As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crud...As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crude oil gathering and transportation systems and identify the energy efficiency gaps.In this paper,the energy efficiency evaluation system of the crude oil gathering and transportation system in an oilfield in western China is established.Combined with the big data analysis method,the GA-BP neural network is used to establish the energy efficiency index prediction model for crude oil gathering and transportation systems.The comprehensive energy consumption,gas consumption,power consumption,energy utilization rate,heat utilization rate,and power utilization rate of crude oil gathering and transportation systems are predicted.Considering the efficiency and unit consumption index of the crude oil gathering and transportation system,the energy efficiency evaluation system of the crude oil gathering and transportation system is established based on a game theory combined weighting method and TOPSIS evaluation method,and the subjective weight is determined by the triangular fuzzy analytic hierarchy process.The entropy weight method determines the objective weight,and the combined weight of game theory combines subjectivity with objectivity to comprehensively evaluate the comprehensive energy efficiency of crude oil gathering and transportation systems and their subsystems.Finally,the weak links in energy utilization are identified,and energy conservation and consumption reduction are improved.The above research provides technical support for the green,efficient and intelligent development of crude oil gathering and transportation systems.展开更多
Hotel buildings are currently among the largest energy consumers in the world.Heating,ventilation,and air conditioning are the most energy-intensive building systems,accounting for more than half of total energy consu...Hotel buildings are currently among the largest energy consumers in the world.Heating,ventilation,and air conditioning are the most energy-intensive building systems,accounting for more than half of total energy consumption.An energy audit is used to predict the weak points of a building’s energy use system.Various factors influence building energy consumption,which can be modified to achieve more energy-efficient strategies.In this study,an existing hotel building in Central Taiwan is evaluated by simulating several scenarios using energy modeling over a year.Energy modeling is conducted by using Autodesk Revit 2025.It was discovered from the results that arranging the lighting schedule based on the ASHRAE Standard 90.1 could save up to 8.22%of energy consumption.And then the results also revealed that changing the glazing of the building into double-layer lowemissivity glass could reduce energy consumption by 14.58%.While the energy consumption of the building could also be decreased to 7.20%by changing the building orientation to the north.Meanwhile,moving the building location to Northern Taiwan could also minimize the energy consumption of the building by 3.23%.The results revealed that the double layer offers better thermal insulation,and low-emissivity glass can lower energy consumption,electricity costs,and CO_(2)emissions by up to 15.27%annually.While adjusting orientation and location can enhance energy performance,this approach is impractical for existing buildings,but this could be considered for designing new buildings.The results showed the relevancy of energy performance to CO_(2)emission production and electricity expenses.展开更多
In the hot summer&cold winter zone in China,intermittent heating space for rooms is widely used.However,in comparison with continuous space heating,the energy-saving performance of intermittent space heating has n...In the hot summer&cold winter zone in China,intermittent heating space for rooms is widely used.However,in comparison with continuous space heating,the energy-saving performance of intermittent space heating has not been sufficiently investigated.This paper studied the factors influencing the energy performance of intermittent heating for the representativeoffice inhot summer&coldwinter zone.Basedon theheatbalancemethod,adynamic thermalmodel of the intermittent heating roomwas built and tested by experiments.And then,it analyzed the total space heating load,the amount of energy saving and energy saving ratio of the intermittent heating under different preheating hours,occupation hours,required roomtemperatures,air change rates,overall heat transfer coefficients(U-value)of windows and wall materials.If the adjacent rooms were not heated,for a typical room occupied about 10 h a day,the energy-saving ratio of intermittent heating was about 30%compared with continuous heating.But the preheating power was higher than two times of continuous heating.The results also indicated that the occupation hours had a significant effect on energy saving amount and ratio,it should be noted that the energy saving ratio by intermittent heating was much lower than the unoccupied period ratio.Relative to other factors,the heating temperatures,room air change rates and U-value of windows,and room envelope materials had little effect on energy efficiency.If the adjacent rooms were heated in the same manner as the roomin question,the energy-saving ratio of the total load of intermittent heating was heavily reduced to 8.46%.展开更多
