I just bought a soldered plate heat exchanger so I can run my hot glycol from my woodstove to a heat exchanger to heat hot water before letting the cooled but still warm glycol to go and heat up my in floor heating pumps. I am going to see if I can use natural convection the whole way through with no circulating pumps. Your explanations are very helpful! Luckily the brazed ones are fairly cheap so I will just plumb in another one if I need more hot water
Our department got some heat exchanger models several decades ago from companies making heat exchangers. I don't think there is anyone making them today. If you want one, my best bet is that you talk with someone who is good at designing CAD models for 3D-printing and create your own. Once you have an STL file that has been checked for errors, try to print one and see if it works. You're the second guy asking the same question (the first question was sent to me privately) so if there is someone out there who is good at CAD-designs and want to help students understand heat exchange, I'm thinking that a CAD model declared as public domain would be very helpful to many teachers and students.
That's a rather advanced question well outside the boundaries of the courses I teach and unfortunately also outside my area of expertise. I can say this much though: In basic courses we often teach students that heat transfer coefficients has everything to do with the moving fluidum and nothing to do with the solid construction it flows past (apart from the hydraulic diameter of the passage, that we enter when calculating Reynolds number). That is, however, a simplification. While the material the solid construction is made of, the surface structure does influence. For the student who have learnt about pressure drop in pipes and how the courseness of the surface is important for reading the fanning friction factor from diagrams, it should be clear that the surface structure affects the transport of momentum in the moving liquid. But if the surface structure affects the transport of momentum, it should also affect heat transfer (compare Chilton-Colburns analogy and Reynolds analogy). A plate fin offset heat exchanger is a compact, effective heat exchanger. Now, if you reduce the size of a heat exchanger without changing the general design the problem is that Reynolds number gets smaller (smaller hydraulic diameter => smaller Re => less turbulent & more laminar => lower heat transfer coefficent. By constructing the flow paths in a way that the flow is constantly distrubed, the flow constantly meeting new edges and bends, you get less laminar flow and thus higher heat transfer coefficients.
I just bought a soldered plate heat exchanger so I can run my hot glycol from my woodstove to a heat exchanger to heat hot water before letting the cooled but still warm glycol to go and heat up my in floor heating pumps. I am going to see if I can use natural convection the whole way through with no circulating pumps. Your explanations are very helpful! Luckily the brazed ones are fairly cheap so I will just plumb in another one if I need more hot water
I just bought a soldered plate heat exchanger so I can run my hot glycol from my woodstove to a heat exchanger to heat hot water before letting the cooled but still warm glycol to go and heat up my in floor heating pumps. I am going to see if I can use natural convection the whole way through with no circulating pumps. Your explanations are very helpful! Luckily the brazed ones are fairly cheap so I will just plumb in another one if I need more hot water
Teacher, your explain is incredible!!! Thanks from Puebla city in Mexico
Thank you very much.
I am Korean.
It was a great help.
Great visual explanation Sir. thanks a ton. keep posting
Thank you so much for posting this sir! Huge help.
Amazing explanation sir! Thanks!
thank you so much for your helpfull lessons
Thank you, Sir
thanks a lot, amazing explanation
Thank you!
Amazing explanation.
Thank you!
Where did you get the spiral model?
Our department got some heat exchanger models several decades ago from companies making heat exchangers. I don't think there is anyone making them today. If you want one, my best bet is that you talk with someone who is good at designing CAD models for 3D-printing and create your own. Once you have an STL file that has been checked for errors, try to print one and see if it works.
You're the second guy asking the same question (the first question was sent to me privately) so if there is someone out there who is good at CAD-designs and want to help students understand heat exchange, I'm thinking that a CAD model declared as public domain would be very helpful to many teachers and students.
Please,l need to explain about plate fin offset strip type
That's a rather advanced question well outside the boundaries of the courses I teach and unfortunately also outside my area of expertise. I can say this much though:
In basic courses we often teach students that heat transfer coefficients has everything to do with the moving fluidum and nothing to do with the solid construction it flows past (apart from the hydraulic diameter of the passage, that we enter when calculating Reynolds number). That is, however, a simplification. While the material the solid construction is made of, the surface structure does influence. For the student who have learnt about pressure drop in pipes and how the courseness of the surface is important for reading the fanning friction factor from diagrams, it should be clear that the surface structure affects the transport of momentum in the moving liquid. But if the surface structure affects the transport of momentum, it should also affect heat transfer (compare Chilton-Colburns analogy and Reynolds analogy).
A plate fin offset heat exchanger is a compact, effective heat exchanger. Now, if you reduce the size of a heat exchanger without changing the general design the problem is that Reynolds number gets smaller (smaller hydraulic diameter => smaller Re => less turbulent & more laminar => lower heat transfer coefficent. By constructing the flow paths in a way that the flow is constantly distrubed, the flow constantly meeting new edges and bends, you get less laminar flow and thus higher heat transfer coefficients.
I just bought a soldered plate heat exchanger so I can run my hot glycol from my woodstove to a heat exchanger to heat hot water before letting the cooled but still warm glycol to go and heat up my in floor heating pumps. I am going to see if I can use natural convection the whole way through with no circulating pumps. Your explanations are very helpful! Luckily the brazed ones are fairly cheap so I will just plumb in another one if I need more hot water