A compressed tail gas energy storage power generation system with synergistic tail gas dehydration treatment and application thereof

Abstract

The application discloses a compressed tail gas energy storage power generation system with synergistic tail gas dehydration treatment and application thereof. The system comprises a tail gas compression and conveying unit, a tail gas compression injection and extraction unit, an output gas condensation and dehydration unit and a multi-stage expansion power generation unit connected in sequence; the output gas condensation and dehydration unit comprises a first condensation and dehydration device and a second condensation and dehydration device; the multi-stage expansion power generation unit comprises a first expansion power generation device and a second expansion power generation device; a heat source inlet of the first condensation and dehydration device is connected with the tail gas compression injection and extraction unit, and a heat source outlet is connected with a heat source inlet of the second condensation and dehydration device; a cold source inlet of the first condensation and dehydration device is connected with the first expansion power generation device, and a cold source outlet is connected with the second expansion power generation device; a heat source outlet of the second condensation and dehydration device is connected with the first expansion power generation device, and a cold source inlet is connected with the second expansion power generation device. The system realizes the cyclic utilization of cold and heat energy, and improves the energy conversion rate and energy utilization rate.

Description

Technical Field

[0001] This invention relates to the field of compressed gas energy storage and power generation technology, and in particular to a compressed gas energy storage and power generation system with synergistic exhaust gas dehydration treatment and its application. Background Technology

[0002] As the world's third-largest stationary source of greenhouse gas emissions, the oil refining industry is projected to emit as much as 16.5 Gt of carbon dioxide (CO2) between 2020 and 2030. Strengthening energy conservation, emission reduction, and green, low-carbon transformation in the energy sector has become an inevitable choice for achieving sustainable development.

[0003] Carbon capture, utilization, and storage (CCUS) technology, which purifies CO2 emitted during production processes and then recycles or stores it in new production processes, is a crucial technological solution for achieving emission reduction targets. However, the high energy consumption, high cost, and high uncertainty of CCUS technology restrict its large-scale engineering application. How to reduce CO2 capture costs and how to increase economic benefits through the effective utilization of greenhouse gases are key challenges that must be addressed to effectively apply CCUS technology to achieve energy conservation and emission reduction goals. To address this issue, current research and field trials have shown that directly storing exhaust gases or injecting treated CO2 containing a certain proportion of impurities such as sulfur dioxide and nitrogen oxides into the formation can effectively reduce engineering implementation costs. Furthermore, the injection of impurity gases such as sulfur dioxide and nitrogen oxides can accelerate the dissolution reaction of minerals in saline aquifers, thus accelerating the sequestration of CO2 minerals in saline aquifers.

[0004] In terms of energy utilization, storing highly volatile renewable energy sources through compressed gas energy storage technology and converting them into energy through gas expansion power generation helps optimize the energy structure, achieve energy conservation, emission reduction, and scientific energy use, and has extremely high development prospects. Summary of the Invention

[0005] To enrich the types of exhaust gas power generation systems and increase the options for exhaust gas dehydration treatment and exhaust gas energy storage power generation, this invention proposes a compressed exhaust gas energy storage power generation system that combines exhaust gas dehydration treatment with its application.

[0006] In a first aspect, embodiments of the present invention provide a compressed tail gas energy storage and power generation system for synergistic tail gas dehydration treatment, comprising a tail gas compression and conveying unit, a tail gas compression injection and extraction unit, a product gas condensation and dehydration unit, and a multi-stage expansion power generation unit connected in sequence.

[0007] The exhaust gas compression and delivery unit is adapted to compress the exhaust gas and deliver it to the exhaust gas compression injection and extraction unit.

[0008] The tail gas compression injection and collection unit is adapted to pressurize and store the tail gas, and to pass the stored tail gas as high-pressure output gas into the output gas condensation and dehydration unit.

[0009] The output gas condensation and dehydration unit includes a first condensation and dehydration device and a second condensation and dehydration device;

[0010] The multi-stage expansion power generation unit includes a first expansion power generation device and a second expansion power generation device.

[0011] The heat source inlet of the first condensation and dehydration device is connected to the tail gas compression injection and extraction unit, and the heat source outlet is connected to the heat source inlet of the second condensation and dehydration device.

[0012] The cold source inlet of the first condensation dehydration device is connected to the first expansion power generation device, and the cold source outlet is connected to the second expansion power generation device;

[0013] The heat source outlet of the second condensation dehydration device is connected to the first expansion power generation device, and the cold source inlet is connected to the second expansion power generation device.

