Waste heat double-path grading utilization system for directly calcining cement clinker through solar condensation

Abstract

The invention relates to the technical field of cement clinker calcination, and provides a solar condensation cement clinker direct calcination waste heat two-way grading utilization system which comprises a preheating module, a heat exchange module, a heat exchange module, a heat exchange module and a heat exchange module which are arranged in the material flow direction, the preheating module comprises a first preheating unit and a second preheating unit; the clinker reactor is arranged at the downstream of the preheating module and is used for calcining raw materials; a decomposed gas outlet of the clinker reactor is connected to the first preheating unit; the cooling machine is arranged at the downstream of the clinker reactor and is used for cooling the clinker; a waste gas outlet of the cooler is connected to the second preheating unit, and an air locking valve is arranged between the reactor and the cooler for tight isolation to prevent waste gas of the cooler from entering the reactor. Through the arrangement, heat in the decomposed gas and heat in the clinker cooling waste gas can be independently utilized, so that the purity of CO2 in the decomposed gas is guaranteed while waste heat is fully recycled and utilized, and the follow-up capture difficulty and capture cost of CO2 are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of cement clinker calcining, and in particular to a dual-path graded utilization system for waste heat from direct calcining of cement clinker using solar energy concentration. Background Art

[0002] During the production of cement produced directly by solar concentrating light, the CO2 waste gas generated by the thermal decomposition of limestone and the waste gas after cooling the clinker carry a large amount of waste heat. If the waste gas is directly discharged, it will lead to serious heat loss and increase energy consumption. In order to make full use of the waste heat, the traditional practice is to introduce the two waste gases into the preheater at the same time to preheat the raw material in direct contact, thereby effectively reducing the energy consumption in the raw material calcination stage.

[0003] Facts have proven that the above-mentioned solution can effectively achieve the efficient recovery and utilization of waste heat and achieve the purpose of energy conservation. However, the multi-stage preheater set up in this solution has a complex structure, a large size, and a high investment cost. In addition, the N2, O2 and raw material dust in the cooling air are mixed with the CO2 produced by the decomposition of the raw material, which greatly increases the difficulty and cost of subsequent CO2 capture.

[0004] Therefore, how to achieve efficient recovery and utilization of waste heat while taking into account carbon emissions has become an important issue that needs to be addressed urgently. Summary of the Invention

[0005] The present invention provides a dual-path graded utilization system for waste heat from direct calcination of cement clinker using solar concentrating technology, which is used to solve the defect in the prior art that it is difficult to balance waste heat recovery and utilization with carbon emissions. It can achieve waste heat recovery and utilization while reducing the difficulty and cost of capturing CO2.

[0006] The present invention provides a dual-path graded utilization system for waste heat from direct calcination of cement clinker using solar concentrating technology, comprising: A preheating module for preheating raw materials; the preheating module comprises a first preheating unit and a second preheating unit; A clinker reactor is provided downstream of the preheating module and is used for calcining raw materials; the decomposition gas outlet of the clinker reactor is connected to the first preheating unit; A cooler is arranged downstream of the clinker reactor and is used to cool the clinker; the exhaust gas outlet of the cooler is connected to the second preheating unit; an air lock valve is set between the cooler and the clinker reactor to strictly isolate them and prevent the exhaust gas of the cooler from entering the reactor.

[0007] According to a dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating method provided by the present invention, the first preheating unit comprises at least one sleeve-type indirect heat exchanger; The sleeve-type indirect heat exchanger comprises an outer shell and an inner shell, wherein a heat exchange interlayer cavity is formed between the outer shell and the inner shell; The upper side of the outer shell is provided with a heat exchange inlet connected to the heat exchange interlayer cavity, and the lower side is provided with a heat exchange outlet connected to the heat exchange interlayer cavity, and the heat exchange inlet is connected to the decomposition gas outlet; The top end of the inner cylinder is provided with a raw material inlet, and the bottom end is provided with a raw material outlet.

[0008] According to a dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating method provided by the present invention, the heat exchange interlayer cavity is hollow, and the heat exchange inlet is arranged tangentially along the heat exchange interlayer cavity.

[0009] According to a dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating method provided by the present invention, the second preheating unit comprises at least one downstream direct heat exchanger; The downstream direct heat exchanger comprises: The heat exchange tube has a tube cavity inlet at one end and a tube cavity outlet at the other end, and a material inlet is provided between the tube cavity inlet and the tube cavity outlet and near the tube cavity inlet; The tube cavity inlet is connected to the exhaust gas outlet, and the tube cavity outlet is connected to a first gas-solid separation module.

