Calibration of building energy simulation models based on optimization: A case study

This study applies an optimization-based approach for calibrating building energy models using monitored data. The calibration was carried out on a test building coupling the EnergyPlus energy simulation tool with the GenOpt optimization tool. The objective function was set to minimize the difference between simulated and monitored energy consumption. For evaluating the model accuracy, the Mean Bias Error (MBE) and the Coefficient of Variation of the \RMSE\ (Cv (RMSE)) were calculated and found consistent with \ASHRAE\ guideline 14 limits for a model to be considered calibrated

Dinamičke simulacije solarnih kombi-sustava sa sezonskim sorpcijskim spremnikom topline: Utjecaj konfiguracije kombi-sustava.

This paper focuses on the sizing of solar combisystems with adsorption seasonal storage to target autonomous solar space heating. Two main configurations of the combisystem are simulated, including one or two tanks. The influence of the seasonal storage on the sizing of the tanks is also discussed. The analysis is conducted in simulation using the TRNSYS program. Results show that performances of the system with two tanks are better (2 to 4 % with seasonal storage) but some improvements should be possible for the single tank configuration. The sizing of the sensible storage is nearly independent of the solar collector area if there is a seasonal storage. The sensible storage size increases with the collectors’ area without adsorption storage.Ovaj članak je fokusiran na dimenzioniranje solarnog kombi-sustava sa sezonskim adsorpcijskim spremnikom topline sa ciljem autonomnog solarnog grijanja prostora. Dvije konfiguracije kombi-sustava su simulirane, uključujući jedan ili dva toplinska spremnika. Utjecaj sezonskog skladištenja energije na dimenzioniranje spremnika je također diskutirano. Analiza je vršena simulacijom u programu TRNSYS. Rezultati analize pokazuju da je performansa sustava sa dva spremnika bolja (2 do 4% sa sezonskim skladištenjem), ali i neka poboljšanja su moguća za konfiguraciju sa jednim toplinski spremnikom. Dimenzioniranje spremnika osjetne topline je gotovo neovisno od površine solarnih kolektora ako postoji sezonski spremnik. U slučaju bez adsorpcijskog spremnika, veličina spremnika osjetne topline se povećava sa povećanjem površine kolektora

Green 4 Indoor - Wallonia Présentation AG SPHERES 18/12/2023

Présentation des résultats de recherche du projet G4i-W sur l'étude d'impacts en milieu intérieur des murs verts et sur la réutilisation des eaux grisesGreen 4 Indoor Walloni

mRNA-based approach to monitor recombinant gamma-interferon restoration of LPS-induced endotoxin tolerance

Introduction: It is now well accepted that sepsis is associated with the development of a pronounced immunosuppressive state, characterized by severe immune alterations (e.g. reduced proliferative capacity, endotoxin tolerance, apoptosis) participating in increased mortality and susceptibility to nosocomial infections. Efforts are currently aimed at restoring a functional immune response in septic patients. Successful therapydepends on the identification of appropriate immunostimulatory drugs and on the development of suitable biomarkers that could be used to stratify patients and to follow response to treatment.Methods: In this study, we evaluated the ex vivo effect of recombinant interferon gamma (rIFN-g) in restoring monocyte functionality (endotoxin-induced Tumor Necrosis Factor-a production) in a two-hit model of endotoxin tolerance (ET) with peripheral blood mononuclear cells from healthy volunteers and in whole blood of septic shockpatients. Importantly, we used quantitative-reverse transcription polymerase-chain reaction to monitor the effect of rIFN-g on the expression of seven genes known to participate in ET (TNF-a, IL-10, HLA-DRA, CIITA, IRAK-M, ABIN-3 and LY64).Results: Expression analysis of those genes confirmed the presence of an immunosuppression state and the ex vivo restoration of immune functions by rIFN-g. We show for the first time that rIFN-g is able to bypass, at the mRNA level, the effect of negative regulators of the LPS signalling pathway such as IRAK-M, ABIN-3 and LY64.Conclusions: Overall, mRNA expressions of a panel of genes could represent promising candidates for the ex vivo evaluation of rIFN-g effect on monocyte functionality. This ex vivo translational research study demonstrates the potential of a mRNA-based approach to successfully monitor drug efficacy

A randomized clinical trial indicates that levamisole increases the time to relapse in children with steroid-sensitive idiopathic nephrotic syndrome

Levamisole has been considered the least toxic and least expensive steroid-sparing drug for preventing relapses of steroid-sensitive idiopathic nephrotic syndrome (SSINS). However, evidence for this is limited as previous randomized clinical trials were found to have methodological limitations. Therefore, we conducted an international multicenter, placebo-controlled, double-blind, randomized clinical trial to reassess its usefulness in prevention of relapses in children with SSINS. The efficacy and safety of one year of levamisole treatment in children with SSINS and frequent relapses were evaluated. The primary analysis cohort consisted of 99 patients from 6 countries. Between 100 days and 12 months after the start of study medication, the time to relapse (primary endpoint) was significantly increased in the levamisole compared to the placebo group (hazard ratio 0.22 [95% confidence interval 0.11-0.43]). Significantly, after 12 months of treatment, six percent of placebo patients versus 26 percent of levamisole patients were still in remission. During this period, the most frequent serious adverse event (four of 50 patients) possibly related to levamisole was asymptomatic moderate neutropenia, which was reversible spontaneously or after treatment discontinuation. Thus, in children with SSINS and frequent relapses, levamisole prolonged the time to relapse and also prevented recurrence during one year of treatment compared to prednisone alone. However, regular blood controls are necessary for safety issues