[0014] In one or more alternative embodiments, the first condensation and dehydration device includes a first heat exchanger and a first separator;

[0015] The heat source inlet of the first heat exchanger is connected to the exhaust gas compression injection and sampling unit, and the first separator is connected between the heat source outlet of the first heat exchanger and the heat source inlet of the second condensation and dehydration device.

[0016] The cold source inlet of the first heat exchanger is connected to the first expansion power generation device, and the cold source outlet is connected to the second expansion power generation device.

[0017] In one or more alternative embodiments, the second condensation dehydration device includes a second heat exchanger and a second separator;

[0018] The heat source inlet of the second heat exchanger is connected to the first separator, and the second separator is connected between the heat source outlet of the second heat exchanger and the first expansion power generation device;

[0019] The cold source inlet of the second heat exchanger is connected to the second expansion power generation device.

[0020] In one or more alternative embodiments, the first expansion power generation device includes a first heater and a first turbine generator connected together;

[0021] The first heater is connected to the second separator;

[0022] The first turbine generator is connected to the cold source inlet of the first heat exchanger.

[0023] In one or more alternative embodiments, the second expansion power generation device includes a connected second heater and a second turbine generator;

[0024] The second heater is connected to the cold source outlet of the first heat exchanger;

[0025] The second turbine generator is connected to the cold source inlet of the second heat exchanger.

[0026] In one or more alternative embodiments, the second expansion power generation device further includes a third heater and a third turbine generator connected between the second turbine generator and the cold source inlet of the second heat exchanger.

[0027] In one or more alternative embodiments, the second expansion power generation device further includes a fourth heater and a fourth turbine generator connected between the third turbine generator and the cold source inlet of the second heat exchanger.

[0028] In one or more alternative embodiments, the first heater, the second heater, the third heater, and the fourth heater are solar heaters.

[0029] In one or more alternative embodiments, the first heat exchanger is connected to the storage space.

[0030] In one or more alternative embodiments, the exhaust gas compression and delivery unit includes a connected exhaust gas treatment device and a first compressor.

[0031] In one or more alternative embodiments, the exhaust gas compression injection and extraction unit includes a second compressor connected to the storage space;

[0032] The first compressor is connected to the second compressor.

[0033] Secondly, embodiments of the present invention provide an application of the compressed exhaust gas energy storage and power generation system described in the first aspect, which involves synergistic exhaust gas dehydration treatment in exhaust gas dehydration treatment and compressed exhaust gas energy storage and power generation.

[0034] The beneficial effects of the above-mentioned technical solutions provided in the embodiments of the present invention include at least the following:

[0035] The compressed exhaust gas energy storage and power generation system provided in this embodiment of the invention connects the heat source inlet of the first condensation and dehydration device to the exhaust gas compression injection and extraction unit, and connects the cold source inlet of the first condensation and dehydration device to the first expansion power generation device. This allows for heat exchange between the heat energy of the high-pressure output gas from the exhaust gas compression injection and extraction unit and the cold energy of the expanded gas in the first expansion power generation device. This achieves initial condensation and dehydration of the high-pressure output gas and heating of the expanded gas, thereby realizing the recycling of heat and cold energy within the system and improving the system's energy conversion rate. Connecting the cold source outlet of the first condensation and dehydration device to the second expansion power generation device allows the expanded gas from the first expansion power generation device to be heated before entering the second expansion power generation device, reducing the energy consumption of the second expansion power generation device. Connecting the cold source inlet of the second condensation and dehydration device to the second expansion power generation device utilizes the cold energy of the expanded gas in the second expansion power generation device to cool the high-pressure output gas in the second condensation and dehydration device, realizing the utilization of cold energy within the system and improving the system's energy utilization rate.

[0036] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0037] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0038] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0039] Figure 1 This is a schematic diagram of the structure of the compressed exhaust gas energy storage and power generation system provided in the embodiment of the present invention for synergistic exhaust gas dehydration treatment.

[0040] In the picture:

[0041] 100 is the exhaust gas compression and conveying unit, 200 is the exhaust gas compression injection and extraction unit, 300 is the produced gas condensation and dehydration unit, and 400 is the multi-stage expansion power generation unit.

