NEW 660 MWe UNIT WITH SUPER- CRITICAL STEAM PARAMETERS IN THE LEDVICE POWER PLANT

Transcription

1 NEW 660 MWe UNIT WITH SUPER- CRITICAL STEAM PARAMETERS IN THE LEDVICE POWER PLANT WE DO BIG THINGS

2 A WORD OF INTRODUCTION

3 ŠKODA PRAHA Invest was given a unique opportunity to prove its best abilities as an EPC contractor and designer of large power generation projects with the project of a new unit with supercritical steam parameters in the Ledvice power plant. The project was also a chance to prove that the experience from the executed projects represented by 40,000 MW of installed capacity around the world has provided us with the best knowledge and abilities that we transform into the execution of this project and that the principles of the best applicable technology and environmental friendliness are not just empty words for us. Ing. Daniel Jiřička General Director ŠKODA PRAHA Invest WE DO BIG THINGS

4 ABOUT THE LOCATION The Ledvice power plant is located at the foothill of the eastern part of the Krušné hory mountain range, between the spa towns of Teplice and Bílina. The original power plant was constructed between 1966 and 1969, with the power output of 640 MW. After fi nalization of the construction managed by ŠKODA PRAHA, a predecessor of the current EPC contractor, the power plant consisted of fi ve power generating units with power outputs of 200 MW (unit 1) and MW (units 2 5). Operation of the unit no. 5 ended in February 1994, followed by the unit no. 1 at the end of the year A complete overhaul of the turbine and installation of a new fl uidized bed boiler took place from 1996 to 1998 on the unit no. 4. ABOUT THE PROJECT CONSTRUCTION OF THE NEW 660 MWE UNIT WITH SUPERCRITICAL STEAM PARAME- TERS IS CONDUCTED BY THE EPC CONTRACTOR, ŠKODA PRAHA INVEST. The new 660 MWe unit in the Ledvice power plant (NU) was designed as a state-of-the-art solid fuel unit with a large power output, in accordance with recommendations of the European Union Best Available Technology standard; the unit with the largest economically reachable energy effectiveness and lowest possible negative impacts to the environment. It was, therefore, necessary to reach the maximal possible operation parameters and minimize the emissions. The new unit is designed as a single unit design with one boiler featuring supercritical direct steam parameters and a four-stage steam condensation turbine. The unit is of a compact alternative, with a clean gas duct routed to the cooling tower. The location in the existing Ledvice power plant was proposed for construction of this unique plant on the basis of a geological survey. The new unit will use coal from the adjacent open-pit brown coal mine in Bílina. The units nos. 2 and 3, which are near to the end of their operational lifespan, will be shut down together with the start-up of the new unit and the 4 th unit with the fl uidized bed boiler will remain in operation along with the new unit.

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6 3D ARCHITECTONIC MODEL OF THE NEW UNIT CONTROL CENTRE VISUALISATION

7 PROJECT OBJECTIVES Construction of the new unit with supercritical steam parameters, a unique project in the Czech Republic, was awarded by ČEZ, a. s., the investor, to ŠKODA PRAHA Invest s.r.o., the EPC contractor. The project objective was to acquire a new production unit in the existing Ledvice power plant by the means of construction of a new power plant unit with a 660 MWe rating. The proposal of the civil and technological solution that will secure an economically effective operation of the unit throughout the complete operational lifespan of the power plant, meeting all legal requirements and using the best available technology, was crucial. The expected net efficiency of the new unit will reach 42.5%. DESIGN AND PREPARATION STAGE ŠKODA PRAHA Invest is not only the EPC contractor of the complete project but it is also its chief designer. A construction project elaborated by the investor was the basis for preparation of the design. The subsequent technical solution of the whole project including the time schedule was already done by the ŠKODA PRAHA Invest design team. We have dealt with the task of finding the optimal technical solution, unlike others, also from the point of view of the progress of work in the fi rst stage of the project with a minimal impact to operation of the existing units. Another vital project task comprised division of the project into the individual commercial packages and elaboration of the technical and commercial part of specifi cations of the competitive tendering procedure for selection of suppliers of these commercial packages. One of the main tasks of the EPC contractor was coordination of the design documentation so that all equipment is properly connected and creates a functional system throughout all commercial packages. Modern software tools were used to manage the challenging design coordination of the new unit. This is mainly the case of PDMS software which was used to create a 3D database model of the power plant. The resulting effect came with preparation of clash reports identifi cation of the collision between individual suppliers and also in the course of preparation of the design documentation. Another advantage is the complete digital model of the power plant which will be provided to the investor after completion of the work, and which could be used for future maintenance. The buildings and equipment were designated by the KKS, a unified power plant designation system. Another vital tool for the coordination is the drawing of the complete site, i.e. its layout. The layout is updated together with the project requirements. The change overview spreadsheets, lists of civil objects and KKS designation form a part of the drawing documentation. Incorporation of the requirements and requests of the customer was vital during the design stage. An example of this interactive cooperation was the design of the control centre through visualisation.

