In contrast to a traditional coal-fired power generation plant where steam extracted from a turbine is used to preheat the feedwater in all preheating stages, a solar-aided power generation(SAPG) plant uses solar heat...In contrast to a traditional coal-fired power generation plant where steam extracted from a turbine is used to preheat the feedwater in all preheating stages, a solar-aided power generation(SAPG) plant uses solar heat to replace a part or all of the extracted steam in one or more preheating stages. The performance of an SAPG plant with different replacements is investigated in this study by using specific consumption theory(SCT). Fuel-specific and cost-specific consumption models for SAPG plants are built based on the SCT. A typical 330 MW coal-fired power plant is used as the study case. The performance of the SAPG plant in terms of specific consumption, with steam obtained from the first through the eighth(except for the fourth) stages of extraction replaced by solar heat, is compared with that of the reference coal-fired power plant. The fuel-specific consumption of the SAPG plant is determined to be lower than that of the reference coal-fired power plant. The fuel-specific consumption accrual distribution in SAPG plants is used to assess the effect of each individual replacement. Effective strategies to reduce the specific costs of the SAPG and coal-fired power plants are proposed based on the results of this study.展开更多
Coenzyme Q10(CoQ10)is the most consumed dietary supplement and mainly biosynthesized by aerobic fermentation of Rhodobacter sphaeroides(R.sphaeroides).Oxygen supply was identified as a bottleneck for improving CoQ10 y...Coenzyme Q10(CoQ10)is the most consumed dietary supplement and mainly biosynthesized by aerobic fermentation of Rhodobacter sphaeroides(R.sphaeroides).Oxygen supply was identified as a bottleneck for improving CoQ10 yield in R.sphaeroides.In this study,a precise regulation strategy based on dielectric spectroscopy(DS)was applied to further improve CoQ10 biosynthesis by R.sphaeroide.First,a quantitative response model among viable cells,cell morphology,and oxygen uptake rate(OUR)was established.DS could be used to detect viable R.sphaeroides cells,and the relationship among cell morphology,CoQ10 biosynthesis,and OUR was found to be significant.Based on this model,the online specific oxygen consumption rate(QO2)control strategy was successfully applied to the CoQ10 fermentation process.QO2 controlled at 0.07±0.01×10−7mmol/cell/h was most favorable for CoQ10 biosynthesis,resulting in a 28.3%increase in CoQ10 production.Based on the multi-parameters analysis and online QO2 control,a precise online nutrient feeding strategy was established using conductivity detected by DS.CoQ10 production was improved by 35%,reaching 3384 mg/L in 50 L bioreactors.This online control strategy would be effectively applied for improving industrial CoQ10 production,and the precise fermentation control strategy could also be applied to other fermentation process.展开更多
Theoretical minimum and actual specific energy consumptions （SEC） of typical manufacturing process （SMP） were studied. Firstly, a process division of a typical SMP in question was conducted with the theory of SEC ...Theoretical minimum and actual specific energy consumptions （SEC） of typical manufacturing process （SMP） were studied. Firstly, a process division of a typical SMP in question was conducted with the theory of SEC analysis. Secondly, an exergy analysis model of a subsystem consisting of several parallel processes and a SEC analysis model of SMP were developed. And finally, based on the analysis models, the SEC of SMP was analyzed by means of the statistical significance. The results show that the SEC of typical SMP comprises the theoretical minimum SEC and the additional SEC derived from the irreversibility~ and the SMP has a theoretical minimum SEC of 6.74 GJ/t and an additional SEC of 19.32 GJ/t, which account for 25.88% and 74.12% of the actual SEC, respectively.展开更多
This study investigates the application of an enhanced Back-Propagation(BP)neural network model for analyzing and predicting beef microwave drying processes.Based on Fick’s second law of diffusion,effective moisture ...This study investigates the application of an enhanced Back-Propagation(BP)neural network model for analyzing and predicting beef microwave drying processes.Based on Fick’s second law of diffusion,effective moisture diffusivity was determined under varying microwave power levels(70-420 W)and relative humidity conditions(0%,30%,50%).Experimental results revealed moisture diffusivity values ranging from 2.23×10^(–9) to 2.87×10^(–8 )m^(2)/s.A significant inverse relationship was observed between microwave power and specific energy consumption,with optimal energy efficiency(8.39 MJ/kg water)achieved at 420 W.A multi-layer BP neural network architecture was developed to model drying kinetics and energy consumption patterns,with subsequent optimization using Sparrow Search Algorithm(SSA)for weight and threshold parameter calibration.Comparative analysis demonstrated that the SSA-optimized BP neural network significantly outperformed both conventional BP models and genetic algorithm-optimized variants in predictive accuracy.The enhanced model exhibited robust performance in predicting moisture content evolution and energy consumption dynamics throughout the drying process.These findings provide valuable insights for developing energy-efficient industrial-scale beef drying systems while maintaining product quality.The proposed intelligent computing framework represents a promising approach for precise modeling,prediction,and optimization of microwave drying processes in food processing applications.展开更多
