In order to provide more grid space for the renewable energy power,the traditional coal-fired power unit should be operated flexibility,especially achieved the deep peak shaving capacity.In this paper,a new scheme usi...In order to provide more grid space for the renewable energy power,the traditional coal-fired power unit should be operated flexibility,especially achieved the deep peak shaving capacity.In this paper,a new scheme using the reheat steam extraction is proposed to further reduce the load far below 50%rated power.Two flexible operation modes of increasing power output mode and reducing fuel mode are proposed in heat discharging process.A 600 MW coal-fired power unit with 50%rated power is chosen as the research model.The results show that the power output is decreased from 300.03 MW to 210.07 MW when the extracted reheat steam flow rate is 270.70 t·h^(-1),which increases the deep peak shaving capacity by 15%rated power.The deep peak shaving time and the thermal efficiency are 7.63 h·d^(-1)and 36.91%respectively for the increasing power output mode,and they are 7.24 h·d^(-1)and 36.58%respectively for the reducing fuel mode.The increasing power output mode has the advantages of higher deep peak shaving time and the thermal efficiency,which is recommended as the preferred scheme for the flexible operation of the coal-fired power unit.展开更多
Increasing wind power integration and coal-fired unit retirements increases the strain on the power system’s spinning reserve and increases the pressure on peak regulation.With the ability to stock extra power genera...Increasing wind power integration and coal-fired unit retirements increases the strain on the power system’s spinning reserve and increases the pressure on peak regulation.With the ability to stock extra power generation and supply the peak load,the energy storage system(ESS)can alleviate the rising demand on the spinning reserve and play an increasingly important role in the power system.In this paper,a trilevel robust ESS planning model is proposed to accommodate uncertain wind power investment as well as coal-fired unit retirement.The upper-level of this model is to determine the planning scheme of ESSs,which iteratively takes the worst-case scenario of wind power investment and coal-fired unit retirement into consideration.The middle-level and lower-level of this model are to make the optimal daily economic dispatch under the worst-case realizations of uncertainties.We derive an equivalent reformulation of the proposed robust ESS planning model and solve it with a dual column-and-constraint generation algorithm.Case studies are conducted using the IEEE RTS-79 system.The results demonstrate the superiority of the proposed planning method in comparison with other methods.Furthermore,the effects of the capital cost of ESS,the expected proportion of wind power,and the uncertainty budget on the development of ESS are studied.Taking the uncertainties of unit retirement and wind power investment into consideration achieves a better trade-off between the ESS investment cost and the operational cost.展开更多
Coal-fired power is the main power source and the biggest contributor to energy conservation in the past several decades in China.It is generally believed that advanced technology should be counted on for energy conse...Coal-fired power is the main power source and the biggest contributor to energy conservation in the past several decades in China.It is generally believed that advanced technology should be counted on for energy conservation.However,a review of the decline in the national average net coal consumption rate(NCCR)of China's coal-fired power industry along with its development over the past few decades indicates that the upgradation of the national unit capacity structure(including installing advanced production and phasing out backward production)plays a more important role.A quantitative study on the effect of the unit capacity structure upgradation on the decline in the national average NCCR suggests that phasing out backward production is the leading factor for the decline in the NCCR in the past decade,followed by the new installation,whose sum contributes to approximately 80%of the decline in the national average NCCR.The new installation has an effective affecting period of about 8 years,during which it would gradually decline from a relatively high value.Since the effect of phasing out backward production may remain at a certain degree given a continual action of phasing out backward capacity,it is suggested that the organized action of phasing out backward production should be insisted on.展开更多
The energy-saving analytics of coal-fired power units in China is confronting new challenges especially with even more complicated system structure, higher working medium parameters, time-dependent varying operation c...The energy-saving analytics of coal-fired power units in China is confronting new challenges especially with even more complicated system structure, higher working medium parameters, time-dependent varying operation conditions and boundaries such as load rate, coal quality, ambient temperature and humidity. Compared with the traditional optimization of specific operating parameters, the idea of the energy-consumption benchmark state was proposed. The equivalent specific fuel consumption(ESFC) analytics was introduced to determine the energy-consumption benchmark state, with the minimum ESFC under varying operation boundaries. Models for the energy-consumption benchmark state were established, and the endogenous additional specific consumption(ASFC) and exogenous ASFC were calculated. By comparing the benchmark state with the actual state, the energy-saving tempospacial effect can be quantified. As a case study, the energy consumption model of a 1000 MW ultra supercritical power unit was built. The results show that system energy consumption can be mainly reduced by improving the performance of turbine subsystem. This nearly doubles the resultant by improving the boiler system. The energy saving effect of each component increases with the decrease of load and has a greater influence under a lower load rate. The heat and mass transfer process takes priority in energy saving diagnosis of related components and processes. This makes great reference for the design and operation optimization of coal-fired power units.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52076006)the Inner Mongolia Science and Technology Major Project(Grant No.2021ZD0036)。
文摘In order to provide more grid space for the renewable energy power,the traditional coal-fired power unit should be operated flexibility,especially achieved the deep peak shaving capacity.In this paper,a new scheme using the reheat steam extraction is proposed to further reduce the load far below 50%rated power.Two flexible operation modes of increasing power output mode and reducing fuel mode are proposed in heat discharging process.A 600 MW coal-fired power unit with 50%rated power is chosen as the research model.The results show that the power output is decreased from 300.03 MW to 210.07 MW when the extracted reheat steam flow rate is 270.70 t·h^(-1),which increases the deep peak shaving capacity by 15%rated power.The deep peak shaving time and the thermal efficiency are 7.63 h·d^(-1)and 36.91%respectively for the increasing power output mode,and they are 7.24 h·d^(-1)and 36.58%respectively for the reducing fuel mode.The increasing power output mode has the advantages of higher deep peak shaving time and the thermal efficiency,which is recommended as the preferred scheme for the flexible operation of the coal-fired power unit.
