Temperature Control System Gas Turbine

Temperature Control System Gas Turbine Points : Temperature Control System Gas Turbine Power Plant To operate within design thermal stress limitation of turbine parts, there are maximum allowable temperature which cannot be exceeded. Thus, a temperature control system is required to hold fuel flow to the gas turbine when operating temperature reaches design limits. Within the gas turbine, the high’s temperature is attained in the combustion chamber and the same gas temperature which must be limited by the control system. Since it is impractical to measure temperature in the combustion chamber or at the turbine inlet directly, the temperature control system is designed to measure and control turbine exhaust temperature — referred to as firing temperature is made as possible through non turbine performance relationship, however, the exhaust temperature valve alone does not fully determine firing temperature level. Another dependent parameter is required to define the prevailing firing temperature.
For a giving firing temperature, a gas turbine is capable of generating more power on cold days. This is because with cold air the gas turbine compressor greater mass flow and produces an increase pressure ratio compressor discharge pressure (feed) can be used to measure pressure ratio as a reasonable simplification because barometric pressure variation is small. Knowing exhaust temperature, the Firing temperature can be accurately determined using ped as a parameter, From thermodynamic relationships, gas turbine cycle performance calculations, and know site conditions operating points can be graphically plotted as compression discharge, pressure, ped, versus exhaust temperature. When points of content, tiring temperature are connected, the result is a temperature control “curve”. Linear zed for hardware simplicity. An isothermal control line is imposed on the constant (limiting) Firing temperature line-to protect against exceeding the gas turbine exhaust system design temperatures.
The gas turbine temperature control system acts to control fuel flow-through VCE command when the limiting firing temperature is reached. The system determines. The limiting Firing temperature by a present relation ship of two measured parameters ; exhaust temperature (TX) and compressor discharge pressure (ped) The temperature sensors consists of twelve chromel Alumel thermocouples located around the turbine plenum.
The twelve thermocouple signals are transmitted through individual pairs of thermocouple wires that connect to the averaging module in the SPEED TRONIC panel. A switch is provided for each thermocouple, to disconnect it from the circuit, or to bring it to the check output. Reject And Check Positions of the switch arc used for these purpose. For normal operation. All switches should be in the normal position. The averaging module performs two major functions that are directly related to the purpose of temperature control.