利用风光电解水制氢合成氨是“双碳”背景下化工业低碳转型的重要路线。然而，由于风光的固有波动性与氢、氨负荷的需求特性不匹配，导致系统用电成本大幅上升。传统的解决方案，如大规模化学储能或完全依赖外部电力市场来平衡功率，往往缺乏经济效益。因此，本文考虑利用规模化储气系统、负荷灵活运行方式以及多市场交易等灵活性资源，开展风光电解水制氢合成氨系统建模和优化运行研究，解决系统的技术经济问题。本文的主要内容如下：首先，从利用氢负荷有限灵活性，电、氢市场等灵活性资源的角度出发，提出了考虑氢负荷连续调节灵活性的风光电解水制氢合成氨系统运行优化方法。面向风光电解水制氢合成氨系统，提出考虑氢负荷连续调节灵活性的小时级运行模型。基于电、氢、氨市场交易方式，建立系统的多市场交易模型。采用统一的时间分层离散方法，构建系统多时间尺度、多市场交互框架。考虑风光出力的不确定性，建立两阶段鲁棒优化模型，决策风光电解水制氢合成氨系统多时间尺度、多市场交易策略，降低系统运营成本。其次，从利用氢负荷临时的额外灵活性、储氢系统等灵活性资源的角度出发，提出了考虑氢负荷启停灵活性的风光电解水制氢合成氨系统运行优化方法。建立氢负荷常规、备用、超调全工况状态集合，刻画工段非连续多稳态调节区间。借鉴动态规划思想，显式表征系统小时级可调度域。提出基于多时段可调度域的储氢系统的自适应运行优化方法，以实现合成氨反应器在不同运行模式间的策略性切换，提升系统能源利用效率。最后，从利用外部氨市场、储氨系统等灵活性资源的角度出发，提出考虑氨市场长协与零售交易的风光电解水制氢合成氨系统运行优化方法。基于风光机组中长期发电量预测结果，显式表征系统周时间尺度多时段可调度域。挖掘氨零售市场交易灵活性，提出考虑氨市场长协与零售交易的储氨系统自适应周期检查库存策略，支撑储氨水平中长期调度与氨零售市场交易决策，避免有限储氨容量条件下的库存溢出及交割违约问题，增加系统氨交易收益。综上所述，本文为风光电解水制氢合成氨系统提出了一系列运行优化策略，以解决系统的技术经济问题。这些策略不仅能改善风光电解水制氢合成氨技术路线的发展前景，更有助于推动化工行业加速低碳转型。
Renewable power to ammonia is a crucial pathway for the chemical industry's low-carbon transformation under the "dual carbon" initiative. However, the mismatch between the inherent variability of renewables and the demand characteristics for hydrogen and ammonia significantly increase electricity costs. Traditional solutions, like large-scale chemical energy storage or complete reliance on the external electricity market for power balancing, often lack economic efficiency. Therefore, this paper considers using large-scale gas storage systems, load flexibility, and multi-market trading to optimize the operation of the renewable power to ammonia system, addressing its technical and economic challenges. The main content of this paper is as follows:Firstly, by utilizing the limited flexibility of hydrogen load and the flexibility of electricity and hydrogen markets, an optimization method is proposed that accounts for the continuous adjustability of hydrogen load in the renewable power to ammonia system. An hourly operation model based on multi-market trading is established, using a unified time-tiered discretization method to create a multi-time scale, multi-market interaction framework. Considering the uncertainty of renewable output, a two-stage robust optimization model is developed to decide on multi-time scale, multi-market trading strategies, thus reducing operational costs. Secondly, by exploiting the temporary additional flexibility of the hydrogen load and the flexibility of hydrogen storage system, an optimization method that includes the start-stop flexibility of the hydrogen load is introduced. This method establishes a full-condition state set for normal, standby, and overloading modes, depicting the non-continuous multi-stable adjustment range of the system. Employing dynamic programming concepts, the system's hourly dispatchable region is characterized, leading to an adaptive operation optimization method for the hydrogen storage system that enhances system energy utilization efficiency through ammonia synthesis reactor’s strategic mode switching.Lastly, by leveraging external ammonia markets and storage systems, an optimization method is proposed that considers long-term ammonia contracts and retail ammonia transactions. Based on long-term electricity generation forecasts of renewable generators, the system's weekly time-scale multi-period dispatchable region is characterized, facilitating an adaptive inventory checking strategy that supports long-term ammonia storage scheduling and retail market trading decisions, thus avoiding inventory overflow and delivery defaults under limited storage capacity and increasing ammonia trading profits.In summary, this paper proposes a series of operation optimization strategies for the renewable power to ammonia system to address its techno-economic issues. These strategies not only improve the development prospects of the renewable power to ammonia technology route but also facilitate the low-carbon transformation of the chemical industry.
