Boletín IIE julio-septiembre-2012 Artículo de ... · the 13.8 kV to 34.5 kV BS in two refine-ries from the north of Mexico, and 1 elec-trical upgrading of 13.8 kV to 115 kV in one

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Boletín IIEjulio-septiembre-2012Artículo de investigación

Abstract

Nowadays the refining sector in Mexico needs to increase the quantity and quality of produced fuels by installing new process plants for gasoline and ultra low sulphur diesel. These plants require the provision of electricity and steam, among other services to function properly, which can be supplied by the power plants currently installed in each refinery through an expansion of their generation capacity. These power plants need to increase its production of electricity and steam at levels above their installed capacity, which involves the addition of new power generating equipment (gas or steam turbo-generators) as well as the raise of the electrical loads. Currently, the Mexican Petroleum Company (PEMEX) is planning to restructure their electrical and steam systems in order to optimally supply the required services for the production of high quality fuels. In this paper the present status of the original electrical power systems of the refineries is assessed and the electrical integration of new process plants in the typical schemes is analyzed. Also this paper shows the conceptual schemes proposed to restructure the electrical power system for two refineries and the strategic planning focused on implement the modifications required for the integration of new process plants that will demand about 20 MW for each refinery by 2014. The results of the analysis allowed to identify the current conditions of the electrical power systems in the oil refining industry or National Refining Industry (NRI), and thereby to offer technical solutions that could be useful to engineers facing similar projects.

Keywords: clean fuel, combined efficiency, conceptual design, economic assessment, electrical net, electrical system, electrical trans-former, interrupt capacity, load flow, refinery power plant, refining, short circuit, synchronization bus, three wind.

Assessment and planning of the electrical systems in Mexican refineries by 2014

Luis Iván Ruiz Flores1, José Hugo Rodríguez Martínez1, Guillermo Darío Taboada2 y Javier Pano Jiménez2

1 Instituto de Investigaciones Eléctricas (IIE)2 Petróleos Mexicanos (PEMEX)

Paper originally presented at the ASME Power Conference in Denver, Colorado, July 12-14, 2011.

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Artículo de investigaciónAssessment and planning of the electrical

systems in Mexican refineries by 2014

Resumen

Hoy en día, el sector de refinación en México necesita aumentar la cantidad y calidad de los combustibles producidos, mediante la instalación de nuevas plantas de proceso para la gasolina y el diésel ultra bajo en azufre. Estas plantas requieren el suministro de electricidad y vapor de agua, entre otros servicios, para que funcione correctamente, los cuales pueden ser sumi-nistrados por las fuentes de generación instaladas en cada una de las refinerías y a través de una expansión de su capacidad de generación. Estas centrales eléctricas necesitan aumentar su producción de electricidad y vapor de agua a niveles por encima de su capacidad instalada, lo que significa integrar nuevos equipos de gene-ración de energía (gas o vapor turbogene-radores), así como el aumento de las cargas eléctricas. En la actualidad, Petróleos Mexi-canos (PEMEX) tiene la intención de rees-tructurar sus sistemas eléctricos y de vapor, a fin de suministrar de forma óptima los servicios requeridos para la producción de combustibles de alta calidad. En este artí-culo se presenta la situación actual de los sistemas de energía eléctricas originales de las refinerías y se evalúa la integración eléc-trica de las plantas de proceso en los nuevos esquemas típicos. También se presentan los esquemas conceptuales propuestos para reestructurar el sistema de energía eléc-trica para dos refinerías, cuya planificación estratégica se centró en la aplicación de las modificaciones necesarias para la inte-gración de nuevas plantas de proceso que demandarán alrededor de 20 MW para cada refinería en el año 2014. Los resultados del análisis permitieron identificar las condi-ciones actuales de los sistemas de energía eléctrica en la industria de refinación de petróleo o de la Industria Nacional de Refi-

nación (INR), y por lo tanto ofrecer solu-ciones técnicas que podrían ser útiles para los ingenieros que desarrollan proyectos similares.

Introduction

Currently, the oil refining industry is in upgrading process of its electric system in order to supply the oil demand. Every oil refinery are linked up to The National Electrical System (NES) to ensure the electrical energy continuity in eventua-lity situations; however, the acquisition energy cost and the fees payment is up to USD $ 800 000 per month.

