Device and method for utilizing waste heat of tail gas of photovoltaic cell pyrolysis equipment

Abstract

The invention provides a photovoltaic cell pyrolysis equipment tail gas waste heat utilization device and method, and belongs to the technical field of environmental protection. The device comprises a gas distribution system, a waste heat utilization system, an electric auxiliary heating system, a pyrolysis system and a tail gas treatment system. Wherein the gas distribution system, the waste heat utilization system, the electric auxiliary heating system and the pyrolysis system are sequentially connected to form a first passage for low-temperature flue gas circulation; the pyrolysis system, the waste heat utilization system and the tail gas treatment system are sequentially connected to form a second passage for high-temperature tail gas circulation; and in the waste heat utilization system, low-temperature flue gas of the gas distribution system and high-temperature tail gas or heat of the pyrolysis system can be subjected to heat exchange. The waste heat of the outlet of the photovoltaic cell pyrolysis equipment is introduced into the heat storage tank to be stored, the atmosphere needed in the photovoltaic cell pyrolysis process can be heated in the waste heat utilization system, and therefore the waste heat in the photovoltaic cell pyrolysis process is fully utilized.

Description

Technical Field

[0001] The present disclosure belongs to the field of environmental protection technology, and specifically relates to a device and method for utilizing waste heat from tail gas of a photovoltaic cell pyrolysis device. Background Art

[0002] As an important part of clean energy, the photovoltaic industry has been developing rapidly. However, large-scale photovoltaic modules are also facing the problem of retirement. Green treatment and resource utilization have become issues that need to be addressed urgently.

[0003] The valuable components of waste photovoltaic modules primarily include aluminum frames, silicon wafers, glass, solder ribbons, and junction boxes. Currently, the disassembly and recycling technologies for junction boxes and aluminum frames are relatively mature for the recycling of waste photovoltaic modules. However, the separation of laminates composed of glass, cells, backsheets, EVA, and solder ribbons remains a significant challenge. Currently, the main methods for separating these laminates include physical separation, chemical dissolution, and high-temperature pyrolysis. High-temperature pyrolysis is simple to operate, requires no chemicals, produces no waste liquid, is easily scalable, and is highly efficient, making it promising for industrial application in the future. Therefore, research into the resource utilization of cells in laminates after high-temperature pyrolysis may offer greater prospects for the recycling of waste photovoltaic modules. However, high-temperature pyrolysis is currently primarily a laboratory research method, with no mature continuous industrial equipment available. Furthermore, research on the purification and treatment of pyrolysis exhaust gases has received relatively little attention.

[0004] The pyrolysis process requires heating the flue gas to 400°C to 800°C, then maintaining this temperature for 2-24 hours. Finally, the photovoltaic panels and flue gas are cooled. The huge temperature difference will cause the photovoltaic panels to crack or even break due to internal stress. Therefore, the photovoltaic panels and flue gas need to be cooled slowly during the cooling process. However, a large amount of heat will be wasted during the cooling process. Summary of the Invention

[0005] The present disclosure aims to solve at least one of the technical problems existing in the prior art and provide a device and method for utilizing waste heat from tail gas of a photovoltaic cell pyrolysis device.

[0006] In one aspect of the present disclosure, a device for utilizing waste heat from tail gas of a photovoltaic cell pyrolysis device is provided, the device comprising: a gas distribution system, a waste heat utilization system, an electric auxiliary heating system, a pyrolysis system, and a tail gas treatment system; wherein,

[0007] The gas distribution system, the waste heat utilization system, the electric auxiliary heating system, and the pyrolysis system are connected in sequence to form a first passage for the circulation of low-temperature flue gas;

[0008] The pyrolysis system, the waste heat utilization system, and the tail gas treatment system are connected in sequence to form a second passage for the circulation of high-temperature tail gas;

[0009] In the waste heat utilization system, the low-temperature flue gas of the gas distribution system and the high-temperature exhaust gas or heat of the pyrolysis system can exchange heat.

[0010] Optionally, the waste heat utilization system includes at least one heat exchanger.

