Article Contents
Countercurrent heat exchanger:- A heat exchanger is nothing but mechanical equipment which used to transfer the heat from hot fluid to cold fluid.
Hi friends welcome to chemical engineering guides. Todays article covers basic to little advance level information about counter current flow heat exchanger. As we know that in heat exchanger we can arrange the fluid flows in three (or some time 4 ) ways.Or we can say there three types of fluid flow ( hot fluid and cold fluid) arrangements in the heat transfer equipment. The main three fluids arrangements are as follows,
- Counter current flow
- co current flow ( parallel flow)
- cross flow
countercurrent heat exchanger
As per her name counter ( opposite to each other or against of each other) the flow arrangement in counter current flow type heat transfer equipment is opposite to each other. In counter flow exchanger one fluid ( may be hot or cold fluid) enter at one side of the heat transfer equipment and second fluid ( hot or cold depends upon selection as per process) enter at the other end of heat transfer equipment. This why arrangement is look like counter to each other.
what mean countercurrent heat exchanger ?
A counter current heat exchanger is nothing but a heat exchanger in which hot fluid and cold fluid flow in opposite direction to each other in a typical heat exchanger.
Example of countercurrent heat exchanger
Now we study the example of a typical counter current types of heat exchanger.
As shown in following figure, hot Fluid enter at place ” A “at 80 degree Celsius and get cool to 50 degree Celsius. And cold fluid enter at “B” at 30 degree Celsius temperature and leave the heat exchanger at “B” having temperature 40 degree Celsius. So flow direction of hot fluid is from “A” to “B” and flow direction of cold fluid is from “B” to “A”, so this is example of countercurrent flow in a shell and tube type of heat exchanger.
why counter current flow heat exchanger is better than co current flow heat transfer equipment?.
In countercurrent heat exchanger we get the high efficiency because of uniform heat transfer occurred, so counter current flow heat exchanger is better than parallel or co current flow heat transfer equipment.
LMTD for countercurrent heat exchanger
LMTD is nothing but logarithmic mean temperature difference. Following formula is applicable for LMTD calculation in case of counter current flow heat exchanger.
co current flow heat exchanger
In co current flow heat exchanger both (cold and warm) fluids enter the heat exchanger at same end leave at same end of heat exchanger. As like counter current flow heat exchanger co current or parallel flow heat exchanger not gives the efficiency.
Conclusions
A heat exchanger is mechanical equipment or device which use to exchange the heat in between hot and cold fluid depends on the process requirement. We arrange the flow direction of hot and cold fluid in three ways. First one is counter current flow ( which is use in countercurrent heat exchanger), second one is co current flow or parallel flow and third one is cross flow. In counter current flow one fluid (either hot or cold) inters at one end of heat exchanger and travel towards other end of heat transfer equipment, second fluid (cold or hot or warm ) enter at the another end of equipment and flow towards opposite end of equipment. Countercurrent heat exchanger always gives the good efficiency as compared to other two types of heat exchanger. Example of countercurrent current heat exchanger clear the all concept regarding counter current heatexchanger.
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