Counterflow double pipe heat exchanger

[cabellos2]

Im just generally reading through the notes for thermal design for a counterflow double pipe heat exchanger.

Is it possible for all temperatures inlets and outlets to be different for this type of flow arrangement?

What is confusing me is the temperature profile graph where Th2 appears to be the same temperature as Tc1?

 

[ank_gl]

Is it possible for all temperatures inlets and outlets to be different for this type of flow arrangement?

Yes it is possible. Inlet temperatures for both hot & cold streams depend upon the source(pretty much defined by the problem itself), the outlet temperatures depends on the effectiveness of the unit, which depends on the thermo physical properties properties of fluid, wetted surface area & overall heat transfer coefficient.

What is confusing me is the temperature profile graph where Th2 appears to be the same temperature as Tc1?

A case when effectiveness of the exchanger is 100%.

 

[oswaler]

I can clarify that it is indeed possible for all temperature inlets and outlets to be different in a counterflow double pipe heat exchanger. This flow arrangement allows for the hottest fluid to enter the heat exchanger at one end and the coldest fluid to enter at the other end, creating a counterflow effect. This results in a more efficient heat transfer compared to other flow arrangements.

Regarding the confusing temperature profile graph, it is important to note that Th2 and Tc1 refer to the temperatures at the inlets of the hot and cold fluids respectively. As the fluids flow through the heat exchanger, their temperatures will change due to the heat transfer process. Therefore, the temperatures at the outlets of the hot and cold fluids, Th1 and Tc2, may not necessarily be the same as Th2 and Tc1. The temperature profile graph shows the change in temperature along the length of the heat exchanger, not just at the inlets and outlets. I hope this clarifies any confusion.