SU1682830A1 - Gas flow temperature measuring device - Google Patents

Description

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(21) 4646146/10 (22) 06.02.89 (46) 10.10.91. Byul. №37

(71) Kharkiv Aviation Institute. N.E. Zhukovsky

(72) A.A. Zavaliy, G.D. Simbirsky and T.I. Kvatashidze

(53) 536.532 (088.8)

(56) USSR Author's Certificate No. 823901.cl. G 01 K 11/22, 1981.

USSR Author's Certificate No. 1425474, cl. G 01 K 13/02, 1988. (54) DEVICE FOR MEASURING THE GAS FLOW TEMPERATURE

(57) The invention relates to thermometry. The purpose of the invention is to improve the accuracy of measuring high temperatures of gas streams under conditions of variable speeds and turbulence. The device contains a cooled measuring channel with two thermal converters on the axis and one thermal converter in the wall of the measuring channel. At the inlet and outlet of the measuring channel, an input narrowing and output narrowing-expanding nozzles are installed, respectively. Moreover, the area of the flow area of the output nozzle exceeds the area of the flow area of the input nozzle by more than 2 times. The measuring channel is placed in a cooled suction channel, at the entrance to which a narrowing nozzle is installed in the form of a sharp-edged diaphragm. Moreover, the aperture area of the diaphragm is not less than the inlet nozzle area, and a device for changing the gas flow is installed at the outlet of the suction channel. 2 Il.

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The invention relates to contact thermometry and can be used to measure high temperatures of gas streams.

The aim of the invention is to improve the measurement accuracy in a gas stream with variable velocity and turbulence.

Fig. 1 shows a device for measuring the temperature of a gas stream, a general view; figure 2 - section aa in figure 1.

The device comprises a cooled body 1, a pipe 2 of a cooled measuring channel, two thermal converters 3 located on the axis of the pipe 2 of the measuring channel, a thermal converter 4 located in the wall of the pipe 2, a narrowing nozzle 5 at the entrance to the pipe 2 and a narrowing-expanding nozzle 6 at the outlet from the pipe 2, the pipes 7 of the cooling jacket form a suction channel 8, at the entrance to which an inlet diaphragm 9 is installed, and at the exit - a device 10 for changing the gas flow through the suction channel 8. A cooling medium (for example, water) is fed into the jacket cooling through tube 11 and discharged from the device through tube 12.

The process of measuring the temperature of the gas stream is as follows.

From the device 10 and the nozzle 6, the gas stream under study is aspirated. At the same time

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The nozzles 5 and 6 establish a supercritical pressure drop. The device 10 provides the maximum flow through the suction channel 8 and, accordingly, the minimum pressure and density behind the diaphragm 9 (for example, the density is 1 Kr / M j.

A gas whose temperature, for example, is equal to 2000 K, through the diaphragm 9 enters the suction channel 8. Then a part of the gas stream, while cooling, enters the device 10 and is discharged, for example, to the atmosphere. The second part of the gas flow flows through the measuring channel 2 with a speed of, for example, 50 m / s, the wall temperature of which, for example, is 300 K. As the pelvis cools in the measuring channel 2, its temperature drops along the channel and measured by thermocouples 3. For example, with the diameter of the measuring channel 2, equal to 5 mm. the distance from the entrance to the measuring channel to the thermal converters is 20 and 35 mm. Thermocouples 3 in this case measure temperatures of Ti 1600 K and Ta 1373 K. The values of h and Ta are recorded, and then device 10 reduces the gas flow through the suction channel 8, and the pressure in front of the nozzle 5 of the measuring channel 2 increases, for example, 1.2 kg / m3. At the same time, the gas flow rate through the measuring channel 2 increases and, consequently, decreases with the rate of gas temperature drop along the channel length. The readings of thermal converters 3 are recorded again, which in this case will show Ti 1700 K, Ta 1518 K. A is the value and the gas temperature is found to be Tg.

It should be noted that when pressure changes (density) are realized

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At the entrance to the measuring channel, the pressure (density) values need not be monitored. The control is carried out only according to the indications of thermocouples 3. For normal operation of the method, it is sufficient to create a difference, the temperatures of Ti and Ti in the range of 50-100 K.

Thus, high accuracy is obtained when measuring in streams with variable speed and turbulence.

Claims (1)

Apparatus of the Invention A device for measuring the temperature of a gas stream, comprising a cooled measuring channel, two thermal converters with slots on the axis of the measuring channel and a device for changing the gas flow, characterized in that, in order to improve the accuracy of measuring temperature in flows with variable velocity and turbulence , a cooled suction channel with a narrowing nozzle at the entrance is introduced into it in the form of a small-bore diaphragm and a third thermal converter, and a measuring channel, in the wall of which there is a tr This thermal converter is located in the cooling suction channel and is equipped with narrowing and narrowing-expanding nozzles, made respectively in the inlet and outlet sections of the measuring channel, the throat area of the outlet nozzle exceeds the cut area of the inlet nozzle by more than two times. the diaphragm is not smaller than the flow area of the inlet nozzle of the measuring channel, and the device for changing the gas flow rate is installed at the outlet of the suction channel. 3 To the ejector W.L s I To the ejector eleven Fie.2