In some industrial plants, wastewater was intermittently or seasonally generated. There may be periods during which wastewater treatment facilities have to be set into an idle phase over several weeks. When wastewater...In some industrial plants, wastewater was intermittently or seasonally generated. There may be periods during which wastewater treatment facilities have to be set into an idle phase over several weeks. When wastewater was generated again, the activated sludge flocs may have disintegrated. In this experiment, re-activation characteristics of aerobic granular sludge starved for 2 months were investigated. Specific oxygen utilization rate(SOUR) was used as an indicator to evaluate the metabolic activity of the sludge. The results revealed that aerobic granular sludge could be stored up to two months without running the risk of losing the integrity of the granules and metabolic potentials. The apparent color of aerobic granules stored at room temperature gradually turned from brownish-yellowish to gray brown. They appeared brownish-yellowish again 2 weeks after re-activation. The velocity and strength of granules after 2-month idle period could be fully restored about 3 weeks after re-activation. Metabolic activity, however, dropped to 15 8 mg O_2/(g MLVSS·h), i.e. 74 % reduction after 2 months of storage. After restarting the reactor, it took 2 weeks that SOUR of up to 48 5 mg O_2 /(g MLVSS·h) was achieved. A stable effluent COD concentration of less than 150 mg/L was achieved during the re-activation process.展开更多
To improve the rock breaking ability, cavitating waterjet and abrasive waterjet are combined by using a coaxial low-speed waterjet generated around the periphery of a high-speed abrasive waterjet, and a new type of wa...To improve the rock breaking ability, cavitating waterjet and abrasive waterjet are combined by using a coaxial low-speed waterjet generated around the periphery of a high-speed abrasive waterjet, and a new type of waterjet called unsubmerged cavitating abrasive waterjet(UCAWJ) is thus produced. The rock breaking performance of UCAWJ was compared with submerged cavitating abrasive waterjet(SCAWJ)and unsubmerged abrasive waterjet(UAWJ) by impinging sandstone specimens. Moreover, the effects of jet pressure, standoff distance, abrasive flow rate and concentration were studied by evaluating the specific energy consumption, and the area, depth, and mass loss of the eroded specimen. The results show that the artificially generated submerged environment in UCAWJ is able to enhance the rock breaking performance under the same operating parameters. Furthermore, the rock breaking performance of UCAWJ is much better at higher jet pressures and smaller standoff distances when compared with UAWJ. The greatest rock breaking ability of UCAWJ appears at jet pressure of 50 MPa and standoff distance of 32 mm, with the mass loss of sandstone increased by 370.6% and the energy dissipation decreased by 75.8%. In addition, under the experimental conditions the optimal abrasive flow rate and concentration are 76.5 m L/min and 3%, respectively.展开更多
Slurry pipeline transport is widely used in several industrial processes.Calculating the specific power consumption(SPC)and determining the best working conditions are important for the design and operation of transpo...Slurry pipeline transport is widely used in several industrial processes.Calculating the specific power consumption(SPC)and determining the best working conditions are important for the design and operation of transportation systems.Based on the Shanghai Jiao Tong University high-concentration multi-sized slurry pressure drop(SJTU-HMSPD)pipeline-resistance-calculation model,the SJTU-SPC model for calculating the power required to transport a unit volume of solid materials over a unit pipeline length is established for a slurry transport system.The said system demonstrates a uniformity coefficient in the 1.26–7.98 range,median particle size of 0.075–4 mm,particle volume concentration of 10–60%,and pipeline diameter of 0.203–0.8 m.The results obtained were successfully verified against existing experimental data.The influence of parameters,such as particle-gradation uniformity coefficient,median particle size,pipe diameter,and particle volume concentration,on the SPC were analysed.The results revealed that the greater is the uniformity coefficient,the smaller is the minimum specific energy consumption and the larger the optimal transport concentration for a constant,median particle size slurry.As observed,the optimal transport concentration for broad-graded sand equalled approximately 48%.These results supplement the conclusions of existing research,indicating that the optimal transport concentration is approximately 30%and provides theoretical support for high concentration transportation of broad graded slurry.展开更多
Under the condition of the designated collection ratio and the interfused ratio of mullock, to ensure the least energy consumption, the parameters of collecting head （the feed speed, the axes height of collecting hea...Under the condition of the designated collection ratio and the interfused ratio of mullock, to ensure the least energy consumption, the parameters of collecting head （the feed speed, the axes height of collecting head, and the rotate speed） are chosen as the optimized parameters. According to the force on the cutting pick, the collecting size of the cobalt crust and bedrock and the optimized energy consumption of the collecting head, the optimized design model of collecting head is built. Taking two hundred groups seabed microtopography for grand in the range of depth displacement from 4.5 to 5.5 era, then making use of the improved simulated annealing genetic algorithm （SAGA）, the corresponding optimized result can be obtained. At the same time, in order to speed up the controlling of collecting head, the optimization results are analyzed using the regression analysis method, and the conclusion of the second parameter of the seabed microtopography is drawn.展开更多
Many industrial products made from fossil fuels cause the problems of global warming,depletion of fossil fuel resources and decrease of the land by landfill.In this report,the amounts of CO2 emissions as the environme...Many industrial products made from fossil fuels cause the problems of global warming,depletion of fossil fuel resources and decrease of the land by landfill.In this report,the amounts of CO2 emissions as the environmental load and the specific energy consumptions as the depletion of fossil fuel resources of biodegradable plastics and conventional plastic as food trays are compared using life cycle assessment methodology.The amount of CO2 emission of PHB(poly(3-hydroxybutyrate-co-4-hydroxybutyrate)) tray was the smallest among those of trays of other plastics.The specific energy consumption of SPCL(starch/polycaprolactone) was the smallest among those of trays of other plastics.It clearly reveals that the utilization of the biodegradable plastics is an effective way of alternatives of the conventional plastics.展开更多