[0042] 1 is the exhaust gas treatment device, 2 is the first compressor, 3 is the conveying device, 4 is the second compressor, 5 is the exhaust gas injection well, 6 is the storage space, 7 is the high-pressure gas production well, 8 is the first heat exchanger, 9 is the first separator, 10 is the second heat exchanger, 11 is the second separator, 12 is the first heater, 13 is the first turbine generator, 14 is the second heater, 15 is the second turbine generator, 16 is the third heater, 17 is the third turbine generator, 18 is the fourth heater, and 19 is the fourth turbine generator. Detailed Implementation

[0043] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0044] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," "far," "near," "front," and "rear," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0045] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0046] The inventors discovered that storing highly volatile renewable energy sources using compressed gas energy storage technology and converting them into electricity through gas expansion can help achieve energy conservation, emission reduction, and scientific energy use. The energy conversion efficiency of existing commercially operational compressed gas energy storage power generation systems is only 40%–50%. Large quantities of CO2-containing industrial waste gas can be compressed and used for gas expansion power generation. However, storing and utilizing this waste gas requires pressurization, transportation, condensation and dehydration of the produced gas, and heating of the low-temperature gas to compensate for the significant cooling caused by adiabatic expansion. All of these factors further reduce the overall energy conversion rate.

[0047] Therefore, there is an urgent need to optimize compressed air exhaust gas energy storage and power generation systems to reduce energy loss and achieve more efficient industrial exhaust gas storage and utilization, thus contributing to energy transition. Based on this, the present invention provides a compressed air exhaust gas energy storage and power generation system with synergistic exhaust gas dehydration treatment and its application, which will be described in detail below through specific embodiments.

[0048] Example 1

[0049] This invention provides a compressed exhaust gas energy storage and power generation system that coordinates exhaust gas dehydration treatment, referring to... Figure 1 As shown, it includes a tail gas compression and conveying unit 100, a tail gas compression and injection unit 200, a produced gas condensation and dehydration unit 300, and a multi-stage expansion power generation unit 400 connected in sequence.

[0050] The exhaust gas compression and delivery unit 100 is adapted to compress the exhaust gas and deliver it to the exhaust gas compression injection and extraction unit 200.

[0051] The exhaust gas compression injection and extraction unit 200 is adapted to pressurize and store the exhaust gas, and to pass the stored exhaust gas as high-pressure output gas into the output gas condensation and dehydration unit 300.

[0052] The output gas condensation and dehydration unit 300 includes a first condensation and dehydration device and a second condensation and dehydration device;

[0053] The multi-stage expansion power generation unit 400 includes a first expansion power generation device and a second expansion power generation device.

[0054] The heat source inlet of the first condensation and dehydration device is connected to the tail gas compression injection and extraction unit 200, and the heat source outlet is connected to the heat source inlet of the second condensation and dehydration device.

[0055] The cold source inlet of the first condensation and dehydration device is connected to the first expansion power generation device, and the cold source outlet is connected to the second expansion power generation device.

[0056] The heat source outlet of the second condensation and dehydration device is connected to the first expansion power generation device, and the cold source inlet is connected to the second expansion power generation device.

[0057] The compressed tail gas energy storage and power generation system provided in this embodiment of the invention can compress and store large amounts of CO2-containing industrial tail gas for expansion power generation. The industrial tail gas undergoes a first compression in the tail gas compression and conveying unit 100. The tail gas after the first compression enters the tail gas compression injection and extraction unit 200 for a second compression and storage. The stored high-pressure gas is extracted to obtain high-pressure output gas. The high-pressure output gas is then fed into the output gas condensation and dehydration unit 300, undergoing two condensation and dehydration treatments in sequence through a first condensation and dehydration device and a second condensation and dehydration device. Afterward, it is fed into a multi-stage expansion power generation unit 400, undergoing expansion power generation in sequence through a first expansion power generation device and a second expansion power generation device. The expanded gas from the first expansion power generation device is sent to the first condensation and dehydration device, where it exchanges heat with the high-pressure output gas and is heated before being fed into the second expansion power generation device. The expanded gas from the second expansion power generation device is then sent to the second condensation and dehydration device, where it exchanges heat with the high-pressure output gas.

[0058] In this embodiment of the invention, the expanded gas from the first expansion power generation device is used as the refrigerant in the first condensation and dehydration device to cool the high-pressure output gas in the first condensation and dehydration device. This not only achieves the purpose of primary condensation and dehydration of the high-pressure output gas, but also raises the temperature of the expanded gas from the first expansion power generation device before it enters the second expansion power generation device, reducing the energy consumption of the second expansion power generation device, realizing the recycling of cold and heat energy within the system, and improving the system's energy conversion rate. The expanded gas from the second expansion power generation device is used as the refrigerant in the second condensation and dehydration device to cool the high-pressure output gas in the second condensation and dehydration device, achieving the purpose of secondary condensation and dehydration of the high-pressure output gas, realizing the utilization of cold energy within the system, and improving the system's energy utilization rate.

