Current Steam Turbine Technology and its Applicability in the Pulp and Paper Market

Transcription

1 Current Steam Turbine Technology and its Applicability in the Pulp and Paper Market Manuscript The pulp and paper industry in the United States and Canada has been a strong part of the economic landscape in this region since the early 1900 s, in large part due to the increase in global demand for the products provided by this industry during this time period. The industry saw major investments in the 60 s and 70 s, and however competition from other global competitors and general market shifts during the past 20 years has led local companies to make changes in their operations, to ensure their competitiveness in the market. For many of the mills, steam and the use of steam turbines forms an integral part of the process and plant needs. As companies seek to improve the production of their facilities, be it by efficiency improvements, process optimizations, expansions, replacements for obsolescence, mill consolidations, or operational improvements, the understanding of current options available in steam turbine technology and other associated market offerings can be beneficial for such evaluations. Steam turbines are generally considered a mature product in the industry technology that has been in operation for over 100 years. However, the current market offers features, design advances, and operational monitoring concepts that are available to provide improvements in efficiency, product/process capabilities. These options can be evaluated by customers for any type of improvement or expansion projects for their facilities, and are available for existing turbine modifications, product/module replacements, and new turbine generator sets. The presentation associated with this document will provide an overview of these features and concepts, and where applicable where they could be implemented by customers. It will also include an example of such implementations in the pulp and paper industry.

2 Overview Market o Challenging demand for paper, competition from overseas o Mergers and Acquisitions Lower number of facilities Process changes o Market changes and time lead to changes in process Adjustments to the facility, vs. original design, mean suboptimal process Facilities many > 30 years o Equipment obsolescence, maintenance, replacement needs, etc. o Changes to the facility lead to suboptimal process design Steam Turbine Technology o Blading 1-2% improvement o Adaptive Stages o Seals o Thermal conditions Turbine options o Why consider: Modify to adapt to new conditions OEM knowledge availability? o Revamp Adv Use existing unit Adapt to new plant conditions Take advantage of updated available technology (blades, seals, etc.) Lim Adaptability limited by existing turbine casings and generator Turbine life extension o Footprint Complete module or hardware replacements work to match existing footprint, auxiliaries, etc Replace OOEM. Provides more adaptability to changes in process o New unit Requires all new equipment, modification to existing foundation or new foundation New equipment guarantees, year life Complete adaptability to new process conditions OEM service and support availability o Generator Not usually considered Shift from H2 to Air cooled generator savings in service Depends on the life of the generator Services monitoring and long term service agreements Case Study Port Wentworth Summary

3

4

5 Steam Turbines and the Pulp and Paper Industry Unrestricted Siemens AG 2017 All rights reserved.

6 Overview Overview Steam Turbine Technology Available Options Available Services Case Study Summary

7 Market Overview Pulp and Paper industry has been a strong part of the economic landscape in North America Market drivers has led to changes in the industry Global competition Paperless Society Mergers/Acquisitions

8 Pulp and Paper Facilities Significant investment in facilities in the 60 s and 70 s Market and technology evolutions leads to changes in process Market drivers impact the targets for the facility Technology changes in the facility can impact the original process scheme Equipment age and obsolescence The changes in the market can have a direct impact to the existing facilities.

9 Steam Turbine Technology Overview Turbine Development Drivers Industrial and Power Market Changes Consolidations/Knowledge Transfer Operating Fleet Experience

10 Steam Turbine Technology Overview Blading Technology Traditional Blading Technology Cylindrical Profiles Initially Designed for Manufacturability and Assembly Current Blading Technology 3DV Profiles Improve efficiency Overall impact of efficiency for Blade Path 1-2% Adapted to current engineering and manufacturing processes Adaptation of utility based last stage blading tech in industrial applications

11 Steam Turbine Technology Overview Sealing Technology Steam through blade creates power Steam through sealing does not create power Contactless labyrinth shaft seals Brush Seals Reduction of leakages increases efficiency More and better sealing strips per blade row Adapted to shaft/end seals

12 Steam Turbine Technology Overview Stationary/Rotating Design Technology Traditional Designs Robust Design methodology of the time based on available tools, material knowledge, etc. Current Capabilities Modern methodologies allow optimized designs Able to meet design life and provide more operational flexibility Modern design methodologies allow for a turbine design optimized to the application needs

13 Steam Turbine Technology Overview Extraction Capabilities Adaptive Stage Internal Valves Up to 6 extractions/bleeds in total Controlled extractions (maximum 2, up to 72 bar/1044 psi) External and internal valves Adaptive stages Grid valves Uncontrolled extractions/bleeds External Valves Grid Valve Adaptable to meet any process need

14 Steam Turbine Technology Overview Thermal Conditions Capabilities Current Capabilities Inlet pressures up to 165 bar (2393 psi) Inlet temperatures up to 565 C (1050 F) Backpressure designs up to 80 bar (1160 psi) For condensing applications, any application < 1 bar (14.5 psi) Industrial turbines can meet current thermal parameters in the world wide industry

15 Steam Turbine Options for Consideration Modification and Upgrade (i.e., Revamp) Update to internals/rotors of existing turbine Normally keep turbine external casings, auxiliaries, etc. Footprint Replacement Turbine module or major hardware replacement, maintaining original turbines interface points, auxiliaries, etc. New Turbine or Turboset Turbine module replaced with entirely new turbine, often requires new auxiliaries and systems (lube oil module, hydraulic valve system, etc.) Normally entire turboset (ST and GN) replaced, however can consider only turbine if necessary

16 Steam Turbines Other aspects to consider Generators Many operating units (> 30 years) using hydrogen cooled generators Current technology for most generators < 300 MWs is air cooled Evaluate further lifetime extension or replacement Service Options Long term service programs Online monitoring of turbines, OEMs provide support to the facility, service programs, etc. to help ensure facility availability for the customer

17 Case Study Pulp Facility in USA Pulp and paper facility in the Southeast of the United States. Plant originally designed for pulp and paper production, Hog and recovery boilers sized for full production, running two steam turbines, Acquired by current owner in the late 90 s Previous owners removed the paper machines No modifications to plant at the time, overall process running at part load (suboptimal) backpressure turbine only running at 50% of rated load Parent company performed plant evaluation, options to modify plant to meet current configuration Decision in 2014 to perform changes boiler super heater upgrades, turbine inlet header up to 1200 psi, and a complete steam turbine module replacement New backpressure turbine with capability of 1200 psi header pressure, controlled extraction - but kept existing H2 generator Increased header pressure improved overall cycle efficiency, and the recovery of the lost 20 MWs was used for sale to the local utility

18 Summary Evaluate the current state of the facility Steam audits, facility evaluations, etc. can lead to ideas for potential benefits Evaluation of the local market also important as part of the overall financial impact Consider the currently available technology and options Each facility s process needs are unique Technology exists to match practically every process option and operational profile If there is a potential benefit identified, engage the OEM These are all engineered solutions the final identified configuration may be very different from the original intent! OEMs can bring a perspective of how the equipment and technology behave that can greatly enhance the overall evaluation!

19 Questions? Unrestricted Siemens AG 2017 All rights reserved.