WO2022051012A1

WO2022051012A1 - Sintering apparatus

Info

Publication number: WO2022051012A1
Application number: PCT/US2021/037783
Authority: WO
Inventors: Chuanbo WANG; Dong Zhang
Original assignee: Illinois Tool Works Inc.
Priority date: 2020-09-01
Filing date: 2021-06-17
Publication date: 2022-03-10
Also published as: CN114111329A; TW202228302A

Abstract

This application provides a sintering apparatus, comprising a sintering section, a temperature-drop delay section, and a cooling section. The sintering section is configured to heat and sinter a photovoltaic device at a sintering section sintering temperature, and is configured to enable the photovoltaic device to reach a sintering section preset temperature when the photovoltaic device leaves the sintering section. The temperature-drop delay section is disposed behind the sintering section in a conveying direction of the photovoltaic device, and is configured to apply a temperature-drop delay section heating temperature to the photovoltaic device conveyed from the sintering section into the temperature-drop delay section. The temperature-drop delay section heating temperature is less than the sintering section preset temperature. The cooling section is disposed behind the temperature-drop delay section in the conveying direction of the photovoltaic device. The cooling section is configured to cool the photovoltaic device conveyed from the temperature-drop delay section into the cooling section, and enable the photovoltaic device to reach a cooling section preset temperature when the photovoltaic device leaves the cooling section. The temperature-drop delay section heating temperature is greater than the cooling section preset temperature. The sintering apparatus in this application can provide a photovoltaic device with improved solar energy conversion efficiency, reduced attenuation performance, and longer service life.

Description

SINTERING APPARATUS

Related Applications

[0001] The present application claims the benefit of Chinese Patent Application No. 202010902500.X, filed September 1 , 2020, and to Chinese Patent Application No. 20201 1057981.5, filed September 30, 2020. The entireties of Chinese Patent Application No. 202010902500.X and Chinese Patent Application No. 20201 1057981 .5 are incorporated herein by reference.

Field of the Disclosure

[0002] This application relates to the field of solar cell manufacturing, and more specifically to a sintering apparatus for a photovoltaic device.

Background

[0003] In the production of a photovoltaic device such as a solar cell silicon chip made of crystalline silicon, a sintering apparatus needs to be used to sinter the photovoltaic device. The sintering apparatus usually comprises a drying section, a sintering section, and a cooling section. The photovoltaic device is conveyed by a conveyor belt to sequentially pass through the drying section, the sintering section, and the cooling section. The temperature of the photovoltaic device needs to be controlled within a certain range in each section of the drying section, the sintering section, and the cooling section, to ensure the performance of the photovoltaic device.

Summary

[0004] This application provides a sintering apparatus, used for processing a photovoltaic device. The sintering apparatus comprises a sintering section, a temperature-drop delay section, and a cooling section. The sintering section is provided with a sintering section heating component. The sintering section heating component provides a sintering section sintering temperature. The sintering section is configured to heat and sinter a photovoltaic device conveyed into the sintering section at the sintering section sintering temperature, and is configured to enable the photovoltaic device to reach a sintering section preset temperature when the photovoltaic device leaves the sintering section. The temperature-drop delay section is provided with a temperature-drop delay section heating component. The temperature-drop delay section heating component provides a temperature-drop delay section heating temperature. The temperature-drop delay section is disposed behind the sintering section in a conveying direction of the photovoltaic device, and is configured to apply the temperature-drop delay section heating temperature to the photovoltaic device conveyed from the sintering section into the temperature-drop delay section. The temperature-drop delay section heating temperature is less than the sintering section preset temperature. The cooling section is disposed behind the temperature-drop delay section in the conveying direction of the photovoltaic device. The cooling section provides a cooling temperature. The cooling section is configured to cool the photovoltaic device conveyed from the temperature-drop delay section into the cooling section, and is configured to enable the photovoltaic device to reach a cooling section preset temperature when the photovoltaic device leaves the cooling section. The temperature-drop delay section heating temperature is greater than the cooling temperature.

[0005] For the foregoing sintering apparatus according to this application, the sintering section sintering temperature provided by the sintering section is a multisection temperature.

[0006] For the foregoing sintering apparatus according to this application, the sintering section comprises at least two sintering units. Each of the at least two sintering units provides one sintering section sintering temperature. The temperature-drop delay section comprises one temperature-drop delay unit. The temperature-drop delay unit provides one temperature-drop delay section heating temperature.

[0007] For the foregoing sintering apparatus according to this application, the temperature-drop delay section is configured to enable the photovoltaic device to reach a temperature-drop delay section preset temperature when the photovoltaic device leaves the temperature-drop delay section. The temperature-drop delay section preset temperature is greater than an average temperature of the sintering section preset temperature and the cooling section preset temperature.

[0008] For the foregoing sintering apparatus according to this application, the temperature-drop delay section preset temperature is greater than 80% of the sintering section preset temperature.

[0009] For the foregoing sintering apparatus according to this application, the cooling section comprises at least two cooling units. The photovoltaic device that leaves the cooling section is sequentially conveyed through the at least two cooling units. The temperature-drop delay section is configured to enable a temperature drop rate of the photovoltaic device in the temperature-drop delay section to be less than a temperature drop rate of the photovoltaic device in the cooling unit closest to the temperature-drop delay section.

[0010] For the foregoing sintering apparatus according to this application, the temperature-drop delay section has a temperature-drop delay section length in the conveying direction. The temperature-drop delay section length and the temperature-drop delay section heating temperature are set to enable the temperature drop rate of the photovoltaic device in the temperature-drop delay section to be less than the temperature drop rate of the photovoltaic device in the cooling unit closest to the temperature-drop delay section.

[0011] For the foregoing sintering apparatus according to this application, the temperature-drop delay section heating temperature is greater than or equal to the temperature-drop delay section preset temperature.