A hybrid ground-coupled heat pump(HGCHP)project in Nanjing,China is chosen to analyze the building energy-consumption properties in terms of different control strategies,building envelope and the terminal air-condit...A hybrid ground-coupled heat pump(HGCHP)project in Nanjing,China is chosen to analyze the building energy-consumption properties in terms of different control strategies,building envelope and the terminal air-conditioning system.The HGCHP uses a supplemental heat rejecter to dissipate extra thermal energy to guarantee underground soil heat balance.The software EnergyPlus is employed to simulate the project and design the heat flow of the cooling tower and the borehole heat exchanger(BHE).Then two feasible control strategies for the cooling tower and the borehole heat exchanger are proposed.The energy-saving potential of the building envelope is analyzed in terms of the surface color of the wall/roof.With the same terminal system,it is found that in the cooling season the heat flow of the insulated building with black wall/roof is 1.2 times more than that with white wall/roof.With the same insulated building and gray wall/roof,it is concluded that the heat pump units for a primary air fan-coil system show an annual energy consumption increase of 44.7 GJ compared with a radiant floor system.展开更多
It was proposed that park planning should be based on local economic development,should focus on the preservation of primitive ecological conditions and the application of low-carbon and energy-saving concepts.The pla...It was proposed that park planning should be based on local economic development,should focus on the preservation of primitive ecological conditions and the application of low-carbon and energy-saving concepts.The planning of Ancient Banyan Park in Mengshan County by following the principles of respecting local history and culture,improving functions and supporting facilities,human-centered,overall planning and all-around consideration,respecting characteristics of the local area(the planning site),satisfying operation requirements of the park,applying low-carbon and energy-saving concepts,and avoiding over-engineering,aimed at protecting natural images of the park,primitive history,culture and characteristics of the local area and providing a space for local residents' various activities.Modern aesthetic forms were combined,cultural connotation of natural environment stressed to build a landscape space system of the Ancient Banyan Park that matches well with environment of the planning site.The park was designed into 4 functional areas:sport area,fitness plaza area,garden recreational area and ancient banyan cultural area.Different functions of these subareas were taken into consideration to create conservation-minded garden landscapes which were both independent and unified.展开更多
By investigating present relocation residential districts for peasants whose houses are removed for the unified planning of rural areas in north Jiangsu Province, as well as residents' feelings about the environme...By investigating present relocation residential districts for peasants whose houses are removed for the unified planning of rural areas in north Jiangsu Province, as well as residents' feelings about the environment of residential district, main architectural structures and energy consumption conditions, the indoor thermal environment, use of main heating and cooling facilities, residents' satisfaction on the acoustical and luminous environment, major space-enclosing structures and calculation of energy-saving designs are analyzed, and suggestions are given for the architectural design of relocation residential districts in the study area. It is stressed that the relationship between energy conservation and architectural layout, orientation, lighting, ventilation, selection of enclosing-structure materials, facade, color and style should be properly handled in the planning, and the focus is to control building orientation and shape coefficient, on the basis of which energy-saving designs of windows, exterior walls and roofs can be done. Energy consumption of present residential buildings is calculated and analyzed to bring forth new ideas to the energy-saving designs for relocation residential districts in north Jiangsu Province, and establish an architectural energy-saving system suitable for climatic and natural conditions of north Jiangsu to instruct the energy-saving designs of relocation residential districts in the study area.展开更多
Currently, many studies have been made for years on dimensions of pneumatic nozzle, which influence the flow characteristic of blowing system. For the purpose of outputting the same blowing force, the supply pressure ...Currently, many studies have been made for years on dimensions of pneumatic nozzle, which influence the flow characteristic of blowing system. For the purpose of outputting the same blowing force, the supply pressure could be reduced by decreasing the ratio of length to diameter of nozzle. The friction between high speed air and pipe wall would be reduced if the nozzle is designed to be converging shape comparing with straight shape. But the volume flow and pressure, discussed in these studies, do not describe energy loss of the blowing system directly. Pneumatic power is an innovative principle to estimate pneumatic system’s energy consumption directly. Based on the above principle, a pulse blowing method is put forward for saving energy. A flow experiment is carried out, in which the high speed air flows