This study presents hybrid clones of Corymbia spp.developed by Aperam BioEnergia as potential substitutes for Eucalyptus wood in the pulp industry.The biomass of Eucalyptus spp.was compared with that of Corymbia spp.b...This study presents hybrid clones of Corymbia spp.developed by Aperam BioEnergia as potential substitutes for Eucalyptus wood in the pulp industry.The biomass of Eucalyptus spp.was compared with that of Corymbia spp.by performing modified kraft pulping and basic density analyses.Comparisons were made by analyzing their respective mean annual increments of cellulose(MAI_(cel))and specific wood consumption(SWC),estimated using a kappa number of(19±1).The results showed that one of the hybrid clones(Corymbia citriodora×Corymbia torelliana,ID 4)had higher basic wood density,higher screened yield,better MAI_(cel#k19),and lower SWC than the other samples,reaching values of 0.608 t/m^(3),54.1%,24.6 ADt/ha/year(i.e.,air dry ton/hectare/year),and 2.74 m^(3)/ADt,respectively.Consequently,clone ID 4 had the highest MAI_(cel)/SWC ratio score(8.98).Given its high forest productivity and low industrial cost compared with other samples,as well as its advantages over Eucalyptus spp.wood,we concluded that clone ID 4 has great potential as an alternative biomass for pulp production.展开更多
The authors studied diesel combustion improvement with a reformed fuel that mixed nano air-bubbles by using an EMNB （ejector-type micro-nano bubbler）. The EMNB performs adequately and is smaller （20 mm diameter, 34...The authors studied diesel combustion improvement with a reformed fuel that mixed nano air-bubbles by using an EMNB （ejector-type micro-nano bubbler）. The EMNB performs adequately and is smaller （20 mm diameter, 34 mm length） than other micro-nano bubblers. It is quite possible to install it in an actual engine. An experiment was performed using a single cylinder engine with a dish or square shaped combustion chamber cavity, and in order to compare the engine speed change, we also used a four cylinder engine with a turbo-charger. The results showed that an improvement in specific fuel consumption, a decrease in the density of the exhaust smoke and an improvement in charging efficiency etc. were achieved by mixing nano bubbles into gas oil under most conditions. It is confirmed that combustion was promoted and improved by a physical and chemical action through mixing the nano bubbles into gas oil.展开更多
The price of fuel oil continues to rise, decreased supplies oil at the other side, both factors increase the interest of researchers to conduct research related to fuel efficiency. Therefore the aim of this study is t...The price of fuel oil continues to rise, decreased supplies oil at the other side, both factors increase the interest of researchers to conduct research related to fuel efficiency. Therefore the aim of this study is to improve the efficiency fuel of diesel engine using fuel filter. The method used for the research is testing the most efficient fuel filters made of coil wire coil winding 5,000, the three distinguished from the coil core diameter of 44.5, 28.5 and 17.5 mm in diesel engine. The performance test was conducted from 1,100 rpm to 1,700 rpm, the throttle opening of 30%-60%. The first testing was done by creating a constant speed 1,500 rpm and throttle opening varies from 30% to 60%, further testing is done by varying the rpm start from 1,100 rpm to 1,700 rpm to make constant valve 40% and 60%.展开更多
The research presents an improved method of rational design of energy-efficient low-rise residential buildings according to their life cycle. The mathematical model for finding the optimal version of draft power-effic...The research presents an improved method of rational design of energy-efficient low-rise residential buildings according to their life cycle. The mathematical model for finding the optimal version of draft power-efficient residential building has been developed. For conditions of Ukraine the optimization problem has been set and solved （finding the optimal version of the draft energy-efficient buildings）. The calculations prove the fact that the construction of passive houses in Ukraine today is economically feasible. Scientific and practical regulations, outlined in the research, can be used by all participants of the investment programs, and energy-efficiency projects, renovation projects and developing normative-technical documents.展开更多
The water quality and energy consumption of wastewater treatment plants(WWTPs)in Taihu Basin were evaluated on the basis of the operation data from 204 municipal WWTPs in the basin by using various statistical methods...The water quality and energy consumption of wastewater treatment plants(WWTPs)in Taihu Basin were evaluated on the basis of the operation data from 204 municipal WWTPs in the basin by using various statistical methods.The influent ammonia nitrogen(NH3-N)and total nitrogen(TN)of WWTPs in Taihu Basin showed normal distribution,whereas chemical oxygen demand(COD),biochemical oxygen demand(BOD5),suspended solid(SS),and total phosphorus(TP)showed positively skewed distribution.The influent BOD5/COD was 0.4%-0.6%,only 39.2%SS/BOD5 exceeded the standard by 36.3%,the average BOD5/TN was 3.82,and the probability of influent BOD5/TP>20 was 82.8%.The average energy consumption of WWTPs in Taihu Basin in 2017 was 0.458 kWh/m^3.The specific energy consumption of WWTPs with a daily treatment capacity of more than 5×10^4 m^3 in Taihu Basin was stable at 0.33 kWh/m^3.A power function relationship was observed between the reduction in COD and NH3-N and the specific energy consumption of pollutant reduction,and the higher the pollutant reduction is,the lower the specific energy consumption of pollutant reduction presents.In addition,a linear relationship existed between the energy consumption of WWTPs and the specific energy consumption of influent volume and pollutant reduction.Therefore,upgrading and operation with less energy consumption of WWTPs is imperative and the suggestions for Taihu WWTPs based on stringent discharge standard are proposed in detail.展开更多