[0012] For the foregoing sintering apparatus according to this application, the length of the temperature-drop delay section is 30% to 70% of the length of one of the at least two sintering units.

[0013] For the foregoing sintering apparatus according to this application, the temperature-drop delay section comprises an upper furnace, a lower furnace, and a transport channel. The heating component is disposed between the upper furnace and the lower furnace. A spacing is provided between at least a part of the upper furnace and at least a part of the lower furnace, to form the transport channel used for allowing the photovoltaic device to pass through. Each of two ends of the upper furnace and the lower furnace in the conveying direction is provided with a separating plate, so that the upper furnace and the lower furnace are separated from the sintering section and the cooling section.

[0014] The sintering apparatus in this application can provide a photovoltaic device with improved solar energy conversion efficiency, reduced attenuation performance, and longer service life.

[0015] Other features, advantages, and embodiments of this application will be described or become apparent from the following detailed description, accompanying drawings, and claims. In addition, it should be understood that both the foregoing summary and the following detailed description are exemplary and are intended to provide further explanation rather than to limit the scope that this application seeks to protect. However, the detailed description and specific examples only indicate preferred embodiments of this application. Various changes and modifications within the spirit and scope of this application become apparent to a person skilled in the art from the detailed description.

Brief Description of the Drawings

[0016] These and other features and advantages of the present application can be better understood by reading the following detailed description with reference to the accompanying drawings. Throughout the accompanying drawings, the same reference numerals represent the same components. In the figures:

[0017] FIG. 1 is a front view of a sintering apparatus according to an embodiment of this application;

[0018] FIG. 2A is a three-dimensional view of a temperature-drop delay section of the sintering apparatus shown in FIG. 1 ;

[0019] FIG. 2B is a side view of the temperature-drop delay section of the sintering apparatus shown in FIG. 2A;

[0020] FIG. 3A is an exploded view of the temperature-drop delay section of the sintering apparatus shown in FIG. 2A as seen from bottom to top;

[0021] FIG. 3B is an exploded view of the temperature-drop delay section of the sintering apparatus shown in FIG. 2A as seen from top to bottom;

[0022] FIG. 3C is a sectional view of the temperature-drop delay section of the sintering apparatus shown in FIG. 2A;

[0023] FIG. 4 is a schematic diagram of a distance-temperature relationship of a photovoltaic device in a sintering apparatus in the prior art; and

[0024] FIG. 5 is a schematic diagram of a distance-temperature relationship of a photovoltaic device in the sintering apparatus shown in FIG. 1 .

Detailed Description

[0025] Particular embodiments of the present application are described below with reference to the accompanying drawings which constitute part of this description. It is to be understood that although the terms indicating directions or orientations, such as “up”, “down”, “front”, “rear”, “left”, and “right”, are used in the present application to describe various exemplary structural parts and elements in the present application, these terms used herein are, in order to facilitate the illustration, only determined based on the exemplary orientations as shown in the accompanying drawings. Since the embodiments disclosed in the present application may be arranged according to different orientations, these terms indicating direction are merely illustrative and should not be regarded as limiting. The same reference numerals are used for the same parts in the following accompanying drawings.

[0026] FIG. 1 is a front view of a sintering apparatus 100 according to an embodiment of this application, to show a schematic block structure of the sintering apparatus 100. As shown in FIG. 1 , the sintering apparatus 100 comprises a drying section 101 , a sintering section 102, a temperature-drop delay section 103, and a cooling section 104. A to-be-processed photovoltaic device is transported by a conveyor belt, to sequentially pass through the drying section 101 , the sintering section 102, the temperature-drop delay section 103, and the cooling section 104 to complete sintering.

[0027] A drying section heating component 111 is provided in the drying section 101 . The drying section heating component 111 provides a drying section drying temperature. The drying section heating component 1 11 in the drying section 101 heats the photovoltaic device at the drying section drying temperature, such that the photovoltaic device is heated to a drying section preset temperature when the photovoltaic device leaves the drying section 101 , so as to evaporate an organic solvent on the photovoltaic device. The dried photovoltaic device enters the sintering section 102.

[0028] The sintering section 102 is provided with a sintering section heating component 112. The sintering section heating component 112 provides a sintering section sintering temperature. The sintering section heating component 112 in the sintering section 102 heats the photovoltaic device at the sintering section sintering temperature, to enable the photovoltaic device to be heated to a sintering section preset temperature, that is, a temperature when the photovoltaic device is outputted from the sintering section 102, so as to sinter the photovoltaic device. The sintering section preset temperature of the photovoltaic device is usually greater than 600 degrees.

[0029] The sintered photovoltaic device enters the temperature-drop delay section 103. The temperature-drop delay section 103 is provided with a temperature-drop delay section heating component 113. The temperature-drop delay section heating component 113 provides a temperature-drop delay section heating temperature. The temperature-drop delay section heating component 1 13 of the temperaturedrop delay section 103 applies the temperature-drop delay section heating temperature to the photovoltaic device, such that the photovoltaic device reaches a temperature-drop delay section preset temperature, that is, a temperature when the photovoltaic device is outputted from the temperature-drop delay section 103. The temperature-drop delay section heating temperature is less than the sintering section sintering temperature and is less than the sintering section preset temperature. The temperature-drop delay section preset temperature is less than or equal to the temperature-drop delay section heating temperature. The temperature-drop delay section heating temperature is less than the sintering section sintering temperature and the sintering section preset temperature. Therefore, although the temperature-drop delay section 103 provides a heating temperature, the photovoltaic device that enters the temperature-drop delay section 103 and has the sintering section preset temperature in fact undergoes a temperature drop in the temperature-drop delay section 103, and compared with the case of directly inputting the photovoltaic device from the sintering section 102 into the cooling section 104, such a temperature drop rate is reduced or stopped. In other words, the temperature-drop delay section 103 enables the photovoltaic device that just leaves the sintering section 102 and has a relatively high temperature to undergo a temperature drop at a relatively slow speed, to enable the photovoltaic device to be reduced to an expected temperature at a reduced temperature drop rate.

