scholarly journals Effect of pad water flow rate on evaporative cooling system efficiency in laying hen housing

2020 ◽  
Vol 51 (4) ◽  
pp. 209-219
Author(s):  
Mohamed Saied Ghoname

An experiment was conducted in three commercial laying hen houses with 32-week-old hens in the summer of 2017 in a commercial farm in Gharbia Province, Egypt (31.06ºN, 31.16ºE) using an evaporative pad cooling system to determine the most suitable water flow rate for maintaining indoor air temperature within the thermal comfort zone. The experiment was conducted using three different water flow rates, i.e. 4.76, 5.65, and 6.35 L min–1.m–2, to assess the effect of different water flow rates on evaporative pad cooling system performance and determine the most suitable water flow rate for maintaining the thermal comfort zone of laying hens. The evaporative pad cooling system maintained the mean indoor air temperature below 28°C. The mean indoor air relative humidity during the experimental period ranged from 72.6 to 73.8%. The 4.76 L min–1.m–2 water flow rate resulted in the highest saturation efficiency (ca. 73.75%). In contrast, the 6.35 L min–1 m–2 water flow rate resulted in the lowest saturation efficiency (70.63%). The mean cooling energy values were 69.11, 66.0, and 66.65 kwh for water flow rates of 4.76, 5.56, and 6.35 Lmin–1m–2, respectively. The highest temperature-humidity index was 27.78°C, which indicated that birds were not stressed in all treatments.

2020 ◽  
Vol 10 (3) ◽  
pp. 810 ◽  
Author(s):  
Jinfang Zhang ◽  
Zeyu Li ◽  
Yue Jing ◽  
Yongrui Xu

The solar absorption-subcooled compression hybrid cooling system (SASCHCS) is tech-economically feasible for high-rise buildings. Since such a system operates with no auxiliary heat source, the performance coupling of its absorption subsystem and solar collectors is sensitive to the variation of hot water flow rate. In this regard, the relationship of system performance and hot water flow rate is required to be clarified exactly. Therefore, this paper aims to illustrate the effect mechanism of hot water flow rate and to propose the corresponding decision criterion. The case study is based on a typical high-rise office building in subtropical Guangzhou. The daily working process of this system with different hot water flow rates is simulated and analyzed. Subsequently, the useful heat of collectors and cooling capacity of the absorption subsystem with the hot water flow rate is discussed in detail. The results show that the SASCHCS operates with hot water temperatures ranging from 60 °C to 90 °C. The energy saving increases with the rise of hot water flow rate, but such variation tends to be flat for the excessively high flow rate. As the collector flow rate increases from 1 m3/h to 10 m3/h, the daily energy saving improves by 21% in August. Similarly, the daily energy saving increases by 37.5% as generator hot water flow rate increases from 1 m3/h to 10 m3/h. In addition, the collector flow rate of 3.6 m3/h (13.33 (kg/m2 h)) and the generator flow rate of 5.2 m3/h (19.26 (kg/m2 h)) are optimal for the annual operation, with considering power consumption of water pumps. This paper is helpful for the improvement of SASCHCS operating performance.


2014 ◽  
Vol 905 ◽  
pp. 263-267
Author(s):  
Shin Ku Lee ◽  
W.H. Lo ◽  
M.C. Ho ◽  
T.H. Lin

The hybrid inverse method to estimate the optimal water flow rate and surface temperature on the hot surface of the steel roller shutter with water film cooling system subjected to a fire environment is presented in this paper. The results show that the effect of the down-flowing water film flow rate on the present estimates cannot be negligible. The water-film system combined with the steel roller shutter can effectively improve the heat resistance and the temperature of the shutter slat surface can be controlled to around 100 °C. The optimal water flow rate is 110 L/min for a typical 3m x 3m steel roller shutter with water film cooling system.


