OPTIMUM DESIGN OF FORCED VENTILATION SYSTEM OF PIGLET HOUSE USING COMPUTER SIMULATION

2002 ◽  
Author(s):  
I. Lee ◽  
W. Park ◽  
B. Yu ◽  
J. Yun ◽  
J. Chun ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Optimum Design ◽  
Ventilation System ◽  
Forced Ventilation

scholarly journals Effect of Mechanical Ventilation on Accidental Hydrogen Releases—Large-Scale Experiments

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3008
Author(s):  
Agnieszka W. Lach ◽  
André V. Gaathaug
Keyword(s):  
Mechanical Ventilation ◽  
Mass Flow ◽  
Large Scale ◽  
Ventilation System ◽  
Hydrogen Gas ◽  
Forced Ventilation ◽  
British Standard ◽  
Confined Spaces ◽  
Series Of Experiments ◽  
Rate Limit

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.

scholarly journals Optimizing air velocity for the underfloor forced ventilation to protect a refrigerated warehouse from frost heaving

2018 ◽  
Vol 38 (3) ◽  
pp. 321-327
Author(s):  
Jingfu Jia ◽  
Manjin Hao ◽  
Jianhua Zhao
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Frost Heave ◽  
Forced Ventilation ◽  
Air Velocity ◽  
Set Up

Forced or natural ventilation is the most common measure of frost heave protection for refrigerated warehouse floor. To optimize air velocity for the underfloor forced ventilation system of refrigerated warehouse, a steady state three-dimensional mathematical model of heat transfer is set up in this paper. The temperature fields of this system are simulated and calculated by CFD software PHOENICS under different air velocity, 1.5m/s, 2.5m/s or 3.5m/s. The results show that the optimized air velocity is 1.5m/s when the tube spacing is 1.5m.

scholarly journals The use of frozen semen to minimize inbreeding in small populations

2002 ◽  
Vol 80 (1) ◽  
pp. 27-30 ◽  
Author(s):  
ANNA K. SONESSON ◽  
MIKE E. GODDARD ◽  
THEO H. E. MEUWISSEN
Keyword(s):  
Computer Simulation ◽  
Optimum Design ◽  
Simulation Study ◽  
Genetic Conservation ◽  
Gene Bank ◽  
Small Populations ◽  
Computer Simulation Study ◽  
Simple Scheme ◽  
Alternative Scheme ◽  
Frozen Semen

In this study, we compared the average coancestry and inbreeding levels for two genetic conservation schemes in which frozen semen from a gene bank is used to reduce the inbreeding in a live population. For a simple scheme in which only semen of generation-0 (G0) sires is used, the level of inbreeding asymptotes to 1/(2N), where N is the number of newborn sires in the base generation and rate of inbreeding goes to zero. However, when only sires of G0 are selected, all genes will eventually descend from the founder sires and all genes from the founder dams are lost. We propose an alternative scheme in which N sires from generation 1 (G1), as well as the N sires from G0, have semen conserved, and the semen of G0 and G1 sires is used for dams of odd and even generation numbers, respectively. With this scheme, the level of inbreeding asymptotes to 1/(3N) and the genes of founder dams are also conserved, because 50% of the genes of sires of G1 are derived from the founder dams. A computer simulation study shows that this is the optimum design to minimize inbreeding, even if semen from later generations is available.

scholarly journals A Forced Ventilation Micropropagation System for Photoautotrophic Production of Sweetpotato Plug Plantlets in a Scaled-up Culture Vessel: I. Growth and Uniformity

2001 ◽  
Vol 11 (1) ◽  
pp. 90-94 ◽  
Author(s):  
Jeongwook Heo ◽  
Sandra B. Wilson ◽  
Toyoki Kozai
Keyword(s):  
Ipomoea Batatas ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Photon Flux ◽  
Air Distribution ◽  
Culture Vessel ◽  
Forced Ventilation ◽  
Photoautotrophic Growth ◽  
Plantlet Growth ◽  
Ventilation Rates

An improved forced ventilation micropropagation system was designed with air distribution pipes for uniform spatial distributions of carbon dioxide (CO2) concentration and other environmental factors to enhance photoautotrophic growth and uniformity of plug plantlets. Single-node stem cuttings of sweetpotato [Ipomoea batatas (L.) Lam. `Beniazuma'] were photoautotrophically (no sugar in the culture medium) cultured on a mixture of vermiculite and cellulose fibers with half-strength Murashige and Skoog basal salts in a scaled-up culture vessel with an inside volume of 11 L (2.9 gal). CO2 concentration of the supplied air and photosynthetic photon flux on the culture shelf were maintained at 1500 μmol·mol-1 and 150 μmol·m-2·s-1, respectively. Plantlets grown in forced ventilation systems were compared to plantlets grown in standard (natural ventilation rate) tissue culture vessels. The forced (F) ventilation treatments were designated high (FH), medium (FM), and low (FL), and corresponded to ventilation rates of 23 mL·s-1 (1.40 inch3/s), 17 mL·s-1 (1.04 inch3/s), and 10 mL·s-1 (0.61 inch3/s), respectively, on day 12. The natural (N) ventilation treatment was extremely low (NE) at 0.4 mL·s-1 (0.02 inch3/s), relative to the forced ventilation treatments. On day 12, the photoautotrophic growth of plantlets was nearly two times greater with the forced ventilation system than with the natural ventilation system. Plantlet growth did not significantly differ among the forced ventilation rates tested. The uniformity of the plantlet growth in the scaled-up culture vessel was enhanced by use of air distribution pipes that decreased the difference in CO2 concentration between the air inlets and the air outlet.

