The GEOBIM Platform

In the GEOFIT project, heating and cooling components design and integration are developed for the different layouts and demo-sites and comprise a detailed design and description of the different subsystems or components to form a complete system. Key elements and components, as well as their specifications, are being developed and inventoried as part of the GEOFIT project activities. As in previous work, the deployment of low-invasive risk assessment, site-inspection, and worksite-building monitoring techniques extend its use as a monitoring tool for geothermal based retrofitting operations and deploy novel tools enabling the view of assets in a cartographic or a geographical environment and comparing with the information stored into GIS collectors and the Web Map Services (WMS). A common data environment containing GIS/BIM models/sensor data allows users to locate, map, update and share objects and subsurface utility information simultaneously, contributing to the realization of a new “GEOBIM platform”. The objective of the GEOBIM platform is to assess and verify the integration of the GEOFIT solutions in specific cases developing the respective different BIM models over a geographical information layer, aiming at replication and modularity of the solutions, outputs for exploitation, impact assessment, and dissemination of the results. The implementation of the previously defined system is addressed for buildings with different typologies and energy demands. Then, integration of the conditions and the building’s engineering specifications are defined within the GEOBIM platform.

The GEOBIM platform considers the scalability and flexibility of the data integration and analysis tools development to support interoperability among the elements installed. The design inputs come from:

    1. Boreholes and ground excavations information
    2. Geothermal heat exchangers designs
    3. Ground source heat pumps designs
    4. Heat pumps designs
    5. Heating and cooling systems designs
    6. Sensors information
    7. Simulations data

By covering the 7 dimensions of the #BIM approach, the GEOBIM platform implements the following functions:

  • Project visualization
  • Data management
  • Demo-site analysis functions
  • Geothermal performance
  • Heating/Cooling performance
  • GEOFIT assets management
  • CAPEX
  • The lifecycle of systems and assets

Within the GEOBIM platform development (understood as a common data environment), model-based cooperation is the advanced portrayal of the general GEOFIT development process. This portrayal is made in collaboration with the different partners involved in the design, modeling, construction/fabrication, installation, and commissioning, who utilize different CAD-based tools. The Common Data Environment (CDE) is characterized as a typical advanced task space, which gives very much characterized collaborative territory to the undertaking partners joined with clear status definitions and a strong work process portrayal for sharing and endorsement forms and objects data.

Written by Sergio Velasquez, from IDP

Want to learn more?

Click on this link to have a look a the 10 Geobim videos posted on the project’s Youtube channel and thank you for watching!

Videos produced by COMET

 

D3.2 – Ground Source Heat Exchanger design framework

The goal of WP3 is to develop a design framework for novel ground (slinky/earth basket) type shallow heat exchangers. This design framework, based on developing theoretical models of heat transfer and on experimental data, will be implemented in a design- and engineering calculation tool to support the implementation of these new technologies in the market.

The design framework defines the goals of the (thermal and hydraulic) design (especially sizing) of the ground source heat exchanger, as a function of different boundary conditions (building energy demand, soil thermal parameters, required system performance etc.). Moreover, an engineering tool it is aimed at the overall system design and will support the engineer in the choices of heat exchanger technology (vertical, horizontal or earth basket/slinky) and other design parameterizations.

This deliverable describes the overall design process and provides information and procedures for data collection and evaluation. The detailed description of the design process for different types of Ground Heat Exchangers is based on the design of the actual GHEX systems implemented in the demo sites of the Geofit project and includes vertical borehole heat exchangers, shallow slinky heat exchangers and earth basket type heat exchangers.

This deliverable is suited to be implemented in a design handbook or procedure that can be part of an integrated quality control system.

D3.1 – Design methodologies strengths and weaknesses

In this deliverable the main fundamental processes of heat transport relevant to the ground heat exchangers have been described. For the purpose of the project, only heat transport due to conduction will be considered in detail.

There is abundant literature concerning methods to calculate the thermal response of ground heat exchangers and design. Using a few selected references an introduction to analytical and numerical methods is presented. A description of the different implementations of analytical and numerical modeling and design software codes is presented as well.

The different methods are classified for strengths and weaknesses based on criteria including methodology, complexity, number of input parameters required, processes considered, flexibility with regard to geology and parameters relating to the actual ground heat exchanger. The aim has not been to arrive at a ranking, but only at an overview of the capabilities of the codes and the ease or complexity of use. Cost is of course also an important aspect but is currently not included.

