Commercial Pipe Research Articles

Printed, metallic thermoelectric generators integrated with pipe insulation for powering wireless sensors

The Internet of Things (IoT), coupled with advanced analytics, is poised to revolutionize manufacturing maintenance and efficiency. However, a practical route to powering these many IoT devices remains unclear. In this work, flexible thermoelectric generators (TEGs) are fabricated from low cost, screen printed silver and nickel inks before being integrated into a novel form factor device based on commercial steam pipe insulation. Through optimization of internal resistances and total device design, this 420-junction TEG device produces 308µW of power at a temperature difference of 127K. This is sufficient to power a temperature sensing circuit with wireless communication capabilities. In this report we demonstrate that, after an initial 4 h of charging, this TEG can power a standard RFduino microcontroller for 10 min while sending temperature readings every 30 s via Bluetooth Low Energy (BLE) to a cell phone. Additional optimization and scaling could further increase system efficiency and provide a viable route to powering an industrial wireless sensing network (WSN).

Energy saving into an absorption heat transformer by using heat pipes between evaporator and condenser

This study explores the feasibility of using heat pipes as heat exchangers inside an absorption heat pump type II (Absorption Heat Transformer) of a thermal capacity of 0.7kW. The heat pipe is a passive device to transfer heat because of low thermal resistance. A heat exchanger with heat pipes can be integrated between the condensation and evaporation processes of an Absorption Heat Transformer. This study has demonstrated that seven commercial heat pipes are required to condense 0.714kW and to reuse 0.177kW at 60°C in the evaporator, representing almost a third part of total heat supplied without heat pipes, provided that the generator temperature is over 55°C. Therefore, the efficiency of the Absorption Heat Transformer can be improved based on the concept of the Coefficient of Performance up to 20%.

Thermal performance of a selected heat pipe at different tilt angles

An attempt is made to design, fabricate and test a copper heat pipe with 12 mm diameter, 300mm length and thickness of 1mm with a heat input of 7.29W. Experiments were conducted with and without working fluid for different inclinations to assess the thermal performance of heat pipe. The working fluids chosen for the study are acetone and distilled water and are compared. The thermal performance of the heat pipe was quantified in terms of thermal resistance and overall heat transfer coefficient by measuring temperature distribution across the heat pipe. The heat pipe was aligned for different inclinations and an optimum tilt angle was found experimentally, validated the same with simulation result obtained by computational fluid dynamics analysis and also with a reference paper. The copper heat pipe is found to be effective when acetone is used as working fluid. The optimum inclination angle of heat pipe for maximum rate of heat transfer is found to be 60° for both the working fluids tested. Even the cost of the heat pipe fabricated is very less compared to the commercial heat pipes available in the market.

Automatic solid phase extraction of cadmium exploiting a multicommutated flow system previous ICP-MS detection: Application to tobacco samples

A miniaturized automatic sample pre-treatment system, based on multicommutated flow techniques, i.e. Lab on Valve (LOV) and Multisyringe Flow Injection Analysis (MSFIA) techniques, for cadmium determination by ICP-MS in organic samples is presented. The on-line extraction and preconcentration system retains the analyte on the resin (Dowex 50W-X8), followed of elution with 1molL−1 HNO3. The LOV-MSFIA system allows the fully automation of solid phase renewal, which shown a durability of 130 injections without its replacement. The optimal operating conditions were investigated using multivariate optimization tools. The detection limit was 0.05ng of cadmium, while the mass linear working range was 0.2–100ng. The precision of the proposed methodology was 2.4% (RSD, n=10) with a sample frequency of 9 injections h−1.The accuracy of the method was established by means of an organic matrix certified reference material (DORM-2), and the method has been successfully applied to different samples of tobacco (commercial cigarettes, pipe tobacco and tobacco leaves), obtaining recoveries between 90 and 105%. Main advantages of the proposed methodology are a minimal sample handling, good precision, high stability of the column and the versatility achieved by a variety of managed sample volumes.

Fatigue performances of the cracked aluminum-alloy pipe repaired with a shaped CFRP patch

To fully understand performances of the cracked aluminum-alloy pipe repaired with CFRP patches, a series of fatigue and quasi-static tests were conducted on commercial available type-7005 pipes. The pipe damaged with artificial cracks was wrapped around by shaped CFRP patches. Two bonding surface treatment methods, i.e. screw-thread and mechanical grinding, were proposed and applied in the repairing process. The fatigue life, residual stiffness and cyclic creep of the repaired specimen were tested, respectively. A fine numerical model was built in ANSYS and validated by the test data. The stress intensity factor was calculated by the developed FE model to reveal the failure mechanism of fatigue tests. The influences of patch length and number of layers were also evaluated and discussed. Test results showed that the fatigue life of the wrapped specimen with the screw-thread surface treatment was 22.18 times of that of the bare specimen, and 23.13% longer than that of specimen treated by mechanical grinding. It is concluded that the CFRP patch is capable of improving fatigue performances of the cracked aluminum-alloy pipe. The screw-thread surface treatment provides better fatigue effects than mechanical grinding. Optimized design in the shaped CFRP patch benefits achieving the best fatigue performances of repaired aluminum-alloy pipes.

