What type of heat exchanger is suitable for heat exchange between flue gas and air?
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This post was last edited by “Low-key Pro” on December 28, 2018, at 12:55. Flue gas temperature: 320–120; air temperature: 60–260. Flow rate: 300 Nm³/h. Everyone is welcome to discuss
Can a fully welded plate type be used when the dust content in the flue gas is very low?
Is there anyone who can help calculate how large an area is required for an air preheater and a shell-and-tube heat exchanger? \ud83d\ude0a
@Wiseboy expert, could you help take a look?:)
I think they are all air preheaters; it’s simpler that way
Thank you for the reply. I’m considering using an air preheater, but I’m not sure how much area it will require
Thank you for the reply. Heat pipes seem expensive, so we might not consider using them
This won’t be taken into account; it’s just a simple thermodynamic calculation
You can calculate this by yourself. First, convert the smoke and air into masses (you can determine the density using the average temperature). With a temperature difference and specific heat available, the LMTD can be calculated as well. Then decide which type of heat exchanger to use; take the average value for the thermal conductivity, and from that you can find the area required. Multiply that by 1.2… and you’ll get the desired final area. It’s really not that difficult; give it a try by practicing on your own
This post was last edited by “Low-key Expert” on December 28, 2018, at 10:36. The air flow rate is converted to 380 kg/h; the heat load is 21.3 kW. I’m considering using an air preheater. Assuming counterflow conditions, the logarithmic temperature difference is 60, and the heat transfer coefficient is taken as 20. The resulting surface area is 17.75. Could you please check whether these calculations are correct?