Diseño de los sistemas de comunicación en plantas de exploración y producción de hidrocarburos

Las plantas industriales de exploración y producción de petróleo y gas disponen de numerosos sistemas de comunicación que permiten el correcto funcionamiento de los procesos que tienen lugar en ella así como la seguridad de la propia planta. Para el presente Proyecto Fin de Carrera se ha llevado a cabo el diseño del sistema de megafonía PAGA (Public Address and General Alarm) y del circuito cerrado de televisión (CCTV) en la unidad de procesos Hydrocrcaker encargada del craqueo de hidrógeno. Partiendo de los requisitos definidos por las especificaciones corporativas de los grupos petroleros para ambos sistemas, PAGA y CCTV, se han expuesto los principios teóricos sobre los que se fundamenta cada uno de ellos y las pautas a seguir para el diseño y demostración del buen funcionamiento a partir de software específico. Se ha empleado las siguientes herramientas software: EASE para la simulación acústica, PSpice para la simulación eléctrica de las etapas de amplificación en la megafonía; y JVSG para el diseño de CCTV. La sonorización tanto de las unidades como del resto de instalaciones interiores ha de garantizar la inteligibilidad de los mensajes transmitidos. La realización de una simulación acústica permite conocer cómo va a ser el comportamiento de la megafonía sin necesidad de instalar el sistema, lo cual es muy útil para este tipo de proyectos cuya ingeniería se realiza previamente a la construcción de la planta. Además se comprueba el correcto diseño de las etapas de amplificación basadas en líneas de alta impedancia o de tensión constante (100 V). El circuito cerrado de televisión (CCTV) garantiza la transmisión de señales visuales de todos los accesos a las instalaciones y unidades de la planta así como la visión en tiempo real del correcto funcionamiento de los procesos químicos llevados a cabo en la refinería. El sistema dispone de puestos de control remoto para el manejo y gestión de las cámaras desplegadas; y de un sistema de almacenamiento de las grabaciones en discos duros (RAID-5) a través de una red SAN (Storage Area Network). Se especifican las diferentes fases de un proyecto de ingeniería en el sector de E&P de hidrocarburos entre las que se destaca: propuesta y adquisición, reunión de arranque (KOM, Kick Off Meeting), estudio in situ (Site Survey), plan de proyecto, diseño y documentación, procedimientos de pruebas, instalación, puesta en marcha y aceptaciones del sistema. Se opta por utilizar terminología inglesa dado al ámbito global del sector. En la última parte del proyecto se presenta un presupuesto aproximado de los materiales empleados en el diseño de PAGA y CCTV. ABSTRACT. Integrated communications for Oil and Gas allows reducing risks, improving productivity, reducing costs, and countering threats to safety and security. Both PAGA system (Public Address and General Alarm) and Closed Circuit Television have been designed for this project in order to ensure a reliable security of an oil refinery. Based on the requirements defined by corporate specifications for both systems (PAGA and CCTV), theoretical principles have been presented as well as the guidelines for the design and demonstration of a reliable design. The following software has been used: EASE for acoustic simulation; PSpice for simulation of the megaphony amplification loops; and JVSG tool for CCTV design. Acoustic for both the units and the other indoor facilities must ensure intelligibility of the transmitted messages. An acoustic simulation allows us to know how will be the performance of the PAGA system without installing loudspeakers, which is very useful for this type of project whose engineering is performed prior to the construction of the plant. Furthermore, it has been verified the correct design of the amplifier stages based on high impedance lines or constant voltage (100 V). Closed circuit television (CCTV) ensures the transmission of visual signals of all access to facilities as well as real-time view of the proper functioning of chemical processes carried out at the refinery. The system has remote control stations for the handling and management of deployed cameras. It is also included a storage system of the recordings on hard drives (RAID - 5) through a SAN (Storage Area Network). Phases of an engineering project in Oil and Gas are defined in the current project. It includes: proposal and acquisition, kick-off meeting (KOM), Site Survey, project plan, design and documentation, testing procedures (SAT and FAT), installation, commissioning and acceptance of the systems. Finally, it has been presented an estimate budget of the materials used in the design of PAGA and CCTV.