In the other hand, because of the new requirements NRI has presented new action schemes, like migrate from 13.8 kV to 35.5 kV, and to 115 kV in some cases (García et al, 2008). Moreover, there are operative limitations which generate non programmed shutdowns, for example: between 2005 and 2006 there were three non programmed stops because of “the generation sources floating neutral” (García et al, 2008; (García et al, 2005).

Additionally NRI tends to process different crude oil from the ones that produced more than 30 years ago, that means that electrical systems must evolve. NRI has taken in account an investment for electrical reconstructing for more than USD $ 120 million only for one refinery.

For that reason, and to support the actual and future electric demands, it is necessary to use supply steam, compressed air, water and electric energy in the next decades.

The purpose of that document is to give the experience, obtained through an

equipment integration analysis, and new electric generators which permit it to be self-sufficient to reach an electrical power of 120 MW with a 34.5 kV level and 320 MW with a 115 kV level as means of distribution. The results presented here can be useful to solve problems in similar projects.

Background

Current Schemes

Instituto de Investigaciones Eléctricas (IIE), Mexican public decentralized orga-nism created for technological researches, has been working with NRI since 2002 about a) development of conceptual engi-neering for electrical systems, b) tech-nical-financial feasibility study, c) electrical equipment specifications, d) user bases, e) tender bases, f) the analysis of power electrical systems to implement specific solutions for the electrical, mechanical and control equipments.

NRI consists of six refineries in Mexico: Cadereyta, Nuevo León (HRLS); Cd. Madero, Tamaulipas (FIM); Tula, Hidalgo (MHI); Salamanca, Guanajuato (AMA); Minatitlán, Veracruz (LC) y Salina Cruz, Oaxaca (ADJ). In the table 1, it is shown the results of the work between IIE and NRI which generate the necessity of the construction of 4 electric genera-tors with heat recovery, 1 steam boiler, 2 electrical upgrading with the migration of the 13.8 kV to 34.5 kV BS in two refine-ries from the north of Mexico, and 1 elec-trical upgrading of 13.8 kV to 115 kV in one refinery from the center of Mexico.

The modernization of every SEP was regarded because of the convenience of Pa

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the implementation of 2 alternatives for the new generation unities: a) with a gas generator and b) with a steam generator. The table 2 shows the comparison of the alternatives to take the decision to integrate a gas generator into the new schemes.

Taken decisions for upgradings systems

Many specialists take part into the elec-trical upgrading asset, somebody have been developed the conceptual enginee-ring and others decide whether every project has economical feasibility for its development. For example, NRI has different sections which take part into the project decisions like: a) Investment Analysis Department (GAIGO: Gerencia de Análisis de Inversión), b) Projects Development Engineering Department (DCIPD: Dirección Corporativa de Ingeniería y Desarrollo de Proyectos), c) Operations Department (DCO: Direc-ción Corporativa de Operaciones), d) Proscess Engineering Department (GIP: Gerencia de Ingeniería de Procesos) and e) The local users of every refinery.

The intervention of NRI entities let the management and development of projects which needs a future: a) supply of the same actual demand of energy, b) the integration of the new generation modules; c) high resistance grounding neutral method; d) the ideal energy flow; e) the charges redistribu-tion and f) the energy supply of the Clean Fuel Projects Quality (CFPQ) mentioned in (García et al, 2009; Alcaraz et al, 2008). In the figure 1 it is shown the IIE partici-pation and the awaited electric upgrading projection for the 2012.

