Mounting Height Research Articles

Evaluating the effect of operating pressure, nozzle size and mounting height on droplet characteristics of rotating spray plate sprinkler

Evaluating the effect of operating pressure, nozzle size and mounting height on droplet characteristics of rotating spray plate sprinkler

Study on the influence of baffle height and angle on the performance of coarse powder separator in power plant based on CFD-DPM method

In this study, the two-phase motion characteristics in a coarse powder separator were investigated using computational fluid dynamics (CFD) method, discrete particle model (DPM) and isokinetic sampling experimental method, and the structure of the coarse powder separator was optimized to improve the efficiency of the separator. The results showed that the particle separation in different separation zones was also dominated by gravity separation and centrifugal separation, respectively. When the baffle angle was increased from 20° to 60° at a low mounting height, the tangential velocity in the separation zone was reduced by 67 % and the axial velocity was increased by 33 %. The effects of the baffle angle on the tangential and axial velocities were weakened with the rise of the baffles mounting height. The optimum operating condition of the chosen powder separator involved a baffle angle α 30°, a baffle height H = 6.27 m, and a inlet velocity v = 19.3 m/s. The fineness of coal powder at the fine powder outlet was reduced by 60 % and the fineness of coal powder at the coarse powder return port was improved by 43 % for the optimized model compared with the original coarse powder separator.

An asymmetric road lighting concept: Probeam

An asymmetric road lighting concept known as Probeam is investigated in this study for energy efficiency, contrast and visibility of vertical objects and road markings in highway lighting. Calculations based on road lighting standards, road surface and markings reflection characteristics and typical Dutch highway geometry, reveal that Probeam lighting improves the average visibility of objects and road markings over symmetrical lighting, however, with a 14% increase in luminous flux as per current road lighting standards. This increase in luminous flux is attributed to the symmetrical lighting’s advantage in specular road surface reflection, leading to a reduction in the Counterbeam lobe size in the light intensity distribution when designed to meet the current road luminance requirement. Notably, by designing the Probeam luminaire to match symmetrical lighting’s average visibility of vertical objects, for removing the road luminance requirement and dimming the luminaire, energy consumption is reduced by 52%. Halving the Probeam luminaire’s mounting height leads to an impressive 82% energy savings. The study highlights the possibility of a balance in energy use and road safety using the Probeam concept, considering advancements in road luminaires and retroreflective materials. Due to glare, the relevance of the proposed Probeam concept is restricted to one-directional traffic on highways.

Enhancing Heliostat Field Performance: A Comprehensive Study on Optical Efficiency and Annual Thermal Power

The many advantages of solar photovoltaic technology make it bound to be commercially competitive in the coming years, and its development is strategically important. The parameters of the heliostat field, including the positional coordinates of the absorber tower, the size and mounting height of the heliostat mirrors, as well as the number and position of the heliostat mirrors, are designed according to the requirement of the rated annual average thermal power output of 60 MW so that the heliostat field will have the largest possible annual average thermal power output per unit of mirror area under the condition of reaching the rated power. Larger sizes and higher mounting heights of heliostats help to capture more solar energy and thus increase the annual average output thermal power per mirror area. The efficiency and output thermal power of heliostats of different sizes and mounting heights are evaluated by simulating the numerical calculation method and the best combination is found.

Subgrade Reaction Characteristics to the Anchor Pile of a Sheet Pile Quay Wall

The Conventional Design Method (CDM) for anchored sheet pile quay walls cannot accurately calculate the anchor pile deformation, partly because it does not properly consider the subgrade reaction. This study aims to clarify the subgrade reaction characteristics of the anchor pile using finite element analysis. The CDM assumes that passive failure occurs at the front of the anchor pile. On the contrary, this study shows that the active failure region generated from the back of the sheet pile wall expands to the periphery of the anchor pile and the passive failure region is not generated at its front. Thus, the subgrade reaction to the anchor pile is found to be smaller than the CDM assumption. The CDM also neglects the subgrade reaction in parts shallower than the tie-rod mounting height in the pile front. This study clarifies that the subgrade reaction in this part greatly contributes to the deformation resistance of the pile. Consequently, the subgrade reaction in the shallower range than the tie-rod mounting height is greater than or equal to that in the deeper range. Furthermore, the subgrade reaction has a lower upper limit when acting on the anchor pile than when acting on a horizontally stratified ground, and the difference between these limits widens as the reference earthquake strengthens.

