scholarly journals The effect of air velocity on the performance of the direct evaporative cooling system

2022 ◽  
Vol 1217 (1) ◽  
pp. 012016
Author(s):  
Z Hassan ◽  
M S Misaran ◽  
N J Siambun ◽  
M Adzrie
Keyword(s):  
Cooling System ◽  
Evaporative Cooling ◽  
Cooling Capacity ◽  
Airflow Rate ◽  
Cooling Efficiency ◽  
Air Velocity ◽  
Input And Output ◽  
Direct Evaporative Cooling ◽  
Evaporative Cooling System ◽  
Air Speed

Abstract This experimental study aimed to determine the effect of airflow velocity on the performance of a direct evaporative cooling system. Rectangular-shaped honeycomb cooling pads with a length of 34 cm, a width of 25 cm, and a thickness of 3.5 cm are used as cooling media. The main parameters of the study are low air velocity (2.3 ms−1), medium (3.2 ms−1), and high velocity (3.7 ms−1). The data collected include dry bulb temperature, wet bulb temperature, output air temperature, input and output air velocity, input and output humidity, and solar radiation. These data are used to determine saturation efficiency, cooling capacity, temperature decreases, and feasibility index. The experimental results are presented in the form of tables and graphs and analysed based on existing theories. The results showed that the evaporative cooling system could produce output temperatures up to 27.5°C with input 31.4°C at low airspeed, 27.97°C with input 31.47oC at medium speed, and 27.7°C with input 31.30°C at high air speed. It was concluded that a low airflow rate would add to the cooling efficiency, and the higher the airflow rate, the lower the cooling efficiency. The results showed that evaporative cooling is achievable with a feasibility index of 19.89 ≤ F*≤ 20.67. The results also affirmed that cooling capability is higher where the feasibility indexes are comparatively low.

scholarly journals Comparison on cooling efficiency of cooling pad materials for evaporative cooling system

2018 ◽  
Vol 1 (1) ◽  
pp. 61-68
Author(s):  
Radhiyah Abd. Aziz ◽  
Nurul Farahin Zamrud ◽  
Nurrina Rosli
Keyword(s):  
Cooling System ◽  
Evaporative Cooling ◽  
Carbon Foam ◽  
Vital Role ◽  
Cooling Efficiency ◽  
Air Flow Rate ◽  
Data Logger ◽  
Direct Evaporative Cooling ◽  
Evaporative Cooling System ◽  
Using Data

This research aims to examine on cooling efficiency of different type natural based material as a cooling pad for evaporative cooling system. Efficiency of direct evaporative cooling system mostly depends on the cooling pad and hence, the material used in the cooling pad plays a very vital role. Here, two types of natural based materials (activated carbon foam and luffa pad) were selected to be used as cooling pad. Those materials pad are then fabricated to fit into the evaporative cooling setup. Temperature, and humidity are the most important data in this experimental analysis. The readings of these terms are taken for each type of cooling pad using data logger and also, the further calculations are done based on these readings. The material of the cooling pad and the air flow rate are varied to observe the effect on their cooling efficiency. From the analysis, the ACF cooling pad shows better cooling efficiency compared to that of luffa pad.

scholarly journals Evaporative cooling efficiency of pads consisting of vegetable loofah

2019 ◽  
Vol 10 (1) ◽  
pp. 38-44 ◽  
Author(s):  
Júlio César Ferreira de Melo Júnior ◽  
João Victor Martins Bamberg ◽  
Neiton Silva Machado ◽  
Emanuelly Nadja Gomes Caldas ◽  
Marcos Sales Rodrigues
Keyword(s):  
Cooling System ◽  
Evaporative Cooling ◽  
Cooling Efficiency ◽  
Air Flow Rate ◽  
Direct Evaporative Cooling ◽  
Alternative Materials ◽  
Before And After ◽  
Evaporative Cooling System ◽  
Sources Of Variation ◽  
Adjusted Model

Brazilian agroindustry has presented constant innovations in the use of equipment and materials, among which are those that generate artificial thermal conditioning inside the zootechnical facilities, through a direct evaporative cooling system (DEC). In order to mitigate the effects of high temperatures associated with low air humidity in buildings in the northeastern region of Brazil, the use of DEC systems is evident. Therefore, DEC’s built with evaporative pads constituted of alternative materials, prove to be an interesting and viable alternative. The aim of this work was to evaluate the cooling efficiency of the evaporative pads constituted of vegetable loofah. The experiment was performed at the Campus de Ciências Agrárias, Federal University of the São Francisco Valley (UNIVASF) in Petrolina, Pernambuco state. The experimental design was in randomized blocks, in a 4x4 factorial scheme, with 13 replicates. Air temperature and relative humidity values were collected before and after the passage through the pad for different flow velocities and pad thicknesses, in order to calculate the evaporative efficiency. The variance analysis was significant at 5% probability for the sources of variation of the pad thickness (0.05, 0.075, 0.1 and 0.125 m) and the air flow rate (0.076, 0.264, 0.459 and 0.773 m s-1), and the interactions. The highest efficiency, 57.0% was observed for the interaction between the thickness of 0.125 m and the speed of 0.773 ms-1 as adjusted model.

Test Analysis of Performance of the Direct Evaporative Cooling Air Conditioners

2013 ◽  
Vol 827 ◽  
pp. 298-301
Author(s):  
Jian Zhang
Keyword(s):  
Relative Humidity ◽  
Evaporative Cooling ◽  
Cooling Capacity ◽  
Cooling Efficiency ◽  
Air Conditioner ◽  
Test Analysis ◽  
Air Conditioners ◽  
Direct Evaporative Cooling ◽  
Cooling Air ◽  
Analysis Of Performance

The direct evaporative cooling conditioner experimental research is carried out in this paper. Analyze the influence of inlet air dry ball temperature and relative humidity to air conditioner cooling capacity and cooling efficiency, which has certain guiding significance to improve the direct evaporative cooling air conditioner 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 Performance Analysis of a Desiccant Evaporative Cooling System for Mango Fruit Storage in the Savannah and Transitional Zones of Ghana

2019 ◽  
Vol 23 (3) ◽  
pp. 1-14
Author(s):  
Awafo Edward ◽  
Addo Ahmad ◽  
Bart-Plange Ato
Keyword(s):  
Performance Analysis ◽  
Water Flow ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Airflow Rate ◽  
Fruit Storage ◽  
Flow Rates ◽  
Evaporative Cooling System ◽  
Line Slope ◽  
Best Fit

AbstractPerformance analysis of a 1.0 tonne desiccant evaporative cooling storage structure for mango fruits was studied. The study examined the effects of inlet air conditions and water flow rates through an absorber on the cooling performance of the system. The airflow rate was approximately 0.24 m3·s−1 and water flow rates through the absorber varied from 0 to 0.252 l·s−1. The system produced approximately 7 kW of cooling at water supply rate of 0.252 l·s−1. A simple linear correlation was established for condition line slope from inlet to exiting air conditions for all the water flow rates. Lines of best fit resulted in correlation coefficient better than 0.96. The observed temperatures with a direct evaporative cooler, tested with freshly harvested mango fruits were found to be between 15.1°C and 23.4°C and relative humidity between 81.8% and 97.7%. Physiological weight loss and firmness assessments of the fruits were also conducted.

Sign in / Sign up

Export Citation Format

Share Document