[0010] According to a dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating method provided by the present invention, the heat exchange tubes are configured as a straight segment structure or a circuitous curved inverted "U" structure.

[0011] According to the dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating method provided by the present invention, the second preheating unit is arranged downstream of the first preheating unit; The raw material outlet is connected to the material inlet; the tube cavity outlet is connected to the clinker reactor through the first gas-solid separation module.

[0012] According to a dual-path graded utilization system for waste heat from direct calcination of cement clinker using solar energy concentration provided by the present invention, a second gas-solid separation module is provided between the cooler and the second preheating unit.

[0013] A dual-path graded utilization system for waste heat from direct calcination of cement clinker using solar concentrating technology provided by the present invention also includes a solar heater for providing heat to the clinker reactor.

[0014] According to the present invention, a dual-path graded utilization system for waste heat from direct calcination of cement clinker using solar concentrating technology is provided, wherein the solar heater comprises a heliostat and a concentrating mirror; The heliostat is used to reflect sunlight to the concentrator, and the concentrator is used to concentrate sunlight to heat the clinker reactor.

[0015] According to the present invention, a dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating technology further comprises a CO2 capture module, wherein the CO2 capture module is connected to the first preheating unit via a first fan; and / or, It also includes an exhaust gas emission module located downstream of the first gas-solid separation module, the exhaust gas emission module is connected to the first gas-solid separation module via a second fan; and / or, It also includes a raw material silo, which is connected to the raw material inlet of the first preheating unit through a weighing scale; and / or, It also includes an electric heater integrated in the clinker reactor (20) for providing heat to the clinker reactor (20).

[0016] According to a dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating method provided by the present invention, the first gas-solid separation module comprises a first cyclone and a dust collector connected in sequence; The gas inlet of the first cyclone is connected to the tube cavity outlet, and the gas outlet is connected to the gas inlet of the dust collector; The solids outlet of the first cyclone and the dust collector are connected to the clinker reactor.

[0017] According to a dual-path graded utilization system for waste heat from direct calcination of cement clinker using solar energy concentration provided by the present invention, the second gas-solid separation module includes a second cyclone.

[0018] According to the dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating method provided by the present invention, an air lock valve is provided between the clinker reactor and the cooler.

[0019] The present invention provides a dual-path graded utilization system for waste heat from direct calcination of cement clinker using solar energy concentration. The raw material is preheated by a preheating module during transportation and then enters the clinker reactor. The raw material is calcined and decomposed in the clinker reactor to generate clinker and decomposition gas containing high-purity CO2. The high-temperature decomposition gas enters the first preheating unit through the decomposition gas outlet to provide heat for the first preheating unit, while the clinker enters the downstream cooler and is cooled by blowing air into the cooler. The cooled high-temperature exhaust gas enters the second preheating unit through the exhaust gas outlet to provide heat for the second preheating unit. In this way, the heat in the decomposition gas and the clinker cooling exhaust gas is separately utilized, thereby fully recovering and utilizing the waste heat while ensuring the purity of CO2 in the decomposition gas, thereby reducing the difficulty and cost of subsequent CO2 capture. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 This is one of the structural diagrams of the dual-path graded utilization system for waste heat from direct calcination of cement clinker using solar energy provided by an embodiment of the present invention.

[0022] Figure 2 This is the second structural diagram of the dual-path graded utilization system for waste heat from direct calcination of cement clinker using solar energy provided by an embodiment of the present invention.

[0023] Reference numerals: 10. Preheating module; 11. First preheating unit; 110. Outer shell; 111. Inner cylinder; 112. Heat exchange interlayer cavity; 113. Heat exchange inlet; 114. Heat exchange outlet; 115. Raw material inlet; 116. Raw material outlet; 12. Second preheating unit; 120. Heat exchange tube; 121. Tube cavity inlet; 122. Tube cavity outlet; 123. Material inlet; 20. Clinker reactor; 21. Air lock valve; 30. Cooler; 31. Blower; 40. CO2 capture module; 41. First fan; 50. First gas-solid separation module; 51. First cyclone; 52. Dust collector; 60. Raw material silo; 61. Weighing scale; 70. Exhaust gas emission module; 71. Second fan; 80. Second gas-solid separation module; 90. Solar heater; 91. Heliostat; 92. Concentrator. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0025] In order to better understand the dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating technology provided in an embodiment of the present invention, its application background is first introduced. During the cement production process, in order to reduce heat loss and energy consumption, the waste gas generated by the thermal decomposition of limestone and the waste gas after cooling the clinker are generally introduced into the preheater to preheat the raw material, so as to reduce energy consumption in the raw material calcination stage.

