Experiments on grouting-reinforced rock mass specimens with different particle sizes and features were carried out in this study to examine the effects of grouting reinforcement on the load-bearing characteristics of ...Experiments on grouting-reinforced rock mass specimens with different particle sizes and features were carried out in this study to examine the effects of grouting reinforcement on the load-bearing characteristics of fractured rock mass.The strength and deformation features of grouting-reinforced rock mass were analyzed under different loading manners;the energy evolution mechanism of grouting-reinforced rock mass specimens with different particle sizes and features was investigated;the energy dissipation ratio and post-peak stress decreasing rate were employed to evaluate the bearing stability of grouting-reinforced rock mass.The results show that the strength and ductility of granite-reinforced rock mass(GRM)under biaxial loading are higher than that of sandstone-reinforced rock mass(SRM)under uniaxial loading.Besides,the energy evolution characteristics of grouting-reinforced rock mass under uniaxial and biaxial loading mainly could be divided into early,middle,and late stages.In the early stage,total,elastic,and dissipation energies were quite small with flatter curves;in the middle stage,elastic energy increased rapidly,whereas dissipation energy increased slowly;in the late stage,dissipation energy increased sharply.The energy dissipation ratio was used to represent the pre-peak plastic deformation.Under uniaxial loading,this ratio increased as the particle size increased and the pre-peak plastic deformation of grouting-reinforced rock mass became larger;under biaxial loading,it dropped as the particle size increased,and the pre-peak plastic deformation of grouting-reinforced rock mass became smaller.The post-peak stress decline rate A_(v) was used to assess the post-peak bearing performance of grouting-reinforced rock mass.Under uniaxial loading,parameter A_(v) exhibited reduction as the particle size kept increasing,and the ability of post-peak of grouting-reinforced rock mass to allow deformation development was greater,and the bearing capacity was greater;under biaxial loading,A_(v) increased with the particle size,and the ability of post-peak of grouting-reinforced rock mass to allow deformation development was low and the bearing capacity was reduced.The findings are considered instrumental in improving the stability of the roadway-surrounding rock by granite and sandstone grouting.展开更多
Denim is widely accepted among exported textile products due to its aesthetics, appearance, and fashion. Practitioners employed several physical or chemical treatments to improve denim qualities in denim finishing ope...Denim is widely accepted among exported textile products due to its aesthetics, appearance, and fashion. Practitioners employed several physical or chemical treatments to improve denim qualities in denim finishing operations. So, several treatment processes, including enzymatic, bleaching, singeing, heat set, and ozone finish, are used, which made this processing more energy consumption and time-consuming. Therefore, it is significant to investigate how changing the chemicals and raw ingredients could improve the finishing process, which is environmentally and economically beneficial for sustainable production practices in the denim finishing process. This study’s research design comprises an experimental investigation in a denim plant in Bangladesh. Two different fabrics were chosen to analyze, determining the potential savings of finishing on the denim fabrics’ performance characteristics. By deducting singeing and heat-set processes, the researchers ran an experimental process by maintaining the same length of fabric. Then, the impacts of finishing process optimization on the mechanical, thermal, and comfort parameters of drape, stiffness, and tear strength were examined. The study’s findings demonstrated that this experiment increased productivity and reduced the finishing unit’s energy consumption without compromising the denim fabrics’ quality. This study significantly impacts environmental sustainability by preserving limited energy resources and manufacturing denim finishing processes.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
Purpose–To address the problem that the current train operation mode that train selects one of several offline pre-generated control schemes before the departure and operates following the scheme after the departure,...Purpose–To address the problem that the current train operation mode that train selects one of several offline pre-generated control schemes before the departure and operates following the scheme after the departure,energy-saving performance of the whole metro system cannot be guaranteed.Design/methodology/approach–A cooperative train control framework is formulated to regulate a novel train operation mode.The classic train four-phase control strategy is improved for generating specific energy-efficient control schemes for each train.An improved brute force(BF)algorithm with a two-layer searching idea is designed to solve the optimisation model of energy-efficient train control schemes.Findings–Case studies on the actual metro line in Guangzhou,China verify the effectiveness of the proposed train control methods compared with four-phase control strategy under different kinds of train operation scenarios and calculation parameters.The verification on the computation efficiency as well as accuracy of the proposed algorithm indicates that it meets the requirement of online optimisation.Originality/value–Most existing studies optimised energy-efficient train timetable or train control strategies through an offline process,which has a defect in coping with the disturbance or delays effectively and promptly during real-time train operation.This paper studies an online optimisation of cooperative train control based on the rolling optimisation idea,where energy-efficient train operation can be realised once train running time is determined,thus mitigating the impact of unpredictable operation situations on the energy-saving performance of trains.展开更多
