Optimal Design of a Heat Recovery System Based on an Organic Rankine Cycle 2021-01-0206

This paper presents the implementation of an optimal design methodology to design a heat recovery system (HRS) based on an Organic Rankine Cycle (ORC). The optimal design sought to simultaneously minimize the total volume of the system and maximize the power recovered. As a result of the application of the methodology, a family of optimal solutions with different dimensions and capacities was obtained.

The implemented methodology was composed of three interacting modules. The first module corresponds to a parametric model that estimates the response of the system. The second module corresponds to a co-simulation scheme that exchanges data between the other two modules. The third module corresponds to an optimization strategy that explores the design space and finds the optimal solutions.

The optimal design methodology was implemented in a case study. The case study was an HRS used to recover energy from the exhaust gases of a small car. Given the case study conditions, the optimization model was set up to find small-volume solutions with the highest recover-power. As a result, a family of optimal solutions was obtained. That allows the designer to select the preferred solution from a range of sizes and performances that already consider the tradeoff between the variables. In addition, as the whole procedure is parametric, the designer can recalculate the solutions to consider a different case. As a result of the application of the methodology in the case study, a family with a volume range between 0.0139 m³ and 0.074 m³ was obtained. This family can recover between 331 W and 1835 W, depending on the final solution selection.