Робочий процес струминного насоса відзначається підвищеною імовірністю виникнення кавітації в його проточній частині, що суттєво знижує ефективність та обмежує поширення нафтогазових ежекційних технологій. На основі використання рівняння збереження енергії та неперервності потоку розроблена методика визначення граничних експлуатаційних параметрів свердловинного струминного насоса, які відповідають безкавітаційній роботі ежекційної системи за умови відносного обертання робочого середовища. Розрахункова схема напірної ежекційної системи представлена лінійними гідравлічними опорами бурильної колони і затрубного простору та місцевими опорами у вигляді робочої насадки струминного насоса і промивальних насадок долота. Використовуючи систему рівнянь Бернуллі записаних для характерних перерізів ежекційної системи встановлена відповідність між мінімальним значенням тиску в проточній частині струминного насоса, глибиною свердловини, витратою робочого потоку та діаметром робочої насадки. Відносне обертання змішуваних потоків враховано за допомогою коефіцієнта стиснення робочого струменя, величина якого залежить від параметрів циркуляційного руху змішуваних потоків. Мінімальне значення тиску в проточній частині струминного насоса прямопропорційно залежить від глибини свердловини і витрати робочого потоку та оберенопропорційно -від діаметра робочої насадки. Кавітаційна характеристика ежекційної системи представлена у вигляді залежності граничних експлуатаційних параметрів від величини кута нахилу встановлених в проточній частині струминного насоса направляючих елементів. При збільшенні кута нахилу направляючих елементів мінімальний діаметр робочої насадки струминного насоса зростає. Залежності максимально допустимої витрати робочого потоку та мінімально допустимої глибини розміщення насоса в свердловині відзначаються екстремальною нелінійною залежністю від кута нахилу направляючих елементів. Ключові слова: струминний насос, ежекційна система, контроль параметрів, кавітація, неперервність потоку, обертання потоку, траєкторя струменя.

One of the most frequently encountered numerical problems in scientific analyses is the solution of non-linear equations. Often the analysis of complex phenomena falls beyond the range of applicability of the numerical methods available in the public domain, and demands the design of dedicated algorithms that will approximate, to a specified precision, the mathematical solution of specific problems. These algorithms can be developed from scratch or through the amalgamation of existing techniques. The accurate solution of the full radial equilibrium equation (REE) in streamline curvature (SLC) through-flow analyses presents such a case. This article discusses the development, validation, and application of an ‘intelligent’ dynamic convergence control (DCC) algorithm for the fast, accurate, and robust numerical solution of the non-linear equations of motion for two-dimensional flow fields. The algorithm was developed to eliminate the large extent of user intervention, usually required...

Coupling of high fidelity component calculations with overall engine performance simulations (zooming) can provide more accurate physics and geometry based estimates of component performance. Such a simulation strategy offers the ability to study complex phenomena and their effects on engine performance and enables component design changes to be studied at engine system level. Additionally, component interaction effects can be better captured. Overall, this approach can reduce the need for testing and the engine development time and cost. Different coupling methods and tools have been proposed and developed over the years ranging from integrating the results of the high fidelity code through conventional performance component maps to fully-integrated three-dimensional CFD models. The present paper deals with the direct integration of an in-house two-dimensional (through flow) streamline curvature code (SOCRATES) in a commercial engine performance simulation environment (PROOSIS) wit...

This paper describes our eorts to compute convective heat transfer through gas-turbine blade-cooling passages. The in¯uence on the mean and turbulent ¯ow due to surface rib-roughness is the main focus. A number of turbulence models, of eective viscosity (EVM) and second-moment type, are applied to the computation of ¯ow and heat transfer through ribbed-roughened passages. Computations of ¯ow through a rib-roughened U-bend show that second moment closures are necessary in order to correctly reproduce the regions of ¯ow separation. Heat transfer computations through two-and also three-dimensional ribbed passages reveal that low-Re turbulence models are necessary and that a low-Re dierential stress closure yields thermal predictions that are superior to those of the low-Re EVM model. A dierential version of the Yap length-scale correction term, independent of the wall distance, is introduced to the dissipation rate equation and is found to improve the heat transfer predictions of the low-Re kÀ model.

