Horizontal Installation Research Articles

Development of a finite element groundwater flow model to test drainage management strategies for the expansion of the Dareh-Zar open pit mine, Iran

A finite-element groundwater flow model was developed for the expanding Dareh-Zar open pit mine in southern Iran, to simulate groundwater inflow into the excavation and mine wall pore pressure dynamics. The model was used to test the effectiveness of implementing different drainage management strategies to reduce groundwater inflow rates and mine wall pore pressures, including abstraction wells and horizontal drains. Model predictions suggest the implementation of abstraction wells will reduce groundwater inflow rates by 75% during the first 12 years of mining and 50% during the subsequent 5 years relative to a ‘no drainage’ management scenario, with further reductions in groundwater inflow achieved through horizontal drain installation. Furthermore, the installation of horizontal drains was found to be necessary to reduce mine-wall pore pressures from destabilizing the mine walls. Groundwater management of the decommissioned pit mine was also evaluated, with simulation results suggesting that backfilling the excavation would restore the groundwater level within the open pit mine region to ~2,442 m above sea level, representing a net restoration of ~204 m relative to the water table prior to mine closure.

Synergistic impact of horizontal fin installation height and nanoparticle volume fraction to enhance charging performance of phase change materials (PCMs)

This study numerically analyses the synergistic influence of nanoparticle and orthogonal fin on heat transfer performance of phase change materials using enthalpy-porosity method. The natural convection heat transfer and heat conduction during the melting process are coordinated by varying nanoparticle volume fraction and installation height of fin. Results illustrate that the optimal installation height of horizontal fin and nanoparticle volume fraction is 8.9 mm and 1.0 vol%, respectively. The corresponding total melting time is 1024 s and average energy charging rate is 484.5 W. Compared with the optimum conditions without nanoparticle (φ = 0.0 vol% and d = 7.0 mm), total charging time is reduced by 29.8% and average charging rate is increased by 51.1%. The equivalent Nusselt number demonstrates that the addition of high volume fraction nanoparticle decreases the convective heat transfer intensity. The low volume fraction nanoparticle enhances PCM thermal conductivity and has an insignificant effect on natural convective heat transfer. The Prandtl number demonstrates that when the volume fraction is 1.0 vol%, the effect of increasing thermal conductivity on strengthening heat conduction is greater than the negative effect of decreasing natural convection heat transfer caused by viscosity. Effective design guidelines to improve thermal charging performance of PCM-based LHTES devices are finally provided.

Anti-galloping analysis of iced quad bundle conductor based on compound damping cables

Based on the strain displacement relationship of spatial curved beam theory, a nonlinear dynamic equation for a hybrid model of iced bundle conductor galloping analysis with three translational degrees of freedom and one rotational degree of freedom was established. The element independence is numerically studied, and the impact of modal truncation on the galloping response is analyzed to verify the accuracy of the model. In addition, the compound damping cable is applied to transmission lines for the first time to prevent galloping, and a corresponding nonlinear vibration control finite element equation for the iced quad bundle conductor with a compound damping cable structure under wind load is developed. The study also examines the influence of various parameters on galloping amplitude. The results show that the hybrid model accurately predicts the galloping response of transmission lines. The compound damping cable can effectively suppress the galloping of the quad bundle conductor, and the vibration reduction effect reaches more than 85%. Increasing the installation height of the compound damping cable improves its damping effect. At the same installation height, when the horizontal installation position is close to the mid-span of the conductor, the damping effect first increases and then decreases, suggesting an optimal installation position exists. Moreover, properly increasing the stiffness of the primary cable and reducing the stiffness of the return spring can improve the vibration reduction effect of the compound damping cable. Additionally, if the damping coefficient and the mass of the primary cable are properly increased, the vibration reduction effect of the compound damping cable will be better.

