Condensers are a familiar type of power equipment. Today, I'd like to discuss their types and components with you, hoping to provide some assistance to new customers! Condensers can be divided into two categories based on the method of steam condensation: surface-type (also known as shell-and-tube) and mixed-type (also known as contact-type). In surface-type condensers, steam separated from the cooling medium is condensed into a liquid on the cooling wall surface (usually metal tubes). The cooling medium can be water or air. Water-cooled surface-type condensers are divided into single-pass and double-pass types based on the flow of cooling water. In mixed-type condensers, steam is condensed into a liquid while mixed with the cooling medium. The condensed steam can be water vapor or vapor of other substances.
The condenser is mainly composed of the shell, tube bundle, hot well, and water chamber. The exhaust steam from the steam turbine enters the shell through the throat, condenses into water on the cooling tube bundle, and collects in the hot well, where it is then pumped out by the condensate pump. Cooling water, also known as recirculating water, enters the cooling tube bundle from the inlet water chamber and exits from the outlet water chamber. To maintain a high vacuum and excellent heat transfer efficiency within the condenser during steam condensation, an exhaust equipment is provided, which continuously extracts air and other non-condensable gases that leak into the condenser. The exhaust equipment includes water-jet vacuum ejectors, steam-jet vacuum ejectors, mechanical vacuum pumps, and combined vacuum pumps.
Air flows laterally through the tubes on the outer side of the air-cooled surface condenser, either with the help of a fan or through natural ventilation, while steam flows inside the tubes and condenses into water. To enhance heat transfer outside the tubes, these condensers are equipped with externally finned tubes. They have a much higher back pressure compared to water-cooled condensers.
Mixed-type condensers come in two types: spray-type and flat jet-type. In the spray-type condenser, cooling water is atomized into droplets; while in the flat jet-type, cooling water contacts the exhaust steam of the turbine in a film-like state. Generally, the flat jet-type structure is more commonly used due to its higher vacuum level, which can exhaust all non-condensable gases completely.