Solar photovoltaic cell spliced heat preservation sintering furnace

Abstract

The application provides a solar photovoltaic cell splicing type heat preservation sintering furnace, which comprises drying zones, sintering zones and cooling zones connected in sequence, each temperature zone comprises at least one furnace body module, the furnace body module comprises an upper cavity and a lower cavity, the upper cavity and the lower cavity are spliced together and enclose a sintering cavity, the furnace body modules are spliced and extended along the length direction to form the sintering furnace, and heat dissipation devices for preventing the furnace body modules from being damaged due to thermal expansion are arranged at the connecting positions of the two furnace body modules; the influence of thermal expansion on the sintering furnace is reduced, and the sealing performance of the connection between the furnace body modules is improved.

Description

Technical Field

[0001] This invention relates to the field of solar photovoltaic cell production, specifically to a solar photovoltaic cell splicing heat preservation sintering furnace. Background Technology

[0002] A solar cell sintering furnace is a specialized piece of equipment used to manufacture solar cells. It employs high-temperature sintering technology to fuse cell materials into a single, unified structure. Specifically, the furnace uses the high temperatures generated by heating lamps to dry and sinter electrode materials, such as silver paste, printed on the silicon wafer of a solar photovoltaic cell, into a solid state. The electrode materials are then tightly bonded to the silicon wafer, forming an ohmic contact. This is a crucial step in the solar cell manufacturing process; the sintering process makes the internal structure of the cell more compact, thereby improving the cell's efficiency and stability.

[0003] Currently, sintering furnaces are integrated structures, including drying, sintering, and cooling zones. The temperature difference between these zones is significant. According to the principle of thermal expansion and contraction, the furnace body parts with higher temperatures will undergo greater deformation, while the furnace body parts with lower temperatures will undergo smaller deformation. This can cause gaps in the furnace shell and even damage to the sintering furnace. It can also lead to heat leakage inside the sintering chamber and even allow cold air from outside to enter the sintering chamber, resulting in energy loss and affecting the sintering quality and efficiency of the solar cells. At the same time, integrated sintering furnaces are difficult to maintain and have high replacement costs.

[0004] For example, a sintering furnace with adjustable temperature zones for producing battery cells, disclosed in Chinese patent literature (publication number CN110940186A), consists of a lower furnace body and an upper furnace body covering the lower furnace body. The upper and lower furnace bodies have identical structures and are symmetrically arranged. The lower furnace body has several temperature zones, which are separated by heat insulation plates. The heat insulation plates are detachably installed in the lower furnace body. Several heating lamps are installed in each temperature zone, and the temperature zones in the upper furnace body correspond to those in the lower furnace body. This design divides the interior of the sintering furnace into multiple temperature zones using heat insulation plates, with both the upper and lower furnace bodies including different temperature zones. This design cannot avoid the problem of furnace damage caused by thermal expansion and contraction. Meanwhile, the sintering furnace designed in this way consists of a lower furnace body and an upper furnace body covering the lower furnace body. The closed area of ​​the upper and lower cavities is sealed with heat insulation cotton. The sintering furnace under this design also has the problem of poor cavity sealing, which will lead to heat leakage inside the cavity and cold air from the outside can easily enter the cavity, resulting in energy loss and affecting the sintering quality and efficiency of the solar cells. Summary of the Invention

[0005] To address the problems in the prior art, this invention provides a solar photovoltaic cell modular heat-insulating sintering furnace, comprising a drying zone, a sintering zone, and a cooling zone connected in sequence. Each zone includes at least one furnace body module, which includes an upper cavity and a lower cavity. The upper cavity and the lower cavity are joined together to form a sintering cavity. The furnace body modules are sequentially joined and extended along their length to form a sintering furnace. A heat dissipation device is provided at the connection between two adjacent furnace body modules to prevent damage to the furnace body modules due to thermal expansion.

[0006] Furthermore, the furnace module is configured from the outside to the inside as an outer shell layer, a heat insulation layer, and a heat insulation layer. An axially extending transmission guide rail is provided on the inner side wall of the furnace module. A transmission mesh belt carrying silicon wafers is provided on the transmission guide rail. Heating lamps are symmetrically installed above and below the transmission mesh belt.

[0007] Furthermore, the heat dissipation device includes heat dissipation fins disposed at both ends of the outer shell layer, and a telescopic sleeve fitted at the connection point of the outer shell layers of two adjacent furnace body modules.

