic） , which has good energy performance compared to the conventional CMOS logic and other advanced energy recovery logic, is proposed. ERCCL uses capacitance coupling to perform a logic function, so it can energy-efficiently implement a high fan-in complex logic in a single gate. ERCCL is also a type of threshold logic. The gate count of a system based on ERCCL can be significantly reduced,which,in turn,will decrease the energy loss. A threshold logic synthesis methodology for ERCCL is also presented. MCNC benchmarks are run through the proposed synthesis methodology. The results indicate that about an 80% reduction in gate count can be obtained when compared with the synthesis results of SIS.展开更多
Liquefied natural gas(LNG)is regarded as one of the cleanest fossil fuel and has experienced significant developments in recent years.The liquefaction process of natural gas is energy-intensive,while the regasificatio...Liquefied natural gas(LNG)is regarded as one of the cleanest fossil fuel and has experienced significant developments in recent years.The liquefaction process of natural gas is energy-intensive,while the regasification of LNG gives out a huge amount of waste energy since plenty of high grade cold energy(-160℃)from LNG is released to sea water directly in most cases,and also sometimes LNG is burned for regasification.On the other hand,liquid air energy storage(LAES)is an emerging energy storage technology for applications such as peak load shifting of power grids,which generates 30%-40%of compression heat(-200℃).Such heat could lead to energy waste if not recovered and used.The recovery of the compression heat is technically feasible but requires additional capital investment,which may not always be economically attractive.Therefore,we propose a power plant for recovering the waste cryogenic energy from LNG regasification and compression heat from the LAES.The challenge for such a power plant is the wide working temperature range between the low-temperature exergy source(-160℃)and heat source(-200℃).Nitrogen and argon are proposed as the working fluids to address the challenge.Thermodynamic analyses are carried out and the results show that the power plant could achieve a thermal efficiency of 27%and 19%and an exergy efficiency of 40%and 28%for nitrogen and argon,respectively.Here,with the nitrogen as working fluid undergoes a complete Brayton Cycle,while the argon based power plant goes through a combined Brayton and Rankine Cycle.Besides,the economic analysis shows that the payback period of this proposed system is only 2.2 years,utilizing the excess heat from a 5 MW/40 MWh LAES system.The findings suggest that the waste energy based power plant could be co-located with the LNG terminal and LAES plant,providing additional power output and reducing energy waste.展开更多
Currently, most developing countries have not set up municipal solid waste management systems with a view of recovering energy from waste or reducing greenhouse gas emissions. In this article, we have studied the poss...Currently, most developing countries have not set up municipal solid waste management systems with a view of recovering energy from waste or reducing greenhouse gas emissions. In this article, we have studied the possible effects of introducing three energy recovery processes either as a single or combination approach, refuse derived fuel production,incineration and waste power generation, and methane gas recovery from landfill and power generation in Ulaanbaatar, Mongolia, as a case study. We concluded that incineration process is the most suitable as first introduction of energy recovery. To operate it efficiently,3Rs strategies need to be promoted. And then, RDF production which is made of waste papers and plastics in high level of sorting may be considered as the second step of energy recovery.However, safety control and marketability of RDF will be required at that moment.展开更多
After analyzing the working condition of the conventional diesel forklift,an energy recovery system in hybrid forklift is considered and its simulation model is built.Then,the control strategy for the proposed energy ...After analyzing the working condition of the conventional diesel forklift,an energy recovery system in hybrid forklift is considered and its simulation model is built.Then,the control strategy for the proposed energy recovery system is discussed,which is validated and evaluated by simulation.The simulation results show that the proposed control strategy can achieve balance of the power and keep the state of charge(SOC) of ultra capacitor in a reasonable range,and the fuel consumption can be reduced by about 20.8% compared with the conventional diesel forklift.Finally,the feasibility of the simulation results is experimentally verified based on the lifting energy recovery system.展开更多
