A Organic Rankine Cycle waste heat recovery cogeneration system for heat recovery and power generation to relieve grid pressure and save energy cost for a ferrochrome smelting plant is investigated. Through the recovery and utilization of previously wasted heat from the facility’s internal smelting process off-gases, the cogeneration system is introduced to generate electrical power to supply the on-site electricity demand and feed electricity back to the utility grid when it is necessary and beneficial to do so. In addition, the cogeneration system generates cooling power through a lithium bromide-water solution absorption refrigeration cycle to meet the cooling requirements of the plant. The heat recovery process for power generation is modeled and the optimal power dispatching between the on-site loads and the utility grid is formulated as an economic power dispatching (EPD) problem, which aims to maximize the plant’s economic benefits by means of minimizing the cost of purchasing electricity from the utility and maximizing revenue from selling the generated electricity to the grid. Application of the developed model to a ferrochrome smelting plant in South Africa is presented as a case study. It is found that, for the studied case, more than $1,290,000 annual savings can be obtained as a result of the proposed heat recovery power generation system and the associated EPD model. In addition to this, more than $920,000 annual savings is obtained as a result of the generated cooling power via the proposed absorption refrigeration system. The combined cogeneration system is able to generate up to 4.4 MW electrical power and 11.3 MW cooling power from the recovered thermal energy that was previously wasted.

研究了有机朗肯循环余热回收热电联产系统，用于热回收和发电，以减轻电网压力并节省铬铁冶炼厂的能源成本。通过从工厂内部冶炼过程中的废气中回收和利用以前浪费的热量，引入了热电联产系统来发电，以提供现场用电需求，并在必要和有益时将电力反馈给公用电网这样做。此外，热电联产系统通过溴化锂-水溶液吸收式制冷循环产生冷却功率，以满足工厂的冷却需求。对发电的热回收过程进行建模，并将现场负载与公用电网之间的最佳功率分配公式化为经济功率分配（EPD）问题，该问题旨在通过最小化成本来最大化工厂的经济效益从公用事业公司购买电力，并通过将所产生的电力出售给电网获得最大收益。作为案例研究，介绍了开发的模型在南非铬铁冶炼厂中的应用。发现，对于所研究的案例，由于所提出的热回收发电系统和相关的EPD模型，每年可节省超过1,290,000美元。除此之外，还有920美元以上，通过建议的吸收式制冷系统产生的冷却功率可每年节省000欧元。联合热电联产系统能够从先前浪费的回收热能中产生高达4.4兆瓦的电力和11.3兆瓦的冷却电力。