ConceptRefineries

HRLS FIM MHI AMA LC ADJConceptual engineering þ þ þ þ þ þ

Generator tender þ þ þ þ

PCC Loads tender þ þ þ þ þ þ

Gruunding c/ High impedance þ þ þ

Technical-economic feasibility þ þ þ þ þ þ

Electric upgrading þ þ þ

Technical consultant tender þ

Steam boiler tender þ

TURBOGENERATOR STEAM TURBOGENERATOR TO GASThis alternative needs:(180 t/h) additional steam generator to ensure existent production and rehabilitation

Heat retriever to seize gases combustión and steam generator of 19 bar

TG1 and TG2 existing electric generators rehabilitation

TG1 and TG2 existing steam and electric generator rehabilitation

To wide the cooling system in case of partial condensation work. That means an increase water consumption in the refinery

To analyze the gas availability and to ponder prices volatility

The actual electric system improvement The actual electric system improvementAcquiring the turbogenerator and their peripherial Acquiring the turbogenerator and their peripherial

Advantages:Use oil or/and gas as fuel in boilers There is a decrease in the consumption of oil in the

refinery (It is saved medium pressure in boilers)This schemes are well known in the refineries Use diesel and/or gas as fuel in gas turbines

There is a permanence of actual waterThere is an improvement in global efficiency of the refinery

Disadvantages:There is no improvement in global efficiency of the refinery

It is necessary to consider that there is a major main-tenance if diesel is burned, moreover the heat retriever will need soot blower

Stop the refinery process to make the new turbo generator connection The users refinery do not know well those schemes

Table 1. Results of IIE and NRI together working by now.

Table 2. Comparison between gas generator steam generator.

Conceptual engineering of actual and typical future electrical system

NRI actual typical electric systems

The electrical actual net of the six refineries in Mexico, have limitations in 13.8 kV distri-bution interruptive capacity switchgear. The actual average capacity of those switchgear is 31.5 kA short circuit in case of three-phase failure (Icc 3F). 31.5 kA means 100% of the capacity which support the equipments according to manufactures production line; however it is considered to maintain a 20% security margin for future expansion in that level.Pa

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The generators neutral was connected to a common point named “neutral bus or neutral switchgear” through an interrupter and grounded through a low resistence bank. Only the link transformer neutral with the public net and a generator neutral are grounding, the rest of the generators work “ungrounded”.

They have a redundant system to supply energy with at least two generation sources trough the 13.8 kV distribution buses or the existent 14.6 kV link interrupters called

“selective secondary”. In case of contingence, if a switchgear gets out of maintenance, the charges can be transferred to their adja-cent switchgear or through the synchro-nization bus to obtain the an energy flow that supplies electric energy in two inclusive subsystems.

Electrical system with three generation sources

Figures 2, 3 and 4 shows the actual scheme of a refinery which has two power plants,

that supply the electric energy (92 MW) and the steam that needs their process plants with two generators. The power plant No. 1 has a 18 MW (TE-1) “turbo expander” installed in the catalytic plant and two 32 MW steam turbo generator (TG1 and TG-2) and four boilers that generate 60 kg/cm2 man steam and a boiler that generates 20 kg/cm2 man steam. The gene-rators TG-1 and TG-2 work with extrac-tion, giving 20 kg/cm2 man steam. The power plant No. 2 has two boilers which gives 20 kg/cm2 man steam (B-001A and B-001B) and two boilers that gives 3.520 kg/cm2 man (B-002A and B-002B). Addi-tionally, the refinery has three energy flows, two of 230 kV and one of 115 kV that come fron NES. Every flow of 230 kV has a 84 MVA maximum capacity and the one of 115 kV has a capacity of of 20 MVA. The 115 flow is connected to the TDP-3 TDP-3 and currently is out of service because is used as backup in one of the 230 kV energy flow, that way there is a deficit energy supply in the refinery through link substations. Finally, all the 13.8 kV distribu-tion switchgears has an interruptive capa-city and the 31.5 kA design for the symme-trical three phase short circuit flow.

In actual conditions, the power plant does not supply the total electric energy neces-sity in the 92 MW refinery, therefore is necessary the exchange of 40 MW from other sources of NRI or NES.

Electrical system with more than 4 generation sources

Figure 5 shows the actual scheme of a refinery with more than for electric gene-rators divided into two thermoelectric plants which supplies a charge average of 97 MW. The plant 1 has 6 boilers called

Figure 1. Work together between IIE and NRI for the execution of upgradings projects.

Figure 2. Representative scheme of a refinery which has two generation sources synchronized with NES.

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In actual conditions, the energy plant does not cover the total electrical energy neces-sity of the 97 MW refineries it is necessary 14 MW energy exchange from other NRI or NES work center.

