SU1332165A1 - Device for measuring the enthalpy of high-temperature gases - Google Patents

Abstract

The invention relates to thermometry and allows for improved measurement accuracy. The calorimetric element 2 of the device is made in the form of a ring-reinforced 5-cylinder 4 made of porous metal fixed on the inner surface of the housing 1 s by the power of a conical membrane 6. The differential temperature at the edges of the membrane 6 is measured by diff. thermocouple 7, formed by housing 1, membrane 6 and ring 5. The magnitude of the temperature difference can be controlled by selecting the thickness and taper of membrane 6. To determine the gas enthalpy, the gas flow rate is measured by a flow meter 3. 1 sludge. 00 with sD

Description

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The invention relates to heat measurements and can be used to measure the enthalpy of deceleration of high-temperature flows: gases in experimental aerodynamics, heat engineering and heat power engineering.

The purpose of the invention is to increase the measurement accuracy.

The drawing shows a device for measuring enthalpy. A device for measuring enthalpy. The FDI contains a cooled body 1, a calorimetric element 2 placed in the body 1, and a flow meter 3. in the form of a flow meter, including means for measuring the pressure drop across the flow meter and a device for measuring the temperature of the gas before the flow meter. The calorimetric element 2 is made in the form of a cylinder 4 of porous metal and is reinforced with a ring 5. A conical membrane 6 is used to fasten the calorimetric element 2 on the inner surface of case 1. Case 1, conical membrane 6 and ring 5 are made of thermoelectrode materials: copper — constantan — copper and forms a differential thermocouple j, Conclusions 7 of which are connected to an appropriate recording device (not shown). Using this differential thermocouple, the temperature difference between the edges of the conical membrane 6 is measured.

The device works as follows

The device is installed in a controlled stream of high-temperature gas and a sample of gas begins to flow into its internal channel. The calorimetric element 2 is then heated to some equilibrium temperature at which the heat leakage from the calorimetric element 2 to the cooled body 1 becomes equal to the amount of heat entering the calorimetric element 2 from the gas sample flowing through it. After reaching the steady state mode, the temperature difference on the conical membrane 6 and the flow rate of the gas flowing through the device are measured. From the magnitude of the temperature difference across the conical membrane, the amount of heat given off by the flowing gas is calculated. Authentic

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data on the relationship between the quantities: temperature difference, measured using a differential thermocouple 7, and the amount of heat, obtained by direct calibration using a heating element embedded in the calorimetric element 2. The electrical leads from the heating element on the same line are indicated by the position 8, Using the calibration characteristic, the amount of heat given off by the flowing gas is determined. The ratio of this amount of heat to the flow, get the desired value of the enthalpy of gas.

In order to exclude heat leaks from calorimetric element 2 to housing 1, in addition to conical membrane 6 and heating of said element with 2 portions of gas, do not pass through 1 device through the device, the gap between calorimetric element 2 and the inner surface of housing 1 should not exceed 0.3-0. 5 mm.

The magnitude of the temperature difference on the conical membrane 6 can be controlled by an appropriate choice of the mass and taper of this membrane.

The implementation of the calorimetric element 2 and the porous metal makes it possible to significantly increase the efficiency of heat exchange by increasing the contact area and easier flow turbulization,

To take into account the amount of heat not given off by gas to the calorimetric element 2, one can use the readings of the thermocouple included in the gas flow meter.

Claims (1)

Invention Formula A device for measuring PII of high-temperature gases containing a cooled flow housing containing a calorimetric element and a flow meter, characterized in that, in order to improve the accuracy, the calorimetric element is made in the form of a ring-reinforced porous metal cylinder and fixed to the inner surface of the housing is sealed with a conical membrane, and the housing, the membrane and are made of thermoelectrode materials and form a differential thermocouple. Editor G. Volkova Compiled by V. Shilov Tehred M. Khodanich Proofreader I. Muska 3823/37. Circulation 776 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4