NTPC O&M CONFERENCE FEB 13-15, PDF Free Download

NTPC O&M CONFERENCE FEB 13-15, 2013 APPLICATION OF COMPUTATIONAL FLUID DYNAMICS IN IMPROVING POWER PLANTS PROCESSES-CASE STUDIES NETRA, CenPEEP, TANDA & KORBA presented by KUMAR SWADHIN, V.K.DIXIT

APPLICATION OF COMPUTATIONAL FLUID DYNAMICS IN IMPROVING POWER PLANTS PROCESSES-CASE STUDIES INTRODUCTION CASE STUDY 1: TANDA FLUE GAS DUCT 3D MODELING SITE MEASUREMENTS VALIDATION OF MODEL COMPARISON WITH EXISTING DUCT EFFECT OF BRACINGS & DAMPERS IMPLEMENTATION BENEFITS CASE STUDY 2: KORBA FLUE GAS DUCT 3D MODELING & ANALYSIS COMPARISON WITH EXISTING DUCT IMPLEMENTATION BENEFITS WAY FORWARD

INTRODUCTION OBJECTIVES Reduction In Pressure Drop Flow Uniformisation: Reduction In Erosion Id Fan Power /Current Reduction To Increase Flue Gas Flow To PAPH (In Case Of Korba) TEAM WORK NETRA, CenPEEP, TANDA: BMD/EEMG NETRA, CenPEEP, KORBA : BMD/EEMG 3

TANDA FLUE GAS DUCT MODIFICATION CASE STUDY 1 FLUE GAS DUCT SECTIONS STUDIED APH Outlet to ESP Inlet ESP Outlet to ID Fan Inlet ID Fan Outlet to Chimney Inlet

DEVELOPMENT OF 3-D DOMAIN & MESHING IMPOSITION OF BOUNDARY CONDITION AND CASE SET-UP

SITE MEASUREMENTS FOR BOUNDARY CONDITIONS SL.NO PARAMETER UNIT AVERAGE MEASURED VALUE (28.03.2012) 1 FLUE GAS FLOW, APH-ESP SECTION TPH 930 2 FLUE GAS DENSITY, APH-ESP SECTION Kg/m3 0.8347 3 FLUE GAS FLOW, ESP-ID SECTION TPH 1004 4 FLUE GAS DENSITY, ESP-ID SECTION Kg/m3 0.864 5 FLUE GAS FLOW, ID-CHIMNEY SECTION TPH 1004 6 FLUE GAS DENSITY, ID-CHIMNEY SECTION Kg/m3 0.8997 7 FLUE GAS VISCOSITY Kg/m-s 2.2 10-5 8 PRESSURE Pa As Measured Mathematical Model: Standard k-ɛ with Standard wall functions 7

VALIDATION OF CFD MODEL CHIMNEY APH A P Measured: 54.8 CFD: 52.0 Error %: -5.1 ESP A P Measured: 74.7 CFD: 69.94 Error %: -6.37 ID A P Measured: 68.01 CFD: 68.9 Error %: 1.31 ID B P APH B Measured: 56.4 CFD: 52.0 Error %: -7.1 P ESP B ALL VALUES OF PRESSURES ARE IN mmwc P Measured: 55.7 CFD: 54.47 Error %: -2.2 ID C Measured: 71.1 CFD: 72.56 Error%: 2.05

MODEL RESULTS COMPARISON OF VELOCITY CONTOURS APH-ESP 9

MODEL RESULTS COMPARISON OF PARTICLE TRACKS APH-ESP BASE MOD BASE MOD

MODEL RESULTS COMPARISON OF VELOCITY CONTOURS ESP-ID

MODEL RESULTS COMPARISON OF VELOCITY CONTOURS ID-CHIMNEY MOD 12

MODEL RESULTS COMPARISON OF VELOCITY CONTOURS ID-CHIMNEY MOD 13

BRACINGS V-TYPE V-TYPE MODEL RESULTS EFFECT OF BRACINGS AND DAMPERS SECTION p with no bracings mmwc p with bracings mmwc % Difference DIAGONAL DIAMOND APH-ESP 34 52 53 ESP-ID 63.5 69.9 10 DAMPER SECTION p Across Damper mmwc DAMPER 1 (ESP O/L) 7 DAMPER 2 (ID I/L) 9 This can be used to explore optimization of number of braces without sacrificing structural integrity

