Abstract:

Renewable energy synthetic ammonia technology not only helps solve the problem of high energy consumption and high emissions in the traditional synthetic ammonia industry, but also provides a new way for the storage and consumption of renewable energy. In this work, an optimal design model of renewable energy synthetic ammonia system was established to address the seasonal demand of ammonia. The optimal configuration and operation scheme were determined, and the influences of seasonal ammonia demand on the design and operation characteristics of the system were analyzed. The results show that, compared with the case where ammonia is used as energy storage medium, the scale of the required synthetic ammonia production system powered by renewable energy increases significantly, and the cost of ammonia increases by 21% when ammonia is used as the raw material of nitrogen fertilizers. The loads of chemical production units and storage units present distinct performances of off-season and peak-season with the seasonal shift of the ammonia demands. Besides, in both of the above-mentioned two cases, the operation of the battery energy storage unit will be mainly determined by the downstream chemical production units, and the role of the energy storage battery unit is to smoothen the fluctuation of renewable energy so as to ensure the continuous and stable operation with low-load of chemical production units when the deficit of renewable energy is presented.

Key words: ammonia synthesis, renewable energy, optimal design, seasonal demands, energy storage

摘要：

可再生能源合成氨技术不但有利于解决传统合成氨工业高能耗高排放的问题，还为可再生能源的存储和消纳提供新途径。从氨的季节性需求特性出发，构建了可再生能源合成氨系统的优化设计模型，确定了系统的最优配置及其操作方案，阐明了氨的季节性需求对可再生能源合成氨系统设计和操作的影响特性。研究表明：与将氨作为储能介质的场景相比，在将氨作为氮肥原料，考虑其季节性需求时，所需可再生能源合成氨系统的规模显著增大，使得单位合成氨的成本增加约21%；化工生产单元和储罐的负荷也随着氨的季节性需求变化呈现出不同程度的淡季和旺季；在两种应用场景下，系统中电池储能单元的操作都主要由下游的化工生产单元决定，且储能电池单元的主要作用在于平抑可再生能源波动以保证化工生产单元在可再生能源不足时的持续稳定运行并维持其低负荷运行。

关键词: 合成氨, 可再生能源, 优化设计, 季节性需求, 储能系统