Compressor interstage waste heat refrigeration energy-saving device capable of capturing carbon dioxide

Abstract

The utility model discloses a compressor interstage waste heat refrigeration energy-saving device capable of capturing carbon dioxide. A plurality of heat exchangers which are connected in series comprise a waste heat water heater, a cooling water cooler and a chilled water cooler. An exhaust pipe of the compressor sequentially passes through the heat exchangers connected in series to form multi-stage cooling; a first refrigerant circulation loop is formed between the waste heat water heater and the absorption type waste heat refrigerating machine, and the first refrigerant circulation loop serves as a driving heat source of the absorption type waste heat refrigerating machine; a second refrigerant circulation loop is formed between the chilled water cooler and the absorption type waste heat refrigerator; and the circulating water loop is connected to the cooling water cooler. According to the compressor interstage waste heat refrigeration energy-saving device capable of capturing the carbon dioxide, a set of sectional heat exchanger is additionally arranged at an outlet of the CO2 compressor, a lithium bromide absorption refrigerator is matched, waste heat of high-temperature CO2 compressed gas with the temperature ranging from 110 DEG C to 200 DEG C is used for preparing cold energy, the CO2 compressed gas is cooled, and the refrigerating capacity requirement of electric refrigeration at the rear section of the technology is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of waste heat utilization, and in particular to a compressor interstage waste heat refrigeration energy-saving device for capturing carbon dioxide. Background Art

[0002] Carbon capture and storage (CCS) is a technology that captures carbon dioxide (CO2) produced by large-scale power plants and stores it using various methods to prevent its release into the atmosphere. This technology is considered the most economical and feasible way to reduce greenhouse gas emissions and mitigate global warming on a large scale in the future.

[0003] Carbon capture, utilization, and storage (CCUS) is a new development in CCS (carbon capture and storage) technology. It purifies carbon dioxide emitted during production and then recycles it into new production processes, rather than simply storing it. Compared to CCS, CCUS can transform carbon dioxide into a resource, generate economic benefits, and is more practical.

[0004] In the compression system before carbon sequestration, a compressor is typically used to compress and liquefy the high-purity carbon dioxide gas captured by the original process. The compressed gas reaches a temperature of approximately 170°C and needs to be further cooled to -22°C for liquefaction before being transferred to storage tanks. During this process, the compressor generates a large amount of heat after compressing the gas. Directly cooling this heat through the cooling system would result in a large amount of heat being released into the air, which not only poses a certain risk to the environment but also wastes resources.

[0005] In view of the above, it is necessary to propose a compressor interstage waste heat refrigeration energy-saving device with carbon dioxide capture to solve the above problems. Utility Model Content

[0006] The purpose of the utility model is to overcome the defects in the prior art and provide a compressor interstage waste heat refrigeration energy-saving device for capturing carbon dioxide.

[0007] To achieve the above purpose, the technical solution of the utility model is as follows:

[0008] A carbon dioxide capture compressor interstage waste heat refrigeration energy-saving device is characterized in that it includes a compressor, an integrated heat exchanger, and an absorption waste heat refrigerator. The absorption waste heat refrigerator provides a cold medium as a cold source in the integrated heat exchanger, and the compressor provides compressed gas as a heat source, forming a heat exchange between the cold source and the heat source; the absorption waste heat refrigerator forms at least one cold source, and the heat source gas formed by the compressor exhaust pipe is heat-exchanged with at least one cold source medium in the integrated heat exchanger, forming at least one level of cooling heat exchange for the heat source.

[0009] Furthermore, a three-stage cooling heat exchange is formed in the integrated heat exchanger, including a waste water heater, a cooling water cooler, and a chilled water cooler; a first refrigerant circulation loop is formed between the waste water heater and the absorption waste heat refrigerator, and the first refrigerant circulation loop serves as a driving heat source for the absorption waste heat refrigerator; a second refrigerant circulation loop is formed between the chilled water cooler and the absorption waste heat refrigerator; and a circulating water loop connected to the cooling water cooler is also included.

[0010] Furthermore, the absorption waste heat refrigeration machine includes an absorber, a generator, a condenser, and an evaporator;

[0011] The first refrigerant circulation loop includes a first circulating water supply and a first circulating water return. The first circulating water supply is connected to the heat source inlet S1 of the generator, and the heat source outlet S2 of the generator is connected to the first circulating water return. The other end of the first circulating water supply is connected to the pipe side water outlet S3 of the waste hot water heater, and the other end of the first circulating water return is connected to the pipe side water inlet S4 of the waste hot water heater.