[0059] In one specific embodiment, reference is made to Figure 1 As shown, the exhaust gas compression and transportation unit 100 includes an exhaust gas treatment device 1, a first compressor 2, and a transportation device 3 connected in sequence. The first compressor 2 and the transportation device 3 are connected via pipeline S02. In the exhaust gas compression and transportation unit 100, industrial exhaust gas first enters the exhaust gas treatment device 1 for pretreatment such as dehydration and dust removal, and then enters the first compressor 2 for pressurization before being transported to the exhaust gas compression and injection unit 200 via the transportation device 3. The first compressor 2 needs to perform multi-stage compression on the industrial exhaust gas after dust removal and dehydration treatment, raising the exhaust gas from near atmospheric pressure to a preset pressure level.

[0060] In one specific embodiment, reference is made to Figure 1As shown, the exhaust gas compression injection and production unit 200 is located near the storage space 6 and includes a second compressor 4 connected to the storage space 6. The second compressor 4 is connected to the storage space 6 via an exhaust gas injection well 5 and is also connected to the aforementioned conveying device 3. The storage space 6 is connected to a high-pressure gas production well 7, through which high-pressure gas can be extracted from the storage space 6 to obtain high-pressure produced gas. The conveying device 3 is connected to the second compressor 4 via pipeline S03, the second compressor 4 is connected to the exhaust gas injection well 5 via pipeline S04, and the exhaust gas injection well 5 is connected to the storage space 6 via pipeline S05. In the exhaust gas compression injection and production unit 200, the industrial exhaust gas from the conveying device 3 is pressurized a second time by the second compressor 4 at the wellhead of the exhaust gas injection well 5 and then introduced into the exhaust gas injection well 5, and then injected into the saline aquifer storage space for storage via the exhaust gas injection well 5; when it is necessary to extract the stored high-pressure gas, high-pressure produced gas is extracted through the high-pressure gas production well 7.

[0061] In one specific embodiment, the storage space 6 can be an underground structure such as a saline aquifer storage space or a karst cave, and can be selected and set according to the actual environmental conditions. Here, no limitation is made.

[0062] In this embodiment of the invention, the tail gas injection well 5 and the high-pressure gas production well 7 can be two different wells or the same well, but due to the limitations of the actual environment, they are usually the same well. Since the injection of high-pressure tail gas into the storage space 6 causes the pressure inside the storage space 6 to rise, and the maximum pressure inside the storage space 6 cannot exceed the rock fracture pressure, when the tail gas injection well 5 and the high-pressure gas production well 7 are the same well, the stored high-pressure gas is first injected into the storage space 6 at a certain pressure through this well and then shut off. After sufficient contact and reaction with the formation water, rock minerals, etc., in the storage space 6 for a certain period of time, the well is then opened to produce high-pressure produced gas. When the tail gas injection well 5 and the high-pressure gas production well 7 are two different wells, the timing of opening and closing the wells is adjusted according to the pressure monitoring data of the storage space 6. When the pressure inside the storage space 6 is too high, it is necessary to stop the injection and shut off the well, or to start extracting the stored high-pressure gas.

[0063] In this embodiment of the invention, due to the gas dissolution, migration, and mineral reactions that occur in the storage space 6, the high-pressure produced gas extracted from the high-pressure gas production well 7 contains CO2, SO2, and NO. x The composition of the high-pressure produced gas is different from that of the tail gas injected from tail gas injection well 5, which causes a certain change in the volume of the extracted high-pressure produced gas. The partial pressure of H2O in the high-pressure produced gas produced from high-pressure gas production well 7 is its saturated vapor pressure.

[0064] In one specific embodiment, reference is made to Figure 1As shown, the product gas condensation and dehydration unit 300 includes a first condensation and dehydration device and a second condensation and dehydration device connected together. The first condensation and dehydration device includes a first heat exchanger 8 and a first separator 9, and the second condensation and dehydration device includes a second heat exchanger 10 and a second separator 11. The heat source inlet of the first heat exchanger 8 is connected to the high-pressure gas production well 7, and the heat source outlet is connected to the first separator 9. The heat source inlet of the second heat exchanger 10 is connected to the first separator 9, and the heat source outlet is connected to the second separator 11. The first heat exchanger 8 is connected to the high-pressure gas production well 7 through pipeline S07 and to the first separator 9 through pipeline S08. The first separator 9 is connected to the second heat exchanger 10 through pipeline S09, and the second heat exchanger 10 is connected to the second separator 11 through pipeline S10. In the condensation and dehydration unit 300, the high-pressure output gas is cooled by the first heat exchanger 8 and then enters the first separator 9 to complete the initial condensation and dehydration. After passing through the second heat exchanger 10 to be cooled to the preset temperature, it enters the second separator 11 for condensation and dehydration again, so that the dryness of the high-pressure output gas meets the requirements of expansion power generation.

