Bulk Heat Research Articles

Повышение долговечности переводников бурильных колонн электромеханической обработкой

Increasing the durability of drill pipe subs is a pressing problem, a solution to which will improve the efficiency of oil and gas companies when drilling wells. Outer diameter wear, tears on the end surfaces of couplings and the end surfaces of pins, as well as blemishes on external and internal conical rotary-shouldered connections are the most typical defects of the subs. A study and comparative bench tests of the 5135 steel subs with the Z-117 screw were conducted. Testing of the subs with hardening of the work surface by electromechanical processing was done in comparison with the base technology (hardening and high tempering) and carbonitriding. The drill pipe subs were manufactured and hardened by OOO Alexandrovsky Drilling Equipment Plant on the 1М63 machine modernized for electromechanical processing. The comparative bench tests of the drill pipe subs were conducted by OOO Kovrovsky Drilling Equipment Plant on the coupling makeup machine MC-4 by screwing on / unscrewing threaded connections, taking into account the Russian Federation standards and recommendations of the American Petroleum Institute API 7. Electromechanical processing, being one of the method of hardening by a concentrated flow of electric energy of industrial frequency, builds up a gradient layer with the hardness of 52–56 HRC on the surface of the drill pipe subs. The results of the screwing on / unscrewing tests of threaded connections with a toot-joint thread demonstrated high efficiency of carbonitriding and electromechanical processing (500 and more cycles) as a method of increasing hardness of the work surfaces and low efficiency of the current bulk heat treatment (up to 47–66 cycles).

Improving wear resistance of drill pipe sub thread by using final electromechanical surface hardening

Improving wear resistance of drill pipe sub thread is a vital task, and finding effective solution for it would much assist oil and gas companies to enhance well construction process. The report presents the results of comparative wear resistance tests for P147/147 and P133/133 subs of the top drive manufactured by OOO «NIGMASH» in Bashkortostan. The tests were performed by OOO «Tatburneft» holding company, a division of PAO «TATNEFT». Both, series and test subs were made from 40X2H4A steel. This report shows the results of metallographic studies and tests for improvement of the parts wear resistance, including the method of final electromechanical hardening (EMH) of the box and pin threads as compared with the conventional method of bulk heat treatment.The researches has developed the equipment, tools and technology for hardening of tool joint thread of drill pipe subs. The performed tests and studies aimed at enhancing efficiency of oil and gas well drilling. Their results are of much interest for oilfield operators, drilling and service contractors, as well as drilling subs manufacturers and repair companies.

Dead-end membrane distillation with localized interfacial heating for sustainable and energy-efficient desalination

Membrane distillation (MD) has the high potential to circumvent conventional desalination limitations in treating highly saline brines. However, the performance of MD is limited by its low thermal efficiencyand temperature polarization (TP) effect. Consequently, the driving force decreases when heat loss increases.In this study, we propose to minimize TP through localized heating where the thin feed channel was heated uniformly at the membrane-liquid interface without changing the properties of the membrane.This concept was further improved by implementing a new dead-end MD configuration. Investigated for the first time,this configuration eliminated circulation heat losses, which cannot be realized in conventional MD due to a rapid temperature stratification. In addition, the accumulation of foulants on the membrane surface was successfully controlled by intermittent flushing. 3-Dimensional conjugate heat transfer modeling revealedmore uniform heat transfer and temperature gradient across the membrane due to the increased feed water temperature over a larger membrane area. The increase of water vapor flux (45%) and the reduction of heat lossobserved in the new dead-end concept led to a decrease of the specific energy consumption by 57%, corresponding to a gain output ratio increase of about 132 %, compared to a conventional bulk heating, while preserving membrane integrity. A conjugate heat transfer model was deployed in ANSYS-Fluent framework to elucidate on the mechanism of flux enhancement associated with the proposed technique. This study provides a framework for future sustainable MD developmentby maintaining a stable vapor flux while minimizing energy consumption.

Design and development of a multipurpose portable heating setup for 45S5 bioglass and other ceramic samples.

As per the voices in the precision manufacturing industries, the machining of brittle materials such as glass and diamond is intricate owing to their thermo-mechanical properties. Machining of the brittle material with a localized heating method produced softness in the work material during the operation, resulting in microcracks and voids on the finished surface due to thermal stresses. Such pressing issues are solved by dry machining with bulk heating. The objective of the present research is to develop a sophisticated lab-made portable multipurpose heating setup for enabling various potent applications such as machining, elevated temperature scratch and indentation tests, and grinding, among other things, on hard and brittle materials. The mentioned process is done by softening the material with preheating of the samples. The overall dimensions of the developed setup are 105 × 150 × 53 mm3. This setup has been evaluated at different temperatures of the 45S5 bioglass sample surface up to 426 °C and is capable of holding and heating the samples.

