Supercritical carbon dioxide Brayton cycle system and power generation main machine thereof

Abstract

The invention provides a supercritical carbon dioxide Brayton cycle system and a power generation host thereof, the power generation host is of an integrated structure, a power generation unit, a compression unit and a turbine unit are sequentially arranged in a shell, rotors of the power generation unit, the compression unit and the turbine unit are coaxial, the power generation unit, the compression unit and the turbine unit are located in different cavities in the shell, and the cavities where the power generation unit, the compression unit and the turbine unit are located are sealed and isolated. According to the supercritical carbon dioxide Brayton cycle system and the power generation main machine thereof, the advantages of the supercritical carbon dioxide Brayton cycle can be brought into full play, and the utilization mode and efficiency of distributed heat energy difficult to collect are flexibly improved in a multi-purpose mode. According to the power generation host, a power generation unit, a compression unit and a turbine unit are integrally designed and are jointly arranged in the same shell; therefore, compared with static sealing only needed by the outside, the overall sealing performance is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal power generation, and in particular relates to a supercritical carbon dioxide Brayton cycle system and a power generation host thereof. Background Art

[0002] In recent years, the application of supercritical carbon dioxide (sCO2) in the Brayton cycle has attracted widespread attention. In addition to the sCO2 cycle, the existing hot end utilization methods include steam Rankine cycle (SRC) and organic Rankine cycle (ORC). However, ORC is limited to low heat source temperatures below 300°C, and SRC occupies a large area; and the main disadvantage of these two utilization methods is that the irreversible loss of the heat exchanger is large. Unlike conventional power cycles such as SRC and ORC, the sCO2 power cycle uses CO2 in a supercritical state as a working fluid in all or most stages of the cycle. Compared with the existing steam Rankine cycle, the supercritical carbon dioxide Brayton cycle has the advantages of high cycle efficiency, low compression power consumption, small system size, large cost reduction potential, a wide range of applicable heat source quality, and low system noise. In the context of increasing attention to energy conservation and emission reduction, the efficient utilization of thermal energy and waste heat is an important means to achieve the "dual carbon" goal. Therefore, the application of supercritical carbon dioxide Brayton cycle to waste heat power generation has far-reaching technical prospects.

[0003] However, the supercritical carbon dioxide Brayton cycle technology is still immature. This is mainly reflected in: the design and manufacture of equipment components are difficult, there is a lack of experience in the construction and operation of the circulation system, and distributed unstable waste heat sources are difficult to collect and effectively utilize; the existing academic achievements are mostly in the theoretical simulation stage. At present, only some research institutions at home and abroad have conducted laboratory-level research on supercritical Brayton cycle power generation devices, and there is still a large gap from commercial application. The difficulties that hinder the implementation of related power generation hosts are mainly: (1) The pressure of the circulating working fluid is high, and it is difficult to achieve sealing; (2) The rotor in the device requires a high speed, and the temperature of the hot end is high, so the device is relatively complex and bulky. Even if it is miniaturized, the efficiency is low; (3) There is a lack of practical design solutions that can solve the problem. Immature structural design solutions bring great obstacles to the development and development of characteristics. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a supercritical carbon dioxide Brayton cycle system and a power generation host thereof, so as to solve the practical problems of the related power generation host.

[0005] The present invention achieves the above technical objectives through the following technical means.

[0006] A supercritical carbon dioxide Brayton cycle power generation host: an integrated structure, in which a power generation unit, a compression unit, and a turbine unit are sequentially arranged in a shell, the rotors of the three are coaxial, and the three are located in different cavities in the shell, and the cavities where the three are located are respectively provided with sealing isolation.

[0007] Furthermore, the housing is provided with:

[0008] A motor cavity, used for arranging the power generation unit;

[0009] A compressor chamber, used for arranging the compression unit, with a compressor inlet and a compressor outlet provided on the side wall;

[0010] The turbine casing cavity is used to set the turbine unit, and the side wall is provided with a turbine inlet and the end is provided with a turbine outlet.

[0011] Furthermore, in the motor cavity, the main shaft where the rotor is located is supported by bearings at both ends of the cavity, and the bearing seat is an elastic ring with variable rigidity or a squirrel cage elastic support structure.

