Low temperature deicing of road infrastructure using renewable energy

Winter road maintenance is costly but it is inevitable since it is necessary to keep roads accessible and safe during winter. Current winter road maintenance methods use annually 600 000 tons of salt, in the Nordic countries. The salt ends up in the environment along the roads and results in environmental challenges. This thesis proposes an alternative, winter road maintenance concept for critical parts of the road infrastructure. The proposed concept consists of a hydronic heated pavement (HHP), utilised as pavement solar collector (PSC), which is connected to a borehole thermal energy storage (BTES). The combination of an HHP and a BTES means that the solar radiation will be harvested in the summer time and the stored energy will be used for winter road maintenance. This system can be installed at critical parts of a road infrastructure. In existing hydronic pavements district heating or other high temperature energy sources are currently used, however, high temperature energy sources limit the implementation of HHP systems. Research on using low temperature energy sources can result in a reduction of primary energy need and makes implementation of HHP systems more feasible. The purpose of this thesis is to investigate the feasibility of implementing hydronic heated pavements using renewable energy, in the Scandinavian countries. This manuscript presents the experimental and numerical results from a field station of BTES connected HHP system. The field station was constructed during 2017 and experiments on harvesting were conducted during the summer of 2018. The anti-icing and de-icing function of the HHP system were studied during the winter of 2018/2019. The results revealed that the solar efficiency of the HHP system reach as high as 42 % and 245 kWh/m2 of solar heat was harvested during the summer of 2018. This is a comparably high value for a pavement solar collector. The harvested energy were higher than the supplied heat (132 kWh/m2) during the following winter. However, the cold climate at the field station required supplementary heating since the BTES did not have the capacity to supply the required supply temperature of 7 degC to the HHP. The numerical simulations has reveald that by using a dew-point regulation and weather forecasting the energy consumption can be reduced by 62 % compared to a simple air temperature regulation. Based on the experimental and numerical results it can be concluded that it is feasible to design HHP systems to use low temperature (<10 degC) sources and at the same time achieve a substantial improvement of the surface conditions in a Scandinavian climate

Hydronic Pavement Heating for Sustainable Ice-free Roads

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

Reduction of Neuropathic and Inflammatory Pain through Inhibition of the Tetrahydrobiopterin Pathway

Human genetic studies have revealed an association between GTP cyclohydrolase 1 polymorphisms, which decrease tetrahydrobiopterin (BH4) levels, and reduced pain in patients. We now show that excessive BH4 is produced in mice by both axotom- ized sensory neurons and macrophages infiltrating damaged nerves and inflamed tissue. Constitutive BH4 overproduction in sensory neurons increases pain sensitivity, whereas blocking BH4 production only in these cells reduces nerve injury-induced hy- persensitivity without affecting nociceptive pain. To minimize risk of side effects, we targeted sepiapterin reductase (SPR), whose blockade allows minimal BH4 production through the BH4 salvage pathways. Using a structure-based design, we developed a potent SPR inhibitor and show that it reduces pain hypersensitivity effectively with a concomitant decrease in BH4 levels in target tissues, acting both on sensory neurons and macrophages, with no development of tolerance or adverse effects. Finally, we demonstrate that sepiapterin accumulation is a sensitive biomarker for SPR inhibition in vivo

Winter Road Maintenance using Renewable Thermal Energy

Winter road maintenance is costly but it is inevitable since it is necessary to keep roads accessible and safe during winter. Current winter road maintenance methods use annually 600 000 tons of salt, in the Nordic countries. The salt ends up in the environment along the roads and results in environmental challenges. This thesis proposes an alternative, winter road maintenance concept for critical parts of the road infrastructure. The proposed concept consists of a hydronic pavement (HP), utilised as solar collector, which is connected to a borehole thermal energy storage (BTES). The combination of an HP and a BTES (called renewable HP) means that the solar radiation will be harvested in the summer time and the stored energy will be used for winter road maintenance at critical parts of a road infrastructure. In existing hydronic pavements district heating or other high temperature energy sources are currently used, however, high temperature energy sources limit the implementation of HP systems. Research on using low temperature energy sources can result in a reduction of primary energy need and makes implementation of HP systems more feasible. The purpose of this thesis is to investigate the feasibility of implementing hydronic pavements using renewable energy, in the Scandinavian countries. This thesis studies how a BTES can be connected to a hydronic pavement, focusing on the design of the BTES. The studies are based on extensive literature reviews and numerical simulations considering the interaction between the hydronic pavement and the BTES. The studied systems have all been direct connected systems without supplementary heating such as boilers or heat pumps. The results revealed that BTES is a suitable thermal storage technology to be used in combination with renewable HP. The renewable HP systems are mostly suitable for areas with mild winters. For locations with harsher climates there is a need for supplementary heating or increased number of boreholes in the BTES. The studied locations of Tranarp and Studevannet revealed that the renewable HP system can reduce the annual number of hours with risk for ice formation from 400 hours and 855 hours, to 6 hours and 23 hours respectively. However, in order to reach low risk levels, further development of control systems will be needed

Valbara kurser : Ett alternativ till områdesfördjupning inom sjökaptensprogrammet