Wood-Based Solar Interface Evaporation Device with Self-Desalting and High Antibacterial Activity for Efficient Solar Steam Generation.

The main challenges of a solar steam generation device based on biomass materials are complicated processing techniques and relatively low efficiency. To solve these problems, we reported a simple immersion treatment method by depositing polydopamine (PDA) and silver nanoparticles (AgNPs) on natural wood to prepare a novel solar interface evaporation device. Ag-PDA@wood exhibits a unique bilayer structure. The absorbance of the top light absorption layer is higher than 96% in a wide wavelength range (300-2500 nm). Owing to the synergistic photothermal effect between PDA and AgNPs, Ag-PDA@wood has ultrafast solar-thermal response (a temperature increase of 42.5 °C within 5 min under 1 sun), and more heat is located at the steam generation interface (the surface temperature is 45.1 °C). The natural wood layer at the bottom with low thermal conductivity provides sufficient water supply and reduces the bulk heat loss. A high evaporation rate of 1.58 kg m-2 h-1 is achieved using Ag-PDA@wood under 1 sun (1 kW m-2). Its evaporation efficiency reaches 88.6%. The results upon sewage treatment and seawater desalination indicate that Ag-PDA@wood has an excellent purification ability and self-desalting capacity. More importantly, when compared to traditional solar evaporators, Ag-PDA@wood exhibits high antibacterial activity. The result of this antibacterial experiment shows that this material almost completely kills harmful bacteria. Therefore, Ag-PDA@wood has a high application potential in seawater desalination and sewage purification, providing a significant incentive to solve the problem of insufficient freshwater supply.

Multifluid Modelling of Relativistic Radiation Hydrodynamics

The formulation of a universal theory for bulk viscosity and heat conduction represents a theoretical challenge for our understanding of relativistic fluid dynamics. Recently, it was shown that the multifluid variational approach championed by Carter and collaborators has the potential to be a general and natural framework to derive (hyperbolic) hydrodynamic equations for relativistic dissipative systems. Furthermore, it also allows keeping direct contact with non-equilibrium thermodynamics, providing a clear microscopic interpretation of the elements of the theory. To provide an example of its universal applicability, in this paper we derive the fundamental equations of the radiation hydrodynamics directly in the context of Carter’s multifluid theory. This operation unveils a novel set of thermodynamic constraints that must be respected by any microscopic model. Then, we prove that the radiation hydrodynamics becomes a multifluid model for bulk viscosity or heat conduction in some appropriate physical limits.

Heat transfer coefficients of additively manufactured tubes with internal pin fins for supercritical carbon dioxide cycle recuperators

This paper describes the measurement of convective heat transfer coefficients and friction factors for sCO2 flowing in additively manufactured tubes with internal pin fins at the US DOE’s National Energy Technology Laboratory in Morgantown, WV. The measurement procedures were validated by conducting benchmark tests with smooth stainless-steel tube and comparing the results with published correlations for Nusselt number (Nu) and friction factor. Over Reynolds numbers (ReD) ranging from 5 × 104 to 2.5 × 105, measured Nu was within 5% of the Dittus-Boelter correlation and measured friction factors were within 5% of the McAdams correlation for smooth tube flow.The candidate pin fin patterned pipes were additively manufactured (AM) at the Oak Ridge National Laboratory. The pins were circular or elliptical in cross-section and were printed at a 30° angle relative to the inner wall (to meet AM constraints). The pin arrangement was helical to promote enhanced heat transfer due to swirl flow. Pin length to diameter aspect ratio was 1.33, 2, and 8, while the pin diameter to tube diameter ratio was 0.188, 0.125, and 0.063. Tests were performed for ReD varying from 6.9 × 104 to 2.2 × 105 and at conditions equivalent to the low pressure (LP) outlet (8.69 MPa, 361 K) and the high pressure (HP) inlet (20.7 MPa, 350 K) of the low temperature recuperator (LTR) in an indirect sCO2 cycle. The Wilson plot technique was utilized to measure the bulk heat transfer coefficients.For the best performing design (tube A, pin length to tube diameter ratio: 1.33, pin diameter to tube diameter ratio: 0.19), the local heat transfer coefficient increased by 136% relative to the Dittus-Boelter correlation at the LTR low pressure outlet and 194% at the LTR high pressure inlet. These correspond to a 282% and a 271% increase in the product of the heat transfer coefficient and surface area (adjusted for fin efficiency) product, respectively. Large pressure drops across the test articles were observed. For Tube Design A, the average friction factor, across the range of ReD considered, was significantly larger than the McAdams correlation at both the LTR LP outlet and the LTR HP inlet. A thermal performance factor was utilized to express the ratio of material required to build a finned heat exchanger relative to a finless heat exchanger with the same heat duty and pumping power. Tube Design A was estimated to decrease the required heat exchanger material by 13%.

