Performance Analysis and Parametric Analysis of the Organic Rankine Cycle Considering Seasonal Temperature Variations

Under the “dual carbon” strategy, the organic Rankine cycle (ORC) represents a key technology for efficiently recovering low-grade industrial waste heat in inland factories. This study addresses ORC operational instability caused by seasonal temperature fluctuations and high cooling-water costs in inland regions. An ORC system powered by industrial waste heat is investigated. A steady-state simulation model is developed in Aspen Plus to analyze the effects of expansion pressure, condensation pressure, cooling-water flow rate, and working-fluid flow rate on system performance, and to filtrate parameters to maximize economic returns. The results demonstrate that optimal expansion pressure yields maximum net shaft power. Condensation pressure and the cooling-water flow rate are closely linked, necessitating a balance between power generation revenue and cooling costs. An optimal range for working-fluid flow rate is also identified. Seasonal temperature variations significantly influence system performance. Higher summer temperatures increase condensation pressure and reduce revenue, while lower winter temperatures enhance revenue when filtrated parameters are used. This research provides theoretical and technical references for achieving efficient, cost-effective, year-round ORC operation in inland factories. In the case study, the analysis for seasonal temperature variations increases the total annual revenue by CNY 2.217 million, with an annual average system efficiency of 10.59%.