Globalization has led to a rapid rise in energy consumption,making climate change one of the world's most pressing issues.As wastewater treatment plants(WWTPs)contribute to climate change by emitting greenhouse ga...Globalization has led to a rapid rise in energy consumption,making climate change one of the world's most pressing issues.As wastewater treatment plants(WWTPs)contribute to climate change by emitting greenhouse gases(GHGs),this study estimated the total GHG emissions of WWTPs by classifying them as either direct or indirect carbon emissions.The effectiveness of the use of solar photovoltaic systems and biogas produced by WWTPs in increasing energy recovery and reducing GHG emissions was investigated.This study demonstrated that the use of an up-flow anaerobic sludge blanket(UASB)reactor with a biogas flow of 9120.77 m3/d and an activated sludge processing system(ASPS)reactor with a biogas flow of 14004 m^(3)/d,in addition to the energy production from the UASB reactor(6421.8 MW⸱h per year)and the ASPS reactor(9860.0 MW⸱h per year),yielded a reduction of 3316.85 and 5092.69 t of CO_(2)equivalent per year,respectively.Furthermore,the co-design of wastewater processes could be utilized to optimize biogas energy recovery.Moreover,the use of solar photovoltaic systems reduced GHG emissions from WWTPs.This is important to the transition to renewable energy because it resulted in a 10%-40%reduction in carbon emissions from WWTPs.Integrating renewable energy sources,biogas,and solar energy could provide up to 88%of the annual energy requirements of WWTPs.Recommendations are provided for further research considering the limited availability of integrated resources for studying the simultaneous utilization of photovoltaic and biogas systems.展开更多
An innovative idea of extracting kinetic energy from man-made wind resources using ducted turbine system for on-site power generation is introduced in this paper. A horizontal axis ducted turbine is attached to the to...An innovative idea of extracting kinetic energy from man-made wind resources using ducted turbine system for on-site power generation is introduced in this paper. A horizontal axis ducted turbine is attached to the top of the chimney to harness the kinetic energy of flue gases for producing electricity. The turbine system is positioned beyond the chimney outlet, to avoid any negative impact on the chimney performance. The convergentdivergent duct causes increase in the flue gas velocity and hence enhances the performance of the turbine. It also acts as a safety cover to the energy recovery system. The results from the CFD based simulation analysis indicate that sig- nificant power 34 kW can be harnessed from the chimney exhaust. The effect of airfoils NACA4412 and NACA4416 and the diffuser angle on the power extraction by the energy recovery system using a 6-bladed ducted turbine has been studied with the CFD simulation. It is observed that the average flue gas velocity in the duct section at the throat is approximately twice that of the inlet velocity, whereas maximum velocity achieved is 2.6 times the inlet velocity. The simulated results show that about power may be extracted from the chimney flue gases of 660 MW power plant. The system can be retrofitted to existing chimneys of thermal power plants, refineries and other industries.展开更多
A new integrated oil production enhancement technology based on water-flooding energy recovery is proposed.After providing an extensive review of the existing scientific and technical literature on this subject,the pr...A new integrated oil production enhancement technology based on water-flooding energy recovery is proposed.After providing an extensive review of the existing scientific and technical literature on this subject,the proposed integrated technology is described together with the related process flow diagram,the criteria used to select a tar-get facility for its implementation and the outcomes of the laboratory studies conducted to analyze emulsion formation and separation kinetics.Moreover,the outcomes of numerical simulations performed using Ansys CFX software are also presented.According to these results,using the proposed approach the incremental oil production may reach 1.2 t/day(with a 13%increase)and more,even at low flow rates(less than 10 t/day),thereby providing evidence for the benefits associated with this integrated technology.展开更多
Nowadays,AC electronic loads with energy recovery are widely used in the testing of uninterruptible power supplies and power supply equipment.To tackle the problems of control difficulty,strategy complexity,and poor d...Nowadays,AC electronic loads with energy recovery are widely used in the testing of uninterruptible power supplies and power supply equipment.To tackle the problems of control difficulty,strategy complexity,and poor dynamic performance of AC electronic load with energy recovery of the conventional control strategy,a control strategy of AC electronic load with energy recovery based on Finite Control Set Model Predictive Control(FCSMPC)is developed.To further reduce the computation burden of the FCS-MPC,a simplified FCS-MPC with transforming the predicted variables and using sector to select expected state is proposed.Through simplified model and equivalent approximation analysis,the transfer function of the system is obtained,and the stability and robustness of the system are analyzed.The performance of the simplified FCS-MPC is compared with space vector control(SVPWM)and conventional FCS-MPC.The results show that the FCS-MPC method performs better dynamic response and this advantage is more obvious when simulating high power loads.The simplified FCS-MPC shows similar control performance to conventional FCS-MPC at less computation burden.The control performance of the system also shows better simulation results.展开更多
