In-situ test method for high-pressure low-temperature heat conductivity coefficients and heat transfer coefficients

Abstract

The invention discloses an in-situ test method for high-pressure low-temperature heat conductivity coefficients and heat transfer coefficients. The heat conductivity coefficients and the heat transfer coefficients of media are measured based on a point heat source thermistor method. The power of a thermistor is determined, and the heat conductivity coefficient and the heat transfer coefficient of a measured medium are obtained according to the resistance feedback and temperature attenuation data of the thermistor by utilizing a calculation model. The method comprises the following steps: correcting parameters of a thermistor measurement model; slowly extruding a to-be-measured medium by utilizing a piston on the lower part of a reaction kettle, and unifying the standard of to-be-detected samples; introducing reactive gas and controlling the pressure and temperature in a target range; and inputting the determined power value into the thermistor by virtue of a power input control system, acquiring the resistance value and temperature value of the thermistor by utilizing a data acquisition device, and finally, obtaining the heat conductivity coefficient and the heat transfer coefficient by utilizing the calculation model. According to the design of the invention, in-situ synthesis of different media under high pressure and at low temperature can be met, and in-situ measurement of the heat conductivity coefficients and heat transfer coefficients of multi-phase condition substances in different spaces and different time is realized.

Description

technical field [0001] The invention relates to an in-situ testing method for high-pressure and low-temperature thermal conductivity and heat transfer coefficient, belonging to the technical field of heat transfer testing. Background technique [0002] The point heat source measurement system based on thermistor is a relative measurement method for measuring the thermal conductivity and heat transfer coefficient of different media. The power specified by the thermistor is supplied by a regulated DC power supply, and the thermistor is in direct contact with the measured object. According to the temperature decay data of the thermistor itself and the calculation model, the thermal conductivity and heat transfer coefficient of the medium to be measured are calculated. This technical method can be applied to measure the internal thermal conductivity and heat transfer coefficient of different porous media under different conditions. By using the high-pressure sealing device, the ...

AI Technical Summary

Problems solved by technology

The traditional hot wire method and flat surface heat source method are widely used to measure the thermal conductivity of samples under normal pressure conditions, but less used under low temperature and high pressure conditions, especially in the presence of multiphase conditions. Operational convenience is poor

In addition, because the traditional hot wire method and the flat surface heat source method usually generate a large amount of heat, under the coexistence of multiphase substances, it is easy to cause changes in the physical properties and states of the multiphase substances, resulting in large measurement errors. In the application There are certain limitations in the process, and the simultaneous measurement of thermal conductivity and heat transfer coefficient has not been realized in the traditional hot wire method and flat surface heat source method.

At present, there is no report on the in situ measurement of thermal conductivity and heat transfer coefficient in multiphase state under high pressure and low temperature conditions.

Images