One of the most important issues in storage and transport processes is the formation of unit loads. Our main goal is to investigate the homogenization of unit load formation cases. We provide a model involving the maj...One of the most important issues in storage and transport processes is the formation of unit loads. Our main goal is to investigate the homogenization of unit load formation cases. We provide a model involving the major factors and parameters for the optimal selection of the unit load formations. Objective functions and constraints related to the basic tasks are formulated. We give a method for the selection of the optimal unit load formation equipment for a given number of products under given constraints.展开更多
Northern China has rich wind power and photovoltaic renewable resources. Combined Heat and Power (CHP) Units to meet the load demand and limit its peaking capacity in winter, to a certain extent, it results in structu...Northern China has rich wind power and photovoltaic renewable resources. Combined Heat and Power (CHP) Units to meet the load demand and limit its peaking capacity in winter, to a certain extent, it results in structural problems of wind-solar power and thermoelectric. To solve these problems, this paper proposes a plurality of units together to ensure supply of heat load on the premise, by building a thermoelectric power peaking considering thermal load unit group dynamic scheduling model, to achieve the potential of different thermoelectric properties peaking units of the excavation. Simulation examples show, if the unit group exists obvious relationship thermoelectric individual differences, the thermal load dynamic scheduling can be more significantly improved overall performance peaking unit group, effectively increase clean energy consumptive.展开更多
The anti-overturning ability and structure safety of jack-up unit in in-place condition are often affected by environment loads, especially wind load. According to the MODU rule, the projected area method is used for ...The anti-overturning ability and structure safety of jack-up unit in in-place condition are often affected by environment loads, especially wind load. According to the MODU rule, the projected area method is used for calculating the wind load. However, the calculated results are conservative and not good for structure optimization design. In this paper, a 400 ft jack-up is studied as an example. Based on the wind tunnel test and numerical simulation method, some key points of wind load calculation, such as shielding effect, lift effect and shape coefficient of component, are discussed. The study shows that the points mentioned above, which are ignored in the MODU rule calculation, result in the conservative result.展开更多
The hydro unit economic load dispatch （ELD） is of great importance in energy conservation and emission reduction. Dynamic programming （DP） and genetic algorithm （GA） are two representative algorithms for solving...The hydro unit economic load dispatch （ELD） is of great importance in energy conservation and emission reduction. Dynamic programming （DP） and genetic algorithm （GA） are two representative algorithms for solving ELD problems. The goal of this study was to examine the performance of DP and GA while they were applied to ELD. We established numerical experiments to conduct performance comparisons between DP and GA with two given schemes. The schemes included comparing the CPU time of the algorithms when they had the same solution quality, and comparing the solution quality when they had the same CPU time. The numerical experiments were applied to the Three Gorges Reservoir in China, which is equipped with 26 hydro generation units. We found the relation between the performance of algorithms and the number of units through experiments. Results show that GA is adept at searching for optimal solutions in low-dimensional cases. In some cases, such as with a number of units of less than 10, GA＇s performance is superior to that of a coarse-grid DP. However, GA loses its superiority in high-dimensional cases. DP is powerful in obtaining stable and high-quality solutions. Its performance can be maintained even while searching over a large solution space. Nevertheless, due to its exhaustive enumerating nature, it costs excess time in low-dimensional cases.展开更多
In this paper, a multiple population genetic algorithm (MPGA) is proposed to solve the problem of optimal load dispatch of gas turbine generation units. By introducing multiple populations on the basis of Standard Gen...In this paper, a multiple population genetic algorithm (MPGA) is proposed to solve the problem of optimal load dispatch of gas turbine generation units. By introducing multiple populations on the basis of Standard Genetic Algorithm (SGA), connecting each population through immigrant operator and preserving the best individuals of every generation through elite strategy, MPGA can enhance the efficiency in obtaining the global optimal solution. In this paper, MPGA is applied to optimize the load dispatch of 3×390MW gas turbine units. The results of MPGA calculation are compared with that of equal micro incremental method and AGC instruction. MPGA shows the best performance of optimization under different load conditions. The amount of saved gas consumption in the calculation is up to 2337.45m3N/h, which indicates that the load dispatch optimization of gas turbine units via MPGA approach can be effective.展开更多