Det här är en undersökning om studenters intresse för en områdesfördjupning på sjökaptensprogrammet på Kalmar Sjöfartshögskola. Syftet var att undersöka intresset hos studenterna kring att introducera valbara kurser om 7,5 högskolepoäng i programmets senare del. Den allmänna uppfattningen inom svensk sjöfart är att sjökaptensprogrammet på Kalmar Sjöfartshögskola är en bred utbildning.  Utbildningen erbjuder inga valbara kurser eller inriktningar även om arbetet som styrman idag blir mer och mer specialiserat. Studien genomfördes genom intervjuer med två studenter som gick sista året 2013 och tre verksamma styrmän som tagit examen år 2012. Alla intervjuade respondenter hade läst eller läste vid intervjutillfället på Sjökaptensprogrammet på Kalmar Sjöfartshögskola. Studien visade på en önskan hos respondenterna vad gällde ökad valbarhet i utbildningen, men samtidigt en ovilja att kompromissa utbildningens bredd. Respondenterna underströk vikten av möjligheten att få läsa CCM och DP-Basic, dels för en förbättrad konkurrenskraft på en ansträngd arbetsmarknad och dels för att de kurserna ofta krävs inom den arbetsmarknadssektor som ett stort antal studenter söker sig till. This is a survey of students' interest in an area specialization in the Nautical Science program at Kalmar Maritime Academy. The aim was to investigate the interest within the student community regarding introducing elective courses of 7.5 credits in the second half of the program. The general opinion in Swedish shipping is that the nautical science program at Kalmar Maritime Academy is a broad education. The program has no elective courses and specializations available; this at a time when the work as an officer is becoming more and more specialized. The study was conducted through interviews with two final year students of 2013 and three active officers who graduated in 2012. All respondents who were interviewed had studied or were studying at the time of the interview at the Nautical Science program at Kalmar Maritime Academy. The study showed a desire among the respondents regarding increased eligibility in the program but also unwillingness to compromise the width of the education. The respondents emphasized the importance of having the possibility to study CCM and DP-Basic, partly for an improved competitiveness in a strained labor market and partly due to fact that these courses are often required within the employment sector to which a large number of students will approach

Modelling and evaluation of groundwater filled boreholes subjected to natural convection

One of the challenges of designing ground source heat pumps systems is the calculation of the effective thermal borehole resistance which affects the heat extraction rate and thereby the required length of the borehole. Calculating effective borehole resistance is especially demanding when the boreholes are filled with ground- water. The natural convection in the groundwater affects the heat transport from the borehole heat exchanger to the borehole wall. The objective of this paper is to present the results of the modified Pygfunction software in which recently developed correlations for calculating influence of the natural convection in boreholes has been incorporated. The calculated results were validated by using results of thermal response test (TRT) from four adjacent groundwater filled borehole in the central parts of Sweden. The numerical results reveal that the ori- ginal and unmodified Pygfunction can be used for accurate calculation of fluid temperatures in borehole heat exchangers by using an effective thermal conductivity of the filling material. However, that requires access to thermal response test data. The modified software calculates the effective borehole resistance with a deviation of about 15–30% compared to the effective borehole resistance from TRT. This deviation is an improvement compared with the standard assumption of neglecting natural convection in boreholes. However, for large in- stallations with more than 4000m of borehole heat exchangers a thermal response test is still recommended in order to ensure a more correct sizing of geothermal system

A numerical and experimental study of a pavement solar collector for the northern hemisphere

Solar energy is a renewable energy source that is globally available. To utilise this type of energy, novel tech- nologies are developed across the globe. Among these, the pavement solar collector (PSC) technology has a considerable potential. A PSC consist of pipes, that are embedded into the upper pavement layers through which fluid is circulated. Solar radiation heats the pavement surface, and the absorbed heat is transferred to the cir- culating fluid. One applications is to use the heat for recharging shallow geothermal boreholes with solar energy during summer, thereby reducing the electricity consumption of ground source heat pumps during winter. In Scandinavia, however, the knowledge on the PSC application is limited. The Swedish transport administration has therefore established a field station to gain more insight on the PSC in Scandinavia. This paper reports the findings of the investigation from the summer of 2018 and how the efficiency of the PSC is affected by altering the albedo, fluid flow rate, and pipe spacing. The measured harvested energy is 245 kWh/m2 with a solar efficiency of 42%. It is found that by altering the albedo and flow rate, the efficiency could be enhanced by up to 49%. This high efficiency achieved in this study is dependent on the short pipe spacing of 5 cm and results in surface condensation on several occasions. Condensation on PSC has not been reported previously but should not pose a risk to road traffic because surface temperatures are above freezing

Modeling the thermal performance of low temperature hydronic heated pavements

Winter road maintenance is costly but it is necessary in order to keep roads accessible and safe during winter. Current winter road maintenance methods use 600,000 tons of salt annually, in the Nordic countries. The salt ends up in the environment along the roads and results in environmental challenges. Alternative winter maintenance methods that use heat instead of salt are in use today. However, those systems are designed to use high temperature of about 20–35 \ub0C. This paper presents a numerical model for designing low temperature (4–8 \ub0C) hydronic heated pavements (HHP). The model is validated against an experimental setup and different control strategies are evaluated. The validation indicated that the developed model can predict the behavior of the HHP with a root mean square error (RMSE) <1.4 \ub0C for surface temperatures and <0.4 \ub0C for the return fluid. In this paper the model is used with two different control strategies. A basic strategy controlling the system based on air temperature and one strategy based on dew point temperature. With dew point regulation the energy consumption can be reduced by 62%. However, the energy consumption is still in the range of 125–180kWh/m 2 for the location of 6stersund, Sweden. We found that the HHP system can utilize low temperature sources like waste energy or geothermal energy that is freely available. By using renewable energy for winter road maintenance, the environmental impact from winter road maintenance can be reduced