Water sector planning and policy making in arid and semi-arid regions are challenging because many drivers and decision criteria require consideration. In this study, a multi-period mixed -integer linear programming m...
详细信息
Water sector planning and policy making in arid and semi-arid regions are challenging because many drivers and decision criteria require consideration. In this study, a multi-period mixed -integer linear programming model was developed to integrate and economically evaluate water management options for water supply in arid regions. The applicability of the proposed approach was demonstrated through a case study in the Emirate of Abu Dhabi (EAD), United Arab Emirates. The model was programmed in general algebraic modeling system (GAMS) and solved using the Cplex solver. The model determined the optimal economic and environmental costs, capacity expansion of treatment plants and water transmission systems, and other environmental aspects including the carbon footprint and brine discharge. Results show that the capacity contribution of reverse osmosis for desalination is expected to increase from 5.1% in 2021 to 18.1% in 2050. Based on the model's results for the case study, it was concluded that even with moderate consideration of environmental aspects, desalination plants in the EAD need a major technology transformation from thermal desalination to reverse osmosis The proposed model is proved to be effective for integrated water resources management and infrastructure planning in the EAD, and has the potential for effective application in other arid or semi-arid countries.
Predictive energy management systems (EMS) enable the optimization of industrial energy supply systems (ESS) without cost-intensive structural changes. Despite intensive research on EMS, few publications address indus...
详细信息
Predictive energy management systems (EMS) enable the optimization of industrial energy supply systems (ESS) without cost-intensive structural changes. Despite intensive research on EMS, few publications address industrial applications - and even fewer address practical experiments with industrial EMS in physical laboratory environments. This paper describes the design and usage of a test rig emulating an industrial ESS including temporarily available heat recovery systems and batch-type heat demands. In addition, the performance of a recently proposed modular two-layer EMS is assessed on this test rig. The experimental setup consists of a heat pump, an electric boiler, an instantaneous water heater, and a thermal energy storage system. To emulate an industrial ESS current values of volatile energy prices, emissions footprint and industrial measurement data of heat loads are used. The experiments validate that the test rig can emulate an industrial ESS. Further, the results show that the EMS makes optimal use of the laboratory ESS and takes full advantage of temporarily available energy sources. Bottlenecks in heat supply were avoided, and for this specific setup energy cost-reductions of 5-12% and CO2-reductions of 9-42% were achieved compared to a hysteresis controller.
Reservoir flood control operation is an important and effective measure for avoiding or reducing flood disasters. Considering that reservoir operation is a control process that essentially manages the spillway gates t...
详细信息
Reservoir flood control operation is an important and effective measure for avoiding or reducing flood disasters. Considering that reservoir operation is a control process that essentially manages the spillway gates to increase or decrease the amount of released water, this paper focuses on studying the reservoir flood control operation which considers spillway gate scheduling. Minimizing the peak outflow from the reservoir is adopted as the optimization objective to protect downstream areas from flood disasters. In addition to the conventional reservoir constraints, the operation constraints of individual spillway gates and the influence of the reservoir forebay water level and opening degree on the gates' discharge capacity are also well considered to obtain precise scheduling. The nonlinear factors, especially the objective function in the form of maximin, the three-dimensional water discharge curves, and the rules for the opening and closing sequence of the spillway gates, are linearized through several strategies. The original nonlinear and non-convex model is then converted into a standard mixed-integerlinearprogramming (MILP) formulation. The results for the real-world case study indicate that: 1) the proposed model is believed to be computationally efficient with a calculation time of about 30 min;2) for the flood events with return periods of 10 years and 100 years, the flood peaks are reduced from 4160 m3/s to 3681 m3/s and from 11007 m3/s to 9293 m3/s, representing decreases of 11.5 % and 15.6 %, respectively. The outflow curves become more stable, demonstrating that the flood control pressure on the downstream had been relieved after optimization;3) the proposed model can produce more realistic and executable flood control operation scheduling compared with the conventional optimization model without considering spillway gate scheduling. These research findings can provide an effective reference for both the operators of reservoirs and researchers in t
暂无评论