Pipe Distance Research Articles

Optimization of cooling system parameters with temperature field of mass concrete during hydration

Embedded cooling pipe system is regarded as the primary means in mass concrete to control the temperature. The effects of three factors are investigated on the thermal field of mass concrete by the combination of measurement, theoretical analyze and numerical simulation in this paper, including cooling pipe spacing, pipe diameter and pipe arrangement. The results demonstrate that the peak temperature is reduced by the increase in both of the pipe distance and pipe diameter. The peak temperature is measured to decrease from 1 °C to 3 °C on the monitoring points, with additional 0.5 m of pipe spacing or 10 mm of pipe diameter. The serious influence is conducted by the pipe diameter on the temperature difference, and the selection of cooling pipe diameter is considered to balance multiple problems in the project necessarily. The serpentine arrangement is more widely used for better cooling and construction in the comparison of the circular arrangement. The results on the optimization of cooling system are utilized for the project to control the hydration heat accurately and reduce or even prevent the generation of cracks.

Optimization of Water Purification Infrastructures in Supiori Regency

Clean water is one of the important aspects that must be prioritized in urban planning. The higher the standard of living of the community, the need for clean water will also increase. However, the fulfillment of adequate clean water needs in Supiori Regency is still not optimal. Based on the Minister of Public Works Regulation No. 14/2010, the coverage of drinking water services in Supiori Regency is classified as poor, with a clean water service level of less than 50%. Optimization efforts are needed to optimize and distribute clean water services in Supiori Regency meet the target of clean water services and create a sustainable community life. The research method uses three types of analysis. First, the ratio of clean water services in the settlements of Supiori Regency was analyzed using a calculation method that refers to the standard of clean water needs and availability. Second, the analysis of clean water services was conducted based on community perceptions. Third, this study analyzed the factors that influence clean water services using multiple linear regression. Descriptive analysis was used to identify optimization steps. The results showed that the ratio of clean water services in South Supiori District only reached 30.38%, while in East Supiori District, it was lower, at 19.78%. Based on community perceptions, 93% of the population in South Supiori District and 75% in East Supiori District have not used the Water Supply System. Regression analysis shows that in Supiori Selatan District, factors affecting clean water services include pipe distance, community participation, and number of family members. In East Supiori District, the influencing factors are pipe distance, management, and maintenance of clean water. So, there are optimization efforts that can be done, among others, through mapping services based on regional conditions. For areas that are difficult to reach by SPAM services, the community can utilize the nearest water source to meet their clean water needs independently.

Three-dimensional convolutional neural network for leak detection and localization in smart water distribution systems

Smart meters such as advanced metering infrastructure (AMI) can significantly improve identifying realistic sized leaks in water distribution networks (WDNs). However, to date, detection/localization methods for AMI systems are extremely limited. In this study, to examine the benefits of using AMIs for leak detection within distribution network, a three-dimensional (3D) convolutional neural network (CNN) deep learning (DL) model is proposed that can account for temporally and spatially distributed information of pressures. The 3D CNN is tested for a real WDN in Austin using the realistic sized leaks (e.g., 3 L/s for 150-mm pipes) that are generated from hydraulic simulations. The model's performance is evaluated using detection probability, false alarm rate, and localization pipe distance metrics. In addition, the strength of using DL for leak identification is examined by comparing the CNN results with those from an optimization-based model. The 3D CNN performed better than the optimization model indicating that DL has advantages over conventional tools such as optimization methods. However, its adaptability may limit its use in some cases. Since DL can be significantly impacted by hydraulic simulation model, a way to handle modelling error must be determined. In addition, as network changes occur, retraining is required that may be time consuming and have difficulty with the number of failure conditions.