FP-TES: A Fluidisation-Based Particle Thermal Energy Storage, Part I: Numerical Investigations and Bulk Heat Conductivity

Renewables should become more continuously available, reliable and cost-efficient to manage the challenges caused by the energy transition. Thus, analytic and numerical investigations for the layout of a pilot plant of a concept called Fluidisation-Based Particle Thermal Energy Storage (FP-TES)—a highly flexible, short- to long-term fluidised bed regenerative heat storage utilising a pressure gradient for hot powder transport, and thus enabling minimal losses, high energy densities, compact construction and countercurrent heat exchange—are presented in this article. Such devices in decentralised set-up—being included in energy- and especially heat-intensive industries, storing latent or sensible heat or power-to-heat to minimise losses and compensate fluctuations—can help to achieve the above-stated goals. Part I of this article is focused on geometrical and fluidic design via numerical investigations utilising Computational Particle Fluid Dynamics (CPFD). In the process a controlled transient simulation method called co-simulation of FP-TES is developed forming the basis for test bench design and execution of further co-simulation. Within this process an advanced design of rotational symmetric hoppers with additional baffles in the heat exchanger (HEX) and internal pipes to stabilise the particle mass flow is developed. Moreover, a contribution bulk heat conductivity is presented to demonstrate low thermal losses and limited needs for thermal insulation by taking into account the thermal insulation of the outer layer of the hopper.

Improving Plasmonic Photothermal Therapy of Lung Cancer Cells with Anti-EGFR Targeted Gold Nanorods.

Lung cancer is a particularly difficult form of cancer to diagnose and treat, due largely to the inaccessibility of tumours and the limited available treatment options. The development of plasmonic gold nanoparticles has led to their potential use in a large range of disciplines, and they have shown promise for applications in this area. The ability to functionalise these nanoparticles to target to specific cancer types, when combined with minimally invasive therapies such as photothermal therapy, could improve long-term outcomes for lung cancer patients. Conventionally, continuous wave lasers are used to generate bulk heating enhanced by gold nanorods that have accumulated in the target region. However, there are potential negative side-effects of heat-induced cell death, such as the risk of damage to healthy tissue due to heat conducting to the surrounding environment, and the development of heat and drug resistance. In this study, the use of pulsed lasers for photothermal therapy was investigated and compared with continuous wave lasers for gold nanorods with a surface plasmon resonance at 850 nm, which were functionalised with anti-EGFR antibodies. Photothermal therapy was performed with both laser systems, on lung cancer cells (A549) in vitro populations incubated with untargeted and targeted nanorods. It was shown that the combination of pulse wave laser illumination of targeted nanoparticles produced a reduction of in the cell viability compared with control exposures, which demonstrates a possible application for minimally invasive therapies for lung cancer.

Effect of Heat Treatment in Pipe Processing Stage on Corrosion Resistance of Micro-Alloyed Steel Hot-Rolled Products

The effect of heat treatment on corrosion resistance of low-alloy pipe steels is investigated in relation to oilfield pipeline operating conditions. It is established that after pipe bulk heat treatment at 720 °C metal corrosion resistance increases, but at a lower temperature of 680 °C no significant change is detected. Analysis of the corresponding structural changes is performed and the main factors facilitating an increase in corrosion resistance are determined: cementite component spheroidization in the areas of pearlite or degenerated pearlite, and a reduction in dislocation density. The role of nanoscale precipitate type on pipe corrosion resistance is noted. It is established that at a higher processing temperature there is a larger fraction of ferritic precipitates. In contrast to interphase precipitates these particles do not adversely affect steel corrosion resistance.

