Heat imbalance between HTRI calculation and formula-based calculation
Thread Content
I would like to ask everyone: the heat transfer rate is 1,595,028 W, and the area is 135.88. The issue raised by the design team is that 1,595,028 > 332.23 × 135.88 × 23.7. What is the problem in this calculation? The design margin is 20%. Thank you.
Please check the HTRI calculation result Runtime Message. This situation is generally caused by a large difference between the heat load input manually and the heat load calculated based on flow rate and temperature difference. In your case, it can be estimated that the heat load entered manually is much smaller than flow rate * temperature difference. In the TEMA calculation sheet, the value of Heat Exchanged W should be the average of the two values.
You’d better check carefully what you’ve entered – was a heat transfer amount specified? Similar to what a colleague upstairs said.
It is normal for the heat exchange load and the calculated values of these parameters not to match exactly, but such a large difference is usually due to conflicting input parameters; it is advisable to check the operation information
It is recommended to attend HTRI’s video lecture on the 29th of this month; contact via WeChat at 13910125324
The causal relationship is incorrect; the heat transfer rate is calculated based on mass flow rate, specific heat, and the temperature difference for heat transfer, not in the way you have calculated it.
The heat load was entered in this field. 1595028W is calculated by the software based on flow rate, specific heat, and the temperature difference between the inlet and outlet. The heat transfer area is determined using the heat load manually entered for those locations, the heat transfer coefficient calculated from the properties of the fluid and the structure of the heat exchanger. Therefore, 332.23X135.88X23.7 represents the heat load that was manually entered. The above situation occurs when there is a significant difference between the two heat loads. Manually entered heat loads can be deleted. The software will calculate the heat exchange area based on the heat load determined by flow rate, specific heat, and the temperature difference between the inlet and outlet. However, the heat load calculated by Htri based on flow rate, specific heat, and the temperature difference between the inlet and outlet may deviate from the actual heat load, especially when phase change is involved. Alternatively, manually consult the manual data to calculate based on flow rate, specific heat, and temperature differences between the inlet and outlet, or use ASPEN simulation to verify the heat load. . Or, if you’re not sure, go with the higher heat load