The boundaries of a natural harbor or artificial harbor are very complex as far as its shape and reflection condition are concerned. The schemes available for solving wave diffraction in a harbor are not very accurate...The boundaries of a natural harbor or artificial harbor are very complex as far as its shape and reflection condition are concerned. The schemes available for solving wave diffraction in a harbor are not very accurate due to the simplification of realistic boundaries into a single jetty, a gap breakwater and a detached breakwater, neglecting the reflection effect of boundaries along the quays and the shore line whose shapes are rather irregular. Physical models turn to be quite helpful and valid in this case. In the present paper a mathematical model for wave diffraction in a harbor is introduced by using the singularity distribution method which can take into account the boundaries with arbitrary rate of reflection. The present model has been applied to the estimation of wave diffraction in the harbor basin of Guangdong Dayawan Nuclear Plant, and verifications with corresponding physical models are quite favorable.展开更多
The water level control system of steam generator in a pressurized water reactor of nuchear power plant plays an important role which effects the water level control of the steam generator are due the reverse dynamics...The water level control system of steam generator in a pressurized water reactor of nuchear power plant plays an important role which effects the water level control of the steam generator are due the reverse dynamics behavior,so the transient analysis of the steam generator should firstly solve their mathematical models.For determination of dynamic behavior and design and testing of the control system, a nonlinear math model is developed using one dimensional conservation equations of mass,momentum and energy of primary and secondary sides of the steam generator. The nonlinear model is verified with standard power plant data available in the references, then the steady states and transient calculations are performed for full power to 5% power reactor operation of the steam generator of Chinese Qinshan Nuclear Power Plant.展开更多
This study designs and proposes a method for evaluating the configuration of energy storage for integrated re-newable generation plants in the power spot market,which adopts a two-level optimization model of“system s...This study designs and proposes a method for evaluating the configuration of energy storage for integrated re-newable generation plants in the power spot market,which adopts a two-level optimization model of“system simulation+plant optimization”.The first step is“system simulation”which is using the power market simu-lation model to obtain the initial nodal marginal price and curtailment of the integrated renewable generation plant.The second step is“plant optimization”which is using the operation optimization model of the integrated renewable generation plant to optimize the charge-discharge operation of energy storage.In the third step,“sys-tem simulation”is conducted again,and the combined power of renewable and energy storage inside the plant is brought into the system model and simulated again for 8,760 h of power market year-round to quantify and compare the power generation and revenue of the integrated renewable generation plant after applying energy storage.In the case analysis of the provincial power spot market,an empirical analysis of a 1 GW wind-solar-storage integrated generation plant was conducted.The results show that the economic benefit of energy storage is approximately proportional to its capacity and that there is a slowdown in the growth of economic benefits when the capacity is too large.In the case that the investment benefit of energy storage only considers the in-come of electric energy-related incomes and does not consider the income of capacity mechanism and auxiliary services,the income of energy storage cannot fulfill the economic requirements of energy storage investment.展开更多
China Energy’s National Institute of Clean-and-Low-Carbon Energy(NICE)is developing a Power Plant Smart Management(PPSM)platform that employs digital-twin technology to undertake techno-economic modelling analysis on...China Energy’s National Institute of Clean-and-Low-Carbon Energy(NICE)is developing a Power Plant Smart Management(PPSM)platform that employs digital-twin technology to undertake techno-economic modelling analysis on China Energy’s existing coal-fired power-plant units and explore cost-effective solutions to improve those plant units’thermal efficiencies and operating performance.This paper presents a case study of PPSM on a 320-MWe coal-fired thermal power-plant unit,demonstrating how the digital-twin technology was employed to explore and analyse optimization solutions.Various optimization solutions and their cost-effectiveness were assessed using the digital-twin-modelling analysis;the results indicated the optimization solutions are expected to improve the plant unit’s operating efficiency and reduce its current electricity-generation coal consumption by up to 3.5 g/kWh standard coal equivalent(sce),worth annual fuel-cost savings of approximately 4 million RMB for a single unit or 8 million RMB for the two identical 320-MWe units that the power plant currently operates.The digital twin was also employed to assess the power-plant unit’s operating economics during both summer and winter.In summer,when the unit operates in electricity-generation-only mode,the unit’s operating thermal efficiency could drop by up to 6%points following the grid demand of load changes from 100%maximum continuous rating(MCR)down to 30% MCR,resulting in an~45 RMB/MWh increase of electricity-generation cost.In winter,when the unit operates in combined heat and power(CHP)cogeneration mode,for the same boiler load,the CHP operation increases the plant unit’s operating profit with increasing district-heating duty,although the relative profit gain from the CHP cogeneration could start to decrease when the district-heating steam-extraction flow increases to a certain point that varies depending on the market prices of heat and electricity,while the fuel cost was found to be equivalent to~50% of the unit’s total CHP income cogenerated from its electricity and district heat outputs.展开更多
文摘The boundaries of a natural harbor or artificial harbor are very complex as far as its shape and reflection condition are concerned. The schemes available for solving wave diffraction in a harbor are not very accurate due to the simplification of realistic boundaries into a single jetty, a gap breakwater and a detached breakwater, neglecting the reflection effect of boundaries along the quays and the shore line whose shapes are rather irregular. Physical models turn to be quite helpful and valid in this case. In the present paper a mathematical model for wave diffraction in a harbor is introduced by using the singularity distribution method which can take into account the boundaries with arbitrary rate of reflection. The present model has been applied to the estimation of wave diffraction in the harbor basin of Guangdong Dayawan Nuclear Plant, and verifications with corresponding physical models are quite favorable.