Dynamic simulation of residential buildings with seasonal sorption storage of solar energy - parametric analysis

This work focuses on the evaluation of the performances of a solar combisystem coupled to seasonal thermochemical storage using SrBr2/H20 as adsorbent/adsorbate couple. The objective is to determine the characteristics required for solar system and storage reactor to reach a 100 % solar fraction for a building with a low heating load. The complete system, including the storage reactor, is simulated, using the dynamic simulation software TRNSYS. The influence of some components and parameters of the system is estimated: weather, collectors and storage reactor parameters.SOLAUTAR

Dynamic simulations of solar combisystems integrating a seasonal sorption storage: Influence of the combisystem configuration

peer reviewedThis paper focuses on the sizing of solar combisystems with adsorption seasonal storage to target autonomous solar space heating. Two main configurations of the combisystem are simulated, including one or two tanks. The influence of the seasonal storage on the sizing of the tanks is also discussed. Results show that performances of the system with two tanks are better (2 to 4 % with seasonal storage) but some improvements should be possible for the single tank configuration. The sizing of the sensible storage is nearly independent of the solar collectors area if there is a seasonal storage. The sensible storage size increase with the collectors area without adsorption storage. The analysis is conducted in simulation using the TRNSYS program.SOLAUTAR

Simulation of a vertical ground heat exchanger as low temperature heat source for a closed adsorption seasonal storage of solar heat

Get It @ ULg(opens in a new window)|View at Publisher| Export | Download | More... Energy Procedia Volume 48, 2014, Pages 370-379 2nd International Conference on Solar Heating and Cooling for Buildings and Industry, SHC 2013; Freiburg; Germany; 23 September 2013 through 25 September 2013; Code 104547 Simulation of a vertical ground heat exchanger as low temperature heat source for a closed adsorption seasonal storage of solar heat (Conference Paper) Hennaut, S.a , Thomas, S.a, Davin, E.a, Skrylnyk, A.b, Frère, M.b, André, P.a a University of Liège, Building Energy Monitoring and Simulation, Avenue de Longwy 185, 6700 Arlon, Belgium b University of Mons, Energy Research Cente, Boulevard Dolez 31, 7000 Mons, Belgium View references (9) Abstract This paper deals with the simulation of a vertical geothermal heat exchanger as low temperature heat source for a closed adsorption seasonal heat storage. The seasonal storage should allow reaching a nearly 100 % solar fraction for space heating of a "low energy" building". The selected adsorbent and adsorbate are respectively bromide strontium and water. The studied system, including the building and the ground exchanger, is simulated using the dynamic simulation software TRNSYS. Results show that expected performances are reached with a borehole of 100 m. The evaporation temperatures computed are really close to 0°C which might cause some problems. But an advanced research would maybe impose a deeper borehole to avoid cooling the ground on the long term.SOLAUTAR

Evaluation of micro combined heat and power systems in the Walloon residential sector through dynamic simulation

Combined Heat and Power (CHP) systems are known for a long time and are well established especially in the industrial sector where they allow interesting energy savings. However, the application of this technology in the residential and small tertiary sectors remains difficult due to the irregularity and the low heat demand during certain months of the year. The “Smart Micro Cogen” project focused on evaluating the potential of micro CHP systems (≤ 50kWe) in the Belgian building stock (residential and small tertiary sector) by means of dynamic simulation using TRNSYS 17 software. This work provides the hypotheses allowing representing the Belgian residential building stock and the different elements taken into account in the modelling and simulation of a complex HVAC system including a micro CHP system. Some results of the various simulations performed will be presented to show the robustness of the proposed modeling.Smart Micro Coge

About the use of CO2 as tracer gas for identification of air renewal; combination with co-heating test

peer reviewedThree types of tracer gas test are, until now, mentioned in international standards: Injection at constant indoor concentration, injection at constant flow rate and transient injection followed by a recording of the decontamination curve. A fourth method is proposed in this paper: it is based on the same scenario as the third method, but with weighting of the mass of tracer gas (CO2) injected and integration of the curve of indoor concentration on the whole testing period. The concentration peak is used to identify the “effective” volume of the building zone considered; this volume, associated to the final concentration, is used to calculate the amount of CO2 remaining inside the zone at the end of the test. The total mass of renovation air is then deduced from the corresponding CO2 mass balance. The CO2 can be injected from a bottle or directly produced by combustion on site. In the latter case, the tracer gas method is combined with a co-heating test. It can be done, for example, with a current camping butane cooker: From the weighting of this device and continuous recording of air temperature, CO2 concentration and humidity ratio, three significant (energy, CO2 and water) balances are established in such a way to verify and tune a reference simulation model of the building zone