[0026] The above scheme can effectively realize the efficient recovery and utilization of waste heat and achieve the purpose of energy saving. However, the multi-stage preheater set up in this scheme has a complex structure, a large size, and a high investment cost. In addition, the N2, O2 and raw material dust in the cooling air are mixed with the CO2 produced by the decomposition of the raw material, which greatly increases the difficulty and cost of subsequent CO2 capture.

[0027] In light of this, embodiments of the present invention provide a dual-path, graded waste heat utilization system for direct solar-powered cement clinker calcination. This system can simultaneously recover and utilize waste heat while maintaining the purity of the CO2 produced by carbonate decomposition, reducing the difficulty and cost of subsequent CO2 capture. This dual-path waste heat exchange method replaces the bulky preheater system of traditional cement production, reducing system resistance and significantly lowering investment and operating costs for cement companies. This provides technical support for the cement industry's future energy conservation and emission reduction efforts in cement clinker production using solar energy.

[0028] The following combination Figures 1 to 2 The invention describes a dual-path graded utilization system for waste heat from direct calcination of cement clinker using solar energy concentration.

[0029] Reference Figures 1 to 2 A dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating direct calcination includes a preheating module 10, a clinker reactor 20 and a cooler 30 arranged along the material flow direction; wherein the preheating module 10 is used to preheat raw materials, and includes a first preheating unit 11 and a second preheating unit 12; the clinker reactor 20 is arranged downstream of the preheating module 10, and is suitable for calcining raw materials, and the decomposition gas outlet of the clinker reactor 20 is connected to the first preheating unit 11; the cooler 30 is arranged downstream of the clinker reactor 20, and is used to cool the clinker, and the exhaust gas outlet of the cooler 30 is connected to the second preheating unit 12.

[0030] Through the above technical solution, the raw material is preheated by the preheating module 10 during the transportation process and then enters the clinker reactor 20. The raw material is calcined and decomposed in the clinker reactor 20 to produce clinker and decomposition gas with high-purity CO2. The high-temperature decomposition gas enters the first preheating unit 11 through the decomposition gas outlet to provide heat for the first preheating unit 11, and the clinker enters the downstream cooler 30. The clinker is cooled by blowing air into the cooler 30. The cooled high-temperature exhaust gas enters the second preheating unit 12 through the exhaust gas outlet to provide heat for the second preheating unit 12. In this way, the heat in the decomposition gas and the clinker cooling exhaust gas is separately utilized, thereby fully recovering and utilizing the waste heat while ensuring the purity of CO2 in the decomposition gas, reducing the subsequent difficulty and cost of CO2 capture.

[0031] In some feasible examples of the present invention, the first preheating unit 11 and the second preheating unit 12 in the preheating module 10 can be selected from a direct contact heat exchanger or an indirect heat exchanger according to actual needs.

[0032] In comparison, direct contact heat exchangers have high heat transfer efficiency due to the lack of heat loss in the intermediate medium (such as the heat exchange wall). In theory, they are a better choice for the first preheating unit 11 and the second preheating unit 12. However, in actual applications, it is found that if the first preheating unit 11 adopts a direct contact heat exchanger, the decomposition gas containing high-purity CO2 will directly contact the raw material powder, and the decomposition gas after heat exchange will contain a large amount of dust, which will also have an adverse effect on the subsequent CO2 capture, increasing the difficulty and cost of CO2 capture.

[0033] Taking into account both cost and economic benefits, in a preferred embodiment of the present invention, the first preheating unit 11 includes at least one sleeve-type indirect heat exchanger. This configuration effectively prevents direct contact between the decomposition gas and the raw meal powder, reduces the introduction of impurities, ensures the purity of the CO2 in the decomposition gas, and thus reduces the difficulty and cost of subsequent CO2 capture.