[0011] Optionally, the waste heat utilization system includes a first heat exchanger and a second heat exchanger; wherein,

[0012] The first heat exchanger and the second heat exchanger both have a flue gas inlet and a flue gas outlet for low-temperature flue gas circulation, and an exhaust gas inlet and an exhaust gas outlet for high-temperature exhaust gas circulation; wherein,

[0013] The flue gas inlet of the second heat exchanger is connected to the gas distribution system, and the flue gas outlet is connected to the flue gas inlet of the first heat exchanger;

[0014] The tail gas outlet of the second heat exchanger is connected to the tail gas treatment system, and the tail gas inlet is connected to the tail gas outlet of the first heat exchanger;

[0015] The flue gas outlet of the first heat exchanger is connected to the electric auxiliary heating system, and the tail gas inlet is connected to the pyrolysis system.

[0016] Optionally, the smoke inlet and the smoke outlet are connected to form a smoke channel, and the exhaust gas inlet and the exhaust gas outlet are connected to form an exhaust gas channel;

[0017] The flue gas channel and the exhaust gas channel can exchange heat.

[0018] Optionally, at least one of the air distribution system and the waste heat utilization system, the waste heat utilization system and the electric auxiliary heating system, the electric auxiliary heating system and the pyrolysis system, the pyrolysis system and the waste heat utilization system, and the waste heat utilization system and the exhaust gas treatment system is provided with a valve and a power source.

[0019] Optionally, the valve and the power source are both connected to a PLC control system.

[0020] Optionally, the outsides of the reactors in the electric auxiliary heating system, the waste heat utilization system and the pyrolysis system are all provided with a thermal insulation layer.

[0021] Optionally, a thermal insulation layer is provided on the outside of the connecting pipes between the gas distribution system, the waste heat utilization system, the electric auxiliary heating system, the reactor in the pyrolysis system and the tail gas treatment system.

[0022] Another aspect of the present disclosure provides a method for utilizing waste heat from tail gas of a photovoltaic cell pyrolysis device, the method comprising:

[0023] The mixed low-temperature flue gas prepared by the gas distribution system is introduced into the waste heat utilization system;

[0024] When the temperature of the reactor in the pyrolysis system needs to be lowered, the heat of the reactor and the photovoltaic panel is passed into the waste heat utilization system; or when the high-temperature exhaust gas of the pyrolysis system needs to be discharged, the high-temperature flue gas is passed into the waste heat utilization system;

[0025] The low-temperature flue gas and the high-temperature exhaust gas or heat exchange heat in the waste heat utilization system;

[0026] The low-temperature flue gas after heat exchange is further heated by the electric auxiliary heating system and then enters the pyrolysis system, and the high-temperature exhaust gas after heat exchange further enters the exhaust gas treatment system.

[0027] Optionally, when the low-temperature flue gas and the high-temperature exhaust gas or heat exchange heat in the waste heat utilization system, the contact time between the high-temperature exhaust gas and the low-temperature flue gas can be controlled by a PLC control system.

[0028] The present disclosure proposes a device and method for utilizing the waste heat of tail gas from photovoltaic cell pyrolysis equipment. The device includes: a gas distribution system, a waste heat utilization system, an electric auxiliary heating system, a pyrolysis system, and an exhaust gas treatment system; wherein the gas distribution system, the waste heat utilization system, the electric auxiliary heating system, and the pyrolysis system are connected in sequence to form a first passage for the circulation of low-temperature flue gas; the pyrolysis system, the waste heat utilization system, and the exhaust gas treatment system are connected in sequence to form a second passage for the circulation of high-temperature exhaust gas; in the waste heat utilization system, the low-temperature flue gas of the gas distribution system can exchange heat with the high-temperature exhaust gas or heat of the pyrolysis system. The present disclosure introduces the waste heat from the outlet of the photovoltaic cell pyrolysis equipment into a heat storage tank for storage, and the waste heat utilization system can heat the atmosphere required for the photovoltaic cell pyrolysis process, thereby fully utilizing the waste heat from the photovoltaic cell pyrolysis process. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic structural diagram of a device for utilizing waste heat from tail gas of a photovoltaic cell pyrolysis device according to an embodiment of the present disclosure;

[0030] Figure 2 This is a flowchart of a method for utilizing waste heat from tail gas of a photovoltaic cell pyrolysis device according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0031] To enable those skilled in the art to better understand the technical solutions of the present disclosure, the present disclosure is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to illustrate the present disclosure and are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present disclosure.