Wireless sensor networks are widely used for monitoring in remote areas. They mainly consist of wireless sensor nodes, which are usually powered by batteries with limited capacity, but are expected to last for long pe...Wireless sensor networks are widely used for monitoring in remote areas. They mainly consist of wireless sensor nodes, which are usually powered by batteries with limited capacity, but are expected to last for long periods of time. To overcome these limitations and achieve perpetual autonomy, an energy harvesting technique using a thermoelectric generator (TEG) coupled with storage on supercapacitors is proposed. The originality of the work lies in the presentation of a maintenance-free, robust, and tested solution, well adapted to a harsh industrial context with a permanent temperature gradient. The harvesting part, which is attached to the hot spot in a few seconds using magnets, can withstand temperatures of 200°C. The storage unit, which contains the electronics and supercapacitors, operates at temperatures of up to 80°C. More specifically, this article describes the final design of a 3.3 V 60 mA battery-free power supply. An analysis of the thermal potential and the electrical power that can be recovered is presented, followed by the design of the main electronic stages: energy recovery using a BQ25504, storage on supercapacitors and finally shaping the output voltage with a boost (TPS610995) followed by an LDO (TPS71533).展开更多
The need to have naval units ever faster pushed the ship design to design hull shapes with increasingly higher performance thanks to the use of lightweight materials such as aluminum, and more powerful engines, etc., ...The need to have naval units ever faster pushed the ship design to design hull shapes with increasingly higher performance thanks to the use of lightweight materials such as aluminum, and more powerful engines, etc., but without substantially modifying the traditional forms of hull. The hull patented Monotricat high hydrodynamic efficiency and energy saving it represents an evolution of the traditional architectures of the hulls, as its shape is adapted to recover wave formation engendered from the bow and sprays associated with it so as to reduce the resistance to the benefit of the speed, and navigating in displacement at speeds of planing hulls with an efficiency of about 20%. The patented hull Monotricat represents the overcoming of distinction between displacement and planing hulls, because, unlike previous solutions, the hull conventionally called Monotricat is the first displacement hull that can navigate at both displacement and planning speeds, with a resistance curve almost straight, maintaining the characteristics of a displacement hull, since it combines the characteristics of displacement and planning hull. It presents an innovative architecture that could be defined as a hybrid between a monohull and catamaran, navigating on spray self-produced. The combination of these three types of naval hulls allows it to ensure： safety, comfort navigation, best seakeeping and maneuverability in restricted waters, stability, reduction of resistance to motion, cost management, regularity on the routes even in adverse weather-sea. These characteristics of the hull have been studied, tested and validated by leading research institutes and universities with more ameliorative results in each subsequent experimentation, reported in the present work, which demonstrated a greater hydrodynamic efficiency compared to conventional hulls of 20%.展开更多
We find nowadays in several fields of application the presence of IoT technology such as wireless sensor and actuator networks. In this technology, one of the main points of study is the management of energy consumpti...We find nowadays in several fields of application the presence of IoT technology such as wireless sensor and actuator networks. In this technology, one of the main points of study is the management of energy consumption. In this article, we provide a solar energy harvesting and storage system for powering wireless nodes. The system we propose uses a low power solar pane a P</span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">&</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">O control adapted to fuzzy logic for the MPPT. For energy storage, we used the supercapacitor technology. The simulation of the models shows better results than using the P</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">&</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">O command for an autonomous power supply of the wireless communicating nodes in the study region.展开更多