2003 ◽  
Vol 125 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Akihiko Hirano ◽  
Michiyoshi Yamamoto ◽  
Katsumi Sakaguchi ◽  
Tetsuo Shoji ◽  
Kunihiro Iida

The flow rate of water flowing on a steel surface is considered to be one of the important factors strongly influencing the fatigue life of the steel, because the water flow produces difference in the local environmental conditions. The effect of the water flow rate on the fatigue life of a carbon steel was thus investigated experimentally. Fatigue testing of the carbon steel was performed at 289°C for various dissolved oxygen contents (DO) of less than 0.01 and 0.05, 0.2, and 1 ppm, and at various water flow rates. Three different strain rates of 0.4, 0.01, and 0.001 %/s were used in the fatigue tests. At the strain rate of 0.4 %/s, no significant difference in fatigue life was observed under the various flow rate conditions. On the other hand, at 0.01 %/s, the fatigue life increased with increasing water flow rate under all DO conditions, such that the fatigue life at a 7 m/s flow rate was about three times longer than that at a 0.3 m/s flow rate. This increase in fatigue life is attributed to increases in the crack initiation life and small-crack propagation life. The major mechanism producing these increases is considered to be the flushing effect on locally corrosive environments at the surface of the metal and in the cracks. At the strain rate of 0.001 %/s, the environmental effect seems to be diminished at flow rates higher than 0.1 m/s. This behavior does not seem to be explained by the flushing effect alone. Based on this experimental evidence, it was concluded that the existing fatigue data obtained for carbon steel under stagnant or relatively low flow rate conditions may provide a conservative basis for fatigue life evaluation. This approach seems useful for characterizing fatigue life evaluation by expressing increasing fatigue life in terms of increasing water flow rate.


1979 ◽  
Author(s):  
R. D. Ingebo

Axial and swirling airflows were used to break up water jets and sheets into sprays of droplets to determine the overall effects of orifice diameter, weight flow of air, and the use of an air swirler on fineness of atomization as characterized by mean drop size. A scanning radiometer was used to determine the mean drop diameter of each spray. Swirling airflows were produced with an axial combustor, 70-deg brake angle, air swirler. Water jets were injected axially upstream, axially downstream and cross stream into the airflow. In addition, pressure atomizing fuel nozzles which produced a sheet and ligament type of breakup were investigated. Increasing the weight flow rate of air or the use of an air swiler markedly reduced the spray mean drop size. Test conditions included a water flow rate of 68.0 liter per hour and airflow rates (per unit area) of 3.7 to 25.7 g per square cm per sec, at 293 K and inlet-air static pressures of 1.01 × 105 to 1.98 × 105 N/m2.


Author(s):  
Luis R. Figueroa Ibarra ◽  
J. Hugo Rodri´guez Marti´nez ◽  
Marcelino Santaba´rbara Botello

This paper details the design of a Pitot tube used for water flow rate measurements in large pipes. The paper describes first the nowadays commonly used device (simplex pitot), based on standard CTI Code ATC-105 from Cooling Tower Institute [1]. The disadvantages of the simplex pitot are pointed out, and the detailed description of the proposed device (multiport pitot) is explained. The Multiport Pitot, which design is also based on norm ATC-105, is able to perform real-time measurements. The paper also includes the results obtained from the water flow rate measurements made in the cooling system of a thermal power plant in Mexico. These measurement results were compared to simulation results obtained with a computational commercial simulation tool.


2016 ◽  
Vol 61 (4) ◽  
pp. 793-807 ◽  
Author(s):  
Nikodem Szlązak ◽  
Dariusz Obracaj ◽  
Justyna Swolkień ◽  
Kazimierz Piergies

Abstract In Polish underground mines in which excavations are subjected to high heat load, central and group cooling systems based on indirect cooling units are implemented. Chilled water, referred to as cold water and produced in chillers, is distributed through a pipeline network to air coolers located in mining and development districts. The coolers are often moved to other locations and the pipeline network undergoes constant modification. In such a system, parameters of cold water in different branches of the pipeline network need to be controlled. The article presents the principles for controlling the cooling capacity of air coolers installed in an underground mine. Also, the authors propose automatic control of water flow rate in underground pipeline network and in particular coolers, depending on the temporary cooling load in the system. The principles of such a system, controlling cold water distribution, and the functions of its individual components are described. Finally, an example of an automatic control of water flow rate in a central cooling system currently implemented in a mine is presented.