[0012] The second refrigerant circulation loop includes a second circulation supply water and a second circulation return water. The second circulation supply water is connected to the heat source inlet W1 of the evaporator, and the heat source outlet W2 of the evaporator is connected to the second circulation return water; the other end of the second circulation supply water is connected to the pipe side water outlet W3 of the chilled water cooler, and the other end of the second circulation return water is connected to the pipe side water inlet W4 of the chilled water cooler.

[0013] Furthermore, the circulating water loop includes circulating water supply and circulating water return, the circulating water supply is connected to the pipe side water inlet L1 of the cooling water cooler, and the circulating water return is connected to the pipe side water return L2 of the cooling water cooler.

[0014] Furthermore, the circulating water supply is provided with a water supply branch pipe, and the circulating water return is provided with a water return branch pipe. The water supply branch pipe is connected to the absorption waste heat refrigerator, and passes through the absorber and condenser in sequence and then flows back to the circulating water return from the water return branch pipe.

[0015] Furthermore, a waste heat water pump is provided on the first circulating return water pipeline; and a refrigerant water pump is provided on the second circulating water supply pipeline.

[0016] Furthermore, a temperature-controlled three-way valve is provided on the first circulating water supply pipeline, a branch of the temperature-controlled three-way valve is connected to the inlet pipe of the waste heat water pump, a first cross-line pipe is provided at the front end of the temperature-controlled three-way valve, the other end of the first cross-line pipe is connected to the inlet pipe, and a second cross-line pipe is provided on the temperature-controlled three-way valve, the two ends of the second cross-line pipe are respectively connected to the front and rear ends of the temperature-controlled three-way valve.

[0017] Furthermore, water supply pipelines are provided at the front ends of the waste heat water pump and the refrigerant water pump.

[0018] The advantages and beneficial effects of the present invention are as follows: the present invention is a compressor interstage waste heat refrigeration energy-saving device for carbon dioxide capture, which adds a set of segmented heat exchangers at the outlet of the CO2 compressor and is equipped with a lithium bromide absorption refrigerator. It uses the waste heat of the high-temperature CO2 compressed gas of 110~200℃ to generate cold capacity, thereby cooling the CO2 compressed gas and reducing the cooling capacity demand of the electric refrigeration in the latter part of the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the flow of a compressor interstage waste heat refrigeration energy-saving device for carbon dioxide capture in the utility model;

[0020] Figure 2 It is a schematic diagram of the absorption waste heat refrigeration machine of the utility model;

[0021] Figure 3 It is a schematic diagram of multiple circulation loops forming an integrated heat exchanger;

[0022] In the figure: 1. Absorption waste heat chiller; 2. Waste water heater; 3. Cooling water cooler; 4. Chilled water cooler; 5. Exhaust pipe; 6. First refrigerant circulation loop; 7. Second refrigerant circulation loop; 8. Circulating water loop; 9. Absorber; 10. Generator; 11. Condenser; 12. Evaporator; 13. First circulation water supply; 14. First circulation water return; 15. Heat source inlet S1; 16. Heat source outlet S2; 17. Pipeline water outlet S3; 18. Pipeline water inlet S4; 19. Second circulation water supply; 20. Secondary circulation return water; 21. Heat source inlet end W1; 22. Heat source outlet end W2; 23. Pipeline outlet W3; 24. Pipeline inlet W4; 25. Circulating water supply; 26. Circulating water return; 27. Pipeline inlet L1; 28. Pipeline return water outlet L2; 29. ​​Supply water branch pipe; 30. Return water branch pipe; 31. Waste water pump; 32. Refrigerant water pump; 33. Temperature control three-way valve; 34. Branch road; 35. Inlet pipe; 36. First cross-line pipe; 37. Second cross-line pipe; 38. Make-up water pipeline; 39. Integrated heat exchanger. DETAILED DESCRIPTION

[0023] The following embodiments are used to further describe the specific embodiments of the present invention in conjunction with the accompanying drawings and examples. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0024] A carbon dioxide capture compressor interstage waste heat refrigeration energy saving device, such as Figure 1 、 2 As shown, it includes a compressor, an integrated heat exchanger 39, and an absorption type waste heat refrigerator 1. The integrated heat exchanger is provided with a plurality of cooling medium circulation loops; the heat source gas in the compressor exhaust pipe exchanges heat with each cooling medium circulation loop of the integrated heat exchanger in turn to form multi-stage cooling; the temperature of the process material at the outlet of the compressor is about 170-180°C. According to the changes in the working conditions, the gas flow rate is 65000-114000 kg / h. In the process, the gas needs to be cooled and formed into liquid carbon dioxide for collection. Its higher heat can be utilized. In this embodiment, the tail gas temperature of 170-180°C is utilized, and the absorption type waste heat refrigerator 1 is used to cool itself so that the carbon dioxide gas is finally reduced to about 8°C, thereby achieving better utilization of waste heat.