[0030] The photovoltaic device that leaves the temperature-drop delay section 103 enters the cooling section 104. The cooling section 104 can provide a cooling section cooling temperature to the photovoltaic device, such that the photovoltaic device reaches a cooling section preset temperature, that is, a temperature when the photovoltaic device is outputted from the cooling section 104. The cooling section preset temperature is less than the temperature-drop delay section preset temperature. The cooling section preset temperature is usually 40 degrees to 80 degrees. The cooling section 104 enables the photovoltaic device to undergo a temperature drop at a relatively fast, unreduced or unstopped speed. In an embodiment, the cooling section 104 is provided with a cooling apparatus, but is not provided with a heating apparatus. The cooling apparatus may be an air cooling apparatus (for example, a fan) and/or a water cooling apparatus. When the cooling apparatus is an air cooling apparatus, the cooling temperature in the cooling section 104 is generally an atmospheric environment temperature. When the cooling apparatus is a water cooling apparatus, the cooling temperature in the cooling section 104 is less than the atmospheric environment temperature.

[0031] It needs to be noted that although not shown in FIG. 1 , the drying section

101 , the sintering section 102, the temperature-drop delay section 103, and the cooling section 104 are provided with a communicating transport channel. The conveyor belt is disposed in the transport channel. The photovoltaic device is placed on the conveyor belt. When the conveyor belt operates, the photovoltaic device can sequentially pass through the drying section 101 , the sintering section

102, the temperature-drop delay section 103, and the cooling section 104.

[0032] FIG. 2A is a three-dimensional view of the temperature-drop delay section 103 of the sintering apparatus 100 shown in FIG. 1. FIG. 2B is a side view of the temperature-drop delay section 103 of the sintering apparatus 100 shown in FIG. 2A. As shown in FIG. 2A and FIG. 2B, the temperature-drop delay section 103 comprises a support frame 210, an upper furnace 201 , and a lower furnace 202. The upper furnace 201 and the lower furnace 202 are supported by the support frame 210, to be kept at predetermined positions. A spacing is provided between a part of the upper furnace 201 and a part of the lower furnace 202, to form the transport channel 203. In an example of this application, the temperature-drop delay section 103 is provided with two transport channels 203 arranged in parallel on the left and right. An inlet of the transport channel 203 of the temperature-drop delay section 103 is in communication with an outlet of the transport channel in the sintering section 102, and an outlet of the transport channel 203 of the temperature-drop delay section 103 is in communication with an inlet of the transport channel in the cooling section 104, so that the photovoltaic device that leaves the sintering section 102 can enter the transport channel 203 of the temperature-drop delay section 103, and the photovoltaic device that leaves the temperature-drop delay section 103 can enter the cooling section 104. In addition, the transport channel 203 is further provided with a conveyor belt (not shown), used for carrying and transporting the photovoltaic device. [0033] FIG. 3A is an exploded view of the temperature-drop delay section 103 of the sintering apparatus 100 shown in FIG. 2A as seen from bottom to top, to show structural details of the upper furnace 201. FIG. 3B is an exploded view of the temperature-drop delay section 103 of the sintering apparatus 100 shown in FIG. 2A as seen from top to bottom, to show structural details of the lower furnace 202. FIG. 3C is a sectional view of the temperature-drop delay section 103 of the sintering apparatus 100 shown in FIG. 2A, to show sectional structures of the upper furnace 201 and the lower furnace 202.

[0034] Generally, as shown in FIG. 3A and 3C, the upper furnace 201 comprises a housing, a pad, and a heating component. The pad is disposed in the housing. Specifically, the housing comprises an upper housing 301 , a left housing 302, a right housing 303, a rear housing 304, and a front housing 305. The left housing 302, the right housing 303, the rear housing 304, and the front housing 305 are respectively formed by a left edge, a right edge, a rear edge, and a front edge of the upper housing 301 extending downward. The upper housing 301 , the left housing 302, the right housing 303, the rear housing 304, and the front housing 305 enclose to form an accommodating cavity, used for accommodating the pad and the heating component. In an embodiment of this application, the pad is made of rockwool. The rockwool has adequate thermal insulation performance, so that heat generated by the heating component is kept in the accommodating cavity enclosed by the housing.

[0035] The pad in the upper furnace 201 comprises an upper pad 311 , a left pad 312, a right pad 313, a rear pad 314, a front pad 315, a separation pad 317, and an isolation pad 316. The upper pad 311 , the left pad 312, the right pad 313, the rear pad 314, and the front pad 315 are separately disposed on an inner wall of the accommodating cavity. In other words, the upper pad 311 is tightly attached to the upper housing 301 , the left pad 312 is tightly attached to the left housing 302, the left pad 312 is tightly attached to the left housing 302, the right pad 313 is tightly attached to the right housing 303, the rear pad 314 is tightly attached to the rear housing 304, and the front pad 315 is tightly attached to the front housing 305. The separation pad 317 is horizontally placed in the accommodating cavity, and is approximately disposed in parallel to the upper pad 311 . The separation pad 317 and the upper pad 311 are arranged at a distance, so that the upper pad 311 , the left pad 312, the right pad 313, the rear pad 314, the front pad 315, and the separation pad 317 enclose to form a separating accommodating cavity 321 ; and the left pad 312, the right pad 313, the rear pad 314, the front pad 315, and the separation pad 317 enclose to form a heating component accommodating cavity 322 provided with an opening below. The heating component is disposed in the heating component accommodating cavity 322. The isolation pad 316 is vertically disposed in the housing, to divide the separating accommodating cavity 321 and the heating component accommodating cavity 322 respectively into two independent separating accommodating cavities 321 and two independent heating component accommodating cavities 322. The two independent separating accommodating cavities 321 and the two independent heating component accommodating cavities 322 are arranged corresponding to the two transport channels 203.

