{"id":298,"date":"2026-09-01T13:31:10","date_gmt":"2026-09-01T13:31:10","guid":{"rendered":"https:\/\/hp2mix.dk\/?page_id=298"},"modified":"2026-09-08T12:13:52","modified_gmt":"2026-09-08T12:13:52","slug":"dtu-and-dti-test-zeotropic-mixtures-to-maximize-energy-efficiency","status":"publish","type":"page","link":"https:\/\/hp2mix.dk\/?page_id=298","title":{"rendered":"DTU and DTI test zeotropic mixtures to maximize energy efficiency"},"content":{"rendered":"\n
\"\"<\/figure>\n\n\n\n

DTU visits DTI to align on HP2MIX prototype and research activities<\/strong><\/h2>\n\n\n\n

Recently, researchers from DTU Construct visited Danish Technological Institute (DTI) in Aarhus, Denmark, for a technical meeting regarding the HP2MIX 20 kW prototype. <\/p>\n\n\n\n

The physical inspection of the unit complemented the ongoing numerical modelling work. Seeing the prototype first-hand allowed the DTU team to better evaluate the unit’s physical layout, instrumentation, and measurement capabilities. <\/p>\n\n\n\n

During the meeting, the partners discussed the progress of the laboratory tests and mapped out upcoming testing scenarios. The team also aligned on scientific dissemination, including plans for future conference papers and journal publications to share the project\u2019s findings with the energy and heat pump community. <\/p>\n\n\n\n

The visit was also a valuable opportunity to introduce Marwan Y A Abugabbara, who recently joined the DTU team to work on the advanced control systems in Work Package 5. He participated in the technical discussions alongside his DTU colleagues Jonas Kj\u00e6r Jensen and Roger Padull\u00e9s I Sol\u00e9, and DTI\u2019s specialists Wiebke Brix Markussen, Virginia Natonek, Pierre-Jean Del\u00eatre, and J\u00f3hannes Krist\u00f3fersson. <\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

DTU\u2019s research activities in HP2MIX<\/strong> <\/h2>\n\n\n\n

While DTI is responsible for the laboratory testing of the prototype, DTU Construct is a key research partner, delivering the theoretical and numerical models required to develop the technology. <\/p>\n\n\n\n

Using zeotropic mixtures instead of pure refrigerants can improve heat pump efficiency by up to 30 % by matching temperature glides.  <\/p>\n\n\n\n

To support this development, DTU is responsible for several core research tasks: <\/p>\n\n\n\n

1. Thermodynamic and Off-Design Modeling (WP1) <\/p>\n\n\n\n

DTU leads the initial stages of the project by developing steady-state and off-design numerical models. These models are used to screen and identify the optimal hydrocarbon-based mixtures for different industrial use cases, evaluating how the system will perform under varying, real-world operating conditions. <\/p>\n\n\n\n

2. Control Strategies for Zero-Superheat Operation (WP5) <\/p>\n\n\n\n

To maximize the efficiency gains from the zeotropic glide, the evaporator should ideally operate under zero-superheat conditions at the outlet. DTU is developing a dynamic simulation model of the entire heat pump in Dymola to test control strategies. This work ensures stable and safe compressor operation when operating without superheating, which is the main focus of Marwan Y A Abugabbara’s research. <\/p>\n\n\n\n

3. Compressor and Heat Exchanger Modeling (WP3 & WP4) <\/p>\n\n\n\n

Refrigerant mixtures behave differently than pure fluids, which introduces challenges for standard components: <\/p>\n\n\n\n

    \n
  • Compressor Performance: DTU is developing a generic model of a screw compressor to predict isentropic and volumetric efficiencies when using mixtures, including modeling how much refrigerant dissolves into the compressor oil. <\/li>\n\n\n\n
  • Heat Exchanger Optimization: DTU contributes its expertise in plate heat exchanger modeling to optimize the design, helping to compensate for reduced heat transfer coefficients while minimizing the flammable refrigerant charge. <\/li>\n<\/ul>\n\n\n\n

    4. In-Situ Composition Monitoring <\/p>\n\n\n\n

    Because different refrigerant components can dissolve into the compressor oil at different rates, the circulating mixture\u2019s composition may vary from what was initially charged. DTU is designing and building an experimental test setup to develop methods for real-time, in-situ monitoring of the circulating refrigerant composition. <\/p>\n\n\n\n

    Next steps<\/strong><\/h2>\n\n\n\n

    The collaboration between DTU’s modelling and DTI’s experimental setup is paving the way for the next phases of the project. The results from the 20 kW prototype will support the design and evaluation of the larger 500 kW pilot demonstration unit, which is scheduled for testing at DTI this autumn before being integrated at one of Innargi’s geothermal sites. <\/p>\n\n\n\n

    \"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

    DTU visits DTI to align on HP2MIX prototype and research activities Recently, researchers from DTU Construct visited Danish Technological Institute (DTI) in Aarhus, Denmark, for a technical meeting regarding the HP2MIX 20 kW prototype.  The physical inspection of the unit complemented the ongoing numerical modelling work. Seeing the prototype first-hand allowed the DTU team to better evaluate the unit’s physical layout, instrumentation, and measurement capabilities.  During the […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-298","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/hp2mix.dk\/index.php?rest_route=\/wp\/v2\/pages\/298","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hp2mix.dk\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/hp2mix.dk\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/hp2mix.dk\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/hp2mix.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=298"}],"version-history":[{"count":3,"href":"https:\/\/hp2mix.dk\/index.php?rest_route=\/wp\/v2\/pages\/298\/revisions"}],"predecessor-version":[{"id":310,"href":"https:\/\/hp2mix.dk\/index.php?rest_route=\/wp\/v2\/pages\/298\/revisions\/310"}],"wp:attachment":[{"href":"https:\/\/hp2mix.dk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=298"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}