In this paper, three rock types including Sandstone, Mudstone, and Crystalline Gypsum were part of a laboratory study conducted to develop a dataset for predicting the unconfined compressive strength of UAE intact sed...In this paper, three rock types including Sandstone, Mudstone, and Crystalline Gypsum were part of a laboratory study conducted to develop a dataset for predicting the unconfined compressive strength of UAE intact sedimentary rock specimens. Four hundred nineteen rock samples from various areas along the coastal region of the UAE were collected and tested for the development of this dataset and evaluation of models. From the statistical analysis of the data, regression equations were established among rock parameters and correlations were expressed and compared by the ones proposed in literature.展开更多
Both the modeling and the load regulation capacity prediction of a supercritical power plant are investigated in this paper. Firstly, an indirect identification method based on subspace identification method is propos...Both the modeling and the load regulation capacity prediction of a supercritical power plant are investigated in this paper. Firstly, an indirect identification method based on subspace identification method is proposed. The obtained identification model is verified by the actual operation data and the dynamic characteristics of the system are well reproduced. Secondly, the model is used to predict the load regulation capacity of thermal power unit. The power, main steam pressure, main steam temperature and other parameters are simulated respectively when the unit load is going up and down. Under the actual constraints, the load regulation capacity of thermal power unit can be predicted quickly.展开更多
The aim of this study was to determine the unit load of NPS （non-point source） pollutants including organic variables such as BOD （biochemical oxygen demand）, COD （chemical oxygen demand） and DOC （dissolved org...The aim of this study was to determine the unit load of NPS （non-point source） pollutants including organic variables such as BOD （biochemical oxygen demand）, COD （chemical oxygen demand） and DOC （dissolved organic carbon）, nitrogen and phosphorus constituents, and suspended solids （SS） and their event mean concentration （EMC） of runoff flows from a water-shed of mixed forest land use by intensive field experiments. Field monitoring for continuous measurements of rainfall, flow, and water quality was conducted over 12 storm events during 2008-2009 using automated and manual sampling methods. The EMCs of individual runoff event were estimated for each water quality constituent based on the flow rate and concentration data of runoff discharge. The average EMCs of BOD, COD, DOC, SS, TN （total nitrogen）, NH4^＋-N, NO3^--N, TP （total phosphorus）, PO4^3-P from the mixed forest land were 1.794, 3.498, 1.462, 10.269, 0.862, 0.044, 0.634, 0.034, and 0.005 mg/L, respectively. The annual unit loads of BOD, COD, DOC, SS, TN, NH4^＋-N, NO3^--N, TP and PO4^3--P were estimated as 66.9, 133.2, 55.5, 429.8, 36.5, 1.6, 26.9, 1.3 and 0.1 kg/（ha·yr）, respectively. In addition, affecting parameters on the EMCs were investigated by statistic analysis of the field data. As a result, significant correlations with precipitation, rainfall intensity, and total runoff flows were found in most constituents.展开更多
【目的】双碳目标下,为加速火电机组从主力型电源向提供调峰调频服务的辅助型电源角色转型,提升机组的负荷响应能力至关重要。传统控制方法在火电机组大范围变负荷运行过程中,容易出现响应不及时、稳态精度差、计算量大等问题。【方法...【目的】双碳目标下,为加速火电机组从主力型电源向提供调峰调频服务的辅助型电源角色转型,提升机组的负荷响应能力至关重要。传统控制方法在火电机组大范围变负荷运行过程中,容易出现响应不及时、稳态精度差、计算量大等问题。【方法】本文以某1 000 MW超超临界火电机组协调控制系统为研究对象,提出了一种基于Koopman算子的模型预测控制(Koopman model predictive control,KMPC)方法。该方法采用4阶龙格库塔法离散化原非线性系统获取数据集,通过扩展动态模态分解法有限维近似Koopman算子构建机组高维线性近似模型,并基于该模型预测系统未来动态,引入滚动时域优化策略,综合考虑控制约束、控制目标和性能指标等约束条件,设计超超临界火电机组的模型预测控制算法。以局部线性MPC(locallinear model predictive control,LMPC)为基准对比算法,通过仿真实验验证本文所提出的KMPC算法的有效性。【结果】研究表明,对应于机组的主蒸汽压力、分离器蒸汽焓值、汽轮机发电功率,(1)在连续阶跃升负荷仿真实验中高维近似系统与原非线性系统输出量相对均方根误差分别为1.00%,0.40%和0.36%;(2)标称工况下,KMPC算法在升负荷实验中输出量的时间加权绝对误差积分(integral of time-weighted absolute error,ITAE)相较LMPC分别减少了46.67%、48.66%和21.46%;(3)在模型失配工况下,相较于LMPC算法,KMPC算法在升负荷实验中输出量的ITAE分别减少了19.57%、22.45%和30.94%。【结论】基于Koopman算子构建的高维线性近似模型可较为精准捕捉原系统非线性动力学特征;与LMPC算法相比,KMPC算法在机组大范围变负荷运行过程中响应更加及时且稳态误差更小,同时表现出更强的鲁棒性,有利于机组现场运行。展开更多
文摘One of the most important issues in storage and transport processes is the formation of unit loads. Our main goal is to investigate the homogenization of unit load formation cases. We provide a model involving the major factors and parameters for the optimal selection of the unit load formations. Objective functions and constraints related to the basic tasks are formulated. We give a method for the selection of the optimal unit load formation equipment for a given number of products under given constraints.
