Decrease of the maximum speed in highway tunnels as a measure to foster energy savings and sustainability

The high energy consumption of the lighting installations in highway tunnels has become a hot topic in the last few years due to the high figures in terms of money, consumed energy, use of raw materials, emissions of greenhouse gases due to the remarkable number of manufactured elements, and maintenance, among others. In spite of the different strategies proposed up to date and their savings, the potential benefits of decreasing the maximum speed allowed in tunnels have not been considered in depth as a complementary measure yet. In this work, the impact of such a decrease in terms of energy consumption, number projectors, carbon dioxide (CO2) emissions, and yearly costs in energy is analyzed and discussed. The results strongly suggest the convenience of introducing maximum speed reduction in traffic regulations which, in addition, could create positive synergies with traffic safety

Advances in Theoretical and Computational Energy Optimization Processes

Industry, construction and transport are the three sectors that traditionally lead to the highest energy requirements. This is why, over the past few years, all the involved stakeholders have widely expressed the necessity to introduce a new approach to the analysis and management of those energy processes characterizing the aforementioned sectors. The objective is to guide production and energy processes to an approach aimed at energy savings and a decrease in environmental impact. Indeed, all of the ecosystems are stressed by obsolete production schemes deriving from an unsustainable paradigm of constant growth and related to the hypothesis of an environment able to absorb and accept all of the anthropogenic changes

Benessere termoigrometrico in ambiente esterno ed interno: sviluppo di modelli predittivi, analisi di materiali innovativi e ripercussioni sui consumi energetici

Nell’ambito del presente lavoro di tesi sono stati investigati differenti aspetti legati al thermal comfort in ambiente interno ed esterno. Per quanto concerne gli ambienti aperti, sono stati sviluppati modelli predittivi della percezione termoigrometrica, è stata valutata l’influenza sul microclima di materiali innovativi e di varie strategie di mitigazione e si è proceduto a mappare, attraverso opportuni indici, il territorio italiano e globale in relazione anche ai flussi turistici nazionali ed intercontinentali. Per gli spazi indoor è stata invece valutata la relazione intercorrente tra sensazione termica e temperatura di colore della luce con l’obiettivo di ridurre i consumi energetici. La tesi è stata quindi suddivisa in cinque sezioni. Nella prima sono stati individuati, con riferimento all’area mediterranea, i valori della Physiological Equivalent Temperature (PET) neutrale e preferita, della temperatura dell’aria neutrale, del Physiological Equivalent Temperature (PET) comfort range ed è stato ricavato un nuovo indice empirico in grado di predire, sulla base dell’ASHRAE 7-point scale, la sensazione termica della popolazione mediterranea in ambienti aperti. Questo indice, denominato MOCI (Mediterranean Outdoor Comfort Index), predice però un voto medio ed è per tale ragione che è stata anche riadattata alla popolazione mediterranea la relazione della PPD (Predicted Percentage of Dissatisfied) proposta nell’ISO 7730. Le prestazioni del MOCI sono state poi confrontate numericamente con quelle di Actual Sensation Vote Europe (ASVEUROPE), Effective Temperature (ET), Physiological Equivalent Temperature (PET) e Predicted Mean Vote. È stato inoltre proposto e validato il Global Outdoor Comfort Index (GOCI), un indice empirico in grado di predire la percezione termica a livello globale. Nella seconda sezione sono state invece analizzate differenti strategie di mitigazione del microclima urbano. I siti analizzati sono il campus dell’Università degli Studi Sapienza di Roma, il chiostro di San Pietro in Vincoli (sede della Facoltà di Ingegneria del medesimo Ateneo) ed il canyon urbano di via delle Carrozze, anch’esso sito in Roma. Oltre ad un aumento dello urban greening, sono state implementate configurazioni caratterizzate dall’uso di materiali ad elevato coefficiente di albedo. L’analisi dei valori assunti dalle variabili micrometeorologiche e dagli indici di comfort termico è stata possibile grazie a modelli validati sperimentalmente ed elaborati attraverso il software ENVI-met. Per quest’ultimo, è stato inoltre proposto un nuovo approccio simulativo basato su dati provenienti da radiosondaggi. Nella terza sezione è stata valutata, con riferimento al territorio italiano e mondiale, la percezione termica di un individuo afferente all’area mediterranea (mediante il MOCI) e quella di un normotipo globale (mediante il PMV). I risultati, relazionati ai flussi turistici, sono stati elaborati in termini di andamenti orari annuali, valori medi settimanali e relativi picchi, diagrammi di frequenza, variazioni dei percentili e mappe spaziali. Nella quarta sezione, differentemente rispetto a quanto fatto in precedenza, vengono discussi aspetti legati al benessere termoigrometrico in ambiente interno. In particolare, si è cercato di valutare se la temperatura di colore della luce è in grado o meno di influenzare la percezione termica. Questo studio è stato effettuato in collaborazione con la “Escuela Técnica Superior de Ingeniería de Caminos, Canales y Puertos de la Universidad de Granada” e mira a ridurre i consumi energetici degli edifici. Per esempio, la temperatura di uno spazio confinato potrebbe essere inferiore in presenza di una luce con bassa temperatura di colore durante la stagione di riscaldamento e viceversa durante quella di raffrescamento. È stata quindi organizzata, all’interno di una test room, una field survey in cui sono state esaminate la percezione e preferenza termica, la tolleranza e l’accettabilità personale e la confortevolezza nello svolgere un dato compito in presenza di luce calda, neutrale e fredda. Nella quinta ed ultima sezione vengono infine riportati i risultati ottenuti

