Flue gas waste heat gradient utilization KC-ORC power generation system connecting structure with CO2 capturing function

Abstract

The utility model provides a flue gas waste heat gradient utilization KC-ORC power generation system with CO2 capture, which belongs to the technical field of energy environmental protection and comprises a KC high-temperature circulation loop, a KC cooling loop, an ORC low-temperature circulation loop, an ORC cooling loop and a CO2 capture device. The KC high-temperature circulation loop is connected with the KC cooling loop through a KC condenser, the ORC low-temperature circulation loop is connected with the ORC cooling loop through an ORC condenser, the KC high-temperature circulation loop is connected with the ORC low-temperature circulation loop through a heat regenerator, and the ORC low-temperature circulation loop is connected with the CO2 capturing device through a pipeline. The system adopts a KC-ORC combined structure to realize secondary recovery of flue gas waste heat, and is coupled with a CO2 capture system. The device solves the problem that only flue gas waste heat utilization is concerned in a traditional method, can realize integration and optimization of heat energy recovery and CO2 capture processes, and is beneficial to realizing emission reduction work of CO2 while promoting flue gas waste heat utilization.

Description

Technical Field

[0001] The utility model belongs to the technical field of energy and environmental protection, and specifically relates to a KC-ORC power generation system connection structure with CO2 capture and cascade utilization of flue gas waste heat. Background Art

[0002] With the acceleration of my country's industrialization process, industrial production has become the main source of energy consumption and environmental pollution. According to statistics, up to 50% of the energy consumed in industrial processes is lost to the environment in the form of flue gas, which not only causes a huge waste of energy, but also increases the environmental burden. Therefore, the rational and efficient recycling and utilization of industrial waste heat is of great significance to promoting my country's energy conservation and emission reduction work.

[0003] At present, flue gas waste heat recovery technology is mainly concentrated in conventional single-stage circulation systems. This system has limited recovery efficiency for medium and high temperature waste heat resources (such as cement kiln flue gas); after a single recovery, the flue gas temperature is still high, the remaining heat energy is not fully utilized, and the system's heat source matching and cycle adaptability are not strong; in order to further improve the waste heat recovery efficiency, the use of a cascade waste heat recovery power generation system has become an effective solution; through the combination of high-temperature circulation loops and low-temperature circulation loops, the cascade waste heat recovery system can more effectively recover heat energy of different grades, enhance heat source matching and adaptability, and give full play to the waste heat recovery potential of the circulation system.

[0004] In addition, with the increasingly serious problem of global climate change, the environmental pollution caused by the large amount of greenhouse gas CO2 produced in the process of primary energy consumption has also attracted widespread attention; my country, as the world's largest carbon emitter, faces huge pressure to reduce carbon emissions; especially after the clear proposal of the "carbon peak" and "carbon neutrality" goals, it has become particularly important to study and apply the capture technology of CO2 in exhaust gas. Utility Model Content

[0005] The purpose of the utility model is to provide a KC-ORC power generation system for cascade utilization of flue gas waste heat with CO2 capture, aiming to solve the problem in the prior art that traditional methods only focus on the utilization of flue gas waste heat.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a KC-ORC power generation system with CO2 capture and cascaded utilization of flue gas waste heat, comprising five components: a KC high-temperature circulation loop, a KC cooling loop, an ORC low-temperature circulation loop, an ORC cooling loop, and a CO2 capture device. The KC high-temperature circulation loop includes a KC preheater, a KC evaporator, a KC superheater, a KC condenser, a KC high-temperature regenerator, a KC turbine, a KC working pump, a KC generator, a regenerator, a separator, a mixer, and a throttle valve. The KC cooling loop includes a water pump a, a cooling tower a, and a gate valve a. The ORC low-temperature circulation loop includes an ORC preheater, an ORC evaporator, an ORC superheater, an ORC condenser, an ORC turbine, an ORC working pump, and an ORC generator. The ORC cooling loop includes a water pump b, a cooling tower b, and a gate valve b. The CO2 capture device includes an induced draft fan (IDF) a, an absorption tower, a rich liquid pump, a lean and rich liquid heat exchanger, a lean liquid cooler, a lean liquid pump, a regeneration tower, a regeneration gas cooler, a regeneration gas-liquid separator, a wash water pump, a recovery tower, an IDF fan (B), and a chimney. The absorption tower comprises a rich liquid storage tank, packing layer (A), packing layer (B), an absorption tower spray system, and an absorption tower demister. The regeneration tower comprises a lean liquid storage tank, packing layer (C), packing layer (D), a regeneration tower spray system, and a regeneration tower demister. The recovery tower comprises a liquid collection tank, packing layer (E), a recovery tower spray system, and a recovery tower demister. The KC high-temperature circulation loop is connected to the KC cooling loop via a KC condenser, the ORC low-temperature circulation loop is connected to the ORC cooling loop via an ORC condenser, the KC high-temperature circulation loop is connected to the ORC low-temperature circulation loop via a regenerator, and the ORC low-temperature circulation loop is connected to the CO2 capture device via a pipeline.

