SU70770A1 - Device for measuring the temperature of rotating machine parts - Google Patents

Description

Measuring the temperature of rapidly rotating bodies and fast moving media (gas in turbines, fast rotating rotors, etc.) is currently extremely difficult. Conventional methods for measuring temperature using thermal expansions of bodies or thermocouples cannot be used here, since it is very difficult to make a conventional thermometer rotate with the rotor or move with gas. However, the use of electrical methods for measuring temperatures is complicated by the need to use sliding contacts that provide parasitic s. D. s., which dramatically reduces the accuracy and reliability of measurement. At the same time, the presence of sliding contacts leads to a complication of the structure.

The proposed device allows eliminating the aforementioned underage;

It is based on the use of a known method for measuring temperature using ferromagnetic

bodies whose magnetic properties vary depending on the temperature and which is placed in the air gap of the electromagnet included in the electrical measuring instrument circuit so that a change in temperature causes a change in the electrical state of the electromagnet and leads to a corresponding deflection of the electrical indicator instrument.

The essence of the invention. is that a ferromagnetic body (or a series of such bodies) is mounted on a controlled part (which can be either dia- or paramagnetic or ferrol-magnetic) and periodically passes through the above-mentioned air gap, exciting electrical pulses in the winding of the electromagnet, the intensity of which depends on temperature. In such a device, a permanent magnet carrying the generator winding can be used instead of an electromagnet.

The foregoing explanation of FIG. 1 and 2. In FIG. 1 shows the layout of the device299

measuring the temperature of the periphery of the turbine rotor, and FIG. 2 is another device variant.

In the diagram shown in FIG. 1, denoted: 7 — turbine stator, 2 — rotating rotor, 3 — rotor blades, 4 — magnet, 5 — coils worn on the pole tips of a magnet, 6 — ferromagnetic body fixed on the periphery of the rotor entering the air gap between the pole magnet tips, 7 - voltmeter included in the circuit of the coils 5.

The body 6 is made of an alloy with a previously known dependence of the magnetic permeability on temperature. With each rotation of the rotor, the body 6 will close the magnetic circuit of the magnet and thus direct in the coils 5 e. d. Largest induced e. d. You can judge the temperature of the periphery of the rotor, where the body is 6.

There are alloys which, at a certain temperature, transfer from a ferromagnetic state to a paramagnetic one and vice versa. The temperature of such a transition is called the Curie point. When the alloy reaches this temperature, the magnitude of the induced em. d. changes dramatically.

Using a set of alloys with different Curie points and observing which of them crossed the Curie point, it is possible to determine the temperature of the medium where the alloy is. This option gives a stepwise temperature measurement, with the step size being determined by the temperature difference between the Curie points of the used alloys. An exemplary design of the device in this embodiment is given in FIG. 2. Here 7 is a turbine stator, 2 is a rotor, 4 is a soft iron magnetic circuit, 5 is an electromagnet winding, 6 are bodies of ferromagnetic material, 7 is a galvanometer, 8 is a battery, 9 is a transformer in an electromagnet 4-5, 10 - amplifier, 77 - oscilloscope.

When measuring the temperature with the proposed device, it is possible to use resonant methods, since usually during the operating mode the rotor (or gas) rotates at a certain number of revolutions. The use of resonance methods, however, allows filtering out interferences caused both by the imperfection of the manufacture of the instrument and the materials of its parts.

Subject invention

Claims (2)

1. A device for measuring the temperature of rotating machine parts using a ferromagnetic body, whose magnetic properties vary depending on temperature and which is placed in the air gap of an electromagnet connected to an electrical measuring circuit so that a change in temperature causes the electromagnet to change to a corresponding deviation of the electric measuring instrument index, characterized in that the ferromagnetic body (or a series of such bodies) is fixed on the control Rui part so that it passes through said periodically vozduschny gap electromagnet coil is excited in the electrical pulses, the intensity of which depends on the temperature. 2. The device modification according to claim 1, consisting in using a permanent magnet, instead of an electromagnet, that carries the generator winding.