Research On The Methods Of Lowering The Junction Temperature Of LED Underwater Fish Aggregation Lamp

A LED fish aggregation lamp which is used to attract and gather fish is an important equipment in the light fishing industry.Compared with the metal halide fish aggregation lamp which is now widely used in the light fishing industry,LED fish aggregation lamp has the advantages of energy saving,environmental protection,quick response,good spectrum property,long lifetime,strong directionality and so on.However,the LED underwater fish aggregation lamp suffers from luminous decay,expensive price and so on,and the main reason of luminous decay is that the junction temperature is too high.The purpose of this paper is to lower the junction temperature of the LED underwater fish aggregation lamp by optimizing the structure of the heat sink,using materials with higher thermal conductivity,and increasing the light use efficiency,so as to reduce luminous decay,extend service life and reduce costs.The main results are as follows:1.The computational fluid dynamics(CFD)method is used and an orthogonal experiment(with four factors and four levels)is designed to study the effects of the length,thickness and spacing of the fins and the semicylinder spacing of the heat sink(four factors)on the chip maximum temperature and the mass of the heat sink.Then,the optimal level combination is obtained.The structure of the heat sink has been optimized by the orthogonal experiment,and the cooling performance of the lamp is improved,as a result,the junction temperature can be lowered.2.The effect of different thermal conductivity materials on junction temperature is studied.Studies have shown that compared to replacing heat sink aluminum materials with copper materials and replacing aluminum substrates with ceramic substrates,using thermal greases with higher thermal conductivity to lower the junction temperature is more economical and can meet the cooling requirements of the lamp.When the thermal conductivity of the thermal grease increases to 3.4W/(m ?K),the chip maximum temperature is 66.47°C.Thus,the chip temperature drops 1.75°C and the cost only increases 14.2 yuan,which is more reasonable and saves costs.3.The methods to improve the light use efficiency and their effects on the junction temperature are studied.Studies in this thesis have shown that the effect of attracting fish by the narrow bands LED underwater fish aggregation lamp whose light color is sensitive to fishes is better than the white one.Selecting an appropriate method and phosphor concentration to produce the LED underwater fish aggregation lamp according to the sensitive bands of the fish can increase the effective spectrum proportion of attracting fish,improve the light use efficiency and reduce the power of the lamp efficiently.As a result,the junction temperature can be lowered.The research on the methods of lowering the junction temperature of LED underwater fish aggregation lamp is conducive to the sustainable development of light fishing industry,promoting the rational use of marine fishery resources,and improving the economic income of fishermen.It is of great significance to the future development of marine fishery in our country.