Air cooled heat exchangers are only one of many forms of heat exchanger. Heat exchangers are gadgets which are particularly designed for aiding the transfer of heat from one fluid towards the other. And for us to better fully grasp, typical samples of appliances which use heat exchangers would be the air conditioners, fridges as well as space heaters.
But let's not dwell too much on the general heat exchanger instead let's at this point look at air cooled heat exchangers or ACHEs for short. This rejects heat from a warm fluid directly to fan-blowing ambient air. ACHEs are generally utilized whenever a procedure or set up produces heat that have to be removed and regrettably does not have local use. The automobile radiator is an example of ACHE equipment. The motor needs to be cooled down to avoid overheating due to friction and combustion functions of the engine. The extra heat is carried away by the water or glycol coolant mix. Majority of the heat have to be dispersed, and the best way is by supplying ambient air.
There are more uses of air cooled heat exchangers, like the upstream production, refineries and petro-chemical facilities. It can also be employed on situations with high temperature, high pressure, corrosive fluids and environments. Moreover, air coolers may be equipped and utilized in gas and oil refineries; compressor stations for gas pipelines; subsurface gas storage facilities; plants producing polychlorvinyl, polyethylene, glass fiber, biplastic; caustic soda plants; by-product coke plants and ammonia transportation and handling plants.
In addition to being aware of the actual functions of ACHEs, we should also have a view upon how it works inside and its components. Generally, air coolers for process usage are comprised of a finned-tube bundle with rectangular container headers in both ends of the tubes. Headers are boxers that eliminates the fluid in the piping to the tubes. The other parts include a number of fans that provide cooling air. The fans are commonly driven by electrical motors and are supported by speed reduction devices. The fan drive assemblage is sustained by a metal mechanical drive support system. Normally, the air flows up-wards all the way through a horizontal tube bundle. The fans could be either forced or induced draft, dependant upon if the air is pushed or pulled through the tube bundle. Forced draft unit permits a straightforward access for maintenance for the fans and to the bundles. In addition, the fans continue to be within the cold ambient air. Whilst the induced draft unit o!
ffers a steady as well as strong thermal performance due to the protection of the finned surface against wind, rain, hail and snow by the plenum chamber. The induced draft also assures a better air distribution, less hot air recirculation, less air-side fouling and reduced noise levels at grade. Space in between the fans and the tube bundle is encircled by a plenum chamber, that directs the air. The entire assembly is generally installed on legs or a pipe rack.
Understanding and knowing the inside and out of ACHEs is fairly hard, particularly when you have no background in mechanical matters. And due to this, let us once more shift our focus on another subject matter, which is the "why" question. With regards to economy, air coolers are desired due to lower maintenance cost. Some other benefits presented by air coolers are as follows: lack of the need for cooling water or other cooling media, no problem shall arise with regards to the thermal and chemical pollution of cooling fluids, and it quite fast to install by bolted assembly.
ACHEs are also considered as a "green" alternative because no chemical treatment is needed to the water or fluid used by the assembly. And temperature is the only parameter that needs to be considered when getting rid of the water used. Without a proper heat exchanger equipment, overheating can certainly ruin your equipments and appliances, specially the parts subjected to heat. Out of all the things which have been mentioned, if we're to think about the trend the world is going, air cooled heat exchangers are the best choice for industrial plants and other plants when the environment is to be considered.