The waste referred to includes solid waste and sludge. Solid waste is mainly from urban garbage and industrial waste. Sludge is from water treatment factories, paper mills, chemical factories, pharmaceutical factories...The waste referred to includes solid waste and sludge. Solid waste is mainly from urban garbage and industrial waste. Sludge is from water treatment factories, paper mills, chemical factories, pharmaceutical factories, rivers and lakes. The waste and sludge are very harmful to water organisms, human health and drinking water, and directly affect the environment. Sludge and waste also occupy large areas of land. There are several methods to treat waste and sludge, such as burial, chemical treatment and incineration. Incineration is more effective than the展开更多
ABS is an active safety system which showed a valuable contribution to vehicle safety and stability since it was first introduced. Recently, EVs with in-wheel-motors have drawn increasing attention owing to their grea...ABS is an active safety system which showed a valuable contribution to vehicle safety and stability since it was first introduced. Recently, EVs with in-wheel-motors have drawn increasing attention owing to their greatest advantages. Wheels torques are precisely and swiftly controlled thanks to electric motors and their advanced driving techniques. In this paper, a regenerative-ABS control RABS is proposed for all-in-wheel-motors-drive EVs. The RABS is realized as a pure electronic braking system called brake-by-wire. A coordination strategy is suggested to control RABS compromising three layers. First, wheels slip control takes place, and braking torque is calculated in the higher layer. In the coordinate interlayer, torque is allocated between actuators ensuring maximal energy recovery and vehicle stability. While in the lower layer, actuator control is performed. The RABS effectiveness is validated on a 3-DOF EVSimulink model through two straight-line braking manoeuvres with low and high initial speeds of 50 km/h and 150 km/h, respectively. Both regular and emergency braking manoeuvres are considered with ABS enabled and disabled for comparison. Simulation results showed the high performance of the proposed RABS control in terms of vehicle stability, brake response, stopping distance, and battery re-charging.展开更多
This paper presents the control algorithm for supercapacitor based kinetic energy recovery system. Supercapacitor shares energy with the motor drive DC link through bidirectional non-isolated converter. Two cascaded l...This paper presents the control algorithm for supercapacitor based kinetic energy recovery system. Supercapacitor shares energy with the motor drive DC link through bidirectional non-isolated converter. Two cascaded linear regulators control feedback linearized states of the system. As a result, the DC link voltage is stabilized and the supercapacitor voltage and current are limited. Control algorithm does not increase ripple of voltages and currents, and thus life time expectancy of supercapacitor is prolonged. In torque-controlled motor drives, current on DC side can rapidly change with bandwidth as high as 2 kHz. Based on measurements of KERS states, the algorithm estimates rapidly changing motor drive current on DC side and stabilizes the DC link voltage with overshoot less than 2%. Controller is independent from the motor drive parameters and relies only on its own measurements. This enables kinetic energy recovery system （KERS） to be a standalone device.展开更多
基金supported by National Natural Science Foundation of China(Nos.52370025,22176012)BUCEA Post Graduate Innovation Project(No.PG2024086)。
文摘Sludge,the massive by-product of the sewage system,became a major challenge for the wastewater treatment industry.Yet,conventional methods often face challenges like low efficiency,high energy consumption,and environmental pollution.Especially,the improper treatment and disposal of toxic sludge generated from different industrial processes or specific wastewater treatment operations exerted significant pressure and threat to hydrosphere,pedosphere,atmosphere and even biosphere.
文摘This paper presents a new quasi-static single-phase energy recovery logic （QSSERL）, which unlike any other existing adiabatic logic family,uses a single sinusoidal supply-clock without additional timing control volta- ges. This not only ensures lower energy dissipation, but also simplifies the clock design, which would be otherwise more complicated due to the signal synchronization requirement. It is demonstrated that QSSERL circuits operate as fast as conventional two-phase energy recovery logic counterparts. Simulation with an 8bit logarithmic look- ahead adder （LLA） using static CMOS,clocked CMOS adiabatic logic （CAL,an existing typical single-phase ener- gy recovery logic）,and QSSERL,under 128 randomly generated input vectors,shows that the power consumption of the QSSERL adder is only 45% of that of the conventional static CMOS counterpart at 10MHz, and the QS- SERL adder achieves better energy efficiency than CAL when the input frequency finput is larger than 2MHz.
