This invention is an air-cooled oblique-tube heat exchanger with plain fins. This invention offers greatly reduced air-side pressure drop by 14.4% for 1-3 m/s and higher heat transfer by 13.3% at the same fan power, as compared to commercial 1-row circular-tube condenser coils with corrugated fins. The advantages were derived from the slender shape of oblique tubes causing minimal resistance to the passage of air and much reduced wake zone resulting higher temperature gradients and greater heat transfer behind the oblique tubes. An integration of a middle rib in the tube strengthens its rigidity up to 50 bar, thus allowing potential wide adoption for water to refrigerant-based applications. Controlled atmospheric brazing can be used to braze oblique tubes, fins, headers, baffles and fluid ports in one process and to improve the joining quality between the fins and the oblique tubes.
It can completely handle the latent heat load, so low lift chiller may be used implying greater COP. Ultra-low temperature (Only 8 °C more than cooling-tower water temperature) waste-heat from condenser required for regeneration. Smaller capacity compressor and smaller evaporator/condenser coil size required for the same cooling load.
The applications of this invention will be in residential and building air conditioning (AC) systems for AC outdoor units and air handing units as well as in cooling systems for data centers.
20% of the total energy consumed in developed countries is utilized for air-conditioning. Thus, especially for places experiencing warm and humid conditions, besides the huge energy bills paid by the end-users, air-conditioning equipment is responsible for enormous carbon emission. Thus, HVAC industry requires innovative solution which can substantially boost the performance of air-conditioners. Hyper-efficient dehumidifiers that can utilize the low-temperature heat that the condenser otherwise rejects, need to be designed to completely eliminate the latent-heat load on the evaporator and help make air-conditioners highly energy efficient.