Supercritical carbon dioxide cycle power generation system

Abstract

The utility model discloses a supercritical carbon dioxide cycle power generation system which comprises a pressure containing tank for storing supercritical carbon dioxide, a generator, a gas compressor, a heat regenerator, a first heat exchanger, an internal combustion engine, a turbine and a rotating shaft, the pressure containing tank is connected with the gas compressor, the gas compressor is connected with the heat regenerator, the heat regenerator is connected with the first heat exchanger, and the first heat exchanger is connected with the turbine. The first heat exchanger is connected with the internal combustion engine, the first heat exchanger is connected with the turbine, the turbine, the generator and the gas compressor are all fixed to the rotating shaft, the turbine is further connected with the heat regenerator, and the heat regenerator is connected with the pressure containing tank. The supercritical carbon dioxide power generation device can generate power by using supercritical carbon dioxide.

Description

Technical Field

[0001] The utility model relates to a supercritical carbon dioxide cycle power generation system. Background Art

[0002] At present, most of the waste heat utilization schemes use waste heat to heat water to generate steam for power generation. However, due to the physical property characteristics of water phase change during the circulation process and the limitations of material development, the improvement of the efficiency of the Rankine cycle with water as the working fluid has almost reached a bottleneck. Therefore, an energy cycle based on a new working fluid is urgently needed to be developed.

[0003] At present, supercritical carbon dioxide is considered to be the most potential energy cycle working fluid in the future due to its easy availability in the supercritical state, large energy density, stable properties, non-toxic and non-corrosive, simple system and compact structure. The research on supercritical carbon dioxide power generation has gradually attracted the attention of scholars.

[0004] In the currently publicly disclosed patent achievements at home and abroad, the content regarding the utilization of industrial waste heat by supercritical carbon dioxide is relatively scarce. The existing patents either hardly consider the problem of energy cascade utilization, or integrate other cycles, resulting in the system being too complex and losing the advantages of the supercritical carbon dioxide power generation system, or do not consider the heat source level of the waste heat, resulting in the existing system being no longer applicable when the heat source temperature changes greatly, etc. Summary of the Utility Model

[0005] The utility model provides a supercritical carbon dioxide cycle power generation system, which can utilize supercritical carbon dioxide for power generation.

[0006] The technical solution for solving the above technical problems is as follows:

[0007] The supercritical carbon dioxide cycle power generation system includes a pressure vessel for storing supercritical carbon dioxide, a generator, and also includes a compressor, a recuperator, a first heat exchanger, an internal combustion engine, a turbine, and a rotating shaft. The pressure vessel is connected to the compressor, the compressor is connected to the recuperator, the recuperator is connected to the first heat exchanger, the first heat exchanger is connected to the internal combustion engine, the first heat exchanger is connected to the turbine, the turbine, the generator, and the compressor are all fixed to the rotating shaft, the turbine is also connected to the recuperator, and the recuperator is connected to the pressure vessel.

[0008] Supercritical carbon dioxide power generation system, including a pressure vessel for storing supercritical carbon dioxide, a generator, and also including a compressor, a recuperator, a first heat exchanger, an internal combustion engine, a turbine, a rotating shaft, and a third heat exchanger. The pressure vessel is connected to the compressor, the compressor is connected to the first heat exchanger, the first heat exchanger is connected to the internal combustion engine, the first heat exchanger is connected to the recuperator, the recuperator is connected to the turbine, the turbine, the generator, and the compressor are all fixed to the rotating shaft, the turbine is also connected to the third heat exchanger, the third heat exchanger is connected to the internal combustion engine, and the third heat exchanger is also connected to the pressure vessel.

[0009] The utility model utilizes supercritical carbon dioxide to expand and do work on the turbine after the temperature is increased in the closed-loop system of the utility model. The turbine drives the generator and the compressor connected coaxially to rotate, enabling the generator to generate electricity and enabling the compressor to increase the pressure of supercritical carbon dioxide. After expanding and doing work, the pressure of supercritical carbon dioxide decreases. There is still a large amount of heat in the supercritical carbon dioxide after pressure reduction. Therefore, the heat in the supercritical carbon dioxide is recovered through the second heat exchanger and / or the third heat exchanger, and then the supercritical carbon dioxide is cooled by a cooler and finally enters the closed-loop system. Description of the Drawings

[0010] Figure 1 It is a schematic diagram of the first supercritical carbon dioxide power generation system.