[0036] The upper furnace 201 further comprises two gas introduction channels 331 used for enabling gas (for example, air) outside the housing to pass through the gas introduction channels 331 to enter the separating accommodating cavity 321 . One gas introduction channel 331 penetrates the left housing 302 and the left pad 312, and the other gas introduction channel 331 penetrates the right housing 303 and the right pad 313. When the temperature-drop delay section 103 operates, the heating component generates heat. The two gas introduction channels 331 introduce external gas into the separating accommodating cavity 321. The separation pad 317 is made of rockwool, and the rockwool is provided with holes. Therefore, gas can pass through the separation pad 317, and flows in the accommodating cavity enclosed by the housing. The flow of gas enables heat generated by the heating component to be more uniform in the accommodating cavity of the housing, to facilitate uniform heating of the photovoltaic device.

[0037] For the further details of the upper furnace 201 shown in FIG. 3A, the heating component of the upper furnace 201 comprises eight heating tubes 341 used for generating heat. Specifically, the eight heating tubes 341 are grouped into two groups. Each group comprises four heating tubes 341. The two groups of heating tubes 341 are separately disposed in the corresponding heating component accommodating cavities 322. A length direction of the heating tube 341 is arranged transversely with respect to a conveying direction of the conveyor belt. When the photovoltaic device is transported by the conveyor belt, one photovoltaic device sequentially passes through four heating tubes 341 , to enable the temperature of the photovoltaic device to rise. A heating temperature of the heating component is adjustable. In an example, an operator may adjust the magnitude of a current flowing through the heating tubes 341 , to adjust the heating temperature of the heating component.

[0038] As shown in FIG. 3A and 3C, generally, the structure of the lower furnace 202 is approximately similar to the structure of the upper furnace 201 . Specifically, the lower furnace 202 comprises a housing, a pad, and a heating component. The pad is disposed in the housing. The housing comprises a lower housing 351 , a left housing 352, a right housing 353, a rear housing 354, and a front housing 355. The left housing 352, the right housing 353, the rear housing 354, and the front housing 355 are respectively formed by a left edge, a right edge, a rear edge, and a front edge of the lower housing 351 extending upward. The lower housing 351 , the left housing 352, the right housing 353, the rear housing 354, and the front housing 355 enclose to form an accommodating cavity, used for accommodating the pad and the heating component. In an embodiment of this application, the pad is made of rockwool. The rockwool has adequate thermal insulation performance, so that heat generated by the heating component is kept in the accommodating cavity enclosed by the housing.

[0039] The pad in the lower furnace 202 comprises a lower pad 361 , a left pad 362, a right pad 363, a rear pad 364, a front pad 365, a separation pad 367, and an isolation pad 366. The lower pad 361 , the left pad 362, the right pad 363, the rear pad 364, and the front pad 365 are separately disposed on an inner wall of the accommodating cavity. In other words, the lower pad 361 is tightly attached to the lower housing 351 , the left pad 362 is tightly attached to the left housing 352, the left pad 362 is tightly attached to the left housing 352, the right pad 363 is tightly attached to the right housing 353, the rear pad 364 is tightly attached to the rear housing 354, and the front pad 365 is tightly attached to the front housing 355. The separation pad 367 is horizontally placed in the accommodating cavity, and is approximately disposed in parallel to the lower pad 361 . The separation pad 367 and the lower pad 361 are arranged at a distance, so that the lower pad 361 , the left pad 362, the right pad 363, the rear pad 364, the front pad 365, and the separation pad 367 enclose to form a separating accommodating cavity 371 ; and the left pad 362, the right pad 363, the rear pad 364, the front pad 365, and the separation pad 367 enclose to form a heating component accommodating cavity 372 provided with an opening below. The heating component is disposed in the heating component accommodating cavity 372. The isolation pad 366 is vertically disposed in the housing, to divide the separating accommodating cavity 371 and the heating component accommodating cavity 372 respectively into two independent separating accommodating cavities 371 and two independent heating component accommodating cavities 372. The two independent separating accommodating cavities 371 and the two independent heating component accommodating cavities 372 are arranged corresponding to the two transport channels 203.

[0040] The lower furnace 202 further comprises two gas introduction channels 381 used for enabling gas (for example, air) outside the housing to pass through the gas introduction channels 381 to enter the separating accommodating cavity 371 . One gas introduction channel 381 penetrates the left housing 352 and the left pad 362, and the other gas introduction channel 381 penetrates the right housing 353 and the right pad 363. When the temperature-drop delay section 103 operates, the heating component generates heat. The two gas introduction channels 381 introduce external gas into the separating accommodating cavity 371. The separation pad 367 is made of rockwool, and the rockwool is provided with holes. Therefore, gas can pass through the separation pad 367, and flows in the accommodating cavity enclosed by the housing. The flow of gas enables heat generated by the heating component to be more uniform in the accommodating cavity of the housing, to facilitate uniform heating of the photovoltaic device.

[0041] For the further details of the lower furnace 202 shown in FIG. 3B, the heating component of the lower furnace 202 comprises eight heating tubes 391 used for generating heat. Specifically, the eight heating tubes 391 are grouped into two groups. Each group comprises four heating tubes 391 . The two groups of heating tubes 391 are separately disposed in the corresponding heating component accommodating cavities 372. A length direction of the heating tube 391 is arranged transversely with respect to a conveying direction of the conveyor belt. When the photovoltaic device is transported by the conveyor belt, one photovoltaic device sequentially passes through four heating tubes 391 , to enable the temperature of the photovoltaic device to rise. A heating temperature of the heating component is adjustable. In an example, an operator may adjust the magnitude of a current flowing through the heating tubes 391 , to adjust the heating temperature of the heating component.