[0007] The flue gas waste heat cascade with CO2 capture utilizes the KC-ORC power generation system. As a preferred embodiment of the present invention, the flue gas cascade with CO2 capture utilizes the KC-ORC power generation system. The flue gas serves as a heat source and sequentially enters the KC superheater, KC evaporator and KC preheater of the KC high-temperature circulation loop. After cooling, it sequentially enters the ORC superheater, ORC evaporator and ORC preheater of the ORC low-temperature circulation loop, and then enters the absorption tower and recovery tower of the CO2 capture device. The purified flue gas from which CO2 has been removed is discharged into the atmosphere through the chimney.

[0008] The flue gas waste heat cascade with CO2 capture utilizes the KC-ORC power generation system as a preferred embodiment of the present invention. In the KC high-temperature circulation loop, the basic ammonia solution enters the KC preheater for preheating, and then passes through the KC evaporator to further absorb heat energy and become a two-phase mixture. After the two-phase mixture is superheated in the superheater, it is transported to the separator. In the separator, the mixture is separated into ammonia-rich steam and ammonia-lean liquid. The ammonia-rich steam discharged from the top of the separator is then expanded in the KC turbine and drives the KC generator to generate electricity, while the ammonia-lean liquid discharged from the bottom of the separator is transported to the KC high-temperature regenerator to release recoverable heat energy. After that, it is decompressed when flowing through the throttle valve, and then mixed with the exhaust steam discharged from the KC turbine in the mixer to form a gas-liquid mixture. After the gas-liquid mixture further releases heat through the regenerator, it is cooled into a liquid by cooling water when entering the KC condenser, and then transported to the KC working pump for pressurization, and then enters the KC high-temperature regenerator to absorb heat, completing the cycle of the KC system.

[0009] This flue gas waste heat cascade with CO2 capture utilizes a KC-ORC power generation system, which is a preferred embodiment of the present invention. In the KC cooling circuit, after the cooling water flows out of the outlet of cooling tower a, it enters water pump a for pressurization and is discharged from the outlet. It then enters the KC condenser. The heated cooling water is discharged from the outlet of the KC condenser, flows through gate valve a, and enters cooling tower a to start a new cycle. In the ORC low-temperature circulation circuit, the organic working fluid enters the ORC preheater and is preheated. It is then transported to the ORC evaporator to be converted into saturated steam, and further heated to a superheated state in the ORC superheater. It then flows into the ORC turbine to perform work, driving the ORC generator to generate electricity. The organic exhaust steam discharged from the ORC turbine outlet is cooled to liquid when passing through the ORC condenser, and then enters the ORC working pump for pressurization. Finally, the organic working fluid enters the regenerator to absorb heat, completing the cycle. In the ORC cooling circuit, after the cooling water flows out from the outlet of the cooling tower b, it enters the water pump b for pressurization and is discharged from the outlet, and then enters the ORC condenser. The heated cooling water is discharged from the outlet of the ORC condenser, flows through the gate valve b, and enters the cooling tower b to form a cycle. In the CO2 capture device, the low-temperature flue gas discharged from the outlet of the ORC preheater enters the induced draft fan a, which is connected to the lower part of the absorption tower. After entering the absorption tower, the flue gas rises along the axis of the tower and enters the packing layer a and the packing layer b in turn. The high concentration of CO2 in the flue gas reacts chemically with the amine solution sprayed from the top to the bottom by the absorption tower spray system and is absorbed. The absorption tower demister is placed on the upper part of the absorption tower to capture liquid droplets entrained in the flue gas; the rich liquid that has absorbed a large amount of CO2 flows back to the rich liquid storage tank and is pumped into the lean-rich liquid heat exchanger through the rich liquid pump. The lean-rich liquid heat exchanger The heat exchanger is connected to the upper part of the regeneration tower. The rich liquid entering the regeneration tower is atomized by the regeneration tower spray system and then falls, and passes through the packing layer d and packing layer c of the regeneration tower in turn. During the falling process, it exchanges heat with the vaporized steam. When the temperature of the reverse reaction is reached, the absorbed CO2 is separated from the absorbent, and the vaporized steam is cooled and condensed into droplets and falls back to the lean liquid storage tank. The lean liquid with low CO2 concentration enters the lean liquid pump from the bottom of the regeneration tower, and then enters the lean and rich liquid heat exchanger. After being cooled in the lean liquid cooler, it returns from the top of the absorption tower to continue the CO2 absorption work.

