Water Flow Control Research Articles

Construction of Flow Control Structures as an Essential Condition for Increasing the Efficiency of Hydropower Facilities in Mountainous Regions

The hydropower industry of the Kabardino-Balkarian Republic (KBR) is weakened by the absence of flow control structures. Due to the extremely weak flow control of the mountain rivers utilized by hydropower structures, the total production and economic effect of the operating power units is rather low. This circumstance determines the highest seasonal variability of the annual flow — compared to summer months, the capacity of power plants is reduced in winter by almost 5–6 times. It is obvious that it is almost impossible to utilize the entire capacity of river flows. At the same time, it is unacceptable when no more than 20% of the flow capacity is actually used, which leads to extremely low efficiency of expensive power units. The objective of this research is to study the engineering and economical feasibility of controlling the flow of mountain rivers of KBR, to study the possibility of creating an optimal water pressure by constructing water storage facilities, to assess mountain-valley landscapes and select specific cross-sections for the construction of priority flow control facilities. To achieve this objective, the following tasks were solved: - study the conditions of water flow control for glacier-fed mountain rivers; - formulate preliminary flow control schemes within the selected cross-sections; - assess natural properties of watercourses and their relevance for the construction of flow control facilities; search high-mountain lakes suitable for river flow accumulation in the first approximation; - substantiate a suitable sequence of construction of flow control facilities; - assess the approaches to seasonal and long-term water flow rate forecasting as an essential condition for optimizing the operation of hydropower units.

An evapotranspiration model driven by remote sensing data for assessing groundwater resource in karst watershed

Aquifer recharge may depend mainly on the difference between precipitation and evapotranspiration. Hydrological models used to estimate groundwater reserves use evapotranspiration models that are mainly determined by climate demand. In particular, mechanisms of plant transpiration are neglected, although transpiration constitutes 70% of evapotranspiration. This is problematic when considering karst watershed, which are poorly documented at the interface between soil and atmosphere where vegetation and soil properties control water flows. To fill this gap, we propose an evapotranspiration model that integrates the processes of plant transpiration and soil evaporation. The dynamics of vegetation is evaluated using the Enhanced Vegetation Indexes from the Terra and Aqua Moderate Resolution Imaging Spectroradiometers. The soil evaporation calculation account for the impact of coarse elements at soil surface. The “Simple Crop coefficient for Evapotranspiration” (SimpKcET) model is tested at flux tower sites over forest of Font-Blanche, Puechabon and the agricultural area of Avignon. The simulated daily evapotranspirations are very close to the observations (RMSE ~0.5 mm.d-1), while the model is simple compared to other models proposed in the literature. The SimpKcET is implemented in a karst hydrological model to evaluate the impact of evapotranspiration estimation on the aquifer flow rate simulation. This approach is applied to the vast watershed of Fontaine de Vaucluse. In comparison to the water bucket model that is frequently used in karst models, SimpKcET provide ET simulations that are more in line with ET processes. A cross wavelet analysis highlighted the improvement of the simulated recharge and observed flow rate relationship brought by the consideration of evaporation and transpiration processes. The use of remote sensing data related to plant activity makes it possible to propose a parsimonious model that can be applied to all types of vegetation (agricultural, natural, mixed forest) and that can be transferred to other karst models.

Study of fouling communities succession under conditions of the device of controlled water flow

For testing the anticorrosive and antifouling protective coatings, a ground stand is developed: the device of controlled water flow. The relevance of the study is undeniable, given the practical significance of the problem. The stand is connected to the main of sea running water. The device makes it possible to imitate the motion of aqueous flow around the vessel, thus simulating the conditions of moving amphibious facility. The aim of this work is to present for the first time the new device, created by us, which received a positive decision of Rospatent (Federal Service for Intellectual Property). For two months, full-scale field tests were carried out. They have showed essential qualitative and quantitative differences in the composition of fouling communities on the experimental plates, placed into the device of controlled water flow and suspended in the water column on the pier of the Zapad marine biological station of the National Scientific Center of Marine Biology, FEB RAS. Benthic diatoms predominate in the periphyton community under the conditions of the device of controlled water flow; there is practically no zoofouling. Phytocenosis of green algae, which is common for a vessel variable loadline or a hydraulic structure drainage zone, is presented on the plates from the open bay. The efficiency of using the device of controlled water flow, created by us, is shown for studying the patterns of formation of the fouling communities in different hydrodynamic flows. The main practical conclusion is that the device can be used to verify the properties of protective coatings on the substrates tested, inter alia antifouling and anticorrosive coatings.