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
Currently,energy saving design has been conducted on single building but not on the whole residential community in urban and rural areas.So,the paper has proposed energy saving measures for residential planning from t...Currently,energy saving design has been conducted on single building but not on the whole residential community in urban and rural areas.So,the paper has proposed energy saving measures for residential planning from the perspective of site selection and layout of buildings.Specific measures are as follows.Firstly,buildings should be constructed on the sunny side and leeside;secondly,buildings on the south should be lower than those on the north;the east side of the building should be open while the west side should be closed;thirdly,climate protection unit should be set;fourthly,buildings should be of northsouth direction primarily,and the main room should be set on the east side and the assistant rooms or passage on the west side in the buildings of east-west direction;fifthly,it should select compact and wellarranged households and the units should not be combined in point and dislocation and jointing.展开更多
In order to have an in-depth understanding of the metal ceiling radiant panel with capillary tubes, a radiant ceiling heating system is constructed to study the actual heating performance and thermal comfort by experi...In order to have an in-depth understanding of the metal ceiling radiant panel with capillary tubes, a radiant ceiling heating system is constructed to study the actual heating performance and thermal comfort by experiments. In addition, the energy saving potential of the novel heating system is discussed in terms of the COP （coefficient of performance） of the ground source heat pump and the exergy efficiency of the radiant terminal. The results indicate that the heating system shows high thermal stability and thermal comfort. When the system reaches a stable condition, the radiant heat transfer accounts for 62.7% of the total heat transfer, and the total heat transfer can meet the heating demands of most buildings. Compared to a radiant floor heating system, it offers advantages in a shorter preheating time, a lower supply water temperature and a stronger heating capability. The COP of the ground source heat pump is increased greatly when the supply water temperature is 28 to 33 ℃, and the exergy efficiency of the metal ceiling with capillary tubes is 1.6 times that of the radiant floor when the reference temperature is 5 ℃ The novel radiant ceiling heating system shows a tremendous energy saving potential.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
The artificial ground freezing(AGF)systems are designed to operate continuously for an extended period of time to control the groundwater seepage and to strengthen the groundwater structure surrounding excavation area...The artificial ground freezing(AGF)systems are designed to operate continuously for an extended period of time to control the groundwater seepage and to strengthen the groundwater structure surrounding excavation areas.This mode of operation requires a massive amount of energy to sustain the thickness of the frozen body.Therefore,it is of great interest to propose new concepts to reduce energy consumption while providing sufficient structural stability and safe operation.This paper discusses the principle of the freezing on demand(FoD)by means of experiment and mathematical model.A lab-scale rig that mimics the AGF process is conceived and developed.The setup is equipped with more than 80 thermocouples,flow-meters,and advanced instrumentation system to analyze the performance of the AGF process under the FoD concept.A mathematical model has been derived,validated,and utilized to simulate the transient FoD concept.The results suggest that the overall energy saving notably depends on the coolant’s temperature;the energy saving increases while decreasing the coolant inlet temperature.Moreover,applying the FoD concept in an AGF system leads to a significant drop in energy consumption.展开更多
To improve ground vehicle efficiency, shift schedule energy saving was proposed for the ground vehicle automatic transmission by studying the function of the torque converter and transmission in the vehicular drivetra...To improve ground vehicle efficiency, shift schedule energy saving was proposed for the ground vehicle automatic transmission by studying the function of the torque converter and transmission in the vehicular drivetrain. The shift schedule can keep the torque converter working in the high efficiency range under all the working conditions except in the low efficiency range on the left when the transmission worked at the lowest shift, and in the low efficiency range on the right when the transmission worked at the highest shift. The shift quality key factors were analysed. The automatic trans-mission's bench-test adopting this shift schedule was made on the automatic transmission's test-bed. The experimental results showed that the shift schedule was correct and that the shift quality was controllable.展开更多
