Principle of high and low temperature test chamber

    high and low temperature test chamber When the air in the test box passes through the open water surface, heat and moisture exchange occurs with the water surface. Depending on the water temperature, only sensible heat exchange may occur, or both sensible heat exchange and moisture exchange may occur, as well as latent heat exchange. When the air in the air is in direct contact with the water surface, close to the water surface, due to the irregular movement of water molecules, a saturated air boundary layer with a temperature equal to the temperature of the water surface is formed, and the concentration of water vapor molecules or water vapor partial pressure depends on The saturated air temperature of the boundary layer.

high and low temperature test chamber If the concentration of water vapor molecules in the test chamber is greater than the concentration of water vapor molecules in the air above it (that is, the partial pressure of water vapor in the boundary layer is greater than that of air), the number of water vapor molecules in the air will increase; otherwise, it will decrease . The former is called "evaporation" and the latter is called "condensation". During the evaporation process, the water vapor molecules that have been reduced in the boundary layer are supplemented by the water molecules jumping out of the water surface. During the condensation process, there are too many water vapor molecules in the boundary layer. It will return to the surface of the water. It can be seen that the sensible heat exchange between air and water depends on the temperature difference between the boundary layer and the air above, and the moisture exchange and the resulting latent heat exchange depend on the water vapor molecules between the two. The concentration difference or partial pressure difference.

The dehumidification principle of the high and low temperature test chamber is that when the refrigeration system is working, the temperature of the evaporator surface fin will be lower than the dew point temperature of the test temperature. When the air circulates, the moisture will condense when passing through the evaporator surface to achieve the purpose of dehumidification.