[0010] The KC-ORC power generation system with flue gas waste heat cascade utilization with CO2 capture is a preferred embodiment of the present invention. The separated CO2 passes through the regeneration tower demister and is discharged from the top of the regeneration tower. After being cooled by the regeneration gas cooler, it enters the regeneration gas-liquid separator. The finished CO2 is discharged from the top of the gas-liquid separator to become the final product. The low-concentration CO2 solution is discharged from the bottom of the gas-liquid separator and merges with the lean liquid at the outlet of the lean liquid cooler. The lean liquid is further cooled and then returned through the top of the absorption tower. At the same time, the flue gas discharged from the top of the absorption tower enters from the bottom of the recovery tower and passes through the After passing through the packing layer e of the recovery tower, the flue gas is cleaned by the desalted water of the recovery tower spray system during the rising process of the recovery tower, and then passes through the demister of the recovery tower to remove droplets in the gas, and then discharged from the top of the recovery tower, passes through the induced draft fan b and enters the chimney. The purified flue gas is discharged into the environment from the top of the chimney; the desalted water that has absorbed the solvent in the flue gas falls back to the washing water storage tank at the bottom of the recovery tower, and after passing through the washing water pump, part of the liquid returns through the top of the recovery tower to form a circulating washing loop to reduce the consumption of desalted water; another part of the liquid returns to the absorption tower through the top of the absorption tower to continue absorbing CO2 in the flue gas.

[0011] Compared with the prior art, the beneficial effects of the present invention are:

[0012] 1. This flue gas waste heat cascade utilization KC-ORC power generation system with CO2 capture utilizes a KC-ORC combined configuration, enabling secondary recovery of flue gas waste heat, further enabling full and effective utilization of flue gas waste heat. Compared to a single-stage cycle, the system's KC-ORC cascade configuration enhances the compatibility and adaptability of heat sources of varying grades, effectively expanding the temperature recovery range of the heat source.

[0013] 2. The KC-ORC power generation system with CO2 capture and the flue gas waste heat cascade utilization, coupled with the flue gas waste heat recovery system and the CO2 capture system, solves the problem of traditional methods that only focus on the utilization of flue gas waste heat. It can realize the integration and optimization of heat recovery and CO2 capture processes, which helps to achieve CO2 emission reduction while promoting the utilization of flue gas waste heat.

[0014] 3. This CO2-captured flue gas waste heat cascade utilizes a KC-ORC power generation system. In the KC high-temperature circulation loop, the high-temperature flue gas passes through the KC superheater, KC evaporator, and KC preheater, where it is gradually cooled and releases a large amount of heat energy. Subsequently, the flue gas, after initial cooling, enters the ORC low-temperature circulation loop, where it further releases excess heat energy in the ORC superheater, ORC evaporator, and ORC preheater. Adding a superheater to the two-stage waste heat recovery loop further improves the system's energy efficiency and delivers better thermal performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0016] Figure 1 This is a schematic diagram of the KC-ORC power generation system with cascade utilization of flue gas waste heat and CO2 capture of the present invention.

[0017] In the figure: 1-KC preheater; 2-KC evaporator; 3-KC superheater; 4-separator; 5-KC turbine; 6-KC generator; 7-mixer; 8-regenerator; 9-KC condenser; 10-KC working pump; 11-KC high-temperature regenerator; 12-throttle valve; 13-gate valve a; 14-cooling tower a; 15-water pump a; 16-ORC preheater; 17-ORC evaporator; 18-ORC superheater; 19-ORC turbine; 20-ORC generator; 21-ORC condenser; 22-ORC working pump; 23-gate valve b; 24-cooling tower b; 25-water pump b; 26-induced draft fan a; 27-absorption tower; 27-1-rich liquid storage tank; 27-2-Packing layer a; 27-3-Packing layer b; 27-4-Absorption tower spray system; 27-5-Absorption tower demister; 28-Rich liquid pump; 29-Lean and rich liquid heat exchanger; 30-Lean liquid cooler; 31-Lean liquid pump; 32-Regeneration tower; 32-1-Lean liquid storage tank; 32-2-Packing layer c; 32-3-Packing layer d; 32-4-Regeneration tower spray system; 32-5-Regeneration tower demister; 33-Regeneration gas cooler; 34-Regeneration gas-liquid separator; 35-Washing water pump; 36-Recovery tower; 36-1-Washing water storage tank; 36-2-Packing layer e; 36-3-Recovery tower spray system; 36-4-Recovery tower demister; 37-Draft fan b; 38-Chimney. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0019] Example