[0032] like Figure 1 As shown, one aspect of the present disclosure provides a device 100 for utilizing waste heat from exhaust gas of a photovoltaic cell pyrolysis device, comprising: a gas distribution system 110, a waste heat utilization system 120, an electric auxiliary heating system 130, a pyrolysis system 140, and an exhaust gas treatment system 150; wherein, the gas distribution system 110, the waste heat utilization system 120, the electric auxiliary heating system 130, and the pyrolysis system 140 are connected in sequence to form a first passage for the circulation of low-temperature flue gas, and the pyrolysis system 140, the waste heat utilization system 120, and the exhaust gas treatment system 150 are connected in sequence to form a second passage for the circulation of high-temperature exhaust gas; in this way, the low-temperature flue gas flows from the gas distribution system through the first passage into the waste heat utilization system, and the high-temperature exhaust gas flows from the pyrolysis system through the second passage into the exhaust gas treatment system. In the waste heat utilization system 120, the low-temperature flue gas of the gas distribution system 110 and the high-temperature exhaust gas or heat of the pyrolysis system 140 can exchange heat.

[0033] In this embodiment, a waste heat utilization device is designed to fully utilize the waste heat generated during the pyrolysis of the photovoltaic panels to heat the flue gas before testing, saving energy and costs. It also allows for a slow cooling of the photovoltaic panels, preventing cracks caused by internal stress due to excessive temperatures.

[0034] It should be noted that, in some preferred embodiments, the waste heat from the outlet of the photovoltaic cell pyrolysis equipment can also be introduced into a heat storage tank for storage and used to heat the atmosphere required for the photovoltaic cell pyrolysis process, thereby making full use of the waste heat from the photovoltaic cell pyrolysis process.

[0035] It should be further noted that this embodiment does not impose any specific restrictions on the waste heat utilization system; any system capable of achieving heat transfer and heat exchange, such as a heat exchanger, will suffice. It should be understood that when a waste heat utilization system employs a heat exchanger, the number of heat exchangers included is not specifically limited, and may be one, two, or three heat exchangers, etc., without specific limitation.

[0036] For example, Figure 1As shown, the waste heat utilization system 120 includes a first heat exchanger 121 and a second heat exchanger 122; wherein, the first heat exchanger 121 has a first flue gas inlet and a first flue gas outlet for the circulation of low-temperature flue gas, and a first exhaust gas inlet and a second exhaust gas outlet for the circulation of high-temperature exhaust gas; the second heat exchanger 122 has a second flue gas inlet and a second flue gas outlet for the circulation of low-temperature flue gas, and a second exhaust gas inlet and a second exhaust gas outlet for the circulation of high-temperature exhaust gas; the second flue gas inlet of the second heat exchanger 122 is connected to the gas distribution system 110, and the second flue gas outlet is connected to the first flue gas inlet of the first heat exchanger 121; the second exhaust gas outlet of the second heat exchanger 122 is connected to the exhaust gas treatment system 150, the second exhaust gas inlet is connected to the first exhaust gas outlet of the first heat exchanger 121, the first flue gas outlet of the first heat exchanger 121 is connected to the electric auxiliary heating system 10, and the first exhaust gas inlet is connected to the pyrolysis system 140.

[0037] For further information, please refer to Figure 1 The first flue gas inlet and the first flue gas outlet of the first heat exchanger are connected to form a first flue gas channel, and the first exhaust gas inlet and the first exhaust gas outlet are connected to form a first exhaust gas channel; the first flue gas channel and the first exhaust gas channel can exchange heat.

[0038] Similarly, please continue to refer to Figure 1 The second flue gas inlet and the second flue gas outlet of the second heat exchanger are connected to form a second flue gas channel, and the second exhaust gas inlet and the second exhaust gas outlet are connected to form a second exhaust gas channel; the second flue gas channel and the second exhaust gas channel can exchange heat.

[0039] It should be understood that in the first heat exchanger, the first flue gas channel and the first exhaust gas channel should not be connected, and the low-temperature flue gas and the high-temperature exhaust gas should exchange heat in their respective channels by relying on the channel walls. Similarly, in the second heat exchanger, the second flue gas channel and the second exhaust gas channel should not be connected, and the low-temperature flue gas and the high-temperature exhaust gas should exchange heat in their respective channels by relying on the channel walls.