[0012] Furthermore, the power generation unit is an integrated generator.

[0013] Furthermore, the compressor chamber is divided along the axis into:

[0014] A compressor inlet stabilizing cavity, a cross-section seal is provided between it and the motor cavity, and a side wall of the cavity is provided with the compressor inlet;

[0015] A compressor outlet stabilizing chamber, in which a centrifugal impeller is arranged, and a side wall of which is provided with the compressor outlet;

[0016] The compressor inlet stabilizing chamber and the compressor outlet stabilizing chamber are connected along the axis through a connecting pipe, the connecting pipe serves as the working medium inlet of the centrifugal impeller, and the working medium outlet of the centrifugal impeller is connected to the compressor outlet stabilizing chamber.

[0017] Furthermore, the centrifugal impeller and the turbine constituting the turbine unit are an integrated structure, and the blades of the two are respectively arranged on both sides of the same wheel disc; a comb-tooth labyrinth seal is used between the wheel disc and the casing to separate the compressor outlet stabilization chamber and the turbine casing chamber.

[0018] Furthermore, the wheel disc is a hollow structure, and the inner side is negative pressure or vacuum relative to the atmospheric pressure.

[0019] A supercritical carbon dioxide Brayton cycle system comprises the above-mentioned power generation host.

[0020] Furthermore, the pipeline flow direction of the circulation system is: heating module→turbine unit of the power generation host→heat source side of the regenerator→cooling module→compression unit of the power generation host→cold source side of the regenerator→heating module.

[0021] Furthermore, the cooling module includes a liquid cooling radiator and an air cooling radiator, which are connected in series or in parallel;

[0022] The heat source of the heating module is one or more of the waste heat of an onboard power device, the recovered heat of an onboard cooling device, and radioactive isotopes.

[0023] The beneficial effects of the present invention are:

[0024] (1) The present invention provides a supercritical carbon dioxide Brayton cycle system and a power generation host thereof, which can give full play to the advantages of the supercritical carbon dioxide Brayton cycle and flexibly and multi-purposely improve the utilization mode and efficiency of distributed difficult-to-collect thermal energy.

[0025] (2) The power generating unit of the present invention integrates the power generating unit, the compression unit and the turbine unit into an integrated design and places them together in the same housing; therefore, only static seals are required relative to the outside world, which improves the overall sealing performance. In comparison, the conventional design in which multiple functional units are arranged in a split manner and connected to each other by a transmission shaft passing through the cylinder body is difficult to ensure sufficiently effective sealing performance because dynamic seals are required at the transmission shaft, which makes it difficult to be practical and commercialized.

[0026] (3) The structural layout of the four cavities of the power generator of the present invention can better ensure the isolation and sealing performance between the three functional units (power generation unit, compression unit, and turbine unit) while achieving the coaxial design, thereby providing a technical basis for miniaturization and practicality of the main unit. In addition to playing the role of pressurizing the working fluid in the circulation system, the compression unit can also reduce the working fluid pressure on one side of the motor cavity, reduce the cross-sectional sealing pressure, reduce the risk or leakage of carbon dioxide working fluid into the motor cavity, and improve operational reliability.

[0027] (4) The centrifugal impeller and turbine of the present invention are integrated into one structure, which is conducive to further reducing the structural size. A hollow structure design is adopted therein, and a vacuum treatment is performed inside the hollow structure, thereby reducing the structural weight and improving the thermal insulation performance, reducing the heat transfer effect between the compression unit and the turbine unit, and improving the operating efficiency of the circulation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a structural diagram of the supercritical carbon dioxide Brayton cycle system in the embodiment of the present application;

[0029] Figure 2 This is a structural diagram of the appearance of the power generation host in the embodiment of the present application;

[0030] Figure 3 This is a structural diagram of the main generator cavity in an embodiment of the present application.