Structural Performance Evaluation of Cross Dapped Connection for Vertical Wall to Wall Connection of Precast Wall Panel

In the context of Industrialised Building Systems (IBS), precast concrete buildings are composed of multiple structural members that are interconnected through different techniques. The adoption of precast concrete wall panels has gained significant traction in contemporary construction methodologies. Nevertheless, the utilization of dapped connections specifically designed for non-load bearing applications in precast walls incorporating recycled concrete aggregate (RCA) remains largely unexplored and limited in practice. This research proposes a new wall-to-wall connection for precast wall panels to enhance the constructability of IBS for non-load bearing walls. The novel Cross Dapped (CD) design enables horizontal panel installation in confined areas with existing structural frames, while ensuring the connection’s strength as a non-load bearing wall to prevent failure. Uniformly distributed loads are applied until sample failure, recording compressive load patterns, deflection, stress-strain patterns, and crack patterns on the wall surface. The CD connection demonstrates applicability for precast wall-towall connections, improving IBS constructability with its innovative design and locking system. Overall, this research explores and proposes an efficient and structurally sound wall-to-wall connection design for precast wall panels of non-load bearing system, facilitating the adoption of IBS methods, and improving the overall quality and constructability of building systems.

Test and analysis of friction torque of double-row angular contact ball bearing under vacuum environment

PurposeThe purpose of this paper is to test and analyze the friction torque of double-row angular contact ball bearings under vacuum or ordinary pressure environment, horizontal or upright installation mode, and different rotational speeds, and to provide theoretical bases for the development of aerospace equipment.Design/methodology/approachThe experiments were carried out to investigate the effects of vacuum or ordinary pressure environment, horizontal or upright installation mode and different rotational speeds on bearing friction torque. To explore the relationship between working conditions and bearing friction torque, firstly, based on the generation source of friction torque, the test principle was determined, a test system was developed and the reliability of data was verified. Secondly, the friction torque of bearing was tested, and the values under various working conditions were obtained. Finally, this paper compared and discussed the test results.FindingsThe test results show that the friction torque value of vacuum environment horizontal installation condition is the largest at different rotational speeds, and the rotational speed has the most significant influence on the friction torque.Originality/valueThe friction torque test system of double-row angular contact ball bearing under vacuum environment was designed and built. The influence rules of vacuum or ordinary pressure environment, horizontal or upright installation mode and different rotational speeds on bearing friction torque were obtained.Peer reviewThe peer review history for this article is available at: http://dx.doi.org/10.1108/ILT-08-2023-0259

Evaluating Transient Drawdown and Slope Stabilization from Horizontal Drain Installation

Elevated groundwater levels drive slope instability through decreased effective stresses and frictional strength. Consequently, landslide mitigation often relies on a variety of stabilizing techniques, often including dewatering and drainage as a primary control on stability. One of the most effective dewatering techniques for landslides are horizontal drain systems, which consist of arrays of perforated pipes drilled into hillslopes for gravity-driven removal of groundwater. One of the few economical solutions for large-magnitude, groundwater-driven landslides, horizontal drain arrays facilitate groundwater drawdown through gravity-driven flow, consequently increasing effective stress and slope stability within its domain of influence. However, design of horizontal drain systems remain largely observational and there is limited insight towards the transient performance of these drainage systems. This study aims to explore relevant theoretical design criteria for horizontal drain systems and their relative importance as related to drawdown mechanism and magnitude, as well as slope stability.

Numerical modeling and cooling performance evaluation of a pressure-driven two-phase closed thermosyphon with a long horizontal evaporator

In the quest to improve thermal regulation within permafrost embankments, the permafrost thermosyphons equipped with horizontal evaporators remains underexplored in scholarly discourse in open. This study delineates the design and numerical evaluation of a pressure-driven two-phase closed thermosyphon (PD-TPCT), featuring a horizontal evaporator exceeding 100 m. A half-theory heat transfer model, borne from a synergy of monitoring data and the thermal resistance method, was derived from an outdoor experimentation. Considering the growing global focus on the sustainable development of the Arctic and the Third Pole, we employ this heat transfer model to analyze the long-term thermal stabilities of a PD-TPCT embankment, a PD-TPCT embankment with insulated boards, and an unprotected embankment (as a control) in the Siberian Arctic (SA) and Qinghai-Tibet Plateau (QTP). This study reveals that the horizontal installation of the evaporator can mitigate the shady-sunny slope effect and improve the thermal stability of the underlying permafrost. The SA's climate allows the PD-TPCT embankment to protect permafrost for 50 years, while in the QTP, the PD-TPCT embankment with insulated boards is needed for the same protection. The insights garnered herein offer references to both the theoretical exploration and pragmatic implementation of advanced thermosyphon with ultra-long horizontal evaporators.

