SU1569628A1 - Apparatus for measuring internal indicated efficiency of compressor of screw type - Google Patents

Abstract

The invention relates to a measurement technique and makes it possible to simplify the measurement of the internal indicator efficiency of a screw compressor. For this, along with a piezoelectric pressure sensor 1 on the rotor 2 of the compressor 3, a current collector 4, a measuring amplifier 5, a rotation angle converter 6 of the rotor 2, an integrator 9 and a logometer 14, the device includes a rotor speed sensor in the form of an inductive sensor 10 and a driver 11, suction pressure sensors 15 and injection sensors 16, a logarithm converter 17, two multipliers 12 and 18, and a rotameter 19. At the output of the converter 17, a signal is generated that is proportional to the logarithm of the pressure ratio in the pressure cavities and suction, and the readings of the gauge 14 are proportional to the ratio of isothermal and indicator power of the compressor (i.e., isothermal or internal indicator efficiency), which makes it possible to estimate the energy efficiency of the gas compression process. 1 il.

Description

This invention relates to measure

technology and can be used

It is called for in systems of automatic regulation and control of operating parameters of screw compressors.

The aim of the invention is to simplify the measurements.

The drawing shows a block diagram of the device.

A device for measuring the internal indicator efficiency of a screw compressor contains a piezoelectric pressure sensor 1 mounted on rotor 2 of compressor 3 and connected via current collector 4 to measuring amplifier 5, rotor angle converter 6 made in the form of drum 7 with ferromagnetic tape and magnetic head 8, integrator 9, a rotor speed sensor of the compressor, made, for example, in the form of an inductive sensor 10 and forming a body 11 of pulses connected to the multiplier 12 to the second input of the co The integrator 9 is connected and the output of the multiplier 12 through the trimming resistor 13 is connected to one of the windings of the gauge 14. The device also contains two pressure sensors 15 and 16 installed on the compressor housing in the suction and discharge cavities of the working gas and connected to the inputs of the logarithm transform. A rotator 17, a multiplier 18, to the inputs of which an electrical output of a rotameter 19 connected pneumatically to the suction cavity is connected, a pressure sensor 15 and an output of a logarithmic converter 17. The output of the multiplier 18 is connected via a trimming resistor 20 to the second winding of the gauge 14. Displayed compressor 3 has a drive 21.

The device works as follows.

When the compressor is operating in a given mode, the signals from the piezoelectric sensor 1 and the transducer 6 of the rotation angle of the rotor 2 are fed to the inputs of the integrator 9, at the output of which an average indicator pressure signal is generated.

The inputs of the analog multiplier 12 receive signals from the rotor speed 2 and the average indicator pressure. The output of the multiplier 12 produces a current, the value of which is proportional to the indicator power

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of the indicated compressor 3. This current through the trimming resistor 13 enters one of the windings of the gauge 14. With the help of sensors 15 and 16 pressure. The absolute pressures of the compressed gas in the suction and discharge cavities of the working chamber of compressor 3 are recorded. Electrical signals from these sensors are fed to the inputs of the logarithmic converter 17, at the output of which a signal is generated that is proportional to the pressure and suction cavity arithmetic, respectively. At the same time, the volumetric gas suction capacity of the compressor is recorded with the help of a rotameter 19. Electrical signals from the rotameter 19, the pressure sensor 15 and the logarithmic converter 17 are fed to the inputs of a transmitter 18, the output of which produces a current whose magnitude is proportional to the isothermal power of the compressor 3. d) the current through the trimming resistor 20. goes to the second winding of the 14 gauge The readings of which are proportional to the ratio of isothermal and indicator power of the compressor, respectively. For screw maslozapolnennogo compressor, in

where the heat released during compression is removed by the cooling liquid, the value of the isothermal efficiency (i.e., the internal indicator efficiency) obtained from the gauge 14 reads the energy efficiency of the gas compression process by the compressor.

Claims (1)

Invention Formula A device for measuring the internal indicator efficiency of a screw compressor, containing a rotor angle converter, a rotor angle sensor, an integrator, a logometer, and a measuring amplifier mounted on the compressor rotor; its input is connected to a pressure sensor through a current collector; the output of the measuring amplifier is confirmed to the first input of the integrator; which is connected to the output of the rotation angle / rotor converter, which is different in that, in order to simplify the measurements, it is equipped with a speed sensor mouth ora, suction and discharge pressure sensors, logarithmically 515696286 transducer, two multiply-connected suction pressure sensors l mi and rotameter in the cavity of the suction and injection, to the inputs of the second AC no compressor, and to the inputs of the pen-knives are connected respectively of the second multiplier connected to the respective outputs of the rotameter, pressure sensor The sensor of the rotational speed of the suction and the logarithm converter and the integrator’s output, to the inputs of the apparatus, and the windings of the logometer A log converter is connected to the multiplier outputs.