Bit noise from an optical logic gate with laser diodes

Output bits from an optical logic cell present noise due to the type of technique used to obtain the Boolean functions of two input data bits. We have simulated the behavior of an optically programmable logic cell working with Fabry Perot-laser diodes of the same type employed in optical communications (1550nm) but working here as amplifiers. We will report in this paper a study of the bit noise generated from the optical non-linearity process allowing the Boolean function operation of two optical input data signals. Two types of optical logic cells will be analyzed. Firstly, a classical "on-off" behavior, with transmission operation of LD amplifier and, secondly, a more complicated configuration with two LD amplifiers, one working on transmission and the other one in reflection mode. This last configuration has nonlinear behavior emulating SEED-like properties. In both cases, depending on the value of a "1" input data signals to be processed, a different logic function can be obtained. Also a CW signal, known as control signal, may be apply to fix the type of logic function. The signal to noise ratio will be analyzed for different parameters, as wavelength signals and the hysteresis cycles regions associated to the device, in relation with the signals power level applied. With this study we will try to obtain a better understanding of the possible effects present on an optical logic gate with Laser Diodes.

Optical regeneration based on noise generated in bistable devices: going from 2R to 3R

In this paper we propose to employ an instability that occurs in bistable devices as a control signal at the reception stage to generate the clock signal. One of the adopted configurations is composed of two semiconductor optical amplifiers arranged in a cascaded structure. This configuration has an output equivalent to that obtained from Self-Electrooptic Effect Devices (SEEDs), and it can implement the main Boolean functions of two binary inputs. These outputs, obtained from the addition of two binary signals, show a short spike in the transition from "1" to "2" in the internal processing. A similar result is obtained for a simple semiconductor amplifier with bistable behavior. The paper will show how these structures may help recover clock signals in any optical transmission system

Experimental measurements of the scattered-light polarization from different liquid flows

An experimental system designed to measure very low optical powers, of the order of a few picowatts, is presented. Its main aid is to detect the polarisation state of scattered light from a fluid flow, in different angular directions with respect to the longitudinal axis of the flow. A laser beam incident linearly polarized crosses the fluid flow orthogonally. The scattered light is detected by means of a photodetector situated behind a lineal polarizer whose orientation can be rotated. The outgoing electrical signal is amplified by means of a Mode-lockin amplifier and is digitally processed.

Wavelength monitoring with semiconductor laser amplifiers

The semiconductor laser diodes that are typically used in applications of optical communications, when working as amplifiers, present under certain conditions optical bistability, which is characterized by abruptly switching between two different output states and an associated hysteresis cycle. This bistable behavior is strongly dependent on the frequency detuning between the frequency of the external optical signal that is injected into the semiconductor laser amplifier and its own emission frequency. This means that small changes in the wavelength of an optical signal applied to a laser amplifier causes relevant changes in the characteristics of its transfer function in terms of the power requirements to achieve bistability and the width of the hysteresis. This strong dependence in the working characteristics of semiconductor laser amplifiers on frequency detuning suggest the use of this kind of devices in optical sensing applications for optical communications, such as the detection of shifts in the emission wavelength of a laser, or detect possible interference between adjacent channels in DWDM (Dense Wavelength Division Multiplexing) optical communication networks

Vertical-cavity semiconductor optical amplifiers (VCSOAs) as optical sensing elements

Semiconductor Optical Amplifiers (SOAs) have mainly found application in optical telecommunication networks for optical signal regeneration, wavelength switching or wavelength conversion. The objective of this paper is to report the use of semiconductor optical amplifiers for optical sensing taking into account their optical bistable properties. As it was previously reported, some semiconductor optical amplifiers, including Fabry-Perot and Distributed-Feedback Semiconductor Optical Amplifiers (FPSOAs and DFBSOAs), may exhibit optical bistability. The characteristics of the attained optical bistability in this kind of devices are strongly dependent on different parameters including wavelength, temperature or applied bias current and small variations lead to a change on their bistable properties. As in previous analyses for Fabry-Perot and DFB SOAs, the variations of these parameters and their possible application for optical sensing are reported in this paper for the case of the Vertical-Cavity Semiconductor Optical Amplifier (VCSOA). When using a VCSOA, the input power needed for the appearance of optical bistability is one order of magnitude lower than that needed in edge-emitting devices. This feature, added to the low manufacturing costs of VCSOAs and the ease to integrate them in 2-D arrays, makes the VCSOA a very promising device for its potential use in optical sensing applications.