Optimal arrangement of heliostat field based on simulated annealing algorithm

In this study, a simulated annealing algorithm is proposed as an optimisation method for the mirror arrangement of heliostat mirrors in a tower solar thermal power plant. Firstly, the optimal number and position of heliostats in the whole mirror field in radial staggered layout (EB unobstructed layout) were solved using simulated annealing method. Then further optimisation, i.e. changing the mirror width, mirror height and mounting height of the heliostats and solving for the optimal number and position of heliostats using simulated annealing again, resulted in an increase in the number of heliostats in the optimised mirror field by 77.92% but a decrease in the total area by 18.77%, and an increase in the average annual thermal power output per unit area of the mirrors by 4.76%. Therefore, this result shows that the heliostat field optimised using the simulated annealing algorithm has a higher efficiency and a smaller footprint.

Evaluation of in situ observations on Marine Weather Observer during Typhoon Sinlaku

Abstract. The mobile ocean weather observation system, named Marine Weather Observer (MWO), developed by the Institute of Atmospheric Physics (IAP), consists of a fully solar-powered, unoccupied vehicle and meteorological and hydrological instruments. One of the MWOs completed a long-term continuous observation, actively approaching the center of Typhoon Sinlaku from 24 July to 2 August 2020, over the South China Sea. The in situ and high-temporal-resolution (1 min) observations obtained from MWO were analyzed and evaluated through comparison with the observations made by two types of buoys during the evolution of Typhoon Sinlaku. First, the air pressure and wind speed measured by MWO are in good agreement with those measured by the buoys before the typhoon, reflecting the equivalent measurement capabilities of the two methods under normal sea conditions. The sea surface temperature (SST) between MWO and the mooring buoys is highly consistent throughout the observation period, indicating the high stability and accuracy of SST measurements from MWO during the typhoon evolution. The air temperature and relative humidity measured by MWO have significant diurnal variations, generally lower than those measured by the buoys, which may be related to the mounting height and sensitivity of sensors. When actively approaching the typhoon center, the air pressure from MWO can reflect some drastic and subtle changes, such as a sudden drop to 980 hPa, which is difficult to obtain by other observation methods. As a mobile meteorological and oceanographic observation station, MWO has shown its unique advantages over traditional observation methods, and the results preliminarily demonstrate the reliable observation capability of MWO in this paper.

Assessment of energy gain in SPV Tree structure with bifacial PV modules in Rajasthan

With the rising use of renewable energy generation sources, there is a need for dependable and sustainable measuring techniques to monitor and measure the performance of the energy sources. Existing guidelines and standards for measurement of performance of PV modules are specified only for monofacial PV modules, in which the measurement of irradiance falling on the PV module is irrespective of the ground-clearance or mounting height up to a certain extent. With reference to techno-commercial aspects, the pitch in a ground-mounted power plant is set based on how optimum energy generation can be obtained with minimum land utilization. In case of bifacial PV modules, generation gain can be achieved by varying the ground-clearance/mounting height of the modules as the energy generation depends on the irradiance on both front as well as back side of the module. In this research study, the authors have compared field measurements of energy gained by varying the ground-clearance of bifacial PV modules by using bifacial PV modules in a novel structure of SPV Tree. The simulation and practical results show that the energy gain increases up to 3.5% in Marigold SPV Tree structure as the mounting height is 4 m, contrary to a conventional ground-mounted structure with mounting height 0.5 m from the ground.

混秸带翼凿式犁关键部件扰动规律的研究

Understanding the soil-straw disturbance pattern of the key component parameters of the straw mixing winged chisel plow is the key to designing and optimizing the straw mixing winged chisel plow (a chisel plow for mixing and mulching straw). In this study, a straw-soil-winged chisel plow interaction model was established, and the working principle, key components of the winged chisel plow were determined based on soil bin experiment and theoretical analysis. Discrete element method (DEM) was used to study the influence of disturbance pattern of key components of the winged chisel plow on soil-straw displacement, straw mixing rate and draught force. The results show that the main components of the winged chisel plow that affect the operating efficiency of the implement are the soil lifting plate height, the wing mounting height and the wing width. The height of the soil lifting plate affects the efficiency of the winged chisel plow in secondary disturbance of soil-straw and its own performance in turning over soil, with an optimal range of 110 mm-170 mm. The installation height of the wing mounting mainly affects the position of the soil lifting plate in the soil layer. In order to achieve the best operating effect, the position of the soil lifting plate needs to meet the "lower lifting and upper turning" requirement. The optimal installation height of the wing mounting is 95 mm-145 mm. The width of the wing mainly affects the working width of the implement, and its optimal value is 180 mm-220 mm. The width of the wing mainly affects the working width of the implement, and its optimal value is 180 mm-220 mm. The established simulation relative error is within 12.60%, which can better study the disturbance pattern of soil-straw. This study may provide a reference for optimizing and designing wing-type chisel plows and subsoil shovels.

