This paper deals with thermodynamic chemical equilibrium analysis using the method of direct minimization of Gibbs free energy for all possible CH4 and CO2 reactions. The effects of CO2/CH4 feed ratio, reaction temper...This paper deals with thermodynamic chemical equilibrium analysis using the method of direct minimization of Gibbs free energy for all possible CH4 and CO2 reactions. The effects of CO2/CH4 feed ratio, reaction temperature, and system pressure on equilibrium composition, conversion, selectivity and yield were studied. In addition, carbon and no carbon formation regions were also considered at various reaction temperatures and CO2/CH4 feed ratios in the reaction system at equilibrium. It was found that the reaction temperature above 1100 K and CO2/CH4 ratio=1 were favourable for synthesis gas production with H2/CO ratio unity, while carbon dioxide oxidative coupling of methane （CO2 OCM） reaction to produce ethane and ethylene is less favourable thermodynamically. Numerical results indicated that the no carbon formation region was at temperatures above 1000 K and CO2/CH4 ratio larger than 1.展开更多
The sugar cane containing minimum 30% fiber was referred as bagasse and used the generation of power required for the operation of sugar mill. The bagasse is fired in the boiler for producing steam at high pressure, w...The sugar cane containing minimum 30% fiber was referred as bagasse and used the generation of power required for the operation of sugar mill. The bagasse is fired in the boiler for producing steam at high pressure, which is extracted through various single high capacity turbines and used in the process. The installation of high pressure boilers and high pressure turbo-generators has provision for the operation of co-generation plant during the off-season also that enhances the power generation from 9MW to 23MW. The annual monetary benefits achieved are Rs. 204.13 million and this was based on cost of power sold to the grid @ Rs 2.548 per unit, sugar season of 219 days and off season of 52 days. This required an investment of Rs 820.6 million. The investment had an attractive simple payback period of 48 months.展开更多
The coordinated control of multiple-sources including wind,photovoltaic(PV)and storage brings new challenges to traditional dispatch and control technologies.This paper firstly introduces a framework of wind,PV and st...The coordinated control of multiple-sources including wind,photovoltaic(PV)and storage brings new challenges to traditional dispatch and control technologies.This paper firstly introduces a framework of wind,PV and storage co-generation monitoring system.Then,key technologies of co-generation monitoring system including day-ahead optimal dispatching,active power coordinated control and reactive power and voltage control are proposed.The framework and the techniques described in this paper have been applied in the National Wind,Photovoltaic,Storage and Transmission Demonstration Project of China,and their validity have been tested and verified.展开更多
This paper is focused on description of cool production in using WHR （Waste Heat Technology） Technology-a new method of centralized production of heat by using the waste heat from generated exhaust gas, which has be...This paper is focused on description of cool production in using WHR （Waste Heat Technology） Technology-a new method of centralized production of heat by using the waste heat from generated exhaust gas, which has been in 2009 developed and operated by companies HELORO s.r.o, and COMTHERM s.r.o.展开更多
Coal measure gas(CMG),referring to natural gas stored in coal measures,as well as its existence,exploration and production,has been highly concerned recently in natural gas sector in China,and pilot tests of which hav...Coal measure gas(CMG),referring to natural gas stored in coal measures,as well as its existence,exploration and production,has been highly concerned recently in natural gas sector in China,and pilot tests of which have been succeeded with some achievements.To provide new geological references,this paper discussed the research progress in CMG co-existence and pooling factors in the respects of the tightening mechanism of coal measure sandstone reservoirs,CMG co-existence and gas pooling assemblages,the superimposed CMG system,and so on.The following findings were obtained.