Dynamic Simulation of Opposed MultiDynamic Simulation of Opposed Multi--Burner Burner CoalCoal--Water Slurry Gasification SystemWater Slurry Gasification SystemCoalCoal Water Slurry Gasification SystemWater Slurry Gasification System

Zhenghua Dai* Junyu Yang Chao LiZhenghua Dai* Junyu Yang Chao LiZhenghua Dai , Junyu Yang, Chao Li, Zhenghua Dai , Junyu Yang, Chao Li, Guangsuo Yu, Fuchen WangGuangsuo Yu, Fuchen Wang

Institute of Clean Coal Technology(ICCT), Key Laboratory of Coal Gasification and Energy Chemical Engineering of Ministry of Education, East China University of Science

and Technology (ECUST), Shanghai 200237, Chinagy ( ), g ,

ContentContentContentContent

The introduction The introduction The d mamic model of Opposed M ltiThe d mamic model of Opposed M lti B rnerB rner The dymamic model of Opposed MultiThe dymamic model of Opposed Multi--Burner Burner

(OMB) Coal(OMB) Coal--Water Slurry Gasification SystemWater Slurry Gasification System Dynamic Simulation of Online ResetDynamic Simulation of Online Reset Dynamic Simulation of Online Reset Dynamic Simulation of Online Reset

Process(ORP)Process(ORP) operationoperation Dynamic Simulation of gasification temperature Dynamic Simulation of gasification temperature

Control Control Conclusions Conclusions

1. The introduction1. The introduction

The research field of dynamic system simulationThe research field of dynamic system simulationThe research field of dynamic system simulationThe research field of dynamic system simulation

The dynamic characteristic of unit equipmentThe dynamic characteristic of unit equipment The dynamic characteristic of unit equipmentThe dynamic characteristic of unit equipment The optimization of process parameter, especially The optimization of process parameter, especially

for whole system intergrationfor whole system intergration The design and validation of control scheme, The design and validation of control scheme, gg

especially for the whole system controlespecially for the whole system control The operation earlyThe operation early--warning and acident repeatwarning and acident repeat The operation earlyThe operation early--warning and acident repeatwarning and acident repeat Operation Train System (OTS)Operation Train System (OTS)

The review of dynamic simulation of coalThe review of dynamic simulation of coal

G ifi C t l S t

The review of dynamic simulation of coal The review of dynamic simulation of coal gasification systemgasification system

Gasifier Control System

Robinson and Luyben GE Y

Rory GE NCasella Shell YLee Shell NLee Shell N

Flexible RNM for a one- or two-stage gasifier with syngas cooling (Rory )g y g g ( y )

Flowsheet for approximate model(Robinson and Luyben)

2. The dymamic model of 2. The dymamic model of O d M ltiO d M lti B C lB C lOpposed MultiOpposed Multi--Burner CoalBurner Coal--Water Slurry Gasification SystemWater Slurry Gasification Systemy yy y

C ti i f th S h ti f ifi ti ithCross section view of the OMB CWS gasifier

Schematic of gasification process with OMB CWS gasifier

reactor network model (RNM) based on RTDreactor network model (RNM) based on RTD

Heterogeneous Reactions (the unreactedHeterogeneous Reactions (the unreacted--core shrinking core shrinking

reactor network model (RNM) based on RTDreactor network model (RNM) based on RTD

model)model) Simplified Flow Field (1500TPD, 6.5MPaG gasifier)Simplified Flow Field (1500TPD, 6.5MPaG gasifier)

Results Validation Results Validation

R id Ti V lid tiResidence Time Validation

Particle and gas state Comparison of gas and particle RTDParticle and gas state transition diagram for Markov

Chain

Comparison of gas and particle RTD for RNM and CFD

Comparison of industrial data and the steady state simulation results

ItemTemperature

(℃)

Carbon conversion

(%)

Mole fraction (dry basis) (%) Consumption1)