High data rate modulation of high power 1060-nm DBR tapered lasers with separate contacts

Direct optical modulation at 2.5 Gb/s with amplitude of more than 0.5 W has been demonstrated in single longitudinal mode distributed Bragg reflector tapered lasers emitting at 1060 nm with separated injection of the ridge waveguide and tapered sections. The modulating signal of ~110 mA peak to peak was applied to the ridge waveguide section, yielding a high modulation efficiency of ~5 W/A. The large-signal frequency response of the experimental set-up was limited by the bandwidth of the electrical amplifier rather than by the internal dynamics of the laser, indicating that higher bit rates could be achieved with improved driving electronics.

Robust control of underactuated wheeled mobile manipulators using GPI disturbance observers

This article describes the design of a linear observer–linear controller-based robust output feedback scheme for output reference trajectory tracking tasks in the case of nonlinear, multivariable, nonholonomic underactuated mobile manipulators. The proposed linear feedback scheme is based on the use of a classical linear feedback controller and suitably extended, high-gain, linear Generalized Proportional Integral (GPI) observers, thus aiding the linear feedback controllers to provide an accurate simultaneous estimation of each flat output associated phase variables and of the exogenous and perturbation inputs. This information is used in the proposed feedback controller in (a) approximate, yet close, cancelations, as lumped unstructured time-varying terms, of the influence of the highly coupled nonlinearities, and (b) the devising of proper linear output feedback control laws based on the approximate estimates of the string of phase variables associated with the flat outputs simultaneously provided by the disturbance observers. Simulations reveal the effectiveness of the proposed approach.

Building lean thinking in a telecom software development organization: strengths and challenges.

The potential shown by Lean in different domains has aroused interest in the software industry. However, it remains unclear how Lean can be effectively applied in a domain such as software development that is fundamentally different from manufacturing. This study explores how Lean principles are implemented in software development companies and the challenges that arise when applying Lean Software Development. For that, a case study was conducted at Ericsson R&D Finland, which successfully adopted Scrum in 2009 and subsequently started a comprehensible transition to Lean in 2010. Focus groups were conducted with company representatives to help devise a questionnaire supporting the creation of a Lean mindset in the company (Team Amplifier). Afterwards, the questionnaire was used in 16 teams based in Finland, Hungary and China to evaluate the status of the transformation. By using Lean thinking, Ericsson R&D Finland has made important improvements to the quality of its products, customer satisfaction and transparency within the organization. Moreover, build times have been reduced over ten times and the number of commits per day has increased roughly five times.The study makes two main contributions to research. First, the main factors that have enabled Ericsson R&D?s achievements are analysed. Elements such as ?network of product owners?, ?continuous integration?, ?work in progress limits? and ?communities of practice? have been identified as being of fundamental importance. Second, three categories of challenges in using Lean Software Development were identified: ?achieving flow?, ?transparency? and ?creating a learning culture?

Dynamical characterization of monolithic MOPAs emitting at 1.5 μ�m

Eye-safety requirements in important applications like LIDAR or Free Space Optical Communications make specifically interesting the generation of high power, short optical pulses at 1.5 um. Moreover, high repetition rates allow reducing the error and/or the measurement time in applications involving pulsed time-of-flight measurements, as range finders, 3D scanners or traffic velocity controls. The Master Oscillator Power Amplifier (MOPA) architecture is an interesting source for these applications since large changes in output power can be obtained at GHz rates with a relatively small modulation of the current in the Master Oscillator (MO). We have recently demonstrated short optical pulses (100 ps) with high peak power (2.7 W) by gain switching the MO of a monolithically integrated 1.5 um MOPA. Although in an integrated MOPA the laser and the amplifier are ideally independent devices, compound cavity effects due to the residual reflectance at the different interfaces are often observed, leading to modal instabilities such as self-pulsations.