[0008] Furthermore, each end of the furnace body module is provided with a groove and a protrusion that matches the groove. The protrusion at one end of the furnace body module is embedded into the groove at one end of the other furnace body module to complete the splicing between the two furnace body modules.

[0009] Furthermore, flexible high-temperature resistant gaskets are provided on the flat surfaces on both sides of the protrusion to seal the contact surfaces of the two furnace modules and buffer the thermal expansion impact between the two furnace modules.

[0010] Furthermore, the bottom of the side wall of the upper cavity is provided with an upper cavity groove, and the top of the side wall of the lower cavity is provided with a lower cavity boss that is adapted to the upper cavity groove. The lower cavity boss is embedded into the upper cavity groove to complete the splicing of the upper cavity and the lower cavity.

[0011] Furthermore, flexible high-temperature resistant gaskets are provided on the planes on both sides of the lower cavity boss to achieve sealing of the contact surfaces between the upper and lower cavities, while buffering the thermal expansion impact between the upper and lower cavities.

[0012] Furthermore, a ramp is provided between the bottom plate of the lower cavity and the side wall.

[0013] Furthermore, the surface of the insulation layer inside the furnace module is coated with a high-temperature resistant reflective layer to reduce heat loss.

[0014] Furthermore, heat insulation plates are installed between furnace modules in different temperature zones.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1. The solar photovoltaic cell splicing heat-insulating sintering furnace of the present invention includes a drying zone, a sintering zone, and a cooling zone connected in sequence. Each temperature zone consists of at least one furnace body module. The furnace body modules are spliced ​​and extended sequentially along the length of the furnace body modules to form the sintering furnace. A heat dissipation device is provided at the connection point of two furnace body modules. The heat dissipation device cools the two furnace body modules, reducing the deformation of the furnace body modules caused by the principle of thermal expansion and contraction. At the same time, according to the second law of thermodynamics, heat naturally flows from the high-temperature region to the low-temperature region. The two ends of the heat dissipation fins are fixed to different furnace body modules respectively. The heat dissipation fins also play a role in heat conduction, guiding heat from the furnace body module with a higher temperature to the furnace body module with a lower temperature. The heat conduction process continues until the two objects reach thermal equilibrium, that is, their temperatures are equal. This reduces the deformation difference of the protrusions and grooves at the connection point of the two furnace body modules, avoiding gaps in the fit of the protrusions and grooves, and preventing damage to the closed-loop furnace body module.

[0017] 2. The solar photovoltaic cell splicing insulated sintering furnace of the present invention has a groove at the bottom of the upper cavity side wall of the furnace body module, and a lower cavity boss at the top of the lower cavity side wall that matches the groove of the upper cavity. The lower cavity boss is embedded into the upper cavity groove to complete the splicing of the upper and lower cavities. Both ends of the furnace body module have grooves and protrusions that match the grooves, respectively. The protrusion at one end of one furnace body module is embedded into the groove at one end of another furnace body module to complete the splicing between the two furnace body modules. This splicing sintering furnace design reduces the impact of thermal expansion between different temperature zones on the sintering furnace, improving the reliability and sustainability of the sintering furnace. At the same time, the concave-convex structure makes the sealing surface tighter, effectively ensuring the sealing performance of the sintering furnace, reducing heat leakage inside the sintering furnace cavity, reducing energy consumption, and improving the sintering quality and efficiency of the solar cells. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the assembly of the sintering furnace of the present invention;

[0019] Figure 2 This is a schematic diagram of the furnace body module of the present invention;

[0020] Figure 3 This is a top view of the furnace body module of the present invention;

[0021] Figure 4 This is a cross-sectional view of the furnace body module of the present invention;

[0022] Figure 5 This is a cross-sectional view of the furnace body module of the present invention.

[0023] Figure 6 This is a schematic diagram of the telescopic sleeve of the present invention;

[0024] Figure 7 This is a schematic diagram of the upper cavity of the present invention;

[0025] Figure 8 This is a schematic diagram of the lower cavity of the present invention;

[0026] Figure 9 This is a schematic diagram of the structure of the heat insulation plate of the present invention;

[0027] In the picture:

[0028] 100. Furnace body module; 110. Upper cavity; 111. Upper cavity groove; 120. Lower cavity; 121. Lower cavity boss; 122. Slope; 130. Groove; 140. Protrusion; 150. Flexible high-temperature resistant gasket; 160. Heat insulation board; 101. Outer shell layer; 102. Insulation layer; 103. Thermal insulation layer; 200. Heat dissipation device; 210. Heat sink; 220. Telescopic sleeve; 221. First telescopic component; 222. Second telescopic component; 300. Conveyor rail; 400. Conveyor belt; 500. Heating lamp tube. Detailed Implementation