These descriptions indicate a conceptual design must have a rational procedure to determinate the best plan generated by at least three conceptual scheme models. In other articles published by these authors, they present recommendations which have been usual to modify schemes showed in figures 2 and 4 (Ruiz et al, 2009).

To describe the alternatives chosen for NRI electrical upgrading there will be presented the factors that suffer changes because of project made by IIE and the benefits that will receive in 2012.

Future electrical system for NRI

The generation capacity of the majority of the six refineries, is practically the same as charge demand (100 MW). There is no warranty in the continuous energy supply, not even for the actual process plant in case of emergency, not even for the new plants. For that reason, it was regarded to reconstructing the tension to 34.5 kV level in two refineries. In this clause there will be included the electrical schemes which will be established for the figures showed in figures 2 and 4.

Every scheme showed, for the 3-generator refinery and for 4-generator refinery, was analyzed through stable state evaluation of the electrical system performance with three phase short circuits, charges flow, tension falls, power factor and tension regulation (Ruiz et al, 2009).

MP-B1, MP-B2, MP-B3, MP-B4, CB2 y TG-4, and 4 turbo generators called TG-1, TG-2, TG-3 and TG-4.

The turbo generators TG-1, TG-2 and TG-3 are designed to work at full condensation, while TG-4 turbo generator is designed to work with steam extraction and condensa-tion. The switchgear from Plant 1 has 31.5 kA interruptive capacity. The plant 2 has 3 boilers named CB-5, CB-6 and 2 turbo generator named TG-5 and TG-6. The turbo generators TG-5 and TG-6 work with steam extraction. The 2 plant switchgear has 41 kA interruptive capacity.Pa

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Figure 3. Typical actual (representative) scheme of a steam generation refinery with two electrical generators synchronized with NES.

Figure 4. Typical actual (representative) scheme of a steam generation refinery with two electrical generators synchronized with NES.

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The schemes to be established of the refineries to migrate at a 34.5 kV distribu-tion level will have supply and installation phases. The supply, installation, integra-tion, field proves, training and putting into service are divided as the following:

• Integration of an electrical generator among 31 - 38 MW capacity for refine-ries of three generators and 20 - 25 MW for refineries of more than four genera-tors to supply the actual energy supply.

• Upgrading of 13.8 to 34.5 kV bus synchronization for both refineries.

• Integration of an electrical generator among 31 - 38 MW capacity for refine-ries of three generators and 20 -25 MW for refineries of more than four genera-tors to supply the future CFPQ demand.

• Electrical distribution in switchgear for CFPQ.

• High resistance grounding of the three generation sources.

• Integration of new systems into the Advanced Operational Control System (SCOA: Sistema de Control Opera-cional Avanzado).

Table 3 shows a tentative programming but no limiting of the electric upgra-ding projects execution in refineries. The programming will depend on availability budget NRI and on fiscal year.

The main specification of the electrical equipment for the refineries electrical upgrading implementation embrace take a decision in economical investment: 1) Elec-

trical integration generators, 2) Insulated switchgear technology in SF6, 3) The power factor technology with double cooling (OA/FA) using commercial connections as “multi contact elbow bushing” and also load tab changer, 4) The decision of insta-lling grounding with zig-zag transformers, 5) The use of charge circuit for 13.8 kV and 34.5 kV with intertwine polyethylene insula-tion (XLPE) at 133% in insulation level and 6) the integration of new control systems to the SCOA systems.

In figures 6 and 7, the descriptive schemes but non limiting wich will be implemented for the refineries of three or four elec-tric generators are shown. The figures represent an integral electrical scheme for execution of the same economical exer-cise. The difference in economical inves-tment for the figure 6 scheme is more than USD $ 50 million, different from figure 7 scheme which means more than USD $120 million.

