Meet our partners: Oschner

This interview is part of a series! You can see all our partner interviews here.

Ochsner Wärmepumpen (OCHSNER) was founded in 1978 as one of the first companies in Europe to produce heat pumps on an industrial scale, being a well-known producer of innovative heat pump systems covering all types of heat sources and capacities ranging from 2 to 1.600 kW.

In GEOFIT, they are responsible for several innovations with regards to optimising the design of heat pumps. These innovations have never been applied in heat pumps design and sizing and they will allow to decrease the environmental footprint while in parallel making heat pumps more affordable so that they can compete against non-renewable technologies.

One of the innovations, in collaboration with AIT, regards the design of an innovative, electrically-driven heat pump system with low/medium GWP synthetic refrigerant, which in turn makes a more cost-effective use of heat exchangers (HEX). They have also contributed to new methods to calculate heat pump sizing requirements which have been implemented within the IDDS framework used to design our pilot sites. This new methods will prevent oversizing of the heat pump component in geothermal systems which often results in non-optimal efficiencies/return on investment and can decrease the competitiveness of geothermal technologies with respect to competing systems.

These innovations have never been applied in heat pumps design and sizing and they will allow to decrease the environmental footprint while in parallel making heat pumps more affordable so that they can compete against non-renewable technologies.

In this interview, Oschner founder Dipl. Ing. ETH Karl Ochsner talks about the benefits of using the heat pumps in geothermal retrofitting, how projects like GEOFIT can connect themselves to the European Heat Pump Association (EHPA), and its impact on the market and the environment.

Model development and performance analysis of Novel Shallow Ground Heat Exchangers

by Henk Witte – Groenholland

One of the key aspects of the EU GEOFIT project is the development of integrated engineering design tools for different types of ground heat exchangers. This toolkit provides design methodologies for vertical borehole heat exchangers, shallow horizontal and slinky type heat exchangers, and earth basket (spiral) heat exchangers.

Ground heat exchangers (GHEX) are used to provide a heat source or heat sink used for heating or cooling a building. They are typically constructed of plastic pipes installed in different configurations in the ground. A fluid is circulated in the pipes and the GHEX extracts heat from the ground (heating operation) or rejects heat to the ground (cooling operation).

For the validation of the analytical solutions used in the integrated engineering design toolkit, especially the new finite line source solutions developed for earth basket (spiral) heat exchangers laboratory experiments (figure 1) and detailed numerical simulations (figure 2) have been performed.

Figure 1. Experimental sandbox setup for earth basket (spiral) heat exchanger characterisation (foto: AIT)

The performance of a ground heat exchanger can be summarized to two key parameters:

  1. Pressure drop: A measure of the pump energy needed to move the fluid through the heat exchanger.
  2. Thermal resistance between fluid and ground: A measure of the thermal performance of the GHEX.
Figure 2. CFD simulation of earth basket (spiral) heat exchanger (foto: AIT).

The goal of the performance analysis is to identify key-design parameters affecting the overall system performance. Parameters investigated include:

  • Diameter of the earth basket (spiral) heat exchanger
  • Pipe diameter in relation to flow rate and pressure drop
  • Distance between adjacent rings in relation to total length and buried depth
  • Soil thermal parameters

Evaluation of the results of the performance analysis should take into account the actual effect on system performance. As an example, it can be attempted to reduce the thermal resistance in all cases as much as possible. However, the effect on performance is related to the actual heat rate of the system (figure 3). It is clear that with a low heat rate (5 W/m) the thermal resistance can be allowed to be high without affecting performance. These results will have implications for operating these systems during part-load conditions, which is important in view of the application of frequency-controlled compressors in the heat pumps. In this way, the results of the GEOFIT project not only provide designers with the tools to evaluate different types of ground heat exchangers in one integrated tool but also allows optimization of actual system operational control.

Figure 3. Relation between thermal resistance (fluid to ground) and energy performance degradation for different specific heat rates.

REFERENCES

Meeng, C.L (2020). Development of an engineering tool for the design of novel shallow ground heat exchangers – GEOFIT. MSc Thesis TU Eindhoven.

Dörr, C.J. (2020). CFD Analysis of Ground Heat Exchangers. MSc Thesis Montan Universität Leoben, Austrian Institute of Technology.

Kling, S. (2020). Experimental characterization of Helix-Type Ground Source Heat Exchangers Configurations for Developing a Standardized Design Tool. MSc Thesis FH Burgenland University of Applied Sciences, Austrian Institute of Technology.

