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Optimizing Water Droplet Diameter of Spray Cooling for Dairy Cow in Summer Based on Enthalpy Difference Theory
- Source :
- Energies, Vol 12, Iss 19, p 3637 (2019), Energies; Volume 12; Issue 19; Pages: 3637
- Publication Year :
- 2019
- Publisher :
- MDPI AG, 2019.
-
Abstract
- Spray cooling is widely used in relieving heat stress in dairy cows during summer, in which the cooling effect is highly correlated to the diameter of water droplet. To optimize the average diameter of spraying droplet (ADSD) in the process of heat transfer, a theoretical analysis was performed based on the enthalpy difference theory in this study. A platform was built to simulate the processes of spray cooling and its heat stress alleviation to dairy cows in field, and a field experiment was applied to verify the diameter of water droplets suitable for spray cooling. Heat exchange was calculated for eighteen different ADSD in three different environment conditions in the laboratory. The spraying droplets with eighteen diameters were formed by using six different nozzles under the combinations of three pressures and two wind speeds conditions, which were controlled by heaters. The relationship between the ADSD and heat exchange was established with the purpose to determine the appropriate diameter for practical production. In the field test, body temperature, rectal temperature, and respiratory rate of dairy cows were monitored, and the heat exchange was analyzed to verify the optimal diameter spraying cooling in summer. Results showed that the heat exchange generally increased as ADSD increased, and maximum heat exchanges were reached when the ADSD was averaged at 0.914 mm and 0.995 mm, under which the models of the corresponding nozzles were 9080 and 9010, respectively. After that, the heat exchange decreased as the ADSD continued to increase. Field experiment indicated that the best cooling effect could be achieved with the ADSD of 0.947 mm, and the water consumption for spray cooling was reduced by 22.8% under the scenario.
- Subjects :
- enthalpy difference theory
Control and Optimization
Materials science
Renewable Energy, Sustainability and the Environment
Spray cooling
lcsh:T
Field experiment
Enthalpy
Nozzle
diameter of spray droplet
heat and mass transfer
water consumption
Energy Engineering and Power Technology
lcsh:Technology
Wind speed
Mass transfer
Heat exchanger
Heat transfer
Electrical and Electronic Engineering
Composite material
Engineering (miscellaneous)
Energy (miscellaneous)
Subjects
Details
- Language :
- English
- ISSN :
- 19961073
- Volume :
- 12
- Issue :
- 19
- Database :
- OpenAIRE
- Journal :
- Energies
- Accession number :
- edsair.doi.dedup.....0898532e9af22ab30fd6f108b95c2407