SU148930A1 - Device for automatic determination of specific heat flux - Google Patents

Description

BASIC Auth. St. N9 148260 describes a device for automatic determination of the specific heat flux, containing a calorimeter, an automatic programmable controller of a quasi-stationary thermal regime, and a two-orient electronic recorder. However, this device cannot provide continuous and automatic determination of the specific heat flux in samples of solid materials.

Described device does not have this disadvantage. This is achieved by using electromechanical calculating units of a electroscopic type that serve to solve an equation of the form

g% If dt,

  Here: q is the specific heat flux, Ki and Kz are the constant values of ichinz and „is the instantaneous value of the voltage of the flat heater, and dt

resistance of the flat heater at a temperature of 20 ° and above

- derived from the temperature of the heater over time.

The drawing shows a functional block diagram of the described device.

The device 10 consists of a software automatic unit 1 for setting quasi-stable ionic and non-stationary thermal conditions, a block 2 of calorimeters used for conducting thermophysical experiments, and an automatic calculating unit designed to determine the specific heat flux q given by a flat heat source.

No. 148930-2 -

The copier 4, the reversing motor 5 and the program setting device 6 are used to set the non-stationary thermal mode, and the reversing engine 7 and the program setting unit 6 - to set the quasistationary thermal mode.

The automatic control system operating in the following mode contains thermocouples 8, 9, measuring device 10 of compensation type, electronic proportional-integral-differential controller //, and remote control 12 of manual and automatic control. Switching, manual and automatic control of the reversing motor / and heaters 14, 15 are performed by means of the console 12. One of the outputs of the engine 13 is connected to the voltage regulator 16.

To continuously determine the instantaneous values of the voltages proportional to the square of the voltage of the flat heater / 4, a multiplying device consisting of blocks 17, 18 serves. Continuous determination of the instantaneous values of the power of the electric current supplied to the heater is carried out using a linear potentiometer 19 and circuit 20 division. The potentiometer motor 19 moves synchronously with the linear and non-linear setting devices, as a result of which the value of the resistance change of the flat heater is continuously modulated depending on the temperature change of the flat heater.

A voltage proportional to the instantaneous value of the power of the electric current from the output of dividing circuit 20 is supplied to a subtractor 21. Power is supplied to the subtractor 21 and dividing circuit 20 from power supply unit 22. Thermograms that control the desired thermal conditions are recorded by means of an electronic potentiometer 23 on a chart tape 24, with a reohord of which an articulated P5 potentiometric sensor is displaced in proportion to the temperature of the heater. The voltage taken from the potentiometric sensor 25 is differentiated in block 26 and supplied to an automatic device containing a compensation-type measuring circuit 27, a voltage converter 28, an AC amplifier 29, a linear potentiometer 30, reversible; motor 31 and reproducing continuous balancing of the input derivative of

heater temperature settings using the device’s next step. The power of the potentiometric sensor 25 and the automatic device block is provided from power supply 32. The reversible motor 31 moves the balancing linear potentiometer 30 and the linear clamp gauge 33 connected to the subtractor unit 21.

The device 21 performs a continuous subtraction of voltages proportional to the instantaneous value of the power of the electric current supplied to the heater 14, and derived from the temperature with respect to time. Voltage proportional to the difference

and SI values, is fed to one of the inputs of the electronic

30 +

two-coordinate recorder 34. The second input of this recorder is supplied with a thermal EMF, proportional to the temperature of the heater. On

U

 HL /

The chart tape 35 of the recorder 34 records the specific heat flux of the flat heater as a function of temperature, of the heater.

The described device can be used to determine the thermophysical coefficients of plastics, heat insulating and all molecular materials.

Subject invention

Device for automatic determination of specific heat flux by aut. St. No. 148260, which contains a calorimeter, an automatic software controller for a quasi-stationary thermal regime, and a two-coordinate electronic recorder, distinguishes it with the fact that to ensure continuous and automatic determination of the specific heat flux in samples of solid materials, electromechanical-type calculating units are used to solve view ratio

, -K, R .. + R ,, L

- 3 - № 148930

(description by V.S. Kozlov

Editor N. S. Kutafin Techred A. A. Kamyshnikov Proofreader G. E. Kudr Vtseva

Sub. to furnace 9.VII-62 g. Format boom. 70X lOS / is, Volume 0.35 ed. l

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TsBTI Committee for Inventions and Discoveries at the Council of Ministers of the USSR

Moscow, Center, M. Cherkassky Lane, 2/6.

Printing house TsBTI, Moscow, Petrovka, 14.