Modelización de la zona de inundación del río Forcón-Barranca a su paso por San Miguel de Reinante

El presente proyecto muestra el estudio realizado para evaluar la capacidad de drenaje de la canalización construida en el río Forcón-Barranca, en la población de San Miguel de Reinante (Lugo), a consecuencia de las severas inundaciones acaecidas los días 9 y 10 de junio de 2010. Para evaluar y analizar la peligrosidad se ha seguido un método hidrometeorológico agregado, debido a la falta de aforos, pluviómetros y datos, y se han usado Modelos Digitales de Elevaciones como punto de partida. Todo ello ha llevado a la conclusión de la ineficacia del canal para un período de retorno de 500 años. ABSTRACT After severe flooding in San Miguel de Reinante (Lugo) the 9th and 10th June 2010, a concrete channel was built. This project assesses the drainage capacity of such channel, performing a flood hazard analysis. Because no flow measures or rain gauge data were available a lumped model was followed in order to evaluate flood hazard, using Digital Elevation Models as a starting point. This has led to the conclusion that the channel cannot effectively drain a flow after a rainfall with a return period of 500 years.

Exact solution for the conjugate fluid-fluid problem in the thermal entrance region of laminar counterflow heat exchangers

A generalized Lévêque solution is presented for the conjugate fluid–fluid problem that arises in the thermal entrance region of laminar counterflow heat exchangers. The analysis, carried out for constant property fluids, assumes that the Prandtl and Peclet numbers are both large compared to unity, and neglects axial conduction both in the fluids and in the plate, assumed to be thermally thin. Under these conditions, the thermal entrance region admits an asymptotic self-similar description where the temperature varies as a power ϳ of the axial distance, with the particularity that the self-similarity exponent must be determined as an eigenvalue by solving a transcendental equation arising from the requirement of continuity of heat fluxes at the heat conducting wall. Specifically, the analysis reveals that j depends only on the lumped parameter ƙ = (A2/A1)1/3 (α1/α2)1/3(k2/k1), defined in terms of the ratios of the wall velocity gradients, A, thermal diffusivities, α i, and thermal conductivities,k i, of the fluids entering, 1, and exiting, 2, the heat exchanger. Moreover, it is shown that for large (small) values of K solution reduces to the classical first (second) Lévêque solution. Closed-form analytical expressions for the asymptotic temperature distributions and local heat-transfer rate in the thermal entrance region are given and compared with numerical results in the counterflow parallel-plate configuration, showing very good agreement in all cases.

Divisores Wilkinson con elementos concentrados para procesado de pulsos

Some photodetectors like PMTs and SiPMs give pulses of few nanosecond width at their outputs, which need to be properly processed with analog circuits. Power splitters with two and three outputs are required to distribute this kind of fast pulses equally among different outputs. Good matching and low pass response are necessary to avoid shape deformation, which discard low frequency designs with operational amplifiers. To match these requirements two Wilkinson dividers were designed, substituting the lambda quarter lines for lumped elements. These changes provide us with low pass response and much smaller size, using SMD devices. The splitters were manufactured and measured, with good results.

