Recent content by otised

The accuracy depends on the accuracy of the dp transmitter AND the primary flow element. If you want +/- 1% accuracy, you must start with a calibrated flow element. That gets you a certified calibration sheet for the flow element. It also costs you more.

I have comments on IGV control and SRV control. The comments apply to a properly tuned system with control devices calibrated to their specifications and with the hydraulic control oil pressure within specifications. Regarding IGVs: When the IGVs are operated in temperature control mode...

CSA, Overall, your cost estimates look reasonable. I will confirm that no Mark IVs were used for steam turbine control. The Mark IV was the first microprocessor based GE gas turbine control. At the time it was put into service, GE Steam Turbine was making their own control panels (not using...

Shahabas, You don't say anything about what type of gas turbine is driving the compressor. Is it a GE design or some other design? is it single shaft or 2 shaft? Is it heavy duty or aircraft derivative? What is the rpm it is being rotated at? Do you know for certain that it is reverse...

The instrument will operate and run properly. However, it will no longer be an intrinsically safe installation, it will not meet Ex requirements because in the event of a power supply failure there will be the capability of producing a spark with sufficient energy to ignite an explosive gas.

I don't know what your budget is, but back before I retired (over 9 years ago) our normal practice for boiler drum level measurement was to use differential pressure transmitters (with pressure compensation) for control and indication, with a code required independent measurement for indication...

GE supplies a fuel system that is designed for the heating value defined by the purchaser. They basically match the fuel nozzles to the specified gas. You would likely need to contact GE to see what changes (if any) are required to use your gas. It is possible control settings can be made to...

Abdullah, At 50 MW the IGV's are likely near the minimum angle and at 120 MW they are near or at maximum angle (you didn't identify which model gas turbine you have). Therefore the airflow through the gas turbine is significantly less at 50 MW. Also, at low IGV angle you may have inlet bleed...

From the information you have provided, I would suspect the problem to be in a solenoid that operates when L14HS (or L14HSX) picks up. You may be able to troubleshoot this when shut down. Compressor Bleed Valves would be one of the first things I would look at, but there are a lot of things that...

>As long as you have a properly calibrated temperature >sensor in the incoming steam, the amount of super-heat tells >you everything. ryanb clearly stated that the steam is saturated, so there is no superheat. I don't have any knowledge of a method of measuring the quality of saturated...

>we will try to adjust the IGV setting next week. My concern >is the mass flow reduction when we introduce more >restriction at IGV, temperature might increase, but how much >the reduction of mass flow has impact on the exhaust thermal >energy. Reducing the IGV angle will lower the air...

STLTLS, Warning on CTIM cable replacement: Make absolutely sure the sensors are thermocouples! Back before I retired, GE was using RTD's for these sensors. RTD's need copper interconnecting wires. They were typically 3-wire RTD's and all 3 wires must be used for accurate measurements.

Rokan, Do you have performance curves for both gas and HSD fuels? If so, do they indicate any difference in output between the 2 fuels? Where you are giving a difference in output between CC mode and SC mode, are you running CC mode with the exhaust gas passing through the HRSG and SC mode...

What is missing from this discussion is whether or not you need to measure the flow in these pipes. If you no longer need to measure the flow in these pipes, and won't need to in the future, then remove the orifice plates. If you do need to measure the flow, what means will you be using that...

I think the rated speed of rotation of the compressor has little to do with the need for VSV's. The purpose of VSV's and VIGV's is to prevent compressor stall (similar to surge on a centrifugal compressor). The rated speed of the gas turbine is a function of the diameter of the wheels. The air...