Experimental and numerical evaluation of a two-stage indirect/thermoelectric assisted direct evaporative cooling system

2021 ◽  
Vol 248 ◽  
pp. 114780
Author(s):  
Yuanyuan Zhou ◽  
Zhen Yan ◽  
Qiumin Dai ◽  
Yanshun Yu
Keyword(s):  
Numerical Evaluation ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Two Stage ◽  
Direct Evaporative Cooling ◽  
Evaporative Cooling System

scholarly journals Two Stage Evaporative Cooling of Residential Building Using Geothermal Energy

2019 ◽  
Vol 25 (4) ◽  
pp. 29-44
Author(s):  
Ali Hammoodi Mahdi Alhosainy ◽  
Issam Mohammed Ali Aljubury
Keyword(s):  
Groundwater Flow ◽  
Temperature Difference ◽  
Geothermal Energy ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Residential Building ◽  
Two Stage ◽  
Second Stage ◽  
Direct Evaporative Cooling ◽  
Evaporative Cooling System

The weather of Iraq has longer summer season compared with other countries. The ambient temperature during this season reaches over 50 OC which makes the evaporative cooling system suitable for this climate. In present work, the two-stage evaporative cooling system is studied. The first stage is indirect evaporative cooling (IEC) represented by two heat exchangers with the groundwater flow rate (5 L/min). The second stage is direct evaporative cooling (DEC) which represents three pads with groundwater flow rates of (4.5 L/min). The experimental work was conducted in July, August, September, and October in Baghdad. Results showed that overall evaporative efficiency of the system (two coils with three pads each pad of 3cm) reach to 167 % with the temperature difference between ambient and supply is 26.2oC. While it reached 122.7% (one coil with three pads ) with the temperature difference between ambient and supply is 16OC and reduced to 84.88% and 84.36% for IEC and DEC respectively.  

scholarly journals A MATHEMATICAL MODEL FOR DIRECT EVAPORATIVE COOLING AIR CONDITIONING SYSTEM

2003 ◽  
Vol 2 (2) ◽  
Author(s):  
J. R. Camargo ◽  
C. D. Ebinuma ◽  
S. Cardoso
Keyword(s):  
Mathematical Model ◽  
Air Conditioning ◽  
Cooling System ◽  
Convective Heat Transfer Coefficient ◽  
Evaporative Cooling ◽  
Experimental Tests ◽  
Water Evaporation ◽  
Human Thermal Comfort ◽  
Direct Evaporative Cooling ◽  
Evaporative Cooling System

Air conditioning systems are responsible for increasing men's work efficiency as well for his comfort, mainly in the warm periods of the year. Currently, the most used system is the mechanical vapor compression system. However, in many cases, evaporative cooling system can be an economical alternative to replace the conventional system, under several conditions, or as a pre-cooler in the conventional systems. It leads to a reduction in the operational cost, comparing with systems using only mechanical refrigeration. Evaporative cooling operates using induced processes of heat and mass transfer, where water and air are the working fluids. It consists in water evaporation, induced by the passage of an air flow, thus decreasing the air temperature. This paper presents the basic principles of the evaporative cooling process for human thermal comfort, the principles of operation for the direct evaporative cooling system and the mathematical development of the equations of thermal exchanges, allowing the determination of the effectiveness of saturation. It also presents some results of experimental tests in a direct evaporative cooler that take place in the Air Conditioning Laboratory at the University of Taubaté Mechanical Engineering Department, and the experimental results are used to determinate the convective heat transfer coefficient and to compare with the mathematical model.

Correlation of Direct Evaporative Cooling Efficiency With Media Porosity

2010 ◽  
Author(s):  
James Walker ◽  
Shenguang Sheng ◽  
A. G. Agwu Nnanna ◽  
Lincang Li
Keyword(s):  
Cooling System ◽  
Evaporative Cooling ◽  
Direct Evaporative Cooling ◽  
Evaporative Cooling System ◽  
Mass Flow Rates ◽  
The Media ◽  
To Come ◽  
Temperature Constant ◽  
Wetted Surface Area ◽  
Air Conditioning Systems

. Energy consumption of HVAC&R could be reduced by integrating evaporative cooling device into air conditioning systems. Direct Evaporative Cooling (DEC) are suited for climates where the air is hot and humidity is low. In DEC, heat is absorbed whenever water is evaporated and converted to water vapor. By passing through or around a wetted surface, heat is removed from the surrounding air in the vaporization of the water. The process approximates the adiabatic-saturation process and the path lies on a constant wet-bulb temperature which is a constant enthalpy line. The wetted surface area in direct evaporative cooling depends on porosity and absorptivity of the media. This paper evaluates the effect of media porosity on performance of a Direct Evaporative Cooling system. In this experimental work, the porosity is varied by changing the packing density and volume of media. The packing material allows air and water to come in direct contact. Holding all other variables like mass flow rates and inlet dry-bulb temperature constant, the effect Porosity on DEC performance is studied. The performance of DEC system is a function of porosity, dry- and wet-bulb temperatures and relative humidity. Efficiency increases with porosity.

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