Anode material sintering waste heat power generation system

Abstract

The invention discloses a positive electrode material sintering waste heat power generation system, and relates to the technical field of waste heat utilization of a positive electrode material production process. The waste heat power generation system comprises a roller kiln, a first power generation assembly, a first smoke exhaust pipe and a second smoke exhaust pipe. The first heat exchanger is close to the first turbine; the first smoke exhaust pipe is used for heating the first heat exchanger, and the second smoke exhaust pipe is used for heating the second heat exchanger. In this way, the flue gas is utilized in a gradient mode, the high-temperature flue gas heats the high-temperature first medium, and the low-temperature flue gas heats the low-temperature first medium. Compared with direct centralized heating without flue gas grading, the positive electrode material sintering waste heat power generation system provided by the invention can better utilize flue gas heat, can generate more power generation capacity and reduce the power utilization cost of positive electrode material production, and the flue gas is lower in temperature and smaller in influence on the environment when being finally discharged.

Description

Technical Field

[0001] The present invention relates to the technical field of utilization of waste heat from sintering of new energy cathode materials, and particularly relates to a waste heat power generation system for sintering cathode materials. Background Art

[0002] Sintering of lithium-ion battery cathode materials is a key process in the production of lithium-ion batteries. It promotes physical and chemical bonding between cathode material particles through high temperature to form a dense polycrystalline sintered body, thereby improving the conductivity, energy density, and cycle life of the cathode material.

[0003] The sintering process of cathode materials generally uses a roller hearth kiln device for continuous production for 24 hours. The lithium-containing mixed material in pots is gradually heated to 750 - 950 °C by electric heating, and then gradually cooled to room temperature through oxygen supply, air suction, and air blowing. During the cooling process of the sintered body, the main components of the flue gas generated are the air sent in, followed by a small amount of CO2 and dust generated by the sintering reaction. During the cooling process of the sintered material, the exhaust gas in the cooling section of the roller hearth kiln generates flue gas at 200 - 700 °C in different sections. The current production process generally reduces the temperature to about 200 °C by mixing with cold air, and then directly discharges it into the atmosphere through an induced draft fan. According to statistics, the power consumption for the production of each ton of ternary cathode material is about 5400 kwh, and the energy consumption of the sintering process accounts for as high as 60%. The heat of a large amount of cooling flue gas generated during the cooling process of the sintered body is currently directly discharged without effective utilization, which not only wastes energy but also has a certain degree of heat island effect on the environment around the factory. Summary of the Invention

[0004] The main object of the present invention is to propose a waste heat power generation system for sintering cathode materials, aiming to fully utilize the heat of the flue gas in the roller hearth kiln for power generation, reduce the production electricity cost, and be beneficial to environmental protection.

[0005] To achieve the above object, the waste heat power generation system proposed by the present invention includes a roller hearth kiln; a first exhaust pipe and a second exhaust pipe, the first exhaust pipe and the second exhaust pipe are respectively connected to the roller hearth kiln to introduce the flue gas in the roller hearth kiln and make the temperature of the flue gas in the first exhaust pipe higher than the temperature of the flue gas in the second exhaust pipe; a first power generation assembly, forming a first circuit for the flow of a first medium, the first circuit having a first heat exchanger and a second heat exchanger; each heat exchanger can, after absorbing the heat of the flue gas in each exhaust pipe, heat the first medium from a liquid state to a steam state and drive a first turbine to generate electricity; wherein, along the direction of the first circuit, the first heat exchanger is close to the first turbine, the second heat exchanger is far from the first turbine, and the flue gas in the first exhaust pipe is used to heat the first heat exchanger, and the flue gas in the second exhaust pipe is used to heat the second heat exchanger.

[0006] In one embodiment, a connecting pipe is further included, and the connecting pipe is connected between the first exhaust pipe and the second exhaust pipe, so that the flue gas with a higher temperature can heat the heat exchanger with a lower temperature after heating the heat exchanger with a higher temperature.

[0007] In one embodiment, a third heat exchanger and a third exhaust pipe are further included; in the direction of the first loop, the third heat exchanger is arranged between the first heat exchanger and the second heat exchanger, and the third exhaust pipe is arranged between the first exhaust pipe and the second exhaust pipe, and the flue gas in the third exhaust pipe is used to heat the third heat exchanger;

[0008] Two connecting pipes are provided, one of the connecting pipes is arranged between the first exhaust pipe and the third exhaust pipe, and the other connecting pipe is arranged between the third exhaust pipe and the second exhaust pipe.

[0009] In one embodiment, a desuperheating pipeline assembly is further included, and the desuperheating pipeline assembly is arranged outside the connecting pipe and / or outside the exhaust pipe.