We end May with our 7th General Assembly!

The GEOFIT consortium successfully held its 7th Virtual General Assembly on May 20 and 21 2021, our first GA for 2021! The meeting was organised online in two intense half-day sessions during which work package leaders where able to present the progress made with the core technologies, demonstration activities and coordination work packages.

Kicking-off our 7th meeting!

The first-day session started with a focus on the state of the art of technical work packages (WP). Lead by our colleagues from IDS Georadar, Groenholland, AIT, and Nuig Galway, we got to review WP2 which focused on-ground research, worksite inspection, and improved drilling technologies, and wrapped up its work last April 2021. The presentations for WP 3, 4, and 5 presented the different advances made with our Shallow Ground Heat Exchangers, Heat Pumps, system integration and efficiency management. After a short coffee break, we had the presentation of the progress of pilot implementation. In this sense, we were celebrating the commissioning of our first pilot site in Perugia, an important milestone for the project! Our Bordeaux pilot has also taken important steps in the past months when it comes to drilling.

The GEOFIT Team

On the second day, we were able to review the advances made on our GeoBIM platform and the standardisation, exploitation, and communication activities and R2M started an open discussion on possible business cases, UNE presented different approaches to the standardisation language including the CWA and COMET updated on the most recent events and the new website design and materials.

The meeting wrapped up with high hopes that next time we might meet again in person and with a clear view of the next steps that will be taken by all partners during the next 6 months.

Structural Building Monitoring in the Drilling Phase

By Lucia Faravelli – SIART

The EU GEOFIT project comes with the goal, among others, of linking three main characters: the geothermal technology promoter, the excavation and drilling operator and the structural engineer. Within a geothermal based retrofitting of existing buildings, the first actor designs the geothermal system and dictates the main data to the excavation (drilling) works responsible. The latter one relies on earth moving machines that transfer vibrations to the soil and from here to the target building. The third character has the main role of supervisor that no damage affects the building during the plant installation.

The simplest policy would be to instrument the site and the building and to carry out a structural monitoring in the drilling phase. Currently artificial intelligence tools able to detect the incipient damage are not available. In other words, the deployed devices will only be able to detect and locate damage when this has already seriously progressed. The alternative feasible architecture goes across the knowledge of the excitation source, the identification of the vibration propagation across the soil and the understanding of the so-called building signature, i.e., the building own frequencies. The trick is to avoid amplifications in the pattern from the source to the building of those frequencies to which the building is sensitive. Along this path, the role of structural monitoring will simply be that of checking that the recorded (accelerometric) signals will confirm the numerical models.

Fig. 1 – Drilling activities at the Sant Cugat pilot

Knowledge of the excitation source. Figure 1 above, shows the drilling machine of one of the GEOFIT partners. Figure 2 below is the plot of the vertical component of the acceleration as recorded by an accelerometer on the machine. Finally, Figure 3 gives a plot of the same vertical component of the acceleration as recorded by an accelerometer on the soil nearby the machine. It is worth noticing the differences between the two ranges of intensity.

Propagation across the soil interface. The phenomenon is covered by reliable scientific software adopting sound mechanical models [2]. The role of the monitoring is to confirm that the recorded output is consistent with the model. In other words, there should not be amplification in the frequencies to which the building is sensitive. Building signature. This aspect can easily be solved by carrying out the structural monitoring in a pre-drilling stage [3].

Fig. 2 -Vertical component of the acceleration as recorded on the drilling machine (time in
seconds; intensity in V; conversion 1V = (1/2.5)g). Zoom on the right.
Fig. 3 – Vertical component of the acceleration as recorded on the soil near-by the drilling
machine (time in seconds; intensity in V; conversion 1V = (1/2.5)g). Zoom on the right.

References

[1] Casciati S.; Chen, Z., A multi-channel wireless connection system for structural health monitoring applications STRUCTURAL CONTROL & HEALTH MONITORING Volume: 18 Issue: 5 Pages: 588-600 Published: AUG 2011

[2] Casciati, F.; Faravelli, L.Dynamic transient analysis of systems with material nonlinearity: a model order reduction approach SMART STRUCTURES AND SYSTEMS Volume: 18 Issue: 1 Pages: 1-16 Published: JUL 2016

[3] Casciati S., Stiffness identification and damage localization via differential evolution algorithms, STRUCTURAL CONTROL & HEALTH MONITORING Volume: 15 Issue: 3 Pages: 436-449 Published: APR 2008

Novel particle-based drill modelling by LTU

Using numerical modelling for simulating manufacturing processes and predicting final properties is more or less mandatory in many industries. However, it is barely used within the rock drilling market despite being a powerful and cost-efficient method.