(1)The particularities of CMG geological conditions are shown in three aspects:First,the occurrence and reservoir lithology of CMG are diverse,and the accumulation of sandstone gas in coal measures may be different from that of conventional sandstone gas.Second,the sedimentary environment of coal measures causes the frequent and thin interbedding with various lithologic reservoirs,strong cyclicity and complex gasewater relationship,and the Surat-type CMG is worthy of attention.And third,the sandstone reservoirs in coal measures are embedded in the wide overlying mudstones,the special sourceereservoir match and composite gas reservoirs need to develop adaptive co-exploration and co-production technology.(2)The coal measures are rich in organic matters,and a large number of the organic acids are formed during gas generation from the source rocks,which are important factors for the densification of the sandstone reservoirs in coal measures.And the sandstone reservoirs in coal measures may be characteristic of self-generating and self-storing gas and adsorption to a certain extent,and their physical properties can be improved by organic detritus in the reservoirs.(3)The sedimentology of coal measures defines four generalities for favorable CMG accumulation,but effect of the gas-generating intensity,gas migration system,formation fluid energy and effective regional caprock thickness to the accumulation are variable.The natural gas generated in source rocks is re-allocated with a special migration system in a complex sourceereservoir system,which is an important basis of CMG accumulation.(4)The superimposition of the gas-bearing system is one of the leading problems in CMG research.In recent years,the logging response identification technology of key strata and the superposition identification method of the gas-bearing system have been further developed.It is found that there are three typical types of fluid pressure curves in coal measures.At the same time,the CMG co-accumulation in the whole sense requires a certain threshold depth.Based on the progress above,the theory of CMG accumulation has been improved and deepened,which is helpful in providing more pertinent suggestions for the development of the joint CMG exploration and production technology.展开更多
A large magnitude-9.0 earthquake struck northeast Japan on March 11, 2011. Thirty minutes later, a tsunami reached Tokyo Electric Power Corporation （TEPCO）＇s Fukushima Daiichi nuclear power station, and the emergen...A large magnitude-9.0 earthquake struck northeast Japan on March 11, 2011. Thirty minutes later, a tsunami reached Tokyo Electric Power Corporation （TEPCO）＇s Fukushima Daiichi nuclear power station, and the emergency diesel generators submerged under water. Three units of the reactor experienced meltdown, and hydrogen explosions occurred at reactor houses. The RIKEN Nishina Center （RNC） contributed to the radiation screening effort by providing human resources, instruments, and transportation. The RNC also carried out extraction work and sample tests for soil contamination. Last summer, RIKEN was legally required to save 15% （equivalent to 3.3 MW） of its allocated electricity in its contract, making it extremely difficult to conduct experiments using accelerators. Accelerator operation was thus reduced to a minimum during the first half of the year. The RNC has a gas-turbine-based co-generation system （CGS） with an electrical capacity of 6.5 MW. The CGS was operated non-stop until the end of the year. RIKEN is constructing two sets of CGSs, each with a capacity of 1.5 MW to be commissioned this autumn.展开更多
Introduction:The current worldwide electric power&heat&cool production has a negative impact on the environment by emissions and enormous leaks of low-potential waste heat.Transformation of unused industrial l...Introduction:The current worldwide electric power&heat&cool production has a negative impact on the environment by emissions and enormous leaks of low-potential waste heat.Transformation of unused industrial low power heat into“renewable heat”useful to enhance the efficiency of the system is essential and actual innovation in the field of worldwide environmental protection.By introducing and defining the terminology of low-potential,“renewable”,“green heat”has created a new,parallel category of research in the energy sector.Traditional co-generation systems produce heat for space heating and hot water and generate electricity.Moving to tri-generation allows growing demand for air conditioning for homes,offices and commercial spaces such as server rooms and switchboards to be met simultaneously or on a seasonal basis.Tri-generation,or combined cooling,heat and power,is the process by which some of the heat produced by a co-generation plant is used to generate chilled water for air conditioning or refrigeration.Usually an absorption chiller is linked to the plant to provide this functionality.The technical solution is related to the new efficient manner and system of simultaneous generation of heat/cold from multiple heat sources,which has not yet been known,but in practice required.New system also enables advantageous utilization of solar power in supporting of the cooling output.The innovative system can be operated also within the existing central heating distribution systems.