[0034] In a specific example of the present invention, the sleeve-type indirect heat exchanger includes an outer shell 110 and an inner cylinder 111; a heat exchange interlayer cavity 112 is formed between the outer shell 110 and the inner cylinder 111; a heat exchange inlet 113 connected to the heat exchange interlayer cavity 112 is provided on the upper side of the outer shell 110, and a heat exchange outlet 114 connected to the heat exchange interlayer cavity 112 is provided on the lower side, and the heat exchange inlet 113 is connected to the decomposition gas outlet of the clinker reactor 20; a raw material inlet 115 is provided at the top end of the inner cylinder 111, and a raw material outlet 116 is provided at the bottom end.

[0035] Specifically, a heat exchange interlayer cavity 112 is formed between the outer shell 110 and the inner cylinder 111, and the interior of the inner cylinder 111 is formed as a channel for raw materials to pass through. In actual application, the high-temperature decomposition gas enters the heat exchange interlayer cavity 112 from the heat exchange inlet 113 on the upper side and is discharged from the heat exchange outlet 114 at the bottom. The raw material enters the sleeve-type indirect heat exchanger from the raw material inlet 115 at the top of the inner cylinder 111 and is discharged from the raw material outlet 116 at the bottom under the action of its own gravity. During the process of the raw material flowing through the inner cylinder 111, the decomposition gas in the heat exchange interlayer cavity 112 can preheat the raw material.

[0036] The decomposition gas enters and exits the heat exchange interlayer chamber 112 from above, with the heat exchange inlet 113 arranged tangentially to the interlayer chamber 112. This arrangement allows the decomposition gas to enter the interlayer chamber 112 tangentially, causing it to spiral downward within the chamber 112. This prolongs the decomposition gas's path and its residence time within the interlayer chamber 112, allowing it to more fully preheat the raw meal and improving heat exchange efficiency. The vertical arrangement of the raw meal inlet 115 and outlet 116 allows the raw meal to pass through the first preheating unit 11 under its own gravity, eliminating the need for a complex conveying structure, simplifying the structure, and reducing costs.

[0037] After the decomposition gas undergoes heat exchange, the CO2 in it needs to be captured. In a further example of the present invention, the solar concentration direct calcination of cement clinker waste heat dual-path graded utilization system also includes a CO2 capture module 40, and the CO2 capture module 40 is connected to the heat exchange outlet 114 of the first preheating unit 11 through the first fan 41.

[0038] Specifically, the first fan 41 can provide driving force for the entire process of decomposition gas from heat exchange to CO2 capture.

[0039] In some optional examples of the present invention, according to different working principles, the CO2 capture module 40 can adopt different technical forms, such as the coupling of one or more technologies such as membrane separation, cryogenic separation, chemical absorption, etc., which is not specifically limited in the embodiments of the present invention.

[0040] In one embodiment of the present invention, the second preheating unit 12 includes at least one downstream direct heat exchanger. This configuration allows the cooling exhaust gas discharged from the cooler 30 to directly exchange heat with the raw material powder through the downstream direct heat exchanger, thereby improving heat exchange efficiency.

[0041] In a specific example of the present invention, the second preheating unit 12 includes a heat exchange tube 120, one end of the heat exchange tube 120 is provided with a tube cavity inlet 121, and the other end is provided with a tube cavity outlet 122, and a material inlet 123 is provided between the tube cavity inlet 121 and the tube cavity outlet 122 and near the tube cavity inlet 121; wherein, the tube cavity inlet 121 is connected to the exhaust gas outlet, and the tube cavity outlet 122 is connected to the first gas-solid separation module 50.

[0042] Specifically, the tube cavity of the heat exchange tube 120 can not only provide a contact space for the raw material and the cooling exhaust gas, but also constitute a conveying channel for the raw material. In actual application, after the cooling exhaust gas is discharged from the exhaust gas outlet of the cooler 30, it enters the heat exchange tube 120 through the tube cavity inlet 121. At the same time, the raw material powder enters the heat exchange tube 120 from the material inlet 123. The high-temperature cooling exhaust gas and the raw material powder are in direct contact and heat exchange in the heat exchange tube 120, and carried by the cooling exhaust gas, the raw material powder is transported along the heat exchange tube 120 to the first gas-solid separation module 50 for gas-solid separation. The separated cooling exhaust gas is subsequently processed, and the raw material powder is used as the raw material for calcination.

[0043] With this arrangement, the heat exchange method of direct contact between raw material powder and cooling exhaust gas can effectively improve the heat exchange efficiency and realize the full recovery and utilization of waste heat. In addition, the use of downstream heat exchange method can enable the cooling exhaust gas to carry the raw material powder together for transportation, eliminating the complex conveying structure, achieving structural simplification and reducing costs.