文摘The water level control system of steam generator in a pressurized water reactor of nuchear power plant plays an important role which effects the water level control of the steam generator are due the reverse dynamics behavior,so the transient analysis of the steam generator should firstly solve their mathematical models.For determination of dynamic behavior and design and testing of the control system, a nonlinear math model is developed using one dimensional conservation equations of mass,momentum and energy of primary and secondary sides of the steam generator. The nonlinear model is verified with standard power plant data available in the references, then the steady states and transient calculations are performed for full power to 5% power reactor operation of the steam generator of Chinese Qinshan Nuclear Power Plant.
基金funded by the China Energy Investment Cor-poration under the program“Simulation of energy storage application scenarios in China and research on development strategy of China En-ergy Investment Corporation”(Grant No.:GJNY-21-143).
文摘This study designs and proposes a method for evaluating the configuration of energy storage for integrated re-newable generation plants in the power spot market,which adopts a two-level optimization model of“system simulation+plant optimization”.The first step is“system simulation”which is using the power market simu-lation model to obtain the initial nodal marginal price and curtailment of the integrated renewable generation plant.The second step is“plant optimization”which is using the operation optimization model of the integrated renewable generation plant to optimize the charge-discharge operation of energy storage.In the third step,“sys-tem simulation”is conducted again,and the combined power of renewable and energy storage inside the plant is brought into the system model and simulated again for 8,760 h of power market year-round to quantify and compare the power generation and revenue of the integrated renewable generation plant after applying energy storage.In the case analysis of the provincial power spot market,an empirical analysis of a 1 GW wind-solar-storage integrated generation plant was conducted.The results show that the economic benefit of energy storage is approximately proportional to its capacity and that there is a slowdown in the growth of economic benefits when the capacity is too large.In the case that the investment benefit of energy storage only considers the in-come of electric energy-related incomes and does not consider the income of capacity mechanism and auxiliary services,the income of energy storage cannot fulfill the economic requirements of energy storage investment.
文摘China Energy’s National Institute of Clean-and-Low-Carbon Energy(NICE)is developing a Power Plant Smart Management(PPSM)platform that employs digital-twin technology to undertake techno-economic modelling analysis on China Energy’s existing coal-fired power-plant units and explore cost-effective solutions to improve those plant units’thermal efficiencies and operating performance.This paper presents a case study of PPSM on a 320-MWe coal-fired thermal power-plant unit,demonstrating how the digital-twin technology was employed to explore and analyse optimization solutions.Various optimization solutions and their cost-effectiveness were assessed using the digital-twin-modelling analysis;the results indicated the optimization solutions are expected to improve the plant unit’s operating efficiency and reduce its current electricity-generation coal consumption by up to 3.5 g/kWh standard coal equivalent(sce),worth annual fuel-cost savings of approximately 4 million RMB for a single unit or 8 million RMB for the two identical 320-MWe units that the power plant currently operates.The digital twin was also employed to assess the power-plant unit’s operating economics during both summer and winter.In summer,when the unit operates in electricity-generation-only mode,the unit’s operating thermal efficiency could drop by up to 6%points following the grid demand of load changes from 100%maximum continuous rating(MCR)down to 30% MCR,resulting in an~45 RMB/MWh increase of electricity-generation cost.In winter,when the unit operates in combined heat and power(CHP)cogeneration mode,for the same boiler load,the CHP operation increases the plant unit’s operating profit with increasing district-heating duty,although the relative profit gain from the CHP cogeneration could start to decrease when the district-heating steam-extraction flow increases to a certain point that varies depending on the market prices of heat and electricity,while the fuel cost was found to be equivalent to~50% of the unit’s total CHP income cogenerated from its electricity and district heat outputs.