Development of a transient analytical method for multi-pipe earth-to-air heat exchangers with parallel configuration

A novel analytical model for calculating the thermal performance of multi-pipe earth-to-air heat exchangers is presented by considering soil thermal saturation as well as soil temperature fluctuations on the ground surface. The accuracy of the analytical model is validated using a three-dimensional numerical simulation. The proposed analytical model shows a great coincidence compared to the numerical simulation as well as already reported experimental data. Using this analytical approach, a three-pipe earth-to-air heat exchanger in realistic working conditions is simulated and the effect of the center-to-center distance of pipes on the outlet air temperature and averaged cooling capacity are also investigated. It is shown that while decreasing the distance between the pipes does not change the temperature of the outlet air in the initial working days, a reduction in the thermal performance is observed as the simulation proceeds. This can be attributed to the soil thermal saturation around the middle pipe. The average cooling capacity of the middle pipe reduces by 48%, 35%, 19%, 5%, 2%, and 1% with respect to a single-pipe earth-to-air heat exchanger system for the distance of 25, 50, 100, 200, 250 and 300 cm between the pipes, respectively. In addition, it is shown that increasing the air velocity through the pipes enhances the cooling capacity, especially for larger pipes distance. The cooling capacity of the earth-to-air heat exchanger is enhanced as a result of the increment in the soil thermal conductivity in such a way that the increment percentage is higher for smaller pipe distances. The appropraite distance between the pipes is also shown to be related to the soil thermal conductivity. It is shown that for soil with thermal conductivity of 0.5 and 2 W/m.K, the appropraite distance becomes 200 cm and 300 cm, respectively.

Conjugated non-Newtonian phase change process in a shell and tube heat exchanger: A parametric-geometric analysis

The present study aims to better knowledge of the phase change process in shell and tube heat exchangers in the presence of thick tubes, porous medium, and Carreau- Yasuda non-Newtonian fluid. It is the first time that this combination has been presented in the literature. It is believed that considering the phase change process of RT-35 as a Carreau-Yasuda non-Newtonian one in the presence of porous medium and copper pipes can create a challenge in the field. The continuity and momentum equations along with the horizontal and vertical directions, the heat equation for RT-35 as a non-Newtonian Carreau–Yasuda fluid, and the heat equation for thick tubes were determined and transformed into their non-dimensional forms, which were then solved using the finite element method. The effects of non-dimensional numbers such as Stefan number, porosity parameter, Rayleigh number, and Effect of rheological behavior of fluid have been determined. Reaching better performance via using porous medium and center- a to- center distance of double pipes, as well as a number of the pipes, are the ideas to conduct the present study. The results were reported as the average Nusselt number, melting fraction of the PCM, the average velocity of the non-Newtonian fluid, streamlines, and isotherms, all as functions of non-dimensional time. The results indicated that higher values for the porosity parameter led to lower heat transfer rates, which in turn weakened the PCM melting front. It was also found that changing the center-to-center distance between the hot tubes influenced melting front propagation.

Analysis of Heat Dissipation Performance of Battery Liquid Cooling Plate Based on Bionic Structure

To provide a favorable temperature for a power battery liquid cooling system, a bionic blood vessel structure of the power battery liquid cooling plate is designed based on the knowledge of bionics and the human blood vessel model. For three different discharge rates of 1C, 2C, and 3C, FLUENT is used to simulate and analyze the heat dissipation performance of the liquid cooling plate with a bionic vascular structure. The influence of the pipe distance (A1 and A2) at the coolant outlet, the thickness of the liquid cooling plate, the inner pipe turning radius R of the pipe in the channel, and the mass flow of coolant on the heat dissipation performance are studied. The results show that the pipe distance (A1 and A2), plate thickness, and inner pipe turning radius R have significant effects on the heat dissipation of the liquid cooling plate, especially under a 3C discharge. In addition, the channel area at the coolant outlet also has great influence on the heat dissipation performance of the liquid cooling plate, and the variable width optimization of the channel area at the outlet greatly improves the heat dissipation performance of the liquid cooling plate. Increasing the inlet mass flow rate can improve the heat dissipation capacity, but at the expense of a pressure drop. A verification experiment is designed for 3C discharge. The results show that the error between the experiment and simulation results is within 9.8%; therefore, the simulation is accurate, and the liquid cooling plate has a significant heat dissipation effect.

Model-free Sensor Placement for Water Distribution Networks using Genetic Algorithms and Clustering*

This paper presents a model-free methodology for the placement of pressure sensors in water distribution networks (WDNs) with the aim of performing leak detection/localization tasks. The approach is based on a custom genetic algorithm (GA) optimization scheme, which considers a population whose individuals are binary vectors encoding the network nodes with/without sensors. The optimization process pursues the minimization of a distance-based metric, computed considering the pipe distance from the possible sensors to the complete set of nodes of the network, hence removing the necessity of a hydraulic model of the WDN. The methodology is completed by means of an iterative clustering technique that seeks the enhancement of incoming individuals. The proposed methodology is tested over a well-known case study, L-TOWN from the BattLeDIM2020 challenge, in order to assess its performance.

