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Characteristics Analysis of Integrated CAES and CFPP Trigeneration System Considering Working Conditions

Jiajia Li,Peigang Yan,Guowen Zhou,Xingshuo Li,Qiang Li,Jinfu Liu,Daren Yu,

《工程（英文）》 doi: 10.1016/j.eng.2023.06.015

摘要： To meet the goal of worldwide decarbonization, the transformation process toward clean and green energy structures has accelerated. In this context, coal-fired power plant (CFPPs) and large-scale energy storage represented by compressed air energy storage (CAES) technology, are tasked with increasing renewable resource accommodation and maintaining the power system security. To achieve this, this paper proposes the concept of a CFPP–CAES combined cycle and a trigenerative system based on that. Considering the working conditions of the CFPP, thermal characteristics of three typical operation modes were studied and some general regularities were identified. The results of various potential integration schemes discussion indicated that extracting water from low-temperature points in the feedwater system to cool pressurized air and simultaneously increase the backwater temperature is beneficial for improving performance. In addition, preheating the pressurized air before the air expanders via low-grade water in the feedwater system as much as possible and reducing extracted steam contribute to increasing the efficiency. With the optimal integration scheme, 2.85 tonnes of coal can be saved per cycle and the round-trip efficiency can be increased by 2.24%. Through the cogeneration of heat and power, the system efficiency can reach 77.5%. In addition, the contribution degree of the three compression heat utilization methods to the performance improvement ranked from high to low, is preheating the feedwater before the boiler, supplying heat, and flowing into the CFPP feedwater system. In the cooling energy generation mode, the system efficiency can be increased to over 69%. Regardless of the operation mode, the benefit produced by integration is further enhanced when the CFPP operates at higher operating conditions because the coupling points parameters are changed. In addition, the dynamic payback period can be shortened by 11.33 years and the internal rate of return increases by 5.20% under a typical application scenario. Regarding the effect of different application scenarios in terms of economics, investing in the proposed system is more appropriate in regions with multiple energy demands, especially heating demand. These results demonstrate the technical advantages of the proposed system and provide guiding principles for its design, operation, and project investment.

关键词： Compressed air energy storage     CFPP–CAES combined cycle     Thermodynamic performance     Technical economics    

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Performance analysis of combined cycle power plant

Nikhil DEV,Rajesh ATTRI

《能源前沿（英文）》 2015年 第9卷 第4期   页码 371-386 doi: 10.1007/s11708-015-0371-9

摘要： Combined cycle power plants (CCPPs) are in operation with diverse thermodynamic cycle configurations. Assortment of thermodynamic cycle for scrupulous locality is dependent on the type of fuel available and different utilities obtained from the plant. In the present paper, seven of the practically applicable configurations of CCPP are taken into consideration. Exergetic and energetic analysis of each component of the seven configurations is conducted with the help of computer programming tool, i.e., engineering equation solver (EES) at different pressure ratios. For Case 7, the effects of pressure ratio, turbine inlet temperature and ambient relative humidity on the first and second law is studied. The thermodynamics analysis indicates that the exergy destruction in various components of the combined cycle is significantly affected by the overall pressure ratio, turbine inlet temperature and pressure loss in air filter and less affected by the ambient relative humidity.

关键词： first-law     second-law     exergy destruction     components    

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Life cycle assessment of low impact development technologies combined with conventional centralized water

Hyunju Jeong, Osvaldo A. Broesicke, Bob Drew, Duo Li, John C. Crittenden

《环境科学与工程前沿（英文）》 2016年 第10卷 第6期 doi: 10.1007/s11783-016-0851-0

摘要： Hybrid system of LID technologies and conventional system was examined. Bioretention areas, rainwater harvesting, and xeriscaping were considered. Technology feasibility was simulated for land use and population density. Synergistic effects of technologies were quantified in defined zones. Uncertainty test was conducted with pedigree matrix and Monte Carlo analysis. Low-impact development (LID) technologies, such as bioretention areas, rooftop rainwater harvesting, and xeriscaping can control stormwater runoff, supply non-potable water, and landscape open space. This study examines a hybrid system (HS) that combines LID technologies with a centralized water system to lessen the burden on a conventional system (CS). CS is defined as the stormwater collection and water supply infrastructure, and the conventional landscaping choices in the City of Atlanta. The study scope is limited to five single-family residential zones (SFZs), classified R-1 through R-5, and four multi-family residential zones (MFZs), classified RG-2 through RG-5. Population density increases from 0.4 (R-1) to 62.2 (RG-5) persons per 1,000 m . We performed a life cycle assessment (LCA) comparison of CS and HS using TRACI 2.1 to simulate impacts on the ecosystem, human health, and natural resources. We quantified the impact of freshwater consumption using the freshwater ecosystem impact (FEI) indicator. Test results indicate that HS has a higher LCA single score than CS in zones with a low population density; however, the difference becomes negligible as population density increases. Incorporating LID in SFZs and MFZs can reduce potable water use by an average of 50% and 25%, respectively; however, water savings are negligible in zones with high population density (i.e., RG-5) due to the diminished surface area per capita available for LID technologies. The results demonstrate that LID technologies effectively reduce outdoor water demand and therefore would be a good choice to decrease the water consumption impact in the City of Atlanta.

