scholarly journals Sloshing Motion in a Real-Scale Water Storage Tank under Nonlinear Ground Motion

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2098 ◽  
Author(s):  
Heng Jin ◽  
Ruiyin Song ◽  
Yi Liu
Keyword(s):  
Water Storage ◽  
Side Wall ◽  
Seismic Excitation ◽  
Seismic Excitations ◽  
Strong Earthquakes ◽  
Water Storage Tank ◽  
Time Histories ◽  
Water Tanks ◽  
Sloshing Pressure ◽  
Real Scale

Water storage tanks in cities are usually large and are occasionally affected by earthquakes. A sudden earthquake can cause pressure pulses that damage water containers severely. In this study, the sloshing motion in a high filling level tank caused by seismic excitation is investigated by the numerical method in a 2D model. Two well-studied strong earthquakes are used to analyze the broadband frequency nonlinear displacement of the tank both in the longitudinal and vertical directions. Based on careful experimental verification, the free surface motion and the elevations at the side wall are captured, and the sloshing pressure response is examined. The results show that the 2D section of the cylindrical tank can be used to estimate the maximum response of the 3D sloshing, and the water motions under the seismic excitations are consistent with the modal characteristics of the sloshing. The time histories response of the water motion reflected that the sloshing response is hysteretic compared with the seismic excitation. The anti-seismic ability of the damping baffle shows that its effect on sloshing pressure suppression is limited, and further study on the seismic design of water tanks in earthquake-prone regions is needed.

Seismic Response Reduction Caused by Coupling Between Beam-Type and Oval-Type Vibrations of a Cylindrical Water Storage Tank Under Large Excitation

2007 ◽  
Author(s):  
Akira Maekawa ◽  
Katsuhisa Fujita ◽  
Michiaki Suzuki
Keyword(s):  
Seismic Response ◽  
Water Storage ◽  
Degree Of Freedom ◽  
Seismic Excitation ◽  
System Model ◽  
Single Degree Of Freedom ◽  
Water Storage Tank ◽  
Single Degree ◽  
Input Acceleration ◽  
Beam Type

This study describes the response reduction caused by coupling between the beam-type and the oval-type vibrations of a cylindrical water storage tank under seismic excitation. In this study, the seismic response experiment is performed by using a 1/10 reduced scale model of an actual tank and then numerical simulation is performed by the simplified model. The authors conducted the sinusoidal response experiment for the tank and reported that the coupling between the beam-type and the oval-type vibrations causes the resonance frequency of the beam-type vibration to shift to the lower frequency and the response in the beam-type vibration (the response of the tank) to reduce. The seismic response experiment of the tank model filled with water up to 95% is performed by a shaking table. The El Centro 1940 NS and the improved standard seismic wave for Japanese LWR are used as the input seismic wave. The experimental results show that the maximum response acceleration does not enlarge linearly as the maximum input acceleration increases. The dominant resonance frequency slightly shifts to the lower frequency as the maximum input acceleration increases. It is concluded that the coupling between the beam-type and the oval-type vibrations make an influence on the beam-type vibration in seismic excitation. In the meantime, the authors propose the nonlinear single-degree-of-freedom system model to explain that the vibration response of the tank reduces. This model is based on geometric nonlinearity due to the out-of-plane deformation of the side-wall of the tank caused by the oval-type vibration. The numerical simulation of the seismic response is conducted using the nonlinear single-degree-of-freedom system model proposed by the authors. The analytical results agree with the experimental results as a general trend. Therefore, it is concluded that the response reduction of the tank is generated by coupling between the beam-type and the oval-type vibrations in the seismic excitation as well as the sinusoidal excitation. In addition, the response reduction rate of the tank under much larger seismic excitation can be estimated by using the nonlinear single-degree-of-freedom system model.

