A Study on the Application of Fan Curve Model in FDS for Modeling of Mechanical Ventilation System

Author(s):  
Ho-Sik Han ◽  
Cheol-Hong Hwang ◽  
Yong-Hun Jung ◽  
Sang-Kyu Lee
Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3008
Author(s):  
Agnieszka W. Lach ◽  
André V. Gaathaug

This paper presents a series of experiments on the effectiveness of existing mechanical ventilation systems during accidental hydrogen releases in confined spaces, such as underground garages. The purpose was to find the mass flow rate limit, hence the TPRD diameter limit, that will not require a change in the ventilation system. The experiments were performed in a 40 ft ISO container in Norway, and hydrogen gas was used in all experiments. The forced ventilation system was installed with a standard 315 mm diameter outlet. The ventilation parameters during the investigation were British Standard with 10 ACH and British Standard with 6 ACH. The hydrogen releases were obtained through 0.5 mm and 1 mm nozzles from different hydrogen reservoir pressures. Both types of mass flow, constant and blowdown, were included in the experimental matrix. The analysis of the hydrogen concentration of the created hydrogen cloud in the container shows the influence of the forced ventilation on hydrogen releases, together with TPRD diameter and reservoir pressure. The generated experimental data will be used to validate a CFD model in the next step.


2018 ◽  
Vol 196 ◽  
pp. 02007
Author(s):  
Arman Kostuganov ◽  
Yuri Vytchikov ◽  
Andrey Prilepskiy

The article describes development and application of self-contained ventilation systems in civil buildings. It suggests several models of air exchange within the building, compares these models and points out the variant of ventilating with self-contained mechanical systems with utilization of heat. The researchers conclude that structurally self-contained systems of mechanical ventilation with utilization of heat are most efficiently built into window constructions. This installation variant makes it possible to keep the interior, avoid building construction strengthening, shorten time and labor input of construction-assembling works, allow rational use of the vertical building envelopes area without extra space using. The paper key issue is the development of constructive solutions of self-contained ventilation systems main elements to ensure the possibility of their use in window structures. This research stage was developed with account of previous results of field tests and of such ventilation systems theoretical descriptions. The authors assess limit dimensions of the systems suitable for installment into window constructions of civil buildings in the view of modern Russian requirements to thermal protection. The research suggests a general constructive solution of such a ventilation system and a heat exchanger model which can be used as an air heat utilizer in these systems.


Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Liming Hao ◽  
Shuai Ren ◽  
Yan Shi ◽  
Na Wang ◽  
Yixuan Wang ◽  
...  

The synchrony of patient-ventilator interaction affects the process of mechanical ventilation which is clinically applied for respiratory support. The occurrence of patient-ventilator asynchrony (PVA) not only increases the risk of ventilator complications but also affects the comfort of patients. To solve the problem of uncertain patient-ventilator interaction in the mechanical ventilation system, a novel method to evaluate patient-ventilator synchrony is proposed in this article. Firstly, a pneumatic model is established to simulate the mechanical ventilation system, which is verified to be accurate by the experiments. Then, the PVA phenomena are classified and detected based on the analysis of the ventilator waveforms. On this basis, a novel synchrony index SIhao is established to evaluate the patient-ventilator synchrony. It not only solves the defects of previous evaluation indexes but also can be used as the response parameter in the future research of ventilator control algorithms. The accurate evaluation of patient-ventilator synchrony can be applied to the adjustment of clinical strategies and the pathological analyses of patients. This research can also reduce the burden on clinicians and help to realize the adaptive control of the mechanical ventilation and weaning process in the future.


Author(s):  
A I Sharapov ◽  
E Y Myakotina ◽  
Y V Shatskikh ◽  
A V Peshkova

2019 ◽  
Vol 27 (03) ◽  
pp. 1950027
Author(s):  
Young Kwon Yang ◽  
Min Young Kim ◽  
Jin Woo Moon ◽  
Jin Chul Park

Ventilation in buildings is the simplest and most convenient way to purify indoor air. However, when the ventilation is not enough due to natural ventilation, it should be cleaned by mechanical ventilation or air purifier. This process requires building energy. Therefore, it is possible to save the energy of the building by merely increasing the natural ventilation efficiency. This study conducted airflow analysis simulations to investigate the effects of changes in the shape of ventilation openings and louvers on the ventilation efficiency of a window ventilation system. The streamlined window opening exhibited a greater increase in airflow (41.3%) than did the conventional window (24.3%) for the ventilation model with four openings. It was also observed that flow separation and wakes were generated by the adverse pressure gradient arising from the increased airflow speed when a louver was employed. Based on these results, it can be concluded that using a louver as a wind augmentation device is an obstacle to improving the airflow in a window ventilation system.


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