Overspeed protection device of turbine

Abstract

The invention discloses an overspeed protection device of a turbine. The turbine comprises a stop electromagnetic valve, a stop electromagnetic valve power supply circuit and a speed measuring gear. The overspeed protection device of the turbine comprises two sets of same electronic overspeed protection devices and an OR gate, wherein the input end of the OR gate is connected with the output endsof the two electronic overspeed protection devices respectively, and the output end of the OR gate is connected with the stop electromagnetic valve power supply circuit, wherein each electronic overspeed protection device comprises three measuring channels and a two-in-three overspeed protector for receiving the output signals of the three measuring channels; each measuring channel comprises a speed measuring probe, rotation speed modules and a relay which are connected sequentially and mounted on the speed measuring gear; and the input end of any rotation speed module in the same electronic protection device is connected with the input ends of the other two rotation speed modules. In the invention, by adopting the electronic devices, the action is reliable, and the rotation speed of the machine set does not need to be increased to the action rotation speed in the testing process, thus the safe operation is guaranteed, the cost is saved, the turbine is protected, and the system is simpler.

Description

technical field [0001] The invention relates to the field of steam turbines, in particular to a steam turbine overspeed protection device. Background technique [0002] The steam turbine generator set is a high-speed rotating machine, and its rated speed is generally 3000r / min. Once speeding occurs, significant property and personnel losses will occur. The traditional method of steam turbine overspeed protection system is to install a mechanical emergency breaker on the small shaft of the steam turbine. After the unit is overspeeded, the eccentric flyweight acts under the action of centrifugal force to drain the safety oil and stop the unit. It adopts a mechanical emergency breaker and an electronic overspeed device to achieve the purpose of overspeed protection. Due to the use of a mechanical emergency breaker, the mechanical wear and tear will cause its action speed to be inaccurate. On the other hand, its setting value depends on adjusting the tension of the spring, so...

AI Technical Summary

Problems solved by technology

In addition, due to the problem of jamming and refusal to move mechanical parts, it affects the safety of the unit

This is not economical (such as the need to restart the steam turbine unit for each adjustment, and it will cost hundreds of thousands of yuan to conduct a test), and at the same time, the overspeed test will affect the service life of the steam turbine rotor because the unit will be overspeeded to more than 3000r / min

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