[0040] It should also be understood that the exhaust gas inlet, exhaust gas outlet, flue gas inlet, and flue gas outlet of the second heat exchanger constitute a heat exchange path. Low-temperature flue gas enters the second heat exchanger through the inlet, exchanging heat with exhaust gas entering the second heat exchanger through the exhaust gas inlet. The low-temperature flue gas gradually heats up, while the high-temperature exhaust gas gradually cools down. Subsequently, the heated flue gas exits the second heat exchanger through the flue gas outlet, and the cooled low-temperature exhaust gas exits the second heat exchanger through the exhaust gas outlet.

[0041] It should be further noted that a valve and a power source are installed in at least one of the connections between the gas distribution system and the waste heat utilization system, the waste heat utilization system and the electric auxiliary heating system, the electric auxiliary heating system and the pyrolysis system, the pyrolysis system and the waste heat utilization system, or the waste heat utilization system and the exhaust gas treatment system. In other words, valves and power sources can be installed on the connecting pipes between any two systems to control the flow of the corresponding connecting pipes, thereby further controlling the flow of low-temperature flue gas or high-temperature exhaust gas.

[0042] For example, Figure 1 As shown, a first connecting pipe is provided between the gas distribution system 110 and the second heat exchanger 122, and a first valve 161 and a first power source 162 are provided on the first connecting pipe; when the mixed flue gas compounded by the gas distribution system 110 needs to be heated, the first valve 161 and the first power source 162 are controlled to open, and the low-temperature flue gas is passed into the second heat exchanger 122.

[0043] Further, if Figure 1 As shown, a second connecting pipe is provided between the first heat exchanger 121 and the electric auxiliary heating system 130, and a second valve 163 is provided on the second connecting pipe; a third connecting pipe is provided between the electric auxiliary heating system 130 and the pyrolysis system 140, and a second power source 164 is provided on the third connecting pipe.

[0044] Of course, it should be understood that in other preferred embodiments, a second power source may be provided on the second connecting pipe, and a second valve may be provided on the third connecting pipe, that is, corresponding valves and power sources may be provided on each connecting pipe.

[0045] Furthermore, if Figure 1 As shown, a fourth connecting pipe is provided between the pyrolysis system 140 and the first heat exchanger 121, and a third valve 165 and a third power source 166 are provided on the fourth connecting pipe. When the high-temperature exhaust gas from the pyrolysis system 140 needs to be discharged or the reactor in the pyrolysis system 140 needs to be cooled, the third valve 165 and the third power source 166 are controlled to open, allowing the heat from the high-temperature exhaust gas or the reactor and the photovoltaic panel to be passed into the first heat exchanger 121. In other words, when the high-temperature flue gas flowing through the reactor needs to be discharged, the heat from the high-temperature flue gas is passed into the first and second heat exchangers by controlling the start and stop of the third valve and the third power source. When the reactor needs to be cooled, the heat from the reactor and the photovoltaic panel is passed into the first and second heat exchangers by controlling the start and stop of the third valve and the third power source, thereby slowly lowering the catalyst temperature while using the heat to heat the components of the initial mixed gas.

[0046] Furthermore, if Figure 1As shown, a fifth connecting pipe is provided between the second heat exchanger 122 and the exhaust gas treatment system 150 , and a fourth valve 167 and a fourth power source 168 are provided on the fifth connecting pipe.

[0047] It should be noted that the power source in this embodiment can be a pump. Of course, in other preferred embodiments, a fan can also be used as long as it can transport low-temperature flue gas or high-temperature exhaust gas.

[0048] Furthermore, in other preferred embodiments, the first valve, second valve, third valve, fourth valve, first power source, second power source, third power source, and fourth power source mentioned above are all connected to a PLC control system. That is, the start and stop of each valve and each power source are automatically controlled by the PLC control system to achieve the transportation of high-temperature exhaust gas and low-temperature flue gas, as well as the effective utilization of high-temperature exhaust gas. For example, when the mixed flue gas compounded by the flue gas generation system needs to be heated, the cold flue gas is passed into the second heat exchanger by controlling the start and stop of the first valve and the first power source; the cold flue gas is heated by exchanging heat with the high-temperature flue gas flowing out of the reactor in the pyrolysis system and the heat generated when the reactor and catalyst are cooled. During the detection process, the flue gas needs to be compounded with a certain concentration of water vapor. The desalted water is introduced into the first heat exchanger, and partially heated by heat exchange heating. After being heated by the electric auxiliary heating system, the water vapor is formed and introduced into the reactor system.