In order to save energy and make more efficient use of wireless channel, this article puts forward an energy saving cooperative relaying scheme which actuates the cooperative transmis- sion only when the feedback from...In order to save energy and make more efficient use of wireless channel, this article puts forward an energy saving cooperative relaying scheme which actuates the cooperative transmis- sion only when the feedback from the destination indicates failure of the direct transmission. The proposed scheme selects the optimal relay and its corresponding transmission power in each time slot based on channel condition and residual ener- gy with the objective of minimizing energy con- sumption and extending network lifetime. In the study, the f＇mite-state Markov channel model is used to characterize the correlation structure of channel fading in wireless networks, and the pro- cedure of relay selection and transmission power decision is formulated as a M arkov decision process. Numerical and simulation results show that the proposed scheme consumes less energy and prolongs the network lifetime.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
Internal thermally coupled distillation columns (ITCDIC) are the frontier of distillation energy saving research. In this paper, a novel energy saving model of ideal ITCDIC and a simulation algorithm are presented,upo...Internal thermally coupled distillation columns (ITCDIC) are the frontier of distillation energy saving research. In this paper, a novel energy saving model of ideal ITCDIC and a simulation algorithm are presented,upon which a series of comparative studies on energy savings with conventional distillation columns are carried out. Furthermore, we present an optimization model of ideal ITCDIC, which can be used to achieve the maximum energy saving and find the optimal design parameters directly. The binary system of benzene-toluene is adopted for the illustrative example of simulation and optimization. The results show that the maximum energy saving of ITCDIC is 52.25% (compared with energy consumption of conventional distillation under the minimum reflux ratio operation); the optimal design parameters are obtained, where the rectifying section pressure and the feed thermal condition are Pr=0.3006 MPa and q=0.5107 respectively.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
This article sums up the energy consumption of process units and the overall energy consumption of 10 Mt/a class refineries constructed or revamped in recent years. The energy saving measures adopted in design of thes...This article sums up the energy consumption of process units and the overall energy consumption of 10 Mt/a class refineries constructed or revamped in recent years. The energy saving measures adopted in design of these refineries are analyzed and discussed. Finally, this article also makes comments and puts forward recommendations on the objectives for energy conservation at refineries in the future.展开更多
基金Project(2023YFC2907600)supported by the National Key Research and Development Program of ChinaProject(202203a07020011)supported by the Major Science and Technology Projects of Anhui Province,China+4 种基金Project(T2021137)supported by the National Talent Project,ChinaProject(T000508)supported by the Leading Talent Project of the Special Support Plan of Anhui Province,ChinaProject(GXXT-2021-075)supported by the University Synergy Innovation Program of Anhui Province,ChinaProject(2022AH010053)supported by the Excellent Scientific Research and Innovation Team of Universities in Anhui Province,ChinaProject(2022CX1004)supported by the Anhui University of Science and Technology Postgraduate Innovation Fund Project,China。
文摘Experiments on grouting-reinforced rock mass specimens with different particle sizes and features were carried out in this study to examine the effects of grouting reinforcement on the load-bearing characteristics of fractured rock mass.The strength and deformation features of grouting-reinforced rock mass were analyzed under different loading manners;the energy evolution mechanism of grouting-reinforced rock mass specimens with different particle sizes and features was investigated;the energy dissipation ratio and post-peak stress decreasing rate were employed to evaluate the bearing stability of grouting-reinforced rock mass.The results show that the strength and ductility of granite-reinforced rock mass(GRM)under biaxial loading are higher than that of sandstone-reinforced rock mass(SRM)under uniaxial loading.Besides,the energy evolution characteristics of grouting-reinforced rock mass under uniaxial and biaxial loading mainly could be divided into early,middle,and late stages.In the early stage,total,elastic,and dissipation energies were quite small with flatter curves;in the middle stage,elastic energy increased rapidly,whereas dissipation energy increased slowly;in the late stage,dissipation energy increased sharply.The energy dissipation ratio was used to represent the pre-peak plastic deformation.Under uniaxial loading,this ratio increased as the particle size increased and the pre-peak plastic deformation of grouting-reinforced rock mass became larger;under biaxial loading,it dropped as the particle size increased,and the pre-peak plastic deformation of grouting-reinforced rock mass became smaller.The post-peak stress decline rate A_(v) was used to assess the post-peak bearing performance of grouting-reinforced rock mass.Under uniaxial loading,parameter A_(v) exhibited reduction as the particle size kept increasing,and the ability of post-peak of grouting-reinforced rock mass to allow deformation development was greater,and the bearing capacity was greater;under biaxial loading,A_(v) increased with the particle size,and the ability of post-peak of grouting-reinforced rock mass to allow deformation development was low and the bearing capacity was reduced.The findings are considered instrumental in improving the stability of the roadway-surrounding rock by granite and sandstone grouting.
