Kiln waste heat power generation system with high utilization rate

Abstract

The invention provides a kiln waste heat power generation system with a high utilization rate. The kiln waste heat power generation system comprises a waste heat boiler, a steam drum, a steam turbine and a generator. The waste heat boiler comprises a boiler body, a smoke inlet pipe is connected to the lower portion of the boiler body and connected with the tail end of the kiln, a fixed barrel with an opening in the upper end is arranged in the boiler body, and the edge of the lower end of the fixed barrel extends outwards and is fixedly connected with the inner wall of the boiler body. A rotatable movable barrel with an opening in the lower end is arranged in the furnace body, and the movable barrel is coaxially arranged outside the fixed barrel in a sleeving manner; the fixed cylinder body and the movable cylinder body which are coaxially arranged are designed in the furnace body, a multi-layer annular space is formed between the fixed cylinder body and the movable cylinder body, the continuous snake-shaped heat exchange pipes are arranged in the spaces, and after entering the furnace body through the smoke inlet pipe, smoke sequentially flows up and down in a reciprocating mode along the annular gap between the fixed cylinder body and the movable cylinder body; and the retention time of the flue gas in the furnace body is obviously prolonged, so that more sufficient heat exchange with the working medium in the heat exchange tube is realized.

Description

Technical Field

[0001] This invention belongs to the field of waste heat power generation technology, specifically relating to a kiln waste heat power generation system with high utilization rate. Background Technology

[0002] In cement production, clinker calcination typically takes place in a rotary kiln. During operation, the kiln requires a continuous supply of large amounts of fuel to maintain the high-temperature environment, and the exhaust gas contains abundant heat energy. To improve energy efficiency and reduce fuel consumption, some cement companies install waste heat boilers along the kiln tail flue gas path. These waste heat power generation systems convert the heat energy in the high-temperature flue gas into steam to drive a steam turbine for power generation, thus achieving waste heat recovery and utilization. Such waste heat power generation systems can recover heat from the kiln exhaust gas to a certain extent and are an important means of energy conservation and emission reduction in the cement industry.

[0003] However, existing waste heat recovery systems for kilns still have the following shortcomings: First, existing systems generally adopt a vertically arranged heat exchange tube structure, with flue gas passing horizontally through the heat exchange tube bundle. This results in a short contact time between the flue gas and the working fluid inside the tubes, leading to low heat exchange efficiency. Simultaneously, the flow path of the flue gas inside the waste heat boiler is short, and the residence time is limited, preventing sufficient heat exchange with the tube walls. Consequently, a large amount of heat in the high-temperature flue gas is not fully utilized. Second, current waste heat recovery mainly focuses on the flue gas area at the tail end of the kiln, while the kiln head area also contains high-temperature waste heat flow, which is not effectively recovered and reused. This results in the front-end heat being wasted and discharged to the outside, leading to low overall thermal energy utilization. Third, the flue gas discharged from the kiln often carries a large amount of high-temperature dust particles and incompletely burned fine matter. These particles easily adhere to or deposit on the tube wall surface when flowing through the heat exchange tubes, forming ash or scale layers, increasing heat transfer resistance, and seriously affecting heat exchange efficiency and the long-term stable operation of the system. In addition, the temperature of the flue gas at the kiln tail flue gas flues greatly and is significantly affected by factors such as fuel composition and kiln operating conditions. When the flue gas temperature is too high, some heat cannot be absorbed in time, resulting in heat energy waste; while when the flue gas temperature is too low, the heat exchange efficiency and steam production capacity decrease, making it difficult to meet the demand for stable power generation. Summary of the Invention

[0004] This invention provides a high-efficiency kiln waste heat power generation system to solve the problems of low flue gas heat exchange efficiency, insufficient heat utilization, ineffective recovery of kiln head heat, dust particle adhesion affecting heat exchange, and unstable energy utilization caused by flue gas temperature fluctuations in the existing cement kiln waste heat utilization process.