Self-made microlysimeters to measure soil evaporation: a test on aerobic rice in northern Italy

Soil water balance researches aimed at improving crop water use efficiency often require the determination of soil evaporation. In this technical note, the performance of simple and cheap self-made microlysimeters for the measurement of soil evaporation was tested in an aerobic rice field managed by intermittent irrigation. Six microlysimeters obtained by cutting commercial PVC pipes and closing the bottom ends with caps were positioned in appropriate PVC outer casings installed into the soil. Three measurement campaigns (for a total of 11 measurement periods) were carried out in different vegetation cover conditions (rice development, rice maturity and after the crop harvest). Evaporation amounts were analysed with respect to climatic data, vegetation cover and soil water status and, finally, compared with the simulated results of a FAO Penman–Monteith “dual crop coefficient” model implemented with site-specific data. Evaporation rates in the three campaigns were closely dependent on the evaporative demand of the atmosphere ETo (R2 = 0.96, 0.98, 0.96), while the slope of the linear regression curve was strongly related to the vegetation cover (b = 0.29, 0.12, 0.94); soil water content, always rather high during the experiments, did not affect the evaporation rate. Measured and simulated evaporation amounts showed a close agreement: the linear regression was characterized by slope and R2 of 0.98 and 0.95, while RMSE and NSE indices were 0.15 and 0.94. From the tests conducted, we can conclude that the self-made microlysimeters presented in this note are affordable instruments for measuring soil evaporation, at least in temperate climate conditions.

Relationship between roughness height in use with Colebrook roughness function and the internal wall surface roughness parameters for stainless steel pipes

Flow tests were conducted on a total of 7 commercial stainless steel (SS) pipes of two sizes: 114.3 mm and168.3 mm O.D., and lengths of approximately 5 m, sourced from different manufacturers. The working fluid is a pipeline quality natural gas at a pressure range of 4700–5100 kPa(g), and flow rates resulting in Reynolds number (based on respective pipe I.D.) ranging between 8 × 106-23 × 106. The experimentally determined friction factor (λ) allowed calculation of the roughness function (RF), and determination of the effective roughness height (ks) in use with the Colebrook RF correlation. It was found that the commercial (SS) pipes exhibit different surface roughness characteristics that produce higher λ and higher ks than that of commercial carbon steel (CS) pipes having the same roughness parameter represented by the root mean square of the surface roughness element (Rq). It was found that the main contributor for the increase in λ or ks for the SS pipes over the CS pipes is the generally relatively low values of the roughness parameter RSm, which characterizes the frequency of the surface modulation along the length of the pipe surface. The lower the RSm, the higher the modulation frequency, and the higher λ or ks. A correlation between ks in use with the Colebrook RF or λ, and Rq was developed for commercial SS pipes in the form; ks = 2.2907Rq + 0.1029Rq2(both ks and Rq in μm).

Microstructural evolution of ASTM grade 91 after long-term creep testing

Modified 9Cr–1Mo steel (ASTM grade P/T91) is conventionally applied in the construction of high efficiency supercritical and ultra-supercritical boilers, reaching metal temperatures up to 600–610 °C. As a part of the characterisation process of commercial pipes, Tenaris has performed over the years several long-term creep tests, with duration up to over 100,000 h, for temperatures between 550 and 650 °C. Microstructural characterisation has been performed on broken specimens, including analysis of the state of precipitation after TEM imaging of extraction replicas. The evolution of M23C6 coarse carbides, and MX carbo-nitrides, as well as the nucleation of new phases, such as Laves and Z are described in this paper. Observations reveal Laves phase nucleation and growth peak at 600 °C, whereas almost no particles were observed after ageing at higher temperature; moreover, transformation of MX carbo-nitrides into Z-phase is also faster at 600 °C, and slows at higher temperature.

Effects of Measurement Conditions on Operating Limits of Solar Horizontal Heat Pipes

In this work operating limit measurements are presented for one self-fabricated and one commercial solar heat pipe at horizontal and small inclination angles. While for the self-fabricated test sample heat transfer is limited by entrainment, dry-out limit is observed for the commercial solar heat pipe. Operating limit measurements of the commercial solar heat pipe show good reproducibility, whereas the detected operating limit of the self-fabricated heat pipe varies drastically. When tested at slight inclination, high temperature oscillations indicating geyser boiling effects are observed for the commercial test sample. Finally, operating limit definitions given by the literature are discussed regarding their applicability for solar thermal applications.