Розробка індукторів для об’ємної та поверхневої термічної обробки зварних стиків залізничних рейок

Розробка індукторів для об’ємної та поверхневої термічної обробки зварних стиків залізничних рейок

Development of inductors for bulk and surface heat treatment of welded butt joints of railway rails

Development of inductors for bulk and surface heat treatment of welded butt joints of railway rails

Conditions for transition from a plume to a dome above a heated horizontal area

Natural convection flow above a heated horizontal area plays a major role in energy utilisation, indoor/outdoor thermal environment, city ventilation and pollutant dispersion. Such natural convection can present different flow patterns, and identifying the type of flow pattern is crucial for determining the bulk heat transfer coefficient. Water tank experiments were carried out to study two different forms of convection flow above a large area with different levels of background inversion. Two major flow patterns, i.e., plume-like and dome-like, were observed. The critical Froude number (Frc = 0.08) for the transition from plume-like to dome-like was identified. Plume flow developed when Fr > Frc and dome flow developed when Fr < Frc. The heat transfer coefficients in a stable environment were significantly lower than those in a neutral environment. The Nusselt number, which is a function of both the Rayleigh number Ra and buoyancy frequency N in a stable environment, was calculated and analysed. Natural convection develops over the built-up area due to the urban heat island effect. The diameter Dc of the critical built-up area was found to be 2.3 km under typical atmospheric background conditions for the transition from the plume-shape natural convective flow to the dome-shape. When atmospheric conditions are met, villages and small towns with diameters less than 2.3 km will probably present plume-like structures, whereas cities and megacities with larger diameters are most likely to form heat domes. Our findings may also have implications for city- and regional-scale urban planning.

Heat transfer performance of supercritical pressure CO2 in a non-uniformly heated horizontal tube

The convective heat transfer performance of supercritical pressure CO2 in a horizontal tube under three wall heat flux conditions was numerically investigated. More complex heat transfer characteristics under non-uniform heating conditions than that with uniform heat flux were observed. The more non-uniform the heat flux is in the circumferential direction, the worse heat transfer performance the CO2 has under most circumstances, except for relatively small or extremely high Reynolds number Re conditions. The heat transfer in most regions of the horizontal tube is enhanced, and the bulk heat transfer performance depends on the heat transfer in the top region of the tube mainly. For one-side heating conditions, it is better to place the heat source as closer as possible to the bottom of the tube for larger heat transfer coefficient, especially under relatively high heat flux conditions. When other conditions are the same, improving the Re shrinks the discrepancies of the heat transfer performance among tubes with different sides heated, which also indicates the weakening of the buoyancy effect. The ratio of the secondary flow number to the Reynolds number Se/Re could give good predictions for the buoyancy effect on the heat transfer performance in horizontal tubes with non-uniform heat flux.

Magnetic-field evolution with large-scale velocity circulation in a neutron-star crust

ABSTRACT We examine the effects of plastic flow that appear in a neutron-star crust when a magnetic stress exceeds the threshold. The dynamics involved are described using the Navier–Stokes equation comprising the viscous-flow term, and the velocity fields for the global circulation are determined using quasi-stationary approximation. We simulate the magnetic-field evolution by taking into consideration the Hall drift, Ohmic dissipation, and fluid motion induced by the Lorentz force. The decrease in the magnetic energy is enhanced, as the energy converts to the bulk motion energy and heat. It is found that the bulk velocity induced by the Lorentz force has a significant influence in the low-viscosity and strong-magnetic-field regimes. This effect is crucial near magnetar surfaces.

Thermal transport exceeding bulk heat conduction due to nonthermal micro/nanoscale phonon populations

While classical size effects usually lead to a reduced effective thermal conductivity, we report here that nonthermal phonon populations produced by a micro/nanoscale heat source can lead to enhanced heat conduction, exceeding the prediction from Fourier's law. We study nondiffusive thermal transport by phonons at small distances within the framework of the Boltzmann transport equation (BTE) and demonstrate that the transport is significantly affected by the distribution of phonons emitted by the source. We discuss analytical solutions of the steady-state BTE for a source with a sinusoidal spatial profile, as well as for a three-dimensional Gaussian “hot spot,” and provide numerical results for single crystal silicon at room temperature. If a micro/nanoscale heat source produces a thermal phonon distribution, it gets hotter than that predicted by the heat diffusion equation; however, if the source predominantly produces low-frequency acoustic phonons with long mean free paths, it may get significantly cooler than that predicted by the heat equation, yielding an enhanced heat transport beyond bulk heat conduction.

Study of the structural, mechanical and thermodynamic properties of the new MAX phase compounds (Zr1-xTix)3AlC2

The structural, electronic, mechanical and the thermodynamic properties of the MAX phases (Zr1-xTix)3AlC2 compounds have been investigated by using the full-potential plane-wave FP-LAPW method as implemented in the Wien2k code. The exchange-correlation (XC) energy of electrons was treated using the Perdew–Burke–Ernzerhof parametrization. The ground-state properties for the studied compounds were calculated and compared with available experimental and theoretical data. The calculated lattice parameters are reasonably comparable with experimental and theoretical results. The formation energy has been evaluated in order to determinate the stability of our compounds. The calculation of the electronic structure was predicted for the first time for the present MAX phase compounds. These results indicate that, all our compounds exhibit metallic behavior and this metallicity is due to the p-d hybridization. The elastic constants have also evaluated by the Hex-elastic package. The mechanical stability reveal that, all our compounds are stable mechanically. The bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio and Cauchy pressure were calculated and discussed in detail. Furthermore, the temperature and pressure effect on: Bulk modulus, Debye temperature and heat capacity at constant volume and constant pressure CV and CP, respectively have been investigated by the quasi-harmonic Debye model.

