TERBINE DRIVEN BOILER FEED PUMP WORK OPTIMIZATION · PDF fileTERBINE DRIVEN BOILER FEED PUMP WORK OPTIMIZATION ... Fig.2 Turbine Driven Boiler Feed Pump ... 8th Feed Water Heater before

TERBINE DRIVEN BOILER FEED PUMP WORK OPTIMIZATION

By Mr. Tuangsit Prajaksab, Technician Level 4, Maintenance Division, Bangpakong Power Plant, Electricity Generating Authority of Thailand, Chachoengsao, 24130, Thailand.

Mobile : +66859675958 Email : [email protected]

[Overview]

Bangpakong Power Plant has 3730 MW productivity including 4 Thermal Power Plants (Fig.1) and 3 Combined Cycle Power Plants. Most of electricity produced has been distributed to Bangkok and perimeter provinces, other would be distributed to Eastern zone including Chonburi, Rayong, Chantaburi and Trad. Bangpakong.

Fig.1 Bangpakong Thermal Power Plant 1-4 Unit

[Introduction]

Each 2 years or 16,000 equivalent hours, Thermal Power Plant in Bangpakong Power Plant has to be shut down to be repaired on Planned Outage Maintenance on Minor inspection. Bangpakong Thermal Power Plant Unit 1 had to be shut down during 30th Jan – 24th Feb 2016, Turbine Driven Boiler Feed Pump (TD-BFP) is one of CPM (Critical Path Management) that “Turbine Maintenance Department” responsible.

Fig.2 Turbine Driven Boiler Feed Pump (TD-BFP) and other nearby equipment

TD-BFP responsible is stepping up the pressure from LP system to HP system passing through 6th, 7th, 8th Feed Water Heater before entering to boiler. The power operated pump is steam, trapping from HP Steam Turbine that much more saver than using motor driven. TD-BFP is start operated at 15% load or 80 MW up to full load at 550 MW.

Fig.3 Thermal Power Plant Diagram

[Method]

Before using Optimizetion method, the parties must be set, Turbine Maintenance Department and Maintenance Engineering Department were selected. Starting meeting between “Turbine Maintenance Department” and “Maintenance Engineering Department” to aim, understand the goal of the process optimization and share the work each department will be doing after meeting.

Fig.4 Meeting between Maintenance Engineering Department & Turbine Maintenance including Training

Maintenance Engineering Department was assigned to gather the engineering information including vibration and other statistics needed of TD-BFP. The data were analyzed and studied the possible to optimizetion in equipment TD-BFP. The vibration history 10 bearings 3 years early found good limit (0-2.9 mm/s)

Fig.5 Data of vibration at various times before analyzed

Turbine Maintenance Department was assigned to collect data analyzed of the Maintenance Engineering Department including the CPM of TD-BFP, starting analysis the activity within TD-BFP should do. The activity shown that HP Stop Valve. HP Governing Valve. LP Stop Valve. LP Governing. LP Stop Valve Actuator. and LP Governing Valve Actuator must be removed and inspected because there were no sensor to be monitored. It was possible that that crack on valve may be found after using for 1-2 years. Turbine Maintenance Department checks all times to prevent those possible. From the sign of vibration that Maintenance Engineering analyzed shown that almost vibration was in good limit or less other was in acceptable limit that possible be a human error while collecting data. Moreover the trend of each vibration at each bearing shown that won’t be over the admissible limit (2.9 – 7.3 mm/s). So there is no need to be overhaul all bearings, that can be saved time, Man-hour and maintenance cost.

Fig.6 Schedule of Turbine Maintenance CPM

Fig.7

Fig.8

Fig.9

Fig.7,8,9 Graph shown between vibration and date at various time after Planned Outage MI BPK-T1 (2013)

[Result]

After all analysis and statistic gathering, the result can be shown us that there is no need to overhaul all bearings mentioned. Moreover, Available Man – hour can be shifted to do other work such as the Booster Pump & Lube oil Cooler. Oil Collection Tank. LP Stop Valve Actuator and LP Governing Valve Actuator to be earlier and quicker as shown on fig.XX

Fig.10 Schedule after work optimization and shifted man-hour

Other result can be category as

1. Working job reduction : 5 jobs including Bearing 1,2, Thrust Bearing, Bearing main pump & reducing gear, Bearing booster pump & reducing gear.

2. Money spent on man-hour, spare part and salary can be saved 6,327,720 Baht (refer to Fig.10)

3. Times can be reduced 10 days

[Conclusion]

Optimization must have enough factors to be considered. The scope of work can be specified by equipment’s condition that will be the direct impact to cost and POMD. This optimization is the vision of the Electricity Generating Authority of Thailand’s governor.

In the future, this project will be supported due to the Governor’s vision and will be done on next planned outage project to save more cost and gain more availability to EGAT and Thailand.

[Reference]

1. Thermal Plant Unit1-4 Operating Data from Thermal Plant Planning Section

2. Turbine Steam Path Volume1 Maintenance& Repair, William P.Sanders. P.Eng.

3. Thermal Plant Unit-3 and 4 Management Report from Headquarter Mechanical Planning Section.

4. Maintenance Engineering Department for data collecting and cooperation.

5. Mechanical Maintenance Bangpakong Power Plant for cooperation and provide data.