This paper provides a comprehensive overview of the electricity supply situation in Nigeria, focusing specifically on enhancing the performance of industrial gas turbines, GE GT13E2 (Afam Power Plant owned by FIPL) in Port Harcourt. The study encompasses two primary aspects. Firstly, it involves an examination of the nominal operating conditions of a combined cycle system and explores their dynamic performance through advanced simulations. Secondly, the research introduces a supplementary burner into the combined system and conducts a comparative analysis, considering factors such as system efficiency and power output. The power plant configurations are simulated using Gasturb14. The analysis is carried out by establishing the maximum attainable temperature in the Heat Recovery Steam Generator (HRSG), which determines the number of stages of supplementary firing that can be implemented. The results presented in this paper unveil the substantial potential for power generation with the addition of supplementary burners, indicating a remarkable increase in power output, yielding approximately 187.444 MW. However, this significant boost in power generation comes with an associated trade-off, wherein the overall system efficiency experiences a reduction. From an economic perspective, the additional power generated by the afterburner translates directly into increased revenue from electricity sales. Considering the average residential electricity rate in the U.S. as of February 2023, the calculated additional revenue from the afterburner amounted to approximately $25,641.58 per hour.

Exergy based analysis for thermodynamic systems has become increasingly important in understanding the efficiency of energy-work conversion. Entropy generation, associated with the irreversibility in practical processes, decreases the available useful work, and the mechanisms responsible for the production differ significantly between premixed and nonpremixed combustion. In addition, unsteady combustion generates temperature fluctuations and when accelerated produces entropy waves – referred to as indirect noise. Prior research by the authors have considered the dynamics of entropy generation purely due to heat release for both premixed and non-premixed flames. However, for non-premixed flames where the diffusion-controlled processes are important, transport terms must be considered for consistency. In this work, the entropy production mechanisms due to different sources are analyzed, firstly, by doing a mathematical study on the entropy transport equation and deriving the key forms of the source terms. Then reacting flow simulations are performed for the Sandia D flame, a well-documented configuration, for the numerical analysis of the transport equation. A range of operating conditions have been considered to illustrate the relative importance of different entropy source terms. Overall entropy production rate budget is calculated, and trends are observed for different operating conditions. In addition, across different sections of the flame, local entropy production is analyzed. Subsequently, reacting flow simulations are performed for the classical Burke-Schumann flame, a laminar nonpremixed flame, and the same analysis is carried out to completely gauge the trends of entropy production in non-premixed flames.

Loading flat coated specimens with tensile forces is a universal method to determine the nature of fracture of hard coatings in maritime applications. Such an approach allows the determination of the shear strength at the interfaces between layers and the cohesive properties. Thus, the authors studied the fracturing processes of plasma-sprayed yttria-stabilized zirconia two-layer coatings under the action of tensile forces. The results revealed cracking characteristics in the outer ceramic layer and delamination of flat metal specimens. An analytical method led to normal stress determination in the coating. It also exhibited shear stresses at the bond coat-substrate interface and the top coat-bond coat interfaces. The results include normal and shear stress distributions before and after fragmentation of the ceramic top layer. Tested substrate, the metal bond coat, and the ceramic top coat exhibit a modulus of elasticity of 196, 142, and 47 GPa, respectively. Engineers could apply t...