Simulación, construcción y medida de un sistema de telealimentación eficiente

Los sistemas de telealimentación han tomado gran importancia en diferentes campos, incluido el de las telecomunicaciones, algunos ejemplos pueden ser: En la red conmutada telefónica junto con la señal de información y llamada existe una alimentación de 48v que se transmite a través de toda la línea de transmisión hasta los terminales. En algunos ferrocarriles eléctricos, se aprovecha la producción de energía eléctrica cuando un tren baja una cuesta y el motor funciona como generador, devolviendo la energía excedente a la propia catenaria por medio de superposición, y siendo esta recuperada en otro lugar y aprovechada por ejemplo por otro tren que requiere energía. Otro uso en ferrocarriles de la telealimentación es la llamada "tecnología del transpondedor magnético", en la que el tren transmite a las balizas una señal en 27MHz además de otras de información propias, que se convierte en energía útil para estas balizas. En este proyecto pretendemos implementar un pequeño ejemplo de sistema de telealimentación trabajando en 5 MHz (RF). Este sistema transforma una señal de CC en una señal de potencia de CA que podría ser, por ejemplo, transmitida a lo largo de una línea de transmisión o radiada por medio de una antena. Después, en el extremo receptor, esta señal RF se transforma finalmente en DC. El objetivo es lograr el mejor rendimiento de conversión de energía, DC a AC y AC a DC. El sistema se divide en dos partes: El inversor, que es la cadena de conversión DC-AC y el rectificador, que es la cadena de conversión AC-DC. Cada parte va a ser calculada, simulada, implementada físicamente y medida aparte. Finalmente el sistema de telealimentación completo se va a medir mediante la interconexión de cada parte por medio de un adaptador o una línea de transmisión. Por último, se mostrarán los resultados obtenidos. ABSTRACT. Remote powering systems have become very important in different fields, including telecommunications, some examples include: In the switched telephone network with the information signal and call there is a 48v supply that is transmitted across the transmission line to the terminals. In some electric railways, the production of electrical energy is used when a train is coming down a hill and the motor acts as a generator, returning the surplus energy to the catenary itself by overlapping, and this being recovered elsewhere and used by other train. Home TV amplifiers that are located in places (storage, remote locations ..) where there is no outlet, remote power allows to carry information and power signal by the same physical medium, for instance a coax. The AC power signal is transformed into DC at the end to feed the amplifier. In medicine, photovoltaic converters and fiber optics can be used as means for feeding devices implanted in patients. Another use of the remote powering systems on railways is the "magnetic transponder technology", in which the station transmits a beacon signal at 27MHz own as well as other information, which is converted into useful energy to these beacons. In this Project we are pretending to implement a little example of remote powering system working in 5 MHz (RF). This system transform DC into an AC-RF power signal which could be, for instance, transmitted throughout a transmission line or radiated by means of an aerial. At the receiving end, this RF signal is then transformed to DC. The objective is to achieve the best power conversion performance, DC to AC and AC to DC. The system is divided in two parts: The inverter, that is the DC-AC conversion chain and the rectifier that is the AC-DC conversion chain. Each part is going to be calculated, simulated, implemented physically and measured apart. Then the complete remote-powering system is to be measured by interconnecting each part by means of a interconnector or a transmission line. Finally, obtained results will be shown.

Análisis y diseño de multiplicadores y mezcladores mediante el método de Monte Carlo en la banda de THz = Analysis and design of multipliers and mixers via Monte Carlo modelling at THz bands

