Calculate the average temperature difference of the plate heat exchanger
Recently, some customers have asked our customer service how to calculate the average temperature difference of plate heat exchangers. Let me explain it to you today!
1. Calculate the unknown temperature or flow, calculate the unknown temperature or flow through the heat balance equation, and also calculate the heat load Q.
2. Choose a suitable heat exchanger plate model, and choose a suitable heat exchanger plate model according to the amount of heat exchange and flow.
The choice of heat exchanger plate model depends on the specific working conditions. When the flow rate is large and the pressure drop is low, a plate type with a lower resistance should be used; otherwise, a plate type 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 flow and the number of channels, initially select the cold and hot fluid flow and the number of channels, and calculate the flow rate from this.
5. Find the average temperature difference.
6. To find the convective heat transfer coefficient and total heat transfer coefficient, first obtain the convective heat transfer coefficients of cold and hot fluids respectively, and then calculate the total heat transfer coefficient.
7. Calculate the required heat exchange area.
8. Compound heat exchange area.
9. Check the pressure drop. The allowable pressure drop is often a limiting factor in the design of the plate heat exchanger. The design always requires sufficient allowable pressure drop. If the relationship between heat transfer load, flow rate and allowable pressure drop cannot be coordinated no matter how the process layout is changed, only inefficient design schemes can be made. If in the design, the satisfactory design scheme has not been obtained, you can consider changing the plate type.