[0005] The technical solution adopted in this invention is: a high-utilization kiln waste heat power generation system, including a waste heat boiler, a steam drum, a steam turbine, and a generator;

[0006] The waste heat boiler includes a furnace body, with a flue gas inlet pipe connected to the bottom of the furnace body and connected to the tail end of the kiln. Inside the furnace body is a fixed cylinder with an open top, and the lower edge of the fixed cylinder extends outward and is fixedly connected to the inner wall of the furnace body. Inside the furnace body is a rotatable movable cylinder with an open bottom. The movable cylinder is coaxially sleeved on the outside of the fixed cylinder, and there are gaps between the inner wall of the movable cylinder and the outer wall of the fixed cylinder, and between the outer wall of the movable cylinder and the inner wall of the furnace body. A central rod extends downward from the center of the movable cylinder.

[0007] A continuous heat exchange tube with a serpentine structure is provided in the area between the inner wall of the furnace body and the outer wall of the movable cylinder, between the inner wall of the movable cylinder and the outer wall of the fixed cylinder, and between the inner wall of the fixed cylinder and the central rod. There are several heat exchange tubes, which are evenly distributed around the center of the furnace body.

[0008] The lower end of the fixed cylinder extends downward and is connected to the flue gas inlet pipe. The flow path of the working fluid inside the heat exchange tube is configured to be generally opposite to the flow path of the flue gas.

[0009] One end of the heat exchange tube is connected to a circular liquid inlet pipe, and the other end is connected to a circular liquid outlet pipe. The liquid inlet pipe is located in the area between the outer wall of the movable cylinder and the inner wall of the furnace, and is positioned away from the flue gas inlet pipe. The liquid outlet pipe is located inside the fixed cylinder and close to the flue gas inlet pipe.

[0010] The main inlet pipe is connected to an inlet pipe, and the end of the inlet pipe is connected to a steam drum, which is configured to introduce the working fluid in the steam drum into the inlet pipe; the main outlet pipe is connected to an outlet pipe, and the end of the outlet pipe is installed on the steam-water separator on the steam drum, which is configured to introduce the high-temperature working fluid into the steam-water separator.

[0011] Cleaning brushes are installed on the inner wall, outer wall, and outer wall of the central rod of the movable cylinder. The cleaning brushes extend along the central axis of the furnace body and are set to extend towards the heat exchange tube.

[0012] The furnace body is fixed with a support rod inside. The middle position of the support rod is connected to the movable cylinder through a bearing. The upper outer wall of the movable cylinder is equipped with fan blades.

[0013] The central axis of the flue gas inlet pipe is tangent to the circumference of the fixed cylinder. A conical ash collection area is formed at the lower end of the fixed cylinder and below the flue gas inlet pipe. An ash collection pipe is connected to the bottom of the area between the fixed cylinder and the inner wall of the furnace, and the ash collection pipe extends to the outside of the furnace. Valves are installed below the ash collection area and below the ash collection pipe.

[0014] The heat exchange tube includes an inner layer, a middle layer and an outer layer arranged sequentially from the inside out, with the middle layer being a phase change material layer.

[0015] The top of the furnace body is connected to a flue pipe, inside which a superheater, a reheater, and an economizer are installed in sequence. The inlet of the superheater is connected to an exhaust pipe, which is connected to a steam-water separator installed on the steam drum. The outlet of the superheater is connected to a steam main pipe, the end of which is connected to a steam turbine, and the end of which is connected to a generator. The inlet of the reheater is connected to the steam turbine, and the outlet is connected to the steam main pipe. The inlet of the economizer is connected to the end of the steam turbine, and the outlet is connected to the kiln gas system.

[0016] The exhaust pipe is equipped with an exhaust fan, and a dust removal device and a cooling tower are connected to the end of the exhaust pipe; it also includes a heat pipe, the hot end of which is located at the front end of the kiln, and the cold end of which is connected to a steam generator, the end of which is connected to a steam-water separator.

[0017] The system also includes a gear installed above the center of the movable cylinder, and a horizontally movable tooth block inside the furnace body. When the tooth block moves toward the center of the furnace body, it can mesh with the gear. When the tooth block moves away from the center of the furnace body, the gear separates from the tooth block.

