Recently, a customer asked our customer service how the average temperature difference method of the plate heat exchanger
can be calculated. Today I will explain it to everyone!
1. Calculate the unknown temperature or flow rate, calculate the unknown temperature or flow rate through the heat balance equation, and also calculate the heat load Q.
2. Select the appropriate plate type, and select the appropriate plate type according to the heat exchange capacity and flow rate.
The choice of plate model depends on the specific working conditions. When the flow is large and the pressure drop is low, a plate with a small resistance should be selected; otherwise, a plate with a larger resistance coefficient can be used.
3. Estimate the heat exchange area and calculate the approximate heat exchange area based on the heat exchange amount.
4. Select the process and the number of channels, and initially select the number of cold and hot fluid processes and the number of channels, and calculate the flow rate from it.
5. Find the average temperature difference.
6. Find the convective heat transfer coefficient and the total heat transfer coefficient. First, find the convective heat transfer coefficients of the cold and hot fluids, respectively, so as to calculate the total heat transfer coefficient.
7. Calculate the required heat transfer area.
8. Turn back to calculate the heat exchange area.
9. Check the pressure drop. The allowable pressure drop often becomes a limiting factor in the design of the plate heat exchanger. The design always requires sufficient pressure drop. If no matter how the process layout is changed, the relationship between heat exchange load, flow rate and allowable pressure drop cannot be coordinated, only inefficient design solutions can be made. If in the design, you have not been able to obtain a satisfactory design solution, you can consider changing the board type.