from the pulse blowing system and continuous blowing system respectively to a plate with grease on top. Supply pressure and the volume of air used for removing the grease are measured to calculate energy consumption. From the experiment result, the pulse blowing system performs to conserve energy comparing with the continuous blowing system. The frequency and duty ratio of pulse flow influence the blowing characteristic. The pulse blowing system performs to be the most efficient at the specified frequency and duty ratio. Then a pneumatic self-oscillated method based on air operated valve is put forward to generate pulse flow. A simulation is made about dynamic modeling the air operated valve and calculating the motion of the valve core and output pressure. The simulation result verifies the system to be able to generate pulse flow, and predicts the key parameters of the frequency and duty ratio measured by experiment well. Finally, on the basis of simplifying and solution of the pulse blowing system’s mathematic model, the relationship between system’s frequency duty ratio and the dimensions of components is simply described with four algebraic equations. The system could be designed with specified frequency and duty ratio according to the four equations. This study provides theoretical basis for designing energy-saving air blowing system.展开更多
To improve high-speed road feel and enhance energetic efficiency of hydraulic power steering(HPS) system in heavy-duty vehicles, an electromagnetic slip coupling(ESC) was applied to the steering system, which regulate...To improve high-speed road feel and enhance energetic efficiency of hydraulic power steering(HPS) system in heavy-duty vehicles, an electromagnetic slip coupling(ESC) was applied to the steering system, which regulated discharge flow of steering pump to realize variable assist characteristic as well as uniquely transfer on-demand power from engine to steering pump. The model of ESC was established and the dynamic characteristics of ESC were presented by the way of simulation and experiment. Upon the layout of the assist characteristics, output torque of ESC was derived. Based on the ESC model, the output torque characteristics of ESC were simulated under steering situation and straight driving situation, respectively. The consistency of simulated ESC output torque and the one deduced from assist characteristics verifies the correctness of the ESC dynamic model. To illustrate energy saving characteristics of ESC-HPS, energy consumption comparison of ESC-HPS and conventional HPS was carried out qualitatively and quantitatively. It follows that the energy consumption of ESC-HPS decreases by 50% compared with that of HPS.展开更多
Energy consumption of block-cutting machines represents a major cost item in the processing of travertines and other natural stones. Therefore, determining the optimum sawing conditions for a particular stone is of ma...Energy consumption of block-cutting machines represents a major cost item in the processing of travertines and other natural stones. Therefore, determining the optimum sawing conditions for a particular stone is of major importance in the natural stone-processing industry. An experimental study was carried out utilizing a fully instrumented block-cutter to investigate the sawing performances of five different types of travertine blocks during cutting with a circular diamond saw. The sawing tests were performed in the down-cutting mode. Performance measurements were determined by measuring the cutting speed and energy consumption. Then, specific energy was determined. The one main cutting parameter, cutting speed, was varied in the investigation of optimum cutting performance. Furthermore, some physico-mechanical properties of file travertine blocks were determined in the laboratory. As a result, it is found that the energy consumption (specific energy) of block cutting machines is highly affected by cutting speed. It is determined that specific energy value usually decreases when cutting speed increases. When the cutting speed is higher than the determined value, the diamond saw can become stuck in the travertine block; this situation can be a problem for the block-cutting machine. As a result, the optimum cutting speed obtained for the travertine mines examined is approximately 1.5-2.0 m/min.展开更多
A problem of peak power in DC-electrified railway systems is mainly caused by train power demand during acceleration.If this power is reduced,substation peak power will be significantly decreased.This paper presents a...A problem of peak power in DC-electrified railway systems is mainly caused by train power demand during acceleration.If this power is reduced,substation peak power will be significantly decreased.This paper presents a study on optimal energy saving in DC-electrified railway with on-board energy storage system(OBESS) by using peak demand cutting strategy under different trip time controls.The proposed strategy uses OBESS to store recovered braking energy and find an appropriated time to deliver the stored energy back to the power network in such a way that peak power of every substations is reduced.Bangkok Mass Transit System(BTS)-Silom Line in Thailand is used to test and verify the proposed strategy.The results show that substation peak power is reduced by63.49% and net energy consumption is reduced by 15.56%using coasting and deceleration trip time control.展开更多