关键词： Life cycle assessment (LCA)     Low impact development (LID)     Bioretention area     Rainwater harvesting     Xeriscaping    

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A comparison of production system life cycle models

Rajesh ATTRI, Sandeep GROVER

《机械工程前沿（英文）》 2012年 第7卷 第3期   页码 305-311 doi: 10.1007/s11465-012-0332-5

摘要：

Companies today need to keep up with the rapidly changing market conditions to stay competitive. The main issues in this paper are related to a company’s market and its competitors. The prediction of market behavior is helpful for a manufacturing enterprise to build efficient production systems. However, these predictions are usually not reliable. A production system is required to adapt to changing markets, but such requirement entails higher cost. Hence, analyzing different life cycle models of the production system is necessary. In this paper, different life cycle models of the production system are compared to evaluate the distinctive features and the limitations of each model. Furthermore, the difference between product life cycle and production life cycle is summarized, and the effect of product life cycle on production life cycle is explained. Finally, a production system life cycle model, along with key activities to be performed in each stage, is proposed specifically for the manufacturing sector.

关键词： production system     life cycle     model     product    

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Development of combined transitional pavement structure for urban tram track-road grade crossings

《结构与土木工程前沿（英文）》   页码 1199-1210 doi: 10.1007/s11709-023-0949-y

摘要： The grade crossings and adjacent pavements of urban trams are generally subjected to complex load conditions and are susceptible to damage. Therefore, in this study, a novel pavement structure between tram tracks and roads constructed using polyurethane (PU) elastic concrete and ultra-high-performance concrete (UHPC), referred to as a track-road transitional pavement (TRTP), is proposed. Subsequently, its performance and feasibility are evaluated using experimental and numerical methods. First, the mechanical properties of the PU elastic concrete are evaluated. The performance of the proposed structure is investigated using a three-dimensional finite element model, where vehicle-induced dynamic and static loads are considered. The results show that PU elastic concrete and the proposed combined TRTP are applicable and functioned as intended. Additionally, the PU elastic concrete achieved sufficient performance. The recommended width of the TRTP is approximately 50 mm. Meanwhile, the application of UHPC under a PU elastic concrete layer significantly reduces vertical deformation. Results of numerical calculations confirmed the high structural performance and feasibility of the proposed TRTP. Finally, material performance standards are recommended to provide guidance for pavement design and the construction of tram-grade crossings in the future.

关键词： urban tram track     grade crossing     combined track-road transitional pavement     polyurethane elastic concrete     finite element method    

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Analysis on carbon emission reduction intensity of fuel cell vehicles from a life-cycle perspective

《能源前沿（英文）》 doi: 10.1007/s11708-023-0909-1

摘要： The hydrogen fuel cell vehicle is rapidly developing in China for carbon reduction and neutrality. This paper evaluated the life-cycle cost and carbon emission of hydrogen energy via lots of field surveys, including hydrogen production and packing in chlor-alkali plants, transport by tube trailers, storage and refueling in hydrogen refueling stations (HRSs), and application for use in two different cities. It also conducted a comparative study for battery electric vehicles (BEVs) and internal combustion engine vehicles (ICEVs). The result indicates that hydrogen fuel cell vehicle (FCV) has the best environmental performance but the highest energy cost. However, a sufficient hydrogen supply can significantly reduce the carbon intensity and FCV energy cost of the current system. The carbon emission for FCV application has the potential to decrease by 73.1% in City A and 43.8% in City B. It only takes 11.0%–20.1% of the BEV emission and 8.2%–9.8% of the ICEV emission. The cost of FCV driving can be reduced by 39.1% in City A. Further improvement can be obtained with an economical and “greener” hydrogen production pathway.

