# Mechanical Engineering - Heat Transfer, Refrigeration and Air Conditioning - Discussion

4.

In counter-current flow heat exchangers

 [A]. both the fluids at inlet are in their hottest state [B]. both the fluids at inlet are in their coldest state [C]. both the fluids at exit are in their hottest state [D]. one fluid is coldest and the other is hottest at inlet

Explanation:

No answer description available for this question.

 Sanosh said: (Apr 11, 2015) No, the answer is D. If both the fluids at inlet are in their hottest state, then what is the use of heat exchanger. In counterflow, 1 fluid enters in coldest state and leaves hotter while another fluid enters hottest and leaves colder after transferring heat to the counter fluid.

 Hemanta said: (Jun 10, 2016) The answer should be option D.

 Jaydeep said: (Sep 27, 2016) I think the answer should be option D.

 Wael said: (Oct 4, 2016) The correct answer is D.

 Gopal Dey said: (Nov 1, 2016) This answer is definitely wrong. The correct one is D.

 Ming H. said: (Dec 10, 2016) Yes. The Answer Should Be "D".

 Vikas Singh said: (Feb 17, 2017) Yes, D is the correct one.

 Nithin John Simon said: (Mar 17, 2017) D is the correct answer. How option A is possible?

 Syed said: (Mar 19, 2017) I think the answer should be D.

 Nikky said: (Jul 15, 2017) No answer is right. The main concept of the given question was, inlet means at the inlet of the heat exchanger. Not separate inlets of hot and cold fluids. Hot fluid is flowing from left to right and cold fluid is flowing from right to left. Then the given answer should be right.

 Ravi said: (Jul 22, 2017) Yes, Correct @Nikky.

 Yasin said: (Nov 17, 2017) What do mean the inlet of heat exchanger? inlet of fluid is called inlet.

 Kedar said: (Oct 6, 2018) @Yasin consider the following. 1. Hot fluid enters from left. 2. Cold fluid enters from the right. (since it is counter flow HE both fluids will enter in opposite direction i.e. left and right respectively. 3. Hot fluid will become cold and leaves from the outlet. 4. Cold fluid gets hotter and leaves from left. Now consider 1 & 4, both fluids at the inlet are hot.

 Ravi said: (Mar 15, 2019) Both the hot and cold fluid has separate inlet then why we just count the inlet of the hot fluid side?

 Zalak said: (May 14, 2019) Thanks you @Kedar.

 Pratipalsinh Zala said: (Jul 17, 2019) The right answer is D. I too agree.

 Martin said: (Sep 24, 2019) Right, Thanks @Kedar.

 Kkh said: (Oct 23, 2019) @Kedar it's an outlet for the cold we can't consider inlet for both.

 Noor said: (Aug 10, 2020) No @Kedar. Option D is the right option.

 Vinay said: (Nov 6, 2020) Both the fluids at inlet are in their hottest state.