Optimization of thermocline heat storage tank capacity for combined heat and power plant based on environmental benefits: Scenarios for China

• Published in: Journal of energy storage Vol. 57; p. 106303
• Main Authors: Wang, Zijie, Gu, Yujiong, Lu, Shuyin, Zhao, Ziliang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2023
• Subjects: Capacity; Combined heat and power; Environmental benefits; Heat storage tank; Optimization; Heat storage tank; Combined heat and power; Capacity; Optimization; Environmental benefits
• ISSN: 2352-152X; 2352-1538
• DOI: 10.1016/j.est.2022.106303

The operation of a combined heat and power (CHP) plant coupled with a heat storage tank (HST) can decouple heat–power constraints and improve the flexibility of unit operations during the heating season. A capacity optimization model is developed to solve the problem of HST capacity selection for deep peak shaving based on the heat–power decoupling principle of HST and peak shaving compensation policy in northeast China, taking a power plant as an example. The model takes the net present value of environmental benefits as the main optimization target function, and the particle swarm optimization (PSO) algorithm is used for optimization. The results show that the optimal HST capacity based on environmental benefits is smaller than the optimal HST capacity considering operating income. The heat load significantly impacts the configuration of the CHP system's optimal HST capacity, and the area corresponding to the optimal capacity is not the area where the maximum increment of deep peak shaving is located. The optimal HST capacity configured for the CHP plant is 170 MWh based on the characteristic daily load data of months. With the configured HST, the CHP plant can provide 8147.95 MW capacity for new energy grid-connected power generation every year during the heating season, eliminating 1692.33 tons of CO2, 41.68 tons of SO2, and 39.4 tons of NOx emissions. This study provides a HST capacity configuration method for CHP plant to improve the peak shaving ability and realize the sustainable development of society. •Peak shaving principle of heat storage tank (HST) for CHP units is analyzed in detail.•A HST capacity optimization model embedded operation optimization is proposed.•The capacity optimization model considers the peak shaving compensation policy.•The heat load significantly impacts than power load for the optimal HST capacity.