scholarly journals Evaluation of thermal performance for natural and forced draft wet cooling tower

2019 ◽  
Vol 13 (4) ◽  
pp. 6007-6021 ◽  
Author(s):  
M. J. Al-Dulaimi ◽  
F. A. Kareem ◽  
F. A. Hamad
Keyword(s):  
Flow Rate ◽  
Thermal Performance ◽  
Cooling Tower ◽  
Volume Flow Rate ◽  
Volume Flow ◽  
Experimental Results ◽  
Water Volume ◽  
Axial Fan ◽  
Natural Draft ◽  
Forced Draft

This paper presents an experimental and numerical investigation of the thermal performance of natural draft wet cooling tower (NDWCT). The experimental investigation is carried out under natural draft condition and forced draft condition created by an axial fan. The operational parameters considered in this study are the thickness of the fill (10 and 20 cm), inlet water temperature (40, 45, and 50 °C) and inlet water volume flow rate (5.68, 7.75, and 9.46 L/min). The experimental results showed that the thermal performance is improved when the fans are used with the NDWCT. The temperature difference between inlet and outlet and effectiveness increase by 35% and 37.2%, respectively at fill thickness of 20 cm and water volume flow rate of 11.35 L/min. The temperature distribution of the air and the relative humidity were numerically simulated for both cases of natural and forced draft by employing the commercial CFD software ANSYS Fluent 15. The experimental and numerical results were validated with results from a previous work and showed a good agreement. The experimental results showed that the effectiveness increase by 22% and 30% for NDWCT and FDWCT respectively when in case of fill thickness 20 cm.

scholarly journals Pengaruh sudut alur sekat terhadap unjuk kerja menara pendingin (cooling tower)

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
A. Ardani ◽  
I. Qiram ◽  
Gatut Rubiono
Keyword(s):  
Heat Transfer ◽  
Water Temperature ◽  
Heat Transfer Rate ◽  
Air Temperature ◽  
Flow Rate ◽  
Transfer Rate ◽  
Cooling Tower ◽  
Volume Flow Rate ◽  
Volume Flow ◽  
Water Volume

Cooling tower is an equipment that use to decrease water temperature by extracting heat and emitting it to atmosphere. Cooling tower buffle is an important component that effect water flow. This research is aimed to get the effect of cooling tower buffle due to its performance which are range, heat transfer rate and efficiency. The research is done by experiment. Cooling tower buffle are varied in plot angle which are 5o, 10o, 15o dan 20o. Water volume flow rate are varied as 50, 75, 100 and 125 ml/s. Inlet water tempersatur are varied as 50o, 60o and 70oC. The measurements are done for water and air temperature at inlet and outlet points. The result shows that buffle plot angle has effect due to cooling tower performance.

scholarly journals Pengaruh sudut alur sekat terhadap unjuk kerja menara pendingin (cooling tower)

2018 ◽  
Vol 8 (1) ◽  
pp. 21
Author(s):  
A. Ardani ◽  
I. Qiram ◽  
G. Rubiono
Keyword(s):  
Heat Transfer ◽  
Water Temperature ◽  
Heat Transfer Rate ◽  
Air Temperature ◽  
Flow Rate ◽  
Transfer Rate ◽  
Cooling Tower ◽  
Volume Flow Rate ◽  
Volume Flow ◽  
Water Volume

Cooling tower is an equipment that use to decrease water temperature by extracting heat and emitting it to atmosphere. Cooling tower buffle is an important component that effect water flow. This research is aimed to get the effect of cooling tower buffle due to its performance which are range, heat transfer rate and efficiency. The research is done by experiment. Cooling tower buffle are varied in plot angle which are 5o, 10o, 15o dan 20o. Water volume flow rate are varied as 50, 75, 100 and 125 ml/s. Inlet water tempersatur are varied as 50o, 60o and 70oC. The measurements are done for water and air temperature at inlet and outlet points. The result shows that buffle plot angle has effect due to cooling tower performance.

Thermal Performance Intensification of Car Radiator using SiO2/Water and ZnO/Water Nanofluids

2021 ◽  
pp. 1-25
Author(s):  
Hussein Maghrabie ◽  
Hamouda Mousa
Keyword(s):  
Heat Transfer ◽  
Working Conditions ◽  
Flow Rate ◽  
Thermal Performance ◽  
Cooling System ◽  
Volume Flow Rate ◽  
Volume Flow ◽  
Coolant Temperature ◽  
Inlet Temperature ◽  
The Impact