[0049] It should also be understood that controlling the induced draft fan air volume through a PLC control system can regulate the contact time between the high-temperature exhaust gas and the low-temperature flue gas water to achieve temperature consistency. For example, when the pyrolysis of photovoltaic panels in the reactor requires a large amount of flue gas, it is difficult to achieve complete heat exchange and coverage in a short period of time by controlling the induced draft fan air volume through PLC. In this case, a temperature difference between the high-temperature exhaust gas and the low-temperature flue gas can be allowed based on the flue gas volume demand.

[0050] This embodiment uses an electric heating auxiliary system to heat the high-temperature flue gas, further raising the temperature until it reaches the set test temperature for photovoltaic panel pyrolysis, and then introduces it into the pyrolysis system to test and evaluate the performance of the photovoltaic panel under the flue gas conditions. The low-temperature exhaust gas, after being cooled by the heat exchanger, passes through the flue gas purification and emission system and is discharged into the atmosphere.

[0051] It should be noted that the electric auxiliary heating system, the waste heat utilization system and the reactor in the pyrolysis system of this embodiment are all provided with an insulation layer outside to prevent heat loss.

[0052] It should also be noted that the connecting pipes between the gas distribution system, the waste heat utilization system, the electric auxiliary heating system, the reactor in the pyrolysis system, and the tail gas treatment system in this embodiment are provided with an insulation layer. In other words, the insulation layer provided on the outside of each of the aforementioned connecting pipes prevents heat loss and enhances the preheating effect.

[0053] It should be noted that this embodiment does not specifically limit the material of the thermal insulation layer, for example, thermal insulation cotton.

[0054] In this embodiment, the pyrolysis system, first heat exchanger, second heat exchanger, flue gas purification and exhaust system, and their connecting pipes form a first pathway. Heat from the high-temperature flue gas in the pyrolysis system is transferred through the first and second heat exchangers, and the low-temperature gas at the heat exchanger outlet is introduced into the flue gas purification and exhaust system. The pyrolysis system, gas distribution system, first heat exchanger, second heat exchanger, auxiliary electric heating, fan, valves, and their connecting pipes form a second pathway. By controlling the opening and closing of valves and pumps, the low-temperature flue gas from the flue gas generation system is introduced into the two-stage heat exchanger. The heated gas at the heat exchanger outlet is introduced into the auxiliary electric heating system. After a second precise heating process by electric heating, the high-temperature flue gas, which has reached the set test temperature for photovoltaic panel pyrolysis, is introduced into the pyrolysis system.

[0055] Compared with the previous flue gas heating system that completely relied on the electric heating system, the waste heat utilization device provided in this embodiment can make full use of the waste heat of the exhaust gas, transfer the heat of the high-temperature flue gas in the pyrolysis system through the heat exchanger, and introduce the low-temperature gas at the outlet of the heat exchanger into the flue gas purification and emission system. At the same time, the low-temperature flue gas in the flue gas generation system is introduced into the two-stage heat exchanger, and the heated gas at the outlet of the heat exchanger is introduced into the electric heating auxiliary system. After the second precise heating by electric heating, the high-temperature flue gas that reaches the set test temperature for photovoltaic panel pyrolysis is introduced into the pyrolysis system, achieving the effect of energy saving and consumption reduction.

[0056] like Figure 2 As shown, another aspect of the present disclosure provides a method S200 for utilizing waste heat from tail gas of a photovoltaic cell pyrolysis device, comprising the following steps S210 to S240:

[0057] S210, introducing the mixed low-temperature flue gas prepared by the gas distribution system into the waste heat utilization system.

[0058] Specifically, please combine Figure 1 As shown in the figure, during the pyrolysis process of the photovoltaic panel, the flue gas generation system realizes the precise allocation of gas components through gas preparation and gas mixing according to the test requirements. The low-temperature flue gas of the gas distribution system enters from the left side of the second heat exchanger and flows from the right end to the first heat exchanger after heat exchange.