China has achieved economic growth while great carbon emissions reduction in recent years. Amid China's effort to reduce emissions, the Five-Year Plans have guided and motivated local and foreign forces from the gove...China has achieved economic growth while great carbon emissions reduction in recent years. Amid China's effort to reduce emissions, the Five-Year Plans have guided and motivated local and foreign forces from the government, industries, and society to work together. This paper showed that a mediumehigh economic growth gate, industry structure adjustment, and energy structure adjustment, which are guaranteed under the Five-Year Plan, all contribute to energy saving in China. The economy entered a stable growing phase during the 12 th Five-Year Plan, while the economic growth rate declined to 7.8% from 11.2% in the 11 th Five-Year Plan. Simultaneously, the CO2 emissions growth rate declined from8.32%(2009-2012 mean) to 1.82%(2012-2014 mean). Industrial structure adjustment canceled out nearly one-third of the CO2 emissions caused by economic growth. Under the 13 th Five-Year Plan, China will continue its energy saving efforts on the green development path, with greener quotas, a stricter implementation process, and more key projects.展开更多
Mining shovel is a crucial piece of equipment for high-efficiency production in open-pit mining and stands as one of the largest energy consumption sources in mining.However,substantial energy waste occurs during the ...Mining shovel is a crucial piece of equipment for high-efficiency production in open-pit mining and stands as one of the largest energy consumption sources in mining.However,substantial energy waste occurs during the descent of the hoisting system or the deceleration of the slewing platform.To reduce the energy loss,an innovative hydrau-lic-electric hybrid drive system is proposed,in which a hydraulic pump/motor connected with an accumulator is added to assist the electric motor to drive the hoisting system or slewing platform,recycling kinetic and potential energy.The utilization of the kinetic and potential energy reduces the energy loss and installed power of the min-ing shovel.Meanwhile,the reliability of the mining shovel pure electric drive system also can be increased.In this paper,the hydraulic-electric hybrid driving principle is introduced,a small-scale testbed is set up to verify the feasibil-ity of the system,and a co-simulation model of the proposed system is established to clarify the system operation and energy characteristics.The test and simulation results show that,by adopting the proposed system,compared with the traditional purely electric driving system,the peak power and energy consumption of the hoisting electric motor are reduced by 36.7%and 29.7%,respectively.Similarly,the slewing electric motor experiences a significant decrease in peak power by 86.9%and a reduction in energy consumption by 59.4%.The proposed system expands the application area of the hydraulic electric hybrid drive system and provides a reference for its application in over-sized and super heavy equipment.展开更多
When saving energy in a pneumatic system,the problem of energy losses is usually solved by reducing the air supply pressure.The power-matching method is applied to optimize the air-supply pressure of the pneumatic sys...When saving energy in a pneumatic system,the problem of energy losses is usually solved by reducing the air supply pressure.The power-matching method is applied to optimize the air-supply pressure of the pneumatic system,and the energy-saving effect is verified by experiments.First,the experimental platform of a pneumatic rotary actuator servo-control system is built,and the mechanism of the valve-controlled cylinder system is analyzed.Then,the output power characteristics and load characteristics of the system are derived,and their characteristic curves are drawn.The employed air compressor is considered as a constant-pressure source of a quantitative pump,and the power characteristic of the system is matched.The power source characteristic curve should envelope the output characteristic curve and load characteristic curve.The minimum gas supply pressure obtained by power matching represents the optimal gas supply pressure.The comparative experiments under two different gas supply pressure conditions show that the system under the optimal gas supply pressure can greatly reduce energy losses.展开更多
Copper-zinc alloy element for boiler energy saving was put in the intake of simulated boiler system to investigate the interaction and transfer of ions in water system both theoretically and experimentally.The fouling...Copper-zinc alloy element for boiler energy saving was put in the intake of simulated boiler system to investigate the interaction and transfer of ions in water system both theoretically and experimentally.The fouling was analyzed by scanning electron microscopy(SEM)and energy dispersive X-ray detector(EDX).The results show that the transfer of calcium and magnesium ions in heat-transfer-surface-water system is affected by zinc ions dissolved from the alloy because of primary battery reaction.Some calcium ions of calcium carbonate crystal are replaced by zinc ions,the growth of aragonite crystal nucleus is retarded,and the transition of calcium carbonate from aragonite to calcite is hampered.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(52074089 and 52104064)Natural Science Foundation of Heilongjiang Province of China(LH2019E019).