Based on the overview of different methodologies and implementations a roadmap for the development of the GHEX engineering tool within the work package has been defined. This roadmap is based on the expertise of the different partners and works from a detailed level, using the results to derive simplified models that can be integrated into a final engineering design tool.

Drilling bit materials for an improved performance

by Montse Vilaseca, EURECAT

Drilling is a key technology enabling heat exchangers installation and plays an important role in the building industry, both in sedimentary as well as in rock drilling. Tools employed in drilling are known as drill bits, and are the responsible for mechanically penetrating and crushing the rock underneath them. The wear of drilling tools has always been a predominant factor for the costs of geotechnical engineering measures and hard rock excavation. This fact is not only related to material and personnel costs arising from drill bit maintenance and replacement but also because of the direct and negative impact of wear on the drilling performance of a worn drill bit. Improper selection of a bit results in lower penetration rates, fast wearing of the teeth and frequent bit changes, which results in higher drilling costs overall.

Drilling is a key technology enabling heat exchangers installation and plays an important role in the building industry… Improper selection of a bit results in lower penetration rates, fast wearing of the teeth and frequent bit changes, which results in higher drilling costs overall.

During the first year of GEOFIT project representative tools from vertical and horizontal drilling operations (needed in the different pilots of the project) have been selected and provided by CDP after their end life. For vertical drilling, down to the hole hammer and drag bits have been studied. For horizontal drilling, tricones (crushers) have been selected. Drill bit materials and main damaging mechanisms have been characterized and identified in Eurecat aiming to select alternative materials and solutions in order to:

    • reduce drilling times
    • improve rate of penetration (ROP)
    • improve abrasion and chipping/spalling resistance of drill bits

 

Figure 1. Analysed drill bit.

 

Drill bit inserts are commonly made with cemented carbides (also named hardmetal, cermets or cemented carbides), which are sintered composite materials consisting of two phases called hard phase (WC) and binder phase (Co). This combination of hardness and toughness makes WC-Co a successful material in drill bit inserts. However, the mechanical properties of the material are strongly dependent on composition and structure. A high Co content gives a tough material and high WC content gives a hard but brittle material. In addition, WC grain size and carbon content affect the properties.

Cemented carbide buttons are inserted and/or soldered into holes of a steel tool body. Taking into account the main damage mechanisms identified in hard metal buttons of drill bits for GEOFIT project and looking into recent publications and developments, advanced alternative hard metal grades have been selected to improve their tribo-mechanical properties based on (i) varying the grain size of the hard phase and the binder content, named Dual properties (DP) and (ii) macro gradients of Co-migration. In the same manner alternative steels with high strength, high wear resistance, good toughness and good dimension stability specially designed for drilling applications have been selected. These alternative hard metal and steel grades are being systematically tested in Eurecat laboratory in order to obtain a classification of their tribological behavior (friction and wear resistance).

Wear tests have been designed in order to reproduce the same damaging mechanisms observed in drilling tools. Cemented carbide discs are slid against quartz and other abrasives used as counter parts. Quartz content of rock is one of the main geomechanical parameters influencing wear of drill bits. Test conditions (pressure, speed and time) have been adjusted until the same wear mechanisms have been obtained. Figure 2 compares surface of drill bit button from a tool and of a wear scar obtained in the lab, in both cases surface cracks, carbides deformation and adhesion of ore material are identified.

Figure 2. Scanning electron microscopy images (10,000 X magnification) of surfaces from a) worn drill bit button and b) wear scar from laboratory test.

 

Taking into account the main damage mechanisms identified in hard metal buttons of drill bits for GEOFIT project, advanced alternative hard metal and alternative steels grades have been selected to improve their tribo-mechanical properties and are being systematically tested in Eurecat laboratory in order to obtain a classification of their tribological behavior (friction and wear resistance).

Main results obtained in laboratory wear tests are:

    • Coefficient of friction: describes the interaction between drill bit material and rock material.
    • Wear rate: which is the worn drill bit material volume per sliding distance and applied force. Is obtained measuring wear scars (see Figure 3).

These are valuable parameters which are used to feed tool wear models that will predict tool live, models under development by LTU in the framework of GEOFIT project.

Figure 3. Wear scar topographic images corresponding to different grades of hard metal after wear tests under the same conditions (applied force, speed and time): G3 presents higher volume loss.