Agriculture is the largest consumer of freshwater.Desalinated seawater is an important alternative water source for sustainable irrigation.However,some issues of the current desalination technology hinder its use for ...Agriculture is the largest consumer of freshwater.Desalinated seawater is an important alternative water source for sustainable irrigation.However,some issues of the current desalination technology hinder its use for agriculture irrigation,including low boron removal and high energy consumption.This study systematically explored the feasibility of employing fertilizer drawn forward osmosis(FDFO)as an alternative to 2nd pass reverse osmosis(RO)by considering the boron removal performance and specific energy consumption(SEC).Different operating conditions were investigated,such as the boron and NaCl concentrations in feed solution(FS),draw solution(DS)concentration,pH,the volume ratio of FS to DS,membrane orientation,flow rate,and operating temperature.The results indicated that a low boron concentration in FS and high DS pH(pH=11.0)decreased the boron solute flux,and led to low final boron concentration in the DS.The other operating conditions had negligible influence on the final DS boron concentration.Also,a lower flow rate and higher specific water flux with certain permeate water volumes were conducive to reducing the SEC of the FDFO process.Overall,our study paves a new way of using FDFO in irrigation,which avoids the phytotoxicity and human health risk of boron.The results show the potential of FDFO as an alternative to 2nd pass RO for irrigation water production.展开更多
To investigate the influence of ultrasound pretreatment on sludge anaerobic digestion,the ultrasound disintegration of residual sludge in water treatment of petrochemical plant was studied,and the mechanisms of ultras...To investigate the influence of ultrasound pretreatment on sludge anaerobic digestion,the ultrasound disintegration of residual sludge in water treatment of petrochemical plant was studied,and the mechanisms of ultrasound and medium were introduced.Experimental results indicate that ultrasound cavitation induces the rise of sludge temperature,which improves ultrasound disintegra-tion on sludge.U1trasound pretreatment can advance observ-ably the quantity of chemical oxygen demand in sludge supernatant fluid(SCOD),which increases with ultrasound intensity and sonication time.The degree of ultrasound disintegration increases with the specific energy input.When the specific energy input is l0000 kJ/kg of total dry solids,the degree of ultrasonic sludge disintegration reaches 40%.展开更多
Energy conservation in heating systems has great influence on overall sustainable development strategy. Heating technology, especially combined heat and power(CHP, cogeneration), has been attracting increased interest...Energy conservation in heating systems has great influence on overall sustainable development strategy. Heating technology, especially combined heat and power(CHP, cogeneration), has been attracting increased interest and rapidly developing in recent years. However, the theoretical potential of heating from the perspective of thermodynamics has not been clearly illustrated. This paper presents a theoretical analysis of heating systems based on the 1st and 2nd laws of thermodynamics using the specific fuel consumption(SFC) analysis method, clarifies the theoretical potential limitation of heating systems and illustrates the process of reversible heating on the basis of the total energy system. A novel concept(green heating, GH) and a new indicator(green-heating index, GH Index) are scientifically defined to characterise different options for heating and to quantitatively evaluate their fuel consumption levels. Thereafter, the fuel consumptions of four typical space heating modes are compared and discussed to present the application of GH theory and validate the power of the proposed concept and index. Furthermore, two different CHP technologies are analyzed with an instantiation case, and a novel CHP system is recommended, which may scientifically support the development of heating technology and further improve the processes of energy-saving and CO2 reduction.展开更多
The energy-saving analytics of coal-fired power units in China is confronting new challenges especially with even more complicated system structure, higher working medium parameters, time-dependent varying operation c...The energy-saving analytics of coal-fired power units in China is confronting new challenges especially with even more complicated system structure, higher working medium parameters, time-dependent varying operation conditions and boundaries such as load rate, coal quality, ambient temperature and humidity. Compared with the traditional optimization of specific operating parameters, the idea of the energy-consumption benchmark state was proposed. The equivalent specific fuel consumption(ESFC) analytics was introduced to determine the energy-consumption benchmark state, with the minimum ESFC under varying operation boundaries. Models for the energy-consumption benchmark state were established, and the endogenous additional specific consumption(ASFC) and exogenous ASFC were calculated. By comparing the benchmark state with the actual state, the energy-saving tempospacial effect can be quantified. As a case study, the energy consumption model of a 1000 MW ultra supercritical power unit was built. The results show that system energy consumption can be mainly reduced by improving the performance of turbine subsystem. This nearly doubles the resultant by improving the boiler system. The energy saving effect of each component increases with the decrease of load and has a greater influence under a lower load rate. The heat and mass transfer process takes priority in energy saving diagnosis of related components and processes. This makes great reference for the design and operation optimization of coal-fired power units.展开更多
