共查询到20条相似文献，搜索用时 15 毫秒
1.
Johannes Schmidt Sylvain Leduc Erik Dotzauer Georg Kindermann Erwin Schmid 《国际能源研究杂志》2010,34(11):970-985
Combined heat and power (CHP) plants fired by forest wood can significantly contribute to attaining the target of increasing the share of renewable energy production. However, the spatial distribution of biomass supply and of heat demand limits the potentials of CHP production. This article assesses CHP potentials using a mixed integer programming model that optimizes locations of bioenergy plants. Investment costs of district heating infrastructure are modeled as a function of heat demand densities, which can differ substantially. Gasification of biomass in a combined cycle process is assumed as production technology. Some model parameters have a broad range according to a literature review. Monte‐Carlo simulations have therefore been performed to account for model parameter uncertainty in our analysis. The model is applied to assess CHP potentials in Austria. Optimal locations of plants are clustered around big cities in the east of the country. At current power prices, biomass‐based CHP production allows producing around 3% of the total energy demand in Austria. Yet, the heat utilization decreases when CHP production increases due to limited heat demand that is suitable for district heating. Production potentials are most sensitive to biomass costs and power prices. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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系统负荷作为综合能源系统的约束条件,常以单个典型日加以表征,这难以描述实际负荷波动性与随机性的特点。本文构建了计及碳交易与需求响应的多典型日优化模型。通过引入谱聚类算法获得多个典型日数据,在表征原始负荷数据波动性与随机性的同时,也基于负荷数据构成实现了数据分类,并以负荷构成为基础分别建立优化模型,引入阶梯型碳交易机制与需求响应机制,在Python语言下调用Gurobi求解器完成模型求解仿真,在此基础上对阶梯型碳交易参数的变化开展研究。结果表明,本文提出的优化模型可很好地针对全年不同的负荷特征实现灵活调度,在兼顾经济性与环保性的同时有利于清洁机组出力。 相似文献
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There has been a growing interest in utilizing forest biomass for energy generation in district heating systems to reduce dependence on fossil fuels. However, variability in forest biomass availability and quality over time and its complex and costly supply chain have made investments in forest biomass energy generation projects less attractive. In this paper, a linear programming model is developed to minimize the delivery cost of forest biomass to the gate of heating plants and determine the optimal monthly flow of biomass to the plants. The model has a 1‐year planning horizon with monthly time steps. It determines (1) the amount of woodchips that should be transported to the plants from supply sources directly and through the terminal storages, (2) the amount of biomass that should be stored at supply sources and at terminal storages, and (3) the amount of biomass that should be chipped at supply sources and at terminal storages. The model was applied to a potential district heating system in Williams Lake, BC, Canada. The results of the optimization model indicated that it would not be economical to carry out the chipping process at the terminal storage. Biomass should be chipped at supply sources, and woodchips should be sent to the terminal storage and/or directly to the plant. Of the total optimum annual flow of woodchips to the plant, 90% is transported directly, while 10% is transported to the plant via the terminal storage. It would cost $43.38 Odt?1 to deliver forest biomass to the plant. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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This paper presents the results of thermodynamics modelling studies of a 2 kW (e) biomass-fired CHP system with organic Rankine cycle (ORC). Three environmentally friendly refrigerants, namely HFE7000, HFE7100 and n-pentane, have been selected as the ORC fluids. The thermodynamic properties of the selected ORC fluids which have been predicted by commercial software (EES) are used to predict the thermal efficiency of ORC. The results of modelling show that under the simulated conditions (1) the ORC thermal efficiency with any selected ORC fluid is well below (roughly about 60% of) the Carnot cycle efficiency; the ORC efficiency depends on not only the modelling conditions but also the ORC fluid – the highest predicted ORC efficiency is 16.6%; the predicted ORC efficiency follows the following order: n-pentane > HFE7000 > HFE7100 (2) both superheating and sub-cooling are detrimental to the ORC efficiency (3) the electrical efficiency of the CHP system with the selected ORC fluids is predicted to be within the range of 7.5%–13.5%, mainly depending on the hot water temperature of the biomass boiler and the ORC condenser cooling water temperature as well as the ORC fluid, and corresponding to about 1.5 kW and 2.71 kW electricity output (4) the overall CHP efficiency of the CHP system is in the order of 80% for all three ORC fluids although the amount and quality of heating supplied by the CHP system depend on the ORC fluid selected and the modelling conditions. 相似文献
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Dag Henning 《国际能源研究杂志》1998,22(8):691-713
The energy-system optimization model MODEST is described, especially heat storage and electricity load management. Linear programming is used for minimization of capital and operation costs. MODEST may be used to find the optimal investments and when to make them. The period under study can be divided into several linked subperiods which may consist of an arbitrary number of years. MODEST is here applied to a municipal electricity and district-heating system during three five-year periods. Each year is divided into three seasons. Demand peaks, as well as weekly and diurnal variations of, for example, costs are considered. The electricity demand is divided into the three sectors households, industries, and service. The electricity demand may be reduced by energy conservation, replacement of electric heating and load management. The profitability of load management, as well as cogeneration with and without heat storage at different prices of purchased power is calculated. At traditional Swedish electricity prices, the local utility should build a woodchips-fired steam-cycle CHP (combined heat and power) plant. Consumers would find it beneficial to reduce their electricity use by conservation and switching from electric heating to oil and biofuel. If just marginal power production costs are paid, the utility should introduce biomass-fired heat-only boilers instead. Electricity conservation is smaller at these lower prices. Load management is mainly profitable at the first price scheme which includes output-power-related charges. The heat storage should be used threefold: to cover demand peaks, as well as to enable increased CHP output when it is limited by the heat demand or to run heat pumps at cheap night electricity instead of in the daytime. © 1998 John Wiley & Sons, Ltd. 相似文献
