CN203065635U - Bottom enhanced cooling device - Google Patents

Abstract

The utility model relates to a bottom enhanced cooling device, comprising a quartz crucible, a graphite crucible, a heater, a heat exchange platform and a graphite upright post, wherein the quartz crucible is placed in the graphite crucible; the graphite crucible is placed on the heat exchange platform; the heater is arranged at the periphery of the graphite crucible; and the graphite upright post is connected with the heat exchange platform and can convey cooling gas to the heat exchange platform. The bottom enhanced cooling device controls the shape of a solid liquid interface through different radiating and cooling effects and increases the supercooling degree at the early stage of crystal growth so as to solve the problem that a big silicon ingot is difficult to radiate and improve the crystal growth quality.

Description

A bottom enhanced cooling device

technical field

The utility model relates to a cooling device, in particular to a bottom enhanced cooling device, which is used to improve the quality of ingots and further improve the conversion efficiency of batteries, and belongs to the technical field of crystalline silicon casting equipment.

Background technique

Polysilicon ingots are widely recognized by the photovoltaic industry for their low cost and high output. However, excessive defects and impurities in the casting process will affect the conversion efficiency of polycrystalline silicon cells. Therefore, controlling the thermal field in the ingot casting process, reducing crystal defects and impurities, and improving battery conversion efficiency have become common concerns.

At present, the commonly used thermal field control method is mainly realized by adjusting the heater power and opening the heat insulation layer. However, as the ingot tends to be more and more large-scale, and the application of quasi-single crystal casting technology, the requirements for thermal field control are also getting higher and higher. Simply relying on these two adjustments cannot meet the heat dissipation requirements inside the large silicon ingot, let alone control the crystal growth orientation to reduce the deposition of crystal defects and impurities.

Therefore, in order to solve the above technical problems, it is indeed necessary to provide a bottom enhanced cooling device to overcome the above-mentioned defects in the prior art.

Utility model content

The purpose of the utility model is to provide a bottom enhanced cooling device with simple structure and good heat dissipation performance, which solves the problem of difficult heat dissipation inside a large silicon ingot.

In order to achieve the above object, the technical solution adopted by the utility model is: a bottom enhanced cooling device, which includes a quartz crucible, a graphite crucible, a heater, a heat exchange table and a graphite column; wherein, the quartz crucible is accommodated in the graphite crucible The graphite crucible is placed on the heat exchange table; the heater is arranged around the graphite crucible; the graphite column is connected with the heat exchange table, and can send cooling gas into the heat exchange table.

The enhanced cooling device at the bottom of the present utility model is further set as follows: a central hole is provided in the center of the heat exchange platform, and an opening is respectively provided on the four corners of the heat exchange platform, and the central hole and the four openings The holes communicate with a graphite column respectively.

The enhanced cooling device at the bottom of the present invention is further configured as follows: a plurality of zigzag grooves are arranged at intervals on the heat exchange platform, and the plurality of zigzag grooves communicate with each other.

The enhanced cooling device at the bottom of the utility model is further configured as follows: it further includes a heat insulation cage; the heat exchange table, quartz crucible, graphite crucible and heater are all accommodated in the heat insulation cage.

The enhanced cooling device at the bottom of the present invention is further configured as follows: the heat insulation cage is accommodated in a vacuum furnace body, and an air supply pipe is passed into the vacuum furnace body.

Compared with the prior art, the utility model has the following beneficial effects: the bottom enhanced cooling device of the utility model controls the shape of the solid-liquid interface through different heat dissipation and cooling effects, and improves the supercooling degree in the initial stage of crystal growth, thereby solving the problem of large silicon Difficult heat dissipation inside the ingot to improve the quality of the crystal growth.

Description of drawings

Fig. 1 is a structural schematic diagram of a bottom enhanced cooling device of the present invention.

Fig. 2 is a schematic diagram of the heat exchange platform of the bottom enhanced cooling device of the present invention.

Detailed ways

Please refer to the accompanying drawings 1 and 2 of the specification. The utility model is a bottom enhanced cooling device, which is composed of a quartz crucible 1, a graphite crucible 2, a heater 3, a heat exchange table 4 and a graphite column 5. .