[0010] In one embodiment, a second power generation assembly is further included, and the second power generation assembly forms a second loop for the second medium to flow. The second power generation assembly can absorb the waste heat of the first medium passing through the first turbine in the steam state and / or the heat of the first medium in the liquid state, so as to change the second medium in the second power generation loop from the liquid state to the steam state and drive the second turbine to generate electricity; the boiling point of the second medium is lower than the boiling point of the first medium.

[0011] In one embodiment, the second power generation assembly has a preheating pipe section, and the preheating pipe section can absorb the waste heat of the first medium passing through the first turbine in the steam state; and / or, the second power generation assembly has a heating pipe section, and the heating pipe section can absorb the heat of the first medium in the liquid state.

[0012] In one embodiment, the first power generation assembly includes a hot water pipe section connected between the two heat exchangers, and the hot water pipe section is connected with a hot water branch, and a regulating valve is arranged on the hot water branch.

[0013] In one embodiment, the first turbine and the second turbine are coaxial to drive the same generator to generate electricity.

[0014] In one embodiment, a blower is further included, and the blower is arranged around the roller kiln and close to the second exhaust pipe to introduce cold air to the second exhaust pipe in the roller kiln, so as to reduce the temperature of the flue gas in the second exhaust pipe.

[0015] In one embodiment, a smoke guiding assembly is connected to the end of the second smoke exhaust pipe. The smoke guiding assembly includes a smoke extractor fan and a smoke exhaust pipe for extracting the smoke in the second smoke exhaust pipe.

[0016] The technical solution of the present invention makes cascade utilization of the waste heat of the smoke in the roller hearth kiln. The high-temperature smoke is introduced into the first smoke exhaust pipe and the low-temperature smoke is introduced into the second smoke exhaust pipe, so that the first smoke exhaust pipe is used to heat the first heat exchanger close to the first turbine, and the second smoke exhaust pipe is used to heat the second heat exchanger far from the first turbine; that is to say, the high-temperature smoke heats the high-temperature first medium, and the low-temperature smoke heats the low-temperature first medium. The technical solution of the present invention makes full use of the low-temperature smoke, so that the temperature of the exhausted smoke is lower and the impact on the environment is smaller. Since the high-temperature smoke can make the first medium boil more quickly, more steam can be generated, and thus more electricity can be generated. And, since more electricity is generated, it means that more heat of the smoke is utilized, so the temperature of the smoke when finally discharged is lower, that is, the impact on the environment is smaller. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0018] Figure 1 It is a schematic structural diagram of an embodiment of a positive electrode material sintering waste heat power generation system provided by the present invention;

[0019] Figure 2 It is a schematic structural diagram of another embodiment of a positive electrode material sintering waste heat power generation system provided by the present invention.

[0020] Explanation of the reference numerals in the drawings:

[0021] 1. Roller hearth kiln; 2. Smoke exhaust pipe; 21. First smoke exhaust pipe; 22. Second smoke exhaust pipe; 23. Third smoke exhaust pipe; 3. First power generation assembly; 31. First circuit; 311. Heat exchanger; 3111. First heat exchanger; 3112. Second heat exchanger; 3113. Third heat exchanger; 312. First turbine; 313. Hot water pipeline; 3131. Hot water branch; 3132. Hot water flow control valve; 3133. Hot water branch; 314. Condensate tank; 315. Steam pipeline; 316. Steam turbine exhaust pipeline; 4. Connecting pipe; 5. Desuperheating pipeline assembly; 51. Spray desuperheater; 52. Front isolation valve; 53. Water filter; 54. Control valve; 55. Rear isolation valve; 6. Second power generation assembly; 61. Second circuit; 611. Second turbine; 612. Preheating pipe section; 613. Heating pipe section; 614. Liquid storage tank; 615. Organic working medium steam pipeline; 616. Organic working medium exhaust pipeline; 7. Blower; 8. Smoke extraction assembly; 81. Induced draft fan; 9. Flue gas bypass; 91. Bypass butterfly valve.

[0022] The realization, functional features and advantages of the object of the present invention will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0024] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0025] In addition, if the embodiments of the present invention involve descriptions such as "first" and "second", the descriptions of "first", "second", etc. are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel scenarios. Taking "A and / or B" as an example, it includes scenario A, or scenario B, or the scenario where both A and B are satisfied simultaneously. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on what can be achieved by those of ordinary skill in the art. When the combination of technical solutions results in contradictions or cannot be achieved, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0026] Please refer to Figure 1 and Figure 2 , the present invention provides a waste heat power generation system for sintering positive electrode materials. This waste heat power generation system for sintering positive electrode materials is applicable to the utilization of the waste heat of the flue gas generated in the cooling process after the positive electrode materials of new energy batteries are heated by a roller hearth kiln electric furnace.

