scholarly journals Variation of air flow distribution in the room with air jet angle, air flow rate and inlet air temperature from the outlet of air conditioner

1987 ◽  
Vol 7 (Supplement) ◽  
pp. 101-104
Author(s):  
Kunihiko MIYAKE ◽  
Kanjiro KINOSHITA ◽  
Kunikazu TORIKOSHI
Keyword(s):  
Air Temperature ◽  
Flow Rate ◽  
Air Flow ◽  
Flow Distribution ◽  
Air Conditioner ◽  
Air Flow Rate ◽  
Air Jet

Optimization of Drying Kinetics and Quality Parameters of Broccoli Florets

2011 ◽  
Vol 7 (2) ◽  
Author(s):  
Andrea V Mahn ◽  
Paola Antoine ◽  
Alejandro Reyes
Keyword(s):  
Antioxidant Activity ◽  
Air Temperature ◽  
Flow Rate ◽  
Air Flow ◽  
Radical Scavenging ◽  
Particle Diameter ◽  
Drying Kinetics ◽  
Convective Drying ◽  
Air Flow Rate ◽  
Drying Time

Drying kinetics of broccoli florets in a tunnel dryer was studied. Effective moisture diffusivity (Deff) and activation energy for moisture diffusion (E0) were estimated. The effect of air temperature, air flow rate and particle size on antioxidant capacity, greenness and texture were calculated through a 23 factorial design. Air flow rate and temperature significantly affected drying time. Deff fluctuated between 2.82 x 10-10 and 2.00 x 10-9 (m2/s), and E0 was around 42 KJ/mol, agreeing with values reported in literature. The maximum antioxidant activity was obtained at 60°C, air flow rate of 4 m/s and 1.5 cm particle diameter, resulting in a 70 percent reduction in free radical scavenging ability and a 29 percent increase in total reductive capability. Air temperature had significant effect on greenness, and air flow rate significantly affected texture. The optimization of convective drying of broccoli allows maximizing antioxidant activity and minimizing cost by saving energy and time.

Water Flow Distribution in Horizontal Protruding-Type Header Contaminated With Bubbles

1999 ◽  
Author(s):  
Sachiyo Horiki ◽  
Masahiro Osakabe
Keyword(s):  
Uniform Distribution ◽  
Gas Phase ◽  
Water Flow ◽  
Flow Rate ◽  
Water Distribution ◽  
Air Flow ◽  
Water Flow Rate ◽  
Flow Distribution ◽  
Air Flow Rate ◽  
Distribution Behavior

Abstract Flow header for small multiple pipes is commonly used in boilers and heat exchangers. The system contributes to raise the heat transfer efficiency in the components. The flow distribution mechanism of the header for water has been studied and the calculation procedure for the design has been recommended for a single-phase condition. It is also recommended to avoid the bubbles in the header to obtain a uniform water flow rate to each small pipe. But in some cases, the header has to be used to distribute a flow containing bubbles. Distribution behavior of water with a gas-phase was studied experimentally in a horizontal header with four vertical pipes. In the present experimental header, it was possible to protrude the branch pipes inside of the header and the effect of protruding length on the water distribution behavior was studied. When the protruding length was 0, the water distribution rate to the first pipe rapidly increased and the rates to the others decreased with a small amount of bubbles. As the bubbles in the header were absorbed only into the first pipe, the average two-phase density in the first pipe decreased. The decreased pressure head promotes the rush of water into the first pipe such as in an airlift pump. By increasing the air flow rate in the header inlet further, the flow rate to the first pipe took a maximum and then tended to decrease. The increased air flow rate in the first pipe increased the pressure loss in the pipe and resulted in a reduction in the water flow rate. The more important and serious behavior could be seen in the other pipes where the water flow rate decreased to 1/5 of the uniform distribution rate. By increasing the protruding length, the non-uniform distribution of water was suppressed because the gas-phase entered not only the first pipe but also the others. The best result was obtained when the four branch pipes were protruded into the center of header.

