What is the function and principle of a condenser?

Condensers are primarily used in steam turbines and chemical production processes. When used with a turbine, a condenser not only condenses the turbine’s exhaust steam into water for reuse in the boiler, but it also creates a vacuum at the turbine’s exhaust site that is much lower than atmospheric pressure, thereby **increasing the turbine’s output power and thermal efficiency. 　　Over time, deposits form within the tubes of a condenser, **which affects the heat exchange efficiency and leads to significant energy waste. It is therefore necessary to clean these tubes. The most convenient and practical method for cleaning them at present is the condenser scraper cleaning technique; water accumulated in the tubes provides the power needed to drive a scraper head, which rotates through the tubes to carry out the cleaning process ； 　　Technical features of the condenser blade cleaning technique: 1. Fast: Two people can carry out the cleaning operation simultaneously, allowing 1,000 condenser tubes to be cleaned per hour. During cleaning, the primary and secondary sides can be cleaned alternately without shutting down the machine, **reducing the maintenance time for the condenser. It is particularly suitable for emergency cleaning while the power plant is operating under partial load during summer, when the vacuum of the condenser is poor; cleaning can be carried out without shutting down the plant (cleaning can be done without removing the end covers if there are manholes on the condenser). 　　2. Safety: Made of special polyethylene – safe and does not damage the pipes or the flanges on the pipe sheets. It is particularly suitable for cleaning the thin-walled copper and titanium tubes in power plant condensers. 　　3. High efficiency: Generally, cleaning a bullet is completed in just one pass through the pipeline. For pipelines with heavy dirt buildup or during the first cleaning, the process can be repeated once. For those pipes that are blocked by sediment and no light from the other side can be seen, it is necessary to fire a blank shot before carrying out the cleaning. One cleaning session yields noticeable results. After multiple washes, the end difference is significantly reduced, greatly improving the efficiency of the unit. 　　4. Easy to inspect: Cleaning removes all the dirt from the condenser pipes, resulting in significant cleaning effects; it’s also very easy to see the results of the cleaning. 　　5. Low cost: The cleaning cost is only 1/2 of that of high-pressure water jet cleaning.

The main functions of the condenser are as follows: 1) To create a high vacuum at the turbine exhaust outlet, allowing the steam to expand to the lowest pressure within the turbine, thereby increasing the available enthalpy drop of the steam in the turbine and improving the thermal efficiency of the cycle； 2) Condense the exhaust steam from the turbine into water, which is then sent back to the boiler for recycling ； 3) Gather various hydrophobes to reduce steam loss. The working principle of a surface condenser is as follows: it contains a large number of copper tubes through which circulating cooling water flows. When the steam discharged from the turbine comes into contact with the outer surface of the copper tubes in the condenser, it is cooled by the water flowing inside the tubes; as a result, its latent heat of vaporization is released and it turns into condensed water. This latent heat is continuously transferred through the wall of the copper tubes to the circulating cooling water, where it is carried away. In this way, the exhaust steam is continuously condensed through the condenser. When the exhaust steam is cooled, its specific volume decreases sharply; as a result, a higher vacuum is created inside the condenser at the turbine exhaust outlet.

The condensing equipment of a condensing steam turbine typically consists of a surface condenser, exhaust extraction devices, a condensate pump, a circulating water pump, as well as the piping that connects these components together. The exhaust gas leaves the turbine and enters the condenser, where cooling fluid supplied by the circulating water pump flows in to condense the turbine’s waste steam into water. As the steam turns into water, its volume decreases sharply, thereby creating a vacuum in the enclosed space of the condenser that was previously filled with steam. To maintain this vacuum, exhaust extractors continuously remove air that leaks into the condenser, preventing non-condensable gases from accumulating there and causing the pressure inside the condenser to rise. The condensate collected at the bottom of the condenser is then sent via the condensate pump to the deaerator to be used as boiler feedwater. Thus, the functions of the condensing equipment are: (1) to create and maintain a high vacuum at the turbine’s exhaust outlet; (2) to condense the turbine’s exhaust gas into clean condensate water for reuse as boiler feedwater. In simple terms, the role of the condenser is to convert waste steam into water.

After leaving the turbine, the exhaust gas enters the condenser, where a cooling fluid supplied by the circulation pump flows in to condense the turbine’s waste steam into water. As the steam turns into water, its volume decreases sharply, thereby creating a vacuum in the enclosed space of the condenser that was previously filled with steam. To maintain this vacuum, an extractor continuously removes any air that leaks into the condenser, preventing non-condensable gases from accumulating there and causing the pressure inside the condenser to rise. The condensed water collected at the bottom of the condenser is then sent to the deaerator via the condensation pump to be used as boiler feedwater. (1) A high vacuum is established and maintained at the turbine’s exhaust outlet; (2) The turbine’s exhaust gas is condensed into clean condensed water, which is reused as boiler feedwater. The formation of vacuum in the condenser is mainly due to the fact that the turbine’s exhaust gas is cooled into condensed water, resulting in a sharp decrease in its specific volume. For example, at an absolute pressure of 4 kPa, the volume of steam is 30,000 times larger than that of water; when the steam condenses into water, its volume decreases significantly, thereby creating a high vacuum inside the condenser. Three conditions must be met for the formation and maintenance of vacuum in the condenser: 1) The copper tubes of the condenser must be cooled by a sufficient amount of water ； 2) The condensate pump must continuously remove the condensate to prevent the water level from rising, which could affect steam condensation ； 3) The extraction pump must remove the air that has leaked in as well as other gases present in the exhaust steam.