8.8　Startup Boiler

8.8.1　For power plants that need to install startup boilers,the number,capacity,and fuel for the start-up boilers shall be determined by comprehensively taking into account the capacity,startup mode of units in conjunction with specific conditions of the region where the plants are situated,and shall comply with the following requirements:

1　The start-up boiler shall only have the capacity capable of supplying steam amount required by the thermal system of the first unit when starts up,without regard to the steam flow required by the main steam turbine to roll and commission and any margin.In regions where heating is required,necessary steam amount for heating purpose shall be included.The number and capacity of start-up boilers should meet the following requirements and in regions where heating is required,the upper limits should be taken:

1）For units rated at less than 300MW,1×10t/h-2×20t/h；

2）For units rated at 300MW,1×20t/h-2×20t/h；

3）For units rated at 600MW,1×35t/h-2×35t/h；

4）For units rated at 1000MW,1×50t/h-2×35t/h or 2×50t/h.

2　The start-up boilers should be designed as oil firing packaged boilers.In severe cold regions,the start-up boiler may be combined with the boiler supplying steam for construction and coal firing packaged boiler or conventional boiler should be adopted.

8.8.2　The steam parameters of startup boilers should be taken as those of low pressure boilers.The system should be simple,reliable,and its associated equipment should not be provided with standby.If necessary,the start-up boiler system may be designed in such a manner that allows easy dismantling and moving thereof later.

8.8.3　The coal-fired start-up boiler house should be designed as simply as possible；however,the requirements on safe production,environmental protection and labor safety shall be met..

8.8.4　The flue gas discharged from the start-up boiler house should be emitted through the nearest chimneys of boilers of generating units.In cases where independent chimneys must be provided for start-up boilers,they shall have a height up to the requirements as specified by the current national environmental protection standards.

8.8.5　For extended power plants,the auxiliary steam of the existing units shall be used as the start-up steam source,and no start-up boiler should be provided.