展开更多
The main objective of this study is estimating environmental pollution of hybrid biomass and co-generation power plants. Efficiency of direct tapping of biomass is about 15%-20%. Consequently, about 80% of energy woul...The main objective of this study is estimating environmental pollution of hybrid biomass and co-generation power plants. Efficiency of direct tapping of biomass is about 15%-20%. Consequently, about 80% of energy would be waste in this method. While in co-generation power plant, this number could improve to more than 50%. Therefore, to achieve higher efficiency in utilizing biomass energy, co-generation power plants is proposed by using biogas as fuel instead of natural gas. Proposed system would be supplied thermal and electrical energy for non-urban areas of Iran. In this regard, process of fermentation and gas production from biomass in a vertical digester is studied and simulated using analytic methods. Various factors affecting the fermentation, such as temperature, humidity, PH and optimal conditions for the extraction of gas from waste agriculture and animal are also determined. Comparing between the pollution emission from fossil fuel power plants and power plants fed by biomass shows about 88% reduction in greenhouse emission which significant number.展开更多
In Japan, residential FCs （fuel cells） are being introduced not only in detached houses but also in collective housing. In this context, the effects of FC introduction （e.g., primary energy savings） should be quan...In Japan, residential FCs （fuel cells） are being introduced not only in detached houses but also in collective housing. In this context, the effects of FC introduction （e.g., primary energy savings） should be quantitatively evaluated, but this has not been done sufficiently for collective housing, particularly with regard to demand variability. Here, the authors propose a method taking into account demand variability to evaluate the effects of FC introduction into collective housing, based on a finite set of observational demand data. The method provides a new viewpoint for evaluating the effects of FC introduction. Numerical simulation results based on real-world data indicate the validity of these effects in terms of primary energy savings and CO2 reduction considering demand variability.展开更多
Solid particles instead of molten salt as a heat storage medium for extracted steam energy storage are essential in thermal power flexibility retrofit. This study constructs a charge-discharge experimental device usin...Solid particles instead of molten salt as a heat storage medium for extracted steam energy storage are essential in thermal power flexibility retrofit. This study constructs a charge-discharge experimental device using by-products from the steel industry as heat storage materials, similar to a battery cell, which is easily scalable and accomplishes the steam-solid particle-steam energy conversion. Investigation parameters include temperature distribution, power variation, and cycle efficiency for different charging and discharging modes. Results indicate that the charging mode II outperforms mode I in temperature uniformity, charging flow rate, and pressure loss, yielding higher charging power and total convective heat transfer coefficients at 13 kW and 275 W/(m^(2) K), respectively. The pilot device demonstrates commendable insulating properties. Its heat dissipation rate is approximately 33.33%, which surpasses that of reported thermal storage devices. Moreover, the mode II exhibits superior temperature non-uniformity during heat release, ensuring that 40 kg/h of superheated steam at 220 ℃ can be produced continuously for 5 min. The cycling efficiency is noteworthy, reaching 65% in low flow rate discharge, accompanied by 79% charging efficiency and 82% discharging efficiency. A temperature difference cloud map elucidates the primary phase change region, emphasizing preheating, evaporation, and superheating segments. Experimental results provide new ideas for combining waste elimination in the steel industry and energy storage in thermal power plants.展开更多