Incremental upgrading sensor placement methodology: Application to the leak localization in water networks

This paper presents a new methodology for sensor reallocation in large scale-systems considering fault isolation purposes. From an initial set consisting of a limited number of sensors already installed in certain locations of the system, the proposed methodology produces a new sensor placement where some of the sensors are strategically reallocated in different but available places of the system. The procedure is posed as an optimization problem where the performance index is specific of the fault isolation method to be used. The algorithm that solves the problem is an incremental upgrading approach based in the Sequential Forward Floating Search algorithm and it combines a forward phase (where sensors are added sequentially) with a backward phase (where sensors can be individually removed from the original sensor placement). The proposed methodology is illustrated by means of its application to the problem of leak localization in Water Distribution Networks (WDN), where the particular placement of the pressure sensors has a great impact in the ability to isolate the leaky node. Also, since only a limited number of pressure sensors can be installed in some nodes, space interpolation techniques must be used to estimate the pressure in the other network nodes. The performance of the localization process is measured in terms of pipe distance from the estimated leaky node candidate to the real leaky node. The proposed methodology is applied to two District Metered Areas of the WDN of a metropolitan area of Spain, in simulation and using real measurements and leak scenarios.

Numerical analysis on surface settlement in parallel rectangular pipe jacking construction

In recent years, rectangular pipe jacking technology has been gradually applied in urban underground engineering. Based on a parallel rectangular pipe jacking project, a three-dimensional finite element model is established for numerical analysis, and the surface settlement caused by rectangular pipe jacking construction is studied. The research shows that the pipe jacking construction has the most obvious impact on the soil above the pipe jacking axis, and when the clear distance between parallel rectangular pipe is 1D (D indicates the pipe inner width), the main influence range of pipe jacking construction on soil mass is about 1D along the longitudinal direction of pipe jacking. With the increase of parallel rectangular pipe distance, the surface settlement trough becomes wider and the maximum surface settlement decreases. The main influence range of parallel rectangular pipe jacking construction at the outside of the pipe jacking is about 1D~1.37D along the lateral direction. When the pipe distance is greater than 2D, the interaction between parallel pipe jacking is weak, and the influence range at the outside of pipe jacking is almost the same as that of single pipe jacking construction. The research results can provide a reference for the design and construction of similar pipe jacking projects.

Comparison of long-term performance and initial cost of a horizontal ground source heat pump with an air source heat pump in hot regions

Ground source heat pumps (GSHPs) have received much attention due to their high coefficient of performance (COP). In these systems, the ground is used as a sink/source for heat pumps and the heat transfers between the ground and the heat pump is performed by the ground heat exchanger (GHE). In this study, the long-term performance and initial cost of these systems have been compared with conventional air-source systems in a hot region. To evaluate the performance of the GSHP, using fluent software, numerical modeling of a linear horizontal GHE was carried out in Bandar-Abbas. Also, the effect of various system operating parameters, i.e., length, distance, buried depth, and diameter of GHE pipes have been studied. According to results, the five-year COP and exergy efficiency of GSHP systems is 19.9% to 24.30% and 5.95% to 6.55%, respectively, more than that of the air-source system. However, 1.2 to 2.5 million Tomans is needed as the installation cost for each kW of maximum building load per year. Also, it is demonstrated that by reducing the length of the GHE, the initial cost is reduced, and the performance increases, the pipe spacing is the most important factor in the required ground surface, the depth has the most impact on the initial cost and the performance, and the pipe diameter does not affect the system performance.