Parameters affecting the efficiency of a heat transformer with a particular focus on the heat solution

The heat transformer is a reverse cycle absorption machine, suitable for the direct exploitation of heat wastes and solar energy. Part of these wastes are “transformed” into thermal energy at a higher temperature than the one provided. Hence some studies concern the evaluation of the performances of the working fluids used. They must ensure a high level of efficiency which, as for the conventional absorption machines, depends on several parameters. One of these parameters is the heat solution: it is defined as the heat absorbed when a mole of a given component is mixed with the amount of the other component required to generate the desired solution at a certain temperature and pressure. This is the reason why the decision was to examine its influence with respect to machines exerting two different fluids which are generally used. The first one is NH3-H2O, whereas the second is H2O-LiBr; they used as refrigerating substances ammonia and water respectively and as absorption substances water and lithium bromide. Through an analytical modeling and the processing of experimental data provided by the bibliography, it was possible to show how, for these fluids, the terms of the sensible heat represent a moderate fraction of the global energy balance, at one condition though: highly efficient recovery exchangers must be present. Moreover there were reported values of the refrigeration effect of the order of thousands of kJ/kg with satisfying responses energetically speaking. Then a high stability of the fluid NH3-H2O was revealed, as testified by the high value of the difference between the concentration of the refrigerator in the absorber and the concentration of the refrigerator in the generato

Influence of input climatic data on simulations of annual energy needs of a building: energyplus and WRF modeling for a case study in Rome (Italy)

The simulation of the energy consumptions in an hourly regime is necessary in order to perform calculations on residential buildings of particular relevance for volume or for architectural features. In such cases, the simplified methodology provided by the regulations may be inadequate, and the use of software like EnergyPlus is needed. To obtain reliable results, usually, significant time is spent on the meticulous insertion of the geometrical inputs of the building, together with the properties of the envelope materials and systems. Less attention is paid to the climate database. The databases available on the EnergyPlus website refer to airports located in rural areas near major cities. If the building to be simulated is located in a metropolitan area, it may be affected by the local heat island, and the database used as input to the software should take this phenomenon into account. To this end, it is useful to use a meteorological model such as the Weather Research and Forecasting (WRF) model to construct an appropriate input climate file. A case study based on a building located in the city center of Rome (Italy) shows that, if the climatic forcing linked to the heat island is not considered, the estimated consumption due to the cooling is underestimated by 35–50%. In particular, the analysis and the seasonal comparison between the energy needs of the building simulated by EnergyPlus, with the climatic inputs related to two airports in the rural area of Rome and with the inputs provided by the WRF model related to the center of Rome, show discrepancies of about (i) WRF vs. Fiumicino (FCO): Δ = −3.48% for heating, Δ = 49.25% for cooling; (ii) WRF vs. Ciampino (CIA): Δ = −7.38% for heating, Δ = +35.52% for cooling

Decrease of the Maximum Speed in Highway Tunnels as a Measure to Foster Energy Savings and Sustainability