Developing an efficient freshwater and electricity co-generation device(FECGD)can solve the shortage of freshwater and electricity.However,the poor salt resistance and refrigeration properties of the materials for FEC...Developing an efficient freshwater and electricity co-generation device(FECGD)can solve the shortage of freshwater and electricity.However,the poor salt resistance and refrigeration properties of the materials for FECGD put big challenges in the efficient and stable operation of these devices.To address these issues,we propose the covalent organic framework(COF)confined co-polymerization strategy to prepare COF-modified acrylamide cationic hydrogels(ACH-COF),where hydrogen bonding interlocking between negatively charged polymer chains and COF pores can form a salt resistant hydrogel for stabilizing tunable passive interfacial cooling(TPIC).The FECPDs based on the TPIC and salt resistance of ACH-COF display a maximum output power density of 2.28 W m-2,which is 4.3 times higher than that of a commercial thermoelec-tric generator under one solar radiation.The production rate of freshwater can reach 2.74 kg m-2 h-1.Our results suggest that the high efficiency and scala-bility of the FECGD can hold the promise of alleviating freshwater and power shortages.展开更多
文摘This paper deals with thermodynamic chemical equilibrium analysis using the method of direct minimization of Gibbs free energy for all possible CH4 and CO2 reactions. The effects of CO2/CH4 feed ratio, reaction temperature, and system pressure on equilibrium composition, conversion, selectivity and yield were studied. In addition, carbon and no carbon formation regions were also considered at various reaction temperatures and CO2/CH4 feed ratios in the reaction system at equilibrium. It was found that the reaction temperature above 1100 K and CO2/CH4 ratio=1 were favourable for synthesis gas production with H2/CO ratio unity, while carbon dioxide oxidative coupling of methane （CO2 OCM） reaction to produce ethane and ethylene is less favourable thermodynamically. Numerical results indicated that the no carbon formation region was at temperatures above 1000 K and CO2/CH4 ratio larger than 1.
文摘The sugar cane containing minimum 30% fiber was referred as bagasse and used the generation of power required for the operation of sugar mill. The bagasse is fired in the boiler for producing steam at high pressure, which is extracted through various single high capacity turbines and used in the process. The installation of high pressure boilers and high pressure turbo-generators has provision for the operation of co-generation plant during the off-season also that enhances the power generation from 9MW to 23MW. The annual monetary benefits achieved are Rs. 204.13 million and this was based on cost of power sold to the grid @ Rs 2.548 per unit, sugar season of 219 days and off season of 52 days. This required an investment of Rs 820.6 million. The investment had an attractive simple payback period of 48 months.
文摘The coordinated control of multiple-sources including wind,photovoltaic(PV)and storage brings new challenges to traditional dispatch and control technologies.This paper firstly introduces a framework of wind,PV and storage co-generation monitoring system.Then,key technologies of co-generation monitoring system including day-ahead optimal dispatching,active power coordinated control and reactive power and voltage control are proposed.The framework and the techniques described in this paper have been applied in the National Wind,Photovoltaic,Storage and Transmission Demonstration Project of China,and their validity have been tested and verified.
文摘This paper is focused on description of cool production in using WHR （Waste Heat Technology） Technology-a new method of centralized production of heat by using the waste heat from generated exhaust gas, which has been in 2009 developed and operated by companies HELORO s.r.o, and COMTHERM s.r.o.
基金supported by the Key Project of Natural Science Foundation of China"Study on Dynamic Balance Mechanism of Deep Coal Measure Gas System"(No.41530314)the Special and Significant Project of National Science and Technology(Nos.2016ZX05066-01,2016ZX05044-02).