基金supported by the National Basic Research Program of China("973"Project)(Grant No.2015CB251505)the National Natural Science Foundation of China(Grant No.51206049)+2 种基金the National Hi-Tech Research and Development Program of China("863"Project)(2012AA050604)the 111 Project(Grant No.B12034)the Fundamental Research Funds for the Central Universities(Grant No.2014XS29)
文摘In contrast to a traditional coal-fired power generation plant where steam extracted from a turbine is used to preheat the feedwater in all preheating stages, a solar-aided power generation(SAPG) plant uses solar heat to replace a part or all of the extracted steam in one or more preheating stages. The performance of an SAPG plant with different replacements is investigated in this study by using specific consumption theory(SCT). Fuel-specific and cost-specific consumption models for SAPG plants are built based on the SCT. A typical 330 MW coal-fired power plant is used as the study case. The performance of the SAPG plant in terms of specific consumption, with steam obtained from the first through the eighth(except for the fourth) stages of extraction replaced by solar heat, is compared with that of the reference coal-fired power plant. The fuel-specific consumption of the SAPG plant is determined to be lower than that of the reference coal-fired power plant. The fuel-specific consumption accrual distribution in SAPG plants is used to assess the effect of each individual replacement. Effective strategies to reduce the specific costs of the SAPG and coal-fired power plants are proposed based on the results of this study.
基金supported by the financial support of research projects from the National Key R&D Program of China(No.2021YFC2101000)Shanghai Scientific and Technological Innovation Action Plans-Scientific Instrument Development,China(grant No.21142201300,22142201000)+1 种基金National Natural Science Foundation of China(No.32071471 and No.22078295)Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX21_2866).
文摘Coenzyme Q10(CoQ10)is the most consumed dietary supplement and mainly biosynthesized by aerobic fermentation of Rhodobacter sphaeroides(R.sphaeroides).Oxygen supply was identified as a bottleneck for improving CoQ10 yield in R.sphaeroides.In this study,a precise regulation strategy based on dielectric spectroscopy(DS)was applied to further improve CoQ10 biosynthesis by R.sphaeroide.First,a quantitative response model among viable cells,cell morphology,and oxygen uptake rate(OUR)was established.DS could be used to detect viable R.sphaeroides cells,and the relationship among cell morphology,CoQ10 biosynthesis,and OUR was found to be significant.Based on this model,the online specific oxygen consumption rate(QO2)control strategy was successfully applied to the CoQ10 fermentation process.QO2 controlled at 0.07±0.01×10−7mmol/cell/h was most favorable for CoQ10 biosynthesis,resulting in a 28.3%increase in CoQ10 production.Based on the multi-parameters analysis and online QO2 control,a precise online nutrient feeding strategy was established using conductivity detected by DS.CoQ10 production was improved by 35%,reaching 3384 mg/L in 50 L bioreactors.This online control strategy would be effectively applied for improving industrial CoQ10 production,and the precise fermentation control strategy could also be applied to other fermentation process.
基金Item Sponsored by Fundamental Research Funds for the Central Universities of China(N090602007)National Key Technology Research and Development Program in 11th Five-Year Plan Project of China(2006BAE03A09)
文摘Theoretical minimum and actual specific energy consumptions （SEC） of typical manufacturing process （SMP） were studied. Firstly, a process division of a typical SMP in question was conducted with the theory of SEC analysis. Secondly, an exergy analysis model of a subsystem consisting of several parallel processes and a SEC analysis model of SMP were developed. And finally, based on the analysis models, the SEC of SMP was analyzed by means of the statistical significance. The results show that the SEC of typical SMP comprises the theoretical minimum SEC and the additional SEC derived from the irreversibility~ and the SMP has a theoretical minimum SEC of 6.74 GJ/t and an additional SEC of 19.32 GJ/t, which account for 25.88% and 74.12% of the actual SEC, respectively.
基金supported by the 2024 Tertiary Education Scientific Research Project of the Guangzhou Municipal Education Bureau(Grant No.2024312026),a grant from the Sugar Creek Packing Company,and the Dale A.Seiberling Endowment to the Food Engineering Research Laboratory at The Ohio State University。
文摘This study investigates the application of an enhanced Back-Propagation(BP)neural network model for analyzing and predicting beef microwave drying processes.Based on Fick’s second law of diffusion,effective moisture diffusivity was determined under varying microwave power levels(70-420 W)and relative humidity conditions(0%,30%,50%).Experimental results revealed moisture diffusivity values ranging from 2.23×10^(–9) to 2.87×10^(–8 )m^(2)/s.A significant inverse relationship was observed between microwave power and specific energy consumption,with optimal energy efficiency(8.39 MJ/kg water)achieved at 420 W.A multi-layer BP neural network architecture was developed to model drying kinetics and energy consumption patterns,with subsequent optimization using Sparrow Search Algorithm(SSA)for weight and threshold parameter calibration.Comparative analysis demonstrated that the SSA-optimized BP neural network significantly outperformed both conventional BP models and genetic algorithm-optimized variants in predictive accuracy.The enhanced model exhibited robust performance in predicting moisture content evolution and energy consumption dynamics throughout the drying process.These findings provide valuable insights for developing energy-efficient industrial-scale beef drying systems while maintaining product quality.The proposed intelligent computing framework represents a promising approach for precise modeling,prediction,and optimization of microwave drying processes in food processing applications.