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为了降低热电联产系统能量调度算法计算的复杂度,减少计算时间,提出了一种基于If-Then-Else规则的热电联产系统能量调度方法。通过引入逻辑变量来描述设备的启停状态和工作模式,建立混合逻辑动态模型,在模型预测控制的框架下,根据实时电价以及本地能源、电力负荷和热力负荷的预测结果,为模型中的二元决策变量赋值,从而将模型中的混合整数线性规划问题转化为线性规划问题。最后,通过仿真将本文提出的方法和混合整数线性规划方法进行比较,结果表明,本文所采用的方法在性能上几乎没有损失,平均计算时间降低65%。 相似文献
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《Biofuels, Bioproducts and Biorefining》2018,12(4):624-648
This research develops an optimization model to describe the tradeoff among blend components in the least‐cost biomass blend, based on resource availability, quality requirements, and logistics cost for a biochemical conversion. A mixed‐integer linear programming model is developed to determine the least‐cost blend from a set of candidate feedstocks. A case study – based on a biorefinery located in western Kansas that uses three‐pass corn stover, two‐pass corn stover, switchgrass, miscanthus, and municipal solid waste fractions to meet biochemical conversion specifications and feedstock demand – shows that the delivered cost of an optimal blend that meets carbohydrate and ash specifications is 12.12% higher than the delivered cost of optimal blend that meets a carbohydrate specification only. The results indicate that a least‐cost blend that meets both carbohydrate and ash specifications consists of miscanthus (48.2%) and switchgrass (29.4%) whereas the least‐cost blend meeting carbohydrate specification only comprises three‐pass corn stover (55.4%) and two‐pass corn stover (20.4%). An optimal blend uses a low‐cost municipal solid waste fraction in all cases, implying that blending could be a potential strategy to reduce delivered feedstock cost. Published 2018. This article is a U.S. Government work and is in the public domain in the USA. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd. 相似文献
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This paper presents a framework to find optimal offshore grid expansions using a transportation model of the power grid. The method extends the standard mixed‐integer linear programming approach to the solution of the transmission expansion planning problem to account for fluctuations in wind power generation and load; this makes the method especially suited to identify optimal transnational offshore high‐voltage direct current grid structures for the integration of large amounts of offshore wind power. The applicability of the method is demonstrated by a case study of the North Sea region. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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Motivated by the increasing transition from fossil fuel–based centralized systems to renewable energy–based decentralized systems, we consider a bi‐objective investment planning problem of a grid‐connected decentralized hybrid renewable energy system. In this system, solar and wind are the main electricity generation resources. A national grid is assumed to be a carbon‐intense alternative to the renewables and is used as a backup source to ensure reliability. We consider both total cost and carbon emissions caused by electricity purchased from the grid. We first discuss a novel simulation‐optimization algorithm and then adapt multi‐objective metaheuristic algorithms. We integrate a simulation module to these algorithms to handle the stochastic nature of this bi‐objective problem. We perform extensive comparative analysis for the solution approaches and report their performances in terms of solution time and quality based on well‐known measures from the literature. 相似文献
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Annelie Carlson 《国际能源研究杂志》2002,26(12):1103-1115
The production of heat and electricity can cause large environmental impacts and, hence, large costs for society. Those are costs that are seldom taken into consideration. An important question is how the future technical energy systems should be formed if environmental costs were considered as any other good or service, such as raw material, capital and labour. This study comprises cost‐effective technical measures when monetary values of external effects are included in an energy system analysis. It is an analysis of how the present energy system can for society be cost‐effectively reconstructed to be more sustainable. A regional energy system model has been developed to perform the study and it concentrates upon production of heat in single‐family houses, multi‐dwelling buildings, non‐residential premises and district heating systems. The analysis adopts a business economic perspective, using present prices of energy carriers, and a more socio‐economic perspective, in which external costs are included. The result of the analysis is the optimal mix of energy carriers as well as new and existing heating plants that minimizes the costs of satisfying a demand for heat. The results show that it is profitable to invest in new heating plants fuelled with woody biomass. Furthermore, the external costs arising with satisfying the demand for heat can decrease substantially, 60%, by carrying through with the investments that are cost‐effective according to the institutional rules valid today. When monetary values of external costs are taken into consideration, this number is additional 5‐percentage points lower. It is shown that if environmental costs are included it is more expensive to continue with business as usual than it is to reconstruct and run a more sustainable energy system. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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Stig‐Inge Gustafsson 《国际能源研究杂志》2000,24(1):19-26