[0018] The beneficial effects of this invention are as follows:

[0019] (1) The present invention designs a fixed cylinder and a movable cylinder arranged coaxially inside the furnace body, forming a multi-layer annular space between them, and arranges heat exchange tubes in a continuous serpentine shape in these spaces. After the flue gas enters the furnace body through the flue gas inlet pipe, it flows up and down repeatedly along the annular gap between the fixed cylinder and the movable cylinder, which significantly increases the residence time of the flue gas inside the furnace body, thereby achieving more complete heat exchange with the working fluid in the heat exchange tube.

[0020] Meanwhile, the present invention designs the flow direction of the working fluid in the heat exchange tube to be opposite to the overall flow direction of the flue gas, forming a counter-current heat exchange structure. This heat exchange method can maintain a high average temperature difference during the heat transfer process, overcome the problem of the temperature difference gradually decreasing in parallel flow heat exchange, and significantly improve the heat exchange driving force and heat transfer efficiency.

[0021] In addition, the working fluid inside the heat exchange tube flows from the outside to the inside and finally flows out near the center of the furnace body. This is exactly the area where the high-temperature flue gas has just entered the furnace body, which allows the working fluid to absorb the heat of the high-temperature zone of the flue gas before flowing out, thereby achieving secondary enhanced heating at the outlet end and resulting in a higher overall heat exchange utilization rate.

[0022] (2) The present invention has cleaning brushes distributed in the vertical direction installed on the inner wall, outer wall and outer wall of the central rod of the movable cylinder, and a rotation drive structure is set on the movable cylinder. After a period of use, the movable cylinder can be rotated, and the cleaning brushes can clean the outer wall of the adjacent heat exchange tubes, remove the dust particles attached to the flue gas in time, prevent the tube wall from scaling or ash accumulation, avoid the heat exchange efficiency decrease due to the increase of thermal resistance, and thus maintain the long-term stable and efficient operation of the system.

[0023] (3) This invention not only utilizes waste heat boiler to recover high-temperature flue gas at the kiln tail for power generation, but also transfers the high-temperature radiant heat and flue gas heat in the kiln head area to the steam generator at the cold end by setting heat pipes at the front end of the kiln. The steam generated by the steam generator is further introduced into the steam-water separator and merged with the steam in the waste heat boiler system into the steam main pipe to participate in power generation, thereby realizing the coordinated recovery and centralized utilization of waste heat at the kiln head and kiln tail, which greatly improves the overall thermal energy utilization rate and power generation output capacity of the kiln.

[0024] (4) The heat exchange tube of the present invention comprises an inner layer, a middle layer and an outer layer. The middle layer is a phase change material layer. The phase change material absorbs latent heat and melts to store energy under the action of high-temperature flue gas. When the flue gas temperature decreases or the working fluid temperature is too low, the phase change material releases the stored heat to compensate and achieves the time-domain balance of heat. This not only alleviates the problem of unstable heat input caused by the temperature fluctuation of the kiln tail flue gas, but also provides auxiliary heating in the low load stage, improving the continuity of system operation and the stability of the power generation process. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0026] Figure 2 This is a structural diagram of the waste heat boiler of the present invention;

[0027] Figure 3 This is a cross-sectional view of the waste heat boiler of the present invention;

[0028] Figure 4 This is a structural diagram of the heat exchange tube of the present invention.

[0029] in:

[0030] 1. Heat pipe; 2. Steam generator; 3. Steam-water separator; 4. Steam drum; 5. Liquid inlet pipe; 6. Liquid inlet main pipe; 7. Movable cylinder; 8. Liquid outlet pipe; 9. Central rod; 10. Liquid outlet main pipe; 11. Flue gas inlet pipe; 12. Ash collection area; 13. Ash collection pipe; 14. Cleaning brush; 15. Fixed cylinder; 16. Heat exchanger tube; 1601. Inner layer; 1602. Middle layer; 1603. Outer layer; 17. Furnace body; 18. Fan blade; 19. Bearing housing; 20. Exhaust pipe; 21. Flue gas pipe; 22. Superheater; 23. Steam main pipe; 24. Steam turbine; 25. Generator; 26. Reheater; 27. Economizer; 28. Exhaust fan; 29. ​​Support rod; 30. Gear; 31. Gear block; 32. Cylinder. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] As shown in the figure, a high-utilization kiln waste heat power generation system includes a waste heat boiler, a steam drum 4, a steam turbine 24, and a generator 25.