[0025] As an example, Figure 1 As shown, multiple circulation loops in the integrated heat exchanger form a waste water heater 2, a cooling water cooler 3, and a chilled water cooler 4. The above heat exchangers are independently set to form three heat exchangers, such as Figure 1 As shown in the flow chart; the exhaust pipe 5 of the compressor passes through each heat exchanger in series to form a multi-stage cooling.

[0026] As another embodiment, the integrated heat exchanger can also be provided in the form of a large heat exchanger as a whole, such as Figure 3 As shown, the exhaust pipe is connected to the shell side of the integrated heat exchanger 39, and then multiple circulation loops are sequentially arranged inside the integrated heat exchanger 39 to form a waste hot water heater 2, a cooling water cooler 3, and a chilled water cooler 4 respectively; this embodiment can reduce the number of heat exchangers set up, and achieve the same multi-stage heat exchange effect, reducing the space occupied by the equipment. In actual use, the number of circulation loops formed by the cooling medium in the integrated heat exchanger can be increased or decreased according to the production capacity and other requirements of the process production, thereby forming different levels of cooling and heat exchange for the heat source in the integrated heat exchanger. In the case of reduction, for example, only the waste hot water heater 2 or the cooling water cooler 3 or the chilled water cooler 4 is used; in the case of increase, for example, multiple groups of absorption waste heat refrigerators can be added, and several cold sources formed by different groups of absorption waste heat refrigerators can be introduced into the same integrated heat exchanger 39, thus forming a ratio Figure 3 There are even more multi-stage cooling situations in the circulation loop.

[0027] like Figure 1 As shown, a separate heat exchanger is provided to introduce the specific flow direction of the process medium. The high-temperature carbon dioxide gas pressurized and discharged by the compressor first enters the shell side of the waste water heater 2 for primary cooling. A first refrigerant circulation loop 6 is formed between the waste water heater 2 and the absorption type waste heat refrigerator 1. The first refrigerant circulation loop 6 enters the tube side of the waste water heater 2. The two materials exchange heat with each other to reduce the temperature of the carbon dioxide gas. In this embodiment, after cooling by the waste water heater 2, the carbon dioxide temperature drops to about 125°C. Correspondingly, the process medium in the first refrigerant circulation loop 6 is heated and enters the waste heat refrigerator as a driving heat source, realizing the utilization of waste heat, so that the first refrigerant circulation loop 6 is used as the driving heat source of the absorption type waste heat refrigerator 1.

[0028] Furthermore, the carbon dioxide gas after passing through the waste water heater 2 enters the cooling water cooler 3, forming a secondary cooling of the carbon dioxide gas, and also includes a circulating water loop 8 connected to the cooling water cooler 3; this stage uses circulating cooling water to cool the carbon dioxide, and the carbon dioxide gas enters the shell side of the cooling water cooler 3, and the circulating water enters the tube side of the cooling water cooler 3 to realize heat exchange.

[0029] Then, the carbon dioxide gas enters the chilled water cooler 4 to achieve three-stage cooling, and the carbon dioxide gas enters the shell side of the cooling water cooler 3. A second refrigerant circulation loop 7 is formed between the chilled water cooler 4 and the absorption waste heat refrigerator 1; the second refrigerant circulation loop 7 is connected to the shell side of the chilled water cooler 4, and the absorption waste heat refrigerator 1 uses the heat energy absorbed from the waste water heater 2 to cool the process medium in the second refrigerant circulation loop 7, and uses the cooled process medium to perform a third-stage cooling of the carbon dioxide, so that the final temperature of the carbon dioxide drops to about 8°C after the three-stage cooling, thereby realizing effective waste heat utilization.

[0030] Specifically, such as Figure 2 As shown, the absorption waste heat refrigerator 1 includes an absorber 9, a generator 10, a condenser 11, and an evaporator 12; the connection relationship between the waste heat refrigerator and the external process pipeline in this embodiment is as follows: the first refrigerant circulation loop 6 includes a first circulating water supply 13 and a first circulating return water 14, the first circulating water supply 13 is connected to the heat source inlet end S115 of the generator 10, and the heat source outlet end S216 of the generator 10 is connected to the first circulating return water 14, and the process medium in the first refrigerant circulation loop 6 heated by the high-temperature carbon dioxide gas enters the generator 10 as a heat source, so that the water in the generator 10 is evaporated, and its temperature is reduced when it flows out from the heat source outlet end S216, and is sent to the waste hot water heater 2 for circulation again, and a waste hot water pump 31 is provided on the first circulating return water pipeline 14; the waste hot water pump 31 is used to realize the forced circulation of the first refrigerant circulation loop 6.

