Condensation heat-transfer experiment device capable of realizing coupling of natural circulation and forced circulation

Abstract

The invention provides a condensation heat-transfer experiment device capable of realizing the coupling of natural circulation and forced circulation. The condensation heat-transfer experiment device mainly comprises a steam supply system, an air supply system, a helium gas supply system, a natural circulation cooling system, a forced circulation cooling system, a condensing experiment body and a data measurement and acquisition system. The non-condensable gas containing extra-steam-pipe external condensation heat transfer experiment research under natural circulation and forced circulation cooling conditions and the experiment research on the heat extraction and flow characteristics of a natural circulation system under the conditions that the heating power is stable and changed can be realized. The device can monitor the experiment data in real time and continuously measure the condensation characteristics under different mixed gas compositions, and therefore, the device carries out measurement accurately and carries out data processing rapidly. In addition, the degree of visibility of a whole system is extremely high; and through the observation on experimental phenomena, the understanding on experimental processes and the in-depth study on heat transfer and flow mechanisms are facilitated.

Description

technical field [0001] The invention relates to a condensation heat transfer experimental device, in particular to a condensation heat transfer experimental device capable of realizing the coupling of natural circulation and forced circulation. Background technique [0002] Condensation heat transfer is a form of heat transfer that occurs when steam comes into contact with a wall below its saturation temperature. Because condensation heat transfer can obtain high heat transfer coefficient from low temperature difference, it is widely used in many fields such as power, chemical industry, refrigeration and nuclear energy. Enhancing the heat transfer capacity of steam condensation is of great significance to improve the thermal efficiency of heat exchangers. However, non-condensable gases such as air have a strong inhibitory effect on condensation heat transfer. For example, air with a mass fraction of 1% in water vapor can reduce the heat transfer coefficient. 60%, so its qua...

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Problems solved by technology

However, judging from the published literature and patents, most of the condensation experimental devices proposed at present can only complete the experimental research of pure steam, or the mixed gas experiment under a single cooling mode.

Such as: MIT H.Liu's passive containment heat export experimental device (H.Liu, N.E.Todreas, M.T.Driscoll.An experimental investigation of passive cooling unit for nuclear plant containment[J].Nuclear Engineering and Design, 2000 , 199: 243-255.) can only complete the condensation experimental research under natural circulation; and the vertical tube external condensation experimental device of Dehbi of the Massachusetts Institute of Technology (Dehbi. The Effects of Non-condensable Gases on Steam Condensation under Turbulent Natural Convection Conditions, 1991.) can only complete condensation experiments under forced circulation

Moreover, the above-mentioned experimental device also has the following defects: (1) the steam source is arranged inside the experimental body, which requires a large water space to maintain the stability of data measurement, resulting in a large volume of the experimental body, which has a great impact on the experimental site, cylinder strength and sealing. If the test body is small in size, frequent replenishment of water will cause large fluctuations in the system pressure, and even cannot be stable at all, which cannot meet the measurement accuracy requirements

(2) For H.Liu's natural circulation test device, the condensation heat transfer is determined by the total latent heat of vaporization of saturated water in the water tank, which leads to the fact that the starting temperature of the coolant experiment must be the saturation temperature, so it cannot be used in a wide range Internal research on the effect of subcooling degree of heat exchange tube wall on condensation heat transfer

(3) H. Liu's experimental device is mainly for heat transfer research, without considering the thermodynamic characteristics and flow characteristics of the external natural circulation cooling system

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