Model development of deep space-source heat pump system and its feasibility analysis

This study proposes a novel deep space-source heat pump (DSSHP) system for efficient heat rejection, considering the spectral selectivity of cooling coatings and atmospheric windows, the influence of tilt angles and cloud cover fractions. Then, the long-term operation performances of the DSSHP are investigated under various working conditions. The results indicate that the optimal DSSHP operation conditions include a lower flow rate, horizontal installation of environment-side water-to-air radiators, and clear sky. The proposed system shows better economic and cooling-efficiency advantages. Compared with air-source heat pump (HP) and ground-source HP, the DSSHP payback period is only 5.1 years, and its cooling season average COP is comparable to ground-source HP (at 5.3). Moreover, this cooling system also shows high geographical adaptability for actual applications. The COP of the system in the highland city (Lhasa) can reach 6.7 on the cooling season average. Even in a tropical city (Hong Kong), the COP can still reach 5.3. Besides, this cooling system exhibits high spectral adaptability of cooling coatings on environment-side water-to-air radiators. The COP of a practical system with the actual coating is only maximally 8.0% smaller than that of the ideal system. Under the current worst energy crisis, this study can provide a novel application way of cooling coatings and a new cooling source for HP systems, with advantages of water saving, energy saving, and high energy efficiency.

A dataset of horizontal and slope-parallel installation of radiometer to measure solar radiation components and turbulent energy flux at Maoershan station in 2016

Solar radiation is one of the key parameters driving carbon and water fluxes, as well as other types of terrestrial processes. Radiometers, the most commonly used instruments for measuring local-scale radiation and albedo, are typically installed horizontally according to meteorological observation standards. However, under sloping terrain conditions, their hemispherical view and the surface receiving or reflecting radiation are not vertical. This discrepancy often results in a daily phase shift between net radiation and turbulent energy fluxes. Montane region accounts for one-quarter of the total global land surface area, yet few studies have quantified and corrected the errors resulting from horizontal installation of net radiometers in these areas. The dataset compiled in this paper were solar radiation and turbulent energy flux data measured by horizontal and slope-parallel radiometers in the secondary forest of the Maoershan Forest Ecosystem Research Station in Heilongjiang from March 17, 2016, to April 3, 2017. The data included incident and reflected shortwave radiation, longwave radiation, photosynthetically active radiation, as well as albedo, solar elevation angle, clear sky index, sensible heat flux, latent heat flux, and soil surface heat flux data. These data were stored in half-hour intervals, with radiation and turbulent energy flux data coverage rates during the growing season (May 3, 2016 to October 10, 2016) of 100% and 81.3% respectively. This dataset can provide original data for evaluating the impact of radiometers installation methods on the measurement of radiation components and albedo in montane regions, which not only help to correct historical data or construct more accurate models, but can also provide methodological references for studies related to carbon, water, and energy fluxes.

Experimental Research of Triple Inertial Navigation System Shearer Positioning.

In order to improve the positioning accuracy of shearers, the overground experimental device based on the positioning model of TINS (Triple Inertial Navigation System) was built. The influence of TINS installation parameters on positioning accuracy was discussed through two sets of experiments: the inter-INS (Inertial Navigation System) distances influence experiments and the tri-INS plane spatial position influence experiments. The results show that the positioning accuracy of the shearer is improved to a different extent under the two sets of experimental conditions. When the inter-INS distances are 0.2 m, the positioning accuracy is the highest and the positioning accuracy improvement effect is also the best. When the negative plane α3 is 45°, the positioning accuracy is the highest, and the positioning accuracy improvement effect is also the best. The analysis shows that the main factor affecting the positioning accuracy is the precision of the evaluated values outputs of TINS from EKF (Extended Kalman Filter). Considering the positioning accuracy, equipment installation convenience and so on, the optimum installation parameters are 90° (horizontal installation) α3 for the positive plane and 0.2 m inter-INS distances.