文摘In some industrial plants, wastewater was intermittently or seasonally generated. There may be periods during which wastewater treatment facilities have to be set into an idle phase over several weeks. When wastewater was generated again, the activated sludge flocs may have disintegrated. In this experiment, re-activation characteristics of aerobic granular sludge starved for 2 months were investigated. Specific oxygen utilization rate(SOUR) was used as an indicator to evaluate the metabolic activity of the sludge. The results revealed that aerobic granular sludge could be stored up to two months without running the risk of losing the integrity of the granules and metabolic potentials. The apparent color of aerobic granules stored at room temperature gradually turned from brownish-yellowish to gray brown. They appeared brownish-yellowish again 2 weeks after re-activation. The velocity and strength of granules after 2-month idle period could be fully restored about 3 weeks after re-activation. Metabolic activity, however, dropped to 15 8 mg O_2/(g MLVSS·h), i.e. 74 % reduction after 2 months of storage. After restarting the reactor, it took 2 weeks that SOUR of up to 48 5 mg O_2 /(g MLVSS·h) was achieved. A stable effluent COD concentration of less than 150 mg/L was achieved during the re-activation process.
基金financially supported by the National Natural Science Foundation of China (Nos. 52175245 and 52274093)the Natural Science Foundation of Hubei Province (No. 2021CFB462)。
文摘To improve the rock breaking ability, cavitating waterjet and abrasive waterjet are combined by using a coaxial low-speed waterjet generated around the periphery of a high-speed abrasive waterjet, and a new type of waterjet called unsubmerged cavitating abrasive waterjet(UCAWJ) is thus produced. The rock breaking performance of UCAWJ was compared with submerged cavitating abrasive waterjet(SCAWJ)and unsubmerged abrasive waterjet(UAWJ) by impinging sandstone specimens. Moreover, the effects of jet pressure, standoff distance, abrasive flow rate and concentration were studied by evaluating the specific energy consumption, and the area, depth, and mass loss of the eroded specimen. The results show that the artificially generated submerged environment in UCAWJ is able to enhance the rock breaking performance under the same operating parameters. Furthermore, the rock breaking performance of UCAWJ is much better at higher jet pressures and smaller standoff distances when compared with UAWJ. The greatest rock breaking ability of UCAWJ appears at jet pressure of 50 MPa and standoff distance of 32 mm, with the mass loss of sandstone increased by 370.6% and the energy dissipation decreased by 75.8%. In addition, under the experimental conditions the optimal abrasive flow rate and concentration are 76.5 m L/min and 3%, respectively.
基金This research was supported by the National Natural Science Foundation of China(Grant No.51779143)the Cultivation of Scientific Research Ability of Young Talents of Shanghai jiao Tong University(Grant No.19×100040072).
文摘Slurry pipeline transport is widely used in several industrial processes.Calculating the specific power consumption(SPC)and determining the best working conditions are important for the design and operation of transportation systems.Based on the Shanghai Jiao Tong University high-concentration multi-sized slurry pressure drop(SJTU-HMSPD)pipeline-resistance-calculation model,the SJTU-SPC model for calculating the power required to transport a unit volume of solid materials over a unit pipeline length is established for a slurry transport system.The said system demonstrates a uniformity coefficient in the 1.26–7.98 range,median particle size of 0.075–4 mm,particle volume concentration of 10–60%,and pipeline diameter of 0.203–0.8 m.The results obtained were successfully verified against existing experimental data.The influence of parameters,such as particle-gradation uniformity coefficient,median particle size,pipe diameter,and particle volume concentration,on the SPC were analysed.The results revealed that the greater is the uniformity coefficient,the smaller is the minimum specific energy consumption and the larger the optimal transport concentration for a constant,median particle size slurry.As observed,the optimal transport concentration for broad-graded sand equalled approximately 48%.These results supplement the conclusions of existing research,indicating that the optimal transport concentration is approximately 30%and provides theoretical support for high concentration transportation of broad graded slurry.
基金Project(50875265) supported by the National Natural Science Foundation of ChinaProject(20080440992) supported by the Postdoctoral Science Foundation of ChinaProject(2009SK3159) supported by the Technology Support Plan of Hunan Province,China
文摘Under the condition of the designated collection ratio and the interfused ratio of mullock, to ensure the least energy consumption, the parameters of collecting head （the feed speed, the axes height of collecting head, and the rotate speed） are chosen as the optimized parameters. According to the force on the cutting pick, the collecting size of the cobalt crust and bedrock and the optimized energy consumption of the collecting head, the optimized design model of collecting head is built. Taking two hundred groups seabed microtopography for grand in the range of depth displacement from 4.5 to 5.5 era, then making use of the improved simulated annealing genetic algorithm （SAGA）, the corresponding optimized result can be obtained. At the same time, in order to speed up the controlling of collecting head, the optimization results are analyzed using the regression analysis method, and the conclusion of the second parameter of the seabed microtopography is drawn.