8 TECHNOLOGY AND CONSTRUCTION BASIC PARAMETERS Electrical power output 660 MWe Effectiveness 42.5% Critical piping 28 MPa/5 MPa Steam temperature 600/610 C Steam volume 1,684 t/h CIVIL PART OF THE MAIN PRODUCTION UNIT Execution of the civil part of the main production unit represented use of 120,000 m 3 of concrete, 22,000 tons of steel, 20,734 m of reinforced concrete piles (887 pieces) and 2,111 m 2 of construction pit reinforcement walls. The boiler house consists of one storey of a m concrete basement with a boiler steel structure erected on the top of it. The boiler foundation slab rests on 560 high diameter piles. Four massive columns are the foundation for the steel structure. The boiler pressure parts are hanged on the main steel structure. PROGRESS OF CONSTRUCTION WORKS AT THE MAIN PRODUCTION UNIT IN TIME

9 Two towers with dimensions of m were erected on the basis of the sliding formwork technology. The concrete works were done continuously 24 hours a day, 7 days a week. BOILER The 141 m high tower boiler is supplied by ALSTOM Power Systems. It is a pulverized coal tower boiler. The boiler will be equipped with eight ventilator mills with the capacity of 72 t/h, hydrodynamic coupling regulation of their revolutions, ventilation effect, and thus the fl ue gas outlet speed downstream the mill. Seven mills are suffi cient for operation of the unit at its nominal power. FUNDAMENTAL DEFINING SPECIFICATIONS OF THE BOILER: Pulverized coal tower boiler (8 pulverized coal ventilator mills with 72 t/h capacity) Height: 141 m Feed water pressure: 280 bar Superheated steam volume: 1,684 t/h Superheated steam temperature: 600 C Reheated steam temperature: 610 C Gross effi ciency: 47% Lowering of the CO 2 and NO x emissions Lowering of the operation costs Operational lifespan: 40 years

10 TURBOGENERATOR The steam turbine supplied by ŠKODA POWER is a tandem compound type turbine. The turbine consists of one single stream HP part, one double stream IP part and two double stream LP parts of the Diabolo type. That means that two low pressure turbine parts are provided with an inlet in the middle of the casing and the steam in individual stages is expanding symmetrically in opposite directions alongside the axis; the steam from the fi nal impeller is routed through four outlets into two separate condensers. The turbine is a condenser, reheated type with nine regeneration outlets and three unregulated outlets for heat supply. The regeneration consists of fi ve LP reheaters and three HP reheaters. New heat resistant steels developed within the scope of the European COST programmes, which are able to withstand temperatures over 600 C, are used for the 660 MWe turbine with supercritical steam parameters. MAIN STEAM TURBINE COMPONENT MATERIALS: Valve chambers: G-X12CrMoVNbN9-1 HP and IP casing: G-X12CrMoVNbN9-1 HP and IP rotors: X14CrMoVNbN10-1 LP rotors: 27NiCrMoV15-6 HP impeller blades: Bohler T550 IP impeller blades: Bohler T505SC LP impeller blades: Bohler T671 Bolts: Inconel 718 PROGRESS OF THE CONSTRUCTION OF THE COOLING TOWER IN TIME

11 STEAM PIPING As the new unit in the Ledvice power plant is the first power plant in the Czech Republic featuring supercritical steam parameters, use of completely new materials and technologies proved to be necessary. The high quality X10CrWMoVNb9-2 alloy steel was used for the superheated steam piping and X10CrWMoVNb9-2 for reheated steam piping and forged fi ttings with a spherical shape main casing to provide maximal effectiveness of utilization of the mechanical qualities of the steel. The design of the main pipe routes comprised optimization of the pipe wall thickness in relation to the pressure and heat stress and requested system operational lifespan. All the calculated procedures and results were discussed and approved by the respective supervisory institutions (TUV). Note: HP = high pressure IP = intermediate pressure LP = low pressure