Ź ródła ciepła i energii elektrycznej/Sources of heat and electricity Cieplno-przepływowa analiza pracy elektrociepłowni geotermalnej opartej na obiegu ORC współpracującej z wymiennikiem typu Field Thermal-flow analysis of the operation of a geothermal CHP power plant based on the ORC cycle cooperating with a Field-type exchanger SŁAWOMIR WIŚNIEWSKI, TOMASZ KUJAWA DOI 10.36119/15.2024.12.2 W artykule przedstawiono analizę pracy elektrociepłowni geotermalnej z niskotemperaturowym obiegiem ORC zasilanym energią geotermalną pozyskiwaną za pośrednictwem głębokiego geotermalnego wymiennika typu Field. W analizowanym układzie elektrociepłowni geotermalnej z niskowrzącym obiegiem ORC ciepło na cele centralnego ogrzewania może być pozyskiwane z pary opuszczającej turbinę układu ORC lub bezpośrednio z wymiennika typu Field. Jak wykazała przeprowadzona analiza takie rozwiązanie umożliwia znaczną regulację strumienia ciepła na potrzeby ogrzewcze, poprzez zmianę zarówno strumienia masowego czynnika grzewczego, jak i jego temperatury. Proponowane rozwiązanie daje również możliwość funkcjonowania układu jako ciepłownia (tylko cele grzewcze), a w przypadku braku zapotrzebowania ciepła na cele ogrzewcze, jako elektrownia (tylko energia elektryczna). Takie podejście zwiększa elastyczność proponowanego rozwiązania i pozwala na lepsze wykorzystanie zasobów energii geotermalnej pozyskiwanej za pomocą wymiennika typu Field. W analizie układu elektrociepłowni geotermalnej uwzględniono zmienność parametrów pracy samego układu ORC dla trzech różnych czynników roboczych (R1234ze, R1234yf i R227ea) oraz zmienną charakterystykę wymiennika geotermalnego (zmiana strumienia wody). Słowa kluczowe: energia geotermalna, elektrociepłownia geotermalna, obieg ORC, czynnik niskowrzący, wymiennik typu Field The article presents an analysis of the operation of a geothermal CHP plant with a low-temperature ORC circuit powered by geothermal energy obtained via a deep geothermal Field exchanger. In the analyzed geothermal CHP plant system with a low-boiling ORC circuit, heat for central heating purposes can be obtained from steam leaving the ORC system turbine or directly from the Field exchanger. As the analysis shows, such a solution allows for significant regulation of the heat flux for heating purposes, by changing both the mass flow rate of the heating medium and its temperature. The proposed solution also allows the system to function as a heating plant (only for heating purposes), and in the absence of heat demand for heating purposes, as a power plant (only electricity). This approach increases the flexibility of the proposed solution and allows for better use of geothermal energy resources obtained using a Field exchanger. In the analysis of the geothermal power plant system, the variability of the operating parameters of the ORC system itself for three different working fluids (R1234ze, R1234yf and R227ea) and the variable characteristics of the Field heat exchanger (change of the water flow) were taken into account.

Abstrak- pt. kaltim Parna Industri (KPI) merupakan pabrik ammonia dengan kapasitas 1.500 MPTD. Kemurnian produk yang dihasilkan sebesar 99,95% berat. Proses yang digunakan pada PT. KPI adalah Haldor Topsoe Process. Bahan baku yang digunakan untuk memproduksi ammonia adalah gas alam (sebagai sumber H2) dan udara (sebagai sumber N2). PT. Kaltim Parna Industri memiliki dua unit utama yaitu unit proses produksi dan utilitas. Dalam unit proses produksi terdapat beberapa unit utama yaitu unit desulphurizer, reforming system terdiri dari primary dan secondary reformer, unit CO Converter yang terdiri dari High & Low Temperature CO Converter (HTS & LTS), unit CO2, unit methanator, dan ammonia converter. Pada unit utilitas memiliki unit-unit utama yaitu unit sea water intake, unit desalinasi, demineralisasi, daerator, Package Boiler, Water Heat Boiler, sea water cooling tower, waste water treatment system, klorinasi, STG dan emergency diesel denerator, N2 generator, instrument air, dan storag...

Nonlinear Model PredictiveControl (MPC) of Continuous Stirred Tank Reactor (CSTR) has been demostrated in this work. Optimal state estimation has been done using Extended Kalman Filter (EKF). Second order mathematical model for CSTR has been developed and further used for dynamic simulations. It is found that optimal control of temperature inside the CSTR is achieved better with the help of MPC strategy compared to conventional control strategies. It is seen that setpoint tracking performance using this optimal control strategy is satisfactory achieved.