Optimization of sewer networks using the mixed-integer linear programming

This paper introduces a method for optimizing sewer networks using the mixed-integer linear programming (MILP) for a given layout. The objective function is defined as the sum of the costs for pipe purchase, pipe-laying, and manhole construction expressed in linear terms and subject to minimum and maximum allowable slopes, velocities, and relative depths for both minimum and maximum sewage discharge rates in each pipe. Additionally, provisions are made as constraints or conditions to ensure that a minimum pipe cover is required, that pipe diameters do not decrease in the flow direction, and that pipes maintain a steady elevation at each manhole. All the non-linear constraints are transformed into the linear format. Pipe slope, binary variables accounting for commercial pipe diameters and average implemented depths have also been considered as decision variables. Finally, the performance of the proposed optimization method is evaluated in a benchmark sewer network from the literature.

Experimental Investigation Into the Relationship Between the Roughness Height in Use With Nikuradse or Colebrook Roughness Functions and the Internal Wall Roughness Profile for Commercial Steel Pipes

The relationships between the sand grain roughness height (ks) in use with Nikuradse or Colebrook correlations for the roughness function (RF) and the internal pipe wall roughness element described by the root-mean-square (RMS) of the roughness profile (Rq) for turbulent flow in pipes are experimentally examined. Flow tests were conducted on a total of 13 commercial steel pipes of two sizes: 168.3 mm and 114.3 mm outer diameter (OD). The aim was to provide further insight into relationship between ks and Rq, for use with either RF correlations. The tests were conducted on high-pressure pipeline quality natural gas in the range of Reynolds number (based on pipe internal diameter) of 9 × 106–16 × 106. For commercial carbon steel pipes, the relationship between ks and Rq was found in the form ks=1.306 Rq+0.078 Rq2 and ks=2.294 Rq (both ks and Rq in μm), for use with Colebrook and Nikuradse RF correlations, respectively. These correlations cover a wide range of Rq from 2.7 μm to 12.5 μm which is typically found in commercial carbon steel pipes. For stainless steel (SS) pipes, preliminary results indicate that other surface roughness profile parameters need to be employed to better define the values of ks for these types of commercial steel pipes.

Experimental Study of Water Hammer Pressure in a Commercial Pipe

Experimental Study of Water Hammer Pressure in a Commercial Pipe

Heuristic Optimization Model for the Optimal Layout and Pipe Design of Sewer Systems

The design of urban stormwater systems and sanitary sewer systems consists of solving two problems: generating a layout of the system and the pipe design which includes the crown elevations, slopes and commercial pipe sizes. A heuristic model for determining the optimal (minimum cost) layout and pipe design of a storm sewer network is presented. The hierarchical procedure combines a sewer layout model formulated as a mixed-integer nonlinear programming (MINLP) problem which is solved using the General Algebraic Modeling System (GAMS) and a simulated annealing optimization procedure for the pipe design of a generated layout was developed in Excel. The GAMS and simulated annealing models are interfaced through linkage of Excel and GAMS. The pipe design model is based upon the simulated annealing method to optimize the crown elevations and diameter of pipe segments in a storm sewer network using layouts generated using GAMS. A sample scenario demonstrates that using these methods may allow for significant costs saving while simultaneously reducing the time typically required to design and compare multiple storm sewer networks.

Production of seamless pipe in a pilger mill with new groove configurations

New groove configurations for the pilger mill reduce the nonuniformity of sleeve deformation on transition from the striker to the polishing section and enhance pipe quality. The rolling of 08X18H10Tsteel-Ш pipe blanks (produced by electroslag remelting) by the new method to obtain intermediate pipes is considered. Machining of the intermediate pipes—boring and turning—produces commercial pipe of diameter 530 and 630 mm corresponding to Technical Specifications TU 14-3R-197–2001.

Pipe Sizing of District Cooling Distribution Network Using Implicit Colebrook-White Equation

An implicit solution of Colebrook-White equation was used in calculating the friction factor for commercial steel pipes using Newton-Raphson method with Reynolds number ranging from 4.0 × 103to 1.3 × 107. Initial value for iterative friction factor estimation was based on expanded form of Colebrook-White equation for larger values of Reynolds number with tolerance value of 1.0 × 10-8. Numerical results were compared with known explicit solutions and iterative procedure proposed by Lester in which, their mean difference, root-mean square deviation, mean relative error and correlation coefficient were evaluated. Correlation coefficients equal to unity and overall mean relative error of 4.821 × 10-8were achieved for all fifteen (15) pipe cases with nominal diameters ranging from 100 mm to 1,500 mm when compared with iterative solution suggested by Lester. Student’s t-test for paired data was also used which yielded a calculated t-value of -5.406 × 10-4. Combining the piping network design criteria with the logical structure of friction factor calculation determines the pipe size of distribution network and defines the boundaries of chilled-water velocities at different pressure drop limits as a function of commercial steel pipe diameter according to ANSI B36.1.