La región del espectro electromagnético comprendida entre 100 GHz y 10 THz alberga una gran variedad de aplicaciones en campos tan dispares como la radioastronomía, espectroscopíamolecular, medicina, seguridad, radar, etc. Los principales inconvenientes en el desarrollo de estas aplicaciones son los altos costes de producción de los sistemas trabajando a estas frecuencias, su costoso mantenimiento, gran volumen y baja fiabilidad. Entre las diferentes tecnologías a frecuencias de THz, la tecnología de los diodos Schottky juega un importante papel debido a su madurez y a la sencillez de estos dispositivos. Además, los diodos Schottky pueden operar tanto a temperatura ambiente como a temperaturas criogénicas, con altas eficiencias cuando se usan como multiplicadores y con moderadas temperaturas de ruido en mezcladores. El principal objetivo de esta tesis doctoral es analizar los fenómenos físicos responsables de las características eléctricas y del ruido en los diodos Schottky, así como analizar y diseñar circuitos multiplicadores y mezcladores en bandas milimétricas y submilimétricas. La primera parte de la tesis presenta un análisis de los fenómenos físicos que limitan el comportamiento de los diodos Schottky de GaAs y GaN y de las características del espectro de ruido de estos dispositivos. Para llevar a cabo este análisis, un modelo del diodo basado en la técnica de Monte Carlo se ha considerado como referencia debido a la elevada precisión y fiabilidad de este modelo. Además, el modelo de Monte Carlo permite calcular directamente el espectro de ruido de los diodos sin necesidad de utilizar ningún modelo analítico o empírico. Se han analizado fenómenos físicos como saturación de la velocidad, inercia de los portadores, dependencia de la movilidad electrónica con la longitud de la epicapa, resonancias del plasma y efectos no locales y no estacionarios. También se ha presentado un completo análisis del espectro de ruido para diodos Schottky de GaAs y GaN operando tanto en condiciones estáticas como variables con el tiempo. Los resultados obtenidos en esta parte de la tesis contribuyen a mejorar la comprensión de la respuesta eléctrica y del ruido de los diodos Schottky en condiciones de altas frecuencias y/o altos campos eléctricos. También, estos resultados han ayudado a determinar las limitaciones de modelos numéricos y analíticos usados en el análisis de la respuesta eléctrica y del ruido electrónico en los diodos Schottky. La segunda parte de la tesis está dedicada al análisis de multiplicadores y mezcladores mediante una herramienta de simulación de circuitos basada en la técnica de balance armónico. Diferentes modelos basados en circuitos equivalentes del dispositivo, en las ecuaciones de arrastre-difusión y en la técnica de Monte Carlo se han considerado en este análisis. El modelo de Monte Carlo acoplado a la técnica de balance armónico se ha usado como referencia para evaluar las limitaciones y el rango de validez de modelos basados en circuitos equivalentes y en las ecuaciones de arrastredifusión para el diseño de circuitos multiplicadores y mezcladores. Una notable característica de esta herramienta de simulación es que permite diseñar circuitos Schottky teniendo en cuenta tanto la respuesta eléctrica como el ruido generado en los dispositivos. Los resultados de las simulaciones presentados en esta parte de la tesis, tanto paramultiplicadores comomezcladores, se han comparado con resultados experimentales publicados en la literatura. El simulador que integra el modelo de Monte Carlo con la técnica de balance armónico permite analizar y diseñar circuitos a frecuencias superiores a 1 THz. ABSTRACT The terahertz region of the electromagnetic spectrum(100 GHz-10 THz) presents a wide range of applications such as radio-astronomy, molecular spectroscopy, medicine, security and radar, among others. The main obstacles for the development of these applications are the high production cost of the systems working at these frequencies, highmaintenance, high volume and low reliability. Among the different THz technologies, Schottky technology plays an important rule due to its maturity and the inherent simplicity of these devices. Besides, Schottky diodes can operate at both room and cryogenic temperatures, with high efficiency in multipliers and moderate noise temperature in mixers. This PhD. thesis is mainly concerned with the analysis of the physical processes responsible for the characteristics of the electrical response and noise of Schottky diodes, as well as the analysis and design of frequency multipliers and mixers at millimeter and submillimeter wavelengths. The first part of the thesis deals with the analysis of the physical phenomena limiting the electrical performance of GaAs and GaN Schottky diodes and their noise performance. To carry out this analysis, a Monte Carlo model of the diode has been used as a reference due to the high accuracy and reliability of this diode model at millimeter and submillimter wavelengths. Besides, the Monte Carlo model provides a direct description of the noise spectra of the devices without the necessity of any additional analytical or empirical model. Physical phenomena like velocity saturation, carrier inertia, dependence of the electron mobility on the epilayer length, plasma resonance and nonlocal effects in time and space have been analysed. Also, a complete analysis of the current noise spectra of GaAs and GaN Schottky diodes operating under static and time varying conditions is presented in this part of the thesis. The obtained results provide a better understanding of the electrical and the noise responses of Schottky diodes under high frequency and/or high electric field conditions. Also these results have helped to determine the limitations of numerical and analytical models used in the analysis of the electrical and the noise responses of these devices. The second part of the thesis is devoted to the analysis of frequency multipliers and mixers by means of an in-house circuit simulation tool based on the harmonic balance technique. Different lumped equivalent circuits, drift-diffusion and Monte Carlo models have been considered in this analysis. The Monte Carlo model coupled to the harmonic balance technique has been used as a reference to evaluate the limitations and range of validity of lumped equivalent circuit and driftdiffusion models for the design of frequency multipliers and mixers. A remarkable feature of this reference simulation tool is that it enables the design of Schottky circuits from both electrical and noise considerations. The simulation results presented in this part of the thesis for both multipliers and mixers have been compared with measured results available in the literature. In addition, the Monte Carlo simulation tool allows the analysis and design of circuits above 1 THz.