Fast collisional electron heating and relaxation in thin foils driven by a circularly polarized ultraintense short-pulse laser

The creation of well-thermalized, hot and dense plasmas is attractive for warm dense matter studies. We investigate collisionally induced energy absorption of an ultraintense and ultrashort laser pulse in a solid copper target using particle-in-cell simulations. We find that, upon irradiation by a$2\times 10^{20}~\text{W}\,\text{cm}^{-2}$intensity, 60 fs duration, circularly polarized laser pulse, the electrons in the collisional simulation rapidly reach a well-thermalized distribution with${\sim}3.5~\text{keV}$temperature, while in the collisionless simulation the absorption is several orders of magnitude weaker. Circular polarization inhibits the generation of suprathermal electrons, while ensuring efficient bulk heating through inverse bremsstrahlung, a mechanism usually overlooked at relativistic laser intensity. An additional simulation, taking account of both collisional and field ionization, yields similar results: the bulk electrons are heated to${\sim}2.5~\text{keV}$, but with a somewhat lower degree of thermalization than in the pre-set, fixed-ionization case. The collisional absorption mechanism is found to be robust against variations in the laser parameters. At fixed laser pulse energy, increasing the pulse duration rather than the intensity leads to a higher electron temperature.

Atmospheric Circulation on Black Widow Companions

Abstract We present a model for atmospheric wind circulation in binary millisecond pulsar (MSP) companions, showing how the optical light curve (LC) and radial velocities are sensitive to the wind flow, causing LC orbital phase shifts and asymmetries, as observed for several “spider” MSPs. Velocity widths of spectral lines offer additional opportunities for measuring surface wind speed. As examples, we fit optical data for the black widow pulsar J1959+2048 and the redback pulsar J2215+5135; the wind heating models (WH) are statistically strongly preferred over direct heating (DH) for both objects, although the latter is even better fit with a heated spot. In general, WH effects tend to increase the inferred orbital inclination i and decrease the inferred companion center-of-mass radial velocity amplitude K c ; both effects decrease the inferred neutron star mass. Even with such a decrease, we find large masses for the two neutron stars: and , respectively (for the modest surface speeds fit from the bulk heat flow; supersonic photospheric winds can slightly change these values). These are among the highest masses known, and our improved modeling increases confidence that the results are important for understanding the dense matter equation of state.

Feasibility of Estimating Turbulent Heat Fluxes via Variational Assimilation of Reference-Level Air Temperature and Specific Humidity Observations

This study investigated the feasibility of partitioning the available energy between sensible (H) and latent (LE) heat fluxes via variational assimilation of reference-level air temperature and specific humidity. For this purpose, sequences of reference-level air temperature and specific humidity were assimilated into an atmospheric boundary layer model (ABL) within a variational data assimilation (VDA) framework to estimate H and LE. The VDA approach was tested at six sites (namely, Arou, Audubon, Bondville, Brookings, Desert, and Willow Creek) with contrasting climatic and vegetative conditions. The unknowns of the VDA system were the neutral bulk heat transfer coefficient (CHN) and evaporative fraction (EF). EF estimates were found to agree well with observations in terms of magnitude and day-to-day fluctuations in wet/densely vegetated sites but degraded in dry/sparsely vegetated sites. Similarly, in wet/densely vegetated sites, the variations in the CHN estimates were found to be consistent with those of the leaf area index (LAI) while this consistency deteriorated in dry/sparely vegetated sites. The root mean square errors (RMSEs) of daily H and LE estimates at the Arou site (wet) were 25.43 (Wm−2) and 55.81 (Wm−2), which are respectively 57.6% and 45.4% smaller than those of 60.00 (Wm−2) and 102.21 (Wm−2) at the Desert site (dry). Overall, the results show that the VDA system performs well at wet/densely vegetated sites (e.g., Arou and Willow Creek), but its performance degrades at dry/slightly vegetated sites (e.g., Desert and Audubon). These outcomes show that the sequences of reference-level air temperature and specific humidity have more information on the partitioning of available energy between the sensible and latent heat fluxes in wet/densely vegetated sites than dry/slightly vegetated sites.