The benefits they get once those schemes are established are 1) The new scheme will permit an optimal electrical power flow to the charges, in all the operation scene-ries, without bottlenecks, 2) In contin-gence conditions, charges fall are less than +- 5% in all charge buses, 3) The backup accomplishment has the capacity to subs-titute a generator of some of the plants, in case of it is out of service, because of fall or because of maintenance, 4) Plants can receive a 18 MW additional integra-tion, 5) All the plants electrical net has only a neutral grounded for the grounding fall-protection schemes simplification. The 115 kV winding has its neutral firmly grounded. The 34.5 kV synchronization bus has a zigzag transformer. The gene-rators neutral is high resistance grounded,

Figure 5. Typical actual (representative) scheme of a steam generation refinery with more than four electrical generators synchronized with NES.

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6) If a generator is out of service, there will be capacitors banks which can supply the necessary reactive power to keep 0.9 power factor in bound accomplishment. There are many other benefits mentioned in references (García et al, 2008; Ruiz et al, 2005).

Fases TProgramming per three months

2009 2010 2011 20123 4 1 2 3 4 1 2 3 4 1 2

1 1° TG 130 = = =

2 BS Upgrading 115 = =

3 Power circuits 90 = = =

4 2º TG 112 = =

5 PCC Distribution plants 110 = = =

6 Grounding with high Z 108 = =

6 Systems integration 100 = = = = =

Notes:T Working days Z ImpedanceTG Electric generator = Three months

Table 3. Tentative programming of the future electrical system implementation phases in NRI.

Figure 6. Descriptive scheme but non limiting of SB in 34.5 kV selected for the elec-trical reconstructing of figure 2 scheme.

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Parallel solutions to the continuity projects

The actual refineries has an energy deficit and an additional 20 MW demand, that requirement could be supply with a new electrical generator integration.

The authors propose a transition stage because of the mentioned changes and because of the cases that is necessary to migrate from 13.8 kV to 34.5 kV. That stage can be implemented in case the refi-neries do not have budget availability for an integral project in one execution and at the same time of 1 and 2 phases (table 3).

The next section will present the transition alternative to connect an electrical gene-rator to the actual typical electrical system in a refinery (figure 8).

The analysis shows the integration of the first generator using two alternatives for its integration: a) through a limi-ting reactor of 0.346 ohms short circuit, 1500 A in a serial configuration with the generator and b) through a three winding transformer of 35/35/35 MVA, 13.8/14.4/34.5 kV, where the terminals of TG-“n1” generator are connected to the 13.8 kV winding, its distribution charge switchgear to the 14.4 kV winding and the 34.5 kV winding will be integrated to the future project: “34.5 kV synchronization bus implementation”.

To determin the technical and economical most feasible option to connect a new electrical generator to the electrical actual system in a typical refinery, there were regarded the two mentioned alternatives by means of a short circuit values analysis and power flow in main charge buses with

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established operation conditions exclusi-vely for the first generator.

Integration of a generation module in the actual electrical system: comparison with the use of reactor vs the use of three winding transformers

The use of three winding transformers in NRI is not yet well known, even though in other oil refined centers like “Deer Park” in Texas, USA, is used that kind of technology.

The analysis ponder the evaluation in stable state of the electrical system performance with three-phase short circuit charges, flow charges, tension falls, power factor and tension regulation. There were analyzed two scenarios including: A) All the elec-trical energy sources in 115 MW operations and b) An electrical energy source aou of service with a 115.5 MW charge.

According to results, it is showed that both alternatives are operatively reliable, however, the alternative of integrating the first TG-8 generator through a limiting reactor has major tension falls because of the impedance that affects the electricity flow. Also, that implies overworking of the generator TG-8 in case one of the genera-tors from the refinery is out of service.

On the other hand, in the alternative of integrating the generator through a three winding transformer, the tension falls are compensated by the relation between the 13.8/14.4 kV windings, it means that the tension difference of 3.04% regulates the tension in acceptable levels in the distribu-tion switchgear for the power transference in the generator in 13.8 kV or the 34.5 kV future synchronization bus.

Figure 7. Descriptive scheme but non limiting of SB in 34.5 kV selected for the elec-trical upgrading of figure 4 scheme.

Figure 8. Descriptive scheme but non limiting of a parallel alternative to connect a generator with the refineries actual scheme. Pa

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The electrical system flexibility and reliabi-lity in both alternatives are almost the same, for example, the Icc 3f has 80% of inte-rruptive capacity.

