Graphite side heater of layered serpentine polycrystalline silicon ingot furnace

Abstract

The invention discloses a graphite side heater of a layered serpentine polycrystalline silicon ingot furnace, and relates to the technical field of photovoltaic equipment ingot. The graphite side heater comprises 8 side heater monomers, 3 lifting arms, 3 electrodes and 4 corner connecting plates. The side heater monomers are serpentine, an upper layer side heater comprises four side heater monomers, a lower layer side heater comprises four side heater monomers, the lower middle sections of the lifting arms are connected with the upper layer side heater and the lower layer side heater, so thatthe upper layer side heater and the lower layer side heater are connected in parallel, the lifting arms divide the side heater into equal three phases, the electrodes are connected with the top ends of the lifting arms, and the corner connecting plates connect the upper layer side heater monomers and the lower layer side heater monomers, and connect left-right adjacent side heater monomers in eachsame layer. The graphite side heater is designed as an in-parallel upper-lower two-layer structure, the resistance of the side heater can be effectively reduced, the peak power of the side heater canbe improved, and double requirements of G8 and a larger size ingot furnace on the power and the thickness of the graphite side heater can be balanced.

Description

technical field [0001] The invention relates to the technical field of photovoltaic equipment ingot casting, in particular to a graphite side heater of a layered serpentine polysilicon ingot furnace. Background technique [0002] Solar photovoltaic power generation is one of the emerging forms of renewable energy utilization. In recent years, the solar photovoltaic industry has achieved rapid development both at home and abroad. In the photovoltaic industry, crystalline silicon solar cells are the most widely used, including monocrystalline silicon wafers and polycrystalline silicon wafers. Polycrystalline silicon wafers occupy a dominant position in the solar photovoltaic industry due to their advantages of high production capacity and low cost. [0003] The polysilicon ingot furnace is the main equipment for producing solar-grade polysilicon ingots. The traditional ingot furnace heater adopts resistance heating, and the heating source is a 50Hz three-phase AC power supply....

AI Technical Summary

Problems solved by technology

In the prior art, most of the polysilicon ingot furnace heaters use large-period serpentine graphite heaters, which are connected in a triangle and surround the crucible guard plate. The electromagnetic field of the heater is generated in the penetration layer on the surface of the molten silicon and moves upward periodically with the shape of the heater. and the downward Lorentz force, which seriously affects the melt convection and the stability of the solid-liquid interface of the long crystal

[0004] In addition, with the continuous upgrading of polysilicon ingot furnaces, ingot furnaces such as G7 and G8 have gradually appeared and put into production, and the amount of feed and the size of silicon ingots have increased greatly, which has increased the length of side heaters surrounding the crucible guard plate. The peak power required for the heater also increases

At the same time, the compact thermal field space of the ingot furnace requires that the thickness of the heater should not be too large. The thicker graphite heater occupies more thermal field space, which not only limits the size of the silicon ingot, but also makes it easy to load and unload due to manual errors. Causes collisions between shield heaters, shortening heater life

Therefore, under the condition that the length and peak power of the side heater increase at the same time, it is difficult for the single-layer graphite side heater to meet the double-layer requirements for heater thickness and power of large-sized ingot furnaces such as G7 and G8.

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