Control of stem bending in cut gerbera flowers through application of dithiothreitol and thioglycolic acid as wound reaction inhibitors

ABSTRACT Bend neck of scape and short vase life are the most important problems of cut gerbera flowers in postharvest stage. Inhibitors of laccase enzyme influence lignin formation at cut stem end of flowers. In this study, cut gerbera (Gerbera jamesonii cv. Intense) flowers were subjected to laccase enzyme inhibitors including Dithiothreitol (DTT: 0.05, 0.1, 0.2 mM), Thioglycolic acid (TGA: 0.25, 0.5, 1 mM), or Cetyltrimethylammonium bromide (CTAB: 8, 10, 12 mM) for 20 h as pulse treatment. Results showed that 0.2 mM DTT prevented stem bending appropriately. Also, increased the vase life, maintained relative fresh weight, improved water uptake, inhibited laccase activity, and delayed the anthocyanin degradation and lignin formation. Treatment of 0.5 mM TGA had a desirable effect in extending vase life and control of stem bending. However, CTAB had negative effects on vase life of cut gerbera flowers. Thus, the presence of inhibitors in vase solution had a positive effect on control of lignin formation in end of cut stems. Our results confirmed a decrease in lignin formation at cut stem end by DTT 0.2 mM and TGA 0.5 mM. This study suggested that laccase enzyme inhibitors in vase solution are sufficient to maintain water flow process and control stem bending in cut gerbera flowers.

Studi Simulasi Pola Operasi Bukaan Pintu Bendung Gerak Mrican (Waru Turi) Kecamatan Gampangrejo Kabupaten Kediri Jawa Timur

The Mrican Weir (Waru Turi) is one of the largest motion weirs that dam the Brantas River. The weir irrigates the Waru irrigation area of 12,710 hectares and the Turi irrigation area of 16,444 hectares. The main function of the weir is to needs of irrigation water (flow control) and flood control structures. From a total of nine spillway gates, only eight gates are operating optimally. With the need for irrigation water that must be fulfilled, a new operating pattern is needed to continue to support this irrigation. The door opening operation pattern refers to the Normal Water Level at an elevation of +57.3 meters as the ideal reference. The water level receded at an elevation of +57.2 meters, and the Flood Water Level at an elevation of +58.28 meters. The simulation method for door opening (intake and spillway door) is based on irrigation requirements. With the gate opening simulation method, the maximum discharge of the spillway door (+57.3 m) is 63.67 m3/s, with an opening of 2.73 meters per door (a total of eight functioning gates). While at the Waru intake the discharge is 6.211 m3/s and Turi with a discharge of 7.936 m3/s, the maximum gate opening is 0.3 meters per door. With the new operating pattern, the discharge that flows at each intake gate still meets the needs of irrigation discharge.

Online differential pressure reset method with adaptive adjustment algorithm for variable chilled water flow control in central air-conditioning systems

Central air-conditioning systems predominantly operate under partial load conditions. The optimization of a differential pressure setpoint in the chilled water system of a central air-conditioning system leads to a more energy-efficient operation. Determining the differential pressure adjustment value based on the terminal user’s real-time demand is one of the critical issues to be addressed during the optimal control process. Furthermore, the online application of the differential pressure setpoint optimization method needs to be considered, along with the stability of the system. This paper proposes a variable differential pressure reset method with an adaptive adjustment algorithm based on the Mamdani fuzzy model. The proposed method was compared with differential pressure reset methods with reference to the chilled water differential temperature, outdoor temperature, and linear model based on the adjustment algorithm. The energy-saving potential, temperature control effect, and avoidance of the most unfavorable thermodynamic loop effects of the four methods were investigated experimentally. The results indicated that, while satisfying the terminal user’s energy supply demand and ensuring the avoidance of the most unfavorable thermodynamic loop, the proposed adaptive adjustment algorithm also decreased the differential pressure setpoint value by 25.1%–59.1% and achieved energy savings of 10.6%–45.0%. By monitoring the valve position and supply air temperature of each terminal user, the proposed method exhibited suitable online adaptability and could be flexibly applied to buildings with random load changes.

