蒙特卡罗法在分布式供能系统不确定性评价中的应用

Application of Monte Carlo Method in Uncertainty Evaluation for Cogeneration Systems

分布式供能系统的设计和运行易受诸多不确定性因素的影响。文中以分布式供能系统优化运行程序和评价指标模型为基础,运用蒙特卡罗模拟方法对分布式供能项目进行不确定性评价。对某分布式供能系统进行了仿真研究,计算了系统各评价指标的概率分布及关键影响因素。案例计算结果表明:一次能源利用率预测的风险度较低,年能耗费用、年CO2减排率和年NOx减排率预测的风险度均较高;系统年能耗费用和一次能源利用率的最大影响因素为电负荷,年CO2减排率和年NOx减排率的最大影响因素为天然气价;多余电力上网政策对系统的4种评价指标均会产生一定的影响。计算结果同时验证了蒙特卡罗模拟方法在分布式供能系统不确定性评价中的有效性。

The design and operation of cogeneration systems is vulnerable to many uncertain factors. In this paper, based on the optimal operation code and evaluation model, uncertainties of cogeneration projects were evaluated using Monte Carlo simulation method. Through simulating to a certain cogeneration system, the probability distributions and key-influencing factors of evaluation indices were calculated. The results show that there is small uncertainty in the predicted primary energy rate whereas annual energy cost, annual CO2 reduction rate and annual NOx reduction rate are greatly affected by input uncertainties. Factor with the largest impact on uncertainties of annual energy cost and primary energy rate prove to be electrical load. For annual CO2 reduction rate and annual NOx reduction rate, the key-influencing factor is natural gas price. The policy that surplus electricity is exported to the power grid has a certain impact on the four evaluation indices. The computational results also prove that the Monte Carlo method in uncertainty evaluation for cogeneration systems is valid.