Report
Teaser, summary, work performed and final results
Periodic Reporting for period 1 - DryFiciency (Waste Heat Recovery in Industrial Drying Processes)
Teaser
The industrial sector accounts for 25% of the total final energy consumption in EU-28 in 2015, of which 12% to 25 % is attributable to industrial drying. Drying and dehydration processes are currently primarily fossil-fired, generating large volumes of low grade waste heat...
Summary
The industrial sector accounts for 25% of the total final energy consumption in EU-28 in 2015, of which 12% to 25 % is attributable to industrial drying. Drying and dehydration processes are currently primarily fossil-fired, generating large volumes of low grade waste heat that are not or only minimally utilized. Hence, industrial drying offers large potential for improved energy efficiency, reduction of fossil carbon emissions, and increased competitiveness by introducing advanced energy efficiency technologies.
The overall objective of the DryFiciency project is to lead the European energy intensive industry to high energy efficiency and a reduction of fossil carbon emissions by means of waste heat recovery and its valorization through means of high temperature heat pump technology. The project is mainly focusing on industrial drying and dehydration processes in the agricultural raw material industry, ceramic sector and pet care/feed industry. The results are also of relevance for other sectors such as e.g. pulp & paper or petro-chemical industries.
The consortium elaborates techno-economic solutions for upgrading idle waste heat streams into process heat supply at temperature levels up to 160 °C. The key elements are three advanced high temperature vapor compression heat pumps: two closed loop heat pumps for air drying processes, and an open loop heat pump for steam driven drying processes. The technology shall be widely replicable and adaptable to both newly built installations as well as for retrofitting. The DryFiciency solutions will be demonstrated under real production conditions in industrial drying processes of three leading European companies.
Work performed
The first tasks were to determine process parameters for the selected drying processes, which are kibble, brick and starch drying. Schematic integration schemes were developed and the boundary conditions and capacities for the integration of the three demonstrators, as well as for their full scale configuration, were defined. Key performance indicators (KPI) were elaborated to allow a comparable evaluation of the demonstrators. The KPIs comprise of sensible heat recovery of the system, coefficient of performance of the heat pump dryers, specific energy consumption, CO2 emissions avoided and production costs reduced. The performance and associated impact of the DryFiciency solutions will be assessed and validated during the demonstration phase of the project.
In parallel, the development of the heat pump systems started on component level. For the closed loop heat pumps, a novel refrigerant was produced, which is not subject to F-gas regulation and therefore suitable for high heat supply temperatures. All parts of the screw compressor were analyzed and adapted to high temperatures. Detailed studies were carried out to test the compatibility of the refrigerant and crucial parts of the screw compressor. Various novel lubricants were developed and analyzed regarding their chemical behavior when used with the refrigerant at higher temperatures. The heat pump cycles were modeled on component level. Four different closed heat pump cycle configurations were elaborated and the most suitable one in terms of efficiency and operability selected. It is a twin cycle water-to-water heat pump. Two closed loop demonstrators will be constructed, which use two different types of compressors: a screw and a piston compressor. Detailed planning documents were worked out for public tendering of the manufacturing of the two heat pumps.
For the open loop heat pump, an electric and oil-free turbo compressor was developed, which allows for temperature lifts of up to 50K in a two-stage vapor compression cycle. The unit is designed in a compact and cost-efficient way, where also the motor is included. Several turbo compressors were assembled and tested under air conditions. Detailed numerical simulations were carried out for the dimensioning of the prototype. The open loop heat pump was designed, dimensioned and constructed with a special focus on the real operating conditions at the demonstration plant. Finally, the open loop system was installed at a test rig, and tested successfully with steam turbo compressors up to 130°C.
At all three demo-sites, the space and infrastructure were evaluated for the heat pump integration Operational schedules were planned and aligned to the respective drying processes. In addition, first components required for the integration of the heat pumps such as e.g. heat exchangers were designed, dimensioned and ordered.
To facilitate wide-spread post-project uptake, various communication tools were developed and implemented for different target groups. Stakeholder relations to end-users, multipliers, the R&D community and the general public were successfully started, including the establishment of an External Experts Advisory Board. The project was presented at seven relevant scientific / industrial conferences, two workshops, and at three trade fairs.
Final results
The three demonstrators will be the first high temperature heat pumps implemented in real industrial environments (TRL7) aiming to reach supply temperature of up to 160°C. The two closed loop heat pump systems use a novel non-flammable, non-toxic refrigerant with a minimum global warming potential. Adapted screw and piston compressors and a fine-tuned refrigeration oil are applied. The ambition of the open loop system lies in the development of a cost-efficient multi-stage compression system for steam. It is based on an oil-free, fully integrated turbo compressor allowing supply temperatures of up to 155°C.
The core results expected at the end of the project include three fully functional industrial heat pump systems integrated in industrial environments and validated on component and system level to achieve the following:
• Energy savings of sensible heat of 40 to 80%.
• Primary energy savings ranging from approx. 3.200 to 13.000 MWh/a.
• CO2 reductions ranging from approx. 800 t-CO2/a to 2800 t-CO2/a.
• Improved energy efficiency from 55 to 80%.
• Cost reduction from 4% to 20% / kg product.
In addition, business models, appropriate IP protection and exploitation/investment plans are developed to ensure post project roll out of the heat pumps.
The DryFiciency project has the potential to address and cover the full range of industrial drying processes and can therefore act as key enabler for market uptake of the novel high temperature heat pump technologies for most energy intensive industries within the EU. In line with the EU 2030 climate and energy targets and the Energy Efficiency Directive (2012/27/EU) DryFiciency will reduce CO2 emission significantly and increase the energy efficiency in energy intensive industrial processes. Furthermore, DryFiciency will support the industry in complying with the new F-Gas Regulation limiting the total amount of fluorinated gases sold.
Website & more info
More info: http://www.dryficiency.eu.