Numerical simulation of heat transfer performance and reliability design of road snow-melting system based on inorganic heat pipe

In order to study the optimal design parameters of the heat pipe system in the heat pipe snow-melting road structure, a finite element analytical model of the snow-melting road is established based on the heat transfer theory. And based on the analysis of internal heat transfer and surface convective heat transfer of the road, the author set suitable boundary conditions of temperature field according to the actual situation of the road pavement and made quantitative research on the influence of factors such as the evaporating section burial depth and arrangement distance of the heat pipe on the pavement temperature field. The results show that the optimal arrangement distance of the heat pipes is 300-500mm, and when the heat pipe distance is 500mm, the temperatures of the road surface increased slowly, the isotherm of 0°C will no longer continue, and the snow-melting time would become longer; heat pipe burial depth should be determined according to the road structure, the shallower the burial depth the better the snow-melting effect..

Mitigating effect of embankment to adjacent pipe with CDM columns

Pipelines are valuable infrastructures that covering a large area or expanding to long distance for the transporting function. This leads to the variety of loads and effects applied on such buried structures. A thread to pipeline integrity is the construction of the embankment on the soft soil which leads to the displacement of the pipe adjacent to the slope. This displacement will effect to the increase of internal force or causing failure of the near-by pipes. The use of concrete pile to improve the soil properties may be a solution; however, the cost for this is expensive. To propose an alternative solution for the problem, this study uses a system of cement deep mixing, CDM, columns as the solution for protecting the pipe. A simple 2D Finite Element, FE, model using Plaxis software has been established based on the equivalent soil approach which considering the CDM columns and their surrounding soil as an unified soil. The effectiveness of the proposed solution has been numerically investigated and proven. The lateral displacement of pipe and the maximum ring bending moment and other internal forces are significantly reduced with the appearance of the CDM columns. The selective parametric study has been implemented revealing the critical input variables are the distance of pipe to the slope and the length of the CDM column.

Optimization of ANFIS Network Using Particle Swarm Optimization Modeling of Scour around Submerged Pipes

In general, submerged pipes passing over the sedimentary bed of seas are installed for transmitting oil and gas to coastal regions. The stability of submerged pipes can be threatened with waves and coastal flows occurring at coastal regions. In this study, for the first time, the adaptive neuro-fuzzy inference system (ANFIS) is optimized using the particle swarm optimization (PSO) algorithm, and a meta-heuristic artificial intelligence model is developed for simulating the scour pattern around submerged pipes located in sedimentary beds. Afterward, six ANFIS-PSO models are developed by means of parameters affecting the scour depth. Then, the superior model is detected through sensitivity analysis. This model has the function of all input parameters. The calculated correlation coefficient and scatter index for this model are 0.993 and 0.047, respectively. The ratio of the pipe distance from the sedimentary bed to the submerged pipe diameter is introduced as the most effective input parameter. PSO significantly improves the performance of the ANFIS model. Approximately 36% of the scour depths simulated using the ANFIS model have an error less than 5%, whereas the value for ANFIS-PSO is roughly 72%.

Research on layout optimization of freezing pipes based on numerical calculation of hydro-thermal model

In order to study the influence of seepage flow on the development of frozen curtain in the artificial ground freezing project and optimize the distribution of freezing pipes. A coupled hydro-thermal model base on Darcy law and thermal balance equation has established and verified by the model test. The result shows that it can effectively improve the efficiency, reduce the completed freezing time and strength of frozen soil curtain. And the best distance which is all gratefully acknowledged between freeze pipe in upstream and section of original design freeze pipes is 75% of the distance of freeze pipes. In the end, the influence range of one pipe in upstream will be 3∼4 times the distance of freeze pipes.

Implications of supplying district heat to a new urban residential area in Sweden

Here we analyze the cost, primary energy and CO2 implications of supplying district heat, considering different supply and return temperatures, to a new residential area in Växjö, Sweden. We explore four land exploitation alternatives consisting different types of buildings with various heated floor areas as well as occupancy densities and two levels of building energy efficiency, based on the Swedish building code and passive house criteria. The analysis shows that energy performance of the buildings and land exploitation alternatives strongly influence the annual heat demand and its profile, which steers the design of the local heat distribution network. Additionally, supply and return temperatures of district heat somewhat influence the design of the network. The distribution heat losses could be reduced by 25% and 50% if district heating systems of 65/30 °C and 50/20 °C, respectively, are used instead of a conventional 80/40 °C system. However, for the same land exploitation alternative, the local distribution heat losses are about the same whether or not the buildings are designed to meet the Swedish building code or passive house criteria, since the same pipe distance is required and the variation of pipe diameters is small. A 50/20 °C system increases electricity use to boost hot water temperature to avoid the risk of legionella bacteria, and this influences quantity of district heat supply, primary energy use and costs. Therefore, a 65/30 °C system appears to be more primary energy and cost efficient than a 50/20 °C system. Increased insulation of district heating network reduces heat losses but this is not cost effective due to increased investment cost. The results are similar whether or not the analysis is based on current energy supply or future renewable based energy supply. This study increases understanding of strategies for planning and designing new urban residential areas and their energy supply systems to reduce primary energy use as well as monetary costs, and to minimize the climate impacts of the built environment.