Abstract Recent progress in nanotechnology has lead to a revolution in the automotive cooling system. In the present work, enhancement of car radiator thermal performance was investigated using different nanofluids named SiO2/water, ZnO/water nanofluids as cooling mediums. The present study mainly aims to investigate the impact of (5 wt.%) from SiO2 and ZnO nanoparticles (NPs) dispersed in water based on car radiator heat transfer with spherical and hexagonal morphology, respectively. The experiments were performed in two working conditions of the nanofluids i.e coolant temperature and volume flow rate, moreover the present results were compared with the previous studies. The experimental working conditions were set at coolant inlet temperature (tc,i) ranged from 45 oC to 80 oC and the coolant volume flow rate (V) ranged from 3.5 lit/min to 6.5 lit/min. The experimental results show that the hexagonal ZnO/water nanofluid was superior towards enhancement of car radiator thermal performance comparing to that of SiO2 NPs. Additionally, at 6.5 lit/min and 45 °C, the enhancements of car radiator effectiveness due to using SiO2 and ZnO based water nanofluids and compared with that for the based water were 13.9% and 16%, respectively. The present study used the multiple regression analysis (MRA) and hence empirical correlations are suggested to estimate the overall heat transfer coefficient (U) for all coolants as functions of volume flow rate (V) and the coolant inlet temperature (tc,i) with a maximum STDEV of ± 1.85%.

scholarly journals Thermal Performance Analysis of the Charging/Discharging Process of a Shell and Horizontally Oriented Multi-Tube Latent Heat Storage System

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6193
Author(s):  
Mohamed Fadl ◽  
Philip Eames
Keyword(s):  
Latent Heat ◽  
Flow Rate ◽  
Thermal Performance ◽  
Thermal Energy ◽  
Volume Flow Rate ◽  
Storage System ◽  
Volume Flow ◽  
Hot Water ◽  
Working Fluid ◽  
Heat Demand

In this study, the thermal performance of latent heat thermal energy storage system (LHTESS) prototype to be used in a range of thermal systems (e.g., solar water heating systems, space heating/domestic hot water applications) is designed, fabricated, and experimentally investigated. The thermal store comprised a novel horizontally oriented multitube heat exchanger in a rectangular tank (forming the shell) filled with 37.8 kg of phase change material (PCM) RT62HC with water as the working fluid. The assessment of thermal performance during charging (melting) and discharging (solidification) was conducted under controlled several operational conditions comprising the heat transfer fluid (HTF) volume flow rates and inlet temperatures. The experimental investigations reported are focused on evaluating the transient PCM average temperature distribution at different heights within the storage unit, charging/discharging time, instantaneous transient charging/discharging power, and the total cumulative thermal energy stored/released. From the experimental results, it is noticed that both melting/solidification time significantly decreased with increase HTF volume flow rate and that changing the HTF inlet temperature shows large impacts on charging time compared to changing the HTF volume flow rate. During the discharging process, the maximum power output was initially 4.48 kW for HTF volume flow rate of 1.7 L/min, decreasing to 1.0 kW after 52.3 min with 2.67 kWh of heat delivered. Based on application heat demand characteristics, required power levels and heat demand can be fulfilled by employing several stores in parallel or series.

scholarly journals C INVESTIGATION OF HEAT TRANSFER COEFFICIENT AUGMENTATION IN DIVERGENT RECTANGULAR DUCT FOR TWO PHASES FLOW (AIR-WATER)

2020 ◽  
Vol 20 (2) ◽  
pp. 111-121
Author(s):  
Hadi O . Basher ◽  
Riyadh S Al-Turaihi ◽  
Ahmed A. Shubba
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Flow Rate ◽  
Volume Flow Rate ◽  
Volume Flow ◽  
Water Volume ◽  
Maximum Heat ◽  
Air Volume ◽  
The Heat Transfer Coefficient

In this project, the flow distribution for air and water, and the enhancement of the heattransfer coefficient are experimentally studied. Experimental studies have been performed totest the influence of discharge, pitch, the height of ribs at a constant heat flux on thetemperature and pressure distributions. Along the channel of the test and the heat transfercoefficient, the water volume flow rate was about (5-12 L/min), the air volume flow rate wasabout (5.83-16.66 L/min), and heat were (80, 100,120, watt). An experimental rig wasconstructed within the test whole system. On the other hands, the channel has a divergentsection with an angle =15o with vertical axis. The study included changing in the ribs heightby using three values (12, 15, 18 mm) and changing the ribs pitch into three values (5, 8, 10mm).The results indicated an increasing in the local heat transfer coefficient as a result ofincreasing the discharge. While there was an inverse influence for the temperature distributionalong the test channel which drops when the discharge rise. The results also confirm that theincreasing in the pitch distance leads to reduce the heat transfer coefficient. Increasing theribs height increases the coefficient of heat transfer. However, the experiment heat transfercoefficient improves about (15.6 %) when the water volume flow rate increased from (5 to 12L/min), and about (18.7%) when the air volume flow rate increased from (5.83 to 16.66L/min). The best heat transfer coefficient was about (35.6 %) which can be achieved whenthe pitch decreased from (10 to 5mm). The increasing of the height from (12 to 18) mmimproves the heat transfer coefficient about (11.2 %). The best rib dimension was 18 mmheight, and 5 mm pitch, which give a maximum heat transfer coefficient (1212.02 W/m2. oC).