[0033] The waste heat boiler includes a furnace body 17, and a flue gas inlet pipe 11 is connected to the bottom of the furnace body 17. The flue gas inlet pipe 11 is connected to the tail end of the kiln, that is, the flue gas at the tail end of the kiln enters the interior of the waste heat boiler through the flue gas inlet pipe 11.

[0034] The furnace body 17 has a fixed cylinder 15 with an open top inside. The lower edge of the fixed cylinder 15 extends outward and is fixedly connected to the inner wall of the furnace body 17. The furnace body 17 has a rotatable movable cylinder 7 with an open bottom inside. The movable cylinder 7 is coaxially sleeved on the outside of the fixed cylinder 15. There are gaps between the inner wall of the movable cylinder 7 and the outer wall of the fixed cylinder 15, and between the outer wall of the movable cylinder 7 and the inner wall of the furnace body 17. A central rod 9 extends downward from the center of the movable cylinder 7. A continuous heat exchange tube 16 with a serpentine structure is provided in the area between the inner wall of the furnace body 17 and the outer wall of the movable cylinder 7, between the inner wall of the movable cylinder 7 and the outer wall of the fixed cylinder 15, and between the inner wall of the fixed cylinder 15 and the central rod 9. There are several heat exchange tubes 16, which are evenly distributed around the center of the furnace body 17. The lower end of the fixed cylinder 15 extends downward and is connected to the flue gas inlet pipe 11. The flow path of the working fluid in the heat exchange tube 16 is configured to be arranged in the overall opposite direction to the flow path of the flue gas.

[0035] With the aforementioned structure of the fixed cylinder 15, movable cylinder 7, and heat exchange tubes 16, the flue gas enters the furnace body 17 from the inlet pipe 11 and flows vertically upwards. Passing through the internal space of the fixed cylinder 15, it reaches the top of the fixed cylinder 15 and then diffuses outwards, entering the annular gap between the fixed cylinder 15 and the movable cylinder 7. Within this annular gap, the flue gas flows vertically downwards. When it reaches its lower limit, it flows upwards along a deflection path, entering the annular gap between the inner wall of the furnace body 17 and the outer wall of the movable cylinder 7. Subsequently, the flue gas continues to flow upwards in this gap and finally exits from the top of the furnace body 17 into the exhaust pipe 21. This achieves multiple deflection cycles and sufficient residence of the flue gas within the furnace body 17, allowing the heat exchange tubes 16, located in each deflection channel, to fully exchange heat with the flue gas, thus improving the overall heat exchange efficiency.

[0036] During this flow process, the working fluid in the heat exchange tube 16 flows along a path opposite to the overall flow direction of the flue gas, forming a counter-current heat exchange structure. This maintains a high temperature difference driving force throughout the heat exchange process, achieving higher heat exchange efficiency. At the same time, the baffle path of the flue gas inside the furnace body 17 increases the residence time, which is beneficial for the full absorption of heat energy in the high-temperature flue gas.

[0037] One end of the heat exchange tube 16 is connected to a circular liquid inlet pipe 6, and the other end is connected to a circular liquid outlet pipe 10. The liquid inlet pipe 6 is located in the area between the outer wall of the movable cylinder 7 and the inner wall of the furnace body 17, and is positioned away from the flue gas inlet pipe 11. The liquid outlet pipe 10 is located inside the fixed cylinder 15 and close to the flue gas inlet pipe 11. Specifically, the purpose of setting the liquid inlet pipe 6 is to allow the working fluid discharged from the steam drum 4 to first enter the liquid inlet pipe 6, and then be evenly distributed to the interior of each heat exchange tube 16, thereby ensuring that each heat exchange tube 16 can obtain a sufficient and uniform working fluid flow, and achieving overall balance in the heat exchange process. Correspondingly, the setting of the liquid outlet pipe 10 facilitates the collection of the heated working fluid in each heat exchange tube 16, which first flows into the liquid outlet pipe 10, and then is uniformly discharged to the steam-water separator 3 on the steam drum 4, making the collection and transportation of the working fluid smoother and reducing local resistance.