Both analyzed alternatives ensure that TG-8 integration generator will be protected by over tensions because it always will have an intentional reference of their grounding neutral and there will be used a high resis-tance grounding neutral, what will avoid great energy flows through their winding.

The alternative of using a three-phase trans-former in contingence conditions, avoids the overworking of the transformer. Moreover, with the integration of a 34.5 kV synchroni-zation bus, considered to the future implan-tation, the transformer keeps operating.

Table 4 shows the results summary of Icc 3 f and the fall tension (Ct %) with a 115.5MW charge of the alternatives analyzed through: a) a short-circuit flow limiting reactor and b) a three winding transformer.

The alternatives technical evaluation of transition stage has advantages and disad-vantages. Table 5 shows technical advan-tages and disadvantages for the alternatives to integrate the first electrical generator into a typical refinery scheme.

The two alternatives of the integration of the new electrical generation module: a) require an additional investment as “tran-sition stage” between phase 1 and phase 2 and b) shows quantities of 3F and Ct % according to the regulation (ANSI/IEEE, 1993; ANSI/IEEE, 1986).

The flexibility and reliability of the elec-trical system is improved with the use of

Figure 10. Descriptive scheme but non limiting of a “transition stage” to connect a generator to the actual refineries scheme through a three-phase transformer. (2)

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Figure 9. Descriptive scheme but non limiting of a “transition stage” to connect a generator with the actual scheme in refineries through a electric limiting reactor (I).

three winding transformer, moreover it permits the use of power equipments to be insta-lled, instead of limiting energy reactors which will get out of service.

Tables 6 and 7 show the economical evaluation of both mentioned alternatives and their associated equipments for the integration of the first generator. It is important to mention

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Parameter Load Scenary 1: Reactor 2: TransformerMaximum Icc 3 f(All TG’s)

115.5 MW

A

31.6 kA (TBSII) 29.6 kA (TBSII)

Ct % Maximum level (All TG’s)

1.87 % (TD-10)

1.86 %(TD-10)

Maximun Icc 3 f (TG-6: F.S.)

B

27.7 kA (TD-7) 25.5 kA (TBSII)

Ct % máximum level(TG-6: F.S.)

3.04 % (TD-8) * 2.92 %(TD-10)

Notes:

F.S. Out of service * New overworking generator (TG-8)

Advantages 1 2Icc 3f ≤ 25.2 kA and optimal power flow in contingence conditions þ

If the NES commitment fails, the turbo can feed 100% of the charge.If a generator fails, its charge bus is fed by TBS þ þIf BS fails, every generator remains with its charge bus þ þIf a switchgear is been repaired their charges can be transferred to an adjacent switchgear þ þ

All the generators can operate with grounding neutral. þ þCan receive a future growing of 60% Can receive a future growing of 30% Require the same investment because it maintain 13..8 kV level as distribution tension þ

Better feasibility for its implementation. þThe equipment investment will be used in future projects. þDisadvantages 1 2When a switchgear is out of service, a generator is out of service xWhen the bus A or the bus B is out of service, a flow charge NES is lost x x

If the synchronization bus fails, the NES is lost.It needs the greatest investment xIt is necessary to recharge the synchronization bus circuits which go to the TBS x x

It is not posible to recharge the distribution buses circuits which go to the TBSIf the synchronization bus fails, the refinery has to import 50 MW x x

If the synchronization bus fails, the charge of a generator is lost xIcc 3f surpass the switchgear capacity limit even though using “pyrotechnics fuses “ or “Is-limiters” x

If the two generators fail, NES can not feed 100% of the charge x xThere are no ground power references in synchronization busThe NES flows does not have charge busThe new generators does not have charge bus

Item Concept Characteristics Cost [MUSD]

1 Reactor Icc limiting charge reactor with a 2300 A, 0.346 Ω air core $ .058

2 Load circuit4 conductors per phase of XLP wire, 15 kV, class, 133%, 750 kCM caliber and an approximate length of 500 m.

$ 0.390

3 Distribution switchgear

3000 A of nominal charge switchgear with an Icc of 40 kA, 6 cells including the one of TG-8

$ 0.210

4 TG-8 Recep-tion cells

Two metal Clad cells 15 kV class, including 2000 A vacuum interruptor, measuring and protection kit.

