SU560071A1 - Turbine automatic start device - Google Patents

Description

This invention relates to the automation of steam turbines of thermal and nuclear power plants.

1-1, devices for automatic start-up of a turbine are known, which contain a loading controller with metal temperature and turbine load sensors, which control the heating of the turbine during start-up according to a closed thermal state control circuit, where the temperature differences in the turbine metal limiting its loading rate.

If these temperature differences are precisely maintained at the maximum permissible level, the starting process will be optimal. However, due to the differentiating properties of the control object, such devices have a certain static control error. In addition, additional deviations from the optimal process inevitably arise due to errors in the measurement of the temperature near the heated surface and the extrapolation of the temperature distribution in the controlled structural elements of the turbine to the heated surface. A disadvantage of such devices is also the difficulty of adjusting them due to the variable dynamic properties of the load control loop-adjustable temperature difference.

It is also known a device for automatic launch by steam of omscalp parameters containing a loading controller with metal temperature and turbine load sensors, an adder and a non-linear converter that implements a piecewise linear dependence of the load on the current temperature of the metal of the turbine at a characteristic point.

This device is the closest to this technical essence and the achieved result.

However, the change in the temperature process of the temperature difference between steam p of the metal of the turbine and the heat transfer coefficient from steam to metal is taken into account by a very roughly discrete change in the slope of the static characteristic of the regulator loaded with its initial load unit and corrector. As a result, implemented processes and processes can differ markedly from the optimal ones.

The aim of the invention is to improve the accuracy of the start-up process.

This is achieved by the fact that the output of the load sensor through the non-linear transducer is connected to the cyMNsaTopa input together with the metal temperature sensor, and the output of the adder via the second linear converter connects to the regulator input.

FIG. I shows a diagram of the device for the case of monitoring the temperature of the metal of the turbine at one characteristic point; in fig. 2 - the same for the case of several indicators used in the temperature state of the turbine.

The device for automatic start-up of the turbine 1 contains (see Fig. 1) a loading controller 2 with a metal temperature sensor 3 and a turbine load sensor 4, an adder 5, whose input is connected with 3 metal temperatures and through a non-linear converter 6 with a turbine load 4 and the output is via the second nonlinear converter 7 with the regulator 2 loading the load. The loading of the turbium with the launch of constant parameters is performed by the regulator 2, which is feedback connected to the load sensor, by acting on the control valves on the steam supply to the turbine 1. The pressure sensor behind the control valves or in the hydrotope part of the turbine. The conversion of the signal from the sensor 4 to the load in the nonlinear transducer 6 reflects the change in heat transfer conditions from steam to metal during the start-up process, as well as the change in the maximum allowable value of the limiter, which limits the start-up speed, from the turbine's operating mode. Connecting the input of the nonlinear converter 6 to the metal temperature sensor 3 makes it possible to take into account the originality of this well also from the metal temperature. As the metal temperature sensor 3, a calculating device can be used that simulates the heating of an element of a turbine design that limits the speed of the start, for example, a rotor. Conversion of the signal at the output of the adder 5 in the non-linear converter

7 corresponds to the nonlinear dependence of the change in steam temperature in the turbine on the pressure pipe.

If the turbine start-up speed is limited by more than one indicator of its temperature state (Fig. 2), two or more sensors 3, 8, etc. are installed at the turbine at characteristic points, each connected to the input of the corresponding adder 5, 9 and so on, in parallel with the output of nonlinear converters 6, 10 of the signal from load sensor 4, and the signals with output of adders 5, 9, etc. after nonlinear conversion in converters

7, 11 are iodized to a minimum allocation unit 12, the output of which is connected to the input of controller 2.

Thus, this device due to non-correction of the characteristics of the load controller provides increased accuracy in the optimization of the start-up process.

The device can be used to automate the control of the alternating regimes;

power plants.

Claims (1)

Invention Formula A device for automatic start-up of a turbine, containing a loading controller with metal temperature and turbine load sensors, an adder and a non-linear transducer, characterized in that, in order to improve the optimization of the start-up process, the load sensor output through the transmitter is connected to the adder metal temperature sensor, and the output of the adder through the second nonlinear converter is connected to the input of the controller. Rig