[0011] Figure 2 It is a schematic diagram of the second supercritical carbon dioxide power generation system.

[0012] Reference Numerals: Pressure vessel 1, Generator 2, Compressor 3, Recuperator 4, First heat exchanger 5, Internal combustion engine 6, Turbine 7, Rotating shaft 8, Second heat exchanger 9, Cooler 10, Third heat exchanger 11. Detailed Description of the Invention

[0013] The following further describes the present utility model in detail in conjunction with the drawings and the specific embodiments.

[0014] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation.

[0015] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0016] In the present utility model, unless otherwise clearly specified and defined, terms such as "installed", "connected", "joined", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0017] In the present utility model, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature has a lower horizontal height than the second feature.

[0018] Embodiment 1

[0019] As Figure 1 shown, the supercritical carbon dioxide power generation system of the present utility model includes a pressure vessel 1 for storing supercritical carbon dioxide, a generator 2, a compressor 3, a recuperator 4, a first heat exchanger 5, an internal combustion engine 6, a turbine 7, and a rotating shaft 8. The pressure vessel 1 is connected to the compressor 3, the compressor 3 is connected to the recuperator 4, the recuperator 4 is connected to the first heat exchanger 5, the first heat exchanger 5 is connected to the internal combustion engine 6. The first heat exchanger 5 preferably adopts a printed circuit board heat exchanger, and the internal combustion engine 6 preferably adopts an engine. The first heat exchanger 5 is connected to the turbine 7, and the turbine 7, the generator 2, and the compressor 3 are all fixed to the rotating shaft 8. The turbine 7 is also connected to the recuperator 4, and the recuperator 4 is connected to the pressure vessel 1.

[0020] It further includes a second heat exchanger 9 located between the recuperator 4 and the pressure vessel 1, and the second heat exchanger 9 is respectively connected to the recuperator 4 and the pressure vessel 1. It further includes a cooler 10 located between the second heat exchanger 9 and the pressure vessel 1, and the cooler 10 is respectively connected to the second heat exchanger 9 and the pressure vessel 1.

[0021] The working process of this embodiment is as follows: The generator 2 operates to drive the rotation of the rotating shaft 8. The rotating shaft 8 drives the compressor 3 and the turbine 7 to rotate. The supercritical carbon dioxide output from the pressure vessel 1 enters the compressor 3. After being pressurized by the compressor 3, the supercritical carbon dioxide enters the recuperator 4. The recuperator 4 preheats the supercritical carbon dioxide. The preheated supercritical carbon dioxide flows to the first heat exchanger 5. There is exhaust gas discharged from the internal combustion engine 6 in the first heat exchanger 5. Therefore, the supercritical carbon dioxide exchanges heat with the exhaust gas discharged from the internal combustion engine 6 in the first heat exchanger 5 to increase its temperature. The supercritical carbon dioxide with increased temperature enters the turbine 7 to expand and do work, increasing the rotational speed of the turbine 7. The turbine 7 drives the generator 2 and the compressor 3 connected coaxially to rotate. When the rotational speed of the rotating shaft 8 increases to the set value (the rotational speed of the rotating shaft 8 is detected by a rotational speed sensor), for example, 2000 revolutions per minute, the generator 2 is powered off, and only the turbine 7 drives the generator 2 to operate. After the supercritical carbon dioxide completes the expansion work in the turbine 7, it is output to the recuperator 4. Since the supercritical carbon dioxide is still in a high-temperature state (above 500 °C) at this time, this supercritical carbon dioxide preheats the supercritical carbon dioxide output from the compressor 3. The supercritical carbon dioxide in a high-temperature state output from the recuperator 4 flows to the second heat exchanger 9 to exchange heat with the heat transfer medium in the second heat exchanger 9. The heat transfer medium in the second heat exchanger 9 preferably uses water. The input end of the second heat exchanger 9 is connected to a water pipe. After heat exchange, the second heat exchanger 9 can output hot water. After the supercritical carbon dioxide is cooled at the second heat exchanger 9, its temperature is still relatively high. Therefore, a cooler 10 is used to further cool the supercritical carbon dioxide. The cooler 10 includes a coil, fins, and a blower. The fins are installed on the coil. The supercritical carbon dioxide flows along the coil. The airflow generated by the blower acts on the fins and the coil, thereby dissipating heat from the fins and the coil, and further reducing the temperature of the supercritical carbon dioxide. The supercritical carbon dioxide with reduced temperature flows into the pressure vessel 1.

