Design of Secondary Lens for LED Fishing Lamps to Evaluation Catches Energy Efficiency in Saury Fishing

This paper employed ray tracing to design a spotlighting optical lens. TracePro was used to design and simulate a light-emitting diode (LED) lamp for saury fishing with an optimized light distribution that focused light into a fishing net beside a fishing vessel. In the simulation analysis, the irradiance of incandescent lamps deployed on saury fishing vessels was taken as the base figure. The average irradiance of LEDs without the designed lens was 0.83 times the incandescent lamps, whereas the average irradiance of the LEDs with the designed lens was 1.6 times the incandescent lamps. However, considering the usage habits of saury fishing boats, the experimental testing installed the combination on two saury fishing boats. The average irradiance of a combination of LEDs with the designed lens and incandescent lamps ship was 1.14 times the incandescent lamps ship. The boats sailed into the northwest pacific to conduct fuel consumption and catch experiments over three voyages. Savings of 13.0% were achieved in fuel cost required per ton of catch volume, and savings of 20.2% were achieved in average fuel consumption. No significant difference in terms of catch volume was revealed between combination lamp poles and incandescent lamp poles. The proposed lens design effectively enhanced the functionality of LED fishing lights on saury fishing boats. Substituting a portion of incandescent lamps with LED lamps using the proposed lens could effectively save fuel without significantly affecting catch volumes.