6.8　Maintenance

6.8.1　The assembly and maintenance area for steam turbine shall meet the following requirements:

1　The maintenance area in turbine house should be sufficient to meet the requirement for maintaining the turbo-generator set..

2　If the operating floor of turbine house is designed to be a monolithic platform,every two units should be provided with one maintenance area at ground level which is sized to meet the requirements for lifting large components and overturning turbine casings.

3　If the steam turbine is arranged in island mode,every two to four units should be provided with one maintenance area at ground level,and the assembly area should be arranged together with the maintenance area and in consideration of access of equipment into the turbine house.

6.8.2　The overhead cranes inside the turbine house shall be arranged in accordance with the following requirements:

1　Two overhead cranes with the same lifting capacity may be installed for four and more 125-200 MW units,or for two and more 300MW and above units.

2　The lifting capacity of overhead cranes shall be selected according to the heaviest component needed to be lifted for maintenance（expect for the generator stator）.

3　The overhead cranes may be reinforced to satisfy the need for lifting generator stator depending upon the specific conditions of the project through techno-economic comparison.

4　The installation elevation of overhead cranes shall be determined based on the maximum lifting height of the lifted equipment.

6.8.3　The lifting facilities used for maintenance in the main power house area shall be provided in accordance with the requirements below.

1　Lifting facilities shall be provided for those equipment,pipe fittings and valves with lift load of one ton or above.

2　The equipment that has a lifting load of three tons and above and is used frequently should be provided with motor-driven lifting facilities.

3　Motor-driven lifting facilities shall be provided for those equipment with lifting load of 10 tons or above..

4　In the main power house,mobile lifting platform may be provided at locations where it is impractical to provide stationary maintenance and maintenance platform.

5　The outdoor equipment may be provided with movable or stationary lifting facilities depending upon the surrounding conditions.

6.8.4　The lifting holes and the corresponding lifting facilities in the main power house shall be provided in accordance with the following requirements:

1　In boiler house,motor-driven lifting facilities and corresponding lifting holes shall be provided with a capacity of 1 to 3 tons to lift components from ground level to the highest platform..

2　At both sides of the coal bunker bay there shall be provided with lifting holes from the bottom floor to the belt floor of the bunker bay,and lifting facility shall be provided.

3　In other areas where it is necessary to maintenance and replace equipment which cannot be lifted with the bridge crane in turbine house or the lifting facilities mentioned in Sub-clauses 1 and 2 of this clause,additional lifting holes and lifting facilities shall be provided appropriately.

6.8.5　The various main and auxiliary equipment in main power house shall be provided with necessary maintenance space,laydown area,transportation access as well as operation,and maintenance accesses.The longitudinal transportation access at the bottom floor of the main power house should be through the main power house,with entrances provided at both terminals.There shall be provided with entrances at Row A column side at 0m level of the maintenance area of the turbine house which lead to the plant roads.

6.8.6　The quantity of elevators and their arrangement shall conform to the following requirements:

1　For 125MW units,every two boilers should be provided with one elevator.

2　For units rated 200MW and above,each boiler should be provided with one elevator.

3　The elevators should serve both cargo and passengers with the loading capacity of 1 to 2 tons.Their traveling speed shall be determined to ensure that it takes no more than 60 seconds for them to travel from bottom floor to top floor,and should not be less than 1m/s.

4　The elevators should be arranged between the central control room and boiler,close to the front end of boiler,and stop stations should be provided at various main platform floors of the boiler proper.

5　Additional elevators may be installed in other production buildings as required by operation and maintenance.

6.8.7　Main valves,dampers and actuators shall be arranged for easy operation and maintenance.Operation and maintenance platforms shall be provided if necessary.