文摘As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crude oil gathering and transportation systems and identify the energy efficiency gaps.In this paper,the energy efficiency evaluation system of the crude oil gathering and transportation system in an oilfield in western China is established.Combined with the big data analysis method,the GA-BP neural network is used to establish the energy efficiency index prediction model for crude oil gathering and transportation systems.The comprehensive energy consumption,gas consumption,power consumption,energy utilization rate,heat utilization rate,and power utilization rate of crude oil gathering and transportation systems are predicted.Considering the efficiency and unit consumption index of the crude oil gathering and transportation system,the energy efficiency evaluation system of the crude oil gathering and transportation system is established based on a game theory combined weighting method and TOPSIS evaluation method,and the subjective weight is determined by the triangular fuzzy analytic hierarchy process.The entropy weight method determines the objective weight,and the combined weight of game theory combines subjectivity with objectivity to comprehensively evaluate the comprehensive energy efficiency of crude oil gathering and transportation systems and their subsystems.Finally,the weak links in energy utilization are identified,and energy conservation and consumption reduction are improved.The above research provides technical support for the green,efficient and intelligent development of crude oil gathering and transportation systems.
基金support by the National Science and Technology Council under grant no.NSTC 112-2221-E-167-017-MY3.
文摘Hotel buildings are currently among the largest energy consumers in the world.Heating,ventilation,and air conditioning are the most energy-intensive building systems,accounting for more than half of total energy consumption.An energy audit is used to predict the weak points of a building’s energy use system.Various factors influence building energy consumption,which can be modified to achieve more energy-efficient strategies.In this study,an existing hotel building in Central Taiwan is evaluated by simulating several scenarios using energy modeling over a year.Energy modeling is conducted by using Autodesk Revit 2025.It was discovered from the results that arranging the lighting schedule based on the ASHRAE Standard 90.1 could save up to 8.22%of energy consumption.And then the results also revealed that changing the glazing of the building into double-layer lowemissivity glass could reduce energy consumption by 14.58%.While the energy consumption of the building could also be decreased to 7.20%by changing the building orientation to the north.Meanwhile,moving the building location to Northern Taiwan could also minimize the energy consumption of the building by 3.23%.The results revealed that the double layer offers better thermal insulation,and low-emissivity glass can lower energy consumption,electricity costs,and CO_(2)emissions by up to 15.27%annually.While adjusting orientation and location can enhance energy performance,this approach is impractical for existing buildings,but this could be considered for designing new buildings.The results showed the relevancy of energy performance to CO_(2)emission production and electricity expenses.
基金supported by the National Natural Science Foundation of China(No.71974129).
文摘In the hot summer&cold winter zone in China,intermittent heating space for rooms is widely used.However,in comparison with continuous space heating,the energy-saving performance of intermittent space heating has not been sufficiently investigated.This paper studied the factors influencing the energy performance of intermittent heating for the representativeoffice inhot summer&coldwinter zone.Basedon theheatbalancemethod,adynamic thermalmodel of the intermittent heating roomwas built and tested by experiments.And then,it analyzed the total space heating load,the amount of energy saving and energy saving ratio of the intermittent heating under different preheating hours,occupation hours,required roomtemperatures,air change rates,overall heat transfer coefficients(U-value)of windows and wall materials.If the adjacent rooms were not heated,for a typical room occupied about 10 h a day,the energy-saving ratio of intermittent heating was about 30%compared with continuous heating.But the preheating power was higher than two times of continuous heating.The results also indicated that the occupation hours had a significant effect on energy saving amount and ratio,it should be noted that the energy saving ratio by intermittent heating was much lower than the unoccupied period ratio.Relative to other factors,the heating temperatures,room air change rates and U-value of windows,and room envelope materials had little effect on energy efficiency.If the adjacent rooms were heated in the same manner as the roomin question,the energy-saving ratio of the total load of intermittent heating was heavily reduced to 8.46%.