Numerical computation has been applied to investigate the temperature field in a gas turbine combustion chamber. The simulation assumed that pressure imbalance conditions of air flow between primary and secondary inlets occur. The combustion chamber under study is part of a 70 MW gas turbine from an operating combined cycle power plant. The combustion was simulated with normal fuel-air flow rate assuming stoichiometric conditions. Under these conditions characteristic temperature and pressure fields were obtained provided equity of boundary conditions at air inlets applies. However, with pressure distribution imbalances of the order of 3 kPa between primary and secondary air inlets, excessive heating in regions other than the combustion chamber core were obtained. Over heating in these regions helped to explain what was observed to produce permanent damage to auxiliary equipment surrounding the combustion chamber core, like the cross flame pipes. It is observed that high temperatures which normally develop in the central region of the combustion chamber may reach other surrounding upstream regions by modifying slightly the air pressure. Microscope scanning of the damaged pipes confirmed that the material was exposed to high temperatures such as predicted through the numerical computation.

Exergoeconomic parameters of Ihovbor Gas Power plant were determined in this study. To achieve this, the exergy of each stream, the economic cost of the plant components, the exergetic costs of each stream and the exergoeconomic evaluation of each component were determined. The average exergy efficiency of GTs ONE, TWO, THREE and FOUR were found to be 59.32%, 60.83%, 59.80% and 60.38% respectively and it decreased with increase in ambient temperature. The exergy destruction cost was greatest in the combustor (average of 1596.175$/hr), the relative cost difference was greatest in the air compressor with an average ratio of 0.36585, the exergoeconmic factor of the gas turbine was greatest (91.84%) and the average cost of power generation was found to be $0.0162/kWhr. Exergoeconomic parameters can be used as tools for energy audit and determining the running costs of power plants and power generation.

This paper summarizes the proceedings of a panel session on recent technology advancements in photovoltaic genera¬ tion for central station applications in a utility environment. The panel session took place on July 18, 1983, during the 1983 Summer Meeting of the IEEE Power Engineering Society at the Bonaventure Hotel in Los Angeles, California. The panelists were: Roger Taylor of EPRI, who chaired the session and provided some introductory remarks highlighting photovoltaic (PV) research needs and goals; Paul Pittman of Westinghouse Electric Company, who outlined the technical and economic issues that need to be resolved before photovoltaic technol¬ ogy can expect widespread application; Spencer Carlisle of Southern California Edison Company (SCE), who summarized SCE's experience with photovoltaics and the role that this 85 WM 013-8

Objective: Major producers consider quality as a major criterion in decision making. Quality characteristics are affected by maintenance and repair decisions. In this study, a model is developed to determine significant measurements of production equipment affecting the quality of a continuous product to identify which measurements are more critical in terms of quality. Methods: Diversity of parameters affecting the quality and the delay until effects on quality come into view, are the main aspects of the issue. Genetic algorithm with a fitness function including prediction accuracy, convergence rate, and number of measurements is developed to obtain optimum set of measurements. Artificial neural networks are also used to evaluate the reliability and validity of the solutions. Results: The proposed model was applied and evaluated by a case study in unit 2, Parand Gas Turbine Power Plant. The results demonstrated the optimum set of measurements which are significantly related to quality characteristic. In addition, the available data demonstrating that the terminal equipment in production process has more significant effects on quality. Conclusion: The proposed model enjoys the capability of identifying the most important health measurements affecting the output quality of a continuous product in some limited steps of optimization algorithm by processing the history data from Condition Monitoring Process. With these significant measurements available, the decision makings in maintenance and repair can happen on the grounds of quality.