基金the Seawater Desalination Research Programs of Tianjin(043185211-4)
文摘Energy recovery device （ERD） is an important part of the seawater reverse osmosis （SWRO） desalination system. There are principally two kinds of ERDs, the centrifugal type and the positive displacement （PD） type. The PD type is of extensive concern and is preferred in large-scale plants. In this article, an innovative fluid switcher was presented and a two-cylinder hydraulic energy recovery unit with a lab-scale fluid switcher was set up. Tap water was used as the working medium instead of the actual seawater and brine in SWRO desalination plants. Under steady state operating conditions, the experimental results were obtained on the variations of the pressure and flow rate to and from the energy recovery unit. The hydraulic recovery efficiency （En） of the energy recovery unit with the fluid switcher reached up to 76.83%.
基金supported by Shanghai Science and Technology Committee(No.0904H155100)
文摘The purpose of this paper is to develop an implementable strategy of brake energy recovery for a parallel hydraulic hybrid bus. Based on brake process analysis, a dynamic programming algorithm of brake energy recovery is established. And then an implementable strategy of brake energy recovery is proposed by the constraint variable trajectories analysis of the dynamic programming algorithm in the typical urban bus cycle. The simulation results indicate the brake energy recovery efficiency of the accumulator can reach 60% in the dynamic programming algorithm. And the hydraulic hybrid system can output braking torque as much as possible.Moreover, the accumulator has almost equal efficiency of brake energy recovery between the implementable strategy and the dynamic programming algorithm. Therefore, the implementable strategy is very effective in improving the efficiency of brake energy recovery.The road tests show the fuel economy of the hydraulic hybrid bus improves by 22.6% compared with the conventional bus.
文摘A lab-scale expanded granular sludge bed （EGSB） reactor was employed to evaluate the feasibility of the hydrogen energy recovery potential from high strength organic wastewater. The results showed that a maximum hydrogen production rate of 7.43 m^3 H2/m^3 reactor · d and an average hydrogen production rate of 6.44- ms H^2/ms reactor · d were achieved with the hydrogen content of 50% -56% in the biogas during the 90-day operation. At the acidogenic phase, COD removal rate was stable at about 15%. In the steady operation period, the main liquid end products were ethanol and acetic acid, which represented ethanol type fermentation. Among the liquid end products, the concentration percentage of ethanol and acetic acid amounted to 69.5% - 89. 8% and the concentration percentage of ethanol took prominent about 51.7% - 59. 1%, which is better than the utilization of substrate for the methanogenic bacteria. An ethanol type fermentation pathway was suggested in the operation of enlarged industrial continuous hydrogen bio-producing reactors.
文摘Energy recovery threshold logic (ERTL) is proposed,which combines threshold logic with adiabatic approach.ERTL achieves low energy as well as low gate complexity.A high efficiency power clock generator is also proposed,which can adjust duty cycle of MOS switch in power clock generator depending on logic complexity and operating frequency to achieve optimum energy efficiency.Closed-form results are derived,which facilitate efficiency-optimized design of the power clock generator.An ERTL PLA and a conventional PLA are designed and simulated on 0.35μm process.The energy efficiency of the proposed power clock generator can reach 77%～85% operating between 20～100MHz.Simulation results indicate that ERTL is a low energy logic.Including power loss of power clock circuits,ERTL PLA still shows 65%～77% power savings compared to conventional PLA.
文摘A novel energy recovery logic style ERCCL （energy recovery capacitance coupling logic） , which has good energy performance compared to the conventional CMOS logic and other advanced energy recovery logic, is proposed. ERCCL uses capacitance coupling to perform a logic function, so it can energy-efficiently implement a high fan-in complex logic in a single gate. ERCCL is also a type of threshold logic. The gate count of a system based on ERCCL can be significantly reduced,which,in turn,will decrease the energy loss. A threshold logic synthesis methodology for ERCCL is also presented. MCNC benchmarks are run through the proposed synthesis methodology. The results indicate that about an 80% reduction in gate count can be obtained when compared with the synthesis results of SIS.