[0020] See also Figure 1 The utility model provides the following technical solutions: a KC-ORC power generation system with cascade utilization of flue gas waste heat and CO2 capture, including a KC high-temperature circulation loop, a KC cooling loop, an ORC low-temperature circulation loop, an ORC cooling loop and a CO2 capture device.

[0021] The KC high-temperature circulation loop is connected to the KC cooling loop via a KC condenser 9, the ORC low-temperature circulation loop is connected to the ORC cooling loop via an ORC condenser 21, the KC high-temperature circulation loop is connected to the ORC low-temperature circulation loop via a regenerator 8, and the ORC low-temperature circulation loop is connected to the CO2 capture device via a pipeline;

[0022] The system adopts a KC-ORC combined configuration to achieve secondary recovery of flue gas waste heat and is coupled with a CO2 capture system.

[0023] In this embodiment, the KC high-temperature circulation loop includes a KC preheater 1, a KC evaporator 2, a KC superheater 3, a separator 4, a KC turbine 5, a KC generator 6, a mixer 7, a regenerator 8, a KC condenser 9, a KC working pump 10 and a throttle valve 12.

[0024] In this embodiment, the basic ammonia solution is preheated in the KC preheater 1 and then enters the KC evaporator 2 to further absorb heat to become a two-phase mixture. After being superheated in the KC superheater 3, it is transported to the separator 4 and separated into ammonia-rich vapor and ammonia-lean liquid. The ammonia-rich vapor drives the KC turbine 5 and drives the KC generator 6 to generate electricity. The ammonia-lean liquid releases heat through the KC high-temperature regenerator 11 and is decompressed when passing through the throttle valve 12. It is then mixed with the exhaust steam discharged from the KC turbine 5 and then enters the regenerator 8 to release heat and is finally cooled to a liquid in the KC condenser 9. After being pressurized by the KC working pump 10, it returns to the KC high-temperature regenerator 11 to absorb heat.

[0025] In this embodiment, the KC cooling circuit consists of a water pump a15, a cooling tower a14, and a gate valve a13. After flowing out of the cooling tower a14 outlet, the cooling water is pressurized by the water pump a15 and passes through the KC condenser 9 to cool the working fluid in the KC circulation circuit. It then returns to the cooling tower a14 through the gate valve a13.

[0026] In this embodiment, the ORC low-temperature circulation loop includes an ORC preheater 16 , an ORC evaporator 17 , an ORC superheater 18 , an ORC turbine 19 , an ORC generator 20 , an ORC condenser 21 and an ORC working pump 22 .

[0027] In this embodiment, the recovered flue gas first exchanges heat with the KC circulation loop and passes through the KC superheater 3, KC evaporator 2 and KC preheater 1 of the KC circulation loop in sequence; the cooled flue gas then exchanges heat with the ORC circulation loop, and the flue gas discharged from the KC preheater 1 enters the ORC superheater 18, ORC evaporator 17 and ORC preheater 16 in sequence; the flue gas discharged from the ORC preheater 16 passes through the induced draft fan a26 and then enters the CO2 capture device, passes through the absorption tower 27 and the recovery tower 36 in sequence, and the purified flue gas is discharged into the atmosphere through the chimney 38.

[0028] In this embodiment, in the KC circulation loop, the basic ammonia solution is heated in the KC preheater 1 and then enters the KC evaporator 2. In the KC evaporator 2, the fluid is further heated to become a two-phase mixture and discharged from its outlet. It then enters the KC superheater 3 for superheating. The superheated two-phase mixture then enters the separator 4 and is separated into ammonia-rich vapor and ammonia-lean liquid. The ammonia-rich vapor is discharged from the top of the separator 4 and transported to the KC turbine 5 to expand and perform work and drive the KC generator 6 to generate electricity. The ammonia-lean liquid is discharged from the bottom of the separator 4 and enters the KC high-temperature regenerator 11 to release heat. When passing through the throttle valve 12, it becomes a low-pressure fluid and is then mixed with the exhaust steam discharged from the KC turbine 5 in the mixer 7 to form a gas-liquid mixture. The gas-liquid mixture discharged from the mixer 7 enters the regenerator 8 to release heat, is then transported to the KC condenser 9 to cool to a liquid, and its pressure is increased in the KC working pump 10. It then enters the KC high-temperature regenerator 11 to absorb heat, thereby completing the circulation of the KC loop.