Purpose-The research aims to investigate the impact of thermo-mechanical aging on SBR under cyclicloading. By conducting experimental analyses and developing a 3D finite element analysis (FEA) model, it seeks to understand chemical and physical changes during aging processes. This research provides insights into nonlinear mechanical behavior, stress softening and microstructural alterations in SBR compounds, improving material performance and guiding future strategies. Design/methodology/approach-This study combines experimental analyses, including cyclic tensile loading, attenuated total reflection (ATR), spectroscopy and energy-dispersive X-ray spectroscopy (EDS) line scans, to investigate the effects of thermo-mechanical aging (TMA) on carbon-black (CB) reinforced styrenebutadiene rubber (SBR). It employs a 3D FEA model using the Abaqus/Implicit code to comprehend the nonlinear behavior and stress softening response, offering a holistic understanding of aging processes and mechanical behavior under cyclic-loading. Findings-This study reveals significant insights into SBR behavior during thermo-mechanical aging. Findings include surface roughness variations, chemical alterations and microstructural changes. Notably, a partial recovery of stiffness was observed as a function of CB volume fraction. The developed 3D FEA model accurately depicts nonlinear behavior, stress softening and strain fields around CB particles in unstressed states, predicting hysteresis and energy dissipation in aged SBRs. Originality/value-This research offers novel insights by comprehensively investigating the impact of thermo-mechanical aging on CB-reinforced-SBR. The fusion of experimental techniques with FEA simulations reveals time-dependent mechanical behavior and microstructural changes in SBR materials. The model serves as a valuable tool for predicting material responses under various conditions, advancing the design and engineering of SBR-based products across industries.

The Lean Premixed Prevaporized burner concept is now used in almost all new generation gas turbine to reduce flame temperature by operating near the lean blow-off limit. However, it is still an evolving technology: low flame temperature and homogeneous lean mixture compromise flame stability. Moreover, Vortex Breakdown phenomenon in reactive swirling flows is a very complex 3-D mechanism and its dynamics is not yet completely understood. Among the available measurement techniques to analyze such flows, Stereo PIV (S-PIV) is now a reliable tool to evaluate the instantaneous 3 velocity components in a plane (2D-3C). It is being used in this paper to analyze the reactive flow of a small scale atmospheric LPP burner (50 kW). The burner uses a Low Swirl configuration (Cheng et al. 2000) to stabilize the flame and reduce NO x emissions. The lifted flame also permits a good optical access to the whole recirculation zone. In this work, the flow is analyzed over a wide range of swirl and Reynolds numbers at different equivalence ratios. Flow statistics are presented for 1000 SPIV snapshots along with the measurement resolution limit. In both reactive and isothermal flow, stability diagram reveals the existence of two distinct topologies. Near field pressure measurements reveals the presence of peaks in power spectra, which suggests a strong coherence for almost all configurations. Algorithms have been developed to identify and track traveling coherent structures from the statistically independent SPIV realizations. Flow temporal evolution is reconstructed with an innovative POD-based method.

The manufacture and entrance into service of thin gage gamma-TiAl product has been hampered by the inherent low room temperature ductility of the material. In the present study a new approach was explored for the efficient manufacture of gamma-TiAl foil with improved ductility. The objective was to produce a very clean material (low interstitial content) with a highly refined, homogeneous microstructure placed in a fully lamellar condition. The processing route involved the use of RF plasma spray deposition of pre-alloyed powders, followed by consolidation via vacuum hot pressing and heat treatment. The approach took advantage of a deposition process which included no electrodes, no binders and high cooling rates. Results and discussion of the work performed to date are presented.

The thermal decomposition and heat transfer characteristics of gaseous, high-purity methane, several methane–hydrocarbon mixtures, and a typical natural gas fuel were evaluated using an electrically heated, stainless-steel tube test apparatus. Of several candidate heat transfer correlations, the Dittus–Boelter heat transfer correlation provided the best fit of the methane heat transfer data over the range of Reynolds numbers 10,000 to 215,000. The thermal stability (i.e., deposit formation) characteristics of the methane–hydrocarbon mixtures and the natural gas fuel were established and compared with the deposition characteristics of high-purity methane. Testing was conducted at wall temperatures up to 900 K (fuel temperatures to 835 K) for durations of up to 60 hours. Measurements of deposit mass indicated that there was essentially no deposit buildup for wall temperatures below 650 K. Deposit began to form at wall temperatures between 650 K and 775 K. Above 775 K, there was a rapi...

