Plate heat exchanger issues
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I have a rather modest question: in a heat exchange system that uses plate heat exchangers, after the design, selection, and installation are complete, what would happen if I doubled the surface area of the heat exchangers? Without considering cost factors, I just want to know whether the heat exchange capacity of this plate heat exchanger system would increase or decrease. Why?
"The “square meters of the heat exchanger” should refer to the “heat exchange area of the heat exchanger”. If it is doubled, and if the inlet flow rates and temperatures of the cold and hot fluids remain the same as before, the heat exchange efficiency generally increases, unless the original heat exchanger already has very good heat exchange performance. But it generally does not increase to twice the original amount. The above are my personal opinions.
The original heat exchanger has an excellent heat exchange efficiency. What would happen if the surface area of the heat exchanger were doubled or multiplied by several times? I just want to know whether the heat exchange capacity of this plate heat exchanger increases or decreases. Why? :$ :$ :$
Of course, an increased heat exchange area leads to an enhanced heat exchange capacity.
Of course, it increases heat exchange. Why? Because you have increased the heat exchange area. In the limit, the temperatures of the two media are in equilibrium.
Increasing the heat exchange area reduces the flow velocity inside the plate exchanger, resulting in less turbulence and a lower surface heat transfer coefficient.
As the heat exchange area increases, the average temperature difference for heat exchange decreases, which means that more thermal energy can be recovered. Theoretically, by increasing the area to infinity, the heat load can be fully recovered, but simply enlarging the heat exchange area is not necessarily cost-effective.
The effect increases because, with all other conditions remaining unchanged, an increase in area inevitably leads to an increase in effect.
The performance of the original heat exchanger is already roughly the same as that specified in the original design. If its area is doubled while the flow rate remains unchanged, the flow velocity through the heat exchanger will be halved, which will certainly lead to a decrease in its heat exchange efficiency. However, over time, dirt accumulation on the original heat exchanger will reduce its heat exchange capacity; installing a new heat exchanger will help improve this capacity. In such cases, it is generally possible to use one unit while keeping another as a backup. When the heat exchange efficiency of the original heat exchanger drops significantly, the backup unit can be used to carry out repairs on the original one.
It’s not the case that the greater the heat exchange area, the better.