[0031] As an improvement, a temperature-controlled three-way valve 33 is installed on the first circulating water supply pipeline 13. A branch 34 of the temperature-controlled three-way valve 33 is connected to the inlet pipe 35 of the waste heat pump 31. The temperature-controlled three-way valve 33 is a remotely controlled valve that can control the opening of the branch 34, thereby diverting a portion of the water back to the inlet pipe 35, thereby reducing the flow of hot water entering the generator 10 and achieving heat control on the first circulating water return pipeline 14. Process material: The outlet temperature of the process material at the raw material compressor is maintained at no more than 8°C under minimum operating conditions (60%), normal operating conditions (100%), and maximum operating conditions (105%). A first cross-line pipe 36 is installed at the front end of the temperature-controlled three-way valve 33. The other end of the first cross-line pipe 36 is connected to the inlet pipe 35. This pipe has a similar function to the branch 34. This first cross-line pipe 36 is designed for on-site manual control and is equipped with a manual control valve that can be operated locally by on-site personnel. The temperature-controlled three-way valve 33 is provided with a second cross-line pipe 37, the two ends of which are connected to the front and rear ends of the temperature-controlled three-way valve 33. The second cross-line pipe 37, in conjunction with a pipe-cutting valve installed on the pipeline, can be manually controlled to isolate the temperature-controlled three-way valve 33, facilitating replacement operations during maintenance. Corresponding to the wastewater heater 2, the other end of the first circulating water supply 13 is connected to the pipe-side water outlet S317 of the wastewater heater 2, and the other end of the first circulating water return 14 is connected to the pipe-side water inlet S418 of the wastewater heater 2, thereby forming the first refrigerant circulation loop 6.

[0032] Furthermore, the circulating water loop 8 includes a circulating water inlet 25 and a circulating water return 26. The circulating water inlet 25 is connected to the pipe side water inlet L127 of the cooling water cooler 3, and the circulating water return 26 is connected to the pipe side return water inlet L228 of the cooling water cooler 3. This stage directly uses cooling water cooling to cool the carbon dioxide gas. The inlet temperature of the circulating cooling water is about 32°C, and the outlet temperature is about 42°C. The circulating cooling water flows through the pipe side of the cooling water cooler 3, and the carbon dioxide gas passes through the shell side. In addition, a water inlet branch pipe 29 is provided at the circulating water inlet 25, and a water return branch pipe 30 is provided at the circulating water return 26, as shown in FIG. Figure 2 As shown, the water supply branch pipe 29 is connected to the absorption waste heat chiller 1, passes through the absorber 9 and condenser 11 in sequence, and then flows back to the circulating water return 26 through the return water branch pipe 30. The circulating water enters the absorber 9 and condenser 11 of the waste heat chiller as a cooling medium for circulation cooling.

[0033] The second refrigerant circulation loop 7 includes a second circulating water supply 19 and a second circulating return water 20. The second circulating water supply 19 is connected to the heat source inlet W1 21 of the evaporator 12, and the heat source outlet W2 22 of the evaporator 12 is connected to the second circulating return water 20. A refrigerant water pump 32 is provided in the second refrigerant circulation loop 7 as a forced circulation pump for the refrigerant. The refrigerant water enters the heat source inlet W1 21 at a temperature of approximately 15°C. After cooling in the evaporator 12, the temperature drops to approximately 5°C. This refrigerant water is then delivered through the second circulating return water 20 pipeline to the pipe-side water inlet W4 24 of the chilled water cooler 4, where it undergoes tertiary cooling of the carbon dioxide gas, reducing its final temperature to approximately 8°C before being discharged. The other end of the second circulating water supply 19 is connected to the pipe-side water outlet W3 23 of the chilled water cooler 4, forming the second refrigerant circulation loop 7.

[0034] The front ends of the waste heat water pump 31 and the refrigerant water pump 32 are both provided with a water supply pipeline 38; Figure 1 As shown, a water supply line 38 is provided on the circulation loop to supplement the refrigerant water consumption in the system.