关键词： hydrogen energy     life-cycle assessment (LCA)     fuel cell vehicle     carbon emission     energy cost    

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emissions: a comparative study of the feasibility of the hybrid renewable energy systems incorporating combined

《能源前沿（英文）》 2022年 第16卷 第2期   页码 336-356 doi: 10.1007/s11708-021-0748-x

摘要： Fuel poverty is most prevalent in North East England with 14.4% of fuel poor households in Newcastle upon Tyne. The aim of this paper was to identify a grid connected renewable energy system coupled with natural gas reciprocating combined heat and power unit, that is cost-effective and technically feasible with a potential to generate a profit from selling energy excess to the grid to help alleviate fuel poverty. The system was also aimed at low carbon emissions. Fourteen models were designed and optimized with the aid of the HOMER Pro software. Models were compared with respect to their economic, technical, and environmental performance. A solution was proposed where restrictions were placed on the size of renewable energy components. This configuration consists of 150 kW CHP, 300 kW PV cells, and 30 kW wind turbines. The renewable fraction is 5.10% and the system yields a carbon saving of 7.9% in comparison with conventional systems. The initial capital investment is $1.24 million which enables the system to have grid sales of 582689 kWh/a. A conservative calculation determined that 40% of the sales can be used to reduce the energy cost of fuel poor households by $706 per annum. This solution has the potential to eliminate fuel poverty at the site analyzed.

关键词： greenhouse gas control     low carbon target     grid connected     renewable fraction     fuel poverty     combined heat and power     HOMER Pro    

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Interaction and combined toxicity of microplastics and per- and polyfluoroalkyl substances in aquatic

《环境科学与工程前沿（英文）》 2022年 第16卷 第10期 doi: 10.1007/s11783-022-1571-2

摘要：

● Adsorption of PFASs on MPs and its mechanisms are critically reviewed.

关键词： Microplastics     Per- and Polyfluoroalkyl substances     Adsorption     Transport     Transformation    

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Improvement of the cascading closed loop cycle system

ZHANG Guoqiang, CAI Ruixian

《能源前沿（英文）》 2007年 第1卷 第3期   页码 341-346 doi: 10.1007/s11708-007-0051-5

摘要： Aspen Plus was used to simulate and get more information about the cascading closed loop cycle (CCLC) system [1–3]. Following evaluation of the variable temperature heat source (e.g. gas turbine flue gas) utilized by the CCLC, both qualitative and quantitive comparisons between the system and simple steam Rankine cycle, were made. The results indicate that CCLC has the advantage in recuperating exergy from flue gas, but it cannot sufficiently convert the recuperated exergy to useful work. To improve the utilization of low temperature flue gas heat, the properties and parameters of the working substance must match conditions of the low temperature heat source. A better cycle scheme and pressure distribution was proposed to raise the efficiency of the CCLC. In addition, the multifunction system concept was introduced to improve the performance of CCLC with solar energy.
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Experimental study on combined buoyant-thermocapillary flow along with rising liquid film on the surface

Manuel J. GOMES, Ning MEI

《能源前沿（英文）》 2020年 第14卷 第1期   页码 114-126 doi: 10.1007/s11708-017-0483-5

摘要： Temperature distribution and variation with time has been considered in the analysis of the influences of the initial level of immersion of a horizontal metallic mesh tube in the liquid on combined buoyant and thermo-capillary flow. The combined flow occurs along with the rising liquid film flow on the surface of a horizontal metallic mesh tube. Three different levels of immersion of the metallic mesh tube in the liquid have been tested. Experiments of 60 min in duration have been performed using a heating metallic tube with a diameter of 25 mm and a length of 110 mm, sealed outside with a metallic mesh of 178 mm by 178 mm, and distilled water. These reveal two distinct flow patterns. Thermocouples and infrared thermal imager are utilized to measure the temperature. The level of the liquid free surface relative to the lower edge of the tube is measured as angle . The results show that for a smaller angle, or a low level of immersion, with a relatively low heating power, it is possible to near fully combine the upwards buoyant flow with the rising liquid film flow. In this case, the liquid is heated only in the vicinity of the tube, while the liquid away from the flow region experiences small changes in temperature and the system approaches steady conditions. For larger angles, or higher levels of immersion, a different flow pattern is noticed on the liquid free surface and identified as the thermo-capillary (Marangoni) flow. The rising liquid film is also present. The higher levels of immersion cause a high temperature gradient in the liquid free surface region and promote thermal stratification; therefore the system could not approach steady conditions.