[0038] In addition, the liquid outlet pipe 10 is located in the center of the furnace body 17, close to the flue gas inlet pipe 11, so that the working fluid flowing out to the liquid outlet pipe 10 is in a relatively high flue gas temperature area, which can further absorb the heat of the high temperature flue gas before flowing out, thereby increasing the working fluid outlet temperature and improving steam production capacity and thermal energy utilization efficiency.

[0039] The liquid inlet main pipe 6 is connected to a liquid inlet pipe 5, and the end of the liquid inlet pipe 5 is connected to a steam drum 4. It is configured to introduce the working fluid in the steam drum 4 into the liquid inlet pipe 5. The steam drum 4 is used to store the working fluid (such as water or steam) generated by the boiler and to provide a stable working fluid pressure and flow rate for each heat exchange tube 16, thereby ensuring that the heat exchange tube 16 can uniformly obtain the working fluid and achieve efficient heat exchange. The liquid outlet main pipe 10 is connected to a liquid outlet pipe 8, and the end of the liquid outlet pipe 8 is installed on the steam-water separator 3 on the steam drum 4. It is configured to introduce the high-temperature working fluid into the steam-water separator 3. The steam-water separator 3 is used to separate the steam and liquid in the high-temperature working fluid flowing out of the heat exchange tube 16, ensuring that the steam delivered to the subsequent steam main pipe 23 and steam turbine 24 is dry saturated or superheated steam, thereby improving power generation efficiency and ensuring system operation stability.

[0040] Cleaning brushes 14 are installed on the inner wall, outer wall, and outer wall of the central rod 9 of the movable cylinder 7. The cleaning brushes 14 extend along the central axis of the furnace body 17 and extend towards the heat exchange tube 16. In this example, a row of cleaning brushes 14 distributed vertically is provided on the inner wall, outer wall, and outer wall of the central rod 9 to prevent the influence of flue gas flow when not in use. The cleaning brush 14 is made of high-temperature resistant stainless steel wire or nickel-based high-temperature alloy wire, which has good high-temperature resistance, wear resistance and corrosion resistance. It is mainly used to clean the surface of the heat exchange tube 16 during the rotation of the movable cylinder 7, remove dust particles attached to the flue gas in time, keep the surface of the heat exchange tube 16 clean, and thus ensure long-term stable heat exchange efficiency. In this example, the cleaning brush 14 only directly cleans one side of the outer wall of the heat exchange tube 16. Although the other side of the heat exchange tube 16 cannot be directly contacted, the cleaning brush 14 will generate slight vibration during the rotation cleaning process. This vibration can loosen and shake off the attached particles on the non-contact side of the heat exchange tube 16 without damaging the heat exchange tube 16, thus ensuring that the surface of the heat exchange tube 16 remains clean and the heat exchange efficiency is maintained for a long time.

[0041] The furnace body 17 is fixed with three support rods 29 evenly distributed around the center of the furnace body 17. A bearing seat 19 is installed in the middle of the support rod 29 and connected to the movable cylinder 7 through the bearing. To prevent the bearing from being easily damaged by flue gas, a dust cover can also be installed on the support rod 29. A fan blade 18 is installed on the upper outer wall of the movable cylinder 7. It also includes a gear 30 installed above the center of the movable cylinder 7. Inside the furnace body 17, there is a horizontally movable toothed block 31. When the toothed block 31 moves towards the center of the furnace body 17, it can mesh with the gear 30. When the toothed block 31 moves away from the center of the furnace body 17, the gear 30 separates from the toothed block 31. In this example, a cylinder 32 is installed outside the furnace body 17. The telescopic end of the cylinder 32 extends into the furnace body 17, or the cylinder 32 is installed entirely outside the furnace body 17. It is connected to the toothed block 31 by an extension rod. It is mainly used to drive the toothed block 31 to move horizontally. Under the action of the cylinder 32, the toothed block 31 meshes with the gear 30, which can lock the movable cylinder 7. At this time, the fan blade 18 will not rotate. When the toothed block 31 separates from the gear 30, the movable cylinder 7 is in the unlocked state. When the flue gas rises, it can drive the fan blade 18 and the movable cylinder 7 to rotate.

