Can this be done with a heat exchanger?

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SUMMARY

The discussion centers on the feasibility of using a plate heat exchanger with differing flow rates on the primary and secondary sides while maintaining the same temperature differential (Delta T). Participants confirm that conservation of energy dictates that flow rates must be equal when Delta T is identical. The close temperature values (12/16°C on the primary side and 14/18°C on the secondary side) imply that specific heat remains constant, reinforcing the impossibility of differing flow rates under these conditions. Suggestions for explaining this concept to clients emphasize the importance of energy conservation and specific heat capacities.

PREREQUISITES
  • Understanding of heat exchanger principles
  • Knowledge of Delta T and its significance in thermal systems
  • Familiarity with specific heat capacity concepts
  • Basic principles of energy conservation in thermodynamics
NEXT STEPS
  • Research the principles of plate heat exchangers
  • Learn about the impact of specific heat capacity on thermal efficiency
  • Explore energy conservation laws in thermodynamic systems
  • Investigate how varying flow rates affect heat transfer in different fluids
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Mechanical engineers, thermal system designers, and contractors involved in HVAC and heat exchange applications will benefit from this discussion.

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A customer of mine came to me asking for a price on a plate heat exchanger for water. The data he brought me was the following:

Primary side: 1,9 l/s and 12/16 C.
Sec. side: 2,4 l/s and 14/18 C.

I was just wondering if it is even possible to have different flows when the delta T is the same on both sides...?
 
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No, conservation of energy requires that they be the same.
 
Thx, good to get that confirmed. Any tips on how I can easily explain this to him so that he "gets it" ?
 
If the temperatures of the fluid were drastically different it would be possible for different flowrates to give identical drops in temperature as specific heat is temperature variant. However, in this case the temperatures are so close that specific heat is in effect constant.
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http://www.cfdengineer.com.
 
Is it the same liquid on each side? If the specific heat capacities are different you might get the same Delta T with different flow rates.
 
I agree with doc.

I am not an engineer, just a Mechanical contractor. The Delta T's you listed are so close, they are in effect the same. If the fluids were different, then maybe. But you deltas are so close...
 

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