Tri-axial shaking table testing of lighting support systems with pulley friction dampers and integrated dummy masses

Investigating pulley wireway systems equipped with friction dampers as alternatives to traditional exposed raceway light fixtures, this study adheres to the ICC-ES AC156 standard and evaluates the impact of system mass and connector types on seismic behavior using shaking table tests. The key findings indicate that an increased system mass variably affects the fundamental frequency of the system, depending on the type of connectors. In terms of earthquake performance, direct connectors outperformed pole connectors in the original system configuration, and the addition of dummy masses significantly reduced seismic energy while stabilizing acceleration responses in pole connector systems. Moreover, the study underscores the critical importance of minimizing pole length in systems using pole connectors and adopting a lower mounting height in systems with direct connectors to improve seismic performance.

A horizontal single-axis tracking bracket with an adjustable tilt angle and its adaptive real-time tracking system for bifacial PV modules

An efficient photovoltaic (PV) tracking system enables solar cells to produce more energy. However, commonly-used PV tracking systems experience the following limitations: (ⅰ) they are mainly applied to single-sided PV panels; (ⅱ) they employ conventional astronomical algorithms that cannot adjust the tracking path in real time according to variable weather. In this study, a model of horizontal single-axis tracking bracket with an adjustable tilt angle (HSATBATA) is developed, and the irradiance model of moving bifacial PV modules is designed, which considers the mounting height, spacing and ground shading of PV panels. Furthermore, an adaptive real-time tracking (ARTT) algorithm is put forward to obtain the optimal tracking path for PV cells, which considers the energy consumption of tracking motors, the front and back irradiance of solar cells, cell temperature and ambient wind speed. The test results indicate that the presented ARTT algorithm enhances the energy of PV modules by 32.7 % and 7.5 %, respectively, compared to the fixed bracket and the conventional tracking algorithm. Additionally, the number of motor starts of the PV tracking system is reduced by 71.7 % compared with that of the conventional algorithm, which greatly contributes to extending the service life of PV tracking brackets and lowering the cost of electricity. Present study will help to improve the theoretical research system of PV tracking bracket construction, irradiance modeling of moving bifacial modules, and intelligent tracking algorithms.

Effects of Subsoiling with Different Wing Mounting Heights on Soil Water Infiltration Using HYDRUS-2D Simulations

Subsoiling is an essential practice in conservation tillage technology. The amount of disturbed soil at various depths resulting from subsoilers with different parameters has an important effect on soil properties (e.g., bulk density and water infiltration). The information regarding the effects of subsoiling on the characteristics of soil water infiltration is essential for the design of subsoiling tools. In this study, the effects of the wing mounting height (h) (75–155 mm) of the subsoiler on soil disturbance and soil water infiltration were modelled using HYDRUS-2D and validated using field experiments. Results showed that reducing h values resulted in larger soil disturbance area ratios, soil water infiltration rates (f(t)), distances of vertical wetting front movement (DVWs), accumulative infiltrations (AINs), and soil moisture contents at depths of 10–30 cm. The relationships among characteristics of soil water infiltration, h and time (t), were developed. The stable infiltration rates (fs) varied quadratically with h and the corresponding coefficient of determination (R2) was 0.9869. The Horton model is more suitable for describing the relationship between f(t) and t under the tested soil conditions, as compared with the Kostiakov and Philip models. According to the results of soil water content at different depths from the HYDRUS simulations and field experiments, the developed soil water infiltration model had a good accuracy, as indicated by RMSEs of <0.05, R2 values of >0.95, and mean relative errors of <12%. The Above results indicated that increasing the hardpan disturbance by optimizing wing parameters of the subsoiler could improve soil water infiltration characteristics.