Experimental and Numerical Optimization Study on Performance of Phase-Change Thermal Energy Storage System

Promoting the use of solar energy resources has always involved the challenges of instability and supply–demand mismatch. The key to solving these issues is to efficiently store and utilize solar energy resources using high-performance heat storage devices. This study designed a high-performance shell-and-tube phase-change thermal storage device and established a numerical model using ANSYS software to summarize the device’s dynamic melting law. To verify the accuracy of the numerical simulation, a performance testing platform for the phase-change thermal storage device was built to investigate the impact of various factors, such as the inlet water temperature, inlet water flow rate, type of heat storage, and initial temperature of the device, and to reveal the change law of the device’s performance. The results show that the inlet water temperature has the most significant impact on the device’s heat storage and release performance. When the device’s heat storage or release is used for heating, changing the inlet water flow rate has a weak and limited effect on the device’s performance. However, when the device’s heat release is used to provide domestic hot water, increasing the make-up water temperature and reducing the inlet water flow rate can significantly improve the device’s effective heat release. Furthermore, based on the experimental validation of the model’s correctness, this study further simulated and studied the impact of different factors on the device’s heat storage process to optimize its structural design and provide technical references for the device’s actual operation and installation. The results show that the placement of fins has a negligible effect on the performance of the heat storage device while reducing the fin spacing and increasing the fin thickness can significantly improve the melting efficiency of the phase-change material (PCM). Additionally, the heat storage characteristics of the device are significantly better in the vertical installation mode than in the horizontal installation mode. This study provides theoretical guidance and technical references for the design and use of phase-change thermal storage devices.

An Introduction to Horizontal Directional Drill Installation of High-Voltage Transmission Lines and Other Duct Banks: Improving on Conventional Overhead Transmission Lines

Horizontal Directional Drill (HDD) installation of high-voltage (HV) transmission has proven practical, and in some cases, less costly than traditional overhead options. Petrochemical facilities located on waterways provide excellent opportunities for underwater HDD-installed transmission lines. These designs can provide significant safety advantages as well as improve system reliability. They eliminate the height restrictions associated with overhead lines, reduce air traffic obstructions, and reduce the weather-related concerns typically associated with traditional overhead transmission lines, especially highly elevated transmission line crossings over waterways. They also offer significant opportunities when expanding existing facilities and designing for Prevention through Design by eliminating the overhead transmission and their associated contact risks throughout the life of the installation. Each HDD-installed transmission line is different and can create significant challenges; however, the benefits associated with this technology can significantly outweigh the effort. This article reviews some of the challenges associated with long, high-capacity transmission line installations, along with their associated solutions as incorporated in previous projects. This article does not cover the smaller and shorter HDD installations typically associated with electrical distribution commonly used to cross streets, highways, or feed commercial facilities.

Experimental study on performance of different local radiant cooling schemes

Energy consumption from building cooling is critical for the development of nearly-zero energy building. The indoor zone control of local cooling strategy has been proposed to address this problem. In this study, the application performance of different layout scheme of local radiant cooling was experimentally investigated to explore the optimum design strategy. A series of field experiments were conducted under eight layout schemes of the local radiant cooling considered height, horizontal installation zone, and area of the radiant terminal. The obtained results indicate that in the personnel activity zone (below 2.0 m), local radiant cooling can satisfy the thermal comfort requirements of the occupant. The installation zone has an obvious influence on the room thermal characteristics, whereas the influence from the area was limited. The thermal stability and uniformity of the indoor environment can be improved by modifying the layout of the low and outer zone for the radiant terminal. Increasing the area of the radiant panel is inefficient for the improvement of room thermal characteristics and indoor thermal comfort. The main ranges of the cooling capacity are 115–125 W/m2 for different layout forms of the local radiant terminal and the cooling capacity can be increased by 7%. The layout scheme for the radiant terminal with the outer and low zone can effectively improve the stability of the terminal cooling capacity. Results suggested that the layout scheme of both outer and low zone for the local radiant terminal is crucial to improve the thermal comfort and cooling efficient.

