Energy, exergy, economic and exergoeconomic (4E) multicriteria analysis of an industrial waste heat valorization system through district heating

Abstract

The purpose of this article is to determine the multicriteria-optimal design of an industrial waste heat recovery system for district heating in Grenoble (France). Energy, exergy and cost flow balances were applied unit by unit allowing to assess the process performance based on two innovative methods. First, the performance assessment includes all units involved in the heat valorization process, not only focusing on the recovery system. Second, the yearly management of energy flows was optimized through mixed-integer linear programming, anticipating fluctuations in residential demands and waste heat availability. This multicriteria analysis with a systemic-anticipative approach allowed to select the appropriate inlet temperature and storage capacity. It was found that the most promising inlet temperature and heat storage capacity are 35 °C and 30 MWh, respectively.With this design, the system recovers 41% of industrial waste heat, covers 48% of residential needs, has an estimated net present value of 11.7 million euros over 20 years, and reduces the district's overall exergy destruction and exergy destruction costs by 20% (4.2 GWh/year) and 9% (286 k€/year), respectively. Remarkably, none of the mono-criterion analyses prioritized this design.Therefore, the multicriteria analysis with systemic-anticipative approach was of utmost importance for detecting the most promising solution.

Flexible waste heat management and recovery for an electro-intensive industrial process through energy/exergy criteria

“…The LNCMI being a public research large instrument, its data and operation can be used as a representative use case for the waste heat recovery of electro-intensive industrial processes. Various studies have been carried out for the LNCMI waste heat recovery project: ▪ Planning laboratory experiments under environmental, economic or social constraints [5] ▪ Studying the flexibility of the LNCMI consumption profiles based on the identification of typical experiments [6] ▪ Multi-actor optimisation applied to the LNCMI waste heat recovery project [7] ▪ Studying the influence of the thermo-hydraulics of the LNCMI electromagnet cooling system on the LNCMI economic and environmental balance [8] ▪ Optimisation based on energy and exergy criteria [9,10] ▪ Developing open science on the LNCMI use case [11] These studies enabled to address various typical issues for waste heat recovery, applied to the LNCMI use case. Regarding the flexibility of the LNCMI experimental planning, and therefore of waste heat production, lessons learned point to the great difficulty in categorising the LNCMI experiments.…”

OMEGAlpes, an Open-Source Optimisation Model Generation Tool to Support Energy Stakeholders at District Scale

“…Energy analysis alone can be insufficient to assess the quality of energy streams in a system or to offer optimal ways to transform energy [80]. The exergy module serves the primary purpose of determining exergy destruction within a unit.…”

“…Moreover, the economic notions that can be considered, based on the cost of energy, can be applied in the same way to exergy, thus giving an exergo-economic evaluation. This makes it possible to provide a wider range of technical assessments with energy, economic, exergy, and exergo-economic concepts [80].…”

A Novel Concept for Sustainable Food Production Utilizing Low Temperature Industrial Surplus Heat

“…Space heating and district heating represent the highest potential for direct utilization of industrial surplus heat [34]. This includes, for example, surplus heat from research facilities [35]. However, the profitability of district heating systems depends on population density [12], and Nordic countries tend to have low population densities away from the main cities.…”