文摘A hybrid ground-coupled heat pump(HGCHP)project in Nanjing,China is chosen to analyze the building energy-consumption properties in terms of different control strategies,building envelope and the terminal air-conditioning system.The HGCHP uses a supplemental heat rejecter to dissipate extra thermal energy to guarantee underground soil heat balance.The software EnergyPlus is employed to simulate the project and design the heat flow of the cooling tower and the borehole heat exchanger(BHE).Then two feasible control strategies for the cooling tower and the borehole heat exchanger are proposed.The energy-saving potential of the building envelope is analyzed in terms of the surface color of the wall/roof.With the same terminal system,it is found that in the cooling season the heat flow of the insulated building with black wall/roof is 1.2 times more than that with white wall/roof.With the same insulated building and gray wall/roof,it is concluded that the heat pump units for a primary air fan-coil system show an annual energy consumption increase of 44.7 GJ compared with a radiant floor system.
基金Supported by Scientific Research Program of Guangxi Provincial Department of Education(201010LX014)~~
文摘It was proposed that park planning should be based on local economic development,should focus on the preservation of primitive ecological conditions and the application of low-carbon and energy-saving concepts.The planning of Ancient Banyan Park in Mengshan County by following the principles of respecting local history and culture,improving functions and supporting facilities,human-centered,overall planning and all-around consideration,respecting characteristics of the local area(the planning site),satisfying operation requirements of the park,applying low-carbon and energy-saving concepts,and avoiding over-engineering,aimed at protecting natural images of the park,primitive history,culture and characteristics of the local area and providing a space for local residents' various activities.Modern aesthetic forms were combined,cultural connotation of natural environment stressed to build a landscape space system of the Ancient Banyan Park that matches well with environment of the planning site.The park was designed into 4 functional areas:sport area,fitness plaza area,garden recreational area and ancient banyan cultural area.Different functions of these subareas were taken into consideration to create conservation-minded garden landscapes which were both independent and unified.
基金Supported by Talent-Introduction Scientific Research Program of Yancheng Institute of Technology(XKR2011078)~~
文摘By investigating present relocation residential districts for peasants whose houses are removed for the unified planning of rural areas in north Jiangsu Province, as well as residents' feelings about the environment of residential district, main architectural structures and energy consumption conditions, the indoor thermal environment, use of main heating and cooling facilities, residents' satisfaction on the acoustical and luminous environment, major space-enclosing structures and calculation of energy-saving designs are analyzed, and suggestions are given for the architectural design of relocation residential districts in the study area. It is stressed that the relationship between energy conservation and architectural layout, orientation, lighting, ventilation, selection of enclosing-structure materials, facade, color and style should be properly handled in the planning, and the focus is to control building orientation and shape coefficient, on the basis of which energy-saving designs of windows, exterior walls and roofs can be done. Energy consumption of present residential buildings is calculated and analyzed to bring forth new ideas to the energy-saving designs for relocation residential districts in north Jiangsu Province, and establish an architectural energy-saving system suitable for climatic and natural conditions of north Jiangsu to instruct the energy-saving designs of relocation residential districts in the study area.