Effects of air temperature and air flow rate control on the tipburn occurrence of leaf lettuce in a closed-type plant factory system

2013 ◽  
Vol 54 (4) ◽  
pp. 303-310 ◽  
Author(s):  
Jun Gu Lee ◽  
Chang Sun Choi ◽  
Yoon Ah Jang ◽  
Suk Woo Jang ◽  
Sang Gyu Lee ◽  
...  
Keyword(s):  
Air Temperature ◽  
Flow Rate ◽  
Rate Control ◽  
Air Flow ◽  
Air Flow Rate ◽  
Closed Type ◽  
Plant Factory ◽  
Flow Rate Control ◽  
Leaf Lettuce

Effect of Process Parameters on Characteristics of Spray-Dried Hydroxyapatite Granules

2017 ◽  
Vol 728 ◽  
pp. 341-346 ◽  
Author(s):  
Weeranuch Sukaraseranee ◽  
Sukasem Watcharamaisakul ◽  
Boris Golman ◽  
Jintamai Suwanprateeb
Keyword(s):  
Size Distribution ◽  
Air Temperature ◽  
Flow Rate ◽  
Feed Rate ◽  
Air Flow ◽  
Spherical Shape ◽  
Air Flow Rate ◽  
Uniform Size ◽  
Drying Conditions ◽  
Spray Dried

The effects of drying air temperature and flow rate, spraying air flow rate and slurry feed rate were investigated on the morphology, size distribution, density and flowability of spray-dried hydroxyapatite granules. The granules were of good spherical shape and smooth surface, but low flowability. The granules of uniform size distribution were obtained at high spraying air flow rate and granules of small sizes were collected at high spraying and drying air flow rates, high slurry feed rate and low drying air temperature. Thus, by adjusting the spray drying conditions we can control the granule properties.

Experimental Study of Solar Air Heating System Based on Unglazed Transpired Collector

2011 ◽  
Author(s):  
Lixin Gao ◽  
Hua Bai ◽  
Xiumu Fang
Keyword(s):  
Surface Temperature ◽  
Air Temperature ◽  
Flow Rate ◽  
Temperature Rise ◽  
Air Flow ◽  
Heating System ◽  
Airflow Rate ◽  
Air Flow Rate ◽  
Air Heating ◽  
Collector Efficiency

An experimental rig was set up to test the thermal performance of a solar air heating system based on an unglazed transpired collector of 2.5 m2. The experiment was carried out at Harbin Institute of Technology in the city of Harbin, which is located in northeastern China, at latitude 45°41′ N and longitude 126°37′ E. The tests were spread over a number of days, in which the 4-day experimental data within the period were selected as the sample for analysis. Experimental results show that solar collector’s surface temperature and exit air temperature increase with increasing solar irradiation. The influence of ambient temperature on surface temperature and exit temperature is negligible. Temperature rise decreases with increasing air flow rate, while collector efficiency increases with increasing air flow rate. For an air flow rate of 100 m3/h in Test 1, the average air temperature rise and collector efficiency were 28.86°C and 72% respectively; for an air flow rate of 235 m3/h in Test 2, the average air temperature rise and collector efficiency were 11.52°C and 78% respectively. Higher airflow rate tends to operate the collector at lower surface temperature, which results in lower overall heat losses from the collector to the surroundings, therefore increasing airflow rate reduces air temperature rise and enhances the collector efficiency. The average efficiency of the experimental solar air heating system in the 4-day experiment period was 72%, 78%, 61%, and 72% respectively, which are higher than most conventional glazed flat-plate solar air collectors. With better coordination with architectural design at early stage in a project, this building-integrated solar air heating system can be both aesthetically and technically viable.