[0065] In one specific embodiment, reference is made to Figure 1As shown, the multi-stage expansion power generation unit 400 includes a first expansion power generation device and a second expansion power generation device; the first expansion power generation device includes a first heater 12 and a first turbine generator 13 connected together; the second expansion generator includes a second heater 14, a second turbine generator 15, a third heater 16, a third turbine generator 17, a fourth heater 18, and a fourth turbine generator 19 connected in sequence; the first turbine generator 13 is connected to a first heat exchanger 8, the first heat exchanger 8 is connected to the second heater 14, the first heater 12 is connected to the aforementioned second separator 11; and the fourth turbine generator 19 is connected to the second heat exchanger 10. The first heater 12 is connected to the second separator 11 via pipeline S11 and to the first turbine generator 13 via pipeline S12; the first turbine generator 13 is connected to the first heat exchanger 8 via pipeline S13; the first heat exchanger 8 is connected to the second heater 14 via pipeline S14; the second heater 14 is connected to the second turbine generator 15 via pipeline S15; the second turbine generator 15 is connected to the third heater 16 via pipeline S16; the third heater 16 is connected to the third turbine generator 17 via pipeline S17; the third turbine generator 17 is connected to the fourth heater 18 via pipeline S18; the fourth heater 18 is connected to the fourth turbine generator 19 via pipeline S19; and the fourth turbine generator 19 is connected to the second heat exchanger 10 via pipeline S20. In the multi-stage expansion power generation unit 400, the high-pressure output gas after condensation and dehydration is first heated to a preset temperature by the first heater 12, and then enters the first turbine generator 13 to use its internal energy for first-stage expansion power generation. Subsequently, it is heated to a preset temperature by the second heater and then enters the second turbine generator 15 for second-stage expansion power generation. After being heated to a preset temperature by the third heater 16, it enters the third turbine generator 17 for third-stage expansion power generation. Finally, it is heated to a preset temperature by the fourth heater 18 and then enters the fourth turbine generator 19 for fourth-stage expansion power generation.

[0066] In this embodiment of the invention, the cold source inlet of the first heat exchanger 8 is connected to the first turbine generator 13, and the cold source outlet is connected to the second heater 14; the cold source inlet of the second heat exchanger 10 is connected to the fourth turbine generator 19. After the high-pressure produced gas undergoes expansion and power generation at each stage, the pressure gradually decreases, and the temperature also decreases due to gas expansion. Using the high-pressure produced gas with residual heat from the high-pressure gas production well as the refrigerant of the first heat exchanger 8, and the first-stage expanded gas flowing out of the first turbine generator 13 as the heat medium of the first heat exchanger 8, heat exchange occurs within the first heat exchanger 8, completing the heating of the first-stage expanded gas and the initial cooling and condensation of the high-pressure produced gas. Simultaneously, the waste heat of the high-pressure produced gas and the cold energy of the first-stage expanded gas are utilized, thereby achieving the recycling of cold and heat energy within the system and improving the system's energy conversion rate. The high-pressure output gas after initial condensation and dehydration is used as the heat medium of the second heat exchanger 10, and the gas after fourth-stage expansion flowing out of the fourth turbine generator 19 is used as the cold medium of the second heat exchanger 10. The gas flows in the second heat exchanger 10 to complete the secondary cooling and condensation of the high-pressure output gas, thereby realizing the utilization of the cold energy of the gas after fourth-stage expansion, realizing the utilization of cold energy in the system, and improving the system energy utilization rate.

[0067] Furthermore, to improve heat exchange efficiency and further reduce energy consumption, the temperature rise of the first heater 12 and / or the pressure ratio of the first turbine generator 13 can be reduced so that the temperature of the first-stage expanded gas flowing out of the first turbine generator 13 is lower than the high-pressure output gas with residual heat flowing through the first heat exchanger 8, creating a larger temperature difference between the two. Similarly, the temperature rise of the fourth heater 18 and / or the pressure ratio of the fourth turbine generator 19 can be reduced so that the temperature of the fourth-stage expanded gas flowing out of the fourth turbine generator 19 is lower than the high-pressure output gas with residual heat flowing through the second heat exchanger 10, creating a larger temperature difference between the two. Additionally, the temperature rise of the second heater 14 and / or the pressure ratio of the second turbine generator 15, as well as the temperature rise of the third heater 16 and / or the pressure ratio of the third turbine generator 17, can be reduced so that the temperatures of the second-stage expanded gas from the second turbine generator 15 and the tertiary expanded gas from the third turbine generator 17 do not exceed the temperature required for the high-pressure output gas to undergo condensation and dehydration treatment in the second heat exchanger 10.

