stuartsjg
Electrical
- Sep 25, 2009
- 1
Hi, i have a specification of a plate heat exchanger as follows:
Side 1 Side 2
In 80C 5C
Out 35.3C 41.2C
Flow 25L/min 30L/min
Power 75.9kW
Fluids are water.
What im trying to do is work out what would happen, if i had say 20L/min in side 2.
My initial thought was that the side 2 out would increase its temperature proportionality, but on further thinking this wont be the case. The LMTD would fall causing less heat transfer, the power will reduce... and so it goes on.
I tried to make a spreadsheet which worked out the existing LMTD of the above example, then determine a kW/K constant for the exchanger, but that didnt work either.
Is there any spreadsheet, freeware software, rule of thumb etc. which would allow me to convert the known example above into a model of the heat exchanger so that i can input a new, say, side 2 flow rate and it would determine the resultant side one and 2 output temperatures.
The application is a thermal store for my house to deliver mains pressure hot water via a heat exchanger.
Thanks,
Stuart
Side 1 Side 2
In 80C 5C
Out 35.3C 41.2C
Flow 25L/min 30L/min
Power 75.9kW
Fluids are water.
What im trying to do is work out what would happen, if i had say 20L/min in side 2.
My initial thought was that the side 2 out would increase its temperature proportionality, but on further thinking this wont be the case. The LMTD would fall causing less heat transfer, the power will reduce... and so it goes on.
I tried to make a spreadsheet which worked out the existing LMTD of the above example, then determine a kW/K constant for the exchanger, but that didnt work either.
Is there any spreadsheet, freeware software, rule of thumb etc. which would allow me to convert the known example above into a model of the heat exchanger so that i can input a new, say, side 2 flow rate and it would determine the resultant side one and 2 output temperatures.
The application is a thermal store for my house to deliver mains pressure hot water via a heat exchanger.
Thanks,
Stuart