Impact of Structure Design of Artififical Upwelling Tube

2014 ◽  
Vol 496-500 ◽  
pp. 547-550 ◽  
Author(s):  
Jin Ying Leng ◽  
Jia Wang Chen ◽  
Hao Cai Huang ◽  
Shan Lin ◽  
Ming Zhou Liu ◽  
...  
Keyword(s):  
Flow Rate ◽  
Volume Flow Rate ◽  
Free Water ◽  
Deep Ocean ◽  
Structure Design ◽  
Volume Flow ◽  
Water Volume ◽  
Nutrient Distribution ◽  
Surrounding Water ◽  
Deep Ocean Water

Deep ocean water (DOW) is cold, nutrient-rich and pathogen-free water, which can be transported to the surface by upwelling. Upwelling can change the temperature and nutrient distribution of the surrounding water, hence improves the marine ecological environment and the marine primary productivity. Two lake experiments were accomplished in Qiandao Lake .The first experiment was done with hard PVC upwelling tube, while in the second experiment , the upwelling tubes with different diameters (0.5 m, 1 m, 1.5 m and 2 m) were made of nylon ,which are supported by rings. It can be concluded that upwelling ratio (the ratio of water volume flow rate and air volume flow rate) of the hard PVC upwelling tube was higher than that of soft nylon upwelling tube, and in condition of soft nylon upwelling tube, upwelling ratio of 1 m diameter tube was higher than that of others, providing important guidance for the next sea trial.

Novel epoxy/anhydride alternatives for biological electron microscopy: Physical and performance characteristis of embed 812 and LX 112 in combination with NSA/NMA/DMAE

1989 ◽  
Vol 47 ◽  
pp. 1000-1001
Author(s):  
Joe A. Mascorro ◽  
Gerald S. Kirby
Keyword(s):  
Electron Microscopy ◽  
Flow Rate ◽  
Succinic Anhydride ◽  
Volume Flow Rate ◽  
Mass Density ◽  
Uranyl Acetate ◽  
Volume Flow ◽  
Base Resin ◽  
And Performance ◽  
Acid Anhydrides

Embedding media based upon an epoxy resin of choice and the acid anhydrides dodecenyl succinic anhydride (DDSA), nadic methyl anhydride (NMA), and catalyzed by the tertiary amine 2,4,6-Tri(dimethylaminomethyl) phenol (DMP-30) are widely used in biological electron microscopy. These media possess a viscosity character that can impair tissue infiltration, particularly if original Epon 812 is utilized as the base resin. Other resins that are considerably less viscous than Epon 812 now are available as replacements. Likewise, nonenyl succinic anhydride (NSA) and dimethylaminoethanol (DMAE) are more fluid than their counterparts DDSA and DMP- 30 commonly used in earlier formulations. This work utilizes novel epoxy and anhydride combinations in order to produce embedding media with desirable flow rate and viscosity parameters that, in turn, would allow the medium to optimally infiltrate tissues. Specifically, embeding media based on EmBed 812 or LX 112 with NSA (in place of DDSA) and DMAE (replacing DMP-30), with NMA remaining constant, are formulated and offered as alternatives for routine biological work.Individual epoxy resins (Table I) or complete embedding media (Tables II-III) were tested for flow rate and viscosity. The novel media were further examined for their ability to infilftrate tissues, polymerize, sectioning and staining character, as well as strength and stability to the electron beam and column vacuum. For physical comparisons, a volume (9 ml) of either resin or media was aspirated into a capillary viscocimeter oriented vertically. The material was then allowed to flow out freely under the influence of gravity and the flow time necessary for the volume to exit was recored (Col B,C; Tables). In addition, the volume flow rate (ml flowing/second; Col D, Tables) was measured. Viscosity (n) could then be determined by using the Hagen-Poiseville relation for laminar flow, n = c.p/Q, where c = a geometric constant from an instrument calibration with water, p = mass density, and Q = volume flow rate. Mass weight and density of the materials were determined as well (Col F,G; Tables). Infiltration schedules utilized were short (1/2 hr 1:1, 3 hrs full resin), intermediate (1/2 hr 1:1, 6 hrs full resin) , or long (1/2 hr 1:1, 6 hrs full resin) in total time. Polymerization schedules ranging from 15 hrs (overnight) through 24, 36, or 48 hrs were tested. Sections demonstrating gold interference colors were collected on unsupported 200- 300 mesh grids and stained sequentially with uranyl acetate and lead citrate.

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