Report

Teaser, summary, work performed and final results

Periodic Reporting for period 2 - I-ThERM (Industrial Thermal Energy Recovery Conversion and Management)

Teaser

In the European Union, industrial processes are currently responsible for one third of primary energy consumption. Most of these processes, however, involve a rejection of large quantities of heat to the environment whose recovery as heat or conversion to another form of...

Summary

In the European Union, industrial processes are currently responsible for one third of primary energy consumption. Most of these processes, however, involve a rejection of large quantities of heat to the environment whose recovery as heat or conversion to another form of energy, such as electricity, can reduce energy demand, lead to fuel cost savings and contribute to meeting emission reduction and decarbonisation targets.

In recent years, the potential for heat recovery has been increasingly recognised and the heat recovery business is expected to expand significantly. However, for this to materialise and for the European manufacturing and user industries to benefit from these developments, technological improvements and innovations should take place aimed at improving the energy efficiency of heat recovery equipment and reducing installed costs.

In this context, the aims of the I-ThERM project are to investigate, design, build and demonstrate innovative plug and play waste heat recovery solutions and the optimum utilisation of energy within and outside the plant perimeter for selected applications with high replicability and energy recovery potential in a wide temperature range (70 °C to 1000 °C).

Work performed

In the first two years of I-ThERM, the coordination and management of the project ensured that all activities fulfilled the requirements of scope, timeliness and quality. Synergy between the partners was achieved by regular communication and information exchange while dissemination activities were carried out through 3 international workshops, and attending international events including the SPIRE ones in Brussels.

The heat recovery potential in the European Union was assessed through a literature review which identified and quantified primary energy consumption in the major industrial sectors, considered waste heat streams and their temperature levels, and potential energy recovery technologies.

The EINSTEIN energy auditing tool-kit has been enhanced and now includes the I-ThERM technologies. Routines to automatically analyse historical monitoring data, calibrate the models, forecast energy consumption and optimise systems performance were implemented. These capabilities will be coupled with the innovative monitoring and control platform also being developed within the I-ThERM project and they will be tested and evaluated with data from the demonstration sites.

The I-ThERM project considers the design, manufacture and demonstration of direct exhaust heat recovery systems using innovative heat exchangers.

The first technology is the Heat Pipe Condensing Economiser (HPCE) for which the objective is to cool the exhaust gases below their dew point to increase the amount of heat that can be recovered. For these reason, innovative coatings for corrosion protection against environments characterised by the presence of sulfuric acid are being developed. The HPCE design was carried out based on data gathered through an experimental characterization of the heat source at the demonstration site at the Arluy S.L.U. biscuit factory (Spain).

The flat heat pipe system (FHPS), instead, is a heat exchanger technology which aims at recovering heat from high temperature radiating surfaces. The FHPS will be demonstrated at the wire rod mill facility at Arcelor Mittal Gijón (Spain). A prototype module of the FHPS has been designed, manufactured and tested in the laboratory before being installed and tested at the actual demonstration site. The experimental dataset allowed the calibration of the design tools and propose an improved design of the modular FHPS with greater number of modules and a high emissivity coating.

The I-ThERM project also considers the conversion of waste heat to electricity using two new bottoming thermodynamic cycles: the Trilateral Flash Cycle (TFC) for low grade applications (70 to 200°C) and the a Brayton cycle operating with Carbon Dioxide in the supercritical state (sCO2) for medium to high temperatures ones.

A full-scale 120 kW TFC unit has been designed and built for a proof of concept testing phase in which operating parameters will be tuned and control strategies be developed. The experimental campaign will be further supported by transient modelling of the TFC system, including a two-phase positive displacement expander. The developed TFC system now has a high technology readiness level. It is characterised by a packaged design and power electronics provision for connection to the European electricity grid. The TFC system once tested and optimised will be installed and demonstrated at the TATA Steel site at Port Talbot (UK).

The demonstration site for the sCO2 system will be an industrial scale test rig at Brunel University London that has been purposely designed for the I-ThERM project. The experimental facility will comprise a 750 kW heater, generating 750oC exhaust gas, and a packaged system incorporating the Compressor-Generator-Turbine (CGT) unit that has been developed through aerodynamic, vibration and structural analysis using appropriate simulation and design tools. The CGT system will also include some ancillary equipment for lubrication and drainage as well as power electronics to export the

Final results

The ambition of the I-ThERM project is to develop and demonstrate heat recovery technologies that will overcome many of the disadvantages of conventional technologies and create a pathway for much wider adoption of heat recovery by industry. In the first two years of the project significant progress has been made beyond the state of the art, namely:
- The EINSTEIN tool-kit has been enhanced to include the I-ThERM technologies as well as on-line monitoring and optimization capabilities.
- A packaged, plug and play low grade heat to power conversion system based on the Trilateral Flash Cycle has been designed and built for pilot testing and design optimisation.
- A single ~50 kW shaft Compressor, Generator and Turbine (CGT) unit for high temperature heat to power conversion working with supercritical carbon dioxide has been designed. Manufacture and assembly of the unit is in progress.
- A heat pipe condensing economizer has been designed to harvest sensible and latent heat from baking oven exhausts the food sector.
- The design of the flat heat pipe system was optimized thanks to test campaigns on a prototype in laboratory and the actual demonstration site.
- Coatings for corrosion protection against environments characterised by presence of sulfuric acid have been developed and are currently being evaluated.
- Substantial know-how is being developed on heat recovery and waste heat to power conversion systems. The creation of this knowledge and dissemination to the scientific and industrial communities as well as policymakers, will lead to greater awareness of the potential of these technologies and facilitate their adoption by industry. Apart from employment opportunities, this will lead to a reduction in energy consumption and greenhouse gas emissions and will contribute to meeting the EU’s emission reduction targets.

Website & more info

More info: http://www.itherm-project.eu/.