Development and Evaluation of a MASH TL-3 Modified Single Wood-Post Skid-Mounted Sign Support System

Previous crash testing determined that the conventional Texas Department of Transportation, U.S., single wood-post, skid-mounted temporary sign support system did not satisfy guidelines included in the American Association of State Highway and Transportation Officials Manual for Assessing Safety Hardware (MASH). Modifications were made to the system to improve impact performance and meet MASH requirements. The modifications included increasing the mounting height of the sign, installing weakening holes in the wood support post at a prescribed height, and adding a wire rope loop around the weakening holes to act as a hinge mechanism when sections of the wood sign support fracture during vehicle impact. Crash tests were performed on the modified system in accordance with the MASH Test Level 3 (TL-3) matrix for work-zone traffic control devices. The modified single wood-post, skid-mounted temporary sign support system with a 90 in. sign mounting height, weakening holes, and tether cable met the performance criteria for MASH TL-3 work-zone traffic control devices.

Agrivoltaic, a Synergistic Co-Location of Agricultural and Energy Production in Perpetual Mutation: A Comprehensive Review

Agrivoltaic systems, which consist of the combination of energy production by means of photovoltaic systems and agricultural production in the same area, have emerged as a promising solution to the constraints related to the reduction in cultivated areas due to solar panels used in agricultural production systems. They also enable optimization of land use and reduction in conflicts over land access, in order to meet the increasing demand for agricultural products and energy resulting from rapid population growth. However, the selected installation configurations, such as elevation, spacing, tilt, and choice of panel technology used, can have a negative impact on agricultural and/or energy production. Thus, this paper addresses the need for a review that provides a clear explanation of agrivoltaics, including the factors that impact agricultural and energy production in agrivoltaic systems, types of panel configurations and technologies to optimize these systems, and a synthesis of modelling studies which have already been conducted in this area. Several studies have been carried out in this field to find the appropriate mounting height and spacing of the solar panels that optimize crop yields, as this later can be reduced by the shade created with the solar panels on the plants. It was reported that yields have been reduced by 62% to 3% for more than 80% of the tested crops. To this end, an optimization model can be developed to determine the optimal elevation, spacing, and tilt angle of the solar panels. This model would take into account factors that influence crop growth and yield, as well as factors that affect the performance of the photovoltaic system, with the goal of maximizing both crop yield and energy production.

Sharing 5G Antenna with Transmission Tower: Mounting Height, Arrangement, Electromagnetic Interference and Overall Safety

The demand for communication base stations in the 5G era has increased dramatically, the current large-scale transmission towers are important carrier for 5G equipment sharing construction. For the transmission system, the current and previous load code for the design of overhead transmission line in China are investigated. Different wind load specification on the conductors, ground wires and 5G equipment on the transmission towers are studied in finite element coupling model. In addition, the influence of soil and electromagnetic is also considering in calculation model. According to mechanical and simulation model, the structural response of the transmission tower with sharing 5G antenna including different mounting height and arrangement is discussed. Finally, comparison on maximum stress ratio of different horizontal span and overall safety of shared tower is evaluated.

Modelling the spray range of rotating nozzles based on modified ballistic trajectory equation parameters

AbstractThe nozzle spray range is an important parameter in the design of sprinkler systems because it affects the wetted area and water application rate. In this study, the jet deformation parameter kjet, which can measure the mass and shape of the jet microelement, was investigated, and a spray range prediction model for a rotating nozzle was established based on the modified ballistic trajectory equation. A comparison verified the accuracy of the model, and the degree of influence of different factors on the spray range was analysed. The results showed the following: (1) The dimension of the jet deformation parameter kjet is the length L, which is a function of the nozzle diameter, working pressure and nozzle elevation angle. (2) The maximum mean absolute error and root mean square error of the current model at a nozzle elevation angle of 24° were 2.038 and 1.603, respectively, representing a maximum increase in prediction accuracy of 87% and 86.7%, respectively, over other models at the same angle. (3) A sensitivity analysis revealed that the factor with the greatest impact on the nozzle spray range was the nozzle diameter, and the smallest was the nozzle mounting height. (4) The maximum nozzle spray range was positively related to the nozzle diameter and working pressure, and the nozzle elevation angle varied at approximately 30° when the maximum range was reached. This study provides a reference for the design of sprinkler systems and the development of rotating nozzles.

Обоснование параметров системы искусственного светодиодного освещения животноводческих помещений

Lighting of livestock buildings affects the productivity of animals. The system of artificial LED lighting provides the reduction of energy costs in the livestock production at agro-industrial enterprises. A mathematical model is presented to substantiate the parameters of the system of artificial LED lighting of livestock premises. The system of artificial LED lighting should provide regulation of illumination depending on breed and light perception channels of an animal, use control programs of radiation spectrum and illumination duration. The results of mathematical analysis determined that illuminance, uniformity of illumination in livestock premises and power consumption of the LED system depends on the mounting height of lighting devices, as well as the type of light intensity curve, which are determined by the geometric features of LED lighting devices. The emission spectrum is determined by the type of LED light sources, while the duration and periodicity of the daylight hours is provided by the LED software devices. The development of new design solutions of lighting devices will increase the livestock productivity and reduce energy costs.