This is why GEOFIT will introduce a novel particle-based finite element method for modelling the drilling and excavation process. With this new approach, we aim to assist operators in choosing optimum drilling parameters and tools to reduce wear These simualtions will then be validated by comparing the outcome with the data from some of the pilots.

They key strength behind these simulations is their potential to simulate the rock fragmentation processes. The rock material will be mechanically characterized and finally the numerical approach will be validated by comparing the outcome with the data from some of the pilots.

In this video below you can see some of the numerical simulations developed up to date by the group at the Division of Mechanics of Solid Materials of Lulea University of Technology (LTU) for the GEOFIT project.

Still curious about our drilling innovations? Make sure to read EURECAT’s article on their work on Drilling Bit Materials for an Improved Performance.

Marco Calderoni elected as New Chair of the RHC-ETIP

GEOFIT project coordinator, Marco Calderoni, was elected as new chair of the RHC-ETIP, the European Technology and Innovation Platform on Renewable Heating and Cooling. His mandate started on the 1st January 2021 and will run until the end of 2021. The RHC-ETIP represents stakeholders from the biomass, geothermal, solar thermal sectors, heat pumps, district heating and cooling, thermal storage and hybrid systems. It is, therefore, a unique ETIP covering all the renewable heating and cooling technologies.

Marco Calderoni takes over for Javier Urchueguía, RHC-ETIP Chairman in 2020. As key takeaways from his presidency period, Dr.Urchueguía pointed out the influential role of the RHC-ETIP to tip the balance of the budgetary distribution towards renewable heating and cooling. During his first meeting as Chairman of the RHC-ETIP, Marco Calderoni highlighted the potential positive impact of new alliances formed in 2020, such as the one with ETIP SNET and the Clean Energy Transition Partnership.

GEOFIT is already part of their project database and is now closer to the RHC Platform that it has been so far. Thus we can indirectly contribute to their work of maximising synergies and strengthening efforts towards research, development and technological innovation of Geothermal Energy within the European Union.

You can now read the full press release from RHC-ETIP here.

GEOFIT at Sustainable Places 2020

On Day 3 of the 4-day virtual Sustainable Places 2020 (SP2020) conference, Thursday 29th October from 14.00 – 17.00 CET, Marco Calderoni from GEOFIT contributed to the “Renewable Heating and Cooling Solutions for Buildings and Industry Workshop”, and the presentations and video recordings are publicly accessible.

Banner for “Renewable Heating and cooling solutions for Buidlings and Industry” at SP2020

The workshop brought together a selection of H2020 EU-funded projects involving experts from the biomass, geothermal, solar thermal and heat pump sectors to discuss a common strategy for increasing the use of renewable energy technologies for heating and cooling for buildings and industry. Renewable energy technologies for heating and cooling are safe, clean, efficient and increasingly cost-competitive. The workshop comprised four thematic sessions, namely “RHC for industrial applications”, “Storage solutions for RHC support in buildings”, “Innovative solutions for RHC deployment in buildings”, and finally the one that GEOFIT presented in called “Demonstration actions for RHC in buildings”.

Marco Calderoni from R2M Solution presented the GEOFIT project and highlighted first lessons learnt based on experience at the five demonstration sites.

R2M Solution organizes the annual international Sustainable Places conference, and the recent 8th as usual focused on the built environment at building, district, and urban scales to include our transport and energy infrastructures. Renowned for showcasing results coming out of the EU Horizon 2020 Framework Programme via the participation of cutting-edge research and innovation projects, the scope of Sustainable Places is captured directly in its name. It involves designing, building and retrofitting the places we live and work in a more sustainable way.

A GEOFIT poster was also displayed in the virtual room of Sustainable Places 2020.

Participating projects wereSWS-Heating – HYBUILD – CREATE – TRI-HP – HYCOOL – SHIP2FAIR – SUNHORIZON – Heat4Cool – GEOFIT – SCORES – Innova microSolar – Hybrid BioVGE – RES4BUILD – SolBioRev – FRIENDSHIP

Chair of the workshop: Andrea Frazzica (CNR ITAE) – partner of GEOFIT