[0042] When the fan blade 18 is in a fixed state, the flue gas flows out from the annular gap between the movable cylinder 7 and the inner wall of the furnace body 17, and then flows upward at an angle through the gap of the fan blade 18 and is introduced into the exhaust pipe 21. This angled discharge method can make the flue gas flow more stable, reduce turbulence and local backflow at the flue gas outlet, and facilitate the smooth flow of air in the exhaust pipe 21, thereby reducing the exhaust resistance and improving the exhaust efficiency. At the same time, it avoids the flue gas from having too much impact on the top structure of the furnace body 17, ensuring the safe and stable operation of the system.

[0043] When the movable cylinder 7 is in the unlocked state, the flue gas exerts a force on the fan blade 18, causing the movable cylinder 7 to rotate, thereby driving the cleaning brush 14 to clean the heat exchange tube 16. The design of the fan blade 18 not only improves the flow state of the flue gas inside the furnace body 17, but also realizes the self-driven cleaning function of the cleaning brush 14, thereby significantly improving the overall thermal efficiency and operational reliability of the waste heat boiler.

[0044] The central axis of the flue gas inlet pipe 11 is tangent to the circumference of the fixed cylinder 15. A conical ash collection area 12 is formed at the lower end of the fixed cylinder 15, below the flue gas inlet pipe 11. An ash collection pipe 13 is connected to the bottom of the area between the fixed cylinder 15 and the inner wall of the furnace body 17, extending to the outside of the furnace body 17. Valves are installed below the ash collection area 12 and below the ash collection pipe 13. This arrangement allows for cyclone separation of flue gas entering the furnace body 17 via the ash collection area 12 of the fixed cylinder 15. This pre-separates larger particulate impurities in the flue gas before they enter the furnace body 17, reducing dust adhesion to the heat exchange zone and ensuring heat exchange efficiency. Compared to a separate cyclone separator, this method does not consume additional heat, avoiding heat loss. Furthermore, the separated ash can be periodically discharged through the ash collection pipe 13 and valves, facilitating centralized discharge and maintenance of impurities inside the furnace body 17.

[0045] The heat exchange tube 16 comprises, from the inside out, an inner layer 1601, a middle layer 1602, and an outer layer 1603. The middle layer 1602 is a phase change material layer, used to absorb heat from the flue gas when the temperature is high and release it when the temperature is low, thereby achieving heat buffering and storage and improving heat exchange efficiency. The inner layer 1601 is made of pressure-resistant and corrosion-resistant stainless steel 316, capable of withstanding the working pressure of steam or hot water, with good corrosion resistance and high thermal conductivity, allowing the heat absorbed by the outer layer 1603 and the middle layer 1602 to be efficiently transferred to the working fluid inside the tube. The outer layer 1603 is made of high-temperature resistant stainless steel 310 or a nickel-based alloy, capable of long-term stable operation in high-temperature flue gas environments, with excellent wear resistance, corrosion resistance, and oxidation resistance, and good thermal conductivity, allowing the heat from the flue gas to be fully transferred to the phase change material layer, maximizing heat exchange efficiency. Through the above three-layer structure, the heat exchange tube 16 can meet the requirements of pressure resistance, high temperature resistance, corrosion resistance, and heat storage, ensuring that it maintains efficient and reliable heat exchange performance during long-term operation.

[0046] The top of the furnace body 17 is connected to a flue pipe 21. Inside the flue pipe 21, a superheater 22, a reheater 26, and an economizer 27 are installed in sequence. The inlet of the superheater 22 is connected to an exhaust pipe 20, which is connected to a steam-water separator 3 installed on the steam drum 4. The outlet of the superheater 22 is connected to a steam main pipe 23, and the end of the steam main pipe 23 is connected to a steam turbine 24. The end of the steam turbine 24 is connected to a generator 25. The inlet of the reheater 26 is connected to the steam turbine 24, and the outlet is connected to the steam main pipe 23. The inlet of the economizer 27 is connected to the end of the steam turbine 24, and the outlet is connected to the kiln gas system. The kiln gas system is a gas pipeline and burner device used for combustion and heating in cement production kilns. The outlet of the economizer 27 is connected to it to preheat the kiln gas using the low-temperature steam or flue gas discharged from the end of the steam turbine 24, thereby reducing fuel consumption and improving the system's energy utilization rate.

