scholarly journals Enhancement of Poly-Crystal PV Panels Performance by Air-to-Air Heat Exchanger Cooling System

2021 ◽  
Vol 16 ◽  
pp. 157-163
Author(s):  
Khaleel Abushgair
Keyword(s):  
Heat Exchanger ◽  
Cooling System ◽  
Ambient Air ◽  
Bottom Surface ◽  
Solar Panels ◽  
Pv System ◽  
System A ◽  
Pv Module ◽  
Back Panel ◽  
The Impact

The temperature of silicon Poly-Crystal photovoltaic (PV) solar panels has a significant impact on their efficiency emphasizing the necessity of cooling approach to be used. The current study looked at the impact of adopting a unique forced convictive air-to-air heat exchanger as a cooling approach to boost the efficiency of PV solar panels, as efficiency of silicon Poly-Crystal PV solar panels would decrease as its temperature increased. The research was carried out experimentally with both an uncooled and cooled PV system. A unique cooling system for PV panels was designed and experimentally investigated in Amman, Jordan included a heat exchanger connected to a blower that drove ambient air over the back-panel surface and a chimney to draw the cooled air outside. This cooling system would improve the PV panel's efficiency. It was found that by directing cooled air over the bottom surface of the PV module at an ideal rate of 0.01020 m3/s, the temperature of the PV module could be reduced from an average of 40 °C (without cooling) to 34 °C. As a result, the efficiency and output power of PV modules increased by roughly 2 % and 12.8 %, respectively.

Analysis of a Solar Space Cooling System Using Liquid Desiccants

1990 ◽  
Vol 112 (4) ◽  
pp. 246-250 ◽  
Author(s):  
P. Gandhidasan
Keyword(s):  
Heat Exchanger ◽  
Cooling System ◽  
Cooling Water ◽  
Ambient Air ◽  
Solution Concentration ◽  
Simple Expression ◽  
Ventilation Mode ◽  
Cooling Water Temperature ◽  
System A ◽  
Space Cooling

For tropical countries, solar space cooling is an attractive proposition. Dehumidification of air in hot, humid climates is almost as important as cooling. Removal of moisture from the air is much easier to achieve than cooling the air. The proposed cooling system operates on the ventilation mode. The ambient air is dehumidified using liquid desiccants followed by adiabatic evaporative cooling. The desiccant soon becomes saturated with the water extracted from the air and can be regenerated by using solar energy. For this system, a simple expression is derived in this paper to predict the amount of heat removed from the space to be conditioned in terms of known initial parameters through a simplified vapor pressure correlation and effectiveness of the dehumidifier and the heat exchanger. The effect of ambient air conditions, solution concentration, the cooling water temperature and the effectiveness of the dehumidifier and the heat exchanger on the performance of the cooling system are also discussed in this paper.

Liquid-Coupled Indirect-Transfer Exchanger Application to the Diesel Engine

1979 ◽  
Vol 101 (4) ◽  
pp. 516-523 ◽  
Author(s):  
James C. Eastwood
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Cooling System ◽  
Relative Effectiveness ◽  
Ambient Air ◽  
Air Cooling ◽  
Performance Curves ◽  
Air Cooling System ◽  
Cooling Function ◽  
Low Charge

The efficiency of turbocharged diesel engines can be increased by cooling the charge air. This paper presents a design approach for liquid-coupled indirect-transfer heat exchanger systems to perform the air-cooling function. The two advantages most commonly cited for this approach to charge-air cooling are (1) the heat exchangers involved are easily packaged so that their shapes can be controlled by judicious design, and (2) simple gas ducting allows for compact machinery arrangements and relatively low charge-air pressure drop. An analytical approach to the design of liquid-coupled indirect-transfer heat exchanger systems is presented. Performance curves are constructed on the basis of this analysis. Four important design conditions are evident from the observation of these performance curves including (1) the relative capacity rate combination of the three fluids (ambient air, coupling liquid, and engine charge-air) which yields the highest overall effectiveness, (2) an optimum coupling-liquid flow rate, (3) the relative effectiveness distribution for each of the two component heat exchangers (hot and cold components), and (4) a broad design range for the optimum area distribution between the hot and cold exchangers. These performance curves serve as a guide for the design of a liquid-coupled charge-air cooling system.