[0044] It should be noted here that pneumatic conveying of powdered materials by wind pressure is a very mature technology, and the main improvement of the downstream direct heat exchanger in the embodiment of the present invention lies in the combination of pneumatic conveying and direct contact heat exchange. Those skilled in the art are fully capable of combining their own professional knowledge and the size of the wind speed designed under actual working conditions to realize the conveying of raw material powder by cooling exhaust gas and the control of its residence time in the heat exchanger. The specific parameters need to be set in combination with the actual working conditions, and no specific restrictions are made in the embodiment of the present invention.

[0045] The heating time of the raw material in the downstream direct heat exchanger can be prolonged by extending the length of the heat exchange tube 120, but this will result in an excessively high overall height of the downstream direct heat exchanger. Therefore, in a further example of the present invention, referring to Figure 2 The heat exchange tube 120 is configured as a curved structure with winding bends, thereby extending the heat exchange path while reducing the overall height of the downstream direct heat exchanger.

[0046] In a more specific example of the present invention, the heat exchange tube 120 includes at least two parallel straight segments, and the tail end of the upstream straight segment is connected to the head end of the downstream straight segment by a curved segment, so that the heat exchange tube 120 is formed into a tortuous curved structure. For example, when the heat exchange tube 120 has two straight segments, the whole is formed into an inverted "U"-shaped structure.

[0047] Taking into account factors such as material flow resistance, the heat exchange tube 120 should not be set too long, and the number of curved sections should not be too large. In this embodiment, the heat exchange tube 120 is provided with two straight sections and a curved section for connecting the two straight sections, so that the heat exchange tube 120 as a whole has an inverted "U"-shaped structure. The length of a single straight section and a curved section can be designed based on actual working conditions.

[0048] In one example of the present invention, the second preheating unit 12 is arranged downstream of the first preheating unit 11, the raw material outlet 116 of the first preheating unit 11 is connected to the material inlet 123 of the second preheating unit 12, and the pipe body outlet of the second preheating unit 12 is connected to the clinker reactor 20 through the above-mentioned first gas-solid separation module 50.

[0049] In a further example of the present invention, the solar concentrated direct calcination cement clinker waste heat dual-path graded utilization system further includes a raw material silo 60 , which is connected to the raw material inlet 115 of the first preheating unit 11 through a weighing scale 61 .

[0050] With such arrangement, the raw material powder in the raw material bin 60 is measured by the weighing scale 61 and then enters the raw material inlet 115 of the first preheating unit 11, and is then discharged from the raw material outlet 116 under the action of its own gravity. The raw material powder is preliminarily preheated by the decomposition gas during the process of flowing through the first preheating unit 11. The raw material powder after the preliminarily preheating enters the second preheating unit 12 from the material inlet 123 and undergoes direct contact heat exchange with the cooling exhaust gas discharged from the cooler 30. At the same time, it is transported to the first gas-solid separation module 50 for gas-solid separation under the entrainment of the cooling exhaust gas. The separated raw material enters the clinker reactor 20 for calcination, and the cooling exhaust gas is subjected to subsequent treatment.

[0051] In a further example of the present invention, the first gas-solid separation module 50 includes a first cyclone 51 , the air inlet of the first cyclone 51 is connected to the tube cavity outlet 122 of the second preheating unit 12 , and the solid outlet is connected to the clinker reactor 20 .

[0052] In a further example of the present invention, the first gas-solid separation module 50 also includes a dust collector 52; wherein, the air outlet of the first cyclone 51 is connected to the air inlet of the dust collector 52, and the solid outlet of the dust collector 52 can be connected to the clinker reactor 20 according to actual needs.

[0053] Specifically, the first cyclone 51 is mainly used to separate the raw material powder in the exhaust gas, and the dust collector 52 is used to purify the gas after passing through the first cyclone 51 again so that it meets the discharge standard. The dust collector 52 can adopt an existing bag dust collector, an electrostatic precipitator, etc., and there is no specific limitation in the embodiment of the present invention.

[0054] With such an arrangement, the raw material powder first enters the first cyclone 51 under the entrainment of the cooling exhaust gas. After separation by the first cyclone 51, the solid powder enters the clinker reactor 20 for calcination, and the gas enters the dust collector 52 for further purification, so that the exhaust gas meets the discharge standard, and the solid powder separated by the dust collector 52 can enter the clinker reactor 20 for recycling.

