by Apros simulation Fuel Characterization Workshop Jyvskyl, 23 rd - - PowerPoint PPT Presentation

Utilisation of results from pilot and bench scale studies by Apros simulation

Fuel Characterization Workshop Jyväskylä, 23rd September 2014 Matti Tähtinen VTT Technical Research Centre of Finland

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Contents

• Presentation
• The utilities and targets of modelling
• Quick introduction to Apros Combustion
• Utilisation of experimental data in modelling
• Recent project examples
• Conclusions

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Utilisation of experimental data in Apros simulation

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Where modelling is utilised?

• Modelling programs provide an environment for process

simulation models

• With process models can be evaluated:
• Process phenomena
• Optimize production of the plant by evaluating process connection

points and alternatives before building the plant.

• Use as a training simulator before the new plant is ready
• Use as design and testing environment
• Use as an analysis tool
• Find process problems

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Steady state vs. Dynamic simulation

• Terms:
• Steady state = Simulation which is executed once. Program

calculates once and gives results according to initial data.

• Dynamic = Time depending simulation, where initial data can be

changed during simultaneously calculation. Results are also changing during the simulation.

• Apros Combustion is dynamic process simulation software

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Dynamic process simulation

Integrated process level Basic component level

Elementary components branches, nodes, structures, sources

Process component level Conservation equations for mass, momentum and energy

Control circuits Logic circuits Sequences Change-over automation Measurements Device controls Actuators

Set points

Position

The automation can be included in the model ... Or real/virtual automation application can be connected to the process model.

Control system model Process model

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Simulation Information Management Engineering Information Management Simulation Engineers Design Engineers

Simulation and process design integration

Plant design systems: SmartPlant Foundation, Comos, … 3D design Process design Automation design

Simantics

Apros Process Simulation Common user interface environment Other simulators: Balas, DEVS, sd, Fluent, Modelica, company specific

Process simulation

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Apros modelling program

• Dynamic modelling program
• Included processes components (pipes, heat exchangers,

pumps, fans, valves and vessels etc.)

• Includes automation and instrumentation (controls, switches,

motor drivers, calculations etc.)

• Includes electrical systems
• For every block dimensions has to be defined. For example for the pipe-block needs to

be defined cross-section area, length, flowing material and nominal flow

• The blocks are combined together with so called calculation nodes and pipes which is a

basis of all calculations

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Utilisation of experimental data in Apros simulation

Utilisation of experimental data in modelling

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Experimental combustion at VTT

GRATE COMBUSTOR (100 kW)

Secondary air FUEL Fuel feeder Cyclone

FLUE GAS FLY ASH

DISTRICT HEAT District heat exchanger Primary air Tertiary air PC control and data logging system Rotating grate

BOTTOM ASH

Fuel and additive feed Bottom ash Flue gas recirculation Riser Solids circulation sample Gas tanks

(air, N2, CO2, O2)

Loop seal material sample Temperature, pressure and profile sampling along the combustor height Primary cyclone Secondary cyclone Deposit probes Gas cooler Bag house filter Flue gas to stack Secondary and tertiary airs Primary air and grid

Bench scale CFB/BFB (0.1-1.0 kW) Pilot scale CFB/BFB combustors (15-100 kW) Pilot scale grate combustor (100 kW)

• Bench scale (CFB/BFB) for reactivity, bed material analysis, fuel/material screening
• Pilot devices for process dynamics, heat exchange, scale-up, fouling, etc.

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Apros CFB boiler development

• VTT has long background on furnace modelling
• CFB and BFB furnace model to Apros
• CFB/BFB pilot experimental data combined to dynamic

furnace model and implementation to Apros

• Combustion and hydrodynamics etc.
• Combination of furnace model and Apros to provide scalable

information for power plant

• More accurate dynamic simulation of process

1 n n+1 2 n-1 3 n-2 1 n n+1 2 n-1 3 n-2 1 n n+1 2 n-1 3 n-2 1 n n+1 2 n-1 3 n-2 1 n n+1 2 n-1 3 n-2 1 n n+1 2 n-1 3 n-2 1 n n+1 2 n-1 3 n-2 1 n n+1 2 n-1 3 n-2 1 n n+1 2 n-1 3 n-2 1 n n+1 2 n-1 3 n-2 1 n n+1 2 n-1 3 n-2 1 n n+1 2 n-1 3 n-2 1 n n+1 2 n-1 3 n-2 1 n n+1 2 n-1 3 n-2 1 n n+1 2 n-1 3 n-2

