Parameters of drying processes were determined, schematic integration schemes were developed, and boundary conditions/capacities for integration were defined. 5 KPIs allowing the demonstrators’ evaluation were elaborated. In parallel, key components were developed. For the closed loop, a novel lubrication oil, working well with refrigerant selected at temperature up to 160°C, was developed. More than 20 samples had to be analysed. A screw compressor was adapted for HT application. 40 parts were replaced, omitted, or left in place. A piston compressor was tested with different lubrication oils. 8 piston and 4 screw compressors were built/tested. For the open loop, an electric, oil-free steam turbo compressor designed to allow temperature lifts of up to 50K in a two-stage vapor compression cycle was developed. 2 prototypes were built, tested, and integrated in the open loop HP. Designs of main components of HP cycles were simulated for most efficient/reliable operations. For the closed loop, 4 cycle configurations were analyzed in-depth. Two HP prototypes were built. In case of the open loop, the HP system was designed, constructed, and installed at a test rig to be tested extensively using different turbo compressor models. Simulated compressor maps were produced successfully before sending the system for installation. Final demonstrator layouts were worked out in accordance with quality/safety standards. Space and infrastructural requirements were evaluated. Operational schedules and control strategies were elaborated and implemented. Components, services, and infrastructural facilities for HP integration were sourced and installed. For the open loop, adapted batch dryers were designed, built, and integrated. Start-up and trial operations were conducted according predefined operating conditions to test HP functionalities. Closed loop HPs passed commissioning. For the open loop, only dryers were fully commissioned. 2 HTHPs were fully operated first-time in industrial setting at TRL7 and analysed in terms of performance/improvement potential. Data acquisition systems were set-up including reporting with interactive data visualization. Maintenance/adjustment work was conducted. Measures to improve on efficiency were worked implemented. Measured data was validated in terms of KPIs defined at project start.
Core results include three advanced HTHP solutions for upgrading idle waste heat streams to process streams of up to 160°C (closed) resp. 155°C (open loop) in industrial drying processes. Each of the closed loop demonstrators used for air drying was operated for more than 4,000 hours. Both showed end-energy and carbon emission savings of up to 80%. Open loop dryer has shown improved efficiency and capacity of more than 75%. Additional operational hours will be used to further optimize and validate the systems.
Follow-up research and innovation projects geared at decreasing ROI, further improving performance, and implementing HTHPs in other applications and sectors including a.o. food, chemical or wood processing have started already respectively will be further pursued including DryFiciency partners but also new ones. In order to increase competence on industrial HP technologies and overcome obstacles for broad application 4 DryF online seminars, a DryF final conference, and DryF online training program (+100 trainees) were developed and implemented. Event recordings, presentations, and videos on three demonstrators were made accessible on YouTube and the projects’ website. Besides, the project and selected results were presented at more than 25 conferences/WS and in 10 conference publications with more results to be published post-project.
