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Integrated solutions for low-temperature waste heat recovery and exploitation in industrial processes

Acronym: Industrial heat pumps

Duration: 2017-2021

Target sectors: Industry & Marine

Project description

The project deals with the development of integrated solutions for waste heat exploitation, through upgrading the waste heat with a high-temperature heat pump, and then re-using it. In order to improve flexibility, minimize the rejected heat, and gain an overall control of energy flows, the heat can be also used for power production with the same unit (bi-directional process), and thus conclude to a reversible heat pump/organic Rankine cycle. Focus is given on low-temperature heat (below 100-120oC), which represents a large fraction of the total one, since its utilization currently leads to unattractive solutions with long payback period.

The project addresses two pillars presented next:

  1. Pillar I: Waste heat upgrade and re-use with a new vapour compression heat pump, using environmental-friendly working fluids with low GWP.
  2. Pillar II: Waste heat conversion to power, using the same heat pump but with a reversible operation (using the same compressor/expander), leading to an Organic Rankine Cycle (ORC) unit.

Specific objectives

The specific objectives of the project are listed next:

  • Mapping of the heat potential in the industrial and marine sectors.
  • Research on working fluids, according to the temperature level, application, expected performance, and following all current and future environmental restrictions on fluids.
  • Development of a novel heat pump configuration for waste heat upgrade.
  • Design optimization of the reversible heat pump/ORC for efficient operation at both modes, focusing on a high isentropic efficiency of the compressor/expander.
  • Implementation of cost-benefit analysis, in order to identify the benefits of the end-users (in the targeted sectors: industry and ships) and the resulting payback period.

News & results

  • September 2017: Kick-off meeting at NCSR Demokritos.
  • April 2018: The potential of high-temperature heat pumps in EU industry and the marine sector has been concluded. The main results for the industrial sector have been submitted for publication.
  • September 2018: Preparation for the ORC2019 Conference that will take place in Athens, in September 2019. Some parts of the project results will be presented in this international event.
  • August 2021: The project has been successfully finalized with all work conducted within the planned time schedule.

Further research & activities

Further research-related activities of our group to be pursuit in future projects concern:

  • Industrial waste heat recovery for power production, focusing on low/medium temperature (below 200oC). Promising sectors are food, paper, and chemical industries.
  • Enhancing energy efficiency in ships by exploiting the low-temperature waste heat, with the use of heat pumps for heating or an ORC for power production, with the aim to reduce the fuel oil consumption and the emissions.
  • Reversible heat pump/ORC for flexible operation under both operating modes, with possible application in the domestic sector as well.
  • Combining renewables for heating, cooling and electricity based on the use of heat pumps in the buildings sector.
  • Energy/heat management, advanced simulation, and process control in complex systems.

Funding Sources

Industrial Adjunct Researcher project co-funded by Stavros Niarchos Foundation and the industrial partner G. Ligeros & SIA OE (Psyctotherm).


Dr. George Kosmadakis

+30 210 6503700