THE EFFECT OF UPPER-HEATING SYSTEM IN SOLAR WATER STORAGE TANK

2014 ◽  
Vol 22 (04) ◽  
pp. 1450027 ◽  
Author(s):  
HYO SEOK SON ◽  
JAE-WOOK KWON ◽  
SEONG HOON LEE ◽  
CHUL KIM ◽  
HIKI HONG
Keyword(s):  
Storage Tank ◽  
Thermal Stratification ◽  
Collection Efficiency ◽  
Water Storage ◽  
Side Wall ◽  
Heating System ◽  
Substantial Improvement ◽  
Solar Heating ◽  
Hot Water ◽  
Water Storage Tank

Thermal stratification in the water storage tank of solar heating system is essential to increase the collection efficiency. We previously investigated the stratification performance of side-heating system, where the hot water returning from the collector heats up the side wall of storage tank. Subsequently, we studied an evolved heating system for further improvement, where we added an upper-heating to the side-heating. Here we thoroughly examine the stratification performance of the evolved heating system using TRNSYS-based simulation. As the essential result, contrary to expectation, evolved system does not show substantial improvement of collection efficiency compared to side-heating. However, we confirm that evolved system excels in the useful energy.

scholarly journals A Study on the solar radiation incident upon the overhead water tanks in Saudi Arabia with different configurations

2018 ◽  
Vol 7 (3) ◽  
pp. 991 ◽  
Author(s):  
Hassan Khurshid ◽  
Karthik Silaipillayarputhur
Keyword(s):  
Saudi Arabia ◽  
Solar Radiation ◽  
Storage Tank ◽  
Residential Buildings ◽  
Water Storage ◽  
Solar Irradiation ◽  
Free Standing ◽  
Water Storage Tank ◽  
Glass Insulation ◽  
Water Tanks

Saudi Arabia is one of the warmer countries in the Middle East region. In the summer months, the ambient temperature reaches 50°C on regular basis. This high temperature has a direct effect on the elevation of water temperatures inside the domestic and commercial over-head tanks. The tanks are predominantly installed on the roof of the buildings without any shade or insulation and are exposed to the direct irradiation from the sun. The tank material is not capable of reducing the effect of solar radiation. Therefore, water gets very hot in the afternoon that it is impossible for the occupants of the residential buildings to take a shower or even wash their hands. This paper studied the effect of solar irradiation on the water temperature in the over-head storage water tanks during the summer months. The temperature rise in the water storage tank was considered for different cases, (i.e.) a free standing tank exposed to direct sun’s irradiation, a tank with shade, a tank with fiber glass insulation, and a tank having insulation along with shade. An analytical model was developed to study the effects of sun’s irradiation and the results were compared with that of experimentation. The results from the water storage tank having insulation exhibited encouraging results.  

Vibration Test of 1/10 Scale Model of Cylindrical Water Storage Tank

2004 ◽  
Author(s):  
Akira Maekawa ◽  
Yasutaka Shimizu ◽  
Michiaki Suzuki ◽  
Katsuhisa Fujita
Keyword(s):  
Storage Tank ◽  
Large Scale ◽  
Seismic Waves ◽  
Fluid Pressure ◽  
Water Storage ◽  
Seismic Excitation ◽  
Scale Model ◽  
Vibration Test ◽  
Water Storage Tank ◽  
Circumferential Distribution

Large-scale cylindrical water storage tanks have a large ratio of radius to thickness, which means their thickness is relatively thin compared with the radius. Regarding seismic responses, the deformation of a tank frame is significantly influenced by the sloshing of the water inside the tank and by the bulging vibration of the tank structure, therefore it is important to consider such deformation theoretically and experimentally. This paper describes the results of a vibration test with a 1/10 reduced scale model of a large-scale industrial cylindrical water storage tank, conducted particularly to clarify the dynamic behavior of the tank during a seismic excitation. First a sinusoidal wave excitation experiment was performed for the scale model tank, which measured axial distributions of dynamic fluid pressures, strains and accelerations. Ovaling vibration of the scale model tank also was examined by measuring the circumferential distribution of strains. Furthermore, the dependence of dynamic fluid pressure on the acceleration magnitude of the input excitation was investigated. Secondly, a seismic excitation experiment was conducted using typical seismic waves. Finally, the measuring results were compared with the values calculated using common seismic-proof design methods based on the Housner method or velocity potential theory and the finite element method. Considering the differences between the experiment values and numerical design ones, it became obvious that there was inconsistent between the positive and the negative pressures of the dynamic fluid pressure and that the dynamic fluid pressure was dependent on the acceleration magnitude. And it was suggested that such phenomena were caused by ovaling vibration. They, however, had little effect on the seismic-proof design of the tank in the range of acceleration used in this study.