1D dyn. CFB model

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Boiler

• Boiler and turbine models include:
• Fuel, sand and limestone feeding
• Oxygen feed
• Furnace
• All the heat exchangers of the water-/steam circulation
• Steam turbine including HP-, IP- and LP-parts
• Main condenser and main cooling pump
• Condense water preheating
• Feed water tank and pump
• Feed water HP-preheating

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Combination of different process parts

APROS

CFB boiler Turbine and steam cycle

Matlab SIMULINK

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Apros-model: Boiler, air pre-heat and fluegas heat recovery

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Apros-model: Boiler and steam cycle

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Apros-model: Turbine and feedwater pre- heating

Recent project examples

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EU-project Flexi Burn CFB (2009-2012)

• Combines experimental pilot tests at Jyväskylä VTT, steady state and dynamic simulation.

To produce enough information for 30MW demo plant at Spain

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Utilisation of experimental data

• Flexi burn:
• Dynamic once through CFB boiler was modelled by Apros

(300MWe).

• This boiler can be driven both in air and in oxy mode
• Dynamic oxygen production- (Air Separation Unit, ASU) and

carbon capture plants (CCS) were modelled by Aspen

• Apros and Aspen were combined together by using Matlab

Simulink –program

• All these plants were simulated at the same time to test:
• Load changes
• Switching from air over to oxy firing and back
• Special situations like feed water pump stop, fuel feed stuck, oxygen

feeding stops etc.

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Utilisation of experimental data

• O2GEN:

Flexi burn –project follow-on project where:

• Oxygen content in recirculation gas is increased
• The boiler construction research because of the increased of O2:

advantages – disadvantages

• Heat capacity increasing has to be remarked in boiler construction.
• Apros is used for modelling a dynamic oxygen fired CFBC

(600MWe) and a steam turbine

• Aspen is used for modelling a dynamic O2- production and CO2-

purification plant.

• All these plants will be simulated at the same time to test:
• Load changes, process optimisation, upper level controls, etc.

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Utilisation of experimental data

• Sandwish:

Combination of a concentrated solar power and CFBC

• Apros is used for modelling a dynamic air fired once through boiler

(OTU 460MWe) and a steam turbine

• Apros is used for modelling solar field. Linear Fresnel and

Parabolic trough are the alternatives for solar field

• From real life collected sun radiation data can fed into the solar

field or solar irradiation can be simulated

• The models are combined and from the solar field achieved hot

steam is lead into the boiler

• Turbine tapping's are substituted with solar field steam

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An example of a modelled case: Coal plant evaporator analysis

• Target: 315 MW pulverized coal power plant of Fortum,

located in Naantali, Finland. Origin in the 1970’s.

• Motivation: Suffered of evaporator tube damages. Recent

change in control strategy. Does the new way increase risk for tube ruptures?

• Approach in modelling: detailed model of the evaporator

tubes, minimum scope of the surrounding process, rough model of the combustion heat power

• Analysis of the temperatures of the individual tubes when

different operational scenarios are practised

Ref: Lappalainen, J., Blom, H, Juslin, K., Dynamic process simulation as an engineering tool – A case of analysing a coal plant evaporator, VGB Powertech, 1/2 2012, pp. 62-68.

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Conclusion

• VTT has powerful modelling tools for researching, analysing,

design and testing

• Apros is capable to dynamic evaluation of large process

integrations

• At VTT there are made several years process modelling in different

kind of projects

• Customers are very satisfied with project results
• In the future we will focus on:
• Apros furnace model development
• Boiler and process heat integrations
• Combined use of the solar field power and boiler
• Control development for any integration to provide optimum operation

conditions

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