Zhan Yu Industrial Corporation – What is the working principle of a heat exchanger?

The working principle of a table cooler is based on the principle of heat exchange. By allowing the refrigerant or heating medium to flow through metal pipes and exchanging heat with the air outside the pipes, it achieves air cooling, heating, or temperature and humidity regulation. The specific process is as follows:

Heat Transfer: There is a temperature difference between the refrigerant (such as chilled water, refrigerant, etc.) or heat transfer medium circulating within the surface cooler and the external air. As air flows through the outer wall of the pipes of the surface cooler, heat is transferred from the air with a higher temperature to the medium within the pipes with a lower temperature (in the cooling mode) or from the medium within the pipes to the air (in the heating mode), thus enabling the exchange of heat.

Wet exchange process: During cooling, if the surface temperature of the surface cooler is lower than the dew point temperature of the air, the water vapor in the air will condense onto the surface of the pipes, forming a liquid water film. This process involves not only sensible heat exchange (temperature change) but also latent heat exchange (water vapor condensation and release or absorption of heat), thereby enabling the dehumidification of the air. If the surface temperature of the surface cooler exceeds the air’s dew point temperature, only isothermal cooling or heating occurs, and the humidity of the air remains unchanged.

Enhanced heat exchange measures: To improve heat exchange efficiency, surface condensers typically employ finned tube structures, which increase the contact area between the pipes and the air, while also promoting air turbulence and reducing thermal resistance. Some surface condensers are also equipped with fans to force airflow, further enhancing the heat exchange effect.

In summary, by precisely controlling the temperature of the refrigerant/heat transfer medium, airflow, and surface temperature, the air cooler achieves precise regulation of air temperature and humidity, and is widely used in air conditioning, industrial cooling, and dehumidification applications.