In this study, the heat transfer and friction characteristics of four different rib geometries-45 angled, Vshaped, W-shaped and M-shaped ribs in a two-pass stationary channel have been numerically investigated. The aspect ratio (Height to Width) of the cooling channel was 1:1 (square). The rib pitch-to-rib height ratio (p/e) and the rib-height-to-channel hydraulic diameter ratio (e/D h) were 16 and 0.125 respectively. The Reynolds number was varied from 20,000 to 70,000. For the computations, the Reynolds averaged NaviereStokes (RANS) equations were solved with the commercial software ANSYS Fluent using the realizable version of k-ε (RKE) model. The heat transfer results were benchmarked with experiments on a test rig with similar geometries and flow conditions. Detailed analysis of the flow characteristics in the two-pass channel was carried out so as to understand the interaction of the ribinduced secondary flows and the bend-induced secondary flows and their contribution to heat transfer enhancement. The heat transfer enhancement provided by V-shaped ribs was 7% higher than 45 ribs, 28% higher than W-shaped ribs and 35% higher than M-shaped ribs. However, the pressure penalty for Vshaped ribs was 19% higher than 45 ribs, 24% higher than W-shaped ribs and 28% higher than M-shaped ribs. On comparing the overall thermal hydraulic performance, V-shaped and 45 ribs were observed to perform significantly better than W-shaped and M-shaped ribs.

The multiple expansion reheating gas turbine proves to have a potential of good operational flexibility for the intrinsic capability of responding to variations in electric and thermal power demands without appreciable impact on efficiency. The present study deals with evaluation of the performance attainable in off-design operation, with power control obtained through changes in the first and second combustor firing temperatures and in the compressor intake air flow achieved by means of variable inlet guide vanes. Because of the important impact of the hot part cooling air flows on performance, the study includes also a hypothesis of controlling such flows in off-design operation through external means. The predicted off-design performance results superior in the hypothesis of external cooling air flow control, thus making such a system worthy of consideration for possible future developments of machines in this category. To evaluate the suitability of the multiple expansion reheating gas turbine in cogeneration applications, the electric efficienc and the electrical index have been taken into consideration. The capability of varying the reheating temperature represents an effective "la y of controlling the electrical index with good efficiencies in industrial cogeneration with strongly varying electric power and process heat requirements. With regard to the cooling air control through external means, implementation of such a more complex system seems to be avoidable at least when the gas turbine is intended specifically for application in cogeneration, because of its smaller impact on the overall efficiency of the system.

La Gasificación Integrada con Ciclo Combinando (IGCC) es una de las tecnologías de generación de potencia más promisorias para el aprovechamiento de recursos energéticos como carbón y biomasa. Los altos beneficios ambientales y la alta eficiencia de conversión energética ...

Forced excitation of a swirl stabilised methane/air flame by acoustic waves at atmospheric pressure has been characterised in order to show that the frequencies and amplitudes where self-excitation occurs, but the natural limit cycle takes effect, can be predicted from these data. Chemiluminescent emission was therefore recorded to measure the Flame Transfer Function (FTF), as the flame was acoustically excited by two loud speakers. The experiments covered a wide range of frequencies and amplitudes with particular emphasis on the FTF at high amplitudes of excitation, where a non-linear response is often reported. The system was modelled by the 1D thermo-acoustic element method, in which each acoustic element, such as a duct or a contraction, is described by a four-pole matrix. The flame is incorporated as another four-pole matrix that describes the measured flame transfer function. The solution of this set of equations without forcing predicts self-excitation frequencies and amplitu...

