Introducing Solar Thermal "Net Metering" in an Actual small-scale District Heating System: A Case-study Analysis☆

Abstract An energy and economic analysis on an hypothesis of introduction of prosumers in an actual small-scale district heating system (DHS) in Northern Italy has been carried out. The study was performed by means of dynamic simulations of the DHS. The investigated configurations include the transformation of one or more customers in prosumers, producing and self-consuming solar thermal heat, and supplying the DHS with the excess heat produced. For the considered case-study the solar heat fed into the DHS is basically antagonist of the CHP production. This leads to a decrease in the non-renewable energy share for the whole DHS, to a decrease in the profit of the DHS utility and to a profitable investment for the prosumers

A novel measurement method for accurate heat accounting in historical buildings

Nowadays, two different heat accounting methods are available: the direct method, based on heat meters, and the indirect one, based on heat cost allocators. Unfortunately, in existing buildings, due to the plant configuration, heat meters are often technically unfeasible or not cost efficient, whereas heat cost allocators can be easily installed in almost all conditions. At the same time, the indirect method relies on a high number of interconnected devices with installation and operative conditions often variable within the same building and influencing the on-field metrological performances. In this paper, the authors propose a novel "hybrid" method for accurate heat accounting combining the advantages of indirect method with the higher accuracy typical of direct methods. The proposed method has been experimented at INRIM, the primary metrology institute in Italy, assessing the on-field performance in a virtual eight-apartments building. The experimental results show that the proposed method always presents improved accuracy. (C) 2020 Elsevier Ltd. All rights reserved

Alternative energy storage options for heat pump water heater coupled with photovoltaic plant for domestic hot water production

The present work relies on the topic of energy storage for Heat and Electricity applied to Heat Pump Water Heaters coupled with photovoltaic plants for Domestic Hot Water production. The main idea is to evaluate the possibility to exploit the water tank as heat storage for the produced photovoltaic energy and, where appropriate combined with electrical storage. For this reason, two heat pumps with different volume size have been chosen and smart control strategies have been applied while monitoring the water temperature in the tank. Calculations account on tapping profile inferred from monitored data of a representative end-user in a Mediterranean small island. Results show how the combination of smart control strategies and battery systems is the most suitable solution in order to fulfil the domestic hot water energy demand by renewable sources while maintaining comfort requirements

Utilities Substations in Smart District Heating Networks

Abstract In the last decades the concept of distributed generation – i.e. the installation of (electrical and/or thermal) energy production systems at the final users – was born and found gradually increasing diffusion. For what concerns the electrical production, the distributed generation systems are directly connected to the National Electricity Transmission Grid, allowing a bidirectional energy flux at the utilities and giving rise to the so-called smart grid. In this scenario and considering that, even thanks to the direction taken by European regulations, in the European territory there is already a large number of thermal power generation's distributed systems (e.g. solar thermal panels), in the near future the concept of smart grid could be extended to the heat sector, especially in relation to District Heating Networks (DHNs). As a consequence, with the aim of analyzing the penetration of this type of networks, several possible layouts for the exchange utilities' substation have been developed and will be presented in this study. Such layouts allow to optimize thermal exchange, as a function of network design temperatures (for both the supply and the return), of utilities' thermal power requirement and depending on the characteristics of the production system

Ageing test of the ATLAS RPCs at X5-GIF

An ageing test of three ATLAS production RPC stations is in course at X5-GIF, the CERN irradiation facility. The chamber efficiencies are monitored using cosmic rays triggered by a scintillator hodoscope. Higher statistics measurements are made when the X5 muon beam is available. We report here the measurements of the efficiency versus operating voltage at different source intensities, up to a maximum counting rate of about 700Hz/cm^2. We describe the performance of the chambers during the test up to an overall ageing of 4 ATLAS equivalent years corresponding to an integrated charge of 0.12C/cm^2, including a safety factor of 5.Comment: 4 pages. Presented at the VII Workshop on Resistive Plate Chambers and Related Detectors; Clermont-Ferrand October 20th-22nd, 200

System Test of the ATLAS Muon Spectrometer in the H8 Beam at the CERN SPS

An extensive system test of the ATLAS muon spectrometer has been performed in the H8 beam line at the CERN SPS during the last four years. This spectrometer will use pressurized Monitored Drift Tube (MDT) chambers and Cathode Strip Chambers (CSC) for precision tracking, Resistive Plate Chambers (RPCs) for triggering in the barrel and Thin Gap Chambers (TGCs) for triggering in the end-cap region. The test set-up emulates one projective tower of the barrel (six MDT chambers and six RPCs) and one end-cap octant (six MDT chambers, A CSC and three TGCs). The barrel and end-cap stands have also been equipped with optical alignment systems, aiming at a relative positioning of the precision chambers in each tower to 30-40 micrometers. In addition to the performance of the detectors and the alignment scheme, many other systems aspects of the ATLAS muon spectrometer have been tested and validated with this setup, such as the mechanical detector integration and installation, the detector control system, the data acquisition, high level trigger software and off-line event reconstruction. Measurements with muon energies ranging from 20 to 300 GeV have allowed measuring the trigger and tracking performance of this set-up, in a configuration very similar to the final spectrometer. A special bunched muon beam with 25 ns bunch spacing, emulating the LHC bunch structure, has been used to study the timing resolution and bunch identification performance of the trigger chambers. The ATLAS first-level trigger chain has been operated with muon trigger signals for the first time

Measurement of χ c1 and χ c2 production with s√ = 7 TeV pp collisions at ATLAS

The prompt and non-prompt production cross-sections for the χ c1 and χ c2 charmonium states are measured in pp collisions at s√ = 7 TeV with the ATLAS detector at the LHC using 4.5 fb−1 of integrated luminosity. The χ c states are reconstructed through the radiative decay χ c → J/ψγ (with J/ψ → μ + μ −) where photons are reconstructed from γ → e + e − conversions. The production rate of the χ c2 state relative to the χ c1 state is measured for prompt and non-prompt χ c as a function of J/ψ transverse momentum. The prompt χ c cross-sections are combined with existing measurements of prompt J/ψ production to derive the fraction of prompt J/ψ produced in feed-down from χ c decays. The fractions of χ c1 and χ c2 produced in b-hadron decays are also measured

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Study of Z Boson Pair Production in e+e- Collisions at LEP at \sqrt{s}=189 GeV

The pair production of Z bosons is studied using the data collected by the L3 detector at LEP in 1998 in e+e- collisions at a centre-of-mass energy of 189 GeV. All the visible final states are considered and the cross section of this process is measured to be 0.74 +0.15 -0.14 (stat.) +/- 0.04 (syst.) pb. Final states containing b quarks are enhanced by a dedicated selection and their production cross section is found to be 0.18 +0.09 -0.07 (stat.) +/- 0.02 (syst.) pb. Both results are in agreement with the Standard Model predictions. Limits on anomalous couplings between neutral gauge bosons are derived from these measurements