基金partial support of UK EPSRC under grants EP/V012053/1,EP/S032622/1,EP/P004709/1,EP/P003605/1 and EP/N032888/1the British Council under 2020-RLWK12-10478 and 2019-RLWK11-10724。
文摘Liquefied natural gas(LNG)is regarded as one of the cleanest fossil fuel and has experienced significant developments in recent years.The liquefaction process of natural gas is energy-intensive,while the regasification of LNG gives out a huge amount of waste energy since plenty of high grade cold energy(-160℃)from LNG is released to sea water directly in most cases,and also sometimes LNG is burned for regasification.On the other hand,liquid air energy storage(LAES)is an emerging energy storage technology for applications such as peak load shifting of power grids,which generates 30%-40%of compression heat(-200℃).Such heat could lead to energy waste if not recovered and used.The recovery of the compression heat is technically feasible but requires additional capital investment,which may not always be economically attractive.Therefore,we propose a power plant for recovering the waste cryogenic energy from LNG regasification and compression heat from the LAES.The challenge for such a power plant is the wide working temperature range between the low-temperature exergy source(-160℃)and heat source(-200℃).Nitrogen and argon are proposed as the working fluids to address the challenge.Thermodynamic analyses are carried out and the results show that the power plant could achieve a thermal efficiency of 27%and 19%and an exergy efficiency of 40%and 28%for nitrogen and argon,respectively.Here,with the nitrogen as working fluid undergoes a complete Brayton Cycle,while the argon based power plant goes through a combined Brayton and Rankine Cycle.Besides,the economic analysis shows that the payback period of this proposed system is only 2.2 years,utilizing the excess heat from a 5 MW/40 MWh LAES system.The findings suggest that the waste energy based power plant could be co-located with the LNG terminal and LAES plant,providing additional power output and reducing energy waste.
基金supported by the Showa Shell Sekiyu Foundation for the promotion of environmental researchpartially by the Asahi Glass Foundation (grant number 68)
文摘Currently, most developing countries have not set up municipal solid waste management systems with a view of recovering energy from waste or reducing greenhouse gas emissions. In this article, we have studied the possible effects of introducing three energy recovery processes either as a single or combination approach, refuse derived fuel production,incineration and waste power generation, and methane gas recovery from landfill and power generation in Ulaanbaatar, Mongolia, as a case study. We concluded that incineration process is the most suitable as first introduction of energy recovery. To operate it efficiently,3Rs strategies need to be promoted. And then, RDF production which is made of waste papers and plastics in high level of sorting may be considered as the second step of energy recovery.However, safety control and marketability of RDF will be required at that moment.
基金Project(2013BAF07B02)supported by National Science and Technology Support Program of China
文摘After analyzing the working condition of the conventional diesel forklift,an energy recovery system in hybrid forklift is considered and its simulation model is built.Then,the control strategy for the proposed energy recovery system is discussed,which is validated and evaluated by simulation.The simulation results show that the proposed control strategy can achieve balance of the power and keep the state of charge(SOC) of ultra capacitor in a reasonable range,and the fuel consumption can be reduced by about 20.8% compared with the conventional diesel forklift.Finally,the feasibility of the simulation results is experimentally verified based on the lifting energy recovery system.
文摘Globalization has led to a rapid rise in energy consumption,making climate change one of the world's most pressing issues.As wastewater treatment plants(WWTPs)contribute to climate change by emitting greenhouse gases(GHGs),this study estimated the total GHG emissions of WWTPs by classifying them as either direct or indirect carbon emissions.The effectiveness of the use of solar photovoltaic systems and biogas produced by WWTPs in increasing energy recovery and reducing GHG emissions was investigated.This study demonstrated that the use of an up-flow anaerobic sludge blanket(UASB)reactor with a biogas flow of 9120.77 m3/d and an activated sludge processing system(ASPS)reactor with a biogas flow of 14004 m^(3)/d,in addition to the energy production from the UASB reactor(6421.8 MW⸱h per year)and the ASPS reactor(9860.0 MW⸱h per year),yielded a reduction of 3316.85 and 5092.69 t of CO_(2)equivalent per year,respectively.Furthermore,the co-design of wastewater processes could be utilized to optimize biogas energy recovery.Moreover,the use of solar photovoltaic systems reduced GHG emissions from WWTPs.This is important to the transition to renewable energy because it resulted in a 10%-40%reduction in carbon emissions from WWTPs.Integrating renewable energy sources,biogas,and solar energy could provide up to 88%of the annual energy requirements of WWTPs.Recommendations are provided for further research considering the limited availability of integrated resources for studying the simultaneous utilization of photovoltaic and biogas systems.