$ 0.075

TOTAL $ 0.733

Item Concept Characteristics Cost [MUSD]

1 Three windind transformer

Three winding transformer of 35/35/35 MWA with transformation relation of 13.8/13.8/34.5 kV

$ 1.1

2 Charge circuitXLP wirw, 15 kV class, 133 %, 750 Kcm caliber for 500 m and 4 conductors per phase

$ 0.390

3 TG-8 Reception cells

Two Clad metal cells, 15 kV class including 2000 A vacuum interruptor, measuring and protection kit.

$ 0.075

4 Distribution switchgear

3000 A charge nominal switchgear inclu-ding a 40 kA Icc, 6 cells including the three winding transformer

$ 0.210

TOTAL $ 1,775

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Table 4. Comparative results table for the new generator integration.

that assenting both alternatives in economical context, the best solution is to use the limiting reactor which safes 37.8% compared to three winding transformer; however this is a short term cost. It is considered a future 34.5 kV synchronization bus reconstruc-ting, therefore the three winding transformer will be still used in

Table 5. Technical evaluation of the first generator installation using: 1) an icc energy limiting reactor or 2) a three winding transformer.

Table 6. Cost of the main equipment when TG-8 is integrated through a limiting reactor with an air core (the cost of TG-8 is not included).

Table 7. Cost of the main equipment when the tg-8 is integrated through a three winding transformer (it is not include TG-8 cost).

the reconstructing and the long term cost would be less, avoiding the investment of a transformer to synchronize in 34.5 kV the new generator in the future.

Conclusions

It is necessary to optimize and to modernize the NRI electrical systems, because it is well known that in Mexico has not been cons-tructing a new refinery since 1979 and is necessary to acquire new technology according to NOM-086 regulation for the projects of 2012 and that technology must be implanted in the mentioned refineries.

The 34.5 kV BS showed in that article for two refineries can receive new charges an new generation modules, the power flow between NES and the local system is ideal and does not needs special equip-ment for its execution, moreover it can be associated to two energy source for a charges bus.

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It is possible to implement “transition stages” through technologies like three winding transformers, every time the budget of the NRI local users do not have the total available amount for the execution of the stages in a parallel way.

There are three refineries in Mexico in upgrading process only the inves-tment of electrical equipment: a) the first in the northeast with $ 38 million dollars, b) the second in the north with $ 36 million dollars and c) the third in the center with $ 32 million dollars. Every investment should be implemented with different features, and must be included in the investment of acquisition of new generators in every refinery (cost per generator is $ 25 million dollars).

The ideal energy conditions in the country are priority of Mexico Federal Govern-ment managed by Felipe Calderón Hino-josa, who, in many meetings, has suggested the modernization of PEMEX.

The execution of the NRI projects has to supply at least 2.5 million barrels per day. The reality of the oil products in Mexico depends on the production increment and on electrical upgrading of NRI that would make PEMEX to recover the international leadership by 2014.

Nomenclature

TD Distribution switchgearTG TurbogeneratorBS Syncronization BusR ReliabilityE EfficiencyNRI National Refining IndustryCFPQ Clean Fuel Projects Quality

References

García J., Robles E., Campuzano R. Series Resonant Overvoltages due to the Neutral Grounding Scheme Used in Petrochemical Power Systems, IEEE PES T&D LATI-NAMERICA, Transmission and Distribution Confe-rence and Exposition, Bogota, Colombia, 2008.

García A., Rosales I., García J., Ruiz L. I., Robles E. Net effect in electric equipment operations, Bulletin IIE, year 29, vol. 29, num. 2, April-June 2005, page 69-74, ISSN 0185-0059, Mexico.

García J., Ruiz L. I., Fernández M. F., Alcaraz A. M. Main services to produce high quality fuel in PEMEX, Boulletin IIE, year 33, vol. 33, num. 2, April-June 2009, page. 69-74, ISSN 0185-0059, Mexico.

Alcaraz A. M., Fernández M. F., Rodriguez J. H., Ruiz L. I. Vapor balance and energy in mexican refineries simu-lator, IEEE PCIC 2008, Río de Janeiro, Brasil, 2008.

