scholarly journals Experimental Investigation on Chemical Grouting in a Permeated Fracture Replica with Different Roughness

2019 ◽  
Vol 9 (13) ◽  
pp. 2762 ◽  
Author(s):  
Lichuang Jin ◽  
Wanghua Sui ◽  
Jialu Xiong
Keyword(s):  
Experimental Investigation ◽  
Water Flow ◽  
Flow Rate ◽  
Orthogonal Experiment ◽  
Water Flow Rate ◽  
Flowing Water ◽  
Gel Time ◽  
Initial Water ◽  
Chemical Grouting ◽  
Fracture Opening

This paper presents an experimental investigation on chemical grouting in a permeated fracture replica considering its roughness. Tests of grouting with flowing water in the fracture replica were carried out under different Bardon’s standard roughness profiles. The interactions between influential factors were considered and an experimental platform for grouting in rough fractures with flowing water was established. The effect of chemical grouting in fractures with flowing water was investigated using orthogonal experiment. The joint roughness coefficient (JRC), the initial water flow rate, the gel time, and the fracture opening were selected as factors in the orthogonal experiment. The results show that there is a positive correlation between the water plugging rate and JRC, and negative correlations between the water plugging rate and the initial water flow rate, gel time, and fracture opening. The change curve of the water flow rate is divided into three categories: Single platform decreasing type, double platform decreasing type, and multi-peak fluctuating type. The curve of seepage pressure contains three categories: Single peak type, multi-peak type and platform type. The results provide a reference for grouting in rock fractures.

scholarly journals An experimental investigation on the coefficient of performance of the small hot water heat pump using refrigeration R410A and R32

2020 ◽  
Vol 3 (2) ◽  
pp. First
Author(s):  
Le Minh Nhut ◽  
Tran Quang Danh
Keyword(s):  
Ambient Temperature ◽  
Water Temperature ◽  
Water Flow ◽  
Heat Pump ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Electric Heater ◽  
Initial Water

Hot water is an important factor in domestic life and industrial development. Today, the heat pump is used to produce hot water more and more popular because it has many advantages of saving energy compared to the method of producing hot water by the hot water electric heater. The main aim of this study is to evaluate of the coefficient of performance (COP) of the small hot water heat pump using refrigeration R410A and R32. The capacity of both hot water heat pump is similar, one using new refrigerant R32 and other using refrigerant R410A. These heat pumps were designed and installed at the Ho Chi Minh City University of Technology and Education to evaluate the COP for the purpose of application the new refrigerant R32 for hot water heat pump. The compressor capacity is 1 Hp, the volume of hot water storage tank is of 100 liters and is insulated with thickness of 30 mm to reduce the heat loss to invironment, the required hot water temperature at the outlet of condenser is 50 oC, and the amount of required hot water is 75 liters per batch and is controlled by float valve. The experimental results indicate that the COP of the heat pump using the new refrigerant R32 is higher than heat pump using refrigerant R410A from 9% to 15% when the experimental conditions such as ambient temperature, initial water flow rate through the condenser and the required temperature of hot water were the same. In addition, the effect of the ambient temperature, initial water temperature and water flow rate were also evaluated.

scholarly journals Experimental Analysis on the Effect of Area of Surface Cooling for a Water-Cooled Photovoltaic

2018 ◽  
Vol 225 ◽  
pp. 01011 ◽  
Author(s):  
Firdaus Basrawi ◽  
Yeong C. Leon ◽  
Thamir K. Ibrahim ◽  
Mohd Hazwan Yusof ◽  
A.A. Razak ◽  
...  
Keyword(s):  
Surface Area ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Effect Of Temperature ◽  
Maximum Temperature ◽  
Flowing Water ◽  
Surface Cooling ◽  
Cooling Surface ◽  
Power Outputs

Water flow for a water-cooled Photovoltaic (PV) may not cover the whole surface area of PV. Thus, the objective of this paper is to experimentally observe the effect of cooling surface area for a water-cooled PV. A water-cooled PV with 30W output was tested when its surface area was 50% and 100% covered with flowing water. This condition was tested at water flow rate of 120 mL/h, and irradiace of 855 W/m2, respectively. It was found that the panel recorded a maximum temperature of 72.10°C when it is uncooled. When it is cooled temperature decreased 22.05% and 51.04% for half and full surface, respectively, and temperature also remained constant approximately at 32oC for full surface. The current remained constant as expected and effect of temperature could be seen in voltage. Voltage increases when temperate decreases, and decreases when temperature increases. As the results, the power outputs for uncooled, half surface, and full surface were 10.38W, 10.66W and 11.08W, respectively. As compared to uncooled, this shows the increment of 6.10% and 13.50% for half surface and full surface, respectively. Thus, it could be concluded that the cooling surface area has substantial effects on the performance of water-cooled PV.

