Heat-Exchanger Network Synthesis Involving Organic Rankine Cycle for Waste Heat Recovery

Abstract

This article aims to present a mathematical model for the synthesis of a heat-exchanger network (HEN) which can be integrated with an organic Rankine cycle (ORC) for the recovery of low-grade waste heat from the heat surplus zone of the background process. An ORC-incorporated stagewise superstructure considering all possible heat-exchange matches between process hot/cold streams and the ORC is first presented. On the basis of this superstructure, the model for synthesizing ORCintegrated HENs is formulated as a mixed-integer nonlinear program (MINLP). A two-step solution procedure is proposed to solve the MINLP model. First, a stand-alone HEN is synthesized to minimize the external utility consumption. An ORC is then incorporated into the HEN with the objective of maximizing the work produced from waste heat (in the heat surplus zone below the process pinch) without increasing the use of a hot utility. A literature example is solved to demonstrate the application of the proposed model for industrial waste heat recovery.

Systematic Methods for Working Fluid Selection and the Design, Integration and Control of Organic Rankine Cycles—A Review

“…Chen et al [120] present a mathematical model for the synthesis of a heat-exchanger network (HEN) which is integrated with an organic ORC for the recovery of low-grade industrial waste heat. An ORC-incorporated stage wise superstructure considering all possible heat-exchange matches between process hot/cold streams and the ORC is first presented.…”

Synthesis of transcritical ORC-integrated heat exchanger networks for waste heat recovery

“…Figure 2 illustrates the superstructure for the synthesis of transcritical ORC-integrated HENs for recovery of low-grade waste heat from the background process. This superstructure, an expansion of the stage-wise HEN superstructure of Yee and Grossmann (1990) and Chen et al (2014), incorporates an ORC and assumes nonisothermal stream mixing. In the superstructure, HE ijk is the process-to-process heat exchanger; H hj and C ic are the heater and cooler for providing extra hot or cold utilities at the end of process streams; rh ijk and rc ijk are the split ratios for the hot and cold process streams at stage k; t ik and t jk denote the intermediate temperatures; PV m and TC m denote the pump and the turbine for working fluid m in the ORC; evaporators E imk and condensers C mjk are used for exchanging the waste heat between the process streams and the working fluid m; t e mk and t c mk are intermediate temperatures around the evaporators or the condensers.…”

“…The example from the work of Desai andBandyopadhyay (2009) andChen et al (2014) involves three hot and four cold streams with steam and cooling water as the heating and cooling utilities. Given data for the problem, including the inlet and outlet temperatures, heat capacity flow rates, the available utilities of hot and cold process streams are showed in Table 1.…”

Dynamic model of supercritical Organic Rankine Cycle waste heat recovery system for internal combustion engine

“…Around 86% of this energy demand is fulfilled from fossil fuels (International Energy Statistics, 2016). Over the last few decades, the prices of fossil fuels have also increased by around three times (Chen et al, 2014) and, as a result, energy generated from fossil fuel has become expensive. Moreover, the greenhouse gases and pollutant emissions due to the burning of fossil fuels have an unavoidable effect on the environment and Ozone-layer depletion.…”