文摘Coal measure gas(CMG),referring to natural gas stored in coal measures,as well as its existence,exploration and production,has been highly concerned recently in natural gas sector in China,and pilot tests of which have been succeeded with some achievements.To provide new geological references,this paper discussed the research progress in CMG co-existence and pooling factors in the respects of the tightening mechanism of coal measure sandstone reservoirs,CMG co-existence and gas pooling assemblages,the superimposed CMG system,and so on.The following findings were obtained.(1)The particularities of CMG geological conditions are shown in three aspects:First,the occurrence and reservoir lithology of CMG are diverse,and the accumulation of sandstone gas in coal measures may be different from that of conventional sandstone gas.Second,the sedimentary environment of coal measures causes the frequent and thin interbedding with various lithologic reservoirs,strong cyclicity and complex gasewater relationship,and the Surat-type CMG is worthy of attention.And third,the sandstone reservoirs in coal measures are embedded in the wide overlying mudstones,the special sourceereservoir match and composite gas reservoirs need to develop adaptive co-exploration and co-production technology.(2)The coal measures are rich in organic matters,and a large number of the organic acids are formed during gas generation from the source rocks,which are important factors for the densification of the sandstone reservoirs in coal measures.And the sandstone reservoirs in coal measures may be characteristic of self-generating and self-storing gas and adsorption to a certain extent,and their physical properties can be improved by organic detritus in the reservoirs.(3)The sedimentology of coal measures defines four generalities for favorable CMG accumulation,but effect of the gas-generating intensity,gas migration system,formation fluid energy and effective regional caprock thickness to the accumulation are variable.The natural gas generated in source rocks is re-allocated with a special migration system in a complex sourceereservoir system,which is an important basis of CMG accumulation.(4)The superimposition of the gas-bearing system is one of the leading problems in CMG research.In recent years,the logging response identification technology of key strata and the superposition identification method of the gas-bearing system have been further developed.It is found that there are three typical types of fluid pressure curves in coal measures.At the same time,the CMG co-accumulation in the whole sense requires a certain threshold depth.Based on the progress above,the theory of CMG accumulation has been improved and deepened,which is helpful in providing more pertinent suggestions for the development of the joint CMG exploration and production technology.
文摘A large magnitude-9.0 earthquake struck northeast Japan on March 11, 2011. Thirty minutes later, a tsunami reached Tokyo Electric Power Corporation （TEPCO）＇s Fukushima Daiichi nuclear power station, and the emergency diesel generators submerged under water. Three units of the reactor experienced meltdown, and hydrogen explosions occurred at reactor houses. The RIKEN Nishina Center （RNC） contributed to the radiation screening effort by providing human resources, instruments, and transportation. The RNC also carried out extraction work and sample tests for soil contamination. Last summer, RIKEN was legally required to save 15% （equivalent to 3.3 MW） of its allocated electricity in its contract, making it extremely difficult to conduct experiments using accelerators. Accelerator operation was thus reduced to a minimum during the first half of the year. The RNC has a gas-turbine-based co-generation system （CGS） with an electrical capacity of 6.5 MW. The CGS was operated non-stop until the end of the year. RIKEN is constructing two sets of CGSs, each with a capacity of 1.5 MW to be commissioned this autumn.
文摘Introduction:The current worldwide electric power&heat&cool production has a negative impact on the environment by emissions and enormous leaks of low-potential waste heat.Transformation of unused industrial low power heat into“renewable heat”useful to enhance the efficiency of the system is essential and actual innovation in the field of worldwide environmental protection.By introducing and defining the terminology of low-potential,“renewable”,“green heat”has created a new,parallel category of research in the energy sector.Traditional co-generation systems produce heat for space heating and hot water and generate electricity.Moving to tri-generation allows growing demand for air conditioning for homes,offices and commercial spaces such as server rooms and switchboards to be met simultaneously or on a seasonal basis.Tri-generation,or combined cooling,heat and power,is the process by which some of the heat produced by a co-generation plant is used to generate chilled water for air conditioning or refrigeration.Usually an absorption chiller is linked to the plant to provide this functionality.The technical solution is related to the new efficient manner and system of simultaneous generation of heat/cold from multiple heat sources,which has not yet been known,but in practice required.New system also enables advantageous utilization of solar power in supporting of the cooling output.The innovative system can be operated also within the existing central heating distribution systems.