文摘An innovative idea of extracting kinetic energy from man-made wind resources using ducted turbine system for on-site power generation is introduced in this paper. A horizontal axis ducted turbine is attached to the top of the chimney to harness the kinetic energy of flue gases for producing electricity. The turbine system is positioned beyond the chimney outlet, to avoid any negative impact on the chimney performance. The convergentdivergent duct causes increase in the flue gas velocity and hence enhances the performance of the turbine. It also acts as a safety cover to the energy recovery system. The results from the CFD based simulation analysis indicate that sig- nificant power 34 kW can be harnessed from the chimney exhaust. The effect of airfoils NACA4412 and NACA4416 and the diffuser angle on the power extraction by the energy recovery system using a 6-bladed ducted turbine has been studied with the CFD simulation. It is observed that the average flue gas velocity in the duct section at the throat is approximately twice that of the inlet velocity, whereas maximum velocity achieved is 2.6 times the inlet velocity. The simulated results show that about power may be extracted from the chimney flue gases of 660 MW power plant. The system can be retrofitted to existing chimneys of thermal power plants, refineries and other industries.
基金supported by the Government of Perm Krai,Research Project No.С-26/510。
文摘A new integrated oil production enhancement technology based on water-flooding energy recovery is proposed.After providing an extensive review of the existing scientific and technical literature on this subject,the proposed integrated technology is described together with the related process flow diagram,the criteria used to select a tar-get facility for its implementation and the outcomes of the laboratory studies conducted to analyze emulsion formation and separation kinetics.Moreover,the outcomes of numerical simulations performed using Ansys CFX software are also presented.According to these results,using the proposed approach the incremental oil production may reach 1.2 t/day(with a 13%increase)and more,even at low flow rates(less than 10 t/day),thereby providing evidence for the benefits associated with this integrated technology.
文摘Nowadays,AC electronic loads with energy recovery are widely used in the testing of uninterruptible power supplies and power supply equipment.To tackle the problems of control difficulty,strategy complexity,and poor dynamic performance of AC electronic load with energy recovery of the conventional control strategy,a control strategy of AC electronic load with energy recovery based on Finite Control Set Model Predictive Control(FCSMPC)is developed.To further reduce the computation burden of the FCS-MPC,a simplified FCS-MPC with transforming the predicted variables and using sector to select expected state is proposed.Through simplified model and equivalent approximation analysis,the transfer function of the system is obtained,and the stability and robustness of the system are analyzed.The performance of the simplified FCS-MPC is compared with space vector control(SVPWM)and conventional FCS-MPC.The results show that the FCS-MPC method performs better dynamic response and this advantage is more obvious when simulating high power loads.The simplified FCS-MPC shows similar control performance to conventional FCS-MPC at less computation burden.The control performance of the system also shows better simulation results.
文摘Wireless sensor networks are widely used for monitoring in remote areas. They mainly consist of wireless sensor nodes, which are usually powered by batteries with limited capacity, but are expected to last for long periods of time. To overcome these limitations and achieve perpetual autonomy, an energy harvesting technique using a thermoelectric generator (TEG) coupled with storage on supercapacitors is proposed. The originality of the work lies in the presentation of a maintenance-free, robust, and tested solution, well adapted to a harsh industrial context with a permanent temperature gradient. The harvesting part, which is attached to the hot spot in a few seconds using magnets, can withstand temperatures of 200°C. The storage unit, which contains the electronics and supercapacitors, operates at temperatures of up to 80°C. More specifically, this article describes the final design of a 3.3 V 60 mA battery-free power supply. An analysis of the thermal potential and the electrical power that can be recovered is presented, followed by the design of the main electronic stages: energy recovery using a BQ25504, storage on supercapacitors and finally shaping the output voltage with a boost (TPS610995) followed by an LDO (TPS71533).