文摘Northern China has rich wind power and photovoltaic renewable resources. Combined Heat and Power (CHP) Units to meet the load demand and limit its peaking capacity in winter, to a certain extent, it results in structural problems of wind-solar power and thermoelectric. To solve these problems, this paper proposes a plurality of units together to ensure supply of heat load on the premise, by building a thermoelectric power peaking considering thermal load unit group dynamic scheduling model, to achieve the potential of different thermoelectric properties peaking units of the excavation. Simulation examples show, if the unit group exists obvious relationship thermoelectric individual differences, the thermal load dynamic scheduling can be more significantly improved overall performance peaking unit group, effectively increase clean energy consumptive.
基金supported by the National Natural Science Foundation of China(Grant No.51079034)the Fundamental Research Funds for the Central Universities(Grant No.HEUCFR1003)
文摘The anti-overturning ability and structure safety of jack-up unit in in-place condition are often affected by environment loads, especially wind load. According to the MODU rule, the projected area method is used for calculating the wind load. However, the calculated results are conservative and not good for structure optimization design. In this paper, a 400 ft jack-up is studied as an example. Based on the wind tunnel test and numerical simulation method, some key points of wind load calculation, such as shielding effect, lift effect and shape coefficient of component, are discussed. The study shows that the points mentioned above, which are ignored in the MODU rule calculation, result in the conservative result.
基金supported by the National Basic Research Program of China(973 Program,Grant No.2013CB036406)the National Natural Science Foundation of China(Grant No.51179044)the Research Innovation Program for College Graduates in Jiangsu Province of China(Grant No.CXZZ12-0242)
文摘The hydro unit economic load dispatch （ELD） is of great importance in energy conservation and emission reduction. Dynamic programming （DP） and genetic algorithm （GA） are two representative algorithms for solving ELD problems. The goal of this study was to examine the performance of DP and GA while they were applied to ELD. We established numerical experiments to conduct performance comparisons between DP and GA with two given schemes. The schemes included comparing the CPU time of the algorithms when they had the same solution quality, and comparing the solution quality when they had the same CPU time. The numerical experiments were applied to the Three Gorges Reservoir in China, which is equipped with 26 hydro generation units. We found the relation between the performance of algorithms and the number of units through experiments. Results show that GA is adept at searching for optimal solutions in low-dimensional cases. In some cases, such as with a number of units of less than 10, GA＇s performance is superior to that of a coarse-grid DP. However, GA loses its superiority in high-dimensional cases. DP is powerful in obtaining stable and high-quality solutions. Its performance can be maintained even while searching over a large solution space. Nevertheless, due to its exhaustive enumerating nature, it costs excess time in low-dimensional cases.
文摘In this paper, a multiple population genetic algorithm (MPGA) is proposed to solve the problem of optimal load dispatch of gas turbine generation units. By introducing multiple populations on the basis of Standard Genetic Algorithm (SGA), connecting each population through immigrant operator and preserving the best individuals of every generation through elite strategy, MPGA can enhance the efficiency in obtaining the global optimal solution. In this paper, MPGA is applied to optimize the load dispatch of 3×390MW gas turbine units. The results of MPGA calculation are compared with that of equal micro incremental method and AGC instruction. MPGA shows the best performance of optimization under different load conditions. The amount of saved gas consumption in the calculation is up to 2337.45m3N/h, which indicates that the load dispatch optimization of gas turbine units via MPGA approach can be effective.
