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© 2012 Invensys. All Rights Reserved. The names, logos, and taglines identifying the products and services of Invensys are proprietary marks of Invensys or its subsidiaries. All third party trademarks and service marks are the proprietary marks of their respective owners. Integration of Dynamic Simulation with Mechanical Integrity Study Steven Sendelbach – Principal, Dan Weidert – Process Engineering Manager, Using DYNSIM to ensure Operations consistent with Long-term equipment life

Slide 3 Who is Chart? Ch Art Energy & Chemicals Division Design and Manufacture Multi-stream Heat Exchangers Process Licensor – LNG, NRU (featuring Multi-stream Heat Exchangers and Cryogenic Processes) Principle NA Energy & Chemicals locations: La Crosse, Wisconsin (Brazed Aluminum Heat Exchanger (BAHX) Design & Manufacturing) Tulsa, Oklahoma (Air Cooler Design & Manufacturing) New Iberia, Louisiana (Cold Box Manufacturing) The Woodlands, Texas (Process Technology and Process Engineering)

Slide 4 Chart’s LNG Process Features: State-of-the-art Multi-stream BAHX IPSMR ® (Integrated Pre-Cooled Single Mixed Refrigerant) Systems where composition management is critical to achieving design performance The Benefits of the Chart LNG Process: Material of Construction – Aluminum, offers: Superior heat transfer properties Lighter weight Smaller footprint Low investment relative to traditional Spiral Wound Heat Exchangers

Slide 5 More on Chart’s LNG Process The experience: ‘Installed’ experience is less than that of the competition Fending off ‘Sales & Marketing’ seeds planted by competitors ALPEMA (Aluminum Plate Fin Heat Exchanger Manufacturer Association) Maximum T between passes <= 28 O C Cool down at a rate <= 2 O C per minute (Chart uses 1 O C per minute) Repeated deviation of ALPEMA guidelines will impact service life of a BAHX

Slide 6 Plate-Fin Construction A layer type is a unique combination of fins and bars. Layer types are configured to meet customer “pinch” composite temperature profile. Layer types are very flexible.

Slide 7 Plate-Fin Construction Layer arrangements stack unique layer types to an optimal combination. Between each layer type is a parting sheet. Layer types exit the matrix at different locations so streams do not mix. Entrance and Exit openings are called ports or distributors.

Slide 8 Chart Plate-Fin Heat Exchangers Chart Energy & Chemicals manufactures plate-fin heat exchangers in La Crosse WI.

Slide 9 BAHX Manufacturing - Stacking

Slide 10 BAHX Manufacturing - Furnace

Slide 11 An Ideal candidate for Dynamic Simulation Uses sophisticated simulation technology (DYNSIM) along with advanced heat transfer technology (Chart) to demonstrate real process performance to clients Allows Chart to answer detailed questions (about controls and operations) with a high degree of confidence and put client concerns to rest Helps us all understand the safest way to operate within ALPEMA guidelines, maximizing equipment life

Slide 12 LNG Implementation in DYNSIM For accuracy, need multiple MSHE objects to allow for different feed/product points along the length of the BAHX In different applications, have modeled as many as 200 finite elements for heat transfer – purpose is to get a good measurement of T at any point in the BAHX Configured an Excel Engine to plot the temperature curves and Maximum T curve as a function of location in the BAHX in real-time

Slide 13 What Chart Learned Along the Way … Matching the ‘design’ conditions proved to be extremely difficult Why??? Clearly, we have made some poor assumptions Time to speak with our colleagues in La Crosse where the BAHX are designed and manufactured

Slide 14 The La Crosse Contribution… Many streams undergo phase changes in the BAHX at different locations in each pass leading to heat transfer coefficient changes within each pass Use of average heat transfer coefficients across an entire ‘pass’ was just not good enough This level of detail is part of the mechanical engineering design of the BAHX – in the absence of this information, the resulting model is no better than an approximation But using this information will take the model from training simulation quality to engineering study quality With this approach (the La Crosse contribution), we are consistently able to match design operating performance of BAHX in DYNSIM Leads to creation of zones (sometimes more zones than geometrically required)

Slide 15 A Typical BAHX – Guidance for Zones

Slide 16 Example of Temperature Curve

Slide 17 Example of Maximum T Curve

Slide 18 and, By Way of Comparison from PRO/II A form of validation of the dynamic model at the design steady state operating condition

Slide 19 Some Findings… Base line control and ESD strategies would expose BAHX to high Ts between passes Use DYNSIM to modify controls and prototype alternate control strategies to eliminate operating conditions which may lead to high Ts between passes in the BAHX

Slide 20 Evaluate the Cause and Effect Logic, as designed… For loss of MR at compressor suction, Maximum T between passes may reach as high as 60 O C To comply with ALPEMA guidelines, When the MR Compressor goes into total recycle, there is no refrigerant flow in the BAHX If there is no refrigerant flow in the BAHX, then the Treated Gas Flow must also be stopped (add Feed ESDV to the Cause & Effect Logic) The consequence of this change is that the maximum T will be in the mid 20 O C range

Slide 21 Loss of Compressor Suction

Slide 22 A Closer Look at the High T

Slide 23 And After Modifying the Cause & Effect Logic …

Slide 24 Conclusions With detailed engineering design data, it is possible for Chart to manage equipment life by Having a closer look at what happens inside the BAHX during transients Properly configuring control logic to operate equipment within constraints (and not just traditional equipment like Compressors which are ‘normally’ protected) Demonstrating to clients the impact of control and operating changes to make most effective use of their investment

Slide 25 Thank You