## Surface temperature Calculations (HX)

## Surface temperature Calculations (HX)

(OP)

Hi,

Could anyone please help me regarding calculating the surface temperature of HX tube and tubes are covered by aluminium sheet? In this case, the 5.02m^2 area is exposed to sun, 500kW/m^2 peak flux on surface, total no of tubes 20 are arranged in parallel manner in one row (parallel flow) and covered with aluminum sheet and the spacing between tubes is 2mm.

I have already calculated total thermal resistance, heat transfer to fluid , heat absorbed by tube, heat losses include reflection and convection. But the outlet temperature is not according to desired output.So what approach should i follow to solve this problem? The attachment includes the equations which i'm using to calculate the surface temperature. Thanks

Could anyone please help me regarding calculating the surface temperature of HX tube and tubes are covered by aluminium sheet? In this case, the 5.02m^2 area is exposed to sun, 500kW/m^2 peak flux on surface, total no of tubes 20 are arranged in parallel manner in one row (parallel flow) and covered with aluminum sheet and the spacing between tubes is 2mm.

I have already calculated total thermal resistance, heat transfer to fluid , heat absorbed by tube, heat losses include reflection and convection. But the outlet temperature is not according to desired output.So what approach should i follow to solve this problem? The attachment includes the equations which i'm using to calculate the surface temperature. Thanks

## RE: Surface temperature Calculations (HX)

TTFN (ta ta for now)

I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg

FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

## RE: Surface temperature Calculations (HX)

## RE: Surface temperature Calculations (HX)

TTFN (ta ta for now)

I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg

FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

## RE: Surface temperature Calculations (HX)

## RE: Surface temperature Calculations (HX)

TTFN (ta ta for now)

I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg

FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

## RE: Surface temperature Calculations (HX)

## RE: Surface temperature Calculations (HX)

I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg

## RE: Surface temperature Calculations (HX)

## RE: Surface temperature Calculations (HX)

is the heat exchanger being heated by the sun, or losing its heat by natural convectin to the (hot ?) or "cool" air flowing by the heat exchanger tubes that are themselves shaded under the aluminum sheet?

Is the Al sheet re-radiating its heat energy to the top tubes of the heat exchanger?

No info, no valid answers. Only bad guesses.

## RE: Surface temperature Calculations (HX)

I have attached some rough diagrams of the arrangement of the tube & other stuff. I think you can get some good idea from this scenario. Thanks

## RE: Surface temperature Calculations (HX)

You continue to make it difficult to help you.

I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg

## RE: Surface temperature Calculations (HX)

In fin case, the total area is considered carefully as area of conduction isn't simple.

Energy balance eq in case of heat transfer through tube;

The total thermal resistance is combination of conduction and convection.

By solving above those eq simultaneously, Ts for tube and fin can be determined. After it, average surface temperature is considered as overall surface temperature.Thanks

## RE: Surface temperature Calculations (HX)