Condensers (If we are talking about cooling down a fluid) or heat exchangers
(If we are talking in general) are essential part of any industry. Due to these pieces of equipment, the transfer of heat takes. In a refrigeration process
, condensers are used to cool down the refrigerant. But in different machineries they can be doing heating work also and there they are called as heat exchangers. For instance, Lube cooler associated with main engine is called as ‘heat exchangers’. As such there is no difference between these two terms and can be used as per the suitability of work. During cooling down, refrigerant gives off its heat to the cooling medium. And then it is send towards the throttling valve for getting cooling effect from the refrigerant. Now these condensers are of many types and I have discussed about them in brief details. If you want read more about refrigeration, go to this page
Condensers Working and Condensers Uses
What are condensers and their types? Well I have given you the definition of a condenser, but now come the question, which among them is mostly used onboard ship. Well, Shell and tube type of condensers are mostly used on ship. Below diagram gives you the perfect details about the components. But there are other type of Condensers like plate type, plate and tube type etc.
On ships ‘Shell and Tube’ type are the common one and designed to operate at high pressures. The fluid that has to be cool down flows
outside the tubes, and the fluid that will take heat away is flown through inside of tubes. Generally we have a two pass arrangement system in a condenser. This guarantees that heat transfer from one medium to another medium is quick and good. Generally sea water is used as a cooling medium and being in abundance it mostly preferred on every ship. But nowadays since central cooling system is becoming more famous, cooling through fresh water is making way in to this industry. To prevent metal tubes being eroded by the sea water, we keep its velocity to around 2.5 m per second. For preventing corrosion of metal parts in a condenser, sacrificial anodes are used to prevent them. Sacrificial anode degrades themselves
. And hence whole metal structure is prevented from getting damaged by the sea water. For long life of tubes that are being used in these equipment are being made from metal like cupronickel, brass tubes etc.
Problems and troubleshooting in Condensers
There are several types of problems that occur in a refrigeration system. Air being most undesirable in a refrigeration system and it has to be taken care of. Most important problem with air is that it in in compressible. And tends to attract moisture and water condensation stakes place. This causes damages to the compressors and the pipeline of the refrigeration system. There are separate valves provided to remove air occurring in the system. During air removal whole refrigerant is collected in the receiver or condensers and then these valves are opened. Air being light as compared to refrigerant, goes up and leaves the system.
Another problem related with the condenser system is that, refrigerant tends to leak at certain places. This leads to overall decreases in the pressure. So tubes of condensers should be checked for leakages. Due to flow of sea water in these tubes, scale starts forming inside these tubes. Due to this heat transfer does not take place and results in localized heating and can result in disastrous results if not rectified on time. On regular intervals, the tubes are cleaned manually. Special care has to be taken while charging the compressors of a refrigeration system.