scholarly journals Basics of Calculation and Design of Two-Column Two-Filter Water Intake Wells

2021 ◽  
Vol 20 (5) ◽  
pp. 410-419
Author(s):  
V. V. Ivashechkin ◽  
J. A. Medvedeva ◽  
A. N. Kondratovich ◽  
E. S. Satsuta

The paper provides an overview of the known designs of water wells. A new design of a two-column two-filter water intake well has been also proposed, in which the filters are arranged in two tiers. This will lead to an increase in water intake capacity and will reduce the filtration rate on the approach to the filters. This, in turn, will create conditions for reducing head losses and will make it possible to reduce drawdowns in the well, ensuring a reduction in the cost of produced water. This design combines both working and reserve wells located in one borehole, which increases its reliability, durability and uninterrupted water supply to the consumer. A method for calculating the hydraulic parameters of a two-column two-filter water intake well is presented in the paper. It is based on dependencies for calculating the main geometric dimensions for a given design flow rate and hydrogeological characteristics of an aquifer, as well as formulas for determining a decrease in a well for a given period of operation when one and two pumps operate simultaneously. The basics of designing a well of the proposed design are outlined in the paper. The paper considers an example of calculation for a new well design instead of an existing typical well that has reduced its specific flow rate.

2019 ◽  
Vol 110 ◽  
pp. 01072 ◽  
Author(s):  
Vladimir Shcherbakov ◽  
Aleksandr Akulshin ◽  
Aleksandr Bachmetev ◽  
Anatolyi Akulshin

The paper is devoted to the problem of optimal design, construction and operation of water supply systems and their elements. The key element of the system is a water well. The quality of its design and construction determines the operation of the water intake as a whole. Disadvantages in the construction of a well lead to disruption of the entire water supply system of a particular object. The paper proposed a methodology for selecting the optimal diameter and length of the well filter of a water well. Based on the methodology, an example of filter parameters selection for hydrogeological conditions of the city of Kursk is given. The above calculation showed that the use of the entrance velocity criterion in the design of wells can significantly reduce the cost of well construction while ensuring the design flow rate and allowable lowering of the water level. The cost of the filter, depending on the well design, is 20-30% of the total price for its construction. The most important filter parameters affecting the cost of a well are its length and diameter. Justifying the minimum diameter of the filter that ensures the designed water intake and allowable dewatering can significantly reduce the cost of the well, taking into account the fact that modern pumping equipment allows the use of columns of small diameter above the filter.


2019 ◽  
Vol 22 (6) ◽  
pp. 40-50
Author(s):  
V. V. Bredikhin ◽  
A. A. Akulshin ◽  
K. I. Los

The example of judicial construction and technical examination of the constructed water intake well in one of settlements is considered in this article. The analysis of failures occurred during the operation of the newly built water intake well was carried out. The point moments on the quality and timing of the work performed there are often disputable when putting objects into operation. If these questions cannot be resolved by mutual agreement of the parties, their decision is transferred to the courts, which appoint judicial construction and technical expertise. The type of judicial engineering and technical expertise, judicial construction and technical expertise plays an important and sometimes decisive role in legal proceedings, including the consideration of civil disputes in courts of General jurisdiction and arbitration courts. Judicial construction and technical expertise was appointed on the basis of the decision of the arbitration court for a new water intake well built in one of the settlements of the Kursk region. The reason for the appointment of the examination is that this well has ceased to provide the planned flow rate, and the produced water meet the quality requirements. Two main reasons led to the decline in the technological characteristics of the well and the deterioration of the quality of the produced water: the wrong choice of the pumping unit and the lack of a water tower on the network. The selected ECV 6-16-140 pump created excess pressure in the network, which was then reduced by the installed automation (frequency Converter), and accordingly the well flow rate decreased. The use of frequency converters is not always useful, but can even have a harmful effect on the operation of the water supply system. In addition to reducing the flow rate, the operation of the frequency Converter caused the combustion of several pumps operating in unacceptable modes. The work of the frequency Converter installed on the pump unit with overestimated characteristics led to the turbidity of the produced water, there was an uneven consumption of water from the well.


