The present risk analysis model of engineering investment is built by fuzzy hierarchy approach under the assumption of maximizing the revenues of the project during its whole life cycle of operation. It can reasonably...The present risk analysis model of engineering investment is built by fuzzy hierarchy approach under the assumption of maximizing the revenues of the project during its whole life cycle of operation. It can reasonably be expressed by a system evaluation analysis. As a matter of fact, the system, aimed by its system goal can be modelled by a set of factors, constitutively structured by certain links between them, to form a factorial network chart, which represents the essentials of the system behaviours, the nodes of which represent the factors concerned. The weight distribution between factors located at the same level can be determined by the eigen-value problem of a 'pair comparison' relation matrix. The weight distribution of factors at each level is successively manipulated until the fuzzy synthetic risk assessment. As an example of risk analysis of engineering investment, a harbour construction project is presented for illustration.展开更多
Crude oil distillation is important in refining industry. Operating variables of distillation process have a critical effect on product output value and energy consumption. However, the objectives of minimum energy co...Crude oil distillation is important in refining industry. Operating variables of distillation process have a critical effect on product output value and energy consumption. However, the objectives of minimum energy consumption and maximum product output value do not coordinate with each other and do not lead to the maximum economic benefit of a refinery. In this paper, a systematic optimization approach is proposed for the maximum annual economic benefit of an existing crude oil distillation system, considering product output value and energy consumption simultaneously. A shortcut model in Aspen Plus is used to describe the crude oil distillation and the pinch analysis is adopted to identify the target of energy recovery. The optimization is a nonlinear programming problem and solved by stochastic algorithm of particle warm optimization.展开更多
Under the ambitious goal of carbon neutralization,photovoltaic(PV)-driven electrolytic hydrogen(PVEH)production is emerging as a promising approach to reduce carbon emission.Considering the intermittence and variabili...Under the ambitious goal of carbon neutralization,photovoltaic(PV)-driven electrolytic hydrogen(PVEH)production is emerging as a promising approach to reduce carbon emission.Considering the intermittence and variability of PV power generation,the deployment of battery energy storage can smoothen the power output.However,the investment cost of battery energy storage is pertinent to non-negligible expenses.Thus,the installation of energy-storage equipment in a PVEH system is a complex trade-off problem.The primary goals of this study are to compare the engineering economics of PVEH systems with and without energy storage,and to explore time nodes when the cost of the former scenario can compete with the latter by factoring the technology learning curve.The levelized cost of hydrogen(LCOH)is a widely used economic indicator.Represented by seven areas in seven regions of China,results show that the LCOH with and without energy storage is approximately 22.23 and 20.59 yuan/kg in 2020,respectively.In addition,as technology costs drop,the LCOH of a PVEH system with energy storage will be less than that without energy storage in 2030.展开更多
Beijing Review continues to publish edited excerpts of Why and How the CPC Works in China.Edited chapter six-How Could the CPC Make China the World’s Second Largest Economy-is as follows: When the 10-year "cultu...Beijing Review continues to publish edited excerpts of Why and How the CPC Works in China.Edited chapter six-How Could the CPC Make China the World’s Second Largest Economy-is as follows: When the 10-year "cultural revolution" (1966-76) finally came to an end in展开更多
文摘The present risk analysis model of engineering investment is built by fuzzy hierarchy approach under the assumption of maximizing the revenues of the project during its whole life cycle of operation. It can reasonably be expressed by a system evaluation analysis. As a matter of fact, the system, aimed by its system goal can be modelled by a set of factors, constitutively structured by certain links between them, to form a factorial network chart, which represents the essentials of the system behaviours, the nodes of which represent the factors concerned. The weight distribution between factors located at the same level can be determined by the eigen-value problem of a 'pair comparison' relation matrix. The weight distribution of factors at each level is successively manipulated until the fuzzy synthetic risk assessment. As an example of risk analysis of engineering investment, a harbour construction project is presented for illustration.
基金Supported by the National Natural Science Foundation of China(21176178)the State Key Laboratory of Chemical Engineering(SKL-Ch E-13B02)
文摘Crude oil distillation is important in refining industry. Operating variables of distillation process have a critical effect on product output value and energy consumption. However, the objectives of minimum energy consumption and maximum product output value do not coordinate with each other and do not lead to the maximum economic benefit of a refinery. In this paper, a systematic optimization approach is proposed for the maximum annual economic benefit of an existing crude oil distillation system, considering product output value and energy consumption simultaneously. A shortcut model in Aspen Plus is used to describe the crude oil distillation and the pinch analysis is adopted to identify the target of energy recovery. The optimization is a nonlinear programming problem and solved by stochastic algorithm of particle warm optimization.
基金the National Natural Science Foundation of China(Grant No.71772060)the State Key Laboratory of Power System Operation and Control(Grant No.SKLD22KM16)+1 种基金the Social Science Foundation of Beijing(Grant No.22JCC092)the Fundamental Research Funds for the Central Universities(Grant Nos.2021MS022 and 2021PT013).
文摘Under the ambitious goal of carbon neutralization,photovoltaic(PV)-driven electrolytic hydrogen(PVEH)production is emerging as a promising approach to reduce carbon emission.Considering the intermittence and variability of PV power generation,the deployment of battery energy storage can smoothen the power output.However,the investment cost of battery energy storage is pertinent to non-negligible expenses.Thus,the installation of energy-storage equipment in a PVEH system is a complex trade-off problem.The primary goals of this study are to compare the engineering economics of PVEH systems with and without energy storage,and to explore time nodes when the cost of the former scenario can compete with the latter by factoring the technology learning curve.The levelized cost of hydrogen(LCOH)is a widely used economic indicator.Represented by seven areas in seven regions of China,results show that the LCOH with and without energy storage is approximately 22.23 and 20.59 yuan/kg in 2020,respectively.In addition,as technology costs drop,the LCOH of a PVEH system with energy storage will be less than that without energy storage in 2030.
文摘Beijing Review continues to publish edited excerpts of Why and How the CPC Works in China.Edited chapter six-How Could the CPC Make China the World’s Second Largest Economy-is as follows: When the 10-year "cultural revolution" (1966-76) finally came to an end in