关键词： rising liquid film     combined flow     thermo-capillary flow     buoyant flow     metallic mesh tube     horizontal tube    

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State-of-the-art applications of machine learning in the life cycle of solid waste management

《环境科学与工程前沿（英文）》 2023年 第17卷 第4期 doi: 10.1007/s11783-023-1644-x

摘要：

● State-of-the-art applications of machine learning (ML) in solid waste (SW) is presented.

关键词： Machine learning (ML)     Solid waste (SW)     Bibliometrics     SW management     Energy utilization     Life cycle    

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Simulation and experiments on a solid sorption combined cooling and power system driven by the exhaust

Peng GAO, Liwei WANG, Ruzhu WANG, Yang YU

《能源前沿（英文）》 2017年 第11卷 第4期   页码 516-526 doi: 10.1007/s11708-017-0511-5

摘要： A solid sorption combined cooling and power system driven by exhaust waste heat is proposed, which consists of a MnCl sorption bed, a CaCl sorption bed, an evaporator, a condenser, an expansion valve, and a scroll expander, and ammonia is chosen as the working fluid. First, the theoretical model of the system is established, and the partitioning calculation method is proposed for sorption beds. Next, the experimental system is established, and experimental results show that the refrigerating capacity at the refrigerating temperature of –10°C and the resorption time of 30 min is 1.95 kW, and the shaft power is 109.2 W. The system can provide approximately 60% of the power for the evaporator fan and the condenser fan. Finally, the performance of the system is compared with that of the solid sorption refrigeration system. The refrigerating capacity of two systems is almost the same at the same operational condition. Therefore, the power generation process does not influence the refrigeration process. The exergy efficiency of the two systems is 0.076 and 0.047, respectively. The feasibility of the system is determined, which proves that this system is especially suitable for the exhaust waste heat recovery.

关键词： solid sorption     exhaust waste heat     combined cooling and power system     exergy efficiency    

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Sulfur cycle as an electron mediator between carbon and nitrate in a constructed wetland microcosm

Wenrui Guo, Yue Wen, Yi Chen, Qi Zhou

《环境科学与工程前沿（英文）》 2020年 第14卷 第4期 doi: 10.1007/s11783-020-1236-y

摘要： • Fe(III) accepted the most electrons from organics, followed by NO3‒, SO42‒, and O2. • The electrons accepted by SO42‒ could be stored in the solid AVS, FeS2-S, and S0. • The autotrophic denitrification driven by solid S had two-phase characteristics. • A conceptual model involving electron acceptance, storage, and donation was built. • S cycle transferred electrons between organics and NO3‒ with an efficiency of 15%. A constructed wetland microcosm was employed to investigate the sulfur cycle-mediated electron transfer between carbon and nitrate. Sulfate accepted electrons from organics at the average rate of 0.84 mol/(m3·d) through sulfate reduction, which accounted for 20.0% of the electron input rate. The remainder of the electrons derived from organics were accepted by dissolved oxygen (2.6%), nitrate (26.8%), and iron(III) (39.9%). The sulfide produced from sulfate reduction was transformed into acid-volatile sulfide, pyrite, and elemental sulfur, which were deposited in the substratum, storing electrons in the microcosm at the average rate of 0.52 mol/(m3·d). In the presence of nitrate, the acid-volatile and elemental sulfur were oxidized to sulfate, donating electrons at the average rate of 0.14 mol/(m3·d) and driving autotrophic denitrification at the average rate of 0.30 g N/(m3·d). The overall electron transfer efficiency of the sulfur cycle for autotrophic denitrification was 15.3%. A mass balance assessment indicated that approximately 50% of the input sulfur was discharged from the microcosm, and the remainder was removed through deposition (49%) and plant uptake (1%). Dominant sulfate-reducing (i.e., Desulfovirga, Desulforhopalus, Desulfatitalea, and Desulfatirhabdium) and sulfur-oxidizing bacteria (i.e., Thiohalobacter, Thiobacillus, Sulfuritalea, and Sulfurisoma), which jointly fulfilled a sustainable sulfur cycle, were identified. These results improved understanding of electron transfers among carbon, nitrogen, and sulfur cycles in constructed wetlands, and are of engineering significance.