[0029] In this embodiment, the KC cooling circuit is coupled to the KC circulation circuit via the KC condenser 9. After flowing out of the outlet of cooling tower a14, the cooling water is pressurized by water pump a15 and enters the KC condenser 9 to cool the KC fluid. It then enters the gate valve a13 and returns to the cooling tower a14 to begin self-circulation. The ORC circulation circuit is coupled to the KC circulation circuit via the regenerator 8. After being preheated in the ORC preheater 16, the organic working fluid enters the ORC evaporator 17 to further absorb heat and become saturated steam. It is then transported to the ORC superheater 18 to be heated to a superheated state. It then enters the ORC turbine 19 to perform work, driving the ORC generator 20 to generate electricity. The organic exhaust steam is discharged from the outlet of the ORC turbine 19 and enters the ORC condenser 21, where it is cooled to a liquid. It then enters the ORC working pump 22 to increase its pressure and is then transported to the regenerator 8 to absorb heat released by the KC circulation circuit, beginning a new cycle.

[0030] In this embodiment, the ORC cooling circuit is coupled to the ORC circulation circuit through the ORC condenser. After the cooling water flows out from the outlet of the cooling tower b24, it enters the water pump b25 for pressurization, and then enters the ORC condenser 21 to cool the organic working medium. The cooling water discharged from the outlet of the ORC condenser 21 passes through the gate valve b23 and returns to the cooling tower b24 to start a new cycle.

[0031] In this embodiment, the CO2 capture device is connected to the ORC preheater 16. After the flue gas is discharged from the ORC preheater 16, it passes through the induced draft fan a26 and enters the lower part of the absorption tower 27, then rises along the axis of the tower. During the process of passing through the packing layer a27-2 and the packing layer b27-3, the high concentration of CO2 in the flue gas reacts chemically with the amine solution sprayed from the absorption tower spray system 27-4 and is absorbed. Subsequently, the liquid droplets entrained in the flue gas are captured when passing through the absorption tower demister 27-5; and the rich liquid that has absorbed a large amount of CO2 flows back to the rich liquid storage tank 27-1, passes through the rich liquid pump 28 and enters the lean and rich liquid heat exchanger 29. The rich liquid that enters the regeneration tower through the top of the regeneration tower 32 is atomized by the regeneration tower spray system 32-4, and passes through the packing layer d32-3 and the packing layer c32-2 of the regeneration tower from top to bottom. The atomized rich liquid exchanges heat with the vaporized steam during the falling process.

[0032] In this embodiment, when the temperature of CO2 desorption is reached, the absorbed CO2 is separated from the absorbent, and the steam is cooled and condensed into droplets and falls back to the lean liquid storage tank 32-1. The lean liquid with a low CO2 concentration is pumped from the bottom of the regeneration tower 32 through the lean liquid pump 31, and then pumped into the lean-rich liquid heat exchanger 29. Then, it is cooled in the lean liquid cooler 30 and returned from the top of the absorption tower 27 to repeat the CO2 absorption work; the separated CO2 passes through the regeneration tower demister 32-4 and is discharged from the top of the regeneration tower 32. The top outlet of the regeneration tower 32 is connected to the inlet of the regeneration gas cooler 33. After being cooled by the regeneration gas cooler 33, it is then transported to the regeneration tower 32. The finished CO2 is discharged from the top of the gas-liquid separator 34 to become the final product, and the low-temperature and low-concentration CO2 solution is discharged from the bottom of the gas-liquid separator 34 and merged with the lean liquid discharged from the lean liquid cooler 30. The cooled mixed liquid returns through the top of the absorption tower 27; and the flue gas from which the CO2 has been separated and discharged from the top of the absorption tower 27 enters the tower from the bottom of the recovery tower 36. During the rising process through the packing layer e36-2, the flue gas is cleaned by the desalted water sprayed by the recovery tower spray system 36-3, and then passes through the recovery tower demister 36-4 to remove droplets in the gas, and is discharged from the top of the recovery tower 36 and enters the chimney through the induced draft fan b 37.