Research on double-outlet valveless piezoelectric pump with fluid guiding body

In order to address the performance limitations of valveless piezoelectric pumps caused by backflow, a double-outlet valveless piezoelectric pump with a fluid guiding body to weaken liquid backflow energy has been designed. The pump chamber introduces a streamlined fluid guiding body incorporated with a double-outlet structure. When the piezoelectric pump absorbs water, the liquid from the outlet violently collides at the tail end of the fluid guiding body. The liquid then flows through the two ports and collides at the chamber, thereby attenuating the backflow liquid energy. The mechanism alleviates the problem of backflow in valveless piezoelectric pumps. This work examines the relationship between the main structural parameters of double-outlet valveless piezoelectric pumps with a fluid guiding body and the resulting energy loss of the backflow liquid. The effectiveness of the dual-outlet structure to suppress backflow of valveless piezoelectric pumps is analyzed using a finite element method, and the optimal pipe distance and tail distance parameters of the piezoelectric pump are predicted through multiple sets of simulations. Finally, a series of prototypes within the parameters of this study were produced, and experiments were performed. The test results show that the energy loss of the backflow liquid affects the output performance of the piezoelectric pump. In the parameter range investigated here, increasing the energy loss of the backflow liquid improves the performance of the valveless piezoelectric pump. The piezoelectric pump was designed to have a flow rate of 167.8 mL/min with a Piezoelectric actuator diameter of 35 mm at an applied voltage of 210 V at a frequency of 49 Hz.

PENGARUH PEMANASAN BAHAN BAKAR MELALUI 2 PIPA TEMBAGA BERSIRIP RADIAL PADA UPPER TANK RADIATOR DAN PENAMBAHAN ETANOL PADA BAHAN BAKAR TERHADAP EMISI GAS BUANG MOBIL SUZUKI APV

<p><em>This research aims to : 1) Investigate the effect of heating fuel through radial finned copper pipe in the upper tank of the radiator exhaust emissions on cars Suzuki APV; 2) Investigate the effect of adding ethanol to the fuel pertalite against exhaust emissions on cars Suzuki APV; 3) Investigate the effect of heating fuel through radial finned copper pipe in the upper tank of the radiator and the addition of ethanol to the fuel pertalite against exhaust emissions on cars Suzuki APV; 4) Analyze the comparison between the results of the fuel mixture pertalite heating and heating fuel ethanol pertamax through two copper pipe to the exhaust emissions of the Suzuki APV. This research use you right experimental method with a comparative descriptive data analysis. The sample used is a Suzuki APV with G15A1D100006 machine number. Data were obtained from a large measurement exhaust emission levels CO and HC for 20 seconds at idle rotation with variations mix pertalite and ethanol as much as 0%, 5%, 10%, 15%, 20%, 25%, and 30% using the method without heating fuel and the use of heating fuel through a copper pipe finned radial variation fin spacing of 10 mm, 20 mm and 30 mm In the upper radiator tank. Data obtained from the research that is inserted into the table and displayed in a graph, and then analyzed. The results of this study were: 1) heating fuel pertalite in radial finned pipe through the upper radiator tank to the injection cars Suzuki APV can decrease the value of exhaust emissions of CO and HC;2) Addition of ethanol in fuel pertalite with higher levels of 0% to 20% decline in the value of exhaust emissions of CO and HC. Exhaust emissions of CO and HC to increase again in the levels of ethanolblending with levels of 25% and 30%; 3) heating fuel in a radial finned pipe through the upper radiator tank to the injection Suzuki APV car down the value of exhaust emissions of CO and HC. Value exhaust emissions lowest CO occur in the application of finned pipe distance of 10 mm with a mixture of 20% ethanol content of 19% and HC 0.3 by 2 24 to 33 ppm; 4) The value of exhaust emissions of CO and HC in blending ethanol content to 20% lower than the lowest value of the results of exhaust emissions of CO and HC pertamax pure with a value of 0.354% levels of CO and HC at 229.67 Ppm.</em></p>