Optimum Design of Laminated Corrugated Metal Gasket Using Computer Simulation

2019 ◽  
Vol 11 (5) ◽  
Author(s):  
Shigeyuki Haruyama ◽  
◽  
Moch. Agus Choiron ◽  
Didik Nurhadiyanto ◽  
◽  
...  
Keyword(s):  
Computer Simulation ◽  
Optimum Design ◽  
Corrugated Metal

The Optimum Design of Engine Cooling System by Computer Simulation

1994 ◽  
Author(s):  
Tetsuya Sakai ◽  
Shinichi Ishiguro ◽  
Yoshifusa Sudoh ◽  
Gottfried Raab ◽  
Josef Hager
Keyword(s):  
Computer Simulation ◽  
Optimum Design ◽  
Cooling System ◽  
Engine Cooling

scholarly journals Gas analysis devices for controlling the ventilation system in the house

2018 ◽  
pp. 31-35
Author(s):  
V. Kozubovskyy ◽  
I. Aljakshev
Keyword(s):  
Gas Sensors ◽  
Electrochemical Sensors ◽  
Ventilation System ◽  
Gas Analysis ◽  
Living Room ◽  
Forced Ventilation ◽  
Proportional Control ◽  
Autonomous Mode ◽  
Point Control ◽  
And Control

Now in modern houses for the purpose of energy saving use the airtight doors and windows. This causes the need for forced ventilation of the spaces. Usually use a mechanical ventilation system controlled by gas sensors. Gas sensors control the permissible concentration of certain gas components in the living room and on/off, if necessary, a ventilation system. Depending on the type of living spaces used point control, proportional control, or control of the rate of growth of concentration. We have developed gas analyzers of oxygen, СО2  , СО to control the concentration of these gases in the living rooms and control the forced ventilation. Electrochemical sensors of these gases were used as inexpensive, selective and non-consuming electricity. The devices developed on their basis have insignificant weight, dimensions and can work in the autonomous mode with the power from the battery.

scholarly journals A Forced Ventilation Micropropagation System for Photoautotrophic Production of Sweetpotato Plug Plantlets in a Scaled-up Culture Vessel: II. Carbohydrate Status

2001 ◽  
Vol 11 (1) ◽  
pp. 95-99 ◽  
Author(s):  
Sandra B. Wilson ◽  
Jeongwook Heo ◽  
Chieri Kubota ◽  
Toyoki Kozai
Keyword(s):  
Ipomoea Batatas ◽  
Starch Content ◽  
Soluble Sugar ◽  
Ventilation System ◽  
Soluble Sugars ◽  
Leaf Tissue ◽  
Photon Flux ◽  
Culture Vessel ◽  
Forced Ventilation ◽  
Starch Concentration

Sweetpotato [Ipomoea batatas (L.) Lam., `Beniazuma'] plantlets were grown photoautotrophically (without sugar) for 12 days in an improved forced ventilation system designed with air distribution pipes for uniform spatial distributions of carbon dioxide (CO2) concentration. Enriched CO2 conditions and photosynthetic photon flux (PPF) were provided at 1500 μmol·mol-1 and 150 μmol·m-2·s-1, respectively. The forced (F) ventilation treatments were designated high (FH), medium (FM), and low (FL), corresponding to ventilation rates of 23 mL·s-1 (1.40 inch3/s), 17 mL·s-1 (1.04 inch3/s), and 10 mL·s-1 (0.61 inch3/s), respectively, on day 12. The natural (N) ventilation treatment was extremely low (NE) at 0.4 mL·s-1 (0.02 inch3/s), relative to the forced ventilation treatments. Total soluble sugar (TSS) and starch content were determined on day 12. Total soluble sugars (sucrose, glucose, fructose) of FH plantlets were lowest in leaf tissue and highest in stem tissue as compared to other ventilation treatments. Starch concentration was higher in leaf tissue of FH or FM plantlets as compared to that of FL or NE plantlets. Plantlets subjected to FH or FM treatments exhibited significantly higher net photosynthetic rates (NPR) than those of the other treatments; and on day 12, NPR was almost five times higher in the FH or FM treatment than the FL or NE treatments. Carbohydrate concentration of plantlets was also influenced by the position of the plantlets in the vessel. Within the forced ventilation vessels, leaf TSS of FH and FM plantlets was similar regardless of whether plantlets were located near the inlet or outlet of CO2 enriched air. However, under FH or FM conditions, leaf starch concentration was higher in plantlets located closest to the CO2 inlet as compared to the outlet.

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