文摘Currently, many studies have been made for years on dimensions of pneumatic nozzle, which influence the flow characteristic of blowing system. For the purpose of outputting the same blowing force, the supply pressure could be reduced by decreasing the ratio of length to diameter of nozzle. The friction between high speed air and pipe wall would be reduced if the nozzle is designed to be converging shape comparing with straight shape. But the volume flow and pressure, discussed in these studies, do not describe energy loss of the blowing system directly. Pneumatic power is an innovative principle to estimate pneumatic system’s energy consumption directly. Based on the above principle, a pulse blowing method is put forward for saving energy. A flow experiment is carried out, in which the high speed air flows from the pulse blowing system and continuous blowing system respectively to a plate with grease on top. Supply pressure and the volume of air used for removing the grease are measured to calculate energy consumption. From the experiment result, the pulse blowing system performs to conserve energy comparing with the continuous blowing system. The frequency and duty ratio of pulse flow influence the blowing characteristic. The pulse blowing system performs to be the most efficient at the specified frequency and duty ratio. Then a pneumatic self-oscillated method based on air operated valve is put forward to generate pulse flow. A simulation is made about dynamic modeling the air operated valve and calculating the motion of the valve core and output pressure. The simulation result verifies the system to be able to generate pulse flow, and predicts the key parameters of the frequency and duty ratio measured by experiment well. Finally, on the basis of simplifying and solution of the pulse blowing system’s mathematic model, the relationship between system’s frequency duty ratio and the dimensions of components is simply described with four algebraic equations. The system could be designed with specified frequency and duty ratio according to the four equations. This study provides theoretical basis for designing energy-saving air blowing system.
基金Project(51275211)supported by the National Natural Science Foundation of ChinaProject(11KJA580001)supported by the Natural Science Fund for Colleges and Universities in Jiangsu Province,ChinaProject(CXZZ12_0665)supported by the Postgraduate Innovation Natural Science Foundation of Jiangsu Province,China
文摘To improve high-speed road feel and enhance energetic efficiency of hydraulic power steering(HPS) system in heavy-duty vehicles, an electromagnetic slip coupling(ESC) was applied to the steering system, which regulated discharge flow of steering pump to realize variable assist characteristic as well as uniquely transfer on-demand power from engine to steering pump. The model of ESC was established and the dynamic characteristics of ESC were presented by the way of simulation and experiment. Upon the layout of the assist characteristics, output torque of ESC was derived. Based on the ESC model, the output torque characteristics of ESC were simulated under steering situation and straight driving situation, respectively. The consistency of simulated ESC output torque and the one deduced from assist characteristics verifies the correctness of the ESC dynamic model. To illustrate energy saving characteristics of ESC-HPS, energy consumption comparison of ESC-HPS and conventional HPS was carried out qualitatively and quantitatively. It follows that the energy consumption of ESC-HPS decreases by 50% compared with that of HPS.
文摘Energy consumption of block-cutting machines represents a major cost item in the processing of travertines and other natural stones. Therefore, determining the optimum sawing conditions for a particular stone is of major importance in the natural stone-processing industry. An experimental study was carried out utilizing a fully instrumented block-cutter to investigate the sawing performances of five different types of travertine blocks during cutting with a circular diamond saw. The sawing tests were performed in the down-cutting mode. Performance measurements were determined by measuring the cutting speed and energy consumption. Then, specific energy was determined. The one main cutting parameter, cutting speed, was varied in the investigation of optimum cutting performance. Furthermore, some physico-mechanical properties of file travertine blocks were determined in the laboratory. As a result, it is found that the energy consumption (specific energy) of block cutting machines is highly affected by cutting speed. It is determined that specific energy value usually decreases when cutting speed increases. When the cutting speed is higher than the determined value, the diamond saw can become stuck in the travertine block; this situation can be a problem for the block-cutting machine. As a result, the optimum cutting speed obtained for the travertine mines examined is approximately 1.5-2.0 m/min.
文摘A problem of peak power in DC-electrified railway systems is mainly caused by train power demand during acceleration.If this power is reduced,substation peak power will be significantly decreased.This paper presents a study on optimal energy saving in DC-electrified railway with on-board energy storage system(OBESS) by using peak demand cutting strategy under different trip time controls.The proposed strategy uses OBESS to store recovered braking energy and find an appropriated time to deliver the stored energy back to the power network in such a way that peak power of every substations is reduced.Bangkok Mass Transit System(BTS)-Silom Line in Thailand is used to test and verify the proposed strategy.The results show that substation peak power is reduced by63.49% and net energy consumption is reduced by 15.56%using coasting and deceleration trip time control.