Author(s):  
Kalyan K. Niyogi ◽  
Stefan Anton ◽  
Debabrata Mitra-Majumdar

A multistage orifice assembly is often used in fluid systems in nuclear plants in order to achieve a specific flow rate for a large pressure drop. Such an assembly is usually designed with a number of orifices installed in series. Apart from the performance parameters, an important design consideration is to guarantee absence of potential for cavitation inside the assembly. An improperly designed multistage orifice assembly may create cavitation at the outlet of some stages of the assembly when the pressure at the vena contracta reaches a pressure close to the vapor pressure of the fluid at the operating temperature. The cavitation condition makes not only the operation noisy but also results in a significant reduction of equipment life. It is a challenge to the designer to select a set of orifices so that the cavitation condition is simultaneously met at all stages of the assembly. On the other hand, it is also a challenge to design each individual orifice in the assembly so that its influence to the next orifice is minimal. These challenges have been met in design of a replacement multistage orifice design for the centrifugal charging pump mini-flow line of a nuclear plant for a pressure drop of 2,595 psi (17.89 MPa) at 60 gpm (227 l/min) flow-rate. The orifice assembly has eleven stages accommodated within a pipe of 24 inches (600 mm) length, and each stage consists of a 3-dimensional compound orifice. The fluid analysis is performed using the CFD code FLUENT/UNS. The code numerically solves the Navier-Stokes equations of fluid motion to obtain the velocity field and pressure distribution within a modeled 2- and 3-dimensional geometry. Turbulence effects are modeled by relating time-varying Reynolds stresses to the mean bulk flow quantities using the standard k-epsilon model. The design was optimized by fine tuning the geometric parameters of the orifice units to minimize the potential for cavitation and at the same time maintaining a high accuracy in the flow-rate. The full-scale prototype was successfully tested to confirm the performance. Actual flows in the prototype tests were observed to be within a fraction of a gpm of the design flow-rate and pressure drop. After orifice assembly was installed in the plant system, there was absolutely no operating noise, as opposed to the original unit that was extremely noisy. A number of other multistage orifice assemblies have subsequently been designed for different power plants using similar computational technique with great success.


2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Delia Teresa Sponza ◽  
Cansu Doğanx

The scope of this study, is  1-butanol production from CO2 with S. elongatus PCC 7942 culture. The yields of 1-butanolproduced/CO2utilized have been calculated. The maximum concentration of produced 1- butanol is 35.37 mg/L and 1-butanolproduced/CO2utilized efficiency is 92.4. The optimum operational conditions were  30°C temperature, 60 W intensity of light, pH= 7.1, 120 mV redox potential, 0.083 m3/sn flow rate with CO2 and 0.5 mg/l dissolved O2 concentration. Among the enzymes on the metabolic trail of the production of 1-butanol via using S. elongatus PCC 7942 cyanobacteria. At maximum yield; the measured concentrations are 0.016 µg/ml for hbd; 0.0022 µg/ml for Ter and 0.0048 µg/ml for AdhE2. The cost analyses necessary for 1-butanol production has been done and the cost of 1 litre 1-butanol has been determined as maximum 1.31 TL/L.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4566
Author(s):  
Minsoo Choi ◽  
Wongwan Jung ◽  
Sanghyuk Lee ◽  
Taehwan Joung ◽  
Daejun Chang

This study analyzes the thermodynamic, economic, and regulatory aspects of boil-off hydrogen (BOH) in liquid hydrogen (LH2) carriers that can be re-liquefied using a proposed re-liquefaction system or used as fuel in a fuel cell stack. Five LH2 carriers sailing between two designated ports are considered in a case study. The specific energy consumption of the proposed re-liquefaction system varies from 8.22 to 10.80 kWh/kg as the re-liquefaction-to-generation fraction (R/G fraction) is varied. The economic evaluation results show that the cost of re-liquefaction decreases as the re-liquefied flow rate increases and converges to 1.5 $/kg at an adequately large flow rate. Three energy efficient design index (EEDI) candidates are proposed to determine feasible R/G fractions: an EEDI equivalent to that of LNG carriers, an EEDI that considers the energy density of LH2, and no EEDI restrictions. The first EEDI candidate is so strict that the majority of the BOH should be used as fuel. In the case of the second EEDI candidate, the permittable R/G fraction is between 25% and 33%. If the EEDI is not applied for LH2 carriers, as in the third candidate, the specific life-cycle cost decreases to 67% compared with the first EEDI regulation.


2001 ◽  
Vol 7 (3) ◽  
pp. 173-181
Author(s):  
Tong-Miin Liou ◽  
Meng-Yu Chen

Laser-Doppler velocimetry (LDV) measurements are presented of relative mean velocity and turbulence intensity components inside the impeller passage of a centrifugal fan with twelve backward curved blades at design, under-design, and over-design flow rates. Additional LDV measurements were also performed at the volute outlet to examine the uniformity of the outlet flow for the three selected flow rates. Complementary flow visualization results in the tongue region are further presented. It is found that the number of characteristic flow regions and the average turbulence level increase with decreasing air flow rate. For the case of under-design flow rate, there are a through-flow region on the suction side, a reverse flow region on the pressure side, and a shear layer region in between. The corresponding average turbulence intensity is as high as 9.1% of blade tip velocity.


Author(s):  
Hucan Hou ◽  
Yongxue Zhang ◽  
Zhenlin Li ◽  
Xin Zhou ◽  
Zizhe Wang