12 ECOLOGY The unit is designed as environmentally friendly as possible. Wet limestone scrubbing was selected for the fl ue gas desulphurization, having the highest operation effectiveness. Flue gasses with almost all dust particles caught in the modern electrostatic precipitators are routed to the scrubber, where they are cleaned by limestone slurry at four spray levels. Limestone slurry reacts with the sulphur oxides, binds them and is transformed into gypsum slurry. The remaining ash in fl ue gasses is caught by the spray levels, along with other harmful compounds, such as those of fl uorine and chlorine. Cleaned fl ue gases are routed into the cooling tower where they are discharged into the atmosphere together with evaporated cooling water. Blowdown water from the cooling towers with an increased salt content is used for replenishing of process water in the scrubber and removal of slag from the boiler. Most of the waste water from the desulphurization, chemical water treatment from demineralised water production and from the boiler is used for mixing in the solid waste material mixing centre. All produced ash and slag will be processed in the mixing centre together with additional substances, forming the stabilized mixture, which will be transported through piping and high pressure pipes to the excavated parts of the coal mine, where it will be deposited. Produced solidifi ed materials have a low dissolution level of components and chemical elements. In layman terms, this material will not release fl y ash or chemical elements that could contaminate the soil or ground water.

13 FUNDAMENTAL GUARANTEED EMISSION VALUES OF THE DISCHARGED FLUE GASSES: NO x < 200 mg/nm 3 (6% O 2 ) SO x < 150 mg/nm 3 (6% O 2 ) CO < 200 mg/nm 3 (6% O 2 ) Ash particle content < 20 mg/nm 3 (6% O 2 )

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15 INTERESTING FACTS ABOUT THE PROJECT The new power plant unit will be the first supercritical unit in the Czech Republic. The boiler house building (north tower lookout) with its 143 meters will become the tallest building in the Czech Republic. Civil works followed the accelerated action time schedule and the construction site was handed over to the boiler and desulphurization suppliers in advance. The heaviest piece of equipment, the stator of the generator weighing 330 tons, was transported to its position in September 2010.

16 IMPLEMENTATION THE PROJECT IS DIVIDED IN TWO IMPORTANT STAGES: Release of the construction site (dismantling of the existing buildings at the area of the new unit, assembly of the replacement buildings for the continuous operation including adjustment of the existing buildings); Erection of the new unit. Two thirds of the existing administration building, original chemical water treatment and old parts of the coal handling bridges were dismantled and the coal yard was transferred away from the existing units so that the new desulphurization unit and connected process buildings could be built in its place. Kilometres of the existing engineering networks in the power plant area were relocated. This relocation was fi rst designed, then executed and fi nally the original piping and cables were removed so that they do not obstruct the planned construction. Some buildings and the process equipment had to be newly constructed by the ŠKODA PRAHA Invest team (due to the location of the power plant), all with the parallel operation of the 3 existing units. This matter was related mainly to the administration building, chemical water treatment and coal handling. Another notable complication during the execution of release of the construction site was the extensive underground infrastructure and limited area for the construction itself. However, construction of the new power plant main production unit started in January 2009 after dismantling and erection of new replacement buildings and in February 2010 the site was handed over for the purpose of starting assembly work on the boiler. EXECUTION PRIORITIES PRIMARY EXECUTION PRIORITIES FOR THE NEW UNIT: 1. Following the occupational safety, health and environment protection rules 2. Quality 3. Time schedule 4. Budget MANAGEMENT SYSTEMS OF THE IMPLEMENTATION FULFILMENT OF THE OCCUPATIONAL SAFETY, HEALTH AND ENVIRONMENT PROTECTION RULES IS THE HIGHEST PRIORITY FOR ŠKODA PRAHA INVEST DURING THE CONSTRUCTION PERIOD. The following fundamental principles of environmental protection were observed in the construction site rules in the course of project management: Water protection and spill prevention Handling of dangerous chemicals Waste handling