Airflow Uniformity Through Perforated Tiles in a Raised-Floor Data Center

2005 ◽  
Author(s):  
James W. VanGilder ◽  
Roger R. Schmidt
Keyword(s):  
Data Center ◽  
Cooling System ◽  
Design Parameters ◽  
Airflow Rate ◽  
Simple Estimate ◽  
Cfd Models ◽  
System A ◽  
Data Center Cooling ◽  
Floor Plans ◽  
The Impact

The maximum equipment power density (e.g. in power/rack or power/area) that may be deployed in a typical raised-floor data center is limited by perforated tile airflow. In the design of a data center cooling system, a simple estimate of mean airflow per perforated tile is typically made based on the number of CRAC’s and number of perforated tiles (and possibly a leakage airflow estimate). However, in practice, many perforated tiles may deliver substantially more or less than the mean, resulting in, at best, inefficiencies and, at worst, equipment failure due to inadequate cooling. Consequently, the data center designer needs to estimate the magnitude of variations in perforated tile airflow prior to construction or renovation. In this paper, over 240 CFD models are analyzed to determine the impact of data-center design parameters on perforated tile airflow uniformity. The CFD models are based on actual data center floor plans and the CFD model is verified by comparison to experimental test data. Perforated tile type and the presence of plenum obstructions have the greatest potential influence on airflow uniformity. Floor plan, plenum depth, and airflow leakage rate have modest effect on uniformity and total airflow rate (or average plenum pressure) has virtually no effect. Good uniformity may be realized by using more restrictive (e.g. 25%-open) perforated tiles, minimizing obstructions and leakage airflow, using deeper plenums, and using rectangular floor plans with standard hot aisle/cold aisle arrangements.

Impact of Manifold Design on Heat Exchanger Efficiency

1997 ◽  
Vol 119 (2) ◽  
pp. 357-362
Author(s):  
D. K. Harris ◽  
D. G. Warren ◽  
V. W. Goldschmidt
Keyword(s):  
Heat Exchanger ◽  
Internal Flow ◽  
Heating System ◽  
Operating Conditions ◽  
Baseline Design ◽  
System A ◽  
Numerical Predictions ◽  
Forced Air ◽  
And Behavior ◽  
The Impact

The impact of manifold design on single-phase heat exchanger effectiveness is studied using the NTU-Effectiveness method. Manifolds are devices that redistribute the internal flow stream of a heat exchanger from one to several passages. Two manifold types are identified: collector box and direct split designs. The particular application considered is that of a gas fired forced air heating system. A general enhancement analysis is performed which covers four different combinations of performance and objective criteria. Three cases involve increasing the heat exchanger effectiveness while constraining either the internal flow head loss, the internal mass flow rate, or their product. The other case involves reducing the required heat exchanger flow length while constraining the heat transfer rate. Familiar convection correlations are then incorporated into the enhancement analysis to predict general trends and behavior when the main tube is split into several smaller tubes. Analytical estimates of improved effectiveness are presented for three operating conditions of an actual heat exchanger which possesses a manifold. Experimental data acquired from the gas-to-gas heat exchanger are compared to numerical predictions of its performance without a manifold (baseline design). The analytical equations developed closely predict the improvement in heat exchanger effectiveness.

Biofiltration of dichlorobenzenes

2001 ◽  
Vol 44 (9) ◽  
pp. 287-293 ◽  
Author(s):  
F. Roberge ◽  
M.J. Gravel ◽  
L. Deschênes ◽  
C. Guy ◽  
R. Samson
Keyword(s):  
Gas Phase ◽  
Contaminated Soil ◽  
Cooling System ◽  
Ambient Air ◽  
Animal Manure ◽  
Full Scale ◽  
Peat Moss ◽  
Aerobic Treatment ◽  
Load Variations ◽  
System A

