A visual experimental device for CHF research in a rectangular narrow channel with adjustable spacing

Abstract

The invention provides a CHF research visualization experiment device in a rectangular narrow channel with adjustable spacing. A rectangular quartz glass tube surrounds a rectangular heating rod to form a narrow rectangular flow channel; The through hole of the connecting flange flows into the narrow rectangular channel, and after full development, it is heated by the heating rod to increase the temperature, and finally flows out from the through hole of the upper connecting flange; the positive pole of the power supply is added through the slit between the connecting flange and the pressing flange. On the upper electrode, the negative electrode is connected to the lower electrode, and an insulating gasket is added between the electrode and the flange to achieve insulation; the thermocouple is arranged on the inner surface of the rectangular heating rod, and is drawn out through the heating rod and the hollow part of the upper electrode, which can conduct heat through heat conduction. Differential equations indirectly measure the temperature distribution of the heated surface; a rectangular quartz glass jacket is fitted with a pressure-bearing glass sleeve. The invention can provide theoretical basis for the design of the reactor, and at the same time guarantee the operation of the reactor under normal and accident conditions.

Description

technical field [0001] The invention relates to a CHF research visualization experiment device in a rectangular narrow channel with adjustable spacing, and belongs to the field of flow boiling visualization research. Background technique [0002] CHF (Critical Heat Flux) is the heat transfer limit of flow boiling. Accurately predicting the value of critical heat flux is of great significance for reactor design and operation under accident conditions. Plate-type fuel assemblies with rectangular narrow channel features are widely used in research and experimental reactors and integrated reactors because of their compact structure, low fuel pellet temperature, and large heat transfer area. Some of the existing empirical relations for predicting the critical heat flux in narrow rectangular channels are all fitted based on their own experimental data. The accuracy depends strongly on the similarity of the experimental conditions and cannot be extended to other conditions. Theref...

AI Technical Summary

Problems solved by technology

During the installation process, it is impossible to ensure that all the bolts are screwed to the same degree, which results in different clearances at different sections of the rectangular flow channel.

Secondly, the traditional rectangular channel experimental device can only photograph the aggregation behavior of the bubbles from the front, and cannot observe the growth of the bubbles and some important parameters that affect the critical heat flux density, such as the thickness of the bubble layer, etc.

Finally, the channel gap of the above-mentioned experimental device is fixed, so it is impossible to study the influence of the gap effect on the flow

Images