A supercritical CO2 power generation system

Abstract

The embodiment of the present disclosure provides a supercritical CO2 power generation system, comprising a pressure stabilizing tank, a compressor, a regenerator, a heat source, a power generation turbine, a pre-cooler, a high-speed centrifugal separator, a centripetal turbine, a first shutoff valve and a second shutoff valve; the high-speed centrifugal separator comprises an inlet, a supercritical CO2 outlet, a solid impurity outlet and a lubricating oil droplet outlet; high-purity supercritical CO2 is separated out from the system in line by using the high-speed centrifugal separator coaxial with the centripetal turbine, the work of the bypass equipment is not affected while being filtered in line, and the in-line filtering of the supercritical CO2 is realized.

Description

Technical Field

[0001] The embodiments disclosed herein belong to the field of supercritical CO2 power generation technology, specifically relating to a supercritical CO2 power generation system. Background Technology

[0002] Supercritical CO2 power generation systems are advanced power cycles and systems that use supercritical CO2 as the working fluid. They offer advantages such as high power generation efficiency, compact system structure, high flexibility, and good heat source applicability, and are receiving significant research attention from both academia and industry. However, after long-term operation under high temperature and high pressure conditions, lubricating oil droplets from rotating equipment and solid impurities from the inner walls of pipes may mix into the supercritical CO2 working fluid, causing blockage of the microchannel heat exchanger and damage to the rotating mechanical blades, threatening the safe and stable operation of the system and requiring shutdown for cleaning. Summary of the Invention

[0003] The embodiments disclosed herein are intended to at least address one of the technical problems existing in the prior art, and to provide a supercritical CO2 power generation system.

[0004] Embodiments of this disclosure provide a supercritical CO2 power generation system, including a pressure stabilizing tank, a compressor, a regenerator, a heat source, a power generation turbine, a precooler, a high-speed centrifugal separator, a centrifugal turbine, a first shut-off valve, and a second shut-off valve; the high-speed centrifugal separator includes an inlet, a supercritical CO2 outlet, a solid impurity outlet, and a lubricating oil droplet outlet;

[0005] The compressor's inlet and outlet are respectively connected to the outlet of the pressure stabilizing tank and the low-temperature side inlet of the regenerator; the regenerator's low-temperature side outlet is connected to the inlet of the heat source; the heat source's first and second outlets are respectively connected to the inlet of the power generation turbine and the inlet of the centrifugal turbine; the power generation turbine's outlet is connected to the first high-temperature inlet of the regenerator; and the centrifugal turbine's outlet is connected to the second high-temperature inlet of the regenerator. The precooler's inlet and first outlet are respectively connected to the regenerator's high-temperature outlet and the high-speed centrifugal separator's inlet.

[0006] A first shut-off valve is connected in series between the outlet of the precooler and the inlet of the high-speed centrifugal separator; a second shut-off valve is connected in series between the second outlet of the heat source and the inlet of the centripetal turbine; the supercritical CO2 outlet of the high-speed centrifugal separator is connected to the inlet of the pressure stabilizing tank; the centripetal turbine is coaxially arranged and connected to the high-speed centrifugal separator.

[0007] Optionally, the second outlet of the precooler is connected to the inlet of the pressure stabilizing tank, and a third shut-off valve is connected in series between the second outlet of the precooler and the inlet of the pressure stabilizing tank.

[0008] Optionally, it may also include an electric motor and a generator;

[0009] The electric motor is coaxially connected to the compressor, and the generator is coaxially connected to the power turbine.

[0010] Optionally, the supercritical CO2 power generation system includes two operating modes: online filtration and offline filtration.

[0011] When in online filtration mode, the third shut-off valve is closed, and the first and second shut-off valves are open.

[0012] When in offline filtration mode, the third shut-off valve opens, while the first and second shut-off valves close.

[0013] Optionally, the first outlet of the heat source is connected to the inlet of the power generation turbine via a first pipeline, and the first outlet of the heat source is connected to the inlet of the centripetal turbine via a second pipeline;

[0014] The diameter of the first pipeline is larger than the diameter of the second pipeline.

[0015] Optionally, the distances from the supercritical CO2 outlet, lubricating oil droplet outlet, and solid impurity outlet to the rotating shaft of the high-speed centrifugal separator increase sequentially.

[0016] Optionally, the inlet, supercritical CO2 outlet, lubricating oil droplet outlet, and solid impurity outlet are arranged sequentially from the top to the bottom of the high-speed centrifugal separator.

[0017] The supercritical CO2 power generation system of the present disclosure has the following beneficial effects:

[0018] 1. Achieves online, continuous filtering and flexible switching. The supercritical CO2 power generation system of the embodiments of this disclosure does not require shutdown and can continuously filter during system operation, fundamentally eliminating losses caused by shutdown.

