Table of Contents
What is exhaust spread in gas turbine?
An exhaust temperature spread refers to a high differential in temperature readings between the thermocouples placed radially around the exhaust of a gas turbine. Spread indicates the difference between maximum and minimum temperatures recorded by exhaust temperature thermocouples.
How do you calculate gas turbine spread?
First spread is the difference between the first maximum thermocouple reading and the least value thermocouple reading. Second, second highest thermocouple minus the second lowest value reading. Same applies to the third spread.
What the thermocouples does in turbine engines?
Thermocouples combine two unlike metals that cause current flow when heated. [click image to enlarge] Thermocouples are used to measure high temperatures. Two common applications are the measurement of cylinder head temperature (CHT) in reciprocating engines and exhaust gas temperature (EGT) in turbine engines.
What is gas turbine blade path temperature?
The highest temperature in the gas turbine cycle occurs at the exit of the combustion chamber and it is limited by the maximum temperature that the turbine blades can withstand. The design conditions are up to 1500K and 10 bars for total temperature and total pressure, respectively.
What do thermocouples do?
Thermocouples are sensors used to measure temperature. A thermocouple consists of two wires, or wire legs, made from different metals. The legs are welded together at one end, into a junction, where the temperature is measured. A voltage is created when the junction senses a change in temperature.
Which types of thermocouples are used in pure jet engines exhaust?
Abstract: The main measurement methods used for the determination of exhaust gas temperatures include resistance temperature sensors and thermocouples. Resistive sensors commonly used for engine exhaust gas applications include platinum resistance sensors, such as Pt200, and NTC thermistors.
What is exhaust gas system?
An exhaust system is used to guide reaction exhaust gases away from a controlled combustion inside an engine or stove. The entire system conveys burnt gases from the engine and includes one or more exhaust pipes. Cylinder head and exhaust manifold. A turbocharger to increase engine power.
What is Blade Path spread?
Blade Path Spread is the difference between the average blade path temperature and the high blade path temperature. During startup, there are different set points for alarm and trip based on the speed of the gas turbine. Once you’ve reached rated speed the set points for alarm, unload, or trip are no longer variable.
What is the basic configuration of a gas turbine cycle?
In this schematic, a basic configuration of a gas turbine cycle (GTC) is considered. The discharged hot exhaust has a relatively large flow rate and is directed to the steam generator, which is mainly a HEX and helps to recover a part of the waste heat.
Why are GE gas turbine exhaust systems getting stronger?
Since their introduction in 1978, advances in materials, cooling, and design have allowed GE gas turbines to operate with increased firing temperatures and airflows. These advances have resulted in elevated exhaust temperatures and increased aero loading that affect the strength of exhaust systems during turbine startup, operation, and shut down.
Why does the exergetic heat-recovery performance of a gas turbine improve?
In these cases, the exergetic heat-recovery performance improves because the additional steam generation at lower pressure allows a stepwise approximation of the cooling gas turbine exhaust temperature versus heat transferred profile. This results in lower heat transfer exergy destruction downstream of the high-pressure (HP) evaporator.
Can high temperature exhaust gas be used in a Brayton cycle?
The high-temperature and low-pressure exhaust gas still have great potential, and can be utilized by the integration of the WHR subsystems to the Brayton cycle. The high energy can be partially used again if the expelled gases can be used in a Rankine cycle [1].