The high energy consumption of the lighting installations in highway tunnels has become a hot topic in the last few years due to the high figures in terms of money, consumed energy, use of raw materials, emissions of greenhouse gases due to the remarkable number of manufactured elements, and maintenance, among others. In spite of the different strategies proposed up to date and their savings, the potential benefits of decreasing the maximum speed allowed in tunnels have not been considered in depth as a complementary measure yet. In this work, the impact of such a decrease in terms of energy consumption, number projectors, carbon dioxide (CO2) emissions, and yearly costs in energy is analyzed and discussed. The results strongly suggest the convenience of introducing maximum speed reduction in traffic regulations which, in addition, could create positive synergies with traffic safety.This work was supported by the Spanish Ministry of Economy and Competitiveness as part of the Research Project ENE2015-67031-R (MINECO/FEDER)

On the impact of urban micro climate on the energy consumption of buildings

The energy consumption of urban buildings is affected by the surrounding microclimate which differs from standard weather data and by mutual obstructions between buildings, which decrease sunlight and wind potentials for internal solar gains and passive cooling. The building construction itself affects both outdoor and indoor microclimate. This research addresses these interdependences in respect with energy performance. An urban structures are investigated with a fixed value of H/W and solar orientation. The numerical method used is the building energy model (TRNSYS), for simulating building energetic and thermal responses to external and internal settings and the Sombrero software to evaluate the to evaluate the shading of surrounding buildings

Outdoor thermal comfort conditions during summer in a cold semi-arid climate. A transversal field survey in Central Anatolia (Turkey)

Abstract In the present study the outdoor thermal comfort conditions in Konya (Central Anatolia, Turkey) were examined during summer. This is why a transversal field survey was carried out and over 300 questionnaires were filled by randomly chosen participants. Moreover, environmental variables as air temperature, wind speed, relative humidity and globe temperature were constantly measured. This allowed to relate the thermal perception and preference votes given by the interviewees to the morphological and furniture characteristics of the surveyed sites. Then, taking into account at the same time all the obtained data, a regression line between the thermal perception votes and the corresponding PET (Physiological Equivalent Temperature) values was obtained and a neutral PET value of 26.8 °C was calculated. Based on a logistic curve model with the probit function, a preferred PET value of 19.2 °C was determined. On the other hand, the PET comfort range of (21.6)–(32.0) °C was obtained by considering, as thermal comfort interval, the range (−0.5)-(+0.5) of the ASHRAE 7-point scale. Finally, two outdoor thermal comfort indexes were introduced. The first one, called Turkish Outdoor Comfort Index (TOCI), is able to predict the thermal perception of the considered population in hot conditions. In the second case, the Predicted Percentage of Dissatisfied (PPD) relation was modified based on the surveyed data and outdoor sites

Repetitive Movements in Melon Cultivation Workers under Greenhouses

Musculoskeletal disorders cause serious problems that affect workers in many sectors. The objective of this study is the ergonomic analysis of melon cultivation farmers in Almeria-type greenhouses. For this, the rapid upper limb assessment (RULA) method has been applied after carrying out a detailed process of observing the farmers’ tasks. The study shows that 65% of the postures have a very-high-risk level, 26% high, 9% average, and no posture is found with a low risk. They also show that in 69.57% of the postures, the upper limbs are less affected than the others such as the neck, trunk, and lower limbs. Measures are proposed to improve the working conditions for workers

Conventional Industrial Robotics Applied to the Process of Tomato Grafting Using the Splicing Technique

Horticultural grafting is routinely performed manually, demanding a high degree of concentration and requiring operators to withstand extreme humidity and temperature conditions. This article presents the results derived from adapting the splicing technique for tomato grafting, characterized by the coordinated work of two conventional anthropomorphic industrial robots with the support of low-cost passive auxiliary units for the transportation, handling, and conditioning of the seedlings. This work provides a new approach to improve the efficiency of tomato grafting. Six test rates were analyzed, which allowed the system to be evaluated across 900 grafted units, with gradual increases in the speed of robots work, operating from 80 grafts/hour to over 300 grafts/hour. The results obtained show that a higher number of grafts per hour than the number manually performed by skilled workers could be reached easily, with success rates of approximately 90% for working speeds around 210–240 grafts/hour