SCIENTIFIC PUBLICATIONS

1. Conference paper: Veronika Wilk, Michael Lauermann, Franz Helminger, 2019, Decarbonization of industrial processes with heat pumps, Proceedings of the 25th IIR International Congress of Refrigeration: Montreal, Canada, August 24th-30th, 2019.

Abstract:

To counteract climate change the efficient use of energy in industry becomes increasingly important. Heat pumps enable decarbonized industrial processes by replacing fossil fuels with electricity. DryFiciency develops and demonstrates high temperature heat pumps using OpteonMZ as refrigerant to supply hot water up to 160°C. Heat pumps will be installed in drying processes for starch and bricks in two Austrian companies in spring 2019. We present design considerations for high temperature heat pumps, as well as the expected CO2 reductions and primary energy savings. Calculations are based on numerical process simulation. At the two demo-sites CO2 emission reductions up to 40-90% and primary energy reduction from 20-80% can be achieved compared to natural gas. Similar considerations are presented for larger roll-out in EU. Heat pumps improve the energy efficiency of industrial processes significantly. The demonstrators are an important step in the development of viable industrial solutions.

To be purchased soon under: http://www.iifiir.org/  

 

2. Conference paper: Michael Bantle, Christian Schlemminger, Cecilia Gabielii, Marcel Ahrens, Kjetil Evenmo, 2019, Turbo-compressor for R-718: Simulation and verification of a two-stage steam compression cycle, Proceedings of the 25th IIR International Congress of Refrigeration: Montreal, Canada, August 24th-30th, 2019.

Abstract:

Water (R-718) is a safe and energy-efficient refrigerant. Mechanical vapour recompression (MVR), an open-loop heat pump using R718, can significantly reduce the energy consumption for steam-heated processes like drying, pasteurization, evaporation or distillation. However, the existing compression technology is not cost-efficient, especially in the capacity range from 500 kW to 4 MW. Therefore, a novel two-stage turbo-compressor system, developed for application in industrial superheated steam drying and based on mass-produced automotive turbocharger technology, was developed. Its performance was evaluated in a test facility, showing that it is possible to compress superheated steam from atmospheric pressure up to 3 bar, delivering 300 kW at 133°C, with a COP of 5.9, an isentropic efficiency of 74% and a Carnot efficiency of 48%. With an estimated investment cost of 150 €/kW installed heating capacity, the system clearly has the potential of being a cost-effective solution for heat recovery in steam-heated industrial processes.

To be purchased soon under: http://www.iifiir.org/

 

3. Conference paper: Michael Bantle, Christian Schlemminger, Ignat Tolstorebrov, Marcel Ahrens, Kjetil Evenmo, 2018, Performance evaluation of two stage mechanical vapour recompression with turbo-compressors, Proceedings of the 13th IIR Gustav Lorentzen Conference, Valencia, 2018.

Abstract:

Mechanical Vapour Recompression (MVR) is an open loop heat pump system using water (R718) as working fluid, one of the most abundant and safest refrigerant on the planet. The concept can significantly reduce the energy consumption for steam based processes like drying, pasteurization, evaporation or distillation but also for steam production itself. However, the compression technology is commonly not cost efficient especially for small scale productions in the capacity range from 500 kW to 4 MW.  A two stage turbo-compression system was developed and tested based on mass produced automotive turbocharger technology. The turbo-compressor of the first stage reached a pressure ratio of 1.68 and is designed for a mass flow of 400-600 kg/h superheated steam. The second stage turbo-compressor had an identical design and achieved a pressure ration of 1.72. Between compression stage one and two de-superheating is applied by water injection. With the developed system it is possible to compress superheated steam from atmospheric pressure to above 2.9 bar, where it can be condensed at a temperature of 132°C. The COP of the performed investigation was 7.8, when the achievable condensation energy is compared to the total amount of energy supplied to the system. Without the losses in the inverters, motor and gearbox the COP is 9.4, which is the COP when only the isentropic losses of compression are considered. This means that the isentropic efficiency is around 70% of the Carnot efficiency and the system efficiency is still 58% of the Carnot efficiency, even when all loss are considered.

The conference proceedings are available for purchase http://www.proceedings.com/40853.html 

 

4. Master thesis: Ahrens Ulrich Marcel, 2018, Experimental and numerical analysis of a two-stage turbo compressor system for industrial superheated steam drying, Technical University of Braunschweig.

The aim of this master's thesis was the experimental analysis of the turbo compresso rtechnology performance as well as the development of a numerical turbo compressor model and the evaluation of the two-stage turbo compressor performance. To analyse the performance of the turbo compressors technology, experiments were performed at the test facility developed by SINTEF Energy Research. A suitable numerical turbo compressor model was identified and validated for the development of a system model. The achieved results and experiences were used for the evaluation of the two-stage turbo compressor performance.

The experiments demonstrated a stable operation of the two-stage turbo compressor system. The compressor maps have been created which allow an analysis of the performance and operating range of the turbo compressor. The numerical models were able to reproduce the results in a good approximation and allowed the estimation of further operating points. During this elaboration, the system was able to compress superheated steam from atmospheric pressure to above 3.0 bar, where it can be condensed at a saturation temperature of 133.5 °C. The COP of the performed investigation was 5.9, when the achievable condensation energy is compared to the total amount of energy supplied to the system.

Find the publication on Zenodo - click here

 

5. Conference paper: Veronika Wilk, Michael Lauermann, Franz Helminger, 2018, Design zweier Wärmepumpen-Demoanlagen für die industrielle Trocknung (Design of two heat pump demonstration systems for industrial drying), Proceedings of DKV Tagung 2018, 21-23.11.2018, Aachen, Germany.

The paper focuses on the design of two high temperature heat pump systems to be demonstrated first-time in industrial drying applications. The drying processes of the demo sites at Agrana Stärke GmbH and Wienerberger AG are explained with and without heat pump integration, the design questions to be considered are elaborated on, and the two compressors to be demonstrated first-time - a semi-hermetic scroll compressor from Bitzer and a piston compressor from Viking Heat Engines A/S - are presented. In addition, possible refrigerant circuit configurations including their pros and cons are elaborated. Finally, an outlook on the next steps to be taken within the project is provided.

This paper is available in German only. The conference proceedings are available for purchase http://www.proceedings.com/1430.html

 

6. Conference paper: Michael Bantle, Christian Schlemminger, Marcel Ahrens, Kjetil Evenmo, 2018, Kennfeld und Leistungsanalyse einer zweistufigen Turbokompressor- Brüdenverdichtung (Characteristic map and performance analysis of a two-stage turbo compressor vapour recompression), Proceedings of DKV Tagung 2018, 21-23.11.2018, Aachen, Germany.

The paper focuses on the potential of a two-stage turbo compressor vapour recompression for industrial applications and elaborates on the performance data achieved with a novel turbo-compressor developed by Rotrex A/S within the DryFiciency project. The set-up of the lab environment of the mechanical vapour recompression (MVR) system is presented. The characteristic map and performance data of the turbo compressors tested in 2-stages is explained in detail.

This paper is available in German only. The conference proceedings are available for purchase http://www.proceedings.com/1430.html

 

NON-SCIENTIFIC PUBLICATIONS

1. Online brochure: LARGE SCALE HEAT PUMPS IN EUROPE, EHPA's Industrial and Commercial Heat Pump Working Group, 2018.

This brochure gives insight about 16 large heat pump applications including one demo site from DryFiciency project, Agrana drying unit. 

Click here to view and download 

 

2. Online brochure: SPIRE projects - Power to your know-how, A.SPIRE, 2016. 

Click here to view and download 

 

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