文摘The main objective of this study is estimating environmental pollution of hybrid biomass and co-generation power plants. Efficiency of direct tapping of biomass is about 15%-20%. Consequently, about 80% of energy would be waste in this method. While in co-generation power plant, this number could improve to more than 50%. Therefore, to achieve higher efficiency in utilizing biomass energy, co-generation power plants is proposed by using biogas as fuel instead of natural gas. Proposed system would be supplied thermal and electrical energy for non-urban areas of Iran. In this regard, process of fermentation and gas production from biomass in a vertical digester is studied and simulated using analytic methods. Various factors affecting the fermentation, such as temperature, humidity, PH and optimal conditions for the extraction of gas from waste agriculture and animal are also determined. Comparing between the pollution emission from fossil fuel power plants and power plants fed by biomass shows about 88% reduction in greenhouse emission which significant number.
文摘In Japan, residential FCs （fuel cells） are being introduced not only in detached houses but also in collective housing. In this context, the effects of FC introduction （e.g., primary energy savings） should be quantitatively evaluated, but this has not been done sufficiently for collective housing, particularly with regard to demand variability. Here, the authors propose a method taking into account demand variability to evaluate the effects of FC introduction into collective housing, based on a finite set of observational demand data. The method provides a new viewpoint for evaluating the effects of FC introduction. Numerical simulation results based on real-world data indicate the validity of these effects in terms of primary energy savings and CO2 reduction considering demand variability.
基金This work was supported by the Fundamental Research Funds for the Central Universities(grant No.2022ZFJH04)。
文摘Solid particles instead of molten salt as a heat storage medium for extracted steam energy storage are essential in thermal power flexibility retrofit. This study constructs a charge-discharge experimental device using by-products from the steel industry as heat storage materials, similar to a battery cell, which is easily scalable and accomplishes the steam-solid particle-steam energy conversion. Investigation parameters include temperature distribution, power variation, and cycle efficiency for different charging and discharging modes. Results indicate that the charging mode II outperforms mode I in temperature uniformity, charging flow rate, and pressure loss, yielding higher charging power and total convective heat transfer coefficients at 13 kW and 275 W/(m^(2) K), respectively. The pilot device demonstrates commendable insulating properties. Its heat dissipation rate is approximately 33.33%, which surpasses that of reported thermal storage devices. Moreover, the mode II exhibits superior temperature non-uniformity during heat release, ensuring that 40 kg/h of superheated steam at 220 ℃ can be produced continuously for 5 min. The cycling efficiency is noteworthy, reaching 65% in low flow rate discharge, accompanied by 79% charging efficiency and 82% discharging efficiency. A temperature difference cloud map elucidates the primary phase change region, emphasizing preheating, evaporation, and superheating segments. Experimental results provide new ideas for combining waste elimination in the steel industry and energy storage in thermal power plants.
基金National Natural Science Foundation of China,Grant/Award Numbers:22108125,22175094Natural Science Foundation of Jiangsu Province,Grant/Award Number:BK20210627+1 种基金China Postdoctoral Science Foundation,Grant/Award Number:2023M730484Postgraduate Research&Practice Innovation Program of Jiangsu Province,Grant/Award Number:KYCX23_1173。
文摘Developing an efficient freshwater and electricity co-generation device(FECGD)can solve the shortage of freshwater and electricity.However,the poor salt resistance and refrigeration properties of the materials for FECGD put big challenges in the efficient and stable operation of these devices.To address these issues,we propose the covalent organic framework(COF)confined co-polymerization strategy to prepare COF-modified acrylamide cationic hydrogels(ACH-COF),where hydrogen bonding interlocking between negatively charged polymer chains and COF pores can form a salt resistant hydrogel for stabilizing tunable passive interfacial cooling(TPIC).The FECPDs based on the TPIC and salt resistance of ACH-COF display a maximum output power density of 2.28 W m-2,which is 4.3 times higher than that of a commercial thermoelec-tric generator under one solar radiation.The production rate of freshwater can reach 2.74 kg m-2 h-1.Our results suggest that the high efficiency and scala-bility of the FECGD can hold the promise of alleviating freshwater and power shortages.