[0019] 2. High separation accuracy, avoiding clogging of core equipment. Separation is achieved by utilizing the density differences of different components in the mixture, actively removing non-working fluid components from the system, rather than relying on traditional methods such as filters to collect and intercept them, thus preventing the purification device itself from becoming a source of clogging. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a supercritical CO2 power generation system according to an embodiment of the present disclosure. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solutions of this disclosure, the disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 1 As shown, a supercritical CO2 power generation system includes a pressure tank 1, a compressor 2, a regenerator 3, a heat source 4, a power generation turbine 5, a precooler 6, a high-speed centrifugal separator 7, a centripetal turbine 8, a first shut-off valve 9, and a second shut-off valve 10. The high-speed centrifugal separator 7 includes an inlet 71, a supercritical CO2 outlet 72, a solid impurity outlet 73, and a lubricating oil droplet outlet 74. The inlet and outlet of the compressor 2 are respectively connected to the outlet of the pressure tank 1 and the low-temperature inlet of the regenerator 3. The low-temperature outlet of the regenerator 3 is connected to the inlet of the heat source 4. The first and second outlets of the heat source 4 are respectively connected to the inlet of the power generation turbine 5 and the inlet of the centripetal turbine 8. The outlet of the power generation turbine 5 is connected to the first high-temperature inlet of the regenerator 3, and the outlet of the centripetal turbine 8 is connected to the second high-temperature inlet of the regenerator 3. The inlet and first outlet of the precooler 6 are respectively connected to the high-temperature outlet of the regenerator 3 and the inlet 71 of the high-speed centrifugal separator 7.

[0023] A first shut-off valve 9 is connected in series between the outlet of the precooler 6 and the inlet of the high-speed centrifugal separator 7. A second shut-off valve 10 is connected in series between the second outlet of the heat source 4 and the inlet of the centripetal turbine 8. The supercritical CO2 outlet 72 of the high-speed centrifugal separator 7 is connected to the inlet of the pressure stabilizing tank 1. The centripetal turbine 8 is coaxially connected to the high-speed centrifugal separator 7.

[0024] Furthermore, the second outlet of the precooler 6 is connected to the inlet of the pressure stabilizing tank 1, and a third shut-off valve 11 is connected in series between the second outlet of the precooler 6 and the inlet of the pressure stabilizing tank 1.

[0025] The supercritical CO2 power generation system also includes a motor 200 and a generator 300. The motor 200 is coaxially connected to the compressor 2, and the generator 300 is coaxially connected to the power generation turbine 5.

[0026] The first outlet of the heat source 4 is connected to the inlet of the power generation turbine 5 via a first pipe 12, and the first outlet of the heat source 4 is connected to the inlet of the centripetal turbine 8 via a second pipe 13. The diameter of the first pipe 12 is larger than the diameter of the second pipe 13.

[0027] The supercritical CO2 power generation system includes two operating modes: online filtration and offline filtration. In online filtration mode, the third shut-off valve 11 is closed, while the first shut-off valve 9 and the second shut-off valve 10 are open.

[0028] Specifically, such as Figure 1As shown, when the online filter is activated, the first shut-off valve 9 and the second shut-off valve 10 are opened, and the third shut-off valve 11 is closed. The circulation process at this time is as follows: supercritical CO2 flows out from the outlet of the pressure tank 1 and enters the compressor 2, the low-temperature side of the regenerator 3 and the heat source 4 in sequence to complete the compression, preheating and heat absorption process.

[0029] Subsequently, most of the supercritical CO2 flows into the power generation turbine 5 through the first pipe 12 to perform work. It then flows sequentially through the first high-temperature inlet of the regenerator 3 and the inlet of the precooler 6, respectively, into the high-temperature side of the regenerator 3 and the precooler 6, completing reheating and cooling. Afterward, it flows into the high-speed centrifugal separator 7, where it is filtered and exits from the supercritical CO2 outlet 72 into the pressure stabilizing tank 1, completing one thermodynamic cycle. A small portion of the supercritical CO2 flows into the centrifugal turbine 8 through the second pipe 13, then through the second high-temperature inlet of the regenerator 3 into the high-temperature side of the regenerator 3 to complete reheating. This supercritical CO2, along with the supercritical CO2 flowing into the high-temperature side of the regenerator 3 through the first pipe 12, flows out of the regenerator 4 and into the precooler 6.

[0030] The high-speed centrifugal separator 7 is driven by a coaxially arranged centripetal turbine 8, with a rotational speed of tens of thousands of revolutions per minute. The compressor 2 is driven by a coaxially arranged electric motor 200, connected to the plant's power supply. The generator 300 is driven by a coaxially arranged power turbine 5, realizing the conversion of thermal energy into mechanical energy into electrical energy. The regenerator 3 simultaneously experiences heat exchange with three fluids: supercritical CO2 entering through the first high-temperature inlet on the high-temperature side of the regenerator 3 and supercritical CO2 entering through the second high-temperature inlet on the high-temperature side of the regenerator 3, both releasing heat to the supercritical CO2 on the low-temperature side of the regenerator 3. It is easy to understand that the flow rate distribution is determined by the inner diameter of the first pipe 12 and the second pipe 13.