[0035] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A carbon dioxide capture compressor interstage waste heat refrigeration energy-saving device, characterized in that: The invention comprises a compressor, an integrated heat exchanger, and an absorption type waste heat refrigeration machine (1), wherein the absorption type waste heat refrigeration machine (1) provides a cold medium as a cold source in the integrated heat exchanger, and the compressor provides compressed gas as a heat source, thereby forming a heat exchange between the cold source and the heat source; the absorption type waste heat refrigeration machine (1) forms at least one cold source, and the heat source gas formed by the compressor exhaust pipe (5) exchanges heat with at least one cold source medium in the integrated heat exchanger, thereby forming at least one level of cooling heat exchange for the heat source.

2. The carbon dioxide capture compressor interstage waste heat refrigeration energy-saving device according to claim 1, characterized in that: A three-stage cooling heat exchange system is formed in the integrated heat exchanger, including a waste water heater (2), a cooling water cooler (3), and a chilled water cooler (4); a first refrigerant circulation loop (6) is formed between the waste water heater (2) and the absorption type waste heat refrigerator (1), and the first refrigerant circulation loop (6) serves as a driving heat source for the absorption type waste heat refrigerator (1); a second refrigerant circulation loop (7) is formed between the chilled water cooler (4) and the absorption type waste heat refrigerator (1); and a circulating water loop (8) connected to the cooling water cooler (3) is also included.

3. The carbon dioxide capture compressor interstage waste heat refrigeration energy-saving device according to claim 2, characterized in that: The absorption waste heat refrigeration machine (1) comprises an absorber (9), a generator (10), a condenser (11), and an evaporator (12); The first refrigerant circulation loop (6) includes a first circulating water supply (13) and a first circulating water return (14), wherein the first circulating water supply (13) is connected to the heat source inlet end S1 (15) of the generator (10), and the heat source outlet end S2 (16) of the generator (10) is connected to the first circulating water return (14); the other end of the first circulating water supply (13) is connected to the pipe side water outlet S3 (17) of the waste hot water heater (2), and the other end of the first circulating water return (14) is connected to the pipe side water inlet S4 (18) of the waste hot water heater (2); The second refrigerant circulation loop (7) includes a second circulating water supply (19) and a second circulating return water (20), wherein the second circulating water supply (19) is connected to the heat source inlet end W1 (21) of the evaporator (12), and the heat source outlet end W2 (22) of the evaporator (12) is connected to the second circulating return water (20); the other end of the second circulating water supply (19) is connected to the pipe side water outlet W3 (23) of the chilled water cooler (4), and the other end of the second circulating return water (20) is connected to the pipe side water inlet W4 (24) of the chilled water cooler (4).

4. The carbon dioxide capture compressor interstage waste heat refrigeration energy-saving device according to claim 3, characterized in that: The circulating water circuit (8) includes a circulating water supply (25) and a circulating water return (26), wherein the circulating water supply (25) is connected to the pipe-side water inlet L1 (27) of the cooling water cooler (3), and the circulating water return (26) is connected to the pipe-side water return L2 (28) of the cooling water cooler (3).

5. The carbon dioxide capture compressor interstage waste heat refrigeration energy-saving device according to claim 4, characterized in that: The circulating water supply (25) is provided with a supply branch pipe (29), and the circulating water return (26) is provided with a return branch pipe (30). The supply branch pipe (29) is connected to the absorption type waste heat refrigeration machine (1), passes through the absorber (9) and the condenser (11) in sequence, and then flows back to the circulating water return (26) from the return branch pipe (30).

6. The carbon dioxide capture compressor interstage waste heat refrigeration energy-saving device according to claim 3, characterized in that: A waste heat water pump (31) is provided on the first circulating water return (14) pipeline; and a refrigerant water pump (32) is provided on the second circulating water supply (19) pipeline.

7. The carbon dioxide capture compressor interstage waste heat refrigeration energy-saving device according to claim 6, characterized in that: A temperature-controlled three-way valve (33) is provided on the first circulating water supply (13) pipeline, a branch (34) of the temperature-controlled three-way valve (33) is connected to the inlet pipe (35) of the waste heat water pump (31), a first cross-line pipe (36) is provided at the front end of the temperature-controlled three-way valve (33), the other end of the first cross-line pipe (36) is connected to the inlet pipe (35), a second cross-line pipe (37) is provided on the temperature-controlled three-way valve (33), and both ends of the second cross-line pipe (37) are respectively connected to the front and rear ends of the temperature-controlled three-way valve (33).

8. A compressor interstage waste heat refrigeration energy-saving device for carbon dioxide capture according to claim 6 or 7, characterized in that: The front ends of the waste heat water pump (31) and the refrigerant water pump (32) are both provided with water supply pipelines (38).

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