In order to effectively improve hydraulic performance of centrifugal pump on off-conditions, the hydraulic design of inlet guide vane (IGV) was completed by adopting two dimensional theory in-house code based on one kind of IS series of centrifugal pump, which can achieve pre-whirl regulation of centrifugal pump. During design process the trailing edge of vane is assumed as equal velocity moment condition, and the distribution of vane setting angle along meridional streamline is also given as a quartic function firstly, the camber line is then drawn by point-by-point integration method and thickened at both sides along circumferential direction. With local vortex dynamics diagnosis theory, the optimal improvement of vane space shape can be finished by adjusting the design parameters of vane setting angle distribution coefficient ap. The full flow passage numerical simulations of centrifugal pump with IGV device are completed to analyze the influence of pre-whirl regulation on hydraulic performance of centrifugal pump under various pre-whirl angles. The results show that the pre-whirl regulation can improve the hydraulic performance of centrifugal pump on off-conditions. Under the positive pre-whirl regulation conditions, the best efficient point shift to small flow rate zone, and under the negative pre-whirl regulation conditions it moves to large flow rate zone. Compared with the pump without IGV device at the same flow rate condition of 0.8Q (Q the design flow rate), the hydraulic efficiency of centrifugal pump with IGV device improves obviously and reaches up to 1.43%. Meanwhile compared with that installed with the straight vanes designed based on the traditional theory, the inner flow field of centrifugal pump with the designed vanes improves and the overall hydraulic efficiency of centrifugal pump is somewhat increased.


2006 ◽  
Vol 290 (2) ◽  
pp. H894-H903 ◽  
Author(s):  
Ghassan S. Kassab

The branching pattern and vascular geometry of biological tree structure are complex. Here we show that the design of all vascular trees for which there exist morphometric data in the literature (e.g., coronary, pulmonary; vessels of various skeletal muscles, mesentery, omentum, and conjunctiva) obeys a set of scaling laws that are based on the hypothesis that the cost of construction of the tree structure and operation of fluid conduction is minimized. The laws consist of scaling relationships between 1) length and vascular volume of the tree, 2) lumen diameter and blood flow rate in each branch, and 3) diameter and length of vessel branches. The exponent of the diameter-flow rate relation is not necessarily equal to 3.0 as required by Murray's law but depends on the ratio of metabolic to viscous power dissipation of the tree of interest. The major significance of the present analysis is to show that the design of various vascular trees of different organs and species can be deduced on the basis of the minimum energy hypothesis and conservation of energy under steady-state conditions. The present study reveals the similarity of nature's scaling laws that dictate the design of various vascular trees and the underlying physical and physiological principles.


2010 ◽  
Vol 61 (3) ◽  
pp. 599-606 ◽  
Author(s):  
Johnsely S. Cyrus ◽  
G. B. Reddy

Constructed wetland systems have gained attention as attractive solutions for wastewater treatment. Wetlands are not efficient to treat wastewater with high concentrations of phosphorus (P). In order to remove high soluble P loads by wetland, sorbent beds can be added prior to the discharge of wastewater into wetlands. Sorption by sorbent materials is identified as a method for trapping excess P in wastewaters. In the present investigation, shale has been identified as a sorbent material for removal of phosphate (PO4-P) due to the cost effectiveness, stability and possibility of regeneration. The study focuses on the removal of PO4-P from wastewater using shale and the feasibility of using the P-sorbed material as slow-release fertilizer. Phosphorus sorption experiments were conducted by using shale (2 mm and 2–4.7 mm). Results indicate that Shale I (particle size = 2 mm) showed the highest sorption of PO4-P (500 ± 44 mg kg−1). Breakthrough point was reached within 10 h in columns with flow rates of 2 and 3 ml min−1. Lower flow rate of 1 ml min−1 showed an average residence time of about 2 h while columns with a higher flow rate of 3 ml min−1 showed a residence time of about 40 minutes. Variation in flow rate did not influence the desorption process. Since very low concentrations of PO4-P are released, Shale saturated with PO4-P may be used as a slow nutrient release source of P or as a soil amendment. The sorbent can also be regenerated by removing the sorbed PO4-P by using 0.1 N HCl.


1996 ◽  
Author(s):  
Steven L. Puterbaugh ◽  
William W. Copenhaver ◽  
Chunill Hah ◽  
Arthur J. Wennerstrom

An analysis of the effectiveness of a three-dimensional shock loss model used in transonic compressor rotor design is presented. The model was used during the design of an aft-swept, transonic compressor rotor. The demonstrated performance of the swept rotor, in combination with numerical results, is used to determine the strengths and weaknesses of the model. The numerical results were obtained from a fully three-dimensional Navier-Stokes solver. The shock loss model was developed to account for the benefit gained with three-dimensional shock sweep. Comparisons with the experimental and numerical results demonstrated that shock loss reductions predicted by the model due to the swept shock induced by the swept leading edge of the rotor were exceeded. However, near the tip the loss model under-predicts the loss because the shock geometry assumed by the model remains swept in this region while the numerical results show a more normal shock orientation. The design methods and the demonstrated performance of the swept rotor is also presented. Comparisons are made between the design intent and measured performance parameters. The aft-swept rotor was designed using an inviscid axisymmetric streamline curvature design system utilizing arbitrary airfoil blading geometry. The design goal specific flow rate was 214.7 kg/sec/m2 (43.98 lbm/sec/ft2), the design pressure ratio goal was 2.042, and the predicted design point efficiency was 94.0. The rotor tip sped was 457.2 m/sec (1500 ft/sec). The design flow rate was achieved while the pressure ratio fell short by 0.07. Efficiency was 3 points below prediction, though at a very high 91 percent. At this operating condition the stall margin was 11 percent.


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