[0031] Furthermore, the distances from the supercritical CO2 outlet 72, lubricating oil droplet outlet 74, and solid impurity outlet 73 to the rotating shaft of the high-speed centrifugal separator 7 increase sequentially. That is, the outlet positions are set according to the density and the magnitude of the centrifugal force.

[0032] Furthermore, the inlet 71, the supercritical CO2 outlet 72, the lubricating oil droplet outlet 74, and the solid impurity outlet 73 are arranged sequentially from the top to the bottom of the high-speed centrifugal separator 7.

[0033] When the supercritical CO2 power generation system is in offline filtration mode, the third shut-off valve 11 is opened, and the first shut-off valve 9 and the second shut-off valve 10 are closed.

[0034] Specifically, such as Figure 1As shown, when the online filter is shut down, the first shut-off valve 9 and the second shut-off valve 10 are closed, and the third shut-off valve 11 is opened. The circulation process at this time is as follows: Supercritical CO2 flows out from the outlet of the pressure tank 1 and sequentially enters the compressor 2, the low-temperature side of the regenerator 3, and the heat source 4, completing the compression, preheating, and heat absorption processes. All supercritical CO2 flows into the power generation turbine 5 through the first pipeline 12 to perform work, then sequentially flows into the high-temperature side of the regenerator 3 and the precooler 6 to complete reheating and cooling, and finally flows into the inlet of the pressure tank 1 to complete one thermodynamic cycle.

[0035] Among them, the regenerator 3 has two fluid heat exchangers. The supercritical CO2 entering from the first high-temperature inlet on the high-temperature side of the regenerator 3 releases heat to the supercritical CO2 on the low-temperature side of the regenerator 3.

[0036] The supercritical CO2 power generation system of this disclosure can achieve online, continuous filtration and free switching. The supercritical CO2 power generation system of this disclosure requires no downtime and can continuously filter during system operation, fundamentally eliminating losses caused by downtime.

[0037] The supercritical CO2 power generation system of this disclosure has high separation accuracy and can avoid clogging of core equipment. Separation is achieved by utilizing the density differences of different components in the mixture, actively removing non-working fluid components from the system, rather than relying on traditional methods such as filters for accumulation and interception, thus preventing the purification device itself from becoming a source of blockage.

[0038] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. A supercritical CO2 power generation system, characterized in that, It includes a pressure stabilizing tank, a compressor, a regenerator, a heat source, a power generation turbine, a precooler, a high-speed centrifugal separator, a centrifugal turbine, a first shut-off valve, and a second shut-off valve; the high-speed centrifugal separator includes an inlet, a supercritical CO2 outlet, a solid impurity outlet, and a lubricating oil droplet outlet; The compressor's inlet and outlet are respectively connected to the outlet of the pressure stabilizing tank and the low-temperature side inlet of the regenerator; the regenerator's low-temperature side outlet is connected to the inlet of the heat source; the heat source's first and second outlets are respectively connected to the inlet of the power generation turbine and the inlet of the centrifugal turbine; the power generation turbine's outlet is connected to the first high-temperature inlet of the regenerator; and the centrifugal turbine's outlet is connected to the second high-temperature inlet of the regenerator. The precooler's inlet and first outlet are respectively connected to the regenerator's high-temperature outlet and the high-speed centrifugal separator's inlet. A first shut-off valve is connected in series between the outlet of the precooler and the inlet of the high-speed centrifugal separator; a second shut-off valve is connected in series between the second outlet of the heat source and the inlet of the centripetal turbine; the supercritical CO2 outlet of the high-speed centrifugal separator is connected to the inlet of the pressure stabilizing tank; the centripetal turbine is coaxially arranged and connected to the high-speed centrifugal separator. The second outlet of the precooler is connected to the inlet of the pressure stabilizing tank, and a third shut-off valve is connected in series between the second outlet of the precooler and the inlet of the pressure stabilizing tank. The supercritical CO2 power generation system includes two operating modes: online filtration and offline filtration. When in online filtration mode, the third shut-off valve is closed, and the first and second shut-off valves are open. When in offline filtration mode, the third shut-off valve is open, and the first and second shut-off valves are closed. The first outlet of the heat source is connected to the inlet of the power generation turbine via a first pipeline, and the first outlet of the heat source is connected to the inlet of the centripetal turbine via a second pipeline; the diameter of the first pipeline is larger than the diameter of the second pipeline.

2. The supercritical CO2 power generation system according to claim 1, characterized in that, It also includes electric motors and generators; The electric motor is coaxially connected to the compressor, and the generator is coaxially connected to the power turbine.

3. The supercritical CO2 power generation system according to claim 1, characterized in that, The distances from the supercritical CO2 outlet, lubricating oil droplet outlet, and solid impurity outlet to the shaft of the high-speed centrifugal separator increase sequentially.

4. The supercritical CO2 power generation system according to claim 3, characterized in that, The inlet, supercritical CO2 outlet, lubricating oil droplet outlet, and solid impurity outlet are arranged sequentially from the top to the bottom of the high-speed centrifugal separator.

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