K
Hi all,
We have 2 GE Frame 9E gas turbines at our facility. The design base load is 115 MW & ambient temperature of 28 degree Celsius and a Mark 5 control system. We have a 17 stage axial compressor, 14 canister type combustion chamber & a 3 stage turbine. Design turbine inlet temperature is 1124 degree Celsius. The first 2 stages of turbine buckets has internal air passages for cooling while the third stage does not.
While checking the passages for cooling air arrangement, I was unable to find any provision for cooling the second stage shrouds. The first stage shrouds, first & second stage nozzles have cooling air from the compressor discharge air while for third stage shrouds, a separate extraction line from compressor 8th stage is available. However, there is seemingly no provision for cooling either third stage nozzles or second stage shrouds. The third stage nozzles have a hollow design, which seemingly suggests an air passage but it does not have any corresponding holes on turbine shell. Is this due to some other design consideration? And second stage shrouds being uncooled is even more baffling since they encounter higher temperatures compared to third stage shrouds, which are cooled. What is the reason for this design or is there some other cooling arrangement which I have been unable to identify?
We have 2 GE Frame 9E gas turbines at our facility. The design base load is 115 MW & ambient temperature of 28 degree Celsius and a Mark 5 control system. We have a 17 stage axial compressor, 14 canister type combustion chamber & a 3 stage turbine. Design turbine inlet temperature is 1124 degree Celsius. The first 2 stages of turbine buckets has internal air passages for cooling while the third stage does not.
While checking the passages for cooling air arrangement, I was unable to find any provision for cooling the second stage shrouds. The first stage shrouds, first & second stage nozzles have cooling air from the compressor discharge air while for third stage shrouds, a separate extraction line from compressor 8th stage is available. However, there is seemingly no provision for cooling either third stage nozzles or second stage shrouds. The third stage nozzles have a hollow design, which seemingly suggests an air passage but it does not have any corresponding holes on turbine shell. Is this due to some other design consideration? And second stage shrouds being uncooled is even more baffling since they encounter higher temperatures compared to third stage shrouds, which are cooled. What is the reason for this design or is there some other cooling arrangement which I have been unable to identify?