基金sponsored by New Energy and Industrial Development Organization(NEDO)supported by Japanese national government METI and relevant organizations
文摘Many industrial products made from fossil fuels cause the problems of global warming,depletion of fossil fuel resources and decrease of the land by landfill.In this report,the amounts of CO2 emissions as the environmental load and the specific energy consumptions as the depletion of fossil fuel resources of biodegradable plastics and conventional plastic as food trays are compared using life cycle assessment methodology.The amount of CO2 emission of PHB(poly(3-hydroxybutyrate-co-4-hydroxybutyrate)) tray was the smallest among those of trays of other plastics.The specific energy consumption of SPCL(starch/polycaprolactone) was the smallest among those of trays of other plastics.It clearly reveals that the utilization of the biodegradable plastics is an effective way of alternatives of the conventional plastics.
文摘This study presents hybrid clones of Corymbia spp.developed by Aperam BioEnergia as potential substitutes for Eucalyptus wood in the pulp industry.The biomass of Eucalyptus spp.was compared with that of Corymbia spp.by performing modified kraft pulping and basic density analyses.Comparisons were made by analyzing their respective mean annual increments of cellulose(MAI_(cel))and specific wood consumption(SWC),estimated using a kappa number of(19±1).The results showed that one of the hybrid clones(Corymbia citriodora×Corymbia torelliana,ID 4)had higher basic wood density,higher screened yield,better MAI_(cel#k19),and lower SWC than the other samples,reaching values of 0.608 t/m^(3),54.1%,24.6 ADt/ha/year(i.e.,air dry ton/hectare/year),and 2.74 m^(3)/ADt,respectively.Consequently,clone ID 4 had the highest MAI_(cel)/SWC ratio score(8.98).Given its high forest productivity and low industrial cost compared with other samples,as well as its advantages over Eucalyptus spp.wood,we concluded that clone ID 4 has great potential as an alternative biomass for pulp production.
文摘The authors studied diesel combustion improvement with a reformed fuel that mixed nano air-bubbles by using an EMNB （ejector-type micro-nano bubbler）. The EMNB performs adequately and is smaller （20 mm diameter, 34 mm length） than other micro-nano bubblers. It is quite possible to install it in an actual engine. An experiment was performed using a single cylinder engine with a dish or square shaped combustion chamber cavity, and in order to compare the engine speed change, we also used a four cylinder engine with a turbo-charger. The results showed that an improvement in specific fuel consumption, a decrease in the density of the exhaust smoke and an improvement in charging efficiency etc. were achieved by mixing nano bubbles into gas oil under most conditions. It is confirmed that combustion was promoted and improved by a physical and chemical action through mixing the nano bubbles into gas oil.
文摘The price of fuel oil continues to rise, decreased supplies oil at the other side, both factors increase the interest of researchers to conduct research related to fuel efficiency. Therefore the aim of this study is to improve the efficiency fuel of diesel engine using fuel filter. The method used for the research is testing the most efficient fuel filters made of coil wire coil winding 5,000, the three distinguished from the coil core diameter of 44.5, 28.5 and 17.5 mm in diesel engine. The performance test was conducted from 1,100 rpm to 1,700 rpm, the throttle opening of 30%-60%. The first testing was done by creating a constant speed 1,500 rpm and throttle opening varies from 30% to 60%, further testing is done by varying the rpm start from 1,100 rpm to 1,700 rpm to make constant valve 40% and 60%.
文摘The research presents an improved method of rational design of energy-efficient low-rise residential buildings according to their life cycle. The mathematical model for finding the optimal version of draft power-efficient residential building has been developed. For conditions of Ukraine the optimization problem has been set and solved （finding the optimal version of the draft energy-efficient buildings）. The calculations prove the fact that the construction of passive houses in Ukraine today is economically feasible. Scientific and practical regulations, outlined in the research, can be used by all participants of the investment programs, and energy-efficiency projects, renovation projects and developing normative-technical documents.
文摘The water quality and energy consumption of wastewater treatment plants(WWTPs)in Taihu Basin were evaluated on the basis of the operation data from 204 municipal WWTPs in the basin by using various statistical methods.The influent ammonia nitrogen(NH3-N)and total nitrogen(TN)of WWTPs in Taihu Basin showed normal distribution,whereas chemical oxygen demand(COD),biochemical oxygen demand(BOD5),suspended solid(SS),and total phosphorus(TP)showed positively skewed distribution.The influent BOD5/COD was 0.4%-0.6%,only 39.2%SS/BOD5 exceeded the standard by 36.3%,the average BOD5/TN was 3.82,and the probability of influent BOD5/TP>20 was 82.8%.The average energy consumption of WWTPs in Taihu Basin in 2017 was 0.458 kWh/m^3.The specific energy consumption of WWTPs with a daily treatment capacity of more than 5×10^4 m^3 in Taihu Basin was stable at 0.33 kWh/m^3.A power function relationship was observed between the reduction in COD and NH3-N and the specific energy consumption of pollutant reduction,and the higher the pollutant reduction is,the lower the specific energy consumption of pollutant reduction presents.In addition,a linear relationship existed between the energy consumption of WWTPs and the specific energy consumption of influent volume and pollutant reduction.Therefore,upgrading and operation with less energy consumption of WWTPs is imperative and the suggestions for Taihu WWTPs based on stringent discharge standard are proposed in detail.
