SU1420496A1 - Method of continuous measurement of combustion heat - Google Patents

Abstract

The invention relates to the field of thermophysical measurements of the properties of substances, in particular, to a method for continuously determining the heat of combustion. The purpose of the invention is to reduce the determination error. The measuring and comparative cells are placed under identical conditions. The working mixture is continuously fed into the measuring cell and the process of complete combustion of the fuel is carried out. Combustion products are removed and the heat flow between the cells is continuously recorded. Then, the heat emissions in the cells are equalized and the magnitude of the compensating thermal power in the comparative cell is measured. In order to reduce the error, the determinations to the measuring and comparative cells simultaneously supply the same thermal power during the operating time setting. Again, heat generation in the cells is measured, the total heat output is measured and the heat of combustion is determined. 1 il. i (L

Description

The invention relates to a technique for the thermophysical measurement of the properties of substances, namely the heat of combustion of liquid and gaseous fuels, and can be used in thermal power engineering, as well as in other industrial areas,

The purpose of the invention is to reduce the error of the continuous determination of the combustion glitch of liquid and gaseous fuels.

; The drawing shows the thermal scheme of the method for continuous determination of the heat of combustion,

The specific implementation of the proposed method is based on the implementation of a differential thermal circuit, including measuring 1 and comparative 2 cells, which, to ensure identity, are placed in an isothermal shell 3, on the surface of which they are supported; constant average temperature T ,,. The working mixture of the explored fuel with an oxidizer is continuously fed through nozzle 4 to the measuring cell 1 and the process of complete combustion of the fuel is carried out using a gas-burning device 5. At the same time, the heat output is released. The combustion products are discharged through the nozzle 6, providing an approximate equality ( with an error of 0.1%) of the physical heat introduced into the measuring cell with the working mixture, physical heat carried away with the combustion products, for example, due to the equality of temperatures of the working mixture. at the entrance to the cell and the combustion products at the exit from it.

The thermal power Q x obtained is compared with a heat gap in the comparative cell QO from a reference heat source 7, for example, an electric heater. For this purpose, the heat flux Q-j- is continuously recorded between equal opposite squares of the outer surface of the measuring and comparative cells using heat meters, the electrical signal from which is measured using precision instruments. Further, the measurement process is characterized by the fact that the heat emission in cells (i.e., condition Q. 0) is equalized with heat meters, by adjusting the heat power of the reference source and measuring the compensating heat power QO in the comparative the cell. The thermal power of the heaters can be controlled using commercially available devices of the BPT-2 type, and its measurement can be made according to the magnitude of the current and voltage in the heater circuit, the value of which is determined by the device of the Shch-68002 type.

In order to reduce the measurement error, the same thermal QO power is additionally simultaneously supplied to the measurement and comparative cells using electric heaters 8 and 9 with a half-time equal to the measurement time, then the thermal gaps in the cells are again aligned by adjusting the thermal power of the reference heat source 7 to measure the total thermal power in a comparative cell Q and determine the heat of combustion Q, by the formula

O 0

 X 0

Claims (1)

Invention Formula The method of continuous determination of the heat of combustion, consisting in that the measuring and comparative cells are placed under identical conditions, the working mixture is continuously fed into the measuring cell and the process of complete combustion of fuel is carried out, the combustion products are removed and the heat flow between equal in area parts of the outer surface of the measuring and comparative cells, then heat dissipation in the cells is equalized and the value of the compensating thermal power is measured in Noah cell, characterized in that, in order to reduce the determination error, the same heat and new power are simultaneously supplied to the measurement and comparative cells at the same time during the establishment of the operating mode, the thermal gaps in the cells are again aligned, the total thermal power is measured are the heat of combustion by the formula Q Q  X t QR - Q. 31420496 de Q c is the amount of heat released per unit time in the measuring cell, W; . five . Q rt is the amount of heat additionally released, a unit of time in the comparative and measuring Q cells over time. setting the operating mode, W; the amount of heat released per unit time in a comparative package, respectively, before the introduction of the thermal power QJ into it and after the introduction of Q | (total heat output), W, BbfX.off has 1 sided Editor A. Ogar Compiled by Belovodchenko Tehred A. Kravchuk Proofreader A. Obruchar Order 4324/49 Circulation 847 VNIIPI State Committee of the USSR for inventions and discoveries 113035, Moscow, Zh-35, Rauschska nab, 4/5 l working entrance Subscription