[0027] Please refer to Figure 1 , this waste heat power generation system for sintering positive electrode materials includes a roller hearth kiln 1, a first exhaust pipe 21, and a second exhaust pipe 22. A cavity is formed inside the roller hearth kiln 1 to facilitate accommodating the material to be sintered. Exemplarily, the roller hearth kiln 1 is used for sintering the positive electrode materials of lithium batteries. The roller hearth kiln 1 is in the shape of a long strip flue. The roller hearth kiln 1 successively has a preheating zone, a firing zone, and a cooling zone, that is, the cooling zone of the roller hearth kiln 1 can discharge flue gas at different temperatures along its extending direction. Therefore, flue gas at different temperatures can be discharged at different positions inside the roller hearth kiln 1.

[0028] The first exhaust pipe 21 and the second exhaust pipe 22 are respectively connected to the roller hearth kiln 1. The first exhaust pipe 21 is used to introduce the high-temperature flue gas inside the roller hearth kiln 1, and the second exhaust pipe 22 is used to introduce the low-temperature flue gas inside the roller hearth kiln 1.

[0029] Please refer to Figure 1, the sintering waste heat power generation system for the positive electrode material further includes a first power generation component 3. The first power generation component 3 forms a first circuit 31 for the flow of a first medium. Among them, the first medium can preferably be water, and of course, other liquids can also be selected as long as they can be converted into a steam state at high temperatures. The first circuit 31 has a first heat exchanger 3111 and a second heat exchanger 3112. After the first medium in the first circuit 31 passes through the first heat exchanger 3111 and the second heat exchanger 3112, it absorbs the heat of the flue gas in the first exhaust pipe 21 and the second exhaust pipe 22, converting the first medium from a liquid state to a steam state. When the first medium in the steam state passes through the first turbine 312 (the first turbine 312 can be a radial turbine or an axial turbine, as long as it can convert the kinetic energy of the steam into rotational mechanical energy with the highest efficiency), the first turbine 312 rotates under the drive of the steam, thereby driving the generator to generate electricity.

[0030] Please refer to Figure 1 , along the direction of the first circuit 31, the first heat exchanger 3111 is close to the first turbine 312, and the second heat exchanger 3112 is far from the first turbine 312. It can be understood that under normal working conditions, the first medium should be in a steam state before reaching the first turbine 312. Then, during the flow of the first medium, the closer it is to the first turbine 312, the higher the temperature, and the farther it is from the first turbine 312, the lower the temperature. Therefore, under normal working conditions, the temperature of the first heat exchanger 3111 is higher than that of the second heat exchanger 3112.

[0031] As can be seen from the above, the temperature of the first exhaust pipe 21 is higher than that of the second exhaust pipe 22, and the temperature of the first heat exchanger 3111 is higher than that of the second heat exchanger 3112. Therefore, if the first exhaust pipe 21 and the second exhaust pipe 22 are further arranged so that the first exhaust pipe 21 heats the first heat exchanger 3111 and the second exhaust pipe 22 heats the second heat exchanger 3112; then, the high-temperature exhaust pipe heats the high-temperature heat exchanger, and the low-temperature exhaust pipe heats the low-temperature heat exchanger; that is, the high-temperature flue gas heats the high-temperature first medium, and the low-temperature flue gas heats the low-temperature first medium.

[0032] An embodiment of the present invention provides a waste heat power generation system for sintering cathode materials. The power generation system includes a roller hearth kiln 1, a first exhaust pipe 21, a second exhaust pipe 22, and a first power generation component 3. The first exhaust pipe 21 and the second exhaust pipe 22 are respectively connected to the roller hearth kiln 1 to introduce the flue gas in the cooling section of the roller hearth kiln 1 and make the temperature of the flue gas in the first exhaust pipe 21 higher than that in the second exhaust pipe 22. The first loop 31 of the first power generation component 3 has a first heat exchanger 3111 and a second heat exchanger 3112. Among them, along the direction of the first loop 31, the first heat exchanger 3111 is close to the first turbine 312, and the second heat exchanger 3112 is far from the first turbine 312. The first exhaust pipe 21 is used to heat the first heat exchanger 3111, and the second exhaust pipe 22 is used to heat the second heat exchanger 3112. In the embodiment of the present invention, by setting the first exhaust pipe 21 and the second exhaust pipe 22 on the roller hearth kiln 1, and making the first exhaust pipe 21 for discharging high-temperature flue gas and the second exhaust pipe 22 for discharging low-temperature flue gas; at the same time, by setting the first heat exchanger 3111 and the second heat exchanger 3112 on the first power generation loop, and making the first heat exchanger 3111 pass through high-temperature first medium and the second heat exchanger 3112 pass through low-temperature first medium; and, the first exhaust pipe 21 is used to heat the first heat exchanger 3111, and the second exhaust pipe 22 is used to heat the second heat exchanger 3112. Thus, the high-temperature flue gas in the first exhaust pipe 21 is used to heat the high-temperature first medium, and the low-temperature flue gas in the second exhaust pipe 22 is used to heat the low-temperature first medium.