Smart system for water level and flow measurement and control in open canals

Nowadays, water and energy resources are becoming scarcer due to the inefficient use of these vital resources in agricultural irrigation worldwide. The unique solution to this problem is the application of smart technology in water distribution systems. But the most pivot weir installations in water distribution systems have not access to power and have a remote location from the power line. This problem requires developing a low-power smart system for water level and flow measurement and control in open canals. In this study, the authors attempt to detect the advantages and disadvantages of existing methods and hardware, the most important influencing factors of the system for energy efficiency, and develop a more energy-efficient and precise smart system for water flow and level measurement and controls in open canals. The question of the development of a low power smart system for water flow and level measurement and control in open canals in terms of energy efficiency is considered as well. Theoretical and experimental research results are submitted.

State primary special standard of units of mass and volume of liquid in a stream, mass and volumetric flow rates of liquid GET 63-2019

The article describes aspects of improving metrological support for measuring units of mass and volume of liquid in the flow, mass and volume flow of liquid in the Russian Federation. We consider fundamentally new design solutions for key modules of the reference unit EU-3 of the state primary special standard for units of mass and volume of liquid in the flow, mass and volume flow of liquid GET 63-2019, based on numerical and physical modeling of hydrodynamic processes under forced pressure flow of the working medium (water) in pipelines with different flow geometry. The principles of operation of water flow stabilization and control modules are substantiated. Innovative solutions are presented for the design of sensitive elements of the flow switch, the principle of constructing a time diagram, and determining the measurement time interval. Metrological characteristics of the state primary special standard of units of mass and volume of liquid in the flow, mass and volume flow of liquid GET 63-2019 are presented.

The Use of Information Systems for Regulation of Gas Engine Operating Parameters

The purpose of the work is to indicate the possibility of using selected IT systems to analyse work and regulate operating parameters of gas engines. An additional task of the work is to indicate new possibilities of using IT systems in power plants. The publication shows the development of industrial information systems in recent years. It is shown how these systems are used for direct control and adjustment of operational parameters of power equipment, ranging from water boilers to steam boilers, turbines and cogeneration aggregates. These systems implement technical safeguards and can be used to analyse work characteristics in an appropriate configuration. The more elaborate energy systems, the wider the scope of use of IT systems. Due to the full automation and control of cogeneration gas-powered power generators, an automatic heating water flow control system through heat exchangers can be used in these installations. This solution requires the expansion of the heating water pumping system with pumping sets with inverters and fittings of the pumping station with remote control.

Comparative study of thermal efficiency of flat spiral vs. conical spiral in a parabolic solar collector

Compare the thermal efficiency of two kind of heat by radiant energy concentrated by a parabolic solar collector. Methodology: became two spirals with 1.3 m length and diameter 3/8” copper pipe, which were controlled water flow from one step and recirculated making temperature measurements to water in container return and readings taken every 5 minutes. These coils were placed at the focal point of a parabolic solar collector of 77 cm in diameter and concavity of 6.6 cm. both proved to be very efficient in heat absorption and transmission to the water into itself, which showed greater heat loss but was the conical, although it wasn't exposed to air currents and that it had an aluminum housing. Meanwhile the flat spiral showed greater uniformity in the behavior of temperatures despite being exposed to air currents.The maximum temperature reached, at a flow rate of 0.15 l/min, was 97.5 ° C in 30 minutes from the initial temperature. Lower flows did not allow to make a reliable temperature reading since the water was going into its vapor phase.

On the acoustic fountain types and flow induced with focused ultrasound

Abstract

Intellectual system for water flow and water level control in water management

Currently, the shortage of water in our country is growing. This means that we must support every drop of water. At the same time, water management systems in advanced economies are used to measure and monitor water flow and water meters with different designs. Existing measurement and control systems have some drawbacks in energy saving. Therefore, the issue of improving water and energy saving water flow devices and rights management levels was considered.

Computational Fluid Dynamics Suggests Ecological Diversification among Stem-Gnathostomes

The evolutionary assembly of the vertebrate bodyplan has been characterized as a long-term ecological trend toward increasingly active and predatory lifestyles, culminating in jawed vertebrates that dominate modern vertebrate biodiversity [1-8]. This contrast is no more stark than between the earliest jawed vertebrates and their immediate relatives, the extinct jawless, dermal armor-encased osteostracans, which have conventionally been interpreted as benthic mud-grubbers with poor swimming capabilities and low maneuverability [9-12]. Using computational fluid dynamics, we show that osteostracan headshield morphology is compatible with a diversity of hydrodynamic efficiencies including passive control of water flow around the body; these could have increased versatility for adopting diverse locomotor strategies. Hydrodynamic performance varies with morphology, proximity to the substrate, and angle of attack (inclination). Morphotypes with dorsoventrally oblate headshields are hydrodynamically more efficient when swimming close to the substrate, whereas those with dorsoventrally more prolate headshields exhibit maximum hydrodynamic efficiency when swimming free from substrate effects. These results suggest different hydrofoil functions among osteostracan headshield morphologies, compatible with ecological diversification and undermining the traditional view that jawless stem-gnathostomes were ecologically constrained [9-12] with the origin of jaws as the key innovation that precipitated the ecological diversification of the group [13, 14].