Experimental heat transfer due to oscillating water flow in open-cell metal foam

While studies concerning heat transfer due to oscillating air (and few other gases) flow in metal foam are available, heat transfer due to oscillating water flow in metal foam has not been offered in the literature. This paper presents characteristics of heat transfer of oscillating water flow in commercial open-cell metal-foam pipe that were obtained experimentally, most likely for the first time. One main difference between gas and liquid flows in porous media is that dispersion is far more significant in the latter. Another difference is the length of the entrance region, which depends strongly on the Prandtl number. The trends in the cycle-averaged wall temperature, length-averaged wall temperature and cycle-averaged Nusselt number were similar to those for oscillating water flow in packed spheres and for oscillating air flow in aluminum, copper and graphite foams in a rectangular channel. For the higher flow frequency of the current study, the cycle-averaged Nusselt number was higher for higher flow displacement amplitude.

Comparison tests of cellular glass insulation for the development of cryogenic insulation standards

Standards for thermal insulation used in applications between ambient and low temperatures, below 100 K, require test data under relevant conditions and by different laboratories to develop data sets for the proper comparisons of materials. This critically important technology is needed to provide reliable data and methodologies for industrial energy efficiency and energy conservation. Under ASTM International's Committee C16 on Thermal Insulation, two standards have been issued on cryogenic thermal insulation systems. Thermal conductivity data sets have been taken using identical flat-plate boiloff calorimeter instruments independently operated at the Cryogenics Test Laboratory of NASA Kennedy Space Center (KSC) and the Thermal Energy Laboratory of LeTourneau University (LETU). Precision specimens of cellular glass insulation were produced for both laboratories to provide the necessary comparisons to validate the thermal measurements and test methodologies. Additional specimens of commercial cellular glass pipe insulation were tested at LETU to compare with the flat plate results. The test data are discussed in relation to the experimental approach, test methods, and manner of reporting the thermal performance data. This initial Inter-Laboratory Study (ILS) of insulation materials for sub-ambient temperature applications provides a foundation for further ILS work to produce standard data sets for several key commercial materials.

Analysis of friction factor reduction in turbulent water flow using a superhydrophobic coating

This study provides experimental and theoretical evidence that the coating of the inner surface of copper pipes with superhydrophobic (SH) materials induces a Cassie state flow regime on the flow of water. This results in an increase in the fluid's dimensionless velocity distribution coefficient, α, which gives rise to an increase in the apparent Reynolds number, which may approach the “plug flow state”. Experimental evidence from the SH coating of a classic unsteady-state flow system resulted in a significant decrease in the friction factor and associated energy loss. The friction factor decrease can be attributed to an increase in the apparent Reynolds number. The study demonstrates that the Cassie effects imposed by SH coating can be quantitatively shown to decrease the frictional resistance to flow in commercial pipes.

Effect of liquid oilfield-related media on slow crack growth behavior in polyethylene pipe grade materials

Polyethylene, as non-polar material, shows a high affinity especially to liquid non-polar aromatic and aliphatic hydrocarbons, and liquid hydrocarbons (LHC) to a certain extent migrate into the bulk material by sorption, leading to material plasticization (i.e., drop in modulus and yield stress). This paper aims to study the crack growth mechanism and failure behavior of commercial pipe grade materials when exposed to deionized water or LHC (90/10wt%i-octane/toluene) under the simultaneous application of cyclic loads. The results of the cyclic crack growth experiments with three PE 100 pipe grades, using cracked round bar (CRB) specimens and performed at two different temperatures (35°C and 60°C), are compared in terms of the specimen lifetimes, and the micro-modes and kinetics of failure by referring to concepts of fracture mechanics. Most importantly, while crack advance is preceded by crack-tip crazing in water, shear yielding takes place at crack-tips in the LHC environment.

The Effect of Soil Load on Fracture Behaviour of Three-Layer Polymer Pipe for Non-Pressurised Applications

Fracture behaviour of a three-layer polymer pipe subjected to nonhomogenous distribution of external pressure induced by soil embedding is studied in this paper. Both long term and additional short term loading is considered. Such loading induces tensile stresses in the inner pipe wall which can lead to crack initiation and further slow crack propagation. The material interface between a protective layer and the base pipe can contribute to crack deceleration and can prolong the residual lifetime of the pipe. The paper presents three-dimensional numerical analysis of a commercial three-layer pipe containing an internal semi-elliptical crack. The effect of soil load on the fracture behaviour of the cracked pipe is quantified and discussed.