[0033] Please refer to Figure 1 , for the convenience of understanding the effect of the present invention, take "the overall flue gas temperature in the roller hearth kiln 1 is about 400 °C, and after temperature grading, it becomes high-temperature flue gas of 600 °C and low-temperature flue gas of 200 °C" as an example for illustration. In the embodiment of the present invention, the high-temperature flue gas of 600 °C is introduced into the first exhaust pipe 21, and the low-temperature flue gas of 200 °C is introduced into the second exhaust pipe 22. Then, the low-temperature flue gas of 200 °C preheats the first medium, and then the high-temperature flue gas of 600 °C heats the first medium. Compared with the existing method of directly heating the first medium with flue gas at 400 °C, ① in the embodiment of the present invention, the low-temperature flue gas of 200 °C is also utilized, so that the temperature of the exhausted flue gas is lower and the environmental impact is smaller; ② the high-temperature flue gas of 600 °C in the embodiment of the present invention can make the first medium boil more quickly, thus generating more steam and more electricity. ③ Since more electricity is generated, it means that more heat of the flue gas is utilized, so the temperature of the flue gas at the final emission is lower, that is, the environmental impact is smaller.

[0034] Therefore, the waste heat power generation system for sintering cathode materials provided by the embodiment of the present invention is more conducive to power generation and more environmentally friendly than the existing related technologies.

[0035] In some embodiments, please refer to Figure 1, the sintering waste heat power generation system for the positive electrode material further includes a connecting pipe 4. The connecting pipe 4 can be provided with one or multiple. The number of the connecting pipes 4 is related to the number of the exhaust pipes. If two exhaust pipes are provided, only one connecting pipe 4 can be provided (please refer to Figure 1 ); if two exhaust pipes are provided, two connecting pipes 4 can be provided (please refer to Figure 2 ), or three can be provided, as long as it can connect between the two exhaust pipes.

[0036] Please refer to Figure 1 . The connecting pipe 4 connects between any two exhaust pipes. Specifically, when connecting, one end of the connecting pipe 4 can be connected to the tail of the exhaust pipe with a relatively higher temperature, and the other end can be connected to the front of the exhaust pipe with a relatively lower temperature. Among them, the "tail" can be understood as the position where the flue gas in the exhaust pipe enters the outlet of the corresponding heat exchanger; the "front" can be understood as the position where the flue gas in the exhaust pipe enters the inlet of the corresponding heat exchanger.

[0037] In an embodiment, please refer to Figure 1 . The number of the connecting pipes 4 is one. The connecting pipe 4 is connected between the first exhaust pipe 21 and the second exhaust pipe 22. Specifically, one end of the connecting pipe 4 is connected to the tail of the first exhaust pipe 21, and the other end is connected to the front of the second exhaust pipe 22. After the flue gas in the first exhaust pipe 21 heats the first heat exchanger 3111, the temperature is still higher than the temperature of the flue gas in the second heat exchanger 3112. Then the connecting pipe 4 passes the flue gas in the first exhaust pipe 21 into the second exhaust pipe 22, so that the temperature of the flue gas in the second exhaust pipe 22 increases, which is beneficial to heating the second heat exchanger 3112 and also beneficial to the utilization of the flue gas waste heat, and thus beneficial to power generation.

[0038] In another embodiment, please refer to Figure 2 . The number of the connecting pipes 4 is two. The waste heat power generation system further includes a third heat exchanger 3113 and a third exhaust pipe 23. In the direction of the first loop 31, the third heat exchanger 3113 is arranged between the first heat exchanger 3111 and the second heat exchanger 3112, and the third exhaust pipe 23 is arranged between the first exhaust pipe 21 and the second exhaust pipe 22. The third exhaust pipe 23 is used to heat the third heat exchanger 3113. One of the connecting pipes 4 is arranged between the first exhaust pipe 21 and the third exhaust pipe 23, and the other connecting pipe 4 is arranged between the third exhaust pipe 23 and the second exhaust pipe 22. In this way, the flue gas introduced from the first exhaust pipe 21 is utilized three times. Specifically, the flue gas in the first exhaust pipe 21 first heats the first heat exchanger 3111, then heats the third heat exchanger 3113, and finally heats the second heat exchanger 3112. The flue gas introduced from the third exhaust pipe 23 section is utilized twice. Specifically, the flue gas in the third exhaust pipe 23 first heats the third heat exchanger 3113 and then heats the second heat exchanger 3112.