Numerical Simulation of an Indirect Contact Mobilized Thermal Energy Storage Container with Different Tube Bundle Layout and Fin Structure

The great development of energy storage technology and energy storage materials will make an important contribution to energy saving, reducing emissions and improving energy utilization efficiency. Mobile thermal energy storage (M-TES) technology finds a way to realize value for low-grade heat sources far beyond the demand side. In this paper, an indirect-contact M-TES container is studied using the computational fluid dynamics (CFD) method. By optimizing the heat exchange tube bundle layout and the installed fin structure of the shell and tube type M-TES container, a method of enhancing the charging and discharging efficiency is identified. The peripheral distribution mode of the heat exchanger tubes improves the efficiency of heat charging by 12.6% compared with the traditional uniform layout. The installation of the Y-shaped fins can improve the heat charging efficiency by 8.3%, better than straight fins. Compared with the horizontal installation of Y-shaped fins, the vertical installation of Y-shaped fins is preferred to improve the heat charging efficiency of the M-TES container.

Aheat transfer and fluid flow characteristics in a TBHE based on constructal design : An overview

With the beginning of the industrial revolution in the eighteenth century, ICE, refrigeration equipment and power stations developed. All of the above devices use TBHE. The important thing is the recent increase in energy demand, which led researchers to find optimal solutions to save the largest amount of energy. The objective of this review can be summarized in the research published in the field of TBHE of all kinds. In order to improve the performance of the TBHE, two basic conditions must be met, the first is to increase the CHTC, and the second is to reduce the PD across the HE. In order to reach this goal, many influential variables must be studied, including pipe diameters and shapes, vertical and horizontal distances, fins shape, and installation method. In addition to the arrangement of the tubes through the TBHE. It was in the form of IL or staggered, the type of flow that was stratified or turbulent. The most important variables affecting on the performance of HEs can be summarized in general. The shape of the pipes had a greater urgency in the process, as the flat pipes had better performance than the circular TBHE. Both the PD and the CHTC are a function of the Reynolds number, as both increase with the increase in the Reynolds number. Therefore, studies in this field must be intensified to obtain the optimal design TBHE, taking into account all the above variables.

Simulation and Optimization of Insulation Wall Corner Construction for Ultra-Low Energy Buildings

Approximately 40% of the overall energy consumption of society is consumed by buildings. Most building energy usage is due to poor envelope performance. In regions with cold winters, the corners of structures typically have the lowest interior surface temperature. In corners, condensation, frost, and mold are common. This has a substantial effect on building energy usage and residents’ comfort. In this study, the heat loss of corner envelopes is evaluated, and a suitable insulation construction of wall corners is constructed to increase the surface temperature of the envelope interior. Computational Fluid Dynamics simulation has been used to examine the heat transmission in a corner of an ultra-low energy building in this study. By comparing the indoor surface temperature to the soil temperature beneath the building, the insulation construction of wall corners has been tuned. The study results indicate that the planned insulation construction of wall corners can enhance the internal surface temperature in the corner and the soil temperature under the structure by approximately 8.5 °C, thereby decreasing the indoor–outdoor temperature differential and the heat transfer at ground level. In extremely cold places, the insulation horizontal extension belt installation can help prevent the earth beneath the building from freezing throughout the winter.

Emissions rate measurement with flow modelling to optimize landfill gas collection from horizontal collectors

A two-dimensional landfill gas flow model using the FEFLOW numerical code was developed to assess the potential improvement in landfill gas (LFG) collection and the reduction in greenhouse gas emissions at a landfill due to increases in the vacuum of horizontal collectors and/or installation of additional LFG collection infrastructure. A key calibration input parameter for the model, the fugitive methane emission rate from the study area, was measured using the airborne matter mapping method. The measurement showed that, at the time, the methane collection efficiency for the study area was approximately 37 %. The model indicated that increasing the vacuum of the existing collection system by 0.75 kPa could result in an improvement in collection efficiency from 37 % to 49 % within the selected study area. A similar increase of collection efficiency could be obtained by either doubling the number of horizontal collectors on a platform or installing a layer of permeable demolition waste on that level, without an increase in collection system vacuum. Combining the addition of collection infrastructure with an increase in collection system vacuum by 1 kPa was predicted to improve the collection efficiency for the study area to about 74 %.