H2 CO CO2

m (Coal) (kg) V (Oxygen) Nm3

Comparison of industrial data and the steady-state simulation results

( ) Nm

Industrial data 1224 98.00 32.98 49.00 17.02 568 376

Simulation results 1238 98.02 33.58 51.00 14.91 562 373

D i d l f OMB ifi ti tD i d l f OMB ifi ti t Dynamic model of OMB gasification systemDynamic model of OMB gasification system

The steady model is transformed into the dynamic model which adopts pressure driven solution in UniSim software(Hysis)pressure driven solution in UniSim software(Hysis).

Simplified valve parameters of the pipe Simplified valve parameters of the pipe resistance (1500TPD, 6.5MPaG)resistance (1500TPD, 6.5MPaG)

Item Stream Flow Resistance Valve opening (kPa) (%)

VLV-1-1/2 CWS 35.66m3/h 50 50VLV 2 A/B/C/D CWS 17 85m3/h 2300 50VLV-2-A/B/C/D CWS 17.85m3/h 2300 50VLV-3-A/B/C/D Oxygen 8490Nm3/h 2411 50

VLV-4 Grey water 2.40×105kg/h 700 50

VLV-5 Black water 2.26×105kg/h 50 50

VLV-6 Syngas 2.46×105kg/h 100 50VLV-7 Syngas 2.46×105kg/h 50 50

VLV-8 Syngas 2.80×105kg/h 5700 50

Controller Description Kc I(min) Arrange Type Action

Parameters of the PID controllers Parameters of the PID controllers

Controller Description Kc I(min) Arrange Type Action

FC-C-1/2 Control the flow of CWS 0.5 0.3 9-43m3/h Auto Reverse

FC-O-A/B/C/D Control the flow of oxygen 0.5 0.3 0-2.40×104STD_m3/h Auto Reverse

PC-1 Control the outlet pressure 1.3 0.1 4800-6800kPa Auto Direct

PC-2 Control the downstream pressure 1.3 0.1 4800-6800kPa Auto Direct

LC Control the quench chamber level 10 30 0-100% Auto Direct

3. Dynamic Simulation of Online 3. Dynamic Simulation of Online Reset Process (ORP) operationReset Process (ORP) operation

The specific online reset process (ORP) is an ownprocess (ORP) is an own operation for the OMB CWS gasifier. C S gas e

A couple of shut-off burners will be put into operation under the high pressure when the other couple of burners arecouple of burners are still running.

ti t f th ORPti t f th ORP operation steps of the ORPoperation steps of the ORP

(1). Burner-C and burner-D are joined into the gasifier in 40th second. The setup (SP) value of CWS flow rate in burner-C and burner-D is set as 14.27 m3/h after 2 secondsm3/h after 2 seconds. (2). The SP value of the CWS and oxygen flow rate is separately set to increase 0.4 m3/h and 189 Nm3/h every 60 seconds. The SP value of CWS flow rate can be ordered to a desired point after 9 minutes Outlet pressure of the gasifier isbe ordered to a desired point after 9 minutes. Outlet pressure of the gasifier is adjusted automatically by the PC-1 and PC-2. During the process of syngas increasing, the SP value of PC-1 and PC-2 is set as 5300 kPa.(3) The SP value of gasifier pressure is set to increase 100 kPa every 60(3). The SP value of gasifier pressure is set to increase 100 kPa every 60 seconds. After the completion of the procedure, the SP value for the outlet pressure is 5800 kPa. During the pressure increasing, PC-2 will be set in manual and its valve opening is fixed The outlet pressure of gasifier will bemanual and its valve opening is fixed. The outlet pressure of gasifier will be regulated by PC-1. When the valve opening of the PC-1 is 0 percent, the PC-2 will be set in auto to conduct the gasifier pressure.