[0039] Therefore, the arrangement of two connecting pipes 4, and the corresponding arrangements of three smoke exhaust pipes and three heat exchangers, compared with the arrangement of one connecting pipe 4, make the flue gas temperature grades in the roller hearth kiln 1 finer. Correspondingly, it is more conducive to improving the utilization rate of flue gas waste heat and reducing the impact on the environment.

[0040] In some embodiments, please refer to Figure 1 and Figure 2 , the waste heat power generation system for sintering the positive electrode material further includes a desuperheating pipeline assembly 5. The desuperheating pipeline assembly 5 includes a spray desuperheater 51 which is arranged outside the connecting pipe 4 to spray and desuperheat the connecting pipe 4.

[0041] It can be understood that when the waste heat power generation system fails and cannot convert heat into electrical energy output, at this time, the temperature in the smoke exhaust pipe 2 is very high, so it is necessary to cool the flue gas in the smoke exhaust pipe 2. Since the temperatures of the flue gas in the first smoke exhaust pipe 21 and the third smoke exhaust pipe 23 are relatively high, and the temperature in the second smoke exhaust pipe 22 is relatively low, therefore, the spray desuperheater 51 is arranged outside the connecting pipe 4 to spray and cool the connecting pipe 4. Further, the spray desuperheater 51 is arranged on the connecting pipe 4. Since the temperatures of the flue gas in the first smoke exhaust pipe 21 and the third smoke exhaust pipe 23 are relatively high, when the spray desuperheater 51 sprays the outer wall of the connecting pipe 4, the water will directly vaporize when encountering the high-temperature flue gas, and this vaporization effect can instantaneously reduce the temperature of the flue gas in the connecting pipe 4, thereby reducing the amount of cold air required at the tail end of the second smoke exhaust pipe 22, and thus reducing the power consumption and required power of the cold air blower at this place.

[0042] Please refer to Figure 1 , the desuperheating pipeline assembly 5 further includes a front isolation valve 52, a water filter 53, a regulating valve 54 and a rear isolation valve 55. The front isolation valve 52 is used to connect the water pipe to introduce external water. When the waste heat power generation system for sintering the positive electrode material fails to utilize the heat of the flue gas in the smoke exhaust pipe 2, the temperature of the flue gas can be quickly reduced by spray desuperheating, avoiding overheating of the induced draft fan 81 arranged at the tail end of the smoke exhaust pipe 2. When the desuperheating spray vaporizes, it absorbs a large amount of heat from the flue gas, significantly reducing the flue gas temperature, and can reduce the increase in flue gas volume caused by mixing with cold air.

[0043] In the embodiments of the present invention, by arranging the desuperheating pipeline assembly 5 on the connecting pipe 4 and / or the smoke exhaust pipe 2 to reduce the temperature of the flue gas in the smoke exhaust pipe 2, on the one hand, it reduces the amount of cold air required before the flue gas in the smoke exhaust pipe 2 is discharged into the atmosphere, and reduces the increase in flue gas volume caused by mixing with cold air; on the other hand, it reduces the impact on the environment caused by the too high temperature of the flue gas when it is discharged into the atmosphere.

[0044] In some embodiments, please refer to Figure 1 and Figure 2, a flue gas bypass 9 is connected to the first exhaust pipe 21 and / or the second exhaust pipe 22 and / or the third exhaust pipe 23, and a bypass butterfly valve 91 is provided on the flue gas bypass 9. When the whole system is working normally, the bypass butterfly valve 91 is closed. When a failure occurs in the first circuit 31 and / or the second circuit 61, or when the first heat exchanger 3111 and / or the second heat exchanger 3112 and / or the third heat exchanger 3113 need to be overhauled, the bypass butterfly valve 91 is opened so that the high-temperature flue gas in the exhaust pipe 2 can be discharged and cooled through the subsequent temperature reduction pipeline assembly 5.

[0045] In some embodiments, please refer to Figure 1 , the sintering waste heat power generation system for the positive electrode material further includes a second power generation assembly 6. The second power generation assembly 6 forms a second circuit 61 for the second medium to flow. The second power generation assembly 6 can absorb the waste heat of the first medium passing through the first turbine 312 in the steam state and / or the heat of the first medium in the liquid state, so as to change the second medium in the second circuit 61 from the liquid state to the steam state and pass through the second turbine 611 to generate electricity; the boiling point of the second medium is lower than that of the first medium. Regarding the selection of the first medium and the second medium, water can be used as the first medium, and an organic substance with a low boiling point and non-flammable can be used as the second medium.