[0047] The aforementioned flue gas pipe 21 is sequentially equipped with a superheater 22, a reheater 26, and an economizer 27. Its specific working principle is as follows: After the flue gas enters the flue gas pipe 21 from the top of the furnace body 17, it first passes through the superheater 22. The superheater 22 is connected to the steam-water separator 3 on the steam drum 4 via the exhaust pipe 20, further heating the steam separated from the steam-water separator 3 to high-temperature, high-pressure steam, thereby improving the steam energy utilization rate. Then, the steam exported from the middle section of the turbine 24 flows through the reheater 26, reheating the expanded steam at the outlet of the middle or high-pressure section of the turbine 24, increasing the steam temperature, reducing terminal condensation, and improving power generation efficiency. Finally, the steam exported from the end of the turbine 24 passes through the economizer 27, feeding the heat back to the kiln gas system, realizing the secondary utilization of flue gas waste heat, and reducing heat waste.

[0048] The exhaust pipe 21 is equipped with an exhaust fan 28. A dust removal device and a cooling tower are connected to the end of the exhaust pipe 21. It also includes a heat pipe 1, with the hot end of the heat pipe 1 located at the front end of the kiln and the cold end connected to a steam generator 2. The end of the steam generator 2 is connected to a steam-water separator 3. The dust removal device is mainly a bag filter or an electrostatic precipitator, used to remove dust and particulate impurities carried in the flue gas to ensure that the flue gas discharged into the atmosphere or downstream equipment is clean. The gas discharged from the dust removal device is further cooled by the cooling tower to protect downstream pipelines and equipment, while meeting environmental emission requirements.

[0049] In this highly efficient kiln waste heat power generation system, the high-temperature flue gas generated at the tail end of the kiln enters the waste heat boiler body 17 below the center through the flue gas inlet pipe 11, flows upward along the fixed cylinder 15, diffuses to the top, and then circulates in the annular gaps between the fixed cylinder 15 and the movable cylinder 7, and between the inner wall of the boiler body 17 and the outer wall of the movable cylinder 7, before finally being discharged from the top of the boiler body 17 into the exhaust pipe 21. During the flue gas flow, it exchanges heat countercurrently with the heat exchange tubes 16 arranged in the channel. The heat of the flue gas is fully absorbed by the working fluid. The working fluid is evenly distributed to each heat exchange tube 16 through the liquid inlet pipe 6 to absorb heat, and then collected by the liquid outlet pipe 10 and sent to the steam-water separator 3 on the steam drum 4 to separate steam and water, providing dry saturated or superheated steam for the steam turbine 24.

[0050] The movable cylinder 7 and cleaning brush 14 inside the furnace body 17 can rotate under the action of flue gas flow to clean the outer wall of the heat exchange tube 16. When cleaning is not performed (i.e., when the movable cylinder 7 does not rotate), the fan blade 18 structure can improve the flue gas flow, allowing the flue gas to enter the exhaust pipe 21 quickly and smoothly in a spiral manner, reducing the exhaust resistance. The ash collection area 12 at the bottom of the fixed cylinder 15 and the ash collection pipe 13 realize the cyclone separation and periodic discharge of particulate impurities in the flue gas.

[0051] The exhaust pipe 21 is equipped with a superheater 22, a reheater 26 and an economizer 27 in sequence to further heat the steam and recover heat from the low-temperature flue gas. At the same time, the exhaust fan 28, the dust removal device and the cooling tower control the emission and temperature of the flue gas. The heat pipe 1 can introduce the heat from the front end of the kiln into the steam generator 2 to supplement the steam, so as to make full use of the waste heat at the kiln head and kiln tail and improve the overall thermal efficiency and power generation efficiency of the system.

