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Bob, There is a logic signal in the ST Mark VI that is true when the unit is on inlet pressure control. I believe it is called L83IPC. For GE supplied combined cycle controls, this is one of the signals that is used to turn off the temperature matching in the gas turbine control. The logic is...

9171E decoded: first character (9) is frame size next 2 characters, followed by sufficient number of zeros, is approximate rated horsepower last character (1) is number of shafts. So, this would be frame 9, 170,000 HP (126 MW), one shaft (HP rotor only). Most of the frame 9's (E's...

I had similar thoughts to CSA, regarding availability of Mark V. Regardless, a simplex Mark V (or Mark VI), if properly configured, should be more reliable than a Mark I (or Mark II) control. While it will be less reliable (I am talking about running reliability here) than a TMR control, it...

The "quick and simple" way to stop the trips is to put a time delay on them to filter the short duration spikes. If the spike lasts only milliseconds, use a 1 second time delay. You may need approval from the turbine supplier, but RTD's have a time lag anyway, and temperatures don't usually...

Until temperature matching sequence is complete you will not be able to go to preselected load. Temperature matching usually has 2 parts. First part warms up the HRSG, if it had been depressurized. This typically holds GT exhaust temperature to 371 degC. Second part matches the exhaust...

Assuming the GT is running at or near rated speed, about the only way for the temperature to actually increase is via inlet air heating. If your machine does not have inlet air heating, I would suspect the accuracy of either or both temperature measurements, since there should be a drop in...

The meaning (generally speaking) is that a differential pressure flow measurement (primary flow element is orifice, flow nozzle or venturi) is compensated for temperature and pressure, to adjust for the change in density of the fluid with temperature and pressure. For liquids, temperature...

Another possibility to consider is the waste heat recovery boilers. What is the exhaust back pressure at the GT Exhaust (or boiler inlet) of the 3 units? I don't know if you have pressure transmitters on the GT exhaust - if so, signal name may be P96EP or something similar. Higher back pressure...

You did not say anything about the relative sizes of the 2 valves, or why 2 valves are required. I am guessing here, that valve A cannot handle the maximum flow condition and so valve B was added to meet this flow requirement. Perhaps the high flow condition does not occur very often and would...

If the mass flow has already been compensated for pressure and temperature (which is really density compensation), and you know the density or specific volume, you divide the compensated mass flow by density (or multiply by specific volume) to get actual volumetric flow.

Divide the mass flow by the density of the fluid (or multiply by the specific volume) to convert it to volumetric flow.

If you know the density (specific gravity) or specific volume of the fluid, you can convert between mass flow and volumetric flow.

The former "Projects" group does still exist in GE. It currently goes by the name "Global Power Plant Systems Department" (or at least that is what it was called as of the time I retired last November). It is headquartered in Schenectady, with satellite operations in Atlanta (Norcross), GA, and...

Water induction is a horror story, and is the primary reason for tripping on high drum level. I believe that ASME code requires this protection. For calculating saturation temperature as a function of pressure, most DCS controls used in power plants these days have that as a built in steam...

In multishaft CCPP projects I have been associated with, the usual practice was to have 3 distinct high drum level settings: H = alarm only HH = trip HRSG and close its isolation valve to stop steam flow to the header. After time delay, if isolation valve is not closed and the drum level...

Hibrahim, I received your e-mail with attachments. I sent back the SRV schematic with comments. Looking at your earlier notes, if you were able to set the SSVD card per the control specification it should have worked properly. The pressure setpoint is called the P2 OR PRESSURE CONTROL VOLTAGE...

You don’t say whether this is a new problem or not. Has the plant been upgraded or changed so the LP Steam is now greater than the original design? Or has this been a problem from the beginning? First, dig out your flow element calibration sheet. It will tell you the design point of the flow...

So why are you trying to run this machine with broken/missing airfoils? By the way, if the "blades" are on the turbine wheel, they are more properly called "buckets." "Blades" are on the compressor wheels.

I am running out of ideas here. It's just been too long since I have dealt with the Mark II controls, and I don't remember what cards did what. I still think the problem is in the setpoint circuit, because it appears that the valve is controlling to the 18 bar pressure. Without the elementary...

You made a common conversion mistake when dealing with temperature differentials. You likely converted TTXSPL5 of 30 degF to -1.1 degC. If you just multiply 30 by 5/9 you get 16.7 degC, which will give you the 62 degC result your were expecting. DO NOT USE THE 32 degF OFFSET WHEN CONVERTING...