Study of synergy between photovoltaic, thermoelectric and direct evaporative cooling system for improved performance

2021 ◽  
Author(s):  
V.S. Poddar ◽  
V.A. Ranawade ◽  
N.B. Dhokey
Keyword(s):  
Cooling System ◽  
Evaporative Cooling ◽  
Direct Evaporative Cooling ◽  
Evaporative Cooling System ◽  
Improved Performance

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.

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 Experimental Investigation of Thermal Performance of Aluminum Foil Coated with Polyester in a Direct Evaporative Cooling System

2021 ◽  
Vol 27 (4) ◽  
pp. 1-15
Author(s):  
Abbas Magid Taleb ◽  
Mohammed Abdulraouf Nima
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Relative Humidity ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Aluminum Foil ◽  
Adiabatic Process ◽  
Direct Evaporative Cooling ◽  
Evaporative Cooling System ◽  
Positive Impression

An experimental study was carried out for an evaporative cooling system in order to investigate the effect of using an aluminum pad coated with fabric polyester. In the present work, it was considered to use a new different type of cooling medium and test its performance during the change in the wet-bulb temperature and dry-bulb temperature of the supply air outside of the pad, the relative humidity of the supply air, the amount of air supplied (300-600) CFM and also the change of the amount of circulated water (1.75, 2.5, 4.5) liter per minute. A decrease in the WBT of the air was obtained, whereas the WBT of the air entering the pad was 26.5 . In contrast, the WBT of the outside air had reached 23  even though evaporative cooling is an adiabatic process which makes the WBT of the air that comes out of the pad is equal to the entering air WBT. The decrease in DBT is by changing the amount of air and water passing through the aluminum pad, whereas the DBT of the air entering the pad was 45 , while the DBT of the outside air had reached 29 . Also, an essential thing was obtained as this rise in the relative humidity of the air is very small 57%RH compared to the conventional pads, and this gives a positive impression as the air supplied from this pad has less moisture and its ability to carry moisture is much higher than that of air supplied from other pads. This gives a positive impression because the air supplied from this pad has lower humidity and its ability to hold moisture much higher than the air supplied from other traditional pads.

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