The propulsive performance of airbreathing pulse detonation engines at selected flight conditions is evaluated by means of a combined analytical/numerical analysis. The work treats the conservation equations in axisymmetric coordinates and takes into account finite-rate chemistry and variable thermophysical properties for a stoichiometric hydrogen/air mixture. In addition, an analytical model accounting for the state changes of the working fluid in pulse detonation engine operation is established to predict the engine performance in an idealized situation. The system under consideration includes a supersonic inlet, an air manifold, a valve, a detonation tube, and a convergentdivergent nozzle. Both internal and external modes of valve operation are implemented. Detailed flow evolution is explored, and various performance loss mechanisms are identified and quantified. The influences of all known effects (such as valve operation timing, filling fraction of reactants, nozzle configuration, and flight condition) on the engine propulsive performance are investigated systematically. A performance map is established over the flight Mach number of 1.2-3.5. Results indicate that the pulse detonation engine outperforms ramjet engines for all the flight conditions considered herein. The benefits of pulse detonation engines are significant at low-supersonic conditions, but gradually decrease with increasing flight Mach number. Nomenclature A = preexponential factor A e = area of engine exit plane c = speed of sound c p = constant-pressure specific heat e t = specific total energy F = instantaneous thrust F sp = specific thrust

High pressure processes (e.g. sustainable hydrothermal manufacturing of nanomaterials [1], supercritical water oxidation (SCWO) [2] and biomass hydrolysis [3]) require high operational conditions. Water at high pressure and temperature conditions improves kinetic, selectivity and efficiency of these processes but entail high-energy operational expenditure. Use of fluids at high operational conditions makes necessary to supply heat of high quality, as well as power. Because of this, it is necessary to study reasonable solutions for energy recovery and integration in order to achieve the energy self-sufficiency of the process and, if possible, the net power production and with a viable efficiency [4]. In this work, the energy integration of supercritical water oxidation process is being studied. One solution that has been recently proposed is the integration of supercritical processes with energy production in cogeneration or Combined Heat and Power (CHP) cycles. Cogeneration is defin...

Streszczenie: W pracy przedstawiono budowę, sposób działania oraz dane techniczne nowatorskiego rozproszonego strimera Seismobile. istotną rolę w strimerze Seismobile odgrywa sposób akwizycji danych pomiarowych, który decyduje o jego sprawności. konstrukcja strimera Seismobile umożliwia szybki montaż i demontaż jego elementów. Szybki montaż modułów pomiarowych umożliwia mocowanie magnetyczne. Moduły są automatycznie numerowane i lokalizowane przed każdym pomiarem. W strimerze moduły pomiarowe są bezpiecznie transportowane w stacji dokującej. konstrukcja zestawu pomiarowego, składającego się z czujnika zamontowanego na metalowej podstawie, zapewnia możliwie jak najlepsze (w sensie widma częstotliwości, niewielkiego tłumienia amplitud i minimalizacji rezonansów mechanicznych) przekazywanie drgań z podłoża gruntowego. Niskie położenie środka ciężkości zestawu pomiarowego zapewnia wystarczającą jego stateczność przy przemieszczaniu się strimera. Mobilny wzbudnik drgań pozwala w sposób bezprzewodowy wzbudzać sygnał i w sposób automatyczny przekazywać dane o czasie udaru i jego lokalizacji. Bezpośredni zapis cyfrowy rejestracji w wewnętrznej pamięci Flash modułów pomiarowych oraz duża dynamika przetwarzania A/c zapewniają wysokiej jakości dane. Sczytywanie bezprzewodowe zarejestrowanych danych w pamięciach Flash modułów pomiarowych i modułu wzbudnika w czasie ładowania akumulatorów w stacji dokującej po zakończeniu sesji pomiarowej zapewnia niezawodne archiwizowanie danych. innowacyjne cechy strimera Seismobile eliminują większość niedogodności dotychczasowych strimerów w zakresie akwizycji danych pomiarowych.

Heat transfer is of crucial importance to understand the conversion kinetics and the behavior during combustion of fuels such as plastics particles. In this work, the heat transfer onto single plastic resin particles (5x7 mm) by flames and a pulsed laser was studied by recording time resolved series of images with a high speed CCD (charge coupled device) camera. Images in the visible spectrum were recorded with a time resolution between 1 ms and 25 ms for a total duration of up to 60 s. A pulsed Nd:YAG laser was used in this study. For comparison, also a McKenna flat flame burner and a Bunsen burner operating on fuel-rich to fuel-lean CH4/air mixtures were used. The plastic resin particles were drilled and mounted horizontally on a thin wire. In the middle of the particle under investigation, a thermocouple was placed. For the experiments with the laser, the particle was suspended in room air (illuminated area 2 mm2, pulse duration 10 ms, pulse energy 5-30 J, laser wavelength 1064 n...