文摘In this paper, three rock types including Sandstone, Mudstone, and Crystalline Gypsum were part of a laboratory study conducted to develop a dataset for predicting the unconfined compressive strength of UAE intact sedimentary rock specimens. Four hundred nineteen rock samples from various areas along the coastal region of the UAE were collected and tested for the development of this dataset and evaluation of models. From the statistical analysis of the data, regression equations were established among rock parameters and correlations were expressed and compared by the ones proposed in literature.
文摘Both the modeling and the load regulation capacity prediction of a supercritical power plant are investigated in this paper. Firstly, an indirect identification method based on subspace identification method is proposed. The obtained identification model is verified by the actual operation data and the dynamic characteristics of the system are well reproduced. Secondly, the model is used to predict the load regulation capacity of thermal power unit. The power, main steam pressure, main steam temperature and other parameters are simulated respectively when the unit load is going up and down. Under the actual constraints, the load regulation capacity of thermal power unit can be predicted quickly.
基金supported by the National Institute of Environmental Research,Korea
文摘The aim of this study was to determine the unit load of NPS （non-point source） pollutants including organic variables such as BOD （biochemical oxygen demand）, COD （chemical oxygen demand） and DOC （dissolved organic carbon）, nitrogen and phosphorus constituents, and suspended solids （SS） and their event mean concentration （EMC） of runoff flows from a water-shed of mixed forest land use by intensive field experiments. Field monitoring for continuous measurements of rainfall, flow, and water quality was conducted over 12 storm events during 2008-2009 using automated and manual sampling methods. The EMCs of individual runoff event were estimated for each water quality constituent based on the flow rate and concentration data of runoff discharge. The average EMCs of BOD, COD, DOC, SS, TN （total nitrogen）, NH4^＋-N, NO3^--N, TP （total phosphorus）, PO4^3-P from the mixed forest land were 1.794, 3.498, 1.462, 10.269, 0.862, 0.044, 0.634, 0.034, and 0.005 mg/L, respectively. The annual unit loads of BOD, COD, DOC, SS, TN, NH4^＋-N, NO3^--N, TP and PO4^3--P were estimated as 66.9, 133.2, 55.5, 429.8, 36.5, 1.6, 26.9, 1.3 and 0.1 kg/（ha·yr）, respectively. In addition, affecting parameters on the EMCs were investigated by statistic analysis of the field data. As a result, significant correlations with precipitation, rainfall intensity, and total runoff flows were found in most constituents.
文摘【目的】双碳目标下,为加速火电机组从主力型电源向提供调峰调频服务的辅助型电源角色转型,提升机组的负荷响应能力至关重要。传统控制方法在火电机组大范围变负荷运行过程中,容易出现响应不及时、稳态精度差、计算量大等问题。【方法】本文以某1 000 MW超超临界火电机组协调控制系统为研究对象,提出了一种基于Koopman算子的模型预测控制(Koopman model predictive control,KMPC)方法。该方法采用4阶龙格库塔法离散化原非线性系统获取数据集,通过扩展动态模态分解法有限维近似Koopman算子构建机组高维线性近似模型,并基于该模型预测系统未来动态,引入滚动时域优化策略,综合考虑控制约束、控制目标和性能指标等约束条件,设计超超临界火电机组的模型预测控制算法。以局部线性MPC(locallinear model predictive control,LMPC)为基准对比算法,通过仿真实验验证本文所提出的KMPC算法的有效性。【结果】研究表明,对应于机组的主蒸汽压力、分离器蒸汽焓值、汽轮机发电功率,(1)在连续阶跃升负荷仿真实验中高维近似系统与原非线性系统输出量相对均方根误差分别为1.00%,0.40%和0.36%;(2)标称工况下,KMPC算法在升负荷实验中输出量的时间加权绝对误差积分(integral of time-weighted absolute error,ITAE)相较LMPC分别减少了46.67%、48.66%和21.46%;(3)在模型失配工况下,相较于LMPC算法,KMPC算法在升负荷实验中输出量的ITAE分别减少了19.57%、22.45%和30.94%。【结论】基于Koopman算子构建的高维线性近似模型可较为精准捕捉原系统非线性动力学特征;与LMPC算法相比,KMPC算法在机组大范围变负荷运行过程中响应更加及时且稳态误差更小,同时表现出更强的鲁棒性,有利于机组现场运行。