[0022] Embodiment 2

[0023] As Figure 2The shown supercritical carbon dioxide power generation system includes a pressure vessel 1 for storing supercritical carbon dioxide, a generator 2, a compressor 3, a recuperator 4, a first heat exchanger 5, an internal combustion engine 6, a turbine 7, a rotating shaft 8, and a third heat exchanger 11. The pressure vessel 1 is connected to the compressor 3, the compressor 3 is connected to the first heat exchanger 5, and the first heat exchanger 5 is connected to the internal combustion engine 6. The first heat exchanger 5 is a lubricating oil heat exchanger, and the internal combustion engine 6 is a gas turbine. The first heat exchanger 5 is connected to the recuperator 4, the recuperator 4 is connected to the turbine 7, and the turbine 7, the generator 2, and the compressor 3 are all fixed to the rotating shaft 8. The turbine 7 is further connected to the third heat exchanger 11, the third heat exchanger 11 is connected to the internal combustion engine 6, and the third heat exchanger 11 is also connected to the pressure vessel 1.

[0024] It further includes a second heat exchanger 9 located between the third heat exchanger 11 and the pressure vessel 1, and the second heat exchanger 9 is respectively connected to the third heat exchanger 11 and the pressure vessel 1. It further includes a cooler 10 located between the second heat exchanger 9 and the pressure vessel 1, and the cooler 10 is respectively connected to the second heat exchanger 9 and the pressure vessel 1.

[0025] The working process of this embodiment is as follows: The generator 2 operates to drive the rotation of the rotating shaft 8. The rotating shaft 8 drives the compressor 3 and the turbine 7 to rotate. The supercritical carbon dioxide output from the pressure vessel 1 enters the compressor 3. After being pressurized by the compressor 3, the supercritical carbon dioxide enters the first heat exchanger 5, that is, enters the lubricating oil heat exchanger. Since the first heat exchanger 5 is connected to the internal combustion engine 6, the lubricating oil required by the internal combustion engine 6 exchanges heat with the supercritical carbon dioxide at the first heat exchanger 5. The supercritical carbon dioxide cools the lubricating oil, and the supercritical carbon dioxide obtains preheating and its temperature increases. After preheating, the supercritical carbon dioxide reaches the recuperator 4. Since the exhaust gas output from the internal combustion engine 6 is transported to the recuperator 4, therefore, at the recuperator 4, the supercritical carbon dioxide exchanges heat with the exhaust gas output from the internal combustion engine 6. After the supercritical carbon dioxide obtains a temperature increase at the recuperator 4, it enters the turbine 7 to expand and do work, increasing the rotational speed of the turbine 7. The turbine 7 drives the generator 2 and the compressor 3 connected coaxially to rotate. When the shaft speed of the rotating shaft 8 increases to the set value (the rotational speed of the rotating shaft 8 is detected by a rotational speed sensor), for example, 2000 revolutions per minute, the generator 2 is powered off, and only the turbine 7 drives the generator 2 to operate. After the supercritical carbon dioxide completes the expansion and work in the turbine 7, it is output to the third heat exchanger 11. At the third heat exchanger 11, it exchanges heat with the fuel required for the operation of the internal combustion engine 6, increasing the temperature of the fuel, so that the fuel enters the internal combustion engine 6 to improve the combustion efficiency of the fuel. After the supercritical carbon dioxide exchanges heat with the fuel, its temperature will decrease, but its temperature is still in a relatively high state (above 200 °C). Therefore, the supercritical carbon dioxide output from the third heat exchanger 11 flows to the second heat exchanger 9 to exchange heat with the heat exchange medium in the second heat exchanger 9. The heat exchange medium in the second heat exchanger 9 preferably uses water. The input end of the second heat exchanger 9 is connected to the tap water pipe. After heat exchange, the second heat exchanger 9 can output hot water. After the supercritical carbon dioxide cools down at the second heat exchanger 9, its temperature is still relatively high. Therefore, a cooler 10 is used to further cool the supercritical carbon dioxide. The cooler 10 includes a coiled pipe, fins, and a blower. The fins are installed on the coiled pipe. The supercritical carbon dioxide flows along the coiled pipe. The airflow generated by the blower acts on the fins and the coiled pipe, thereby dissipating heat from the fins and the coiled pipe, and further reducing the temperature of the supercritical carbon dioxide. After the temperature is reduced, the supercritical carbon dioxide flows into the pressure vessel 1.

