| 1. |
- Adl-Zarrabi, Bijan, 1959, et al.
(författare)
-
Annex 65, Long-Term Performance of Super-Insulating-Materials in Building Components and Systems. Report of Subtask III: Practical Applications – Retrofitting at the Building Scale – Field scale
- 2020
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- More than 80% of the energy consumption will be influenced by the existing building stock. Accordingly, building renovation has a high priority in many countries. Furthermore, several studies have shown that the most efficient way to curb the energy consumption in the building sector (new & existing) remain the reduction of the heat loss by improving the insulation of the building envelope (roof, floor, wall & windows). All since the first oil crisis in 1973-1974, the national building regulations require improvement of the thermal performance of the building envelope to significantly reduce the energy use for space heating. Following the regulations, the energy efficiency of new buildings has improved. In Europe, targeting to an average U-value close to 0.2 W/m2·K is optimal. Using traditional insulation materials this means an insulation thickness of about 20 cm. Thus, the thickness of internal and/or external insulation layers becomes a major issue of concern for retrofitting projects and even for new building projects in cities. Therefore, there is a growing interest in the so-called super-insulating materials (SIM). The scope of the present work covers two different types of SIMs: • Advanced Porous Materials (APM), where the gaseous heat transfer is hindered significantly by the fine structure in the sub-micrometre range, and • Vacuum Insulation Panels (VIP), where the contribution of gaseous conductivity to the total heat transfer is suppressed by evacuation. For Advanced Porous Materials (APM) one might distinguish between • porous silica e.g. based on fumed silica, and • aerogels. For Vacuum Insulation Panels (VIP) one might distinguish between: • different core materials: fumed silica, glass fibre, PU, EPS, others; • different envelopes: metalized film, aluminium laminate, stainless steel, glass, or combinations; • with or without a getter and/or a desiccant. The objective of this Annex 65 Subtask 3 report is to define the application areas of SIM and to describe the conditions of the intended use of the products. Indeed, it’s clear that the requested performance of the SIM will strongly depend on the temperature, humidity and load conditions. For building applications, storage, handling and implementation requirements are also described. Common and specific numerical calculations will be performed at the building scale to assess the impact of SIM on the performance of the building envelope. SIM was used in almost all building components with different environmental condition (boundary condition) and in different climate zone. The moisture and temperature conditions in building components can cause moisture/temperature induced stresses and the stresses can cause damage in sensitive super insulation material e.g. VIPs. Thus, to convince the conservative market of construction, it needs, in addition to laboratory measurements, real condition/environmental measurements of commercially realized objects (new buildings as well as refurbishments) under several years of operation. The long-term performance of super insulation materials has to be determined based on case studies in field and laboratory. Full scale experiments provide knowledge of practical and technical difficulties as well as data for service life estimation. For certain conclusions to be drawn from the case studies, monitoring is essential. Unfortunately, monitoring is only performed in few case studies. In this report these experiences are gathered and evaluated from a long-term performance perspective. APMs have been commercially successful in the building industry in niche applications typically with space restrictions since the early 2000s. Therefore, over the last years, a number of state-of-the-art reviews have focused on applications of advanced porous materials, such as aerogels, used as thermal insulation in buildings. VIPs, on the other hand, have also been used in other applications than buildings, such as refrigerators and transport boxes. The different applications areas have been identified by numerous researchers. However, in most studies of VIPs available in the literature, it was only the thermal performance of the assembly that was investigated. However, also the moisture performance is important to consider since changes to existing structures will influence the risk for moisture damages. In the Annex, the gathered case studies cover a wider range of SIM i.e. aerogel blankets, AB, (7 case studies), silica-based boards, SB, (3 case studies) and VIP (22 case studies). The aim was to gather information from projects where SIMs were used in different assemblies. Some of the projects have been monitored, i.e. sensors were installed to monitor the temperature, relative humidity or heat flux through the assemblies, while only three have been followed up, i.e. where a third party have analysed the results of the monitoring. The case studies are presented and specific and general conclusions from each application are made. The case studies showed that aerogel blankets are possible to install in up to five layers (50 mm) without too much difficulty. The evaluations showed that the performance of the aerogel blankets was maintained over the evaluation period. For VIPs, it is difficult to evaluate the performance when installed in the wall. In one of the case studies in the report, the external air space made it impossible to identify the different panels by thermography. Only indirect methods, like evaluation of the measured temperatures in the wall, can be used to follow the long-term