文摘Denim is widely accepted among exported textile products due to its aesthetics, appearance, and fashion. Practitioners employed several physical or chemical treatments to improve denim qualities in denim finishing operations. So, several treatment processes, including enzymatic, bleaching, singeing, heat set, and ozone finish, are used, which made this processing more energy consumption and time-consuming. Therefore, it is significant to investigate how changing the chemicals and raw ingredients could improve the finishing process, which is environmentally and economically beneficial for sustainable production practices in the denim finishing process. This study’s research design comprises an experimental investigation in a denim plant in Bangladesh. Two different fabrics were chosen to analyze, determining the potential savings of finishing on the denim fabrics’ performance characteristics. By deducting singeing and heat-set processes, the researchers ran an experimental process by maintaining the same length of fabric. Then, the impacts of finishing process optimization on the mechanical, thermal, and comfort parameters of drape, stiffness, and tear strength were examined. The study’s findings demonstrated that this experiment increased productivity and reduced the finishing unit’s energy consumption without compromising the denim fabrics’ quality. This study significantly impacts environmental sustainability by preserving limited energy resources and manufacturing denim finishing processes.
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%.
基金This research was supported by the National Natural Science Foundation of China(Grant No.71971016).On behalf of all co-authors,the corresponding author states that there is no conflict of interest.
文摘Purpose–To address the problem that the current train operation mode that train selects one of several offline pre-generated control schemes before the departure and operates following the scheme after the departure,energy-saving performance of the whole metro system cannot be guaranteed.Design/methodology/approach–A cooperative train control framework is formulated to regulate a novel train operation mode.The classic train four-phase control strategy is improved for generating specific energy-efficient control schemes for each train.An improved brute force(BF)algorithm with a two-layer searching idea is designed to solve the optimisation model of energy-efficient train control schemes.Findings–Case studies on the actual metro line in Guangzhou,China verify the effectiveness of the proposed train control methods compared with four-phase control strategy under different kinds of train operation scenarios and calculation parameters.The verification on the computation efficiency as well as accuracy of the proposed algorithm indicates that it meets the requirement of online optimisation.Originality/value–Most existing studies optimised energy-efficient train timetable or train control strategies through an offline process,which has a defect in coping with the disturbance or delays effectively and promptly during real-time train operation.This paper studies an online optimisation of cooperative train control based on the rolling optimisation idea,where energy-efficient train operation can be realised once train running time is determined,thus mitigating the impact of unpredictable operation situations on the energy-saving performance of trains.
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.
文摘Currently,energy saving design has been conducted on single building but not on the whole residential community in urban and rural areas.So,the paper has proposed energy saving measures for residential planning from the perspective of site selection and layout of buildings.Specific measures are as follows.Firstly,buildings should be constructed on the sunny side and leeside;secondly,buildings on the south should be lower than those on the north;the east side of the building should be open while the west side should be closed;thirdly,climate protection unit should be set;fourthly,buildings should be of northsouth direction primarily,and the main room should be set on the east side and the assistant rooms or passage on the west side in the buildings of east-west direction;fifthly,it should select compact and wellarranged households and the units should not be combined in point and dislocation and jointing.
基金The National Natural Science Foundation of China(No.51106023)the National Key Technology R&D Program during the12th Five-Year Plan Period(No.2011BAJ03B14)
文摘In order to have an in-depth understanding of the metal ceiling radiant panel with capillary tubes, a radiant ceiling heating system is constructed to study the actual heating performance and thermal comfort by experiments. In addition, the energy saving potential of the novel heating system is discussed in terms of the COP （coefficient of performance） of the ground source heat pump and the exergy efficiency of the radiant terminal. The results indicate that the heating system shows high thermal stability and thermal comfort. When the system reaches a stable condition, the radiant heat transfer accounts for 62.7% of the total heat transfer, and the total heat transfer can meet the heating demands of most buildings. Compared to a radiant floor heating system, it offers advantages in a shorter preheating time, a lower supply water temperature and a stronger heating capability. The COP of the ground source heat pump is increased greatly when the supply water temperature is 28 to 33 ℃, and the exergy efficiency of the metal ceiling with capillary tubes is 1.6 times that of the radiant floor when the reference temperature is 5 ℃ The novel radiant ceiling heating system shows a tremendous energy saving potential.