[0042] In addition, the lower furnace 202 further comprises eight quartz plates 392 and four conveyor belt support members 393. Specifically, each of the eight quartz plates 392 is arranged above a corresponding one of the eight heating tubes 391 , and is used for protecting the heating tube 391 , to prevent a foreign object from falling off the conveyor belt to avoid damaging the heating tube 391. The four conveyor belt support members 393 are grouped into two groups. Each group comprises two conveyor belt support members 393. The two groups of conveyor belt support members 393 are separately disposed in the corresponding heating component accommodating cavities 372. The conveyor belt support member 393 is arranged above the quartz plates 392 and has two ends abutting against the housing or pad, or connected to the housing or pad. A length direction of the conveyor belt support member 393 is arranged in the conveying direction of the conveyor belt, and a spacing between two conveyor belt support members 393 in each group is less than a width of the conveyor belt, to support the conveyor belt. [0043] In this way, the upper furnace 201 and the lower furnace 202 in the temperature-drop delay section 103 form a complete furnace. The furnace can apply the temperature-drop delay section heating temperature that is less than the sintering section sintering temperature and the sintering section preset temperature from above and below to the photovoltaic device that enters the furnace. The photovoltaic device that has undergone a temperature drop is then outputted from the temperature-drop delay section 103, and is subsequently conveyed into the cooling section 104. Ends of the rear housing 304 and the front housing 305 in the upper furnace 201 and the rear housing 354 and the front housing 355 in the lower furnace 202 in the conveying direction form separating plates, so that the upper furnace 201 and the lower furnace 202 of the temperaturedrop delay section 103 are separated from the sintering section 102 and the cooling section 104, to avoid heat dissipation.

[0044] It needs to be noted that although specific quantities of transport channels, heating tubes, quartz plates, conveyor belt support members, and the like are shown for the sintering apparatus in this application, a person skilled in the art may understand that any quantities of transport channels, heating tubes, and the like fall within the protection scope of this application. [0045] A person skilled in the art may further understand that although the heating component in this application is a heating tube, the heating component may be formed by other heating elements.

[0046] FIG. 4 is a schematic diagram of a distance-temperature relationship of a photovoltaic device in a sintering apparatus in the prior art. The horizontal coordinate shows a distance by which the photovoltaic device moves in the sintering apparatus in the length direction of the sintering apparatus, the vertical coordinate represents the temperature of the photovoltaic device, and the curve represents a temperature change of the photovoltaic device processed by the sintering apparatus in the prior art in the sintering apparatus. The sintering apparatus shown in FIG. 4 does not comprise a temperature-drop delay section. That is, the sintering apparatus shown in FIG. 4 comprises a drying section, a sintering section, and a cooling section that are sequentially disposed. When the photovoltaic device leaves the sintering section, the photovoltaic device is heated to a sintering section preset temperature. Subsequently, the photovoltaic device enters the cooling section, and is rapidly cooled to the cooling section preset temperature in the cooling section. According to existing requirements and in most cases, a photovoltaic device produced by using an existing sintering apparatus can meet a use requirement. However, the performance or performance parameters of a finished product of the photovoltaic device may be not adequate. For example, the solar energy conversion efficiency of converting solar energy into electrical energy of the photovoltaic device and an attenuation rate of the photovoltaic device during use are not optimal enough.

[0047] The applicant finds through observation that in the apparatus in the prior art, an inappropriate initial temperature-drop difference between the sintering section preset temperature when the photovoltaic device is outputted from the sintering section and the cooling section cooling temperature affects the use performance of the photovoltaic device. Specifically, the applicant finds through observation that when the photovoltaic device is outputted from the sintering section, the temperature (that is, the sintering section preset temperature) of the photovoltaic device is relatively high (for example, 700°C to 800°C). As a result, a temperature difference between the temperature of the photovoltaic device and the cooling section cooling temperature (for example, 40°C to 80°C) is excessively large. The photovoltaic device undergoes an excessively fast temperature drop when the photovoltaic device just enters the cooling section. The excessively fast temperature drop in this case leads to reduced solar energy conversion efficiency of the photovoltaic device during use. That is, during use, when the photovoltaic device converts received light energy into electrical energy, the solar energy conversion efficiency of the photovoltaic device is reduced. Correspondingly, during use, along with the use time, the attenuation performance of the photovoltaic device is relatively high, and the service life is relatively short.

[0048] FIG. 5 is a schematic diagram of a distance-temperature relationship of a photovoltaic device in the sintering apparatus 100 shown in FIG. 1 . The horizontal coordinate shows a distance by which the photovoltaic device moves in the sintering apparatus in the length direction of the sintering apparatus, the vertical coordinate represents the temperature of the photovoltaic device, and the solid curve represents a temperature change of the photovoltaic device processed by the sintering apparatus 100 shown in FIG. 1 in the sintering apparatus. In addition, the dotted curve in FIG. 5 represents a temperature change of the photovoltaic device processed by the sintering apparatus that does not comprise a temperaturedrop delay section shown in FIG. 4 in the sintering apparatus.

