Denso develops new smaller and more efficient condenser

May 15, 2012: Global automotive supplier Denso has developed a smaller and more efficient condenser, which helps increase fuel efficiency, while allowing carmakers to have greater design flexibility inside the engine compartment. Compared to conventional models, the new Global Inner-fin Condenser (GIC) is 30 percent smaller.

By exchanging heat with air, the condenser cools the high-pressure refrigerant vapour and condenses it into a liquid refrigerant. “To condense the vapour into a liquid refrigerant, the condenser must first remove the heat,” said Akio Shikamura, senior executive director of Denso's Thermal Systems Business Group (pictured). “Increasing the efficiency of the condenser’s heat removal process is one way to improve the overall efficiency of the air-conditioning system, which improves vehicle fuel economy, and helps cool the cabin more quickly.”

Smaller and more efficient

As carmakers worldwide are looking for increased fuel efficiency and more under-the-hood design flexibility, Denso focused on developing a high-performance condenser that was more efficient, but also smaller than previous generations. To achieve the increase in efficiency, the company focused on increasing the heat removal performance of GIC, which is dependent upon the design of the components like tubes and fins.

Tubes and fins

To more efficiently transfer the refrigerant’s heat flowing in the tubes, the size of the tube’s inner fins were reduced and the density of inner fins inside each tube were maximised, which increased the heat transfer area by 20 percent. In addition, despite how thin it is, the capacity of the inner fin tube was increased by 25 percent, compared to conventional models. The new inner-fin tube has 25 percent more room, which enables even more amount of refrigerant to flow in the tube without increasing power consumption. This new design allows for the flexibility of new, more environmentally friendly refrigerants to be introduced in the future.

Denso further improved the GIC’s heat removal process by increasing the number of louvres in each fin by 30 percent per unit area. Despite this increase in louvers, the size of the fin was not increased.

Combined, these innovations resulted in reducing the GIC product width from 16mm to 11mm, which is a 30 percent reduction in size from conventional models.