基金supported by the "study of Green space management system and protection" of mechanism Economic Development Research Center of State Forestry Administration (ZDWT-2014-3)
文摘China has achieved economic growth while great carbon emissions reduction in recent years. Amid China's effort to reduce emissions, the Five-Year Plans have guided and motivated local and foreign forces from the government, industries, and society to work together. This paper showed that a mediumehigh economic growth gate, industry structure adjustment, and energy structure adjustment, which are guaranteed under the Five-Year Plan, all contribute to energy saving in China. The economy entered a stable growing phase during the 12 th Five-Year Plan, while the economic growth rate declined to 7.8% from 11.2% in the 11 th Five-Year Plan. Simultaneously, the CO2 emissions growth rate declined from8.32%(2009-2012 mean) to 1.82%(2012-2014 mean). Industrial structure adjustment canceled out nearly one-third of the CO2 emissions caused by economic growth. Under the 13 th Five-Year Plan, China will continue its energy saving efforts on the green development path, with greener quotas, a stricter implementation process, and more key projects.
基金Supported by National Natural Science Foundation of China(Grant No.U1910211)National Key Research and Development Program of China(Grant No.2021YFB2011903).
文摘Mining shovel is a crucial piece of equipment for high-efficiency production in open-pit mining and stands as one of the largest energy consumption sources in mining.However,substantial energy waste occurs during the descent of the hoisting system or the deceleration of the slewing platform.To reduce the energy loss,an innovative hydrau-lic-electric hybrid drive system is proposed,in which a hydraulic pump/motor connected with an accumulator is added to assist the electric motor to drive the hoisting system or slewing platform,recycling kinetic and potential energy.The utilization of the kinetic and potential energy reduces the energy loss and installed power of the min-ing shovel.Meanwhile,the reliability of the mining shovel pure electric drive system also can be increased.In this paper,the hydraulic-electric hybrid driving principle is introduced,a small-scale testbed is set up to verify the feasibil-ity of the system,and a co-simulation model of the proposed system is established to clarify the system operation and energy characteristics.The test and simulation results show that,by adopting the proposed system,compared with the traditional purely electric driving system,the peak power and energy consumption of the hoisting electric motor are reduced by 36.7%and 29.7%,respectively.Similarly,the slewing electric motor experiences a significant decrease in peak power by 86.9%and a reduction in energy consumption by 59.4%.The proposed system expands the application area of the hydraulic electric hybrid drive system and provides a reference for its application in over-sized and super heavy equipment.
基金Supported by Henan Province Science and Technology Key Project of China(Grant Nos.202102210081,202102210082)Fundamental Research Funds for Henan Province Colleges and Universities of China(Grant No.NSFRF140120)Doctor Foundation of Henan Polytechnic University(Grant No.B2012-101).
文摘When saving energy in a pneumatic system,the problem of energy losses is usually solved by reducing the air supply pressure.The power-matching method is applied to optimize the air-supply pressure of the pneumatic system,and the energy-saving effect is verified by experiments.First,the experimental platform of a pneumatic rotary actuator servo-control system is built,and the mechanism of the valve-controlled cylinder system is analyzed.Then,the output power characteristics and load characteristics of the system are derived,and their characteristic curves are drawn.The employed air compressor is considered as a constant-pressure source of a quantitative pump,and the power characteristic of the system is matched.The power source characteristic curve should envelope the output characteristic curve and load characteristic curve.The minimum gas supply pressure obtained by power matching represents the optimal gas supply pressure.The comparative experiments under two different gas supply pressure conditions show that the system under the optimal gas supply pressure can greatly reduce energy losses.
基金This work was financially supported by the Key Technologies R&D Program of Tianjin(No.06YFGZGX02400).
文摘Copper-zinc alloy element for boiler energy saving was put in the intake of simulated boiler system to investigate the interaction and transfer of ions in water system both theoretically and experimentally.The fouling was analyzed by scanning electron microscopy(SEM)and energy dispersive X-ray detector(EDX).The results show that the transfer of calcium and magnesium ions in heat-transfer-surface-water system is affected by zinc ions dissolved from the alloy because of primary battery reaction.Some calcium ions of calcium carbonate crystal are replaced by zinc ions,the growth of aragonite crystal nucleus is retarded,and the transition of calcium carbonate from aragonite to calcite is hampered.