基金supported by the National Key Research and Development Program of China(No.2018YFC040800202)the National Natural Science Foundation of China(Grant No.21878177)+1 种基金the Natural Science Foundation of Shandong Province(No.ZR2019LFG003)the grants from the Tai Shan Scholar Foundation(No.ts201511003)。
文摘Agriculture is the largest consumer of freshwater.Desalinated seawater is an important alternative water source for sustainable irrigation.However,some issues of the current desalination technology hinder its use for agriculture irrigation,including low boron removal and high energy consumption.This study systematically explored the feasibility of employing fertilizer drawn forward osmosis(FDFO)as an alternative to 2nd pass reverse osmosis(RO)by considering the boron removal performance and specific energy consumption(SEC).Different operating conditions were investigated,such as the boron and NaCl concentrations in feed solution(FS),draw solution(DS)concentration,pH,the volume ratio of FS to DS,membrane orientation,flow rate,and operating temperature.The results indicated that a low boron concentration in FS and high DS pH(pH=11.0)decreased the boron solute flux,and led to low final boron concentration in the DS.The other operating conditions had negligible influence on the final DS boron concentration.Also,a lower flow rate and higher specific water flux with certain permeate water volumes were conducive to reducing the SEC of the FDFO process.Overall,our study paves a new way of using FDFO in irrigation,which avoids the phytotoxicity and human health risk of boron.The results show the potential of FDFO as an alternative to 2nd pass RO for irrigation water production.
文摘To investigate the influence of ultrasound pretreatment on sludge anaerobic digestion,the ultrasound disintegration of residual sludge in water treatment of petrochemical plant was studied,and the mechanisms of ultrasound and medium were introduced.Experimental results indicate that ultrasound cavitation induces the rise of sludge temperature,which improves ultrasound disintegra-tion on sludge.U1trasound pretreatment can advance observ-ably the quantity of chemical oxygen demand in sludge supernatant fluid(SCOD),which increases with ultrasound intensity and sonication time.The degree of ultrasound disintegration increases with the specific energy input.When the specific energy input is l0000 kJ/kg of total dry solids,the degree of ultrasonic sludge disintegration reaches 40%.
基金supported by the National Key Technology R&D Program(Grant No.2014BAA06B01)the National Natural Science Foundation of China(Grant Nos.U1261210 and 51306050)
文摘Energy conservation in heating systems has great influence on overall sustainable development strategy. Heating technology, especially combined heat and power(CHP, cogeneration), has been attracting increased interest and rapidly developing in recent years. However, the theoretical potential of heating from the perspective of thermodynamics has not been clearly illustrated. This paper presents a theoretical analysis of heating systems based on the 1st and 2nd laws of thermodynamics using the specific fuel consumption(SFC) analysis method, clarifies the theoretical potential limitation of heating systems and illustrates the process of reversible heating on the basis of the total energy system. A novel concept(green heating, GH) and a new indicator(green-heating index, GH Index) are scientifically defined to characterise different options for heating and to quantitatively evaluate their fuel consumption levels. Thereafter, the fuel consumptions of four typical space heating modes are compared and discussed to present the application of GH theory and validate the power of the proposed concept and index. Furthermore, two different CHP technologies are analyzed with an instantiation case, and a novel CHP system is recommended, which may scientifically support the development of heating technology and further improve the processes of energy-saving and CO2 reduction.
文摘The energy-saving analytics of coal-fired power units in China is confronting new challenges especially with even more complicated system structure, higher working medium parameters, time-dependent varying operation conditions and boundaries such as load rate, coal quality, ambient temperature and humidity. Compared with the traditional optimization of specific operating parameters, the idea of the energy-consumption benchmark state was proposed. The equivalent specific fuel consumption(ESFC) analytics was introduced to determine the energy-consumption benchmark state, with the minimum ESFC under varying operation boundaries. Models for the energy-consumption benchmark state were established, and the endogenous additional specific consumption(ASFC) and exogenous ASFC were calculated. By comparing the benchmark state with the actual state, the energy-saving tempospacial effect can be quantified. As a case study, the energy consumption model of a 1000 MW ultra supercritical power unit was built. The results show that system energy consumption can be mainly reduced by improving the performance of turbine subsystem. This nearly doubles the resultant by improving the boiler system. The energy saving effect of each component increases with the decrease of load and has a greater influence under a lower load rate. The heat and mass transfer process takes priority in energy saving diagnosis of related components and processes. This makes great reference for the design and operation optimization of coal-fired power units.