2013 ◽  
Vol 664 ◽  
pp. 931-935 ◽  
Author(s):  
Banyat Niyomvas ◽  
Bunjerd Potakarat

The efficiency of an evaporative cooler on different cooling pads have been studied. Two type of cooling pads made of a curtain fabric and a raw cotton fabric were comparatively studied. The effect of blower speeds at 725, 1015 and 1450 RPM and water flow rate of 26.9 liters per minute were investigated. The results showed that an average of the different temperature between inlet and outlet were 2.9 oC and 1.7 oC for a curtain fabric and a raw cotton fabric, respectively. Saturation efficiency of the cooling pads made of a curtain fabric was in the ranges of 46.3 to 61.3% or represents an average of 54.8%, and 29.7 to 39.2% or represents an average of 33.2% for a raw cotton fabric.


2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 68-69
Author(s):  
Hannah E Miller ◽  
Jorge Y Perez-Palencia ◽  
Crystal L Levesque ◽  
Robert C Thaler

Abstract A survey of South Dakota pork producers in 2019 demonstrated that water flow rate for nipple drinkers was highly variable among barns. Sixty-eight percent had water flow rates above the recommended rate of 500–1,000 mL/min (NSNG, 2010). The objective of this study was to determine the impact of water flow rate on finishing pig performance during the summer months. A total of 396 mixed-sex pigs, in two groups, were utilized in a 77-day trial (34.55 to103.8 kg BW) with 6 pigs/pen. Pens were assigned to one of three water flow rates (high, medium, low) based on the 3-hole diameters of the commercial water nipples used in the facility (2.0, 1.0, 0.80 mm; n = 22 pens/treatment). Daily water usage was recorded for each treatment along with room temperature, outside temperature, and relative humidity. Individual pen water flow rate was recorded every two weeks. At every diet phase change (26± 2.6 days), feed disappearance and individual pig body weight were recorded. Water flow rates averaged 1846±188, 906±214, 508±100 mL/min for high, medium, and low flow rates, respectively. Daily water disappearance for high, medium, and low treatments were 6.8, 2.3, 1.7±3.2 liters/pig, respectively. Final body weight (BW; 103.8±7.4 kg) did not differ. Daily gain (ADG) from 34.5±4.5 to 55.5±4.6 kg BW was greatest (P < 0.05) for high treatment. Daily intake (ADFI) and gain:feed (G:F) from 55.5±4.6 to 79.1±5.3 kg BW were greatest (P < 0.05) for high treatment. Cumulative ADFI was 2.27, 2.18, 2.16±0.16 kg (P < 0.05) in high, medium, and low flow ranges, respectively. There was no differences in cumulative ADG or G:F. Water flow rate had a significant impact on ADFI although there was minimal impact on gain and G:F. Water nipples should be regularly checked as part of normal barn maintenance to ensure adequate, but not excessive, water is available.


2021 ◽  
Vol 35 (4) ◽  
pp. 24-32
Author(s):  
Jae Geun Jo ◽  
Chi Young Lee

In this study, the thermal radiation attenuation performance of water mist was investigated using twin-fluid atomizers. The water and air flow rates of Small atomizer were 36~105 g/min and 10~30 L/min, whereas those of Large atomizer were 37~300 g/min and 20~60 L/min, respectively. In the present experimental range, the thermal radiation attenuation of Small atomizer and Large atomizer were 6.1~11.9% and 5.2~14.6%, respectively. With the increase in water and air flow rates, the thermal radiation attenuation increased, and under similar water and air flow rate conditions, Small atomizer showed higher thermal radiation attenuation than Large atomizer. Based on the present experimental data, it was found that the air (gas) discharge area is a potentially important factor in determining the thermal radiation attenuation performance. Additionally, through the analysis of thermal radiation attenuation per unit water flow rate, it was confirmed that the twin-fluid atomizer can result in higher thermal radiation attenuation than the single-fluid atomizer under the same water flow rate condition.


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