Optimal design of organic Rankine cycle system for multi-source waste heat recovery involving multi-period operation

This paper addresses a three-step method to design the optimal ORC waste heat recovery system (WHRS) that adapts to the multi-period and multi-source heat recovery requirements. In the proposed method, the candidate working fluids and the corresponding cycles of WHRS are preliminarily selected based on analysis of the heat source load curve and the quantitative relationship of temperatures between the heat sources and working fluids. In this step, the quantitative relationship for working fluid selection in single-source system is generalized to the multi-source WHRS, and a series of principles for the combination and classification of inflection points on heat source load curve are presented to simplify the design process and avoid the structure redundancy at the same time. Then, based on these selections, a multi-source and multi-cycle WHRS model is established and solved to determine the optimal configuration of multi-source WHRS, which consists of an ORC thermodynamic model and a waste heat recovery network (WHRN) model. The number of cycles, the working fluids, the WHRN structure, and the design and operating parameters are thus determined for multi-source and multi-cycle WHRS. At the last step, the time-sharing model is extended and solved to finalize the design of multi-source WHRS, so that the multi-period operation requirements can be easily met through the combination and sharing of operating units. The application and effectiveness of the proposed method are verified via an industrial case study and the results are expected to provide guidance for the design of the multi-period and multi source waste heat recovery process in practice. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This paper presents a three-step method for designing the optimal ORC waste heat recovery system that meets the requirements of multi-period and multi-source heat recovery. The method involves selecting candidate working fluids and WHRS cycles, establishing a multi-source and multi-cycle WHRS model, and finalizing the design using a time-sharing model.