[0046] Among them, in order to enable the second power generation assembly 6 to absorb the heat in the first power generation assembly 3, the first circuit 31 and the second circuit 61 can be set to partially overlap. This partial overlap can be understood as the two circuits approaching each other so that the heat of the first circuit 31 with a higher temperature can be transferred to the second circuit 61 with a lower temperature.

[0047] In the embodiment of the present invention, by setting the second power generation assembly 6 and the boiling point of the second medium being lower than that of the first medium, the heat in the first circuit 31 can be absorbed by the second circuit 61. After the second circuit 61 absorbs heat, the second medium changes from a liquid state to a steam state, thereby driving the second turbine 611 to generate electricity. Therefore, the setting of the second power generation assembly 6 enables the remaining heat of the first circuit 31 to be utilized, which is more conducive to power generation.

[0048] In some embodiments, please refer to Figure 1, the second power generation component 6 has a preheating pipe section 612 which can absorb the waste heat of the first medium in the steam state passing through the first turbine 312. It can be understood that after the first medium passes through the first turbine 312, its own heat will rapidly decrease, but will not be reduced to zero, that is, it still has low-temperature heat. Therefore, in order to make full use of this part of the remaining low-temperature heat, the pipeline section in the first loop 31 connecting to the rear end of the first turbine 312 (the rear end can be understood as the part after the first turbine 312 along the flow direction of the first medium) overlaps with the preheating pipe section 612 of the second loop 61, so that heat exchange can occur between this pipeline section of the first loop 31 and the preheating pipe section 612 of the second loop 61, which is beneficial to converting the second medium from the liquid state to the steam state and contributing to the power generation of the second loop 61.

[0049] In some embodiments, please refer to Figure 1 , the second power generation component 6 has a heating pipe section 613 which can absorb the heat of the first medium in the liquid state. It can be understood that after the first medium in the first loop 31 is heated, its temperature is relatively high. Using this part of the water to heat the second loop 61 can quickly convert the second medium from the liquid state to the steam state, which is beneficial to the power generation of the second loop 61.

[0050] In some embodiments, please refer to Figure 1 , in order to improve the stability of the second loop 61, that is, to avoid dangers such as explosion caused by the sudden conversion of the second medium in the second loop 61 from the liquid state to the steam state.

[0051] First, use the waste heat of the first medium in the steam state in the first loop 31 to heat the preheating pipe section 612 of the second loop 61, and then use the high-temperature liquid first medium in the first loop 31 to heat the heating pipe section 613 of the second loop 61. In this way, the second medium in the second loop 61 is first preheated and then heated into the steam state.

[0052] In some embodiments, please refer to Figure 1 , the first power generation component 3 includes a hot water pipe section 313 connected between two heat exchangers 311. The hot water pipe section 313 is connected with a hot water branch 3131, and a hot water flow dividing valve 3132 is arranged on the hot water branch 3131. By adjusting the opening degree of the hot water flow dividing valve 3132, a part of the preheated hot water is diverted through the hot water branch 3133 to the first heat exchanger 3111, and water vapor is generated after heat exchange with the high-temperature flue gas. This hot water branch 3131 is used to heat the second loop 61. Specifically, this hot water branch 3131 is used to heat the heating pipe section 613 of the second loop 61 to convert the second medium from the liquid state to the steam state. And, through the setting of the hot water flow dividing valve 3132, the heat supply to the second loop 61 is regulated. On the one hand, it can enable the second power generation component 6 to generate electricity normally, and on the other hand, it reduces the waste of heat.

[0053] In some embodiments, referring to Figure 1 , the first turbine 312 and the second turbine 611 are coaxial to drive the same generator to generate electricity. In this way, the setting and space occupation of the generator are reduced, thereby reducing costs.

[0054] In some embodiments, referring to Figure 1 , the waste heat power generation system further includes a blower 7. It can be understood that if the overall temperature in the roller hearth kiln 1 is relatively high, although the flue gas temperature in the second exhaust pipe 22 is relatively low, after heating the second heat exchanger 3112, its flue gas temperature is still relatively high compared to the emission standard temperature in environmental protection. Therefore, it still needs to be cooled before the flue gas in the second exhaust pipe 22 is discharged.

[0055] In the embodiment of the present invention, a blower 7 is arranged around the roller hearth kiln 1 and close to the second exhaust pipe 22 to introduce cold air to the second exhaust pipe 22 in the roller hearth kiln 1. On the one hand, the flue gas temperature in the second exhaust pipe 22 is reduced, which helps the flue gas to meet the emission standard when discharged into the atmosphere; on the other hand, according to the parameter control requirements for the sintering of the positive electrode material in the roller hearth kiln 1, the intake and exhaust volumes are adjusted through a control valve.

