Two novel thermal cycles based on Brayton cycle and Rankine cycle are proposed, respectively, which integrate the recovery of low-level waste heat and Liquefied Nature Gas （LNG） cold energy utilization for power gen...Two novel thermal cycles based on Brayton cycle and Rankine cycle are proposed, respectively, which integrate the recovery of low-level waste heat and Liquefied Nature Gas （LNG） cold energy utilization for power generation. Cascade utilization of energy is realized in the two thermal cycles, where low-level waste heat,low-temperature exergy and pressure exergy of LNG are utilized efficiently through the system synthesis. The simulations are carried out using the commercial Aspen Plus 10.2, and the results are analyzed. Compared with the conventional Brayton cycle and Rankine cycle, the two novel cycles bring 60.94% and 60% in exergy efficiency, respectively and 53.08% and 52.31% in thermal efficiency, respectively.展开更多
In this study,a model of combined cooling,heating and power system with municipal solid waste(MSW)and liquefied natural gas(LNG)as energy sources was proposed and developed based on the energy demand of a large commun...In this study,a model of combined cooling,heating and power system with municipal solid waste(MSW)and liquefied natural gas(LNG)as energy sources was proposed and developed based on the energy demand of a large community,andMSW was classified and utilized.The systemoperated by determining power by heating load,and measures were taken to reduce operating costs by purchasing and selling LNG,natural gas(NG),cooling,heating,and power.Based on this system model,three operation strategies were proposed based on whether MSW was classified and the length of kitchen waste fermentation time,and each strategy was simulated hourly throughout the year.The results showed that the strategy of MSW classified and centralized fermentation of kitchen waste in summer(i.e.,strategy 3)required the least total amount of LNG for the whole year,which was 47701.77 t.In terms of total annual cost expenditure,strategy 3 had the best overall economy,with the lowest total annual expenditure of 2.7730×108 RMB at LNG and NG unit prices of 4 and 4.2 RMB/kg,respectively.The lower heating value of biogas produced by fermentation of kitchen waste from MSW being classified was higher than that of MSW before being classified,so the average annual thermal economy of the operating strategy of MSW being classified was better than that of MSW not being classified.Among the strategies in which MSW was classified and utilized,strategy 3 could better meet the load demand of users in the corresponding season,and thus this strategy had better thermal economy than the strategy of year-round fermentation of kitchen waste(i.e.,strategy 2).The hourly analysis data showed that the net electrical efficiency of the system varies in the same trend as the cooling,heating and power loads in all seasons,while the relationship between the energy utilization efficiency and load varied from season to season.This study can provide guidance for the practical application of MSW being classified in the system.展开更多
To use the potential heat of molten blast furnace slag completely, a CaO-Al2O3-SiO2 system glass （MSG） was prepared from the molten industrial slag. The corresponding method proposed in this study utilized both slag...To use the potential heat of molten blast furnace slag completely, a CaO-Al2O3-SiO2 system glass （MSG） was prepared from the molten industrial slag. The corresponding method proposed in this study utilized both slag and its potential heat, improving the production rate and avoiding the environmental pollution. Using appropriate techniques, an MSG with uniform color and superior performances was produced. Based on the experimental results and phase diagram, the chemical composition of MSG by mass is obtained as follows：CaO 27%-33%, SiO2 42%-51%, Al2O3 11%-14%, MgO 6%-8%, and Na2O＋K2O 1%-4%. Thermodynamic processes of MSG preparation were analyzed, and the phases and microstructures of MSG were investigated by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The results show that alkali metal oxides serve as the fluxes, calcium oxide serves as the stabilizer, and alumina reinforces the Si-O network. XRD and SEM analyses show that, the prepared MSG displays the glass-feature patterns, the melting process is more complete, and the melt viscosity is lowered with an increase in calcium oxide content;however, a continuous increase in slag content induces the crystalli-zation of glass, leading to the formation of glass subphase. The optimum content of molten slag in MSG is 67.37wt%. With respect to bend-ing strength and acid/alkali resistance, the performance of MSG is better than that of ordinary marble.展开更多
The large amount of heat produced from solid waste composting has stimulated great interest in heat recovery and utilization.This paper reviews the advances in composting heat recovery researches in the last decade.So...The large amount of heat produced from solid waste composting has stimulated great interest in heat recovery and utilization.This paper reviews the advances in composting heat recovery researches in the last decade.Some experimental results and theoretical studies on composting heat utilization are summarized.The results indicate a great potential for utilization of heat produced by the composting process.Common problems experienced by current methods are how to realize the maximum heat recovery without negatively impacting compost quality and the economics of heat recovery methods.Further advancement of these methods is currently receiving comprehensive interests,both academically and commercially.展开更多
The typical features for an integrated iron & steelmaking industry are high energy consumption and CO2 emission.The traditional BF-BOF process in an integrated Iron and steelmaking enterprise produces a large amou...The typical features for an integrated iron & steelmaking industry are high energy consumption and CO2 emission.The traditional BF-BOF process in an integrated Iron and steelmaking enterprise produces a large amount of residual heat and energy,which has great potential for recovery and abatement potential of CO2 emissions.In this paper,for an integrated Iron & steelmaking enterprise of 10 million tons per year in capacity,the residual heat and energy recovery analysis was conducted.It is indicateded that the residual heat and energy can be recovered as electric power by using present advanced process technology.By means of the distributed power generation,the residual heat and energy can be recovered,with a power generation capacity of 419.5 kWh per ton steel product.Accordingly,the abatement potential of CO2 emissions for an integrated iron & steel making enterprise was also evaluated,which indicated that about 398.5 kg CO2 could be reduced per ton steel product.展开更多
基金the Science and Technology Foundation of Shaanxi Province (No.2002K08-G9).
