Applied Engineering | Turbine Warming System Isaac Huerta
Turbine Warming System (TWS)
The Turbo generators may feature different operational problems:
• Continuous Stops/Starts
• Strong drop in the turbine temperature during shutdown
• Long starting time
• Control of Expansion Differences
• Generation of thermal stress and internal corrosion
In response, the Turbine Warming System, TWS, enables an improved performance and availability. It consists in placing on the turbine casing a set of thermal blankets to keep the turbine at set temperature from its stop to later start-up.
Reduction in start-up time and increase in turbine lifetime
A warm start-up can start plant production sooner than cold start-up. The turbine warming system (TWS) keeps the temperature of the component at a setpoint value to decrease the start-up time, therefore reducing the fuel cost and non-productive time, increasing in this way the plant’s profitability.
Expansion control of materials
Turbine Warming System (TWS):
• Controls differences in temperature between the upper and lower parts of the turbine casing.
• It makes the rotor warm up in proportion to the turbine casing, therefore reducing the start-up time and increasing the
• It averts potential damage due to misalignment when the valve temperature is kept uniform.
• It eliminates possible support structure repairs due to thermal stress problems.
Reduction of thermal stress
• Fatigue due to low cycles: the TWS system reduces the temperature gradients, minimizing the thermal stress levels and in this way increasing the amount of cycles the components can stand.
• Brittle fracture: the TWS system keeps the components over the fracture limit as it does not allow cooling too quickly.
Reduction in corrosion
The TWS system keeps the temperature of the turbine components over dew temperature, therefore preventing the generation of condensations, causing material corrosion.
Greater use of generated steam
With the Turbine Warming System the turbine will be operating sooner, so that the steam will be usable, in the case of the Solar Thermal power plants, averting the need to move the focus of the parabolic cylinder collectors and thus losing solar radiation.
Description of the Solution
It consists in a resistant heating element that is uniformly laid out on the hot side of an insulated blanket.
To control the system, thermocouples are installed on the turbine casing, which will monitor the start-up and shutdown of the various circuits of the thermal blankets.
It is a power distribution panel by areas that houses the main power transformers, switches, main contactors, as well as the individual area devices (output area contact, earth fault sensor and indicators).
The TWS system divides the turbine in different control areas. Each area can keep a set temperature within a +/-3ºC. These control systems enable accurately to control the unit through this control equipment: