Data in Brief Paper (2020)

Paper published in Data in Brief Journal (2020)

Title: Data collected by coupling fix and wearable sensors for addressing urban microclimate variability in an historical Italian city

Language: English

Authors: Benedetta Pioppi (*a), Ilaria Pigliautile (*a), Anna Laura Pisello (*a,b)

*a: CIRIAF – Interuniversity Research Centre on Pollution and Environment Mauro Felli, Perugia, Italy
*b: Department of Engineering, Perugia, Italy

Abstract: This article presents the data collected through an extensive research work conducted in a historic hilly town in central Italy during the period 2016-2017. Data concern two different datasets: long-term hygrothermal histories collected in two specific positions of the town object of the research, and three environmental transects collected following on foot the same designed path at three different time of the same day, i.e. during a heat wave event in summer. The short-term monitoring campaign is carried out by means of an innovative wearable weather station specifically developed by the authors and settled upon a bike helmet. Data provided within the short-term monitoring campaign are analysed by computing the apparent temperature, a direct indicator of human thermal comfort in the outdoors. All provided environmental data are geo-referenced. These data are used in order to examine the intra-urban microclimate variability. Outcomes from both long- and short-term monitoring campaigns allow to confirm the existing correlation between the urban forms and functionalities and the corresponding local microclimate conditions, also generated by anthropogenic actions. In detail, higher fractions of built surfaces are associated to generally higher temperatures as emerges by comparing the two long-term air temperature data series, i.e. temperature collected at point 1 is higher than temperature collated at point 2 for the 75% of the monitored period with an average of þ2.8 [1]C. Furthermore, gathered environmental transects demonstrate the high variability of the main environmental parameters below the Urban Canopy. Diversification of the urban thermal behaviour leads to a computed apparent temperature range in between 33.2 [1]C and 46.7 [1]C at 2 p.m. along the monitoring path. Reuse of these data may be helpful for further investigating interesting correlations among urban configuration, anthropogenic actions and microclimate variables affecting outdoor comfort. Additionally, the proposed dataset may be compared to other similar datasets collected in other urban contexts around the world. Finally, it can be compared to other monitoring methodologies such as weather stations and satellite measurements available in the location at the same time.

Fourth Assembly in Bordeaux

Bienvenue a Bordeaux! The most elegant city in France! Last week we were at the Geofit 4th General Assembly where we had the chance to share all the advances achieved since the last meeting.

We managed to get into intense planning and discussing agenda, mostly related to very important issues regarding the implementation of the pilots and how the technical solutions and legal issues could be approached. 

We found out, for example, of an interesting opportunity involving the different types of soils in the five different pilot sites. Drilling on different soils are options that can be explored and harnessed for the project interests.

The assembly also dealt with technical issues that will affect the activities scheduled for the next six months.

 

 

We also visited the demo site in Talence, in the very same building where we carried out the meeting. Our host (SAED) kindly showed the space where the future Geofit installation will be placed. It was almost as being on a living lab! Technical discussions and problem solving for the heat pump installation were part of the second day too.

 

 

 

 

The weather wasn’t very inspiring but we managed to get a very clear path for the next six months and everyone left with a positive feeling facing the new work roadmap. Merci la France!

 

 

 

D4.1 – Options and selections of heating/cooling components for geothermal retrofitting

This report provides description of the modelling work conducted on the pilot sites of Perugia and Sant Cugat. The pilot sites, the studied heating and cooling systems and the used modelling software are described. Suggested low temperature heating and high temperature cooling system designs are simulated and in the case of Sant Cugat, the results are compared with the current situation and a comparable alternative. The results are presented and discussed.

In the pilot site Perugia, the model was created to be used as a design tool by other partners in the project. In the pilot site Sant Cugat, the simulations show that for the primary school a low temperature heating system coupled with mechanical ventilation would improve indoor air quality with heating demand similar to the current system. For the sports pavilion a clear preference could not be established. The results also show that a high temperature cooling system would be a viable alternative for the administrative building and drastically reduce thermal discomfort. Finally, it was found that a comparative state-of-the-art all-air system that would achieve similar comfort would result in higher heating and cooling demand in all cases. The future works in this task will include work on the Aran Islands pilot.

BS Rome – IBPSA Paper (2019)

Presentation of GEOFIT at BS ROME – 16th IBPSA International COnference and Exhibition (2019)

Title: Environmental sustainability and Energy Efficiency in Historical Buildings: GeoFit Project Implementation in the Case Study of a medieval fortress in Perugia

Language: English

Authors: Jessica Romanelli (*1), Matteo Di Grazia(*1), Cristina Piselli (*1,2), Anna Laura Pisello (*1,2), Franco Cotana (*1,2)

*1: CIRIAF – Interuniversity Research Centre, University of Perugia, Italy
*2: Department of Engineering, University of Perugia, Italy

Abstract: Italian cities are mainly constituted by buildings constructed until the mid-20th century by pre-industrial construction techniques. A HVAC system for the energy retrofit of historical buildings is evaluated when applied in the case study of Sant’Apollinare. It consists of a ground source heat pump a water tank for thermal energy storage connected to a low-temperature radiant system and air handling unit. The building thermal-energy behavior, typically influenced by thermal inertia in historical buildings, and the novel HVAC system performance interactions are comparatively assessed together with more traditional scenarios. Energy demand decreases by about one third compared to the pre-retrofit situation.

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.