Ruiz L. I., García J., García A., Taboada G. Mexican refineries upgrading of electrical power system, IEEE

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LUIS IVÁN RUIZ FLORES[[email protected]]

Maestro en Ingeniería Industrial por la Universidad Autónoma del Estado de Morelos (UAEM) en 2004. Ingeniero Eléctrico por el Instituto Tecnológico de Orizaba en 1999. Fue becario AIT del Instituto de Investigaciones Eléctricas (IIE), en la Gerencia de Simulación de 1999 a 2000. Desde 2001 colabora como investigador en la Gerencia de Equipos Eléctricos (GEE) del Instituto, en proyectos relacionados con el análisis y diseño de sistemas eléctricos de potencia en plantas industriales. Fue el asesor del 2º lugar nacional del Certamen de Tesis en Nivel de Licenciatura en México en 2008, organizado por la ANIEI. Tiene 10 de derechos de autor en las categorías de software y obra literaria. Es miembro del IEEE y ha sido autor y coautor de artículos nacionales e internacionales.

I&CPS 2009, ISBN: 978-1-4244-3399-5, Calgary, Alberta, 2009.

Ruiz L. I., García F. A., Rosales I., García J. Electrical Engineering: Base of the analysis of electrical reconstruc-ting in Mexican typical refineries. Part I. The problem defi-nition and IR spiral, IEEE Mexico, RVP-AI Acapulco, Guerrero, Mexico, 2005.

Ruiz L. I., García F. A., Rosales I., García J. Ingeniería Eléctrica: Base of the analysis of electric reconstruction in Mexican typical refineries. Part II. The solution alternatives and conclusions”, Mexico, RVP-AI Acapulco, Guerrero, Mexico, 2005.

Std. ANSI/IEEE 141, Red Book. IEEE Recommended practice for electric power distribution for industrial plants, 1993.

Std. ANSI/IEEE 242, Buff Book. IEEE Recommended practice for protection of industrial and commercial power systems, 1986.

NOM-086-SEMARNAT-SENER-SCFI-2005. Official Mexican regulation, fossil oil specifications for environment protection, 2005.

También ha sido expositor en conferencias en foros nacionales e internacionales con diferentes institu-ciones, empresas, congresos y simposios, denotándose en las áreas eléctrica, industrial, informática y sistemas computacionales. Actualmente es investigador y jefe de laboratorio de la GEE, y contribuye con el diseño de sistemas informáticos para optimizar los procesos de licitación y modernización en la industria petrolera.

JOSÉ HUGO RODRÍGUEZ MARTÍNEZ [[email protected]]

Ingeniero Químico por el Instituto Tecnológico de Ciudad Madero. Actualmente cursa la Maestría en Ingeniería en el Centro de Investigación en Energía de la Universidad Nacional Autónoma de México (UNAM). Ha colaborado con la industria petroquímica en proyectos de optimización de procesos y mejora de productos. En 2001 ingresó a la Gerencia de Procesos Térmicos del IIE, donde ha participado y administrado proyectos relacionados con la eficiencia energética en procesos, ahorro de energía y asesoría técnica para la Comisión Federal de Electricidad (CFE) y Petróleos Mexicanos (PEMEX). En 2012 ingresó a la Gerencia de Turbomaquinaria. Sus áreas de especialidad son la simulación de procesos, análisis de sistemas de gene-ración eléctrica y cogeneración, así como la evaluación y diagnóstico de sistemas energéticos. Actualmente trabaja en el diagnóstico energético de la refinería de Cadereyta, Nuevo León, México. Es autor de varios artículos nacionales e internacionales. Miembro del Sistema Estatal de Investigadores (Consejo de Ciencia y Tecnología del Estado de Morelos) desde 2009.

De izquierda a derecha José Hugo Rodríguez Martínez y Luis Iván Ruiz Flores.

Documents

Boletín IIE julio-septiembre-2012 Artículo de ... · the 13.8 kV to 34.5 kV BS in two refine-ries from the north of Mexico, and 1 elec-trical upgrading of 13.8 kV to 115 kV in one