Wherein, the silicon material 6 is housed in the quartz crucible 1 , which is housed in the graphite crucible 2 and protected by the graphite crucible 2 . The graphite crucible 2 is placed on a heat exchange platform 4 .

The heater 3 is arranged around the graphite crucible 2 and can heat the silicon material 6 .

The graphite column 5 is connected to the heat exchange platform 4 and can send cooling gas into the heat exchange platform 4 .

Further, a central hole 41 is provided in the center of the heat exchange platform 4, and an opening 42 is respectively provided on the four corners of the heat exchange platform 4, and the central hole 41 and the four openings 42 are respectively connected with A graphite column 5 communicates so that cooling gas can enter and exit the heat exchange table 4 . On the heat exchanging table 4, there are several square-shaped grooves 43 arranged at intervals, and the several square-shaped grooves 43 communicate with each other, so as to ensure that the cooling gas enters through the central hole 41, flows to the surrounding openings 42, and finally opens the surrounding openings 42 The gas flows out of the heat exchange platform 4 , or enters the heat exchange platform 4 through the opening 42 , flows toward the center hole 41 , and finally flows out through the center hole 41 .

The enhanced cooling device at the bottom of the utility model further includes a thermal insulation cage 7; the heat exchange table 4, quartz crucible 1, graphite crucible 2 and heater 3 are all housed in the thermal insulation cage 7. The heat insulation cage 7 is accommodated in a vacuum furnace body 8 , and a gas supply pipe 9 is connected into the vacuum furnace body 8 .

The cooling method of the bottom enhanced cooling device of the present utility model is as follows:

1) Seed crystal melting stage: heating by heater 3 will make the temperature of the side of the silicon ingot higher than the center during the heating process, and the surrounding of the seed crystal will melt faster than the middle. In order to maintain a consistent melting rate, the cooling gas will flow from the heat exchange table The surrounding openings 42 of 4 pass through, and the cooling gas carrying part of the heat moves further to the central hole 41 of the heat exchange table 4, and finally flows out from the central hole 41, forming a temperature gradient of cold around and hot in the center to neutralize the heater 3 Convex interface with cold sides and hot center formed by heating;

2) After melting, since the heat inside the silicon ingot cannot be dissipated in time, the power of the heater on the outer wall is reduced, forming a concave surface with a cold side and a hot center. 42 flows out to form a reverse cooling effect; in addition, due to the higher supercooling requirement in the initial crystal growth stage, the flow rate of the cooling gas (argon) also needs to be appropriately increased, that is, the cooling gas flow in step 2) The inflow rate is greater than the cooling gas inflow rate in step 1), to improve the nucleation efficiency;

3) After the initial nucleation is completed, reduce the cooling gas flow rate and maintain a weak cooling effect until the end of cooling.

The specific implementation above is only a preferred embodiment of this creation, and is not intended to limit this creation. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this creation should be included in this creation. within the scope of protection.

Claims (5)

1. A bottom enhanced cooling device is characterized in that: it comprises a quartz crucible, a graphite crucible, a heater, a heat exchange table and a graphite column; wherein, the quartz crucible is placed in the graphite crucible; the graphite crucible is placed in the heat exchange on the platform; the heater is arranged around the graphite crucible; the graphite column is connected to the heat exchange platform, and can send cooling gas into the heat exchange platform. 2. The bottom enhanced cooling device according to claim 1, characterized in that: a center hole is provided at the center of the heat exchange platform, and an opening is respectively provided at the four corners of the heat exchange platform, and the The central hole and the four openings communicate with a graphite column respectively. 3. The enhanced bottom cooling device according to claim 2, characterized in that: a plurality of zigzag grooves are arranged at intervals on the heat exchange platform, and the plurality of zigzag grooves communicate with each other. 4. The bottom enhanced cooling device according to claim 3, characterized in that: it further comprises a thermal insulation cage; the heat exchange table, quartz crucible, graphite crucible, and heater are all housed in the thermal insulation cage. 5 . The enhanced bottom cooling device according to claim 4 , wherein the heat insulation cage is housed in a vacuum furnace body, and a gas delivery pipe is opened into the vacuum furnace body. 6 .

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