The use of air biofiltration for the degradation of dichlorobenzenes (1,2-DCB and 1,4-DCB) was studied at a refinery site. At this plant, 93 m3/h of contaminated groundwater, used in a cooling system and containing a maximum of 2 ppm of dichlorobenzenes, had to be treated. Stripping of the DCBs followed by biofiltration was selected as the most suitable technology to avoid volatilization in ambient air as expected with a wastewater aerobic treatment system. A stripper of 15 m height and 1.27 m diameter was designed as a first step treatment to volatilize DCBs with 3400 m3/h of air. Two full-scale biofilters of 70 m3 each were built and filled with 45 m3 of filtering media for the adsorption and biodegradation of the DCBs in the gas-phase. Filtering media was composed mainly of peat moss, with animal manure, wood chips and DCBs contaminated soil. Air to be treated was also contaminated with naphthalene. Laboratory tests showed an effective microbial activity in the contaminated soil and in the filtering media for DCBs degradation. Degradation of naphthalene induced slower degradation of DCBs. Full-scale operation was studied during four months. Water flow and DCBs content in the water entering the stripper were lower than expected with only 57 m3/h and a maximum concentration of only 240 ppb. Effective desorption was obtained in the stripper in the full-scale operation (more than 99% removal). Full-scale biofilters maintained a DCB concentration of less than 1 ppmv in the air outlet, but removal efficiency varied between 0 and 79% because of the low DCB inlet concentrations, load variations and sporadic naphthalene presence.

scholarly journals Basic design of a cooling system for nylon 6, 6 process

2018 ◽  
Vol 7 (3) ◽  
pp. 977
Author(s):  
Karthik Silaipillayarputhur Ph. D ◽  
Nasser Al Mulhim ◽  
Abdullah Al Mulhim ◽  
Mohammed Arfaj ◽  
Ahmed Al Naim
Keyword(s):  
Heat Exchanger ◽  
Rate Ratio ◽  
Cooling System ◽  
Ambient Air ◽  
Nylon 6 ◽  
Polymer Fibers ◽  
Basic Design ◽  
Quenching Process ◽  
Pre Treatment ◽  
Selection Of

The project concentrates on the basic design of a cooling system for rapidly cooling nylon 6, 6 polymer fibers using cold air. The ambient air after pre-treatment in the air-washer is available at 72°F all year round. Based on the company’s throughput, it is required to supply (quench) air at 58°F. Nylon 6, 6 polymer after thorough polymerization is distributed through 16 quench cabinets and each quench cabinet requires approximately 530 ft3/min (cubic feet per minute, CFM) of air. The project concentrates on the basic design of a cooling system wherein air at the required mass flow rate is supplied at 58°F for the quenching process. A basic design of the refrigeration cycle and heat exchangers were considered in this work. In the development of the basic design for heat exchanger, performance charts were developed. Performance charts describe the performance of the heat exchanger in terms of fundamental dimensionless parameters. Using performance charts it was clearly seen that increasing the number of transfer units (NTU) doesn’t necessarily increase the rate of heat transfer. Increasing the NTU beyond an optimum value is pointless and increases the capital cost of the heat exchanger. The preliminary design involves selection of appropriate NTU and capacity rate ratio for the heat exchanger. From the capacity rate ratio and NTU, it is fairly straight forward to extrapolate the detailed design for the heat exchanger. A cooling system model was developed for the design process and for the simulation of the cooling system.  

Optimization and Active Control of the Underhood Cooling System: A Numerical Analysis

2010 ◽  
Author(s):  
Mahmoud Khaled ◽  
Fabien Harambat ◽  
Anthony Yammine ◽  
Hassan Peerhossaini
Keyword(s):  
Heat Exchanger ◽  
Numerical Analysis ◽  
Active Control ◽  
Heat Exchangers ◽  
Cooling System ◽  
Two Dimensional ◽  
System A ◽  
Computational Code ◽  
Cooling Module ◽  
Real Vehicle

Here numerical analysis is focused on optimizing the vehicle heat exchanger by varying the geometry in which it is integrated in the vehicle’s cooling system. This analysis also elucidates how one can affect the different parameters that influence heat exchanger performance in order to optimize their functioning, in relation to the geometry in which they are integrated. The two-dimensional computational code developed permits optimizing the performance of the cooling module by positioning different heat exchangers, in both driving and stop phases of the vehicle. The ultimate aim is to develop new approaches to controlling heat exchanger positions in a real vehicle cooling system.