MODIFICATION DRAWING DEVELOPMENT & IMPLEMENTATION

ACTUAL SITE RESULTS REDUCTION IN PRESSURE DROP Date Section Fan Combination CFD Prediction for original duct Measured in Modified duct ΔP Gain ΔP mmwc ΔP mmwc ΔP mmwc 11.12.12 Total A&B 313.8 235.1 78.7 12.12.12 Total A&C 302.0 237.2 64.8

ACTUAL SITE RESULTS FLOW UNIFORMISATION Before Modification 28.03.12 ID A&C Left Right Left Right View direction ESP I/L A ESP B I/L B After Modification 12.12.12 ID A&C Left Right Left Right The flow pattern indicates uniformization of flow post modification; this will result in reduced erosion of duct.

ACTUAL SITE RESULTS FLOW UNIFORMISATION SITE MEASUREMENTS VIDEO CLIPS U2-11 DEC 2012-ID B INLET FLOW U2-12 DEC 2012-ID A INLET FLOW

CONCLUSION MODIFICATION RESULTS Total Pressure Drop Reduction by ~ 60 mmwc Corresponding ID Fan Power Reduction by ~ 50 kw in each ID Fan ( ~ 5 Amp in each ID Fan) Flow Uniformisation in Duct Will result in Reduced Erosion in Duct

KORBA FLUE GAS DUCT MODIFICATION CASE STUDY 2 FLUE GAS DUCT SECTIONS STUDIED ECO O/L APH I/L

KORBA UNIT#6 (500 MW e ) Problem of Low PAPH outlet temperature Attributable to less flow of flue gas to PAPH SIMULATION DOMAIN: ECO OUTLET-TO-APH INLET Duct Geometry used for CFD Simulation, Eco outlet A to PAPH/SAPH inlet

VELOCITY CONTOURS AT VARIOUS SECTIONS: BASE KORBA 500 MW FG DUCT ECO O/L APH I/L TOP VIEW A B C ZONE 3 FRONT VIEW SIDE VIEW FRONT VIEW midplanes E ZONE 1 E ZONE 2 ZONE 3 F G F G TOP VIEW midplane SIDE VIEW midplanes Velocity profile at different cross section of Flue gas duct

COMPARISON VELOCITY CONTUORS AT HORIZONTAL MID PLANE KORBA 500 MW FG DUCT ECO O/L APH I/L Before HORIZONTAL MID-PLANE After

IMPLEMENTATION OF MODIFICATION Sketch of modification implemented and photographs of the modifications being implemented.

CONCLUSION MODIFICATION RESULTS Data Collected With Site EEMG on 02.06.2012 Data Analysis Concluded an Improvement of 4-5 C in PAPH Outlet Temperature.

WAY FORWARD REPLICATION OF SIMILAR WORK Potential for pressure drop reduction in FG ducts is largely untapped, especially in ID Fan to Chimney section PROCESS IMPROVEMENT IN OTHER AREAS CW Pump Sump Study Application of Boiler Combustion Modeling OPTIMIZATION OF NUMBER OF BRACINGS Initiation of Study on Optimization of number of support braces without sacrificing the structural integrity

RESULTS ID FAN CURRENT REDUCTION Unit Date Overall Leakage ID Fan Current Average % Amp 4 26.04.2010 28 70 2 26.12.2012 46 73.5 2 Projected 28 64 U#2 ID Fan current are comparable Despite high leakage. If U#2 leakages are brought down to U#4 level, the ID Fan current will come down to 64 Amp as against 70 Amp in case of U#4. This 6 Amp Gain is reflection of contribution of guide vanes.