[0068] In this embodiment of the invention, the pressure ratio of the first turbine generator 13, the second turbine generator 15, and the third turbine generator 17 should not be too high to prevent excessive single-stage expansion. Specifically, it can be reasonably set according to actual needs, for example, it can be 0.3. The fourth turbine generator 19 is used for the final stage of expansion power generation, and its pressure ratio can be slightly higher than that of the first turbine generator 13, the second turbine generator 15, and the third turbine generator 17, for example, it can be 0.4. By using the multi-stage expansion power generation unit 400 to heat the high-pressure output gas multiple times and perform multi-stage expansion power generation, and by reasonably setting the pressure ratio of the first turbine generator 13, the second turbine generator 15, the third turbine generator 17, and the fourth turbine generator 19, the temperature drop to the dew point or even the freezing point caused by excessive single-stage expansion is avoided.

[0069] In this embodiment of the invention, the gas discharged from the fourth turbine generator 19 after four-stage expansion is already atmospheric pressure exhaust gas. After the gas after four-stage expansion provides cooling energy to the second heat exchanger 10, it can be recompressed by the second compressor 4 and injected into the exhaust gas injection well 5 when there is surplus power, or it can be treated and discharged.

[0070] In this embodiment of the invention, the first heater 12, the second heater 14, the third heater 16, and the fourth heater 18 can be solar power generators, utilizing solar energy to heat the high-pressure output gas, which is more environmentally friendly. Obviously, the first heater 12, the second heater 14, the third heater 16, and the fourth heater 18 can also provide heat by converting other renewable energy sources into electricity, for example, wind power heating.

[0071] The compressed exhaust gas energy storage and power generation system provided in this embodiment of the invention reduces energy consumption and improves the overall energy conversion rate and energy utilization rate of the system by coupling renewable energy sources such as solar energy and internal cold and heat energy.

[0072] The compressed exhaust gas energy storage and power generation system provided in this embodiment of the invention can use surplus electricity to compress industrial exhaust gas during off-peak hours and store the compressed exhaust gas in storage space 6. During peak hours, the stored high-pressure exhaust gas is expanded to generate electricity. This not only enables the use of energy storage space 6, but also enables the sequestration of a large amount of carbon in a short period of time.

[0073] To more clearly illustrate the specific implementation process of the embodiments of the present invention, the following embodiments are provided for further detailed description of the present invention:

[0074] This embodiment uses Aspen Plus to simulate the working process of a compressed exhaust gas energy storage and power generation system that performs synergistic exhaust gas dehydration treatment.

[0075] In the exhaust gas compression and transportation unit 100, industrial exhaust gas enters the exhaust gas treatment device 1 for dust removal and dehydration treatment. Then, it is pressurized to 5 MPa by the first compressor 2 and transported via the transportation device 3 to the exhaust gas compression injection and collection unit 200 for compression, energy storage, and sealing. The transportation distance is 100 km. The components of the industrial exhaust gas include CO2, H2O, N2, O2, SO2, and NO. x The mole fractions of each component are shown in Table 1.

[0076] Table 1 Composition of Industrial Exhaust Gas

[0077] Components mole fraction % <![CDATA[CO2]]> 13 <![CDATA[H2O]]> 6 <![CDATA[N2]]> 75 <![CDATA[O2]]> 5 <![CDATA[SO2]]> 0.86 <![CDATA[NO x ]]> 0.14

[0078] In the tail gas compression injection and production unit 200, the industrial tail gas from the conveying device 3 is further pressurized to 21 MPa by the second compressor 4 at the wellhead of the tail gas injection well 5, and then introduced into the tail gas injection well 5. It is then injected into the saline aquifer storage space for storage. In this embodiment, the temperature of the saline aquifer storage space is 80°C and the pressure is 30 MPa. When it is necessary to extract the stored high-pressure gas, the high-pressure gas production well 7 extracts high-pressure produced gas with a pressure of 29 MPa. To make this embodiment more obvious and easy to understand, the heat loss of the wellbore is ignored here.