[0049] The sintering apparatus 100 shown in FIG. 5 comprises the temperaturedrop delay section 103. Specifically, the sintering apparatus 100 comprises the drying section 101 , the sintering section 102, the temperature-drop delay section 103, and the cooling section 104 that are sequentially disposed. In the embodiment of the sintering apparatus 100 shown in FIG. 5, the sintering section 102 is a multisection apparatus. The sintering section sintering temperature provided by the sintering section 102 is a multi-section temperature. Specifically, the sintering section 102 comprises three sintering units (that is, a first sintering unit, a second sintering unit, and a third sintering unit). Each sintering unit comprises one sintering section heating component. The first sintering unit comprises a sintering section heating component 501 , and provides a first sintering section sintering temperature. The second sintering unit comprises a second sintering section heating component 502, and provides a second sintering section sintering temperature. The third sintering unit comprises a third sintering section heating component 503, and provides a third sintering section sintering temperature. The first sintering section sintering temperature is less than or equal to the second sintering section sintering temperature, and the second sintering section sintering temperature is less than or equal to the third sintering section sintering temperature, so that the sintering section 102 continuously enables the photovoltaic device to undergo a temperature rise to continuously heat and sinter the photovoltaic device. The sintering section 102 is configured to enable the temperature of the photovoltaic device to reach the sintering section preset temperature when the photovoltaic device leaves the sintering section 102. In the sintering apparatus 100 shown in FIG. 5, the temperature-drop delay section 103 comprises one temperature-drop delay unit, providing one temperature-drop delay section heating temperature. The temperature-drop delay section 103 is configured to apply the temperature-drop delay section heating temperature that is less than the sintering section preset temperature to the photovoltaic device, so that the photovoltaic device undergoes a temperature drop at a relatively slow or reduced speed. The temperature-drop delay section 103 is further configured to enable the temperature of the photovoltaic device to reach an expected temperature-drop delay section preset temperature when the photovoltaic device leaves the temperature-drop delay section 103.

[0050] In the embodiment of the sintering apparatus 100 shown in FIG. 5, the cooling section 104 is a multi-section apparatus. The cooling section cooling temperature provided by the cooling section 104 is a multi-section temperature. Specifically, the cooling section 104 comprises three cooling units (that is, a first cooling unit, a second cooling unit, and a third cooling unit). Each cooling unit can provide one cooling temperature. Specifically, the first cooling unit can provide a first cooling unit cooling temperature. The second cooling unit can provide a second cooling unit cooling temperature. The third cooling unit can provide a third cooling unit cooling temperature. The first cooling unit cooling temperature is greater than or equal to the second cooling unit cooling temperature, and the second cooling unit cooling temperature is greater than or equal to the third cooling unit cooling temperature, so that the cooling section 104 continuously cools the photovoltaic device. The cooling section 104 is configured to enable the temperature of the photovoltaic device to be reduced to the cooling section preset temperature when the photovoltaic device leaves the cooling section 104. The cooling section preset temperature is less than the temperature-drop delay section preset temperature. In addition, the cooling temperature of each cooling unit is less than the temperature-drop delay section preset temperature. In the embodiment of the sintering apparatus 100 shown in FIG. 5, the cooling temperatures provided by the cooling units are equal, and are all approximately equal to the temperature of the environment in which the sintering apparatus 100 is located. Further, in the embodiment of the sintering apparatus 100 shown in FIG. 5, each cooling unit is provided with a fan 51 1 , 512, 513, to accelerate the heat dissipation of the photovoltaic device in the cooling section 104.

[0051] The sintering section preset temperature, the temperature-drop delay section preset temperature, and the cooling section preset temperature are all determined by the to-be-processed photovoltaic device, for example, are determined according to the use and type of the to-be-processed photovoltaic device. As discussed above, the applicant finds that if the photovoltaic device that is outputted by the sintering section and has a relatively high temperature undergoes a temperature drop at an excessively fast speed, this leads to reduced solar energy conversion efficiency of the photovoltaic device during use. It is found in this application that when the temperature drop speed is reduced in a high temperature section after the photovoltaic device leaves the sintering section, the solar energy conversion efficiency of the photovoltaic device during use can be improved. For different photovoltaic devices, specific values in the high temperature section following the sintering section are also different. Therefore, different photovoltaic devices have different temperature-drop delay section preset temperatures. Generally, the temperature-drop delay section preset temperature is greater than an average temperature of the sintering section preset temperature and the cooling section preset temperature. In some embodiments, the temperature-drop delay section preset temperature is greater than 80% of the sintering section preset temperature.

[0052] The temperature-drop delay section heating temperature is set to be greater than or equal to the temperature-drop delay section preset temperature. Although the temperature-drop delay section heating component 113 of the temperaturedrop delay section 103 is configured to perform heating at the temperature-drop delay section heating temperature, because the upper furnace 201 and the lower furnace 202 form a complete furnace, the furnace has particular heat dissipation, the environmental temperature in the furnace is less than the temperature-drop delay section heating temperature. Therefore, when the photovoltaic device leaves the temperature-drop delay section 103, the photovoltaic device can only be kept at the temperature-drop delay section preset temperature that is less than or equal to the temperature-drop delay section heating temperature.

[0053] After the temperature-drop delay section preset temperature is determined, the temperature-drop delay section heating temperature and a temperature-drop delay section length of the temperature-drop delay section 103 in the conveying direction are determined according to the to-be-processed photovoltaic device, the speed at which the photovoltaic device passes through the temperature-drop delay section 103, and the like. The temperature-drop delay section length is set to ensure that the photovoltaic device has sufficient time to produce a temperaturedrop effect in the temperature-drop delay section and the overall processing efficiency of the photovoltaic device is not affected. In some embodiments, the length of the temperature-drop delay section is 30% to 70% of the length of one sintering unit. After the temperature-drop delay section length is determined, the temperature-drop delay section preset temperature may be determined according to the temperature-drop delay section length and the temperature-drop delay section preset temperature, to enable the temperature of the photovoltaic device to be reduced to the temperature-drop delay section preset temperature after the photovoltaic device is conveyed through the length of the delay section.

