Effect of Inclination on the Performance of a Compact Brazed Plate Condenser and Evaporator.
Effect of Inclination on the Performance of a Compact
Brazed Plate Condenser and Evaporator.
Kedzierski, M. A.
NISTIR 5767; 31 p. November 1995.
Heat Transfer Engineering, Vol. 18, No. 3, 25-38, 1997.
Sponsor:Trane Co., La Crosse, WI
Available from: National Technical Information Service
Order number: PB96-136973
building technology; brazed plate; compact heat
exchanger; evaporator; condenser; gravity
This study experimentally quantified the change in heat
transfer and pressure drop associated with tilting a
compact brazed plate heat exchanger from the intended
vertical position. Both clockwise and counterclockwise
rotations within a plane perpendicular to the fittings
were examined. A SWEP B15x36 was tested as an R-22
evaporator and condenser under fixed refrigerant state
conditions suitable to high-efficiency water-source heat
pumps. This study showed that a substantial performance
penalty occurred when the evaporator was rotated past 30
deg from the vertical. The evaporator heat transfer in
the horizontal position was 60-75% of the vertical
value. For a rotation angle of 30 deg, the degraded heat
transfer was within 5% of the vertical value. Rotation
direction and entering refrigerant state had little
effect on the performance of the evaporator for rotation
angles less than 60 deg. Only when the evaporator was
rotated to the horizontal position did rotation
direction and refrigerant state have much effect. At
the horizontal position, a subcooled-entering
refrigerant and a counterclockwise rotation both tended
to lessen the heat transfer degradation. Rotation of
the condenser to the horizontal position improved the
overall heat transfer coefficient by approximately
17-30%. Rotation direction had a negligible effect on
the performance of the condenser for angles less than 60
deg. Both the evaporator and condenser pressure drops
were influenced by flow distribution changes as the heat
exchangers were rotated.