[0059] It should be understood that the flue gas temperature after being heated by the preheating system may not meet the pyrolysis temperature requirements. Therefore, it is necessary to use the electric heating auxiliary system to perform a secondary heating to meet the pyrolysis temperature requirements. In other words, the heated low-temperature flue gas is further circulated to the electric auxiliary heating system for heating treatment.

[0060] S220. When the reactor in the pyrolysis system needs to be cooled, the heat of the reactor and the photovoltaic panel is passed into the waste heat utilization system. Alternatively, when the high-temperature exhaust gas of the pyrolysis system needs to be discharged, the high-temperature flue gas is passed into the waste heat utilization system.

[0061] Specifically, when the high-temperature flue gas circulating in the reactor in the pyrolysis system needs to be discharged, the heat of the high-temperature flue gas is passed into the first heat exchanger and the second heat exchanger by controlling the start and stop of the valve and the pump; when the reactor needs to be cooled, the heat of the reactor and the photovoltaic panel is passed into the first heat exchanger and the second heat exchanger by controlling the start and stop of the valve and the pump, thereby slowly lowering the catalyst temperature while using the heat to heat the initial mixed gas components.

[0062] S230. The low-temperature flue gas and the high-temperature exhaust gas or heat are heat-exchanged in a waste heat utilization system.

[0063] Specifically, the high-temperature exhaust gas after pyrolysis is introduced into the first heat exchanger and the second heat exchanger to exchange heat with the low-temperature flue gas in the heat exchanger. The air volume of the induced draft fan is controlled by PLC, and the contact time of the high-temperature exhaust gas and the low-temperature flue gas water is regulated to achieve temperature consistency.

[0064] It should be understood that when the pyrolysis of photovoltaic panels in the reactor requires a large amount of flue gas, it is difficult to achieve complete heat exchange and coverage in a short period of time by controlling the induced draft fan air volume through PLC and regulating the contact time between the high-temperature exhaust gas and the low-temperature flue gas. In this case, the flue gas volume demand shall prevail, and a temperature difference between the high-temperature exhaust gas and the low-temperature flue gas shall be allowed.

[0065] S240. The low-temperature flue gas after heat exchange is further heated by the electric auxiliary heating system and then enters the pyrolysis system. The high-temperature exhaust gas after heat exchange further enters the exhaust gas treatment system.

[0066] Specifically, flue gas reaching pyrolysis temperature is introduced into the pyrolysis system, where the photovoltaic panels within the system undergo pyrolysis treatment. Furthermore, exhaust gas, after heat exchange in the heat exchanger, is discharged through the flue gas purification and exhaust system.

[0067] The following is a further description of the device for utilizing waste heat from tail gas of photovoltaic cell pyrolysis equipment with reference to specific embodiments:

[0068] Example 1

[0069] A factory has a batch of photovoltaic panels that need to be processed. The pyrolysis temperature is 450℃ and the flue gas flow rate is 50m 3 / h, with an O2 gas content of 10uL / L and the remaining components being air. A single plate should be kept at high temperature for at least 4h.

[0070] During the pyrolysis process of the photovoltaic panels, the flue gas generation system prepares the test flue gas with an O2 gas content of 10uL / L and the remaining components supplemented by air according to the test requirements, and introduces the flue gas into the second heat exchanger to achieve initial temperature increase.

[0071] After the initial heating, the flue gas temperature reaches 180℃, and after the secondary heat exchange, the flue gas reaches 280℃. With the help of the electric heating auxiliary system, the secondary heating is carried out to reach 450℃. After that, the PLC control system issues an instruction, and the electric heating auxiliary system is adjusted to the low temperature gear to realize the insulation function. If the temperature drops, the PLC control system will turn on the heating gear of the electric heating auxiliary system to ensure the stability of the flue gas temperature.

[0072] The flue gas at 450°C is introduced into the pyrolysis system to perform pyrolysis on the photovoltaic panels in the pyrolysis system. The entire pyrolysis residence time is about 4 hours.

[0073] The high-temperature exhaust gas at 450°C after the test is introduced into the first heat exchanger and the second heat exchanger to exchange heat with the low-temperature flue gas in the heat exchanger. The air volume of the induced draft fan is controlled by the PLC control system, and the contact time of the high-temperature exhaust gas and the low-temperature flue gas is adjusted to 5 minutes, thereby achieving sufficient heat exchange between the low-temperature flue gas and the high-temperature exhaust gas in the two paths.