Active distributed temperature sensing to assess surface water–groundwater interaction and river loss in braided river systems

Braided river systems are continuously changing environments, comprising heterogeneous gravel-forming meandering channels and bars, and dynamic surface water–groundwater (SW–GW) interactions. In alluvial aquifers associated with braided rivers, river leakage is volumetrically the most important source of groundwater recharge, yet neither the leakage process or recharge rates are well understood. Insights into how braided river systems recharge underlying braidplain aquifers during different hydrological conditions, and how this can be measured, is of critical concern for river management practices. Innovative field techniques using heat as a tracer can be applied to spatially map and quantify the temporal changes of SW–GW interaction and the processes and mechanisms of groundwater recharge for different flow regimes. Horizontal directional drilling was used to construct two 100 m long drillholes at a depth of ∼ 5 m beneath and perpendicular to the river channel at a field site on the Waikirikiri Selwyn River, South Island, New Zealand. The two drillholes were completed with a hybrid fibre optic cable, containing four multi-mode fibres and 2x18AWG copper conductors. A Silixa XT-DTS™ distributed temperature sensor unit combined with a Silixa Heat Pulse System, was used to collect active distributed temperature sensing (A-DTS) measurements along both cables. Results from two A-DTS surveys showed distinct temperature changes across the active river channel indicating spatial variability in river loss and preferential groundwater recharge pathways to the shallow braidplain aquifer. The average groundwater velocity was 14 m d−1. The average calculated river loss at the survey sites was 21 m3 d−1 m−1 compared to 25 – 26 m3 d−1 m−1 that was measured using differential flow gauging conducted during the same time period. The horizontal installation of the fibre optic cable and the A-DTS method provided valuable insights into SW–GW exchange between the Waikirikiri Selwyn River and shallow braidplain aquifer and how the river leakage rates varied spatially across the river channel.

Radiation and energy balance on a hillslope forest: horizontal versus slope-parallel installation of radiometer

Radiation and energy balance on a hillslope forest: horizontal versus slope-parallel installation of radiometer

Two types of installation of 3D‐printed zero tension lysimeter for soil leaching and water bucket model validation

AbstractQuantifying and analysing leaching water is essential to understand water and nutrient cycles and the vertical transport of elements through soils. Zero tension lysimeters (ZTLs) have been widely used to capture the soil solution leaching by gravity. This study designed and evaluated a 3D‐printed ZTL (ZTL3D) with specific characteristics and materials to quantitatively capture dissolved element fluxes. By 3D‐printing the ZTLs, we were able to include specific 3D structures and precise details in the design allowing installation of samplers from the surface rather than trenches, and thus avoiding the need for installation trenches to remain open. The ZTLs3D connect directly with the surface, do not depend on secondary collectors, can be installed at any depth, and samplers are easily retractable when dismantling the field set up. The material used, Nylon 12, was tested for dissolved organic carbon (DOC) release. The ZTL3D design was printed in two different external shapes while characteristics and internal design were identical. The difference in external shape was to study the effects of two contrasting types of installation: a cylindrical sampler for vertical installation (by soil coring from the surface) and a rectangular samplers for horizontal installation (from a pit or a trench wall). We installed them at different depths (2, 30 and 75 cm) in a forest soil and conducted rainfall simulation experiments. A water bucket model (WBM), created to calculate the water drainage fluxes that the ZTLs3D should collect, reproduced very well the variation in soil water content measured by soil moisture sensors installed adjacent to the ZTLs3D at 16, 30, 50 and 75 cm depth. Drainage fluxes simulated by the WBM showed that the vertical installation performed better at collecting water at all depths than the horizontal installation, but overall the ZTLs3D failed to collect the simulated amounts of drainage water. Nonetheless, the ZTLs3D did collect leachate water, enabling their chemical analysis. Combining the concentrations in the water collected by the ZTLs3D with the modelled drainage fluxes does allow estimation of DOC‐ and elemental leaching rates. This article presents the novel design of these two types of ZTLs3D because future improvements may result in better performance, and discusses their (dis)agreement with the modelled WBM fluxes.Highlights New 3D‐printed zero tension lysimeters (ZTLs) to capture element fluxes when installed vertically (cylindrical design) or horizontally (cubic design) were tested. Two external sampler shapes were created to optimise the installation process and both collected drainage water successfully. Vertical installation ZTLs worked better than horizontal types, but neither well‐reflected drainage fluxes simulated by water bucket model (WBM). Combined with WBM, both ZTL types provided a reliable method for quantifying nutrient and organic carbon leaching at different soil depths.