SU922540A1 - Device for measuring temperature of gas flow - Google Patents

Description

I

The invention relates to thermometry, namely, to the measurement of the instantaneous temperatures of a non-thermal-gas turbulent flow.

A device for measuring the temperature of a gas stream comprising a tube and a measuring element O) is known,

However, the known device does not have the required accuracy of the measured non-stationary temperature due to the error due to the inertia of the measuring element.

Closest to the proposed technical entity is a device for measuring the temperature of the gas stream, containing a full head tube and measuring elements 2.

However, the known device does not have the required measurement accuracy due to the error due to the inertia of the measuring

elements and dependence on the molecular mass and heat capacity of the measured gas.

The purpose of the invention is to improve the accuracy of measuring the instantaneous values of the temperature of the turbulent flow, for which the damping elements and the shyarrow droplet are introduced into the device. g; mudflow, fixed on the full head tube and connected by an additional tube to the damping and measuring elements, the second damping element is mounted on the tube completely. A head of equal diameter with an additional tube and the measuring elements are made in the form of highly sensitive pressure sensors, with the ratio of the areas of the channel of the additional tube and the gap throttle being selected between 10 and 15.

The drawing shows the proposed device. 39 The device contains a pressure head 1, pressure damping element 2, a high-sensitivity sensor 3, pressure throttle, an additional tube, a damping element 6, and a highly sensitive pressure sensor 7. The device operates as follows. When immersed in a neurothermal flow, tube 1 senses pulsations of the full head or pulsations of the dynamic head in the absence of pressure gradients. The non-electric signal in sensor 3 is converted to Electric and recorded on a secondary device, such as an oscilloscope. The curve recorded by the pressure pulsations contains all the necessary information about the flow parameters, since the pulsations can be caused not only by velocity pulsations, but also by density pulsations, and hence temperature. To isolate the effect of density, a slit choke C and tube 5 with pressure sensor 7 are used. If tubes 1 and 5 have the same characteristics recorded on the oscilloscope using sensors 3 and 7, the pressure pulsation curves will have the same character, will coincide in phase, but will be numerically different. This difference in the measured instantaneous values of the pressure pulsations represents the energy loss during the pulsation movement through the choke. The magnitude of these losses is determined not only by hydrodynamic conditions, but also by the physical properties of the medium with density and viscosity jt4 ,. Thus, sensor 3 senses the magnitude of the total pressure pulsations consisting of a number of tPnoftM terms), and sensor 7 senses a pressure somewhat different from the readings of sensor 3 PnoAHb PcT MiHli + P,

PCT

static pressure; P

average velocity

head;

H

pulsating composition

conductive velocity head

accepted by sensor 3;

For the manufacture of tubes 1 and 5, injection needles with a diameter of 1 mm or 1.2 mm are used. Tube length

Claims (2)

It is selected experimentally so that the own acoustic frequencies of the systems tube 1 - sensor H - pulsation component of the velocity head detected by sensor 7. Pressure H in throttle space depends on the parameter as the choke t is at an angle of 90 to the velocity vector, then pressure pulsations in the tube 5 will only be determined by the magnitude of a certain head caused by the full head pulsation. The sensor 7 registers the pulsations, the value of which is where a is the coefficient of the tube. If the energy losses during a pulsating flow through a choke are attributed to Hj, then from the energy balance, taking into account the temperature dependences of p and ju, we obtain a relationship between the pulsation parameters of the system and the pattern relating the instantaneous temperature of the flow to the total pressure pulsation. . where, lfl - physical parameters of the medium, referred to the initial temperature Te, at which the device was calibrated; H - the magnitude of the pulsation of the velocity head, is removed from the oscillogram of the sensor 3; - - slit throttle hydraulic resistance coefficient determined by the Curves of recording pulsations r by sensors 3 and 7. To ensure that the pressure difference H and .H ,, is sufficient, the ratio of the cross-sectional area of the tube and the throttle is chosen within mp / € 10- 15. 3 and tubes 5 - sensor 7. were identical. Measuring the temperature of the gas flow with the proposed device showed that it has a higher accuracy compared to that known, which will improve the quality of control over a number of technological processes. Claim 1. Device for measuring the gas flow temperature, containing a full head tube and measuring elements, characterized in that, in order to improve the accuracy of measuring the instantaneous values of turbulent flow temperatures, damping elements and a slit throttle inserted on the tube are inserted into the device full head and connected with an additional tube with damping and measuring elements, the second damping element is mounted on a full head tube, which is made of equal diameter with Modes tube, and measuring elements are in the form of highly sensitive pressure sensors. 2. The device according to claim 1, so that in order to increase the resolution, the ratio of the areas of the channel of the additional tube and the gap throttle is selected in the trajectory. 10-15. Sources of information accepted in the attention in the examination 1. The author's certificate of the USSR № 82647, cl. G 01 K 13/02, 04.03.49. 2. Free P.M. and others. The structure of the flame. M., Metallurgists, 1969, p.154 (prototype).