Investigating alternative materials to EPDM for automatic taps in the context of Pseudomonas aeruginosa and biofilm control

Automatic taps use solenoid valves (SVs) which incorporate a rubber (typically EPDM) diaphragm to control water flow. Contaminated SVs can be reservoirs of opportunistic pathogens such as Pseudomonas aeruginosa; an important cause of healthcare-associated infection. To investigate the attachment and biofilm formation of P.aeruginosa on EPDM and relevant alternative rubbers to assess the impact on water hygiene in a laboratory model. Biofilm formation on EPDM, silicone and nitrile rubber coupons was investigated using a CDC biofilm reactor. SVs incorporating EPDM or nitrile rubber diaphragms were installed on to an experimental water distribution system (EWDS) and inoculated with P.aeruginosa. P.aeruginosa water levels were monitored for 12-weeks. SVs incorporating diaphragms (EPDM, silicone or silver ion-impregnated silicone rubber), pre-colonized with P.aeruginosa, were installed and the effect of flushing as a control measure was investigated. The concentration of P.aeruginosa in the water was assessed by culture and biofilm assessed by culture and microscopy. Bacterial attachment was significantly higher on nitrile (6.2×105 cfu/coupon) and silicone (5.4×105 cfu/coupon) rubber than on EPDM (2.9×105 cfu/coupon) (P<0.05, N=17). Results obtained invitro did not translate to the EWDS where, after 12-weeks in situ, there was no significant difference in P.aeruginosa water levels or biofilm levels. Flushing caused a superficial reduction in bacterial counts after <5min of stagnation. This study did not provide evidence to support replacement of EPDM with (currently available) alternative rubbers and indicated the first sample of water dispensed from a tap should be avoided for use in healthcare settings.

A successful process to prevent corrosion of rich Gd-based room temperature magnetocaloric material during ageing

When the heat transport processes occur in a magnetic refrigeration device, there is possibility of corrosion thereforth, insight on the magnetocaloric regenerator corrosion could be shed in light. Our work mimicks this phenomenon by subjecting the magnetocaloric material Gd6Co1.67Si3 to controlled water flow. The corrosion is first explained based on the elemental electrochemical oxidation thereby allowing a new test by the exposing material in passive fluid (KOH) up to 1 year. The neglected degradation of the material was justified by X-Ray photoelectron spectroscopy (XPS) and depth profile Auger spectroscopy, and thus the control of its corrosion is reported. The effective control of the corrosion when material is exposed to KOH could be a universal procedure in magnetic refrigeration prototype.

Numerical investigation of the large over-reading of Venturi flow rate in ARE of nuclear power plant

Venturi meter is frequently used in feed water flow control system in a nuclear power plant. Its accurate measurement plays a vital role in the safe operation of the plant. This paper firstly investigates the influence of the length of each section of pipeline, the throat inner diameter of Venturi and the flow characteristics in a single-phase flow on the accuracy of Venturi measurement by numerical calculation. Then the flow and the accuracy are discussed in a multi-phase flow. Numerical results show that the geometrical parameters and the characteristics of complex turbulent flow in the single-phase flow have little impact on the accuracy of Venturi flow rate measurement. In the multi-phase flow, the calculated flow rate of Venturi deviated from the actual flow rate and this deviation value is closely related to the amount of steam in the pipeline and increases sharply with the increase of the amount of steam. The over-reading of Venturi flow rate is present.

Influence of auxiliary cylinders on the dynamics of overland flow upstream of the main cylinder based on particle image velocimetry