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.
基金McGill Engineering Doctoral Award(MEDA)Fonds de recherche du Québec-Nature et technologies(FRQNT)-Bourses de doctorat(B2X)for supporting this research
文摘The artificial ground freezing(AGF)systems are designed to operate continuously for an extended period of time to control the groundwater seepage and to strengthen the groundwater structure surrounding excavation areas.This mode of operation requires a massive amount of energy to sustain the thickness of the frozen body.Therefore,it is of great interest to propose new concepts to reduce energy consumption while providing sufficient structural stability and safe operation.This paper discusses the principle of the freezing on demand(FoD)by means of experiment and mathematical model.A lab-scale rig that mimics the AGF process is conceived and developed.The setup is equipped with more than 80 thermocouples,flow-meters,and advanced instrumentation system to analyze the performance of the AGF process under the FoD concept.A mathematical model has been derived,validated,and utilized to simulate the transient FoD concept.The results suggest that the overall energy saving notably depends on the coolant’s temperature;the energy saving increases while decreasing the coolant inlet temperature.Moreover,applying the FoD concept in an AGF system leads to a significant drop in energy consumption.
文摘To improve ground vehicle efficiency, shift schedule energy saving was proposed for the ground vehicle automatic transmission by studying the function of the torque converter and transmission in the vehicular drivetrain. The shift schedule can keep the torque converter working in the high efficiency range under all the working conditions except in the low efficiency range on the left when the transmission worked at the lowest shift, and in the low efficiency range on the right when the transmission worked at the highest shift. The shift quality key factors were analysed. The automatic trans-mission's bench-test adopting this shift schedule was made on the automatic transmission's test-bed. The experimental results showed that the shift schedule was correct and that the shift quality was controllable.
基金The authors would like to thank the reviewers for their de-tailed reviews and constructive comments, which have helped improve the quality of this paper. This work was supported by the National Natural Science Foundation of China under Grant No. 61101107 the Scientific Research and Innovation Plan for the Youth of BUPT under Grant No. 2011RC0305 the National International Science and Technology Cooperation Project under Grant No. 2010DFA11320.
文摘In order to save energy and make more efficient use of wireless channel, this article puts forward an energy saving cooperative relaying scheme which actuates the cooperative transmis- sion only when the feedback from the destination indicates failure of the direct transmission. The proposed scheme selects the optimal relay and its corresponding transmission power in each time slot based on channel condition and residual ener- gy with the objective of minimizing energy con- sumption and extending network lifetime. In the study, the f＇mite-state Markov channel model is used to characterize the correlation structure of channel fading in wireless networks, and the pro- cedure of relay selection and transmission power decision is formulated as a M arkov decision process. Numerical and simulation results show that the proposed scheme consumes less energy and prolongs the network lifetime.
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Supported by the National Environmental Protection Bureau of P.R.China(Huan-Ke-Ke,1997,No.006,Project 14),China-Japan cooperative project:"Research on energy savings and alleviating environmental burden in petroleum enterprises"of Institute of Industrial
文摘Internal thermally coupled distillation columns (ITCDIC) are the frontier of distillation energy saving research. In this paper, a novel energy saving model of ideal ITCDIC and a simulation algorithm are presented,upon which a series of comparative studies on energy savings with conventional distillation columns are carried out. Furthermore, we present an optimization model of ideal ITCDIC, which can be used to achieve the maximum energy saving and find the optimal design parameters directly. The binary system of benzene-toluene is adopted for the illustrative example of simulation and optimization. The results show that the maximum energy saving of ITCDIC is 52.25% (compared with energy consumption of conventional distillation under the minimum reflux ratio operation); the optimal design parameters are obtained, where the rectifying section pressure and the feed thermal condition are Pr=0.3006 MPa and q=0.5107 respectively.
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.
文摘This article sums up the energy consumption of process units and the overall energy consumption of 10 Mt/a class refineries constructed or revamped in recent years. The energy saving measures adopted in design of these refineries are analyzed and discussed. Finally, this article also makes comments and puts forward recommendations on the objectives for energy conservation at refineries in the future.