[0033] In this embodiment, the purified flue gas is discharged into the environment from the top of the chimney. At the same time, the desalted water that has absorbed the solvent in the flue gas falls back to the washing water storage tank 36-1 at the bottom of the recovery tower 36. The outlet of the washing water storage tank 36-1 is connected to the inlet of the washing water pump 35. Part of the liquid discharged from the outlet of the washing water pump 35 returns through the top of the recovery tower 36 to form a circulating washing loop; the other part returns to the absorption tower through the top of the absorption tower 27 to continue absorbing CO2 in the flue gas.

[0034] In this embodiment, the KC high-temperature circulation loop includes a KC preheater 1, a KC evaporator 2, a KC superheater 3, a separator 4, a KC turbine 5, a KC generator 6, a mixer 7, a regenerator 8, a KC condenser 9, a KC working pump 10, and a throttle valve 12. Each component is sequentially connected by pipes to form a closed circulation loop.

[0035] The KC cooling circuit includes a water pump a15, a cooling tower a14, and a gate valve a13. The outlet of the water pump a15 is connected to the KC condenser 9 via a pipeline. The outlet of the cooling tower a14 is connected to the inlet of the water pump a15 via a pipeline. The gate valve a13 is provided on the pipeline between the cooling tower a14 and the KC condenser 9.

[0036] The ORC low-temperature circulation loop includes an ORC preheater 16, an ORC evaporator 17, an ORC superheater 18, an ORC turbine 19, an ORC generator 20, an ORC condenser 21, and an ORC working pump 22. Each component is sequentially connected by pipes to form a closed circulation loop, and is connected to the KC high-temperature circulation loop through a regenerator 8;

[0037] The ORC cooling circuit includes a water pump b25, a cooling tower b24, and a gate valve b23. The outlet of the water pump b25 is connected to the ORC condenser 21 via a pipeline, and the outlet of the cooling tower b24 is connected to the inlet of the water pump b25 via a pipeline. The gate valve b23 is provided on the pipeline between the cooling tower b24 and the ORC condenser 21.

[0038] The CO2 capture device includes an induced draft fan a26, an absorption tower 27, a rich liquid pump 28, a lean and rich liquid heat exchanger 29, a lean liquid cooler 30, a lean liquid pump 31, a regeneration tower 32, a regeneration gas cooler 33, a regeneration gas-liquid separator 34, a washing water pump 35, a recovery tower 36, an induced draft fan b37 and a chimney 38. The absorption tower 27, the regeneration tower 32 and the recovery tower 36 are connected by pipes and pumps to form a circulation loop for CO2 capture and flue gas purification. The outlet of the ORC preheater 16 is connected to the inlet of the induced draft fan a26 through a pipe, and the outlet of the induced draft fan a26 is connected to the inlet of the absorption tower 27.

[0039] In this embodiment, the absorption tower 27 is provided with a packing layer a27-2, a packing layer b27-3, an absorption tower spray system 27-4 and an absorption tower demister 27-5, and the various components are fixedly connected by pipes and connectors; the regeneration tower 32 is provided with a packing layer c32-2, a packing layer d32-3, a regeneration tower spray system 32-4 and a regeneration tower demister 32-5, and the various components are also fixedly connected by pipes and connectors; the recovery tower 36 is provided with a packing layer e36-2, a recovery tower spray system 36-3 and a recovery tower demister 36-4, and the various components are also fixedly connected by pipes and connectors.

[0040] In this embodiment, the absorption tower 27 and the regeneration tower 32 are connected via a lean-rich liquid heat exchanger 29, the regeneration tower 32 and the lean liquid cooler 30 are connected via a pipeline, and the lean liquid cooler 30 and the absorption tower 27 are connected via a lean liquid pump 31 and a pipeline, thereby forming a circulation loop for rich liquid regeneration and lean liquid cooling.

[0041] In this embodiment, the top outlet of the regeneration tower 32 is connected to the regeneration gas cooler 33 through a pipeline, and the outlet of the regeneration gas cooler 33 is connected to the regeneration gas-liquid separator 34 through a pipeline. The top outlet of the regeneration gas-liquid separator 34 is used to discharge the finished CO2, and the bottom outlet is merged with the outlet of the lean liquid cooler 30 through a pipeline and then returns to the absorption tower 27.

[0042] In this embodiment, the top outlet of the recovery tower 36 is connected to the induced draft fan b37 through a pipeline, and the outlet of the induced draft fan b37 is connected to the chimney 38 to discharge the purified flue gas into the atmosphere; at the same time, a washing water storage tank 36-1 is provided at the bottom of the recovery tower 36, and the washing water storage tank 36-1 is connected to the recovery tower spray system 36-3 through a pipeline and a washing water pump 35 to form a circulating washing loop.