基金This work was supported by the National Key R&D Program of China(2016YFB0900100)the National Natural Science Foundation of China(51907123,51807116).
文摘Increasing wind power integration and coal-fired unit retirements increases the strain on the power system’s spinning reserve and increases the pressure on peak regulation.With the ability to stock extra power generation and supply the peak load,the energy storage system(ESS)can alleviate the rising demand on the spinning reserve and play an increasingly important role in the power system.In this paper,a trilevel robust ESS planning model is proposed to accommodate uncertain wind power investment as well as coal-fired unit retirement.The upper-level of this model is to determine the planning scheme of ESSs,which iteratively takes the worst-case scenario of wind power investment and coal-fired unit retirement into consideration.The middle-level and lower-level of this model are to make the optimal daily economic dispatch under the worst-case realizations of uncertainties.We derive an equivalent reformulation of the proposed robust ESS planning model and solve it with a dual column-and-constraint generation algorithm.Case studies are conducted using the IEEE RTS-79 system.The results demonstrate the superiority of the proposed planning method in comparison with other methods.Furthermore,the effects of the capital cost of ESS,the expected proportion of wind power,and the uncertainty budget on the development of ESS are studied.Taking the uncertainties of unit retirement and wind power investment into consideration achieves a better trade-off between the ESS investment cost and the operational cost.
基金China Postdoctoral Science Foundation (No.2017M620758)Special Funds of the National Natural Science Foundation of China(Grant No.L1522032)the Consulting Project of Chinese Academy of Engineering(No.2015-ZCQ-06).
文摘Coal-fired power is the main power source and the biggest contributor to energy conservation in the past several decades in China.It is generally believed that advanced technology should be counted on for energy conservation.However,a review of the decline in the national average net coal consumption rate(NCCR)of China's coal-fired power industry along with its development over the past few decades indicates that the upgradation of the national unit capacity structure(including installing advanced production and phasing out backward production)plays a more important role.A quantitative study on the effect of the unit capacity structure upgradation on the decline in the national average NCCR suggests that phasing out backward production is the leading factor for the decline in the NCCR in the past decade,followed by the new installation,whose sum contributes to approximately 80%of the decline in the national average NCCR.The new installation has an effective affecting period of about 8 years,during which it would gradually decline from a relatively high value.Since the effect of phasing out backward production may remain at a certain degree given a continual action of phasing out backward capacity,it is suggested that the organized action of phasing out backward production should be insisted on.
文摘The energy-saving analytics of coal-fired power units in China is confronting new challenges especially with even more complicated system structure, higher working medium parameters, time-dependent varying operation conditions and boundaries such as load rate, coal quality, ambient temperature and humidity. Compared with the traditional optimization of specific operating parameters, the idea of the energy-consumption benchmark state was proposed. The equivalent specific fuel consumption(ESFC) analytics was introduced to determine the energy-consumption benchmark state, with the minimum ESFC under varying operation boundaries. Models for the energy-consumption benchmark state were established, and the endogenous additional specific consumption(ASFC) and exogenous ASFC were calculated. By comparing the benchmark state with the actual state, the energy-saving tempospacial effect can be quantified. As a case study, the energy consumption model of a 1000 MW ultra supercritical power unit was built. The results show that system energy consumption can be mainly reduced by improving the performance of turbine subsystem. This nearly doubles the resultant by improving the boiler system. The energy saving effect of each component increases with the decrease of load and has a greater influence under a lower load rate. The heat and mass transfer process takes priority in energy saving diagnosis of related components and processes. This makes great reference for the design and operation optimization of coal-fired power units.