When timber is to be used in the form of furniture it must be dried. Green timber contains many times more water than wood and if it is placed indoors the water will slowly evaporate. When the fibre saturation point is reached the wooden parts start to shrink and the shape of the details will change. If the wood is dried before it is used for furniture parts this calamity is reduced because shrinking has occurred already in the drying kiln when the raw material was in the form of lumber. This drying process uses a lot of heat which is produced by electricity or by firing wood chips or oil in boilers. The cost for these energy sources varies during the season or, for electricity, also during the day. This paper describes how to optimize the use of energy in two drying kilns located at a small carpentry factory in the south of Sweden. Monitored values from the factory are used in order to describe the process in close detail. These values are then used as a basis for a mathematical model which is designed in the form of a mixed integer linear program. The method makes it possible to optimize the operating schemes for the two dryers. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
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This paper studies an integration model of production planning, scheduling, and order‐ based inventory distribution control systems. It models supply‐chain and production dynamics and employs process control to supply‐chain operations and the production process and scheduling. It embeds generalized disjunctive programming (GDP) and branch‐and‐reduce algorithms to obtain an optimal solution. Generalized disjunctive programming reformulates the original mixed integer nonlinear programming (MINLP) model and solves the new model with a lower number of integer variables. Afterwards, the branch and reduce algorithm, which is strengthened with outer approximation (OA) cutting planes, is able to find optimal solutions with permissible optimality gaps. The results show that supply network size does not affect forecast accuracy; there is a forecast error rate of 12.9%. Similar figures are also shown for the inventory level, which is expected to be 32% of demand level, production changeover time at 0.58 days, inventory ramp‐up period to meet the expected raw materials and final products inventory at 0.02 and 0.04 days respectively, and extra delivery time to meet a certain level of demand change at 1.1 days. The results show that the model is capable of controlling demand forecast, inventory level, and delivery quantity, so that the supply chain can avoid stock out at a minimal level of inventory, regardless of the size of supply‐chain networks. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd. 相似文献
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This paper presents an application of genetic algorithms (GA) for solving the long‐term power generation expansion planning (PGEP) problem, a highly constrained nonlinear discrete optimization problem. The problem is formulated into a mixed integer nonlinear programming (MINLP) program that determines the most economical investment plan for additional thermal power generating units over a planning horizon, subject to the requirements of power demands, power capacities, loss of load probability (LOLP) levels, locations, and environmental limitations. Computational results show that the GA‐based heuristic method can solve the PGEP problem effectively and more efficiently at a significant saving in runtime, when compared with a commercial optimization package. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
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In the last decade, technological innovations have resulted in considering distributed generation with heat recovery capability in addition to centralised generation. This work aims to develop a comprehensive model analysing techno-economic parameters of energy supply in an office building. The energy model is developed on the basis of the reference energy system with the linear programming technique. The objective function is the annual value of total costs of the energy supply system. The results of the model for the building of Sharif Energy Research Institute indicate that the most appropriate generation technology is an internal combustion engine of 461 kW and a water boiler of 152 kW. In addition to supplying the final service demand, hot water feeds an absorption chiller of 507 kW to produce cold water. Furthermore, storage systems of hot and cold water are required in order to achieve high load factors in the system. 相似文献
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英格兰北部城市Barnsley建有大量以生物质为燃料、中小规模的分布式供能系统,在可持续的分布式能源的发展上处于英国的领先地位。本研究对Barnsley两个典型的分布式供热系统的污染物排放进行了试验和数值模拟研究,分析其燃烧特性和整体性能。研究结果表明,以生物质为燃料的分布式供热系统,污染物的排放浓度在排放标准范围之内,而且所产生的污染物(如CO、CO2、NO和颗粒物)的浓度要低于燃煤锅炉。Barnsley成功开发和运行大量独立的"迷你"型分布式供热系统的经验,为我国农村和新型城镇建立和发展可再生新型供能模式提供了一个很好的参考和借鉴。 相似文献
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The purpose of this study is to demonstrate an analytical method that can be used to incorporate development in industrial sub‐sectors in national energy systems modelling analysis. The method is illustrated by a case study of the Swedish forest industry. The case study consists partly of a detailed industrial sub‐sector scenario analysis of the Swedish forest industry and partly of an analysis of the usefulness of incorporating such a detailed treatment of the industry in energy system modelling analyses. The sub‐sector analysis results in calculated energy and material flows for each scenario. The energy systems analysis results in a comparison of modelling results for the Nordic energy system, with and without the more detailed sub‐sector analysis of the Swedish forest industry. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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