[0052] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-utilization kiln waste heat power generation system, characterized in that, This includes waste heat boilers, steam drums, steam turbines, and generators; The waste heat boiler includes a furnace body, with a flue gas inlet pipe connected to the bottom of the furnace body and connected to the tail end of the kiln. Inside the furnace body is a fixed cylinder with an open top, and the lower edge of the fixed cylinder extends outward and is fixedly connected to the inner wall of the furnace body. Inside the furnace body is a rotatable movable cylinder with an open bottom. The movable cylinder is coaxially sleeved on the outside of the fixed cylinder, and there are gaps between the inner wall of the movable cylinder and the outer wall of the fixed cylinder, and between the outer wall of the movable cylinder and the inner wall of the furnace body. A central rod extends downward from the center of the movable cylinder. A continuous heat exchange tube with a serpentine structure is provided in the area between the inner wall of the furnace body and the outer wall of the movable cylinder, between the inner wall of the movable cylinder and the outer wall of the fixed cylinder, and between the inner wall of the fixed cylinder and the central rod. There are several heat exchange tubes, which are evenly distributed around the center of the furnace body. The lower end of the fixed cylinder extends downward and is connected to the flue gas inlet pipe. The flow path of the working fluid inside the heat exchange tube is configured to be generally opposite to the flow path of the flue gas.

2. The high-utilization kiln waste heat power generation system according to claim 1, characterized in that, One end of the heat exchange tube is connected to a circular liquid inlet pipe, and the other end is connected to a circular liquid outlet pipe. The liquid inlet pipe is located in the area between the outer wall of the movable cylinder and the inner wall of the furnace, and is set away from the flue gas pipe; the liquid outlet pipe is located inside the fixed cylinder and close to the flue gas pipe.

3. A high-utilization kiln waste heat power generation system according to claim 2, characterized in that, The main inlet pipe is connected to an inlet pipe, and the end of the inlet pipe is connected to a steam drum, which is configured to introduce the working fluid in the steam drum into the inlet pipe; the main outlet pipe is connected to an outlet pipe, and the end of the outlet pipe is installed on the steam-water separator on the steam drum, which is configured to introduce the high-temperature working fluid into the steam-water separator.

4. A high-utilization kiln waste heat power generation system according to claim 1, characterized in that, Cleaning brushes are installed on the inner wall, outer wall, and outer wall of the central rod of the movable cylinder. The cleaning brushes extend along the central axis of the furnace body and are set towards the heat exchange tube.

5. A high-utilization kiln waste heat power generation system according to claim 1, characterized in that, The furnace body is fixed with a support rod inside. The middle position of the support rod is connected to the movable cylinder through a bearing. The upper outer wall of the movable cylinder is equipped with fan blades.

6. A high-utilization kiln waste heat power generation system according to claim 1, characterized in that, The central axis of the flue gas inlet pipe is tangent to the circumference of the fixed cylinder. A conical ash collection area is formed at the lower end of the fixed cylinder and below the flue gas inlet pipe. An ash collection pipe is connected to the bottom of the area between the fixed cylinder and the inner wall of the furnace, and the ash collection pipe extends to the outside of the furnace. Valves are installed below the ash collection area and below the ash collection pipe.

7. A high-utilization kiln waste heat power generation system according to claim 1, characterized in that, The heat exchange tube consists of an inner layer, a middle layer, and an outer layer arranged sequentially from the inside out, with the middle layer being a phase change material layer.

8. A high-utilization kiln waste heat power generation system according to claim 1, characterized in that, The top of the furnace body is connected to a flue pipe, inside which a superheater, a reheater, and an economizer are installed in sequence. The inlet of the superheater is connected to an exhaust pipe, which is connected to a steam-water separator installed on the steam drum. The outlet of the superheater is connected to a steam main pipe, the end of which is connected to a steam turbine, and the end of the steam turbine is connected to a generator. The inlet of the reheater is connected to the steam turbine, and the outlet is connected to the steam main pipe. The inlet of the economizer is connected to the end of the steam turbine, and the outlet is connected to the kiln gas system.

9. A high-utilization kiln waste heat power generation system according to claim 3, characterized in that, The exhaust pipe is equipped with an exhaust fan, and a dust removal device and a cooling tower are connected to the end of the exhaust pipe; it also includes a heat pipe, with the hot end of the heat pipe located at the front end of the kiln and the cold end connected to a steam generator, the end of the steam generator being connected to a steam-water separator.

10. A high-utilization kiln waste heat power generation system according to claim 1, characterized in that, It also includes a gear installed above the center of the movable cylinder, and a horizontally movable tooth block inside the furnace body. When the tooth block moves towards the center of the furnace body, it can mesh with the gear. When the tooth block moves away from the center of the furnace body, the gear separates from the tooth block.

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