[0029] To facilitate understanding of the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] refer to Figures 1-2As shown in the figure, this embodiment provides a solar photovoltaic cell splicing heat-insulating sintering furnace, which includes a drying zone, a sintering zone, and a cooling zone connected in sequence. Each zone includes at least one furnace body module 100. The furnace body module 100 includes an upper cavity 110 and a lower cavity 120. The upper cavity 110 can be spliced ​​with the lower cavity 120 to form a sintering cavity. The furnace body module 100 is a hollow square cylinder structure with openings at both ends. From the outside to the inside, the furnace body module 100 consists of an outer shell layer 101, a heat insulation layer 102, and a thermal insulation layer 103. An axially extending transmission guide rail 300 is provided on the inner side wall of the furnace body module 100. A transmission mesh belt 400 carrying silicon wafers is provided on the transmission guide rail 300. Heating lamps 150 are symmetrically installed above and below the transmission mesh belt 400. The furnace body modules 100 are sequentially spliced ​​and extended along their length to form a sintering furnace. A heat dissipation device 200 is provided at the connection between two adjacent furnace body modules 100 to prevent damage to the furnace body modules 100 due to thermal expansion. After printing, the solar photovoltaic cells are transported to the sintering chamber of the furnace body module 100 via a conveyor belt 400. The cells are transported linearly on the conveyor belt 400. The heating lamps 500 heat up after being connected to the current to heat the sintering chamber. The cells pass through the drying zone, sintering zone and cooling zone in sequence within the sintering chamber. The slurry on the cells undergoes organic drying, pre-sintering, metal melting to form ohmic contact with crystalline silicon, and cooling.

[0031] refer to Figures 2-5 As shown, one end face of the furnace body module 100 has a protrusion 140 along its length, and the other end face of the furnace body module 100 has a groove 130 along its length. The protrusion 140 at one end of the furnace body module 100 is embedded into the groove 130 at the adjacent end of the furnace body module 100, realizing the splicing between the furnace body modules 100, so that the sintering cavity extends axially to form a sintering furnace including a drying zone, a sintering zone, and a cooling zone. The protrusion 140 and the groove 130 of the furnace body module 100 cooperate with each other, making the sealing connection between the furnace body modules 100 tighter, which can reduce the heat loss of the sintering cavity, maintain a constant temperature in the sintering cavity, and a more stable sintering temperature can bring better sintering quality and cell efficiency.

[0032] Preferably, the protrusion 140 at one end of the furnace body module 100 is disposed in the middle of the insulation layer 102 on the side wall of the end of the furnace body module 100. The two sides of the protrusion 140 are respectively a plane composed of the insulation layer 102 and the heat insulation layer 103, and a plane composed of the insulation layer 102 and the outer shell layer 101. A flexible high-temperature resistant gasket 150 is provided on the plane. The flexible high-temperature resistant gasket 150 further improves the sealing performance between the furnace body modules 100, and can also buffer the deformation of the furnace body modules 100 caused by thermal expansion and contraction, thus avoiding damage to the furnace body modules 100 caused by mutual compression.

[0033] refer to Figure 1 , Figure 6 As shown, in some embodiments, a heat dissipation device 200 is provided at the connection point of the two furnace body modules 100 to prevent damage to the furnace body module 100 due to thermal expansion. Preferably, the heat dissipation device 200 includes heat dissipation fins 210 disposed at both ends of the outer shell layer 101 of the furnace body module 100, and a telescopic sleeve 220 sleeved at the connection point of the outer shell layers 101 of the two adjacent furnace body modules 100. The heat dissipation fins 210 have a pleated structure or a finned structure; the heat dissipation fins 210 and the outer shell layer 101 of the furnace body module 100 can be integrally formed, or connected by welding, riveting, bolting, or other methods. In this embodiment, the telescopic sleeve 220 includes a first telescopic member 221 and a second telescopic member 222. The first telescopic member 221 is sleeved on the end of the outer shell layer 101 of the furnace body module 100, and the second telescopic member 222 is sleeved on the end of the outer shell layer 101 of the adjacent furnace body module 100 and can move relative to the first telescopic member 221 to change the axial length of the telescopic sleeve 220 at the connection between two adjacent furnace body modules 100.

[0034] By changing the axial length of the connection between two adjacent furnace body modules 100 through the movement of the second telescopic member 222 relative to the first telescopic member 221, the influence of deformation of the furnace body module 100 caused by thermal expansion can be further reduced, and the sealing performance of the connection between the two furnace body modules 100 can be improved.