An extension of the Large Eddy Simulation (LES) technique to two-phase reacting flows, required to capture and predict the behavior of industrial burners, is presented. While most efforts reported in the literature to construct LES solvers for two-phase flow focus on Euler-Lagrange formulation, the present work explores a different solution ('two-fluid' approach) where an Eulerian formulation is used for the liquid phase and coupled with the LES solver of the gas phase. The equations used for each phase and the coupling terms are presented before describing validation in two simple cases which gather some of the specificities of real combustion chamber: (1) a one-dimensional laminar JP10/air flame and (2) a non-reacting swirled flow where solid particles disperse . After these validations, the LES tool is applied to a realistic aircraft combustion chamber to study both a steady flame regime and an ignition sequence by a spark. Results bring new insights into the physics of these complex flames and demonstrate the capabilities of two-fluid LES.

Libya's oil industry suffers from flaring, which wastes important resources, increases the emission of greenhouse gases and increases environmental damage. Flaring emits large amounts of carbon dioxide, Sulphur oxides, nitrogen oxides and hydrocarbons, in addition to other harmful effects on both people and the ecosystem. This research investigates the importance of flare gas recovery in Libyan refineries and the environmental advantages of flare gas recovery in promoting environmental sustainability by reducing flaring and adopting sustainable environmental practices. The study focuses on the strategies and technologies used to eliminate gas flaring globally by 2030. It examines annual estimates of gas flaring and gas flaring efficiency globally and nationally in Libya from 2019 to 2023. It highlights the importance of flared gas recovery and potential benefits through national and comparative research studies. It also highlights the environmental issues caused by these gases, showcases leading technologies and discusses their fundamentals, benefits and drawbacks.  The Flare Gas Recovery Unit (FGRU) is an advanced solution that converts flare gas into products such as LPG and compressed natural gas (CNG). Innovative Systems Advanced condensing systems, cryogenic separation systems, membrane filtration systems, biogas upgrading systems and hybrid systems play a critical role in torch gas recovery by enhancing purity, increasing recovery rates, saving energy, providing flexibility, cost effectiveness and environmental sustainability. Careful consideration of the challenges associated with this technology is essential during the design and operation of these systems

Częstą przyczyną drgań w pompach wirowych są pulsacje ciśnienia wywołane oddziaływaniem wirnika i kierownicy.
Mają one charakter periodyczny. Mogą przenosić się na tarcze wirnika i prowadzić nawet do ich uszkodzeń.
Wygodnym narzędziem określenia zbioru częstotliwości łopatkowych charakteryzujących te pulsacje jest diagram
przejścia. Pulsacje ciśnienia mogą wywołać rezonans strukturalny związany z częstotliwościami własnymi elementów
pompy bądź rezonans akustyczny w elementach rurowych. Znajomość częstotliwości łopatkowych ułatwia diagnostykę
drgań pompy wirowej. Pulsacje ciśnienia można zmniejszyć bądź przez stoczenie wirnika bądź skośny kształt
krawędzi łopatek wirnika lub kierownicy.

Ammonia has received significant attention as a fuel due to its carbon-free molecular structure. However, burning ammonia is challenging because of its low laminar burning velocity. To promote the combustion velocity, the authors propose a constant volume combustion chamber with a sub-chamber. This study investigated the effects of the mixing time and equivalence ratio of the ammonia/oxygen/argon mixture on combustion. The mean velocity of the ejection from the sub-chamber can be calculated by evaluating the combustion pressure, mass fraction burned, and volume fraction burned. It was clarified that with the sub-chamber structure, the ejection from the sub-chamber improved the compression and turbulence of unburned gas in the main chamber and increased the mean flame velocity of ammonia combustion. The appropriate glow plug temperature could improve the ignitability of the fuel mixture, leading to increased combustion efficiency, maximum combustion pressure, and reduced combustion time.