Energy-saving analysis of air source heat pump integrated with a water storage tank for heating applications

2020 ◽  
Vol 180 ◽  
pp. 107029
Author(s):  
Pin Wu ◽  
Zhichao Wang ◽  
Xiaofeng Li ◽  
Zhaowei Xu ◽  
Yingxia Yang ◽  
...  
Keyword(s):  
Energy Saving ◽  
Heat Pump ◽  
Storage Tank ◽  
Water Storage ◽  
Water Storage Tank ◽  
Air Source Heat Pump

scholarly journals The effect of household storage tanks/vessels and user practices on the quality of water: a systematic review of literature

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Musa Manga ◽  
Timothy G. Ngobi ◽  
Lawrence Okeny ◽  
Pamela Acheng ◽  
Hidaya Namakula ◽  
...  
Keyword(s):  
Systematic Review ◽  
Water Quality ◽  
Storage Tank ◽  
Grey Literature ◽  
Water Storage ◽  
Storage Tanks ◽  
Water Storage Tank ◽  
Hygiene Practices ◽  
Quality Of Water ◽  
Vessel Material

Abstract Background Household water storage remains a necessity in many communities worldwide, especially in the developing countries. Water storage often using tanks/vessels is envisaged to be a source of water contamination, along with related user practices. Several studies have investigated this phenomenon, albeit in isolation. This study aimed at developing a systematic review, focusing on the impacts of water storage tank/vessel features and user practices on water quality. Methods Database searches for relevant peer-reviewed papers and grey literature were done. A systematic criterion was set for the selection of publications and after scrutinizing 1106 records, 24 were selected. These were further subjected to a quality appraisal, and data was extracted from them to complete the review. Results and discussion Microbiological and physicochemical parameters were the basis for measuring water quality in storage tanks or vessels. Water storage tank/vessel material and retention time had the highest effect on stored water quality along with age, colour, design, and location. Water storage tank/vessel cleaning and hygiene practices like tank/vessel covering were the user practices most investigated by researchers in the literature reviewed and they were seen to have an impact on stored water quality. Conclusions There is evidence in the literature that storage tanks/vessels, and user practices affect water quality. Little is known about the optimal tank/vessel cleaning frequency to ensure safe drinking water quality. More research is required to conclusively determine the best matrix of tank/vessel features and user practices to ensure good water quality.

scholarly journals Minimum Number of Experimental Data for the Thermal Characterization of a Hot Water Storage Tank

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4741
Author(s):  
María Gasque ◽  
Federico Ibáñez ◽  
Pablo González-Altozano
Keyword(s):  
Experimental Data ◽  
Water Temperature ◽  
Temperature Profile ◽  
Storage Tank ◽  
Water Storage ◽  
Hot Water ◽  
Experimental Temperature ◽  
Inlet Temperature ◽  
Water Storage Tank ◽  
Minimum Number

This paper demonstrates that it is possible to characterize the water temperature profile and its temporal trend in a hot water storage tank during the thermal charge process, using a minimum number of thermocouples (TC), with minor differences compared to experimental data. Four experimental tests (two types of inlet and two water flow rates) were conducted in a 950 L capacity tank. For each experimental test (with 12 TC), four models were developed using a decreasing number of TC (7, 4, 3 and 2, respectively). The results of the estimation of water temperature obtained with each of the four models were compared with those of a fifth model performed with 12 TC. All models were tested for constant inlet temperature. Very acceptable results were achieved (RMSE between 0.2065 °C and 0.8706 °C in models with 3 TC). The models were also useful to estimate the water temperature profile and the evolution of thermocline thickness even with only 3 TC (RMSE between 0.00247 °C and 0.00292 °C). A comparison with a CFD model was carried out to complete the study with very small differences between both approaches when applied to the estimation of the instantaneous temperature profile. The proposed methodology has proven to be very effective in estimating several of the temperature-based indices commonly employed to evaluate thermal stratification in water storage tanks, with only two or three experimental temperature data measurements. It can also be used as a complementary tool to other techniques such as the validation of numerical simulations or in cases where only a few experimental temperature values are available.

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