Theoretical Study and Mathematical Modeling of Plate-Pin Fin Heat Exchanger for Solar Photovoltaic Cooling System

2014 ◽  
Vol 984-985 ◽  
pp. 1138-1146
Author(s):  
R. Vijaykumar ◽  
T. Mukesh ◽  
R. Rudramoorthy
Keyword(s):  
Heat Exchanger ◽  
Cooling System ◽  
Production Capacity ◽  
Climatic Conditions ◽  
Air Cooling ◽  
Solar Photovoltaic ◽  
Water Cooling ◽  
Solar Pv ◽  
Pv System ◽  
Pin Fin

Solar photovoltaic (PV) plays a major role in the renewable energy sector in the field of power production. Production of electricity from solar PV is gaining rapid importance due to its cleaner energy production capacity and it’s adaptability to various climatic conditions. PV cells suffer noticeable drop in efficiency as their operating temperature increases beyond a certain limit. In such cases cooling of the PV cells becomes mandatory. Since the efficiencies of PV cells are in the lower range (a maximum of 18%), a highly effective, inexpensive cooling system is necessary to be employed. Air cooling provides a solution to this cause and is meant to be an better counterpart to water cooling since it overcomes the problems of water cooling such as silt formation, evaporation, soiling and reflection losses. This paper presents a simple mathematical PV/T model to design the cooling system using plate-pin fin extended surface heat exchanger model. A relationship between the heat dissipated and the number of fins along with its dependence on individual fin area is also developed. This model will provide the researchers to design their cooling system according to their PV system geometry.

Analysis of Intercooler in PEM Fuel Cell Systems

Volume 3 ◽  
2004 ◽  
Author(s):  
Takamasa Ito ◽  
Jinliang Yuan ◽  
Bengt Sunde´n
Keyword(s):  
Heat Exchanger ◽  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Cooling System ◽  
Ambient Air ◽  
Proton Exchange ◽  
High Mass ◽  
Air Cooling ◽  
Cell Systems ◽  
Cold Stream

Heat exchangers are used in proton exchange membrane fuel cell systems (PEMFCs) for stack cooling, intercooling, water condensation and fuel reforming. Especially, the heat exchanger for the intercooling before the humidifier is investigated in this paper. It is found that, at high pressure or high mass flow rate, the need to cool the air (oxidant) is large. The heat exchanger uses coolant water from the stack cooling system or ambient air as the cold stream. With water-cooling, the volume of the heat exchanger will be small. However, difficulties exist because the small available temperature difference. Air-cooling can be used over a wide operating range but the heat exchanger volume will be large.

scholarly journals New LED lamp design with heat pipes

2019 ◽  
pp. 34-42 ◽  
Author(s):  
D. V. Pekur ◽  
Yu. E. Nikolaenko ◽  
V. M. Sorokin
Keyword(s):  
Heat Exchanger ◽  
Thermal Resistance ◽  
Light Source ◽  
Cooling System ◽  
Heat Pipes ◽  
Ambient Air ◽  
Light Sources ◽  
Heat Conducting ◽  
Led Light ◽  
Semiconductor Crystals

The problem of climate change poses a challenge for humanity: it is necessary to reduce harmful emissions into the atmosphere, caused mainly by the burning of coal in thermal power plants. Partially, this problem can be solved by the use of energy-saving devices and equipment, including the replacement of traditional light sources with more efficient LEDs. This, however, causes the problem of ensuring normal thermal modes of the LEDs, since the more powerfull the LED is, the more heat is released in their semiconductor crystals, which leads to an increase in the temperature of the crystals and a decrease in the reliability of the device. This problem becomes especially urgent when using powerful multi-chip LED light sources, the so-called SOB matrices, whose power even now exceeds 500 W. This article presents a new design of a powerful LED lamp for indoor illumination of rooms with low ceilings. The heat from the LED is transferred via heat pipes to the heat exchanger rings looped around the light source. The heat exchanger rings are cooled by the natural convection of the surrounding air (at an ambient air temperature of 20°C). Computer simulation allowed evaluating the ability of the proposed cooling system to provide a normal thermal mode of the LED light source. The results on the computer simulations of the temperature field of light source`s cooling system showed that when the LED power is 300 W, the temperature of the light source`s base at the point where it is connected to the light source does not exceed 67.6°C. When the contact zone is covered with a 0.1 mm layer of heat-conducting paste (Arctiс Silver 5 type) with a thermal conductivity coefficient of 8.7 W/(m•°C), the temperature of the LED case reaches 70°C. If the thermal resistance of the LED light source is 0.1°C/W, then the temperature of its semiconductor crystals will be 100°C, well below the allowable temperature value of 150°C. The total thermal resistance of the cooling system is 0.159°C/W.

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