[0079] In the output gas condensation and dehydration unit 300, the high-pressure output gas flows through the first condensation and dehydration device for initial condensation and dehydration, and then flows through the second condensation and dehydration device for further condensation and dehydration.

[0080] After undergoing two condensation and dehydration processes, the high-pressure output gas enters the multi-stage expansion power generation unit 400. First, it is heated to 120°C by the first heater 12 and then enters the first turbine generator 13 (pressure ratio 0.3) for first-stage expansion power generation. Subsequently, it is heated to 120°C by the second heater 14 and then enters the second turbine generator 15 (pressure ratio 0.3) for second-stage expansion power generation. Next, it is heated to 120°C by the third heater 16 and then enters the third turbine generator 17 (pressure ratio 0.3) for third-stage expansion power generation. Finally, it is heated to 120°C by the fourth heater 18 and then enters the fourth turbine generator 19 (turbine exhaust total pressure is 0.101MPa) for fourth-stage expansion power generation.

[0081] This invention simulates three different schemes: Scheme 1, Scheme 2, and Scheme 3. Scheme 1 presents the simulation results of a compressed gas energy storage and power generation system utilizing synergistic exhaust gas dehydration treatment; the heat exchanger simulation results for this scheme are shown in Table 2. Scheme 2 presents the simulation results of high-pressure output gas condensation and dehydration via external power supply; the energy consumption method for heating the high-pressure output gas in this scheme is consistent with Scheme 1. Scheme 3 presents the simulation results of high-pressure output gas condensation, dehydration, and heating via external power supply. The load and total system energy conversion efficiency results for each scheme are shown in Table 3. The final total system energy conversion efficiency for Schemes 1, 2, and 3 are 43%, 39%, and 28%, respectively.

[0082] It should be noted that all the above schemes take into account the energy consumption of gas transportation. When the energy consumption of gas transportation is not considered, the total energy conversion rate of the system calculated by Scheme 3 is approximately 46%, which is within the energy conversion efficiency range of currently commercially operating compressed gas energy storage power stations, thus proving the rationality of the model. Under the same conditions, according to the assumptions and parameter values ​​of the embodiments of the present invention, the high-efficiency energy-saving system proposed in this patent can increase the total energy conversion rate of the compressed gas power generation system by 53%.

[0083] Table 2. Simulation Calculation Results of Heat Exchanger

[0084] Table 3 shows the load and total system energy conversion efficiency results for each scheme.

[0085]

[0086]

[0087] Example 2

[0088] Based on the same inventive concept, embodiments of the present invention also provide a method for energy storage and power generation of compressed exhaust gas with synergistic exhaust gas dehydration treatment, comprising:

[0089] The exhaust gas is compressed by the exhaust gas compression and delivery unit 100.

[0090] The exhaust gas is further compressed and stored underground through the exhaust gas compression and injection unit 200, and the stored high-pressure gas is extracted to obtain high-pressure output gas.

[0091] The heat energy of the high-pressure produced gas is transferred through the condensation and dehydration unit 300 to the cold energy of the expanded gas in the multi-stage expansion power generation unit 400.

[0092] The cold energy of the gas after expansion by the multi-stage expansion power generation unit 400 is used to condense the high-pressure output gas.

[0093] The high-pressure output gas is expanded and generated by the multi-stage expansion power generation unit 400.

[0094] In this embodiment of the invention, the compressed tail gas energy storage and power generation method for synergistic tail gas dehydration treatment can refer to the process of compressed tail gas energy storage and power generation for tail gas dehydration treatment in Embodiment 1 above. The repeated parts will not be described again here.

[0095] Example 3

[0096] Based on the same inventive concept, this invention also provides an application of a compressed exhaust gas energy storage and power generation system that combines exhaust gas dehydration treatment with compressed exhaust gas energy storage and power generation.

[0097] In this embodiment of the invention, the application of the compressed tail gas energy storage power generation system with synergistic tail gas dehydration treatment in tail gas dehydration treatment and compressed tail gas energy storage power generation can refer to the process of compressed tail gas energy storage power generation with synergistic tail gas dehydration treatment in Embodiment 1 above. The repeated parts will not be described again here.

[0098] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. This disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims. Thus, if these modifications and variations of the invention fall within the scope of the claims of the invention and their equivalents, the invention is also intended to include these modifications and variations.