performance of the panels. In another case study, hybrid insulated district heating pipes were installed at two locations in a district heating system with temperatures up to 90°C. Measurements during the period 2012 to 2015 showed no sign of deterioration of the VIPs and the temperature profile over the pipes was constant. An existing masonry wall was insulated with VIP-foam sandwich (XPS-VIP-XPS). It showed satisfactory and promising performance for a period of six years (2011-present). The analysis of the data obtained from continuous temperature monitoring across each insulation layer indicated the aging of VIP remains insignificant. In the framework of IEA EBC Annex 65 a common simulation-based procedure was introduced with the scope to identify potential critical hygrothermal working conditions of the SIM, which were identified as main drivers of the ageing effect. The study highlights that some physical phenomena (such as thermal bridging effects, the influence of temperature on the thermal conductivity and the decay of performance over time depending on the severity of the boundaryconditions) should be carefully evaluated during the design phase in order to prevent the mismatch between expected/predicted and the actual thermal performance. As general guidelines to mitigate the severity of the operating conditions of VIP, a list of recommendation are in the following summarised: • For the external wall insulation with VIP in solar exposed façade, the adoption of ventilated air layer could dramatically reduce the severity of the VIP operating conditions. Alternatively, light finishing colour are warmly encouraged to mitigate the surface temperature. • The protection of VIP with thin traditional insulation layer is always encouraged. • The application of VIP behind heater determines high value of surface temperature field which could potentially lead to a fast degradation of the panel. A possible solution to mitigate the severity of the boundary conditions could be the coupling of VIP with a radiant barrier, or the protection of VIP with thin insulation layer when it is possible. • In roof application, light colour (cool roof), performant water proof membrane, ventilated airspace and gravel covering layer (flat roof) represent effective solutions to mitigate the severe exposure. • In presence of wall subjected to high driving rain, it is preferable to adopt ventilated façade working as rain-screen to prevent the water absorption. Furthermore, to provide designers, engineers, contractors and builders with guidelines for the applications of vacuum insulation panels (VIPs) and Advanced Porous Materials (APMs) examples are given of methods that may be used to verify the quality and thermal performance of SIMs after installation. A comprehensive account of transport, handling, installation and quality check precures are presented. The main purpose of the descriptions is to promote safe transport, handling and installation. In the case of VIPs the primary issue is that of protecting the panels whereas the main concern for APMs is the safety in handling of the material. During the work of the Annex several questions regarding the long-term performance of SIMs on the building scale have been identified and discussed. Four main challenges were identified: • Knowledge and awareness among designers concerning using SIM • Conservative construction market • Cost versus performance • Long-term performance of SIMs Finally, SIMs for building applications have been developed in the recent decades. Theoretical considerations and first practical tests showed that VIP, especially those with fumed silica core, are expected to fulfil the requirements on durability in building applications for more than 25 years. Both VIPs and APMs have been successfully installed over the past 15 years in buildings. However, real experience from practical applications exceeding 15 years is still lacking, especially when considering third-party monitoring and follow up of demonstrations.
|
|
| 2. |
- Adl-Zarrabi, Bijan, 1959, et al.
(författare)
-
Determination of anisotropic thermal conductivity of VIP laminate using transient plane source method
- 2019
-
Ingår i: Proceedings of the 14th International Vacuum Insulation Symposium (IVIS2019). - 9784600002183 ; , s. 23-26
-
Konferensbidrag (refereegranskat)abstract
- The use of super insulation materials, such as vacuum insulation panels (VIP), is expected toincrease in buildings in the future. One key aspect for successful implementation is the qualitycontrol. At the factory, the thermal performance can easily be controlled by measuring theinternal pressure of the VIP. Preferably, the performance should be controlled again at theconstruction site before installation. The thermal conductivity of a VIP is possible to measureby using the transient plane source method (TPS). This method uses a sensor which measurethe temperature increase during a heat pulse. For the analysis of the measurement, informationon the thermal conductivity of the metalized multi-layer polymer laminate, used around the VIP,is needed. This paper presents the results obtained from different measurement setups of thelaminate. The aim of the study is to identify a practical approach to analyse the results, and togive recommendations on the best measurement setup. Two measurement submodules wereused; ‘anisotropic’ and ‘thin film’. The thermal conductivity of the laminate was measured inplaneand perpendicular to in-plane. The volumetric heat capacity was measured by differentialscanning calorimeter (DSC). The measurement results were compared to calculations. Theresults from the ‘anisotropic’ module was in best agreement with the calculated results. It wasalso illustrated that the TPS may be used for relative measurements to find damaged VIP.
|
|
| 3. |
|
|
| 4. |
- Adl-Zarrabi, Bijan, 1959, et al.