[0035] In the above embodiments, the specific structural forms of the first telescopic member 221 and the second telescopic member 222 can be selected according to actual needs. For example, in some embodiments, the first telescopic member 221 has a stepped structure, with its smaller inner diameter end sleeved on the end of the outer shell layer 101 of the furnace body module 100, and its larger inner diameter end sleeved on the second telescopic member 222 and slidably connected to the second telescopic member 222, thereby changing the axial length at the connection between the two furnace body modules 100.

[0036] Because of the large temperature difference between different temperature zones, there is also a large temperature difference between the furnace modules 100 at the connection between the two temperature zones. The furnace module 100 with the higher temperature will undergo greater deformation according to the principle of thermal expansion and contraction, while the furnace module 100 with the lower temperature will undergo smaller deformation according to the principle of thermal expansion and contraction. This will cause gaps to appear in the fit between the protrusions 140 and the grooves 130 at the connection between the two furnace modules 100, and may even cause damage to the protrusions 140 and the grooves 130 at the connection between the two furnace modules 100. This will lead to heat leakage inside the sintering chamber, and even allow cold air from the outside to enter the sintering chamber, resulting in energy loss. It will also affect the sintering quality and efficiency of the solar cells.

[0037] The heat sink 210 installed at the connection point of the two furnace body modules 100 cools the two furnace body modules 100, reducing the deformation of the furnace body modules 100 caused by thermal expansion and contraction. Simultaneously, according to the second law of thermodynamics, heat naturally flows from the high-temperature region to the low-temperature region. The two ends of the telescopic sleeve 220 are respectively fixed to different furnace body modules 100, and the heat dissipation device 200 also plays a role in heat conduction, guiding heat from the high-temperature furnace body module 100 to the low-temperature furnace body module 100. The heat conduction process continues until the two objects reach thermal equilibrium, that is, their temperatures are equal. This reduces the deformation difference between the protrusion 140 and the groove 130 at the connection point of the two furnace body modules 100, avoids gaps in the fit between the protrusion 140 and the groove 130, and prevents damage to the furnace body module 100.

[0038] refer to Figures 7-8 As shown, in some embodiments, the upper cavity 110 is a semi-closed structure with a downward opening, and its bottom side wall has an upward-facing upper cavity groove 111. The lower cavity 120 is a semi-closed structure with an upward-facing opening, and its top side wall has an upward-facing lower cavity boss 121 that matches the upper cavity groove 111. The lower cavity boss 121 is embedded in the cavity groove 111, so that the upper cavity 110 and the lower cavity 120 are joined together to form a sintering cavity. The lower cavity boss 121 and the upper cavity groove 111 fit together tightly, making the sealing connection between the upper cavity 110 and the lower cavity 120 tighter. This reduces heat loss in the sintering cavity, maintains a constant temperature inside the sintering cavity, and a more stable sintering temperature leads to better sintering quality and cell efficiency. Meanwhile, the lower cavity boss 121 is located on the top of the side wall of the lower cavity 120, which is more conducive to cleaning the fallen residue and dust, and avoids the accumulation of residue and dust from affecting the fitting accuracy of the lower cavity boss 121 and the upper cavity groove 111, thereby affecting the sealing effect of the upper cavity 110 and the lower cavity 120.

[0039] Preferably, the lower cavity boss 121 is disposed in the middle of the insulation layer 102 on the side wall of the lower cavity 120. The two sides of the lower cavity boss 121 are respectively a plane composed of the insulation layer 102 and the heat insulation layer 103, and a plane composed of the insulation layer 102 and the outer shell layer 101. A flexible high-temperature resistant gasket 150 is provided on the plane. The flexible high-temperature resistant gasket 150 further improves the sealing performance of the upper cavity 110 and the lower cavity 120, and can also buffer the compression caused by the deformation of the upper cavity 110 and the lower cavity 120 due to thermal expansion and contraction, so as to avoid the upper cavity 110 and the lower cavity 120 squeezing each other and causing damage to the furnace module 100.

[0040] In some embodiments, a downward slope 122 is provided at the connection between the bottom plate and the side wall of the lower cavity 120, which is more conducive to cleaning the dust accumulated on the bottom plate, avoiding the formation of dust dead corners at right angles, and preventing dust accumulation from affecting the quality of the battery cells.