Numerical Modeling of Perforated Tile Flow Distribution in a Raised-Floor Data Center

2007 ◽  
Author(s):  
Emad Samadiani ◽  
Jeffrey Rambo ◽  
Yogendra Joshi
Keyword(s):  
Numerical Modeling ◽  
Flow Rate ◽  
Data Center ◽  
Air Conditioning ◽  
Air Flow ◽  
Flow Distribution ◽  
Air Flow Rate ◽  
Tile Flow ◽  
Operating Points

This paper is centered on quantifying the effect of computer room and computer room air conditioning (CRAC) unit modeling on the perforated tile flow distribution in a representative raised-floor data center. Also, this study quantifies the effect of plenum pipes and perforated tile porosity on the operating points of the CRAC blowers, total CRAC air flow rate, and its distribution. It is concluded that modeling the computer room, CRAC units, and/or the plenum pipes could change the tile flow distribution by up to 60% for the facility with 25% open perforated tiles and up to 135% for the facility with 56% open perforated tiles.

scholarly journals Choosing a Universal Air Collector Design for a Cylindrical-Shaped Hot-Wire Anemometer

2021 ◽  
Vol 24 (2) ◽  
pp. 6-15
Author(s):  
Oleh S. Tsakanian ◽  
◽  
Serhii V. Koshel ◽  
Keyword(s):  
Flow Rate ◽  
Measurement Errors ◽  
Air Flow ◽  
Aerodynamic Resistance ◽  
Experimental Studies ◽  
Flow Distribution ◽  
Hot Wire ◽  
Air Flow Rate ◽  
Measuring Device ◽  
Calibration Dependence

Air flow measurement at the outlets of air terminal devices installed in ventilation systems is very difficult. At the outlets of anemostats, swirl diffusers, grilles, the air flow can swirl, contract, or expand sharply, change its direction, etc., which causes great measurement errors. Therefore, it was necessary to develop a universal measuring device that would make it possible to measure air flow rate with high accuracy. It should consist of an air collector (for collecting and rectifying air flow) and a sensor for measuring air flow rate (integral hot-wire anemometer). Several air collector designs have been investigated. The parabolic air collector was chosen as the rational one. It has low aerodynamic resistance and good air flow distribution. To reduce the influence of turbulence and air swirling, a cylindrical stilling channel with a built-in rectifying grille is connected to the air collector. Experimental studies on various air distribution devices made it possible to obtain a refined calibration dependence for an integral hot-wire anemometer, the dependence being used to calculate air flow rate. The influence of the aerodynamic resistance of an airflow meter on air flow rate is taken into account with the help of a correction that must be introduced into the values measured.

scholarly journals Development of an air conditioning system with individual regulation of temperature and air flow rate in a compartment of a passenger car

2021 ◽  
Vol 80 (1) ◽  
pp. 30-34
Author(s):  
G. M. STOYAKIN ◽  
A. V. KOSTIN ◽  
S. N. NAUMENKO
Keyword(s):  
Air Temperature ◽  
Flow Rate ◽  
Air Conditioning ◽  
Air Flow ◽  
Three Dimensional ◽  
Air Flow Rate ◽  
Passenger Cars ◽  
Air Conditioning System ◽  
Air Supply ◽  
Individual Regulation

Maintaining optimal parameters of the microclimate in the car along the route is the most important requirement for the passenger’s travel. In the 1st class passenger cars, maintaining optimal microclimate parameters is achieved through the operation of the air conditioning system, which provides individual regulation of the air temperature in each compartment. Individual air temperature control systems used in air conditioning systems are divided into two groups: active and passive.The article proposes for consideration a combined active-passive system with a separate air supply with a lower and higher temperature compared to the temperature maintained in the compartment and the installation of individual induction terminals, which makes it possible to increase the efficiency of individual regulation of air parameters in the compartment.To assess the uniformity of temperature distribution and air flow rate over the car volume with the proposed control scheme, a three-dimensional modeling of the distribution of these parameters in the compartment was carried out on the basis of Autodesk CFD software.The given simulation results indicate the uniformity of temperature and air flow rate distribution over the compartment volume, which makes it possible to characterize the proposed system as sufficiently energy efficient, easy to operate and reliable in operation.

Sign in / Sign up

Export Citation Format

Share Document