(författare)
-
Ground Source De-Icing and Snow Melting Systems for Infrastructure
- 2023
-
Ingår i: Transportation Research Procedia. - 2352-1465 .- 2352-1457. ; 72, s. 1621-1628
-
Konferensbidrag (refereegranskat)abstract
- Thermal de-icing and snow melting methods to control winter conditions on surfaces of transport infrastructure offer several advantages compared to conventional techniques. These include the automated control of safe surface conditions, avoidance of chemicals and their environmental impact and prolongation of the life span of the infrastructure. Hydronic heat transfer systems can take advantage of collection of solar energy mainly during summertime and seasonal storage of thermal energy by geothermal heat exchange. Making use of these renewable resources in combination with energy storage enables savings in primary energy. In June 2021, the International Energy Agency (IEA), initiated a project related to utilization of ground thermal energy sources for de-icing of surfaces in transport infrastructures. The present paper gives a first overview of the project goals and methods.
|
|
| 5. |
- Adl-Zarrabi, Bijan, 1959, et al.
(författare)
-
Hydronic Pavement Heating for Sustainable Ice-free Roads
- 2016
-
Ingår i: Transportation Research Procedia. - : Elsevier BV. - 2352-1465 .- 2352-1457. ; 14, s. 704-713
-
Konferensbidrag (refereegranskat)abstract
- Hydronic pavement is an alternative method for de-icing of roads. A hydronic pavement (HP) could be more environmental friendly than traditional de-icing methods such as salting. The HP system consists of embedded pipes in the pavement structure, with a fluid as energy carrier. The performance of a HP system strongly depends on a number of parameters e.g. the location of the pipes, the thermal properties of pavement structure and the temperature level of the heat storage system. In this paper initial results related to the designing of a HP system are presented.
|
|
| 6. |
- Adl-Zarrabi, Bijan, 1959, et al.
(författare)
-
Hydronic Pavement Using Low Temperature Borehole Thermal Energy Storage
- 2016
-
Ingår i: Advances in Civil, Environmental and materials research (ACEM16). - 9788989693444 ; , s. 14-
-
Konferensbidrag (refereegranskat)abstract
- Winter conditions on roads are a challenge for road administrators in cold climates and with increased public demands on safety, winter maintenance activities will increase. The most common winter maintenance activity in Scandinavia is anti-icing, which is performed when it is a risk for ice formation on the road surface. Commonly a truck is utilized for spreading freeze point depressant, like salt, on the pavement thereby lowering the freezing point and preventing ice formation on the surface. This method has been questioned for a number of reasons e.g. salts have negative effects on the local environment. An alternative method for de-icing is to use hydronic pavement (HP). HP consists of a pipe network, embedded inside the pavement, in which a fluid is circulated. The fluid collect solar energy during summer days and transports heat back to the road surface during icy winter days. The harnessed and released energy should be in balance, otherwise an additional heat sources is needed. This study has investigated the possibility of developing an alternative strategy to heat the pavement surface with stored low temperature fluids. By using the methodology, and software BRIDGESIM, a preliminary design of a hydronic pavement system have revealed that it is not feasible to design a system for the cold climate of Ö stersund (Sweden); only relying on harnessing solar energy and store the energy in a borehole thermal energy storage. However it was revealed that it is possible to design HP system for low supply temperatures of about 7 °C. Which is far below the supply temperature of about 35 °C, recommended by manufacturers of HP system. The prospect of utilizing low-temperature heat sources would make HP system more energy efficient which could make it an alternative to traditional winter maintenance methods.
|
|
| 7. |
- Adl-Zarrabi, Bijan, 1959
(författare)
-
Hygro-Elastic Deformation of High Pressure Laminates. A Macroscopic Analysis. Theoretical Modelling and Measurements
- 1998
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Deformation due to environmental changes in moisture arises in many engineering problems of practical interest. The purpose of this work is to develop a theoretical model for the determination of moisture induced deformations in thin plates made of High Pressure Laminates. For the determination of moisture induced deformations, a set of material properties is required. Measuring these properties is also a part of this work. The theoretical models for moisture transfer and elastic deformation are based on Fick's law and the Kirchhoff plate theory, respectively. High Pressure Laminates are classified as a composite material and the behaviour of composites can be analysed in different classes of theoretical problems. Here, the High Pressure Laminate is treated, on the macroscopic scale of observation, as a homogeneous, elastic and orthotropic material. A basic result of the thesis is a simple procedure to account for the effect of hygro-expansion. The moisture moment integral, which essentially is proportional to moisture content profile and thickness of plate, gives a basic time-dependent function I(t) which determines the effect of any uneven moisture distribution over the cross-section of the plate. The moisture-induced moments are proportional to I(t) and they only appear as an additional term in the boundary conditions of the plate. Solutions for simply supported plates are presented for different rectangular shape and, for different stiffness and hygro-expansion coefficients in the two orthotropic directions. Two PC-programmes, MHPL and MecHPL, based on the theoretical models are developed. MHPL deals with determining the moisture content of the material and MecHPL deals with calculating the moisture induced deformations in the plate. These programmes have been validated by using existing programmes and experimental tests. The results of the validations indicate that the models and PC-programmes are correctly formulated.
|
|
| 8. |
- Adl-Zarrabi, Bijan, 1959, et al.
