讨论下CFM56-7 的HPTACC/LPTACC/TBV

sust501 · 发表于 2011-6-21 22:28:48

讨论下CFM56-7 的HPTACC/LPTACC/TBV,有了解的吗？

davidyu · 发表于 2011-6-22 07:28:10

From 737-800 AMM part 1
The high pressure turbine active clearance control (HPTACC) system controls air from these two sources:
* HPC 9th stage bleed air
* HPC 4th stage bleed air.
The HPTACC valve mixes the air to control the thermal expansion of the HPT shroud support. Usually, the HPTACC system keeps the clearance between the HPT blade tips and the
HPT shroud support to a minimum. This increases the fuel efficiency. But when the engine internal temperature is not stable, or at high power conditions, the HPTACC system increases the turbine clearance. The HPTACC system increases the clearance to make sure that the HPT blades do not touch the shrouds.
The low pressure turbine active clearance control (LPTACC) system controls the low pressure turbine (LPT) blade tip clearance. The LPTACC increases or decreases the amount of
fan discharge air that goes to the LPT case. This air cools the LPT case. Cooling the LPT case controls thermal expansion which keeps the clearance with the LPT blade tips to a minimum. This increases fuel efficiency.
The transient bleed valve (TBV) system controls the quantity of the high pressure compressor (HPC) 9th stage bleed air that goes into the stage 1 low pressure turbine (LPT) nozzles. The TBV system increases the HPC stall margin during engine start and during engine acceleration.

边走边爱 · 发表于 2011-6-23 12:45:48

我简单的描述一下：

HPTACC ,LPTACC ,TBV .都是EEC控制，由伺服燃油作动。

HPTACC 是用的4级或者9级引气

LPTACC 是用风扇（外涵）空气

TBV是瞬时放气活门，直接将9级气体放到1级低压涡轮静子叶片

HPTACC和LPTACC 主要是发动机性能效率控制，TBV 是和VBV,VSV配合防喘。