文摘The need to have naval units ever faster pushed the ship design to design hull shapes with increasingly higher performance thanks to the use of lightweight materials such as aluminum, and more powerful engines, etc., but without substantially modifying the traditional forms of hull. The hull patented Monotricat high hydrodynamic efficiency and energy saving it represents an evolution of the traditional architectures of the hulls, as its shape is adapted to recover wave formation engendered from the bow and sprays associated with it so as to reduce the resistance to the benefit of the speed, and navigating in displacement at speeds of planing hulls with an efficiency of about 20%. The patented hull Monotricat represents the overcoming of distinction between displacement and planing hulls, because, unlike previous solutions, the hull conventionally called Monotricat is the first displacement hull that can navigate at both displacement and planning speeds, with a resistance curve almost straight, maintaining the characteristics of a displacement hull, since it combines the characteristics of displacement and planning hull. It presents an innovative architecture that could be defined as a hybrid between a monohull and catamaran, navigating on spray self-produced. The combination of these three types of naval hulls allows it to ensure： safety, comfort navigation, best seakeeping and maneuverability in restricted waters, stability, reduction of resistance to motion, cost management, regularity on the routes even in adverse weather-sea. These characteristics of the hull have been studied, tested and validated by leading research institutes and universities with more ameliorative results in each subsequent experimentation, reported in the present work, which demonstrated a greater hydrodynamic efficiency compared to conventional hulls of 20%.
文摘We find nowadays in several fields of application the presence of IoT technology such as wireless sensor and actuator networks. In this technology, one of the main points of study is the management of energy consumption. In this article, we provide a solar energy harvesting and storage system for powering wireless nodes. The system we propose uses a low power solar pane a P</span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">&</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">O control adapted to fuzzy logic for the MPPT. For energy storage, we used the supercapacitor technology. The simulation of the models shows better results than using the P</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">&</span></span></span><span><span><span style="font-family:""> </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">O command for an autonomous power supply of the wireless communicating nodes in the study region.
文摘The waste referred to includes solid waste and sludge. Solid waste is mainly from urban garbage and industrial waste. Sludge is from water treatment factories, paper mills, chemical factories, pharmaceutical factories, rivers and lakes. The waste and sludge are very harmful to water organisms, human health and drinking water, and directly affect the environment. Sludge and waste also occupy large areas of land. There are several methods to treat waste and sludge, such as burial, chemical treatment and incineration. Incineration is more effective than the
文摘ABS is an active safety system which showed a valuable contribution to vehicle safety and stability since it was first introduced. Recently, EVs with in-wheel-motors have drawn increasing attention owing to their greatest advantages. Wheels torques are precisely and swiftly controlled thanks to electric motors and their advanced driving techniques. In this paper, a regenerative-ABS control RABS is proposed for all-in-wheel-motors-drive EVs. The RABS is realized as a pure electronic braking system called brake-by-wire. A coordination strategy is suggested to control RABS compromising three layers. First, wheels slip control takes place, and braking torque is calculated in the higher layer. In the coordinate interlayer, torque is allocated between actuators ensuring maximal energy recovery and vehicle stability. While in the lower layer, actuator control is performed. The RABS effectiveness is validated on a 3-DOF EVSimulink model through two straight-line braking manoeuvres with low and high initial speeds of 50 km/h and 150 km/h, respectively. Both regular and emergency braking manoeuvres are considered with ABS enabled and disabled for comparison. Simulation results showed the high performance of the proposed RABS control in terms of vehicle stability, brake response, stopping distance, and battery re-charging.
文摘This paper presents the control algorithm for supercapacitor based kinetic energy recovery system. Supercapacitor shares energy with the motor drive DC link through bidirectional non-isolated converter. Two cascaded linear regulators control feedback linearized states of the system. As a result, the DC link voltage is stabilized and the supercapacitor voltage and current are limited. Control algorithm does not increase ripple of voltages and currents, and thus life time expectancy of supercapacitor is prolonged. In torque-controlled motor drives, current on DC side can rapidly change with bandwidth as high as 2 kHz. Based on measurements of KERS states, the algorithm estimates rapidly changing motor drive current on DC side and stabilizes the DC link voltage with overshoot less than 2%. Controller is independent from the motor drive parameters and relies only on its own measurements. This enables kinetic energy recovery system （KERS） to be a standalone device.