scholarly journals Effect of Water Flow on Underwater Wet Welded A36 Steel

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 682
Author(s):  
Eko Surojo ◽  
Aziz Harya Gumilang ◽  
Triyono Triyono ◽  
Aditya Rio Prabowo ◽  
Eko Prasetya Budiana ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Physical And Mechanical Properties ◽  
Shielded Metal Arc Welding ◽  
Effect Of Water ◽  
Bending Effect ◽  
Metal Arc Welding ◽  
A36 Steel

Underwater wet welding (UWW) combined with the shielded metal arc welding (SMAW) method has proven to be an effective way of permanently joining metals that can be performed in water. This research was conducted to determine the effect of water flow rate on the physical and mechanical properties (tensile, hardness, toughness, and bending effect) of underwater welded bead on A36 steel plate. The control variables used were a welding speed of 4 mm/s, a current of 120 A, electrode E7018 with a diameter of 4 mm, and freshwater. The results show that variations in water flow affected defects, microstructure, and mechanical properties of underwater welds. These defects include spatter, porosity, and undercut, which occur in all underwater welding results. The presence of flow and an increased flow rate causes differences in the microstructure, increased porosity on the weld metal, and undercut on the UWW specimen. An increase in water flow rate causes the acicular ferrite microstructure to appear greater, and the heat-affected zone (HAZ) will form finer grains. The best mechanical properties are achieved by welding with the highest flow rate, with a tensile strength of 534.1 MPa, 3.6% elongation, a Vickers microhardness in the HAZ area of 424 HV, and an impact strength of 1.47 J/mm2.

Experimental Characterization of a Modified Airlift Pump

2014 ◽  
Author(s):  
Afshin Goharzadeh ◽  
Keegan Fernandes
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
High Speed ◽  
Water Flow Rate ◽  
High Speed Photography ◽  
Two Phase ◽  
Inner Diameter ◽  
Airlift Pump ◽  
Flow Map ◽  
Churn Flow

This paper presents an experimental investigation on a modified airlift pump. Experiments were undertaken as a function of air-water flow rate for two submergence ratios (ε=0.58 and 0.74), and two different riser geometries (i) straight pipe with a constant inner diameter of 19 mm and (ii) enlarged pipe with a sudden expanded diameter of 19 to 32 mm. These transparent vertical pipes, of 1 m length, were submerged in a transparent rectangular tank (0.45×0.45×1.1 m3). The compressed air was injected into the vertical pipe to lift the water from the reservoir. The flow map regime is established for both configurations and compared with previous studies. The two phase air-water flow structure at the expansion region is experimentally characterized. Pipeline geometry is found to have a significant influence on the output water flow rate. Using high speed photography and electrical conductivity probes, new flow regimes, such as “slug to churn” and “annular to churn” flow, are observed and their influence on the output water flow rate and efficiency are discussed. These experimental results provide fundamental insights into the physics of modified airlift pump.

scholarly journals Impacts of Water Flow Rate on Freezing Prevention of Air-Cooled Heat Exchangers in Power Plants

Energies ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 112 ◽  
Author(s):  
Yonghong Guo ◽  
Huimin Wei ◽  
Xiaoru Yang ◽  
Weijia Wang ◽  
Xiaoze Du ◽  
...  
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Power Plants ◽  
Water Flow Rate

scholarly journals Experimental Investigation on Improvement of Wet Cooling Tower Efficiency with Diverse Packing Compaction Using ANN-PSO Algorithm

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 167
Author(s):  
Hasan Alimoradi ◽  
Madjid Soltani ◽  
Pooriya Shahali ◽  
Farshad Moradi Kashkooli ◽  
Razieh Larizadeh ◽  
...  
Keyword(s):  
Neural Network ◽  
Water Temperature ◽  
Water Flow ◽  
Flow Rate ◽  
Cooling Tower ◽  
Air Flow ◽  
Water Flow Rate ◽  
Pso Algorithm ◽  
Outlet Temperature ◽  
Air Flow Rate

In this study, a numerical and empirical scheme for increasing cooling tower performance is developed by combining the particle swarm optimization (PSO) algorithm with a neural network and considering the packing’s compaction as an effective factor for higher accuracies. An experimental setup is used to analyze the effects of packing compaction on the performance. The neural network is optimized by the PSO algorithm in order to predict the precise temperature difference, efficiency, and outlet temperature, which are functions of air flow rate, water flow rate, inlet water temperature, inlet air temperature, inlet air relative humidity, and packing compaction. The effects of water flow rate, air flow rate, inlet water temperature, and packing compaction on the performance are examined. A new empirical model for the cooling tower performance and efficiency is also developed. Finally, the optimized performance conditions of the cooling tower are obtained by the presented correlations. The results reveal that cooling tower efficiency is increased by increasing the air flow rate, water flow rate, and packing compaction.

Optimizing the performance of hemispheric solar still using nano-ZnO with cooling the glassy cover at a variable water flow rate

2021 ◽  
Author(s):  
Mohammed El Hadi Attia ◽  
Abd Elnaby Kabeel ◽  
S. A. El-Agouz ◽  
El Mir Mabrouk Lassaad ◽  
Ravishankar Sathyamurthy ◽  
...  
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Solar Still ◽  
Nano Zno ◽  
Variable Water
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