[0074] After heat exchange in the heat exchanger, the exhaust gas temperature drops to 150°C and is discharged through the flue gas purification and exhaust system.

[0075] Compared with the previous flue gas heating system that relied entirely on electric heating systems, this preheating and utilization device can fully utilize the waste heat of the exhaust gas, achieving the effect of energy saving and consumption reduction.

[0076] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present disclosure, and the present disclosure is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present disclosure, and such modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A device for utilizing waste heat from tail gas of photovoltaic cell pyrolysis equipment, characterized in that: The device includes: a gas distribution system, a waste heat utilization system, an electric auxiliary heating system, a pyrolysis system and an exhaust gas treatment system; wherein, The gas distribution system, the waste heat utilization system, the electric auxiliary heating system, and the pyrolysis system are connected in sequence to form a first passage for the circulation of low-temperature flue gas; The pyrolysis system, the waste heat utilization system, and the exhaust gas treatment system are connected in sequence to form a second passage for the circulation of high-temperature exhaust gas; In the waste heat utilization system, the low-temperature flue gas of the gas distribution system and the high-temperature exhaust gas or heat of the pyrolysis system can exchange heat.

2. The device according to claim 1, characterized in that The waste heat utilization system includes at least one heat exchanger.

3. The device according to claim 2, characterized in that The waste heat utilization system includes a first heat exchanger and a second heat exchanger; wherein, The first heat exchanger and the second heat exchanger both have a flue gas inlet and a flue gas outlet for low-temperature flue gas circulation, and an exhaust gas inlet and an exhaust gas outlet for high-temperature exhaust gas circulation; wherein, The flue gas inlet of the second heat exchanger is connected to the gas distribution system, and the flue gas outlet is connected to the flue gas inlet of the first heat exchanger; The tail gas outlet of the second heat exchanger is connected to the tail gas treatment system, and the tail gas inlet is connected to the tail gas outlet of the first heat exchanger; The flue gas outlet of the first heat exchanger is connected to the electric auxiliary heating system, and the tail gas inlet is connected to the pyrolysis system.

4. The device according to claim 3, characterized in that The smoke inlet and the smoke outlet are connected to form a smoke channel, and the exhaust gas inlet and the exhaust gas outlet are connected to form an exhaust gas channel; The flue gas channel and the exhaust gas channel can exchange heat.

5. The device according to claim 1, characterized in that At least one of the air distribution system and the waste heat utilization system, the waste heat utilization system and the electric auxiliary heating system, the electric auxiliary heating system and the pyrolysis system, the pyrolysis system and the waste heat utilization system, and the waste heat utilization system and the exhaust gas treatment system is provided with a valve and a power source.

6. The device according to claim 5, characterized in that The valve and the power source are both connected to a PLC control system.

7. The device according to any one of claims 1 to 6, characterized in that The outsides of the reactors in the electric auxiliary heating system, the waste heat utilization system and the pyrolysis system are all provided with a thermal insulation layer.

8. The device according to any one of claims 1 to 6, characterized in that The gas distribution system, the waste heat utilization system, the electric auxiliary heating system, the reactor in the pyrolysis system and the connecting pipes between the tail gas treatment system are all provided with insulation layers on the outside.

9. A method for utilizing waste heat from tail gas of photovoltaic cell pyrolysis equipment, characterized in that: The method comprises: The mixed low-temperature flue gas prepared by the gas distribution system is introduced into the waste heat utilization system; When the temperature of the reactor in the pyrolysis system needs to be lowered, the heat from the reactor and the photovoltaic panel is passed into the waste heat utilization system; or, when the high-temperature exhaust gas from the pyrolysis system needs to be discharged, the high-temperature flue gas is passed into the waste heat utilization system; The low-temperature flue gas and the high-temperature exhaust gas or heat exchange heat in the waste heat utilization system; The low-temperature flue gas after heat exchange is further heated by the electric auxiliary heating system and then enters the pyrolysis system, and the high-temperature exhaust gas after heat exchange further enters the exhaust gas treatment system.

10. The method according to claim 9, characterized in that When the low-temperature flue gas and the high-temperature tail gas or heat exchange heat in the waste heat utilization system, the contact time between the high-temperature tail gas and the low-temperature flue gas can be controlled by the PLC control system.

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