关键词： Constructed wetland     Sulfur cycle     Electron transfer     Denitrification    

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Carbon emission impact on the operation of virtual power plant with combined heat and power system

Yu-hang XIA,Jun-yong LIU,Zheng-wen HUANG,Xu ZHANG

《信息与电子工程前沿（英文）》 2016年 第17卷 第5期   页码 479-488 doi: 10.1631/FITEE.1500467

摘要： A virtual power plant (VPP) can realize the aggregation of distributed generation in a certain region, and represent distributed generation to participate in the power market of the main grid. With the expansion of VPPs and ever-growing heat demand of consumers, managing the effect of fluctuations in the amount of available renewable resources on the operation of VPPs and maintaining an economical supply of electric power and heat energy to users have been important issues. This paper proposes the allocation of an electric boiler to realize wind power directly converted for supplying heat, which can not only overcome the limitation of heat output from a combined heat and power (CHP) unit, but also reduce carbon emissions from a VPP. After the electric boiler is considered in the VPP operation model of the combined heat and power system, a multi-objective model is built, which includes the costs of carbon emissions, total operation of the VPP and the electricity traded between the VPP and the main grid. The model is solved by the CPLEX package using the fuzzy membership function in Matlab, and a case study is presented. The power output of each unit in the case study is analyzed under four scenarios. The results show that after carbon emission is taken into account, the output of low carbon units is significantly increased, and the allocation of an electric boiler can facilitate the maximum absorption of renewable energy, which also reduces carbon emissions from the VPP.

关键词： Virtual power plant (VPP)     Carbon emissions     Electric boiler     Wind power     Combined heat and power (CHP)    

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Life-cycle cost analysis of optimal timing of pavement preservation

Zilong WANG,Hao WANG

《结构与土木工程前沿（英文）》 2017年 第11卷 第1期   页码 17-26 doi: 10.1007/s11709-016-0369-3

摘要： Optimal application of pavement preservation or preventive maintenance is critical for highway agencies to allocate the limited budget for different treatments. This study developed an integrated life-cycle cost analysis (LCCA) model to quantify the impact of pavement preservation on agency cost and vehicle operation cost (VOC) and analyzed the optimal timing of preservation treatments. The international roughness index (IRI) data were extracted from the long-term pavement performance (LTPP) program specific pavement studies 3 (SPS-3) to determine the long-term effectiveness of preservation treatments on IRI deterioration. The traffic loading and the initial IRI value significantly affects life extension and the benefit of agency cost caused by pavement preservation. The benefit in VOC is one to two orders greater in magnitude as compared to the benefit in agency cost. The optimal timing calculated based on VOC is always earlier than the optimal timing calculated based on agency cost. There are considerable differences among the optimal timing of three preservation treatments.

关键词： pavement preservation     life-cycle cost analysis     agency cost     vehicle operation cost    

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标题 作者 时间 类型 操作

Characteristics Analysis of Integrated CAES and CFPP Trigeneration System Considering Working Conditions

Jiajia Li,Peigang Yan,Guowen Zhou,Xingshuo Li,Qiang Li,Jinfu Liu,Daren Yu,

期刊论文

Performance analysis of combined cycle power plant

Nikhil DEV,Rajesh ATTRI

期刊论文

Life cycle assessment of low impact development technologies combined with conventional centralized water

Hyunju Jeong, Osvaldo A. Broesicke, Bob Drew, Duo Li, John C. Crittenden

期刊论文

A comparison of production system life cycle models

Rajesh ATTRI, Sandeep GROVER

期刊论文

Development of combined transitional pavement structure for urban tram track-road grade crossings

期刊论文

Analysis on carbon emission reduction intensity of fuel cell vehicles from a life-cycle perspective

期刊论文

emissions: a comparative study of the feasibility of the hybrid renewable energy systems incorporating combined

期刊论文

Interaction and combined toxicity of microplastics and per- and polyfluoroalkyl substances in aquatic

期刊论文

Improvement of the cascading closed loop cycle system

ZHANG Guoqiang, CAI Ruixian

期刊论文

Experimental study on combined buoyant-thermocapillary flow along with rising liquid film on the surface

Manuel J. GOMES, Ning MEI

期刊论文

State-of-the-art applications of machine learning in the life cycle of solid waste management

期刊论文

Simulation and experiments on a solid sorption combined cooling and power system driven by the exhaust

Peng GAO, Liwei WANG, Ruzhu WANG, Yang YU

期刊论文

Sulfur cycle as an electron mediator between carbon and nitrate in a constructed wetland microcosm

Wenrui Guo, Yue Wen, Yi Chen, Qi Zhou

期刊论文

Carbon emission impact on the operation of virtual power plant with combined heat and power system

Yu-hang XIA,Jun-yong LIU,Zheng-wen HUANG,Xu ZHANG

期刊论文

Life-cycle cost analysis of optimal timing of pavement preservation

Zilong WANG,Hao WANG

期刊论文