[0054] The temperature drop rate is a ratio of a reduction value T of the temperature of the photovoltaic device after the photovoltaic device passes by a length L to the length L. Referring to the sintering apparatus 100 shown in FIG. 5, a temperature drop rate of the photovoltaic device in the temperature-drop delay section 103 is T1/L1 , and a temperature drop rate of the photovoltaic device in the first cooling unit is T2/L2. As shown by the dotted line in FIG. 5, if the temperaturedrop delay section 103 is not disposed as in FIG. 4, the photovoltaic device directly enters the cooling section 104 after being outputted by the sintering section 102. In this case, the temperature-drop speed in the conveying length L1 after the photovoltaic device leaves the sintering section 102 is greater than the temperature drop rate T1/L1 of the photovoltaic device in the temperature-drop delay section 103, because a temperature difference between the sintering section preset temperature when the photovoltaic device leaves the sintering section 102 and the cooling temperature provided by the cooling section 104 is greater than a temperature difference between the sintering section preset temperature when the photovoltaic device leaves the sintering section 102 and the temperature-drop delay section heating temperature provided by the temperature-drop delay section 103.

[0055] Further, in the embodiment shown in FIG. 5, the temperature-drop delay section 103 and the cooling section 104 are configured to enable the temperature drop rate of the photovoltaic device in the temperature-drop delay section 103 to be less than a temperature drop rate of the photovoltaic device in the cooling unit (the first cooling unit in this embodiment) closest to the temperature-drop delay section 103. That is, T1/L1 < T2/L2. Further, the temperature-drop delay section 103 is configured to enable an earlier temperature drop rate of the photovoltaic device to be less than a later temperature drop rate in the temperature-drop delay section 103. The temperature-drop delay section 103 may prevent the photovoltaic device from undergoing an excessively fast temperature drop in a high temperature section after the photovoltaic device is outputted from the sintering section, to implement thermal insulation for the photovoltaic device that leaves the sintering section 102. After the photovoltaic device is outputted from the sintering section 102, the time during which the sintered photovoltaic device is at a relatively high temperature is extended, which helps to improve the solar energy conversion efficiency of the produced photovoltaic device during use, reduce the attenuation performance of the photovoltaic device, and extend the service life of the photovoltaic device. In an example, for photovoltaic devices of the same use and type, compared with a photovoltaic device that does not pass through the temperature-drop delay section 103 during processing, the solar energy conversion efficiency of a photovoltaic device that passes through the temperaturedrop delay section 103 during processing can be improved by 5% to 10%, and the service life of the photovoltaic device can be extended by 1% to 2%.

[0056] In an example, during operation, for a photovoltaic device of a use and type, the sintering section sintering temperature (for example, the third sintering section sintering temperature) is 800°C, the sintering section preset temperature is 780°C, the temperature-drop delay section heating temperature is 750°C, the temperature-drop delay section preset temperature is 720°C, and the cooling section preset temperature (for example, a fourth cooling unit cooling temperature) is 60°C. That is, the temperature-drop delay section 103 can reduce the temperature of the photovoltaic device from 780°C to 720°C. Subsequently, the cooling section 104 reduces the temperature of the photovoltaic device from 720°C to 60°C.

[0057] In another example, for a photovoltaic device of a type, the drying section preset temperature is 300°C to 400°C, the sintering section preset temperature is 700°C to 900°C, the temperature-drop delay section heating temperature is 650°C to 750°C, and the cooling section preset temperature is 40°C to 80°C. The temperature-drop delay section length is 600 mm, and the speed at which the photovoltaic device passes through the temperature-drop delay section 103 is 11000 mm/minute.

[0058] In this application, a temperature difference between the sintering section preset temperature when the photovoltaic device is outputted by the sintering section 102 and a temperature (that is, the first cooling unit cooling temperature) applied at an input end of the cooling section 104 is divided into two relatively small, appropriate temperature-drop differences. The temperature-drop delay section 103 and the cooling section 104 are used to respectively reduce the temperature of the photovoltaic device in two different time periods. Because the photovoltaic device reaches a relatively high sintering section preset temperature when the photovoltaic device is outputted from the sintering section 102, an appropriate temperature-drop delay section heating temperature needs to be set for the temperature-drop delay section 103, to enable a temperature-drop difference between the sintering section preset temperature of the photovoltaic device outputted by the sintering section 102 and the temperature-drop delay section heating temperature of the temperature-drop delay section 103 to be within an appropriate range, so as to control a first section temperature-drop speed after the photovoltaic device is outputted from the sintering section 102. In the temperaturedrop delay section 103, the photovoltaic device undergoes a temperature drop at an appropriate temperature-drop speed, to enable the photovoltaic device to be reduced to an intermediate state temperature (that is, the temperature-drop delay section preset temperature) at an appropriate temperature-drop speed in the temperature-drop delay section 103, and the photovoltaic device reaches the intermediate state temperature when being outputted from the temperature-drop delay section 103 (that is, the temperature-drop delay section preset temperature). The temperature-drop delay section heating temperature to be applied is appropriately selected for the temperature-drop delay section 103, to reduce the temperature difference between the temperature when the photovoltaic device is outputted from the sintering section 102 and the temperature-drop delay section heating temperature provided by the temperature-drop delay section 103, thereby reducing a temperature-drop speed when the photovoltaic device is at a relatively high temperature after the sintering section 102 is outputted. In the cooling section 104, because the temperature-drop delay section 103 has reduced the temperature of the photovoltaic device at an appropriate temperature-drop speed, the photovoltaic device enters the cooling section 104 at a reduced temperature, to enable the temperature difference between the temperature of the photovoltaic device and the cooling temperature provided by the cooling section 104 to be reduced, thereby enabling the photovoltaic device to undergo a temperature drop at an appropriate temperature-drop speed in the cooling section 104, so as to be reduced to the cooling section preset temperature.