[0043] The working principle and operational flow of this utility model are as follows: This flue gas waste heat cascade with CO2 capture utilizes a KC-ORC power generation system. High-temperature industrial flue gas first enters the system through a pipeline. The flue gas, serving as a heat source, passes through the KC superheater 3, KC evaporator 2, and KC preheater 1 in the KC circulation loop, gradually decreasing its temperature. After being preheated in the KC preheater 1, the ammonia solution enters the KC evaporator 2 for further heating, forming a two-phase mixture. The two-phase mixture from the KC evaporator 2 enters the KC superheater 3 for superheating, then enters the separator 4 where it is separated into ammonia-rich vapor and ammonia-lean liquid. The ammonia-rich vapor is discharged from the top of the separator 4, driving the KC turbine 5 to produce work and drive the KC generator 6 to generate electricity. The ammonia-lean liquid is discharged from the bottom of the separator 4, releases heat through the KC high-temperature regenerator 11, and is decompressed by the throttle valve 12. It is then mixed with the exhaust steam from the KC turbine 5 in the mixer 7 to form a gas-liquid mixture. After releasing heat through the regenerator 8, the gas-liquid mixture is transported to the KC condenser 9 to be cooled into liquid, and then the pressure is increased by the KC working pump 10. Finally, it re-enters the KC high-temperature regenerator 11 to absorb heat, completing the KC cycle.

[0044] After cooling through the KC cycle, the flue gas continues into the ORC circulation loop, passing through the ORC superheater 18, ORC evaporator 17, and ORC preheater 16. After being preheated in the ORC preheater 16, the organic working fluid enters the ORC evaporator 17, where it absorbs further heat and becomes saturated steam. It then enters the ORC superheater 18 and is heated to a superheated state. The superheated steam enters the ORC turbine 19, where it expands and generates work, driving the ORC generator 20 to generate electricity. The organic exhaust steam is discharged from the outlet of the ORC turbine 19 and enters the ORC condenser 21, where it is cooled to a liquid. It is then pressurized by the ORC working pump 22 and transported to the regenerator 8, where it absorbs heat from the KC cycle, beginning a new cycle.

[0045] Low-temperature flue gas from the ORC preheater 16 enters absorption tower 27 via induced draft fan a26. Within absorption tower 27, the CO2 in the flue gas reacts chemically with the amine solution in packing layers a27-2 and b27-3, where it is absorbed and forms a rich liquid. The rich liquid is stored in rich liquid storage tank 27-1 and pumped via rich liquid pump 28 to the lean-rich liquid heat exchanger 29. The rich liquid then enters regeneration tower 32, where it is atomized by the regeneration tower spray system 32-4 and then falls downward. It then countercurrently contacts the rising steam between packing layers c32-2 and d32-3, releasing the CO2. The released CO2 gas passes through the regeneration tower demister 32-5 to remove entrained liquid droplets. It then enters the regeneration gas cooler 33 for cooling. The pure CO2 product is then separated by the regeneration gas-liquid separator 34.

[0046] Lean liquid with a low CO2 concentration flows out of the bottom of regeneration tower 32, passes through lean liquid pump 31 and lean liquid cooler 30, and then returns to absorption tower 27 to continue absorbing CO2. The purified flue gas discharged from the top of absorption tower 27 enters recovery tower 36, where it is cleaned with demineralized water by recovery tower spray system 36-3. It then passes through recovery tower demister 36-4 to remove droplets from the gas. Finally, it is discharged into chimney 38 through induced draft fan b37 and discharged into the atmosphere.

