Water flow rate in the heat exchanger
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In the heat exchanger, the water flows through the shell side. The water pump has a capacity of 100 liters per hour and a head of 56 meters; the pump outlet diameter changes from 65 to 150, and before reaching the heat exchanger it further changes to 50 before entering the heat exchanger. What is the flow rate of water in the heat exchanger? The heat exchanger has a diameter of 400 and a length of 2 meters. Can it be distributed evenly to each heat exchanger at 25 cubic meters per hour? I hope experienced folks can offer some guidance.
The flow rate of water in a typical heat exchanger is around 1.5 m/s; it also depends on the characteristic curve of the pump used and the pressure of the water at the outlet. Therefore, theoretical calculations can only serve as a reference – actual measurement is necessary to determine the precise value
Whether it is possible to distribute the flow evenly among each heat exchanger depends on your flow distribution method. I assume you are using a conventional distribution method, which results in uneven distribution; therefore, it is necessary to employ some methods for flow distribution.
Estimate it by dividing the flow rate by the flow area :)
In the heat exchanger discussed by the original poster, the flow velocity of the fluid on the shell side is related to the structure of that side; both the spacing between the baffle plates and the height of the notches in those plates affect the flow velocity on the shell side. I wasn’t clear on what you said earlier; to calculate the flow rate, all that’s needed is the water flow rate entering the heat exchanger and the heat exchange area on the shell side of the exchanger. Because the density of liquids is generally independent of pressure; however, the flow rate of water is taken to be around 1 m/s
Basically, it can be distributed evenly; as long as the structure is not severely asymmetric, there is no need to worry about traffic distribution. The flow velocity inside the heat exchanger is related to the number of tubes, the spacing between baffle plates, and the area of the notches on the baffle plates; the given parameters are insufficient. The flow rate of water in general heat exchangers is between 1.2 and 1.8 m/s. For shell-and-tube heat exchangers, the flow rate in the shell side should be slightly lower, typically around 1 m/s. If it is necessary to increase the flow rate due to structural constraints, the resistance in the shell side must be checked.
For 100 cubic meters, if the four heat exchangers are identical, the volume can be distributed equally. As for the flow velocity within the heat exchangers, it depends on factors such as the number of heat exchange tubes, the spacing between baffle plates, the diameter of the shell, and the specifications of the heat exchange tubes.
I disagree with your view; it’s possible to achieve uniformity without having to consider traffic distribution? You can try simulating it using CFD tools, but it’s simply impossible! Have you done the test? Don’t draw conclusions so hastily; it is suggested that the original poster draw a diagram of the traffic distribution device, so we can analyze it. If you simply use a tee to distribute it, the distribution will definitely be uneven; so don’t even think about ignoring the distribution issue!