The position of auxiliary cylinders in flow experiments noticeably affects soil erosion and pollutant transportation processes by altering the dynamic flow field in front of the main cylinder. However, few studies have been conducted for overland flow due to the shallow flow depth and limited observation technology. In this study, we conducted fixed-bed flume experiments and developed a high-resolution and high-frequency particle image velocimetry system to investigate the two-dimensional dynamic field of overflow using a symmetrical surface (i.e., the vertical plane passing through the axis of the main cylinder in the flow direction) upstream of the main cylinder as the observation area. Two auxiliary cylinders in each position were placed upstream, parallel, and downstream (i.e., pre-column condition, parallel condition, and post-column condition, respectively). Results showed that: For a given flow discharge, the ranking of the cylinder configurations in terms of the stability of the hydrodynamic conditions (velocity, turbulent energy, shear force, and Reynolds stress) was pre-column condition < parallel condition < post-column condition. The number of horseshoe vortices and the rotation intensity of the main horseshoe vortex were similar for the three configurations. The position of the main horseshoe vortex was closest to the main cylinder in the pre-column condition, causing substantial soil erosion around the main cylinder. For different flow rates, the water depth and turbulent intensity showed monotonic increasing trends as the flow discharge increased, whereas the shear force and Reynolds stress exhibited a single peak. As the Reynolds number of the cylinder increased, the flow separation point moved upstream, and the rotation intensity of the main horseshoe vortex was negatively correlated with the water depth. Therefore, a shallower water depth corresponded to significantly greater erosion damage by the horseshoe vortex. Overall, the configuration of the auxiliary cylinders downstream of the main cylinder resulted in the optimum water flow control. The findings of this study provide theoretical support for designing vegetation management strategies that minimize soil erosion and protect water resources.

Field observations of soil hydrological flow path evolution over 10 millennia

Abstract. Preferential flow strongly controls water flow and transport in soils. It is ubiquitous but difficult to characterize and predict. This study addresses the occurrence and the evolution of preferential flow during the evolution of landscapes and here specifically during the evolution of hillslopes. We targeted a chronosequence of glacial moraines in the Swiss Alps to investigate how water flow paths evolve along with the soil-forming processes. Dye tracer irrigation experiments with a Brilliant Blue FCF solution (4 g L−1) were conducted on four moraines of different ages (30, 160, 3000, and 10 000 years). At each moraine, three dye tracer experiments were conducted on plots of 1.5 m ×1.0 m. The three plots at each moraine were characterized by different vegetation complexities (low, medium, and high). Each plot was further divided into three equal subplots for the application of three different irrigation amounts (20, 40, and 60 mm) with an average irrigation intensity of 20 mm h−1. The day after the experiment five vertical soil sections were excavated, and the stained flow paths were photographed. Digital image analysis was used to derive average infiltration depths and flow path characteristics such as the volume and surface density of the dye patterns. Based on the volume density, the observed dye patterns were assigned to specific flow type categories. The results show a significant change in the type of preferential flow paths along the chronosequence. The flow types change from a rather homogeneous matrix flow in coarse material with high conductivities and a sparse vegetation cover at the youngest moraine to a heterogeneous infiltration pattern at the medium-age moraines. Heterogeneous matrix and finger flow are dominant at these intermediate age classes. At the oldest moraine only macropore flow via root channels was observed in deeper parts of the soil, in combination with a very high water storage capacity of the organic top layer and low hydraulic conductivity of the deeper soil. In general, we found an increase in water storage with increasing age of the moraines, based on our observations of the reduction in infiltration depth as well as laboratory measurements of porosity. Preferential flow is, however, not only caused by macropores, but especially for the medium-age moraine, it seems to be mainly initiated by soil surface characteristics (vegetation patches and microtopography).

Numerical simulation of temperature field and pressure field of the fracture system at Zhangzhou geothermal field

Zhangzhou geothermal field is one of the highest temperature in southeastern coastal areas in China. Zhangzhou geothermal field is an uplift-fracture type geothermal resource, and there are several deep fractures in the geothermal field, controlling water flow and heat transfer. Presently there is no systematic study of the characteristics of the temperature field, pressure field and water density distribution in the geothermal field, and there is no systematic analysis of the main factors affecting the temperature field. In this work, geological features of the fracture system are considered, and a conceptual model of the fracture system is established. Based on these, the distribution of the temperature field, pressure field and water density field at Zhangzhou geothermal field are numerically studied, the controlling effect of the fracture system on the temperature field is analyzed, and the main factors affecting the temperature field, pressure field and water density field are discussed. The results indicate that the temperature field and water density field at Zhangzhou geothermal field are strongly controlled by the fracture system, and the zone of high-temperature and low-density is confined within the fracture system. Main factors affecting the temperature field and water density field include the permeability of the fracture zone, the thermal conductivity of rocks and the water recharge rate. Higher fracture zone permeability will reduce the temperature and increase the water density in the center of the fracture system. Higher water recharge rate will increase the temperature and reduce the water density in the center of the fracture system.

Laboratory bench to analyze of automatic control system with a fuzzy controller

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