SU734743A1 - Device for determining reduced r.p.m. of gas-turbine rotor - Google Patents

Description

one

The invention relates to an automatic device and can be applied in automatic control systems of a gas turbine engine (GTE), as well as in devices of primary information of instrument complexes with centralized processing of information on a digital computer.

Devices are known for calculating the reduced rotational speed of a rotor of a turbocharger, consisting of an inlet air temperature sensor, the output of which is connected via a non-linear device to an inlet of a separating device, the second input of which is connected to an output of a rotational speed sensor of a rotor of a turbo-compressor

A disadvantage of this device is the dynamic error in calculating the reduced rotor frequency of the turbocharger × f, p, due to the dependence of the dynamic error of the intake air temperature sensor on the engine operating conditions.

A known system using a device for calculating a reduced rotor speed for controlling a gas turbine engine, which consists of a rotor speed knob of a turbo-compressor, is connected to the input of a calculating device, the other input of which is connected to an input temperature sensor. air 2.

The disadvantage of this device is the presence of a dynamic error in the intake air temperature sensor, depending on the engine flight conditions, which leads to an inaccurate calculation with a rapid change in the temperature of the intake air.

The closest technical solution to the present invention is a device containing a temperature sensor. the inlet air, the first output of which is connected to the first inlet of the adder, and the second inlet through the differentiator is connected to the inlet of the multiplying device 37 STS1, on /.the service of which the input of the air pressure sensor behind the compressor is fed through the nonlinear device, and the outlet is connected to the second inlet an adder, the output of which through the device for extracting the square root is fed to the first input of the separating device, the input of which is connected to the output of the rotor speed sensor of the turbocharger sj. The disadvantage of this device is an approximate correction of the time constant of the inlet air temperature sensor according to the pressure behind the compressor, since the formula for correcting the time constant of the temperature sensor only approximately corresponds to its actual change. In addition, the device has low noise immunity due to the presence of a differential that determines the magnitude of the derivative of the output signal of the inlet air temperature sensor, which is in the canape for calculating the reduced rotation frequency of the rotor of the turbocharger. The purpose of the invention is to increase the dynamic accuracy and noise immunity of the device. The goal is achieved in that the device contains a comparison key, an integrator, a second and third nonlinearity blocks, a rotor speed sensor, a second pressure sensor, and a second, third, and fourth dividing unit, and the temperature sensor output through the square root extractor is connected to another input of the first division unit, the output of which is connected to one input of the comparison unit, the other input of which is connected to the output of the adder, and the output to one input of the key, the other input of which through the third unit is It is connected to the differentiator code, the key output through the integrator is connected to one input of the summator, the other input of which is connected to the output of the third division block, the outputs of which through the first and second nonlinearity block are connected respectively to the outputs of the second and fourth division blocks, the first inputs of which are connected to the output the second pressure sensor, the output of the first pressure sensor is connected to the second input of the second dividing unit, and the output of the acceleration sensor of the rotational speed of the rotor is connected to the quad inlet dividing unit. 4 The effect of increasing the dynamic accuracy of calculating the reduced rotor speed, as well as increasing the noise immunity of the device, achieved in this device is justified by the following calculated data. The inlet air gas temperature sensor is a thermocouple, the dynamic properties of which are described by the equation e - a signal from the thermoconverter; T is the time constant of the thermal converter; K- is the transfer coefficient of the thermal converter; incoming air temperature Vha. The dynamic component of the measurement bounds is V 1 / m a - g L-1-et-e arG, and the time constant of the thermal transducer varies depending on the flight conditions and the engine operating mode, which leads to an inaccurate calculation of the reduced frequency rotation of the rotor of the turbocharger with a rapid change in Tj. Therefore, it is proposed to determine indirectly to determine the dynamic calculation error. As is well known, there is a relationship between the degree of pressure increase at the compressor and the value of PR n: fci - s, the heat rise pressure at the compressor; K is the adiabatic index for air; P. .. given the rotational speed of the rotor of the turbocharger; B is a constant value. However, this dependence is valid only for established GTE modes. In the presence of an acceleration frequency of rotation of a rotor of a turbocompressor, this dependence takes the form ICj V N., .Rr- (|) (4) A - a constant value; the rich entrance to the ferret; - acceleration of the