[0056] In some embodiments, referring to Figure 1 , two blowers 7 can be arranged, and one of them is for standby.

[0057] In some embodiments, referring to Figure 1 , the end of the second exhaust pipe 22 is connected with a smoke guiding assembly 8. The smoke guiding assembly 8 includes a smoke exhaust fan 81 for extracting the flue gas in the second exhaust pipe 22 and the corresponding valve body. Two smoke exhaust fans 81 can be arranged, and one of them is for standby. Through the arrangement of the smoke guiding assembly 8 in the embodiment of the present invention, the flue gas inside the waste heat power generation system can be discharged, enabling the system to operate normally.

[0058] The entire operating principle of the positive electrode material sintering waste heat power generation system will be elaborated below. Taking water as the first medium and an organic working fluid with a lower boiling point and non-flammable as the second medium as an example for illustrative explanation.

[0059] Regarding Figure 1 the flow direction of the flue gas in : First, the high-temperature flue gas in the roller hearth kiln 1 enters the first exhaust pipe 21, and the low-temperature flue gas in the roller hearth kiln 1 enters the second exhaust pipe 22; then, the flue gas in the first exhaust pipe 21 passes through the connecting pipe 4, so that the flue gas converges in the second exhaust pipe 22, and the tail end of the second exhaust pipe 22 is discharged to the atmosphere under the action of the smoke exhaust fan 81.

[0060] Regarding Figure 1Flow direction of the first medium (water) in: First, cold water is first heated in the second heat exchanger 3112 to become high-temperature hot water. The high-temperature hot water is divided into two parts at the hot water pipeline 313. One part of the high-temperature hot water enters the first heat exchanger 3111 through the hot water branch 3133. The high-temperature hot water is heated in the first heat exchanger 3111 to become water vapor. The water vapor enters the first turbine 312 through the steam pipeline 315 to generate electricity. The temperature decreases and the humidity increases, making it unable to be utilized by the first turbine. The water vapor discharged from the first turbine 312 passes through the steam turbine exhaust pipe 316 to preheat the second medium in the preheating pipe section 612 of the second circuit 61. After preheating, the temperature of the water vapor decreases and condenses into water, which then collects in the condensate tank 314. The condensate water is pressurized by the water pump and then flows back to the second heat exchanger 3112. The other part of the high-temperature hot water passes through the hot water branch 3131 and enters the second heat exchanger 613 to heat the second medium in the second circuit 61, turning the second working fluid from liquid to steam. The temperature of the hot water decreases and becomes cold water, which then merges with the water flowing out of the condensate tank 314. The cold water flows back to the second heat exchanger 3112; this cycle repeats.

[0061] Regarding Figure 1 and Figure 2 Flow direction of the second medium (organic working fluid) in: First, the cooled organic working fluid in the liquid storage tank 614 first passes through the preheating pipe section 612, and the temperature of the organic working fluid rises to become high-temperature organic working fluid. Then the high-temperature organic working fluid passes through the heating pipe section 613 to become organic working fluid in a steam state. The organic working fluid in a steam state drives the second turbine 611 to generate electricity after passing through the organic working fluid steam pipeline 615. Then, the organic working fluid in a steam state passes through the organic working fluid exhaust pipe 616. Finally, the organic working fluid in a steam state is cooled and flows back to the liquid storage tank 614; this cycle repeats.

[0062] Regarding Figure 2 Flow direction of the flue gas in: First, the high-temperature flue gas in the roller hearth kiln 1 enters the first exhaust pipe 21, the low-temperature flue gas in the roller hearth kiln 1 enters the second exhaust pipe 22, and the medium-temperature flue gas in the roller hearth kiln 1 enters the third exhaust pipe 23. Then, the flue gas in the first exhaust pipe 21 enters the third exhaust pipe 232 through the connecting pipe 4, causing the flue gas to converge in the third exhaust pipe 23. The flue gas in the third exhaust pipe 23 enters the second exhaust pipe 22 through the connecting pipe 4, causing the flue gas to converge in the second exhaust pipe 22. The tail end of the second exhaust pipe 22 is discharged to the atmosphere under the action of the induced draft fan 81.