(författare)
-
Högpresterande fjärrvärmerör
- 2012
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I ett fjärrvärmesystem är det viktigt att den producerade värmen levereras tillkonsumenterna med minsta möjliga förluster. Distributionssystemet ger upphov tillden enskilt största delen av värmeförlusterna under rörsystemets livslängd. Frågan omstorleken på värmeförlusterna har studerats alltsedan det första fjärrvärmesystemetbyggdes.Syftet med projektet är att undersöka nya material med avseende på deraslämplighet som isoleringsmaterial för rörsystemet. Det finns idag kommersiellttillgängliga produkter baserade på aerogel-kompositer och vakuumisoleringsteknikmed omkring två till fyra gånger så bra isoleringsprestanda som polyuretanisolering.Det finns dock i dagsläget inga material som är speciellt anpassade för rörsystemetPrototyper av hybridisolerade fjärrvärmerör med aerogel-filtar och vakuumisoleringspanelerhar tillverkats. Prototyperna har utvärderats i laboratoriemiljö ochmed hjälp av fältmätningar.Resultaten från undersökningen visade att aerogel-filtar och vakuumisoleringspanelervar kompatibla med polyuretanisolering och att det går att använda materialeni hybridisolering av fjärrvärmerör. En 10 mm aerogel-filt eller en 5 mm vakuumisoleringspanelförbättrar värmekonduktiviten hos röret (DN 100/225) med 15 %.En 10 mm tjock vakuumisoleringspanel ger en förbättring så stor som 30 %.Resultaten från fältmätningar med dubbelrör isolerade med vakuumpaneler ärännu inte kompletta men de befintliga temperaturmätningarna indikerar en klarminskning av värmeförlusterna.Projektet fokuserade på förbättring av rörsystemets termiska egenskaper. Detbehövs ytterligare forskning och utveckling för att kunna använda dessa material påett säkert sätt i ett fjärrvärmenät. Exempel på saker som måste undersökas ärlivslängden för de nya produkterna och ekologiska och ekonomiska aspekterrelaterade till de nya materialen.
|
|
| 9. |
- Adl-Zarrabi, Bijan, 1959, et al.
(författare)
-
Safe and Sustainable Coastal Highway Route E39
- 2016
-
Ingår i: Transportation Research Procedia. - : Elsevier BV. - 2352-1465 .- 2352-1457. ; 14, s. 3350-3359
-
Konferensbidrag (refereegranskat)abstract
- The project “Coastal Highway Route E39” have a mandate to, investigate how infrastructure can exploit renewable energy to reduce environmental footprint. Three PhD projects were initiated on this subject at Chalmers University of Technology by Norwegian public road administration. Results in this paper conclude that (1) Life Cycle Assessment should have a geographical dimension with respect to assumptions and input data, (2) there are substantial potential to reduce the CO2 emissions from the E39, especially when considering an electrification, and (3) the harvested energy from hydronic pavement system can be enough for maintaining ice-free roads in Nordic countries.
|
|
| 10. |
- Adl-Zarrabi, Bijan, 1959
(författare)
-
Super insulation material in district heating pipes
- 2018
-
Ingår i: IBPC 2018 Proceedings.
-
Konferensbidrag (refereegranskat)abstract
- In Swedish district heating systems, 10% of the produced energy is lost at the distribution network. It is of interest to lower the energy losses both for economic and environmental reasons. Since 2011 the feasibility of using superinsulation material for insulation of the district heating pipes were studied. Apparent thermal conductivity and long term performance of vacuum panels has been identified has the crucial challenge for using vacuum insulation panels. The estimated life time of a vacuum panel in building applications at 90 °C is about 50 years. The life time estimation is based on the climate condition valid for building application. However, peak temperature in a district heating system can be about 140°C. Hybrid insulated pipes with a Vacuum Insulated Panel (VIP) have been tested and evaluated by laboratory and field measurements. The results of numerical analyses of the measured data indicate a possible small degradation of the VIP at a similar rate as building application, even though the operative temperature is between 80-100 °C. In the laboratory a hybrid insulated pipe has withstood exposure to one sided heating at 115°C for over 5 years. The results indicate that hybrid insulated district heating pipes reduce heat losses by 20-30% for a twin pipe and with more than 50% in a single pipe. It can be concluded that VIP shows promising performance in district heating pipe applications.
|
|