[0059] In this application, the temperature-drop delay section 103 and the cooling section 104 are disposed to cool the photovoltaic device outputted by the sintering section 102, and one temperature-drop difference of the photovoltaic device in the sintering apparatus in the prior art is divided into two appropriate, relatively small temperature-drop differences, to control an appropriate temperature-drop speed of the photovoltaic device from the sintering section preset temperature to the cooling section preset temperature, especially to control an appropriate temperature-drop speed when the photovoltaic device is in a relatively high temperature right after the photovoltaic device is outputted from the sintering section, so as to improve the solar energy conversion efficiency of the photovoltaic device during use and reduce the attenuation performance of the photovoltaic device.

[0060] It further needs to be noted that although the sintering section 102 in this application comprises three sintering units, and the cooling section 104 comprises four cooling units, a person skilled in the art may understand that the sintering section 102 comprising at least two sintering units and the cooling section 104 comprising at least two cooling units both fall within the protection scope of this application.

[0061] Although only some features of the present application are illustrated and described herein, those skilled in the art would have made various improvements and modifications. Therefore, it should be understood that the appended claims intend to cover all the foregoing improvements and changes that fall within the substantial spirit and scope of the present application.

Claims

What is claimed is:

1 .A sintering apparatus (100), used for processing a photovoltaic device, characterized in that the sintering apparatus comprises: a sintering section (102), wherein the sintering section (102) is provided with a sintering section heating component (112), the sintering section heating component (112) provides a sintering section sintering temperature, and the sintering section (102) is configured to heat and sinter a photovoltaic device conveyed into the sintering section (102) at the sintering section sintering temperature, and is configured to enable the photovoltaic device to reach a sintering section preset temperature when the photovoltaic device leaves the sintering section

(102); a temperature-drop delay section (103), wherein the temperature-drop delay section (103) is disposed behind the sintering section (102) in a conveying direction of the photovoltaic device, the temperature-drop delay section (103) is provided with a temperature-drop delay section heating component (113), the temperature-drop delay section heating component (113) provides a temperature-drop delay section heating temperature, the temperature-drop delay section (103) is configured to apply the temperature-drop delay section heating temperature to the photovoltaic device conveyed from the sintering section (102) into the temperature-drop delay section

(103), and the temperature-drop delay section heating temperature is less than the sintering section preset temperature; and a cooling section (104), wherein the cooling section (104) is disposed behind the temperature-drop delay section (103) in the conveying direction of the photovoltaic device, the cooling section (104) provides a cooling temperature, the cooling section (104) is configured to cool the photovoltaic device conveyed from the temperature-drop delay section (103) into the cooling section (104) at the cooling temperature, and is configured to enable the photovoltaic device to reach a cooling section preset temperature when the photovoltaic device leaves the cooling section

(104), and the temperature-drop delay section heating temperature is greater than the cooling temperature.

22

2. The sintering apparatus (100) as claimed in claim 1 , characterized in that the sintering section sintering temperature provided by the sintering section

(102) is a multi-section temperature.

3. The sintering apparatus (100) as claimed in claim 1 , characterized in that the sintering section (102) comprises at least two sintering units, and each of the at least two sintering units provides one sintering section sintering temperature; and the temperature-drop delay section (103) comprises one temperature-drop delay unit, and the temperature-drop delay unit provides one temperature-drop delay section heating temperature.

4. The sintering apparatus (100) as claimed in claim 1 , characterized in that the temperature-drop delay section (103) is configured to enable the photovoltaic device to reach a temperature-drop delay section preset temperature when the photovoltaic device leaves the temperature-drop delay section (103), and the temperature-drop delay section preset temperature is greater than an average temperature of the sintering section preset temperature and the cooling section preset temperature.

5. The sintering apparatus (100) as claimed in claim 4, characterized in that the temperature-drop delay section preset temperature is greater than 80% of the sintering section preset temperature.

6. The sintering apparatus (100) as claimed in claim 4, characterized in that the cooling section (104) comprises at least two cooling units, and the photovoltaic device that leaves the cooling section (104) is sequentially conveyed through the at least two cooling units, wherein the temperature-drop delay section (103) is configured to enable a temperature drop rate of the photovoltaic device in the temperature-drop delay section (103) to be less than a temperature drop rate of the photovoltaic device in the cooling unit closest to the temperature-drop delay section (103).

7. The sintering apparatus (100) as claimed in claim 6, characterized in that the temperature-drop delay section (103) has a temperature-drop delay section length in the conveying direction, wherein the temperature-drop delay section length and the temperature-drop delay section heating temperature are set to enable the temperature drop rate of the photovoltaic device in the temperature-drop delay section (103) to be less than the temperature drop rate of the photovoltaic device in the cooling unit closest to the temperature-drop delay section (103).

8. The sintering apparatus (100) as claimed in claim 7, characterized in that the temperature-drop delay section heating temperature is greater than or equal to the temperature-drop delay section preset temperature.

9. The sintering apparatus (100) as claimed in claim 3, characterized in that the length of the temperature-drop delay section (103) is 30% to 70% of the length of one of the at least two sintering units.

10. The sintering apparatus (100) as claimed in claim 1 , characterized in that the temperature-drop delay section (103) comprises an upper furnace (201 ), a lower furnace (202), and a transport channel (203), wherein the heating component is disposed between the upper furnace (201 ) and the lower furnace (202), and a spacing is provided between at least a part of the upper furnace (201 ) and at least a part of the lower furnace (202), to form the transport channel (203) used for allowing the photovoltaic device to pass through; and each of two ends of the upper furnace (201 ) and the lower furnace (202) in the conveying direction is provided with a separating plate, so that the upper furnace (201 ) and the lower furnace (202) are separated from the sintering section (102) and the cooling section (104).