[0055] In a further example of the present invention, the dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating means also includes a waste gas emission module 70, which is arranged downstream of the first gas-solid separation module 50 and is connected to the gas emission port of the dust collector 52 through a second fan 71 for discharging waste gas.

[0056] More specifically, the exhaust gas discharge module 70 may be a chimney.

[0057] In the traditional cement calcining process, in order to improve the quality of the calcined cement clinker, a blower 31 integrated in the cooler 30 is required to blow cold air into the cooler 30 to rapidly cool the clinker at about 1350°C, which will inevitably result in a large amount of clinker powder being mixed in the cooling exhaust gas.

[0058] To reduce cement clinker loss, in one embodiment of the present invention, a second gas-solid separation module 80 is provided between the cooler 30 and the second preheating unit 12 to separate the clinker from the cooling exhaust gas. Specifically, the second gas-solid separation module 80 includes a second cyclone, the gas inlet of which is connected to the exhaust gas outlet of the cooler 30, and the gas outlet of which is connected to the lumen inlet 121 of the second preheating unit 12.

[0059] It should be further explained here that an air lock valve 21 is provided between the clinker reactor 20 and the cooler 30. The air lock valve 21 can isolate the air pressure between the clinker reactor 20 and the cooler 30 to prevent air leakage, ensure that the decomposition gas and the cooling exhaust gas are separately drawn out without interfering with each other, and simultaneously realize the discharge of clinker from the clinker reactor 20 to the cooler 30. The specific structure and working principle of the air lock valve 21 can be referred to the existing technology and will not be described in detail in the embodiments of the present invention.

[0060] Through the above technical solution, the heat in the decomposition gas and clinker cooling waste gas can be utilized separately, thereby achieving full recovery and utilization of waste heat while ensuring the purity of CO2 in the decomposition gas, saving a lot of costs for subsequent capture and purification of CO2.

[0061] In order to further reduce CO2 emissions, in one example of the present invention, the solar concentrated direct calcination cement clinker waste heat dual-path graded utilization system further includes a solar heater 90 for providing heat to the clinker reactor 20.

[0062] In a further example of the present invention, the solar heater 90 generally includes a heliostat 91 and a concentrator 92; wherein the heliostat 91 tracks the position of the sun through a plane mirror and a mechanical tracking system and reflects sunlight onto the concentrator 92, and the concentrator 92 is used to concentrate sunlight to heat the clinker reactor 20.

[0063] It should be noted that the above description of the solar heater 90 is only a brief description. Parameters such as the number and arrangement of the heliostats 91 and the concentrators 92 need to be designed based on the actual application scenario. In addition, a light-transmitting cover can be provided on the clinker reactor 20 to concentrate the sunlight collected by the concentrators 92 into the high-temperature area to meet the temperature requirements for raw material calcination.

[0064] Through the above technical solution, during the cement calcination process, only high-purity and high-temperature CO2 waste gas is produced by the thermal decomposition of limestone in the raw material. Therefore, it is only necessary to capture this part of the high-purity CO2 waste gas to greatly reduce carbon emissions.

[0065] In a further example of the invention, a combination of multiple non-fuel heat sources can be used to provide heat for the clinker reactor 20, such as a combination of electricity and solar energy, thereby reducing the limitations of a single heat source, which will not be described in detail in the embodiments of the present invention.

[0066] Finally, it should be pointed out that the various devices or components not described in detail above, such as the clinker reactor 20, the cooler 30, the heliostat 91, the concentrator 92, etc., are all commercially available devices or components. Their specific structures can refer to the existing technology and are not described in detail in the embodiments of the present invention.

[0067] It is understood that those skilled in the art may combine and integrate different embodiments or examples and features of different embodiments or examples described in this specification without mutual contradiction.

