Investigation of heat exchanger inclination in forced-draught air-cooled heat exchangers

The purpose of this study is to determine the influence of inclining the heat exchanger relative to the fan in a forced draught air-cooled heat exchanger. Since inclination increases plenum depth, the effect of inclination is also compared with increasing plenum depth without inclination. The experimental study shows that inclination improves thermal performance by only 0.5%, when compared with a baseline non-inclined case with a shallow plenum. Similarly, increasing plenum depth without inclination has a thermal performance benefit of approximately 1%. The numerical study shows that, as the heat exchanger is inclined, the low velocity core at the centre of the heat exchanger moves to one side.

► Inclination only makes a small difference to thermal performance of ACHE.
► Increasing plenum depth only is slightly more effective – 1% benefit over baseline.
► The flow tends to move to one side as the heat exchanger is inclined.
► This side is a good location for a performance limiting heat exchanger.