文摘Two novel thermal cycles based on Brayton cycle and Rankine cycle are proposed, respectively, which integrate the recovery of low-level waste heat and Liquefied Nature Gas （LNG） cold energy utilization for power generation. Cascade utilization of energy is realized in the two thermal cycles, where low-level waste heat,low-temperature exergy and pressure exergy of LNG are utilized efficiently through the system synthesis. The simulations are carried out using the commercial Aspen Plus 10.2, and the results are analyzed. Compared with the conventional Brayton cycle and Rankine cycle, the two novel cycles bring 60.94% and 60% in exergy efficiency, respectively and 53.08% and 52.31% in thermal efficiency, respectively.
基金support provided by the Nature Science Foundation of Shandong Province(ZR201709180049)the Shandong Key Research and Development Program(2019GSF109023).
文摘In this study,a model of combined cooling,heating and power system with municipal solid waste(MSW)and liquefied natural gas(LNG)as energy sources was proposed and developed based on the energy demand of a large community,andMSW was classified and utilized.The systemoperated by determining power by heating load,and measures were taken to reduce operating costs by purchasing and selling LNG,natural gas(NG),cooling,heating,and power.Based on this system model,three operation strategies were proposed based on whether MSW was classified and the length of kitchen waste fermentation time,and each strategy was simulated hourly throughout the year.The results showed that the strategy of MSW classified and centralized fermentation of kitchen waste in summer(i.e.,strategy 3)required the least total amount of LNG for the whole year,which was 47701.77 t.In terms of total annual cost expenditure,strategy 3 had the best overall economy,with the lowest total annual expenditure of 2.7730×108 RMB at LNG and NG unit prices of 4 and 4.2 RMB/kg,respectively.The lower heating value of biogas produced by fermentation of kitchen waste from MSW being classified was higher than that of MSW before being classified,so the average annual thermal economy of the operating strategy of MSW being classified was better than that of MSW not being classified.Among the strategies in which MSW was classified and utilized,strategy 3 could better meet the load demand of users in the corresponding season,and thus this strategy had better thermal economy than the strategy of year-round fermentation of kitchen waste(i.e.,strategy 2).The hourly analysis data showed that the net electrical efficiency of the system varies in the same trend as the cooling,heating and power loads in all seasons,while the relationship between the energy utilization efficiency and load varied from season to season.This study can provide guidance for the practical application of MSW being classified in the system.
基金financially supported by the Natural Science Foundation of Hebei Province of China(No.E2010000963)
文摘To use the potential heat of molten blast furnace slag completely, a CaO-Al2O3-SiO2 system glass （MSG） was prepared from the molten industrial slag. The corresponding method proposed in this study utilized both slag and its potential heat, improving the production rate and avoiding the environmental pollution. Using appropriate techniques, an MSG with uniform color and superior performances was produced. Based on the experimental results and phase diagram, the chemical composition of MSG by mass is obtained as follows：CaO 27%-33%, SiO2 42%-51%, Al2O3 11%-14%, MgO 6%-8%, and Na2O＋K2O 1%-4%. Thermodynamic processes of MSG preparation were analyzed, and the phases and microstructures of MSG were investigated by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The results show that alkali metal oxides serve as the fluxes, calcium oxide serves as the stabilizer, and alumina reinforces the Si-O network. XRD and SEM analyses show that, the prepared MSG displays the glass-feature patterns, the melting process is more complete, and the melt viscosity is lowered with an increase in calcium oxide content;however, a continuous increase in slag content induces the crystalli-zation of glass, leading to the formation of glass subphase. The optimum content of molten slag in MSG is 67.37wt%. With respect to bend-ing strength and acid/alkali resistance, the performance of MSG is better than that of ordinary marble.
基金would like to express their gratitude towards the financial support received from the National Natural Science Foundation of China(Grant No:51508345)the National Sparking Plan Project(2015GA650012)the Cultivation Plan for Youth Agricultural Science and Technology Innovative Talents of Liaoning Province(2014053).
文摘The large amount of heat produced from solid waste composting has stimulated great interest in heat recovery and utilization.This paper reviews the advances in composting heat recovery researches in the last decade.Some experimental results and theoretical studies on composting heat utilization are summarized.The results indicate a great potential for utilization of heat produced by the composting process.Common problems experienced by current methods are how to realize the maximum heat recovery without negatively impacting compost quality and the economics of heat recovery methods.Further advancement of these methods is currently receiving comprehensive interests,both academically and commercially.
基金supported by the National Basic Research Program of China ("973" Project) (Grant No.2007613507)the Intellectual Innovative Program of The Chinese Academy of Sciences (Grant No.KGCX-YW-323-1)the National "Eleventh Five" important science and technology supporting program (Grant No.2006BA02A14)
文摘The typical features for an integrated iron & steelmaking industry are high energy consumption and CO2 emission.The traditional BF-BOF process in an integrated Iron and steelmaking enterprise produces a large amount of residual heat and energy,which has great potential for recovery and abatement potential of CO2 emissions.In this paper,for an integrated Iron & steelmaking enterprise of 10 million tons per year in capacity,the residual heat and energy recovery analysis was conducted.It is indicateded that the residual heat and energy can be recovered as electric power by using present advanced process technology.By means of the distributed power generation,the residual heat and energy can be recovered,with a power generation capacity of 419.5 kWh per ton steel product.Accordingly,the abatement potential of CO2 emissions for an integrated iron & steel making enterprise was also evaluated,which indicated that about 398.5 kg CO2 could be reduced per ton steel product.
