Experimental device for condensation heat-exchange of steam containing multi-component non-condensable gases

Abstract

The invention provides an experimental device for condensation heat-exchange of steam containing multi-component non-condensable gases. The experimental device comprises a steam supply system, an air supply system, a supply system of other gases, a cooling water system and a condensation experiment body, wherein the condensation experiment body comprises a shell and an experimental pipe arranged in the shell; the upper part and the lower part of the shell are respectively provided with an upper gas inlet pipe and a lower gas inlet pipe; an upper gas inlet valve and a lower gas inlet valve are respectively mounted on the upper gas inlet pipe and the lower gas inlet pipe; a main pipeline, which is formed after the upper gas inlet pipe and the lower gas inlet pipe are connected in parallel, is connected with the steam supply system, the air supply system and the supply system of other gases; the bottom of the shell is connected with a condensate tank; the steam is condensed in the condensation experiment body, and then the condensate flows down into the condensate tank from the bottom of the shell and is drained through a drain valve; and the upper end and the lower end of the experimental pipe are connected with the cooling water system. According to the experimental device for condensation heat-exchange of steam containing multi-component non-condensable gases, external condensation heat-exchange experiments of vertical single pipes and pipe bundles in various sizes and structural forms can be performed, thereby studying effect mechanisms of stem flow direction, non-condensable gas layers and other factors on condensation heat-exchange.

Description

technical field [0001] The invention relates to a condensation heat exchange experimental device, in particular to a steam condensation heat exchange experimental device containing multi-component non-condensable gas. Background technique [0002] As a basic form of heat transfer, steam condensation can obtain a high heat transfer coefficient from a low temperature difference, so it is widely used in many industries such as energy, power, and chemical industry. 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 quantitative research has been a research hotspot in heat transfer and related fields in recent years. At present, in the field of seawater desalination, the condens...

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Problems solved by technology

Although the experimental device of MIT Dehbi (Dehbi.The Effects of Non-condensable Gases on Steam Condensation under Turbulent Natural Convection Conditions, 1991.) can carry out the condensation experiment outside the vertical tube, it has the following defects: (1) the steam source is set Inside the experimental body, a large water space is required to allow a long enough stable time for data measurement, resulting in a large volume of the experimental body, which has high requirements for the experimental site, cylinder strength and airtightness; if the experimental body volume Smaller, frequent replenishment of water will cause large fluctuations in system pressure, greatly shorten the stabilization time, or even fail to stabilize at all, which cannot meet the measurement accuracy requirements

(2) Due to the large density difference of each component of the mixed gas, the opposite steam flow direction will produce a completely different gas mixing effect, which will have a significant impact on the condensation heat transfer. The device cannot change the steam flow direction, and cannot study the steam flow direction on condensation. Effect of heat transfer

(3) The distribution of the non-condensable gas layer near the tube wall is of great value for the analysis of the inhibition mechanism of non-condensable gas on condensation heat transfer. The temperature and concentration parameters inside the gas layer are extremely important data support, but the device does not have Experimental research in this area cannot be carried out without any measuring device

(4) The steam flow cannot be measured and adjusted, and the heat transfer can only be measured through the cooling water side, and its accuracy cannot be verified by the steam side

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