[0047] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A KC-ORC power generation system connection structure with CO2 capture and cascade utilization of flue gas waste heat, characterized by: include: A KC high-temperature circulation loop comprises a KC preheater (1), a KC evaporator (2), a KC superheater (3), a separator (4), a KC turbine (5), a KC generator (6), a mixer (7), a regenerator (8), a KC condenser (9), a KC working pump (10) and a throttle valve (12), wherein the components are sequentially connected by pipelines to form a closed circulation loop; A KC cooling circuit includes a water pump a (15), a cooling tower a (14) and a gate valve a (13), wherein the outlet of the water pump a (15) is connected to the KC condenser (9) via a pipeline, the outlet of the cooling tower a (14) is connected to the inlet of the water pump a (15) via a pipeline, and the gate valve a (13) is provided on the pipeline between the cooling tower a (14) and the KC condenser (9); An ORC low-temperature circulation loop comprises an ORC preheater (16), an ORC evaporator (17), an ORC superheater (18), an ORC turbine (19), an ORC generator (20), an ORC condenser (21) and an ORC working pump (22), wherein the components are sequentially connected by pipelines to form a closed circulation loop, and are connected to the KC high-temperature circulation loop via a regenerator (8); The ORC cooling circuit includes a water pump b (25), a cooling tower b (24) and a gate valve b (23), wherein the outlet of the water pump b (25) is connected to the ORC condenser (21) through a pipeline, the outlet of the cooling tower b (24) is connected to the inlet of the water pump b (25) through a pipeline, and the gate valve b (23) is provided on the pipeline between the cooling tower b (24) and the ORC condenser (21); A CO2 capture device comprises an induced draft fan a (26), an absorption tower (27), a rich liquid pump (28), a lean and rich liquid heat exchanger (29), a lean liquid cooler (30), a lean liquid pump (31), a regeneration tower (32), a regeneration gas cooler (33), a regeneration gas-liquid separator (34), a washing water pump (35), a recovery tower (36), an induced draft fan b (37) and a chimney (38). The absorption tower (27), the regeneration tower (32) and the recovery tower (36) are connected by pipes and pumps to form a circulation loop for CO2 capture and flue gas purification. The outlet of the ORC preheater (16) is connected to the inlet of the induced draft fan a (26) through a pipe, and the outlet of the induced draft fan a (26) is connected to the inlet of the absorption tower (27).

2. The KC-ORC power generation system connection structure for cascaded utilization of flue gas waste heat with CO2 capture according to claim 1 is characterized by: The absorption tower (27) is provided with a packing layer a (27-2), a packing layer b (27-3), an absorption tower spray system (27-4) and an absorption tower demister (27-5), and the various components are fixedly connected through pipes and connectors.

3. The KC-ORC power generation system connection structure for cascaded utilization of flue gas waste heat with CO2 capture according to claim 2 is characterized by: The regeneration tower (32) is provided with a packing layer c (32-2), a packing layer d (32-3), a regeneration tower spray system (32-4) and a regeneration tower demister (32-5), and each component is also fixedly connected by pipes and connectors.

4. The KC-ORC power generation system connection structure for cascaded utilization of flue gas waste heat with CO2 capture according to claim 3 is characterized by: The recovery tower (36) is provided with a packing layer e (36-2), a recovery tower spray system (36-3) and a recovery tower demister (36-4), and the various components are also fixedly connected by pipes and connectors.

5. The KC-ORC power generation system connection structure for cascaded utilization of flue gas waste heat with CO2 capture according to claim 4 is characterized by: The absorption tower (27) and the regeneration tower (32) are connected via a lean-rich liquid heat exchanger (29), and the regeneration tower (32) and the lean liquid cooler (30) are connected via a pipeline.

6. The KC-ORC power generation system connection structure for cascaded utilization of flue gas waste heat with CO2 capture according to claim 5 is characterized by: The lean liquid cooler (30) is connected to the absorption tower (27) via a lean liquid pump (31) and a pipeline to form a circulation loop for rich liquid regeneration and lean liquid cooling.

7. The KC-ORC power generation system connection structure for cascaded utilization of flue gas waste heat with CO2 capture according to claim 6 is characterized by: The top outlet of the regeneration tower (32) is connected to the regeneration gas cooler (33) through a pipeline, and the outlet of the regeneration gas cooler (33) is connected to the regeneration gas-liquid separator (34) through a pipeline.

8. The KC-ORC power generation system connection structure for cascaded utilization of flue gas waste heat with CO2 capture according to claim 7 is characterized by: The top outlet of the regenerated gas-liquid separator (34) is used to discharge finished CO2, and the bottom outlet is combined with the outlet of the lean liquid cooler (30) through a pipeline and then returns to the absorption tower (27).

9. The KC-ORC power generation system connection structure for cascaded utilization of flue gas waste heat with CO2 capture according to claim 8 is characterized by: The top outlet of the recovery tower (36) is connected to the induced draft fan b (37) through a pipeline, and the outlet of the induced draft fan b (37) is connected to the chimney (38) to discharge the purified flue gas into the atmosphere.

10. The KC-ORC power generation system connection structure for cascaded utilization of flue gas waste heat with CO2 capture according to claim 9 is characterized by: A washing water storage tank (36-1) is provided at the bottom of the recovery tower (36), and the washing water storage tank (36-1) is connected to the recovery tower spray system (36-3) through a pipeline and a washing water pump (35) to form a circulating washing loop.

Images