[0026] For the pressure vessel 1 in Embodiments 1 and 2, it can avoid pressure fluctuations and distortion of the compressor inlet flow field, and at the same time provide a buffer for temperature and pressure control. When the temperature is high, the power of the cooler 10 is increased and mixed into the pressure vessel 1 to play a buffer role in mixing and temperature reduction.

Claims

1. A supercritical carbon dioxide circulation power generation system, comprising a pressure container (1) for storing supercritical carbon dioxide and a generator (2), characterized in that: The pressure vessel (1) further comprises a compressor (3), a regenerator (4), a first heat exchanger (5), an internal combustion engine (6), a turbine (7), and a rotating shaft (8); the pressure vessel (1) is connected to the compressor (3), the compressor (3) is connected to the regenerator (4), the regenerator (4) is connected to the first heat exchanger (5), the first heat exchanger (5) is connected to the internal combustion engine (6), the first heat exchanger (5) is connected to the turbine (7), the turbine (7), the generator (2), and the compressor (3) are all fixed to the rotating shaft (8), the turbine (7) is also connected to the regenerator (4), and the regenerator (4) is connected to the pressure vessel (1).

2. The supercritical carbon dioxide cycle power generation system according to claim 1, characterized in that: It also includes a second heat exchanger (9) located between the regenerator (4) and the pressure container (1), and the second heat exchanger (9) is connected to the regenerator (4) and the pressure container (1) respectively.

3. The supercritical carbon dioxide cycle power generation system according to claim 2, characterized in that: It also includes a cooler (10) located between the second heat exchanger (9) and the pressure vessel (1), and the cooler (10) is connected to the second heat exchanger (9) and the pressure vessel (1) respectively.

4. The supercritical carbon dioxide cycle power generation system according to any one of claims 1 to 3, characterized in that: The first heat exchanger (5) is a printed circuit board type heat exchanger.

5. A supercritical carbon dioxide circulation power generation system, comprising a pressure container (1) for storing supercritical carbon dioxide and a generator (2), characterized in that: The pressure vessel (1) further comprises a compressor (3), a regenerator (4), a first heat exchanger (5), an internal combustion engine (6), a turbine (7), a rotating shaft (8), and a third heat exchanger (11); the pressure vessel (1) is connected to the compressor (3), the compressor (3) is connected to the first heat exchanger (5), the first heat exchanger (5) is connected to the internal combustion engine (6), the first heat exchanger (5) is connected to the regenerator (4), the regenerator (4) is connected to the turbine (7), the turbine (7), the generator (2), and the compressor (3) are all fixed to the rotating shaft (8), the turbine (7) is also connected to the third heat exchanger (11), the third heat exchanger (11) is connected to the internal combustion engine (6), and the third heat exchanger (11) is also connected to the pressure vessel (1).

6. The supercritical carbon dioxide cycle power generation system according to claim 5, characterized in that: It also includes a second heat exchanger (9) located between the third heat exchanger (11) and the pressure container (1), and the second heat exchanger (9) is connected to the third heat exchanger (11) and the pressure container (1) respectively.

7. The supercritical carbon dioxide cycle power generation system according to claim 6, characterized in that: It also includes a cooler (10) located between the second heat exchanger (9) and the pressure vessel (1), and the cooler (10) is connected to the second heat exchanger (9) and the pressure vessel (1) respectively.

8. The supercritical carbon dioxide cycle power generation system according to any one of claims 5 to 7, characterized in that: The first heat exchanger (5) is a lubricating oil heat exchanger, and the internal combustion engine (6) is a gas turbine.

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