[0041] In some embodiments, the insulation layer 103 inside the furnace module 100 is a heat insulation material with low thermal conductivity, which can effectively prevent heat transfer. To further reduce heat loss, a high-temperature reflective layer is sprayed onto the surface of the heat insulation material. The high-temperature reflective layer can effectively reflect the high-temperature heat radiation generated inside the furnace, reduce the transfer of heat to the external environment, and thus improve the heat preservation performance of the furnace.

[0042] refer to Figure 9 As shown, in some embodiments, heat insulation plates 160 are provided between different temperature zones of the sintering furnace. The heat insulation plates 160 are perpendicular to the length direction of the furnace body module 100 and are respectively provided at the ends of the upper cavity 110 and the lower cavity 120. The left side, right side and top of the heat insulation plate 160 on the upper cavity 110 are tightly connected to the inner wall of the upper cavity 110, and the bottom of the heat insulation plate 160 on the upper cavity 110 extends to a position close to the conveyor belt 400. The bottom center of the heat insulation plate 160 on the upper cavity 110 has a slot for the battery cells to pass through.

[0043] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A solar photovoltaic cell modular heat-insulating sintering furnace, comprising a drying zone, a sintering zone, and a cooling zone connected in sequence, characterized in that, Each temperature zone includes at least one furnace module (100), which includes an upper cavity (110) and a lower cavity (120). The upper cavity (110) and the lower cavity (120) are joined together to form a sintering cavity. The furnace modules (100) are sequentially joined and extended along their length to form a sintering furnace. A heat dissipation device (200) is provided at the connection between two adjacent furnace modules (100) to prevent damage to the furnace modules (100) due to thermal expansion. The furnace module (100) is configured from the outside to the inside as an outer shell layer (101), a heat insulation layer (102), and a thermal insulation layer (103). An axially extending transmission guide rail (300) is provided on the inner wall of the furnace module (100). The guide rail is provided with a conveyor belt (400) for carrying silicon wafers, and heating lamps (500) are symmetrically installed above and below the conveyor belt; the heat dissipation device (200) includes heat sinks (210) at both ends of the outer shell layer (101), and a telescopic sleeve (220) sleeved at the connection of the outer shell layers (101) of two adjacent furnace modules (100); the telescopic sleeve (220) includes a first telescopic member (221) and a second telescopic member (222), the first telescopic member (221) is sleeved at the end of the outer shell layer (101) of the furnace module (100), and the second telescopic member (222) is sleeved at the end of the outer shell layer (101) of the adjacent furnace module (100) and can move relative to the first telescopic member (221).

2. The solar photovoltaic cell splicing heat-insulating sintering furnace according to claim 1, characterized in that, The furnace body module (100) has a groove (130) and a protrusion (140) that matches the groove (130) at both ends. The protrusion (140) at one end of the furnace body module (100) is embedded into the groove (130) at one end of another furnace body module (100) to complete the splicing between two adjacent furnace body modules (100).

3. The solar photovoltaic cell splicing heat-insulating sintering furnace according to claim 2, characterized in that, Flexible high-temperature resistant gaskets (150) are provided on the planes on both sides of the protrusion (140) to seal the contact surfaces of two adjacent furnace modules (100) and buffer the thermal expansion impact between the two furnace modules (100).

4. The solar photovoltaic cell splicing heat-insulating sintering furnace according to claim 1, characterized in that, The upper cavity (110) has an upper cavity groove (111) at the bottom of its side wall, and the lower cavity (120) has a lower cavity boss (121) at the top of its side wall that is adapted to the upper cavity groove (111). The lower cavity boss (121) is embedded in the upper cavity groove (111) to complete the splicing of the upper cavity (110) and the lower cavity (120).

5. The solar photovoltaic cell splicing heat-insulating sintering furnace according to claim 4, characterized in that, Flexible high-temperature resistant gaskets (150) are provided on the planes on both sides of the lower cavity boss (121) to seal the contact surfaces of the upper cavity (110) and the lower cavity (120), while buffering the thermal expansion impact between the upper cavity (110) and the lower cavity (120).

6. The solar photovoltaic cell splicing heat-insulating sintering furnace according to claim 1, characterized in that, The lower cavity (120) has a ramp (122) between the bottom plate and the side wall.

7. The solar photovoltaic cell splicing heat-insulating sintering furnace according to claim 1, characterized in that, The surface of the insulation layer (103) inside the furnace module (100) is coated with a high-temperature resistant reflective layer to reduce heat loss.

8. The solar photovoltaic cell splicing heat-insulating sintering furnace according to claim 1, characterized in that, Insulation plates (160) are provided between furnace modules (100) of different temperature zones.

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