Calculate Gas Consumption Per Hour


Thread Starter


Dear Friends,
We will start our turbine by gas and I want know the gas consumption of turbine per hour if the GE gas Turbine Frame 5 max power 18 mg and the fuel consumption 6830kglh. Please tell me how to calculate the gas consumption and power consumption.

If GE was the supplier of the control system, there is usually a document titled 'Control Specification' provided with the turbine (older turbines sometimes had three sections of the 'Control Specification' while newer units (including control system upgrades) usually only have a single 'Control Specification). The 'Control Specification contains a lot of really useful information, and the Fuel Control Section is usually section 05, with Section 05.01 for liquid fuel, and Section 05.02 for gas fuel.

Each fuel section of the Control Specification usually has a section titled 'Expected Fuel Characteristics' which lists the UHV, LHV, Methane, etc., constituents of the fuel that was expected to be burned in the turbine. There was also a table showing expected fuel flow-rates for Firing, FSNL, 25%-, 50%-, 75%- and 100% load--in lb/sec or kg/sec, which you should be able to convert for your purposes.

The units you provided seem strange; I'm not familiar with them.

Also, somewhere in the unit instruction manuals provided with the unit and auxiliaries you should be able to find a section which has the performance guarantee information, as well as the performance correction curve(s). One of the performance guarantee documents should, if nothing else, give you the heat rate for the turbine at rated power output, which, if you know the heat content of the fuel you are burning should be useful in calculating expected fuel consumption.

Most simple-cycle GE-design heavy duty gas turbines are about 30-35% efficient in converting hydrocarbon energy into electrical energy. So, you may also be able to roughly estimate expected fuel flow if you know the energy content of the fuel to be burned.

As for calculating power consumption, I presume you are talking about the auxiliary loads powered by the gas turbine which are often subtracted from the gross power output to achieve the net power output. Well, the auxiliary power consumption is a function of the plant design, and can vary from plant to plant depending on configuration of the unit and the auxiliary power transformers supplying power to the auxiliary loads (pumps; fans; lights; etc.). Sometimes (often, usually) there is an Auxiliary Power Meter on the Generator Control Panel which has CTs which only look at auxiliary power consumed by the turbine auxiliaries.

To estimate the auxiliary power consumption you would have to review the plant one-line diagrams and make some calculations based on expected loads based on the plant design. This isn't an easy calculation, again--because it's based on plant design and configuration.

Hope this helps! Perhaps someone with a similarly-rated Frame 5 can write back with more helpful information.