Claims

1. A compressed exhaust gas energy storage and power generation system with synergistic exhaust gas dehydration treatment, characterized in that, It includes a tail gas compression and conveying unit, a tail gas compression and injection unit, a product gas condensation and dehydration unit, and a multi-stage expansion power generation unit connected in sequence. The exhaust gas compression and delivery unit is adapted to compress the exhaust gas and deliver it to the exhaust gas compression injection and extraction unit. The tail gas compression injection and collection unit is adapted to pressurize the tail gas and store it in a storage space, and to pass the high-pressure produced gas from the storage space into the produced gas condensation and dehydration unit. The output gas condensation and dehydration unit includes a first condensation and dehydration device and a second condensation and dehydration device; The multi-stage expansion power generation unit includes a first expansion power generation device and a second expansion power generation device. The heat source inlet of the first condensation and dehydration device is connected to the tail gas compression injection and extraction unit, and the heat source outlet is connected to the heat source inlet of the second condensation and dehydration device. The cold source inlet of the first condensation dehydration device is connected to the first expansion power generation device, and the cold source outlet is connected to the second expansion power generation device; The heat source outlet of the second condensation and dehydration device is connected to the first expansion power generation device, and the cold source inlet is connected to the second expansion power generation device; The exhaust gas compression and delivery unit includes a connected exhaust gas treatment device and a first compressor; The exhaust gas compression injection and extraction unit includes a second compressor connected to the storage space; The first compressor is connected to the second compressor; The heat source of the first condensation and dehydration device is the high-pressure output gas from the tail gas compression injection and extraction unit, and the cold source is the expansion gas discharged from the first expansion power generation device; the heat source of the second condensation and dehydration device is the gas output from the first condensation and dehydration device, and the cold source is the expansion gas discharged from the second expansion power generation device; the expansion gas discharged from the second expansion power generation device can be recompressed and stored by the second compressor when there is a power surplus after providing cold energy to the second condensation and dehydration device.

2. The compressed exhaust gas energy storage and power generation system for synergistic exhaust gas dehydration treatment according to claim 1, characterized in that, The first condensation and dehydration device includes a first heat exchanger and a first separator; The heat source inlet of the first heat exchanger is connected to the exhaust gas compression injection and sampling unit, and the first separator is connected between the heat source outlet of the first heat exchanger and the heat source inlet of the second condensation and dehydration device. The cold source inlet of the first heat exchanger is connected to the first expansion power generation device, and the cold source outlet is connected to the second expansion power generation device.

3. The compressed exhaust gas energy storage and power generation system for synergistic exhaust gas dehydration treatment according to claim 2, characterized in that, The second condensation and dehydration device includes a second heat exchanger and a second separator; The heat source inlet of the second heat exchanger is connected to the first separator, and the second separator is connected between the heat source outlet of the second heat exchanger and the first expansion power generation device; The cold source inlet of the second heat exchanger is connected to the second expansion power generation device.

4. The compressed exhaust gas energy storage and power generation system for synergistic exhaust gas dehydration treatment according to claim 3, characterized in that, The first expansion power generation device includes a first heater and a first turbine generator connected together; The first heater is connected to the second separator; The first turbine generator is connected to the cold source inlet of the first heat exchanger.

5. The compressed exhaust gas energy storage and power generation system for synergistic exhaust gas dehydration treatment according to claim 4, characterized in that, The second expansion power generation device includes a second heater and a second turbine generator connected together; The second heater is connected to the cold source outlet of the first heat exchanger; The second turbine generator is connected to the cold source inlet of the second heat exchanger.

6. The compressed exhaust gas energy storage and power generation system for synergistic exhaust gas dehydration treatment according to claim 5, characterized in that, The second expansion power generation device also includes a third heater and a third turbine generator connected between the second turbine generator and the cold source inlet of the second heat exchanger.

7. The compressed exhaust gas energy storage and power generation system for synergistic exhaust gas dehydration treatment according to claim 6, characterized in that, The second expansion power generation device also includes a fourth heater and a fourth turbine generator connected between the third turbine generator and the cold source inlet of the second heat exchanger.

8. The compressed exhaust gas energy storage and power generation system for synergistic exhaust gas dehydration treatment according to claim 7, characterized in that, The first heater, the second heater, the third heater, and the fourth heater are solar heaters.

9. The compressed exhaust gas energy storage and power generation system for synergistic exhaust gas dehydration treatment according to claim 2, characterized in that, The first heat exchanger is connected to the storage space.

10. The application of the compressed exhaust gas energy storage and power generation system according to any one of claims 1-9 in exhaust gas dehydration treatment and compressed exhaust gas energy storage and power generation.

Images