Özdemir Küçük Esra, Kılıç Muhsin
Bursa Uludag University, Yenişehir İbrahim Orhan of Vocational School Department of Machine, 16900, Yenişehir, Bursa, Türkiye.
Bursa Uludag University, Engineering Faculty, Department of Mechanical Engineering, 16059, Görükle, Bursa, Türkiye.
Heliyon. 2023 Mar 29;9(4):e15007. doi: 10.1016/j.heliyon.2023.e15007. eCollection 2023 Apr.
Recovery of low-grade waste heat in industrial processes is an essential energy management topic. Yet, most low-temperature heat sources discharge their heat directly into the environment. The Organic Rankine Cycle (ORC), which has the benefits of being energy-efficient, enabling investment savings, and being ecologically friendly, is crucial in recycling energy from low-temperature waste heat. Both the application of the optimum cycle design and the provision of optimum working conditions are the issues that need to be focused on efficiently using energy. This study performs the energy, exergy, and exergoeconomic analysis of four different organic Rankine cycle configurations operating with renewable or low grade waste heat. The effect degrees and ratios of selected control factors are calculated using Taguchi and variance analysis methods to compare thermal and exergy efficiencies, total system cost, and unit cost of electricity produced by the system. The objective function of the multi-objective optimization problem is defined, and its solution is realized with the Taguchi-Grey Relational Analysis method. The best thermodynamic and exergoeconomic performance result is calculated for the configuration of ORC with Feed Fluid Heater-Internal Heat Exchanger (IHE-FFH-ORC). As a result of Taguchi and ANOVA analysis, the factors that most affect the thermal efficiency of the system, the exergy efficiency, the total system investment cost, and the unit cost of the electricity produced are, respectively, the evaporation temperature (∼50%), turbine efficiency (∼25%), working fluid (∼20%), subcooling (∼4%), pump efficiency (∼0.05%), and superheating (∼0.05%). As a result of the optimization process, the thermal and exergy efficiencies, the total system cost and the unit cost of produced electricity for the IHE-FFH-ORC power system are calculated as 22.6% and 73.5%, 1.06 $/h, 0.039 $/kWh and 2.9 years, respectively.
工业过程中低品位废热的回收是能源管理的一个重要课题。然而，大多数低温热源直接将热量排放到环境中。有机朗肯循环（ORC）具有节能、节省投资和生态友好等优点，对于从低温废热中回收能量至关重要。应用最佳循环设计和提供最佳工作条件都是有效利用能源需要关注的问题。本研究对四种不同的利用可再生或低品位废热运行的有机朗肯循环配置进行了能量、㶲和㶲经济分析。使用田口方法和方差分析方法计算选定控制因素的影响程度和比例，以比较热效率和㶲效率、系统总成本以及系统产生的电力单位成本。定义了多目标优化问题的目标函数，并通过田口-灰色关联分析方法实现其求解。计算得出带有进料流体加热器-内部换热器的有机朗肯循环（IHE-FFH-ORC）配置具有最佳的热力和㶲经济性能结果。根据田口方法和方差分析结果，对系统热效率、㶲效率、系统总投资成本和发电单位成本影响最大的因素分别是蒸发温度（约50%）、汽轮机效率（约25%）、工质（约20%）、过冷度（约4%）、泵效率（约0.05%）和过热（约0.05%）。优化过程的结果是，IHE-FFH-ORC电力系统的热效率和㶲效率、系统总成本以及发电单位成本分别计算为22.6%和73.5%、1.06美元/小时、0.039美元/千瓦时以及2.9年。