Experimental Investigation of Soil — Structure — Pipe Interaction

In this study the stress behavior of buried pipes in cohesionless soil was investigated experimentally. The parameters investigated in the laboratory tests include embedment ratio of pipe, horizontal distance of pipe to footing and the position of pipe. Hoop stresses at four positions on the borders of the pipes were measured by strain gauges. The results indicated that a significant increase in bearing capacities and decrease in pipe hoop stress when embedment ratio of pipe and horizontal distance of pipe to footing were increased. Based on the results of the laboratory model tests, the embedment ratio of pipe and the position of pipe are the main parameters that affect the hoop stresses on pipe.

Energy performance and economic feasibility of energy segmental linings for subway tunnels

This study focuses on the analysis of the energy performance and economic feasibility of so-called tunnel energy segmental linings: an innovative technology that couples the structural support role of the tunnel lining with the heating-cooling role of the heat exchanger harvesting both shallow geothermal and aerothermal energies. The work is based on three-dimensional time-dependent thermo-hydraulic finite element analyses of a real case-study and presents a sensitivity investigation on the energy performance of energy segmental linings for a variation of the following design solutions: (i) pipe configuration, (ii) heat carrier fluid flow rate and (iii) pipe distance from the tunnel intrados. Selecting the smaller pipe diameter for a pipe layout perpendicular to the tunnel axis involves installing a configuration with the higher pipe length per segment and represents the optimal solution in terms of thermal power harvested per unit lining surface. Increasing the heat carrier fluid flow rate to increase the turbulence in pipes represents an effective approach to improve the energy performance, with a decreasing effectiveness for a successive increase of the heat carrier fluid flow rate. Decreasing the distance between the pipes from the tunnel intrados significantly improves the energy performance, with an increasing effectiveness for a successive increase of the heat carrier fluid flow rate. The previous design solutions markedly influence the capital investment and operation costs of thermal power plants resorting to energy tunnels. For the same site conditions but different design solutions, these plants may not be considered economically attractive, with the most profitable application that is not necessarily associated with the design involving the highest harvested thermal power via the geostructure. Based on the results of this research, energy segmental linings appear a breakthrough technology for the renewable energy supply of the built environment when properly analysed and designed.

Impacts of perforated sheet pipe installation on some paddy soil properties

Today, the world’s vision emphasizes the development of climate-adaptive agriculture for food security and provision of water with safe technology. Under extreme weather conditions, it is necessary to manage water effectively. We must not neglect drainage as a water management option for sustainable agricultural production. Specially designed perforated sheet pipe drains have been developed in Japan recently to control the underground water table and to upgrade croplands from lowlands to uplands. As soils with perforated sheet pipes installed could potentially improve soil aeration, and land conversion could also influence soil functions and properties, this study focuses on the importance of soil properties changed around perforated sheet pipes installed at a depth of 40 cm in former paddy soils. Using (3 × 3 × 2) factorial design with three replications, soils were sampled on farmland in the Japanese towns of Hisayama, Fukuoka and Usa, Oita, respectively, in 2017 based on three stream sites (upstream, midstream and downstream), three distances from the sheet pipe (center, 1 m and 2 m) and two soil depths of 10 cm and 25 cm, respectively. Thirteen potentially changeable soil properties were measured, and all recorded data were analyzed statistically by performing the F test. All means were also compared at least the 5% significantly different level. As the results, there was a major improvement in air-filled capacity and infiltration above the installed perforated sheet pipe. The nearer the sheet pipe, the more the soil bulked together, with the more significant increase in soil organic matter, and total carbonate content that promotes the formation of soil macropores, at 1 m of sheet pipe distance in the deep paddy soil layer. The increase in the porosity (f) of studied soils allows more water and air to pass through.