rotation frequency of the turbocharger rotor. By the formula (4), the reduced rotational speed of the rotor of the turbocharger is equal to vHr (p LH pr drTir - the air pressure at the engine inlet; the air pressure behind the compressor. The sensors used to calculate the Idr are inertia-free, therefore there will be no dynamic calculation error. On The drawing shows a block diagram of the device. The device includes a temperature sensor 1, a square root extraction unit 2, a first dividing unit 3, a rotor speed sensor 4, a first pressure sensor 5, a second dividing unit 6, a second pressure sensor 7, ne third nonlinearity unit 8, third dividing unit 9, second nonlinearity unit 10, fourth dividing unit 11, rotor speed acceleration sensor 12, sum 13, comparison unit 14, key 15, integrator 16, differentiator 17, third nonlinearity unit 18. The intake air temperature sensor 1 is fed through the extraction unit of the square root 2 to the inlet of the first dividing unit 3, the second input of which is provided to the output of the sensor 4 for the rotation frequency of the turbocharger rotor. The output of the first air pressure sensor 5 downstream of the compressor is connected to the inlet of the second dividing unit 6, to the second input of which the output of the second pressure sensor 7 is fed to the compressor inlet. The output of the second dividing unit 6 through the first nonlinearity unit 8 is connected to the input of the third 9th unit, the other input of which is connected via the second nonlinearity unit 10 to the output of the fourth dividing unit 11, the inputs of which have the second pressure sensor 7 at the inlet to engine and acceleration sensor of rotational speed of the rotor 12 of the turbocharger. 45 The output of the third block O to; they are fed to the input of the adder 13, the output of which is connected to the input of the comparison unit 1-1, the other input of which is connected to the output of the first dividing unit 3, and the output through 1SLUT 15 and the integrator 16 is connected to the input of the adder 13. At the same time, the output of the inlet air temperature sensor 1 through the differentiator 17 and the third nonlinearity block 18 is applied to the control input of the switch 15. The device operates as follows. When the temperature of the incoming air, measured by temperature sensor 1, changes, a signal appears at the output of differentiator 17. If its value is larger than the dead zone of the third nonlinearity block 18, then key 15 connects the input of integrator 16 to the common bus. At the same time, the signal from the inlet air temperature sensor 1 through the square-root extraction unit 2, where the signal is formed, is supplied to the first dividing unit 3, to the second input of which a signal from the rotor speed sensor 4 of the turbo-compressor is supplied. In the first division unit 3, the magnitude of the reduced rotation frequency is calculated and fed to the comparison unit 14. Signals from the first and second pressure sensors 5 and 7 are supplied to the inputs of the second dividing unit 6, and the output signal of the second dividing unit 6 is through the first nonlinearity unit 8, where the signal is fed to the input of the third dividing unit 9. The dividing unit 11 receives signals from the pressure sensors at the inlet to the engine 7 and accelerating the rotor speed of the turbocharger 12, and the output from the fourth dividing unit 11 through the second nonlinearity unit 1O, which forms a p ng - 1: - 1, P 3) and the second input of the third block Y division, where the reduced rotation frequency is calculated by an indirect method. When the output signal of the differentiator becomes less than the dead zone of the third nonlinearity block 18, which corresponds to the static mode of operation of the device, the key 15 closes the output of the block 14 in comparison with the input of the integrator 16, the output signal of which

Claims (1)

Claim A device for determining the reduced rotor speed of a gas turbine engine, comprising a temperature sensor, the output of which is connected to a differentiator, a rotor speed sensor connected to one input of the first division unit, an adder, a square root extraction unit, the first ⁴⁵ nonlinearity unit, and the first pressure sensor , characterized in that, in order to increase the dynamic accuracy and noise immunity of the device, it contains a comparison unit, a key, an integrator, second and third blocks of nonlinearity, an acceleration sensor Ia rotor speed, a second pressure sensor and the second, third and fourth blocks tsele10 Nia, the temperature sensor output from the square root unit is connected to another input of the first divider, the output of which is connected to one input of the comparator, the other 15, the input of which is connected to the output of the adder, and the output to one input of the key, the other input of which is connected to the output of the differentiator through the third nonlinearity block, the output of the key through the integrator is connected to one input of the adder, the other input of which is connected to the output of the third division unit, which outputs via the first and second blocks nonlinearity respectively connected to the outputs ²⁵ of the second and fourth dividing blocks, the first inputs of which are connected to the output of the second pressure sensor, first outlet pressure sensor is connected to a oromu input of the second dividing unit, as you move the acceleration sensor ^30, the rotational speed of the rotor is connected to a second input of the fourth divider.