17 BOILER RAW GAS DUCT ASSEMBLY

18 ASH STORAGE ASSEMBLY

19 In order to meet the occupational safety and health protection requirements a training room, in which trainings take place in 10 different languages, was established. All construction site personnel underwent this training prior to their access to the site. There is a zero tolerance towards addictive substances. All personnel entering the site shall be provided with working clothes and footwear, a protective helmet and a refl ex west equipped with a logo. Each place of work has a designated occupational safety and health protection coordinator and a technician who is to organize regular weekly inspection days and conduct continuous site inspections. Each place of work is also provided with an updated occupational safety and health protection plan at its entrance. Access to all places of work is regularly updated for the purposes of the Integrated Rescue System. QUALITY OBJECTIVES STIPULATED IN THE QUALITY PLAN ARE SPECIFIED FOR THE PROJECT. Fulfi lment of the customer s requirements Reaching of the operational lifespan of the new unit Fulfi lment of the guaranteed parameters High operational availability Compliance with the technological discipline Capability of the new unit to operate at limit conditions Meeting of the project budget QUALITY PLAN INPUTS Requirements stipulated in the EPC contract for work Requirements stipulated in the quality management system Requirements of the Czech EN ISO 9001 Standard Requirements of the Czech EN ISO Standard The Critical Path Method (CPM) is used in all project stages for the purpose of planning of the time schedule and project management. Weekly and monthly reports are regularly submitted with an updated time schedule or S-curves containing a visual representation of selected construction progress values. Economic indicators are also continuously monitored and presented to the customer at regular progress meetings held by ŠKODA PRAHA Invest. SITE EQUIPMENT AND COMMON SITE EQUIPMENT The Site Equipment and Common Site Equipment were prepared together with the release and preparation of the construction site by ŠKODA PRAHA Invest, the EPC contractor. The concept for the Site Equipment and Common Site Equipment were elaborated in the Site Organization Project in order to correspond with the site requirements to the maximum possible extent. The main objectives related to creation of the Site Equipment and Common Site Equipment are as follows: Preparation of the Site Equipment and Common Site Equipment as a controlled process managed by the investor and EPC contractor; Securing of suffi cient capacities for the site facilities, thus allowing for a smooth completion of suppliers work; Maximal utilization of the limited area potential at the Ledvice power plant; Preparation of the Site Equipment and Common Site Equipment considering the future possibilities for their utilization after completion of the process of construction of the new unit. Mobile construction containers were installed at selected areas in order to be used as offi ces, locker rooms, lodging and mess halls. All of the aforementioned tasks were completed considering the objective of meeting the peak capacity in the planned workforce histogram (2,500 workers).

20 CONCLUSION

21 Completion of the new unit in the Ledvice power plant represents integration of the Czech Republic into the group of countries featuring the latest trends in electric power production. The role of the EPC contractor of this unique project is both a challenge and honour for ŠKODA PRAHA Invest. Preparation and construction management, coordination of all suppliers, successful management of the interface between the operated units and site as well as emphasis on the health and environmental protection all the aforementioned aspects represent highly challenging requirements for ŠKODA PRAHA Invest, which have been coped with successfully.

22 VISION IS THE FIRST STEP TO ACTION

23 WE ARE AN EPC CONTRACTOR AND DEVELOPER OF INVESTMENT PROJECTS IN THE ENERGY SECTOR We are the largest Czech engineering contractor able to deliver power generation projects from the design through implementation and assembly to commissioning and securing of both warranty and extended warranty service. We also supply balance of plant. We provide service tasks. We are active primarily in conventional and nuclear power, but also in heating plants, CCGT power plants and renewable energy sectors. We are implementing the Czech industrial project of the decade, the Renewal of the ČEZ Group production capacity. As part of this project we are performing the comprehensive and environmentally benefi cial renewal of the Tušimice II and Prunéřov II power plants; we are constructing a new production unit with supercritical steam parameters in the Ledvice power plant and a new CCGT plant in the Počerady power plant. We are also implementing complex delivery projects for nuclear power plants as well as output improvement projects and nuclear unit modernisation. We also operate in the fi eld of renewable energy sources. We excel in a strong professional know-how that we have been building under the ŠKODA PRAHA trademark for 60 years. During that time, we have delivered more than one hundred power generation units with a total output of 40,000 MW to 25 countries around the world. We deliver energy generation works that stand out due to their high technological quality, effi ciency, reliability, and are environmentally friendly. WE DO BIG THINGS

24 NEW 660 MWe UNIT WITH SUPERCRITICAL STEAM PARAMETERS IN THE LEDVICE POWER PLANT April 1, WE DO BIG THINGS