Working Principle of Steam Condenser

Working Principle of Steam Condenser

The working principle of a steam condenser is mainly to transfer the heat in the steam to the cooling medium, so that the steam is cooled and condensed into liquid.

There are various types of common steam condensers, and the working principle of different types of condensers varies slightly:

Water-cooled condenser: Water is used as the cooling medium. For example, horizontal shell and tube condenser, the refrigerant vapour condenses inside the shell and tube, and the cooling water flows outside the tube to take away the heat released when the refrigerant condenses. There are also casing condenser, which consists of different diameters of the tube set together and bent into a spiral or serpentine, refrigerant vapour condensation between the casing, cooling water in the diameter of the pipeline flow, and the refrigerant to form a countercurrent, thus enhancing the effect of heat transfer.

Spray condenser: Cold water is sprayed in from the upper nozzle, and steam enters from the side entrance. The steam is condensed into water after full contact with cold water, and at the same time flows down the tube, and part of the non-condensable vapour may also be taken out.

Filled tower condenser: The upper part of the tower is equipped with a porous plate liquid distribution plate, and the tower is filled with Lacy ring packing. The contact between cooling water and vapour on the surface of the packing improves the condensation effect, and is suitable for the case of large amount of secondary vapour and condensation of corrosive gases.

Air-cooled condenser: with air as the cooling medium, the refrigerant condenses inside the tube, and the air flows outside the tube to absorb the heat released by the refrigerant vapour inside the tube. Due to the small heat transfer coefficient of air, the tube is often set outside the rib to strengthen the heat transfer. Among them, the air-cooled condenser with free flow of air makes use of the change of air density to achieve natural convection heat transfer; while the air-cooled condenser with forced flow of air prompts the air flow through the fan and so on.

Evaporative condenser: the use of water evaporation to absorb heat to make the tube refrigerant vapour condensation. The water is lifted by the pump and then sprayed by the nozzle to form a water film on the outer surface of the heat transfer tube, part of the water absorbs heat and evaporates into water vapour, which is then taken away by the air entering the condenser, and the un-evaporated water droplets fall into the lower pool.

Take the common water-cooled condenser as an example, its working process is roughly as follows: steam enters the condenser from the inlet, and comes into contact with the cooling water tubes or other cooling structures inside the condenser. The cooling medium (usually water) flows continuously through these cooling structures, absorbing heat from the steam and gradually cooling it. As the temperature decreases, the vapour reaches saturation and begins to condense into a liquid, releasing latent heat. The condensed liquid is discharged from the condenser by gravity or other means, while the cooling medium continues to circulate, carrying away the absorbed heat to maintain a continuous cooling effect.

In the working process of steam condenser, in order to improve the efficiency, some measures are usually taken, such as increasing the heat exchange area, increasing the flow rate of the cooling medium, and improving the characteristics of the heat exchange surface. At the same time, the design and selection of the condenser need to take into account a variety of factors, such as the flow rate, temperature and pressure of the steam, the type and availability of the cooling medium, as well as the installation space, cost and so on. Different types of steam condensers have their own characteristics and applicable scenarios, and need to be selected and designed according to specific needs in actual applications.