[0068] By the dual-path graded utilization system for waste heat of directly calcined cement clinker by solar concentrating method provided by the embodiment of the present invention, the raw material is preheated by the preheating module 10 during transportation and then enters the clinker reactor 20. The raw material is calcined and decomposed in the clinker reactor 20 to generate clinker and decomposition gas with high-purity CO2. The high-temperature decomposition gas enters the first preheating unit 11 through the decomposition gas outlet to provide heat for the first preheating unit 11, and the clinker enters the downstream cooler 30. The clinker is cooled by blowing air into the cooler 30. The cooled high-temperature exhaust gas enters the second preheating unit 12 through the exhaust gas outlet to provide heat for the second preheating unit 12. In this way, the heat in the decomposition gas and the clinker cooling exhaust gas is separately utilized, thereby fully recovering and utilizing the waste heat while ensuring the purity of CO2 in the decomposition gas, thereby reducing the difficulty and cost of subsequent CO2 capture.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A dual-path graded utilization system for waste heat from direct calcination of cement clinker using solar concentrating technology, characterized in that: Including those arranged along the material flow direction: A preheating module (10) for preheating raw materials; the preheating module (10) comprises a first preheating unit (11) and a second preheating unit (12); A clinker reactor (20) is provided downstream of the preheating module (10) and is used for calcining raw materials; a decomposition gas outlet of the clinker reactor (20) is connected to the first preheating unit (11); A cooler (30) is provided downstream of the clinker reactor (20) for cooling the clinker; an exhaust gas outlet of the cooler (30) is connected to the second preheating unit (12); and an air lock valve (21) is provided between the cooler (30) and the clinker reactor (20) for strict isolation, preventing the exhaust gas of the cooler (30) from entering the reactor.

2. The dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating technology according to claim 1 is characterized in that: The first preheating unit (11) comprises at least one sleeve-type indirect heat exchanger; The sleeve-type indirect heat exchanger comprises an outer shell (110) and an inner shell (111), wherein a heat exchange interlayer cavity (112) is formed between the outer shell (110) and the inner shell (111); The outer shell (110) is provided with a heat exchange inlet (113) connected to the heat exchange interlayer cavity (112) on its upper side, and a heat exchange outlet (114) connected to the heat exchange interlayer cavity (112) on its lower side, and the heat exchange inlet (113) is connected to the decomposition gas outlet; The top end of the inner cylinder (111) is provided with a raw material inlet (115), and the bottom end is provided with a raw material outlet (116).

3. The dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating technology according to claim 2 is characterized in that: The heat exchange interlayer cavity (112) is hollow, and the heat exchange inlet (113) is arranged along the tangent direction of the heat exchange interlayer cavity (112).

4. The dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating technology according to claim 2 is characterized in that: The second preheating unit (12) comprises at least one downstream direct heat exchanger; The downstream direct heat exchanger comprises: The heat exchange tube (120) is provided with a tube cavity inlet (121) at one end and a tube cavity outlet (122) at the other end, and a material inlet (123) is provided between the tube cavity inlet (121) and the tube cavity outlet (122) and near the tube cavity inlet (121); The tube cavity inlet (121) is connected to the exhaust gas outlet, and the tube cavity outlet (122) is connected to a first gas-solid separation module (50).

5. The dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating technology according to claim 4 is characterized in that: The heat exchange tube (120) is configured as a straight segment structure or a circuitous curved inverted "U"-shaped structure.

6. The dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating technology according to claim 4 is characterized in that: The second preheating unit (12) is arranged downstream of the first preheating unit (11); The raw material outlet (116) is connected to the material inlet (123); the tube cavity outlet (122) is connected to the clinker reactor (20) through the first gas-solid separation module (50).

7. The dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating technology according to claim 1 is characterized in that: A second gas-solid separation module (80) is provided between the cooler (30) and the second preheating unit (12).

8. The dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating technology according to any one of claims 1 to 7, characterized in that: Also included is a solar heater (90) for providing heat to the clinker reactor (20).

9. The dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating technology according to claim 8 is characterized in that: The solar heater (90) includes a heliostat (91) and a concentrator (92); The heliostat (91) is used to reflect sunlight to the concentrator (92), and the concentrator (92) is used to concentrate sunlight to heat the clinker reactor (20).

10. The dual-path graded utilization system for waste heat from direct calcination of cement clinker by solar concentrating technology according to claim 4 is characterized in that: It also includes a CO2 capture module (40), wherein the CO2 capture module (40) is connected to the first preheating unit (11) via a first fan (41); and / or, It also includes an exhaust gas discharge module (70) located downstream of the first gas-solid separation module (50), wherein the exhaust gas discharge module (70) is connected to the first gas-solid separation module (50) via a second fan (71); and / or, It also includes a raw material bin (60), wherein the raw material bin (60) is connected to the raw material inlet (115) of the first preheating unit (11) via a weighing scale (61); and / or, It also includes an electric heater integrated in the clinker reactor (20) for providing heat to the clinker reactor (20).

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