Search results for "DEMAND"
showing 10 items of 759 documents
Ventilation rates and unsatisfied percentage from indoor CO2 concentration.
2011
This work reports the results of a survey carried out on a hall in a historic building in Palermo (Italy) with the aim of assessing the air quality by means of objective measurement of carbon dioxide (CO2) concentration and its subjective evaluation through a questionnaire. The measured values of CO2 concentration were compared with those evaluated using the Meckler equation under steady-state conditions, having verified necessary parameters such as the constancy of the indoor and outdoor CO2 levels and the uniformity of the CO2 generation rate for all the occupants. The positive correspondence between measured and calculated results allowed us to utilise, under differing circum- stances, t…
Thermal and structural properties of a hemp–lime biocomposite
2013
Abstract The need to reduce greenhouse gases emission produced by the building sector leads to the research of renewable and less impacting materials that can replace traditional ones. This subject has encouraged new researches on biocomposite concretes with the aim to exploit renewable resources like vegetal fibres intended as materials whose production processes are generally characterized by low costs and energy demand. This biocomposite is obviously much lighter than concrete and, therefore, can be suitably used in such cases where a structure cannot be overloaded, for instance in the realization of a green covering on top of a preexistent building. In this work, a first analysis of the…
Numerical assessment of heating energy demand for office buildings in Italy
2016
Buildings energy consumption depends on several parameters, such as climate, envelope typologies, occupant behavior, intended use, etc.; assessment of the energy performance of a building requires substantial input data describing constructions, environmental contexts, thermo-physical properties, geometry, control strategies and several other parameters influencing the thermal balance. In the last years, several numerical approaches dedicated to building simulation have been tested developing specialized software. On the other hand, simplified building models permit the evaluation of indoor conditions and heating/cooling loads with a good level of accuracy and without excessive computationa…
A Method for Analysing Heating Demand and Energy Saving Actions for Regional Residential Building Stocks
2013
In this paper a method is described, originally conceived during the compilation of the Energy and Environmental Regional Plan of Sicily, aimed to: a) set up a lay-out model of an overall regional residential estate into a certain number of different building and heating system types; b) calculate the energy needs of every single type according to the procedures established by the national and European regulations; The method is particularly designed to evaluate the possible energy savings from the implementation of different interventions concerning the envelope and the HVAC systems to the various building types. The method, although based on several assumptions, shows to be reliable enoug…
A bottom-up method for evaluating the whole energy demand of large residential building stocks: an application to a regional scale
2013
In this paper a method is described, originally conceived during the compilation of the Energy and Environmental Regional Plan of Sicily, aimed to: a) set up a lay-out model of an overall regional residential estate into a certain number of different building and heating system types; b) calculate the energy needs of every single type according to the procedures established by the national and European regulations; The method is particularly designed to evaluate the possible energy savings from the implementation of different interventions concerning the envelope and the HVAC systems to the various building types. The method, although based on several assumptions, shows to be reliable enoug…
Towards Positive Energy Districts: Energy Renovation of a Mediterranean District and Activation of Energy Flexibility
2023
The paper presents the analysis of energy retrofitting, integration of renewable energy and activation of energy flexibility in a cluster of buildings in the surroundings of a port on the Mediterranean Sea in Southern Italy, with the aim of checking the potential for it to achieve the status of positive energy district (PED). The objective of this study is to improve the contemporaneity between local energy generation and energy demand and reduce CO2eq emissions by considering signals that reflect the environmental variability of the electricity grid, through flexibility solutions applied to the HVAC system. The proposed scenarios are based on the dynamic simulation of the district and anal…
Techno-economic analysis of integrated processes for the treatment and valorisation of neutral coal mine effluents
2020
Abstract The disposal of highly-concentrated neutral coal mine effluents into the environment constitutes a severe threat to the natural ecosystem. This work proposes and compares five novel treatment chains to purify the effluent and recover raw materials. The chains present different combinations of pre-treatment and concentration technologies. In all cases, the solution sent to the concentration step is concentrated up to saturation to recover water and sodium chloride. Concerning the technical performances, the treatment chains are compared in terms of total energy demand and salt recovery. Furthermore, the economic feasibility assessment is performed via a novel global parameter, i.e. …
The acid–base flow battery : Sustainable energy storage via reversible water dissociation with bipolar membranes
2020
The increasing share of renewables in electric grids nowadays causes a growing daily and seasonal mismatch between electricity generation and demand. In this regard, novel energy storage systems need to be developed, to allow large-scale storage of the excess electricity during low-demand time, and its distribution during peak demand time. Acid–base flow battery (ABFB) is a novel and environmentally friendly technology based on the reversible water dissociation by bipolar membranes, and it stores electricity in the form of chemical energy in acid and base solutions. The technology has already been demonstrated at the laboratory scale, and the experimental testing of the first 1 kW pilot pla…
Power Consumption in Uncovered Unbaffled Stirred Tanks: Influence of the Viscosity and Flow Regime
2013
Notwithstanding the increasing industrial interest toward unbaffled tanks, available experimental information on their behavior is still scant, even for basic quantities such as the mechanical power drawn. In this work, the influence of the Reynolds and Froude numbers on the power consumption characteristics is presented for unbaffled stirred tanks operating both in nonaerated conditions (subcritical regime) and in aerated conditions (supercritical regime), i.e., when the free surface vortex has reached the impeller and the gas phase is ingested and dispersed inside the reactor. Experimental results obtained at various liquid viscosities show that power numbers obtained in subcritical condi…