Optimal tunnel lighting design in aspect of lighting quality and energy performance

The lighting quality and energy performance of tunnel lighting systems based on different tunnel lighting designs are investigated to identify the optimal tunnel lighting design. Furthermore, the lighting qualities of various mounting heights and luminaire spacing are discussed based on different tunnel lighting parameters. Thereafter, the luminaire spacing is optimized for various road widths and luminaire power. Finally, the effects of the surface reflectance of the wall, ceiling, and road are compared in terms of the lighting quality and energy performance. The results indicate that the mounting patterns have a significant effect on the average luminance in the single-row arrangement. A symmetrical system with ceiling mounting can provide remarkable overall and longitudinal uniformities. Reducing the mounting height from 7 m to 5.5 m results in greater average luminance and better TI of about 11 % and 45 % respectively, but the overall and longitudinal uniformities are degraded by 20 % − 30 % and 30 % − 45 % respectively. In addition, reducing the distance between the luminaires from 30 m to 10 m improves the total tunnel lighting quality, i.e., 67 % of average luminance, 55 % of overall uniformity, 75 % of longitudinal uniformity, and 60 % of TI. In addition, the road, wall, and ceiling surface reflectance have a dominant effect on the lighting quality. A tunnel surface with low reflectance degrades the lighting quality, resulting in minimum luminaire spacing and poor energy efficiency.

Influence of nozzle structure on the combustion performance of a graphitic hydrogen-chlorine synthesis combustor

The growing semiconductor sector is driving up demand for high-purity gas-phase HCl. Large combustion zones and low HCl concentrations are problems for HCl manufacturing systems. Based on the realizable k-ε model, the eddy breakup combustion model, and the participating media radiation model, the computational fluid dynamics simulation was used as the primary means in this study. The influence of four structural factors, nozzle jet hole diameter, jet angle, and opening angle—another is nozzle mounting height, on the combustion effect of the synthesis combustor was investigated. The extent of the high-temperature zone in the synthesis combustor and the purity of the hydrogen chlorine at the outlet were used as the main evaluation criteria. The results of numerical simulations demonstrate that the better the gas mixing and combustion in the combustor, the lower the nozzle mounting height should be. Small nozzle diameters and large nozzle jet angle increase gas flow velocity in the recirculation zone close to the inner wall of the combustor. Additionally, the recirculation zone will appear in the combustor as a result of the nozzle's presence. The area of the high-temperature zone within the combustor decreases as internal gas velocity increases. On the other hand, the recirculation gas flow is not significantly impacted by the angle at the condition that the jet holes open. The results of the investigation provide a reference for the design of the miniaturization of the combustor in the non-premixed combustion synthesis of gases process.

Variation of Subsoiling Effect at Wing Mounting Heights on Soil Properties and Crop Growth in Wheat–Maize Cropping System

Subsoiling is an effective practice to promote better soil water infiltration and crop growth. The information regarding the variation and persistence of subsoiling effects with different soil disturbance on soil properties and crop growth was absent in previous research. In this study, the effects of wing mounting height (h) (75–155 mm) during subsoiling on soil disturbance at various layers, soil properties and crop performance were investigated using in situ field experiments from 2019 to 2021 in winter wheat–summer maize rotations. The experimental field soil was covered with crop stubble and crop straw was removed before subsoiling or sowing the next crop. The analysis of variance (ANOVA) was used to assess different subsoiling treatment effects on tested variables, including soil moisture content, bulk density, plant diameter, plant height, dry root weight, root number, yield, and yield components of crops. Means between subsoiling treatments were compared using Duncan’s multiple range tests. Based on ANOVA outputs, the h significantly (p < 0.05) affected soil moisture content in the first growing season of winter wheat (WW1), soil bulk density, number of roots and panicle number and grain yield of WW1, and thousand kernel weight (TKW) of both WW1 and summer maize (SM). Decreasing h overall gave better soil properties and crop performance. Decreased subsoiling effects were found on aspects of insignificant difference in subsequent grain yield of SM and winter wheat in the second growing season (WW2). These findings had implications for designing higher-performance winged subsoilers, as well as selection of subsoiling frequency.