The dynamic simulation result of the ORP operationThe dynamic simulation result of the ORP operation

Coal water slurry pump-1(a) and -2(b)Coal water slurry pump 1(a) and 2(b)

Pressure control

Oxygen flow FC-O-A(a) and FC-O-C(b)

Pressure controlPC-1 (a) and PC-2 (b)

yg ( ) ( )

Response results of the inlet and outlet conditions in the ORP

4. Dynamic Simulation of 4. Dynamic Simulation of gasification temperature Controlgasification temperature Control

Gasification temperature control shemeGasification temperature control sheme

gasification temperature Control gasification temperature Control

Parameters of the PID controllersController Description Kc I(min) Arrange Type Action

FC-O-A/B/C/D Control the flow of oxygen 0.5 0.3 0-2.40×104STD_m3/h Cascade Reverse

O/C-A/B/C/D Control the oxygen-coal ratio 0.1 0.1 350-600Nm3/m3 Cascade Reverse

TC-A/B/C/D Control the outlet 0.1 0.1 600-1800℃ Auto ReverseTC A/B/C/D Control the outlet temperature

0.1 0.1 600 1800℃ Auto Reverse

Dynamic Simulation of Temperature Control with Dynamic Simulation of Temperature Control with CWS Concentration Disturbance CWS Concentration Disturbance

Coal water slurry

Temperature control

Oxygen-coal ration

Oxygen flow

5. Conclusions5. Conclusions

Based on the flow field analysis and the particle and gas RTD, a reactor Based on the flow field analysis and the particle and gas RTD, a reactor network model (RNM) of the OMB CWS gasifier with detailed reaction network model (RNM) of the OMB CWS gasifier with detailed reaction kinetics is established. The steadykinetics is established. The steady--state model is then transformed into the state model is then transformed into the d i d l hi h d t d i l tid i d l hi h d t d i l tidynamic model which adopts pressure driven solution.dynamic model which adopts pressure driven solution.

In the dynamic simulation of the ORP, the gasifier pressure will make a In the dynamic simulation of the ORP, the gasifier pressure will make a great effect on the operation conditions. With the gasifier pressure great effect on the operation conditions. With the gasifier pressure increasing during the ORP, the oxygen flow rate will be changed by the increasing during the ORP, the oxygen flow rate will be changed by the transformation of the pressure differential at both ends of the valve. The transformation of the pressure differential at both ends of the valve. The peak deviation of the temperature is about 33 peak deviation of the temperature is about 33 ℃℃ and that of the pressure is and that of the pressure is 106 kP106 kP106 kPa.106 kPa.

A temperature control strategy, which selects the oxygen flow rate as the A temperature control strategy, which selects the oxygen flow rate as the control object, is established to investigate the dynamic response for the control object, is established to investigate the dynamic response for the di t b f th CWS t ti Th lf l ti ti t th 1 5%di t b f th CWS t ti Th lf l ti ti t th 1 5%disturbance of the CWS concentration. The self regulation time to the 1.5% disturbance of the CWS concentration. The self regulation time to the 1.5% step changes for the CWS concentration is about 34 seconds in the OMB step changes for the CWS concentration is about 34 seconds in the OMB CWS gasifier. The peak deviation of the temperature is about 24CWS gasifier. The peak deviation of the temperature is about 24--26 26 ℃℃..

Future: Future: The dacay of the controllers and PID parameters studyThe dacay of the controllers and PID parameters studyy p yy p yThe validation of ORP operationThe validation of ORP operationThe dynamic simulation of other operation processThe dynamic simulation of other operation process

f ff fThe dynamic optimization of gasification system The dynamic optimization of gasification system

Challenge:Challenge:Challenge:Challenge:The dynamic model for the gasification systemThe dynamic model for the gasification systemThe gasifier temperature measurement and its decayThe gasifier temperature measurement and its decayg p yg p y

Email: chinadai@ecust.edu.cnWebsite: http://icct.ecust.edu.cn