[0063] Regarding Figure 2Flow direction of the first medium (water) in [the system]: First, cold water is first heated in the second heat exchanger 3112 to become medium-temperature hot water. The medium-temperature hot water enters the third heat exchanger 311 and is reheated to become high-temperature hot water. The high-temperature hot water is divided into two parts in the hot water pipe section 313. One part of the high-temperature hot water enters the first heat exchanger 3111 through the hot water branch 3133. The high-temperature hot water is continuously heated in the first heat exchanger 3111 to become water vapor. The water vapor passes through the steam pipeline 315, then passes through the first turbine 312 to generate electricity. Then, it passes through the steam turbine exhaust pipeline 316 to preheat the preheating pipe section 612 in the second loop 61. After that, the temperature of the water vapor decreases. Then, it becomes cold water in the condenser 314, and this cold water flows back to the second heat exchanger 3112. The other part of the high-temperature hot water passes through the hot water branch 3131 and heats the heating pipe section 613 in the second loop 61. The temperature of this hot water decreases and becomes cold water. Then, it converges with the water flowing out of the condensate tank 314, and this cold water flows back to the second heat exchanger 3112; and so on in a cycle.

[0064] The above is only an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformation made under the technical concept of the present invention by using the content of the specification and drawings of the present invention, or any direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A sintering waste heat power generation system for a cathode material, characterized in that, Comprising: A roller hearth kiln, A first exhaust pipe and a second exhaust pipe, the first exhaust pipe and the second exhaust pipe are respectively connected to the roller hearth kiln to introduce the flue gas in the roller hearth kiln and make the temperature of the flue gas in the first exhaust pipe higher than the temperature of the flue gas in the second exhaust pipe; A first power generation assembly, forming a first circuit for the flow of a first medium, the first circuit having a first heat exchanger and a second heat exchanger; each of the heat exchangers can, after absorbing the heat of the flue gas in each of the exhaust pipes, heat the first medium from a liquid state to a steam state and drive a first turbine to generate electricity; Wherein, along the direction of the first circuit, the first heat exchanger is close to the first turbine, the second heat exchanger is far from the first turbine, and the flue gas in the first exhaust pipe is used to heat the first heat exchanger, and the flue gas in the second exhaust pipe is used to heat the second heat exchanger.

2. The waste heat power generation system for sintering the positive electrode material according to claim 1, wherein It further includes a connecting pipe, the connecting pipe is connected between the first exhaust pipe and the second exhaust pipe, so that the flue gas with a higher temperature can, after heating the heat exchanger with a higher temperature, further heat the heat exchanger with a lower temperature.

3. The waste heat power generation system for sintering the positive electrode material according to claim 1, wherein It further includes a third heat exchanger and a third exhaust pipe; in the direction of the first circuit, the third heat exchanger is arranged between the first heat exchanger and the second heat exchanger, the third exhaust pipe is arranged between the first exhaust pipe and the second exhaust pipe, and the flue gas in the third exhaust pipe is used to heat the third heat exchanger; There are two connecting pipes, one connecting pipe is arranged between the first exhaust pipe and the third exhaust pipe, and the other connecting pipe is arranged between the third exhaust pipe and the second exhaust pipe.

4. The waste heat power generation system for sintering the positive electrode material according to claim 2, wherein It further includes a desuperheating pipeline assembly, and the desuperheating pipeline assembly is arranged outside the connecting pipe and / or outside the exhaust pipe.

5. The waste heat power generation system for sintering the cathode material according to any one of claims 1 to 4, characterized in that It further includes a second power generation assembly, the second power generation assembly forms a second circuit for the flow of a second medium, and the second power generation assembly can absorb the waste heat of the first medium passing through the first turbine in a steam state and / or the heat of the first medium in a liquid state, so as to change the second medium in the second power generation circuit from a liquid state to a steam state and drive a second turbine to generate electricity; the boiling point of the second medium is lower than the boiling point of the first medium.

6. The waste heat power generation system for sintering the positive electrode material according to claim 4, wherein, The second power generation assembly has a preheating pipe section, and the preheating pipe section can absorb the waste heat of the first medium passing through the first turbine in a steam state; and / or, The second power generation assembly has a heating pipe section, and the heating pipe section can absorb the heat of the first medium in a liquid state.

7. The waste heat power generation system for sintering the positive electrode material according to claim 6, wherein The first power generation assembly includes a hot water pipe section connected between the two heat exchangers, the hot water pipe section is connected with a hot water branch, and the hot water branch is provided with a regulating valve.

8. The waste heat power generation system for sintering the cathode material according to claim 1, wherein, The first turbine and the second turbine are coaxial to drive the same generator to generate electricity.

9. The waste heat power generation system for sintering the positive electrode material according to claim 1, characterized in that, It further includes a blower, the blower is arranged around the roller hearth kiln and close to the second exhaust pipe to introduce cold air to the second exhaust pipe in the roller hearth kiln to reduce the temperature of the flue gas in the second exhaust pipe.

10. The waste heat power generation system for sintering the positive electrode material according to claim 1, wherein, The end of the second smoke exhaust pipe is connected with a smoke extraction assembly, and the smoke extraction assembly includes a smoke extraction fan for extracting the flue gas in the second smoke exhaust pipe.

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