[0031] Reference numerals:

[0032] 1- generator main engine; 11- motor cavity;

[0033] 12-compressor inlet stabilization chamber; 121-compressor inlet;

[0034] 13-compressor outlet stabilization chamber; 131-compressor outlet;

[0035] 14-turbine casing cavity; 141-turbine inlet; 142-turbine outlet;

[0036] 2-heating module; 3-heat regenerator; 4-liquid cooling radiator; 5-air cooling radiator;

[0037] 61-turbine inlet pipe; 62-turbine outlet pipe; 63-compressor inlet pipe; 64-compressor outlet pipe;

[0038] 71-motor rotor; 72-centrifugal impeller; 73-turbine;

[0039] 81- rubber ring seal; 82- bearing; 83- section seal; 84- comb tooth labyrinth seal. DETAILED DESCRIPTION

[0040] Embodiments of the present invention are described in detail below, examples of the illustrated embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0041] Example 1, Supercritical Carbon Dioxide Brayton Cycle System

[0042] like Figure 1 The supercritical carbon dioxide Brayton cycle system given in the embodiment of the present application is shown, including a power generation host 1, a heating module 2, a regenerator 3, and a cooling module. The power generation host 1 integrates a power generation unit, a compression unit, and a turbine unit, wherein:

[0043] (1) The inlet end of the turbine unit is connected to the outlet of the heating module 2 through the turbine inlet pipe 61;

[0044] (2) The outlet end of the turbine unit is connected to the heat source side inlet of the regenerator 3 through the turbine outlet pipe 62;

[0045] (3) The heat source side outlet of the regenerator 3 is connected to the cooling module inlet through a pipeline;

[0046] (4) The inlet end of the compression unit is connected to the outlet of the cooling module via the compressor inlet pipe 63;

[0047] (5) The outlet end of the compression unit is connected to the cold source side inlet of the regenerator 3 through the compressor outlet pipe 64;

[0048] (6) The cold source side outlet of the regenerator 3 is connected to the inlet of the heating module 2 through a pipeline.

[0049] All the above pipelines are sealed and detachable connections.

[0050] In this embodiment, the cooling module includes a liquid cooling radiator 4 and an air cooling radiator 5, which are connected in series. In actual settings, they can also be connected in parallel or in any one of the two according to actual needs, as well as other equivalent alternative heat dissipation forms.

[0051] The heating module 2 can use heat sources such as waste heat from an onboard power unit (engine), heat recovery from an onboard cooling unit, and radioactive isotopes.

[0052] The regenerator 3 may adopt a micro-channel or printed plate heat exchange structure.

[0053] When the above-mentioned supercritical carbon dioxide Brayton cycle system is working, the high-temperature and high-pressure carbon dioxide heated by the heating module 2 is passed into the turbine unit, driving the turbine therein to operate and do work, thereby driving the power generation unit to generate electricity; the carbon dioxide discharged from the turbine unit first flows into the regenerator 3 as the heat source of the regenerator 3, and then flows through the cooling module for cooling; the cooled carbon dioxide is passed into the compression unit for pressurization; the pressurized carbon dioxide is first preheated by the regenerator 3 and then sent to the heating module 2 again for circulation heating.

[0054] Example 2, Supercritical Carbon Dioxide Brayton Cycle Power Generation Main Unit

[0055] like Figure 2 and Figure 3 The main generator 1 in Example 1 is shown, and its shell is provided with four cavities along the central axis, namely, a motor cavity 11, a compressor inlet stabilizing cavity 12, a compressor outlet stabilizing cavity 13, and a turbine casing cavity 14, and the four cavities are coaxially arranged.

[0056] in:

[0057] (1) The motor cavity 11 is used to set the power generation unit. In this embodiment, the power generation unit adopts an integrated generator.

[0058] (2) The compressor inlet stabilizing chamber 12 and the compressor outlet stabilizing chamber 13 and their internal components together constitute the compression unit. The compressor inlet stabilizing chamber 12 has a compressor inlet 121 on its side wall for connecting to the compressor inlet pipe 63; the compressor outlet stabilizing chamber 13 has a compressor outlet 131 on its side wall for connecting to the compressor outlet pipe 64.

[0059] (3) The turbine casing 14 is used to constitute the turbine unit, and a turbine is arranged therein; a turbine inlet 141 is arranged on its side wall for connecting to the turbine inlet pipe 61; and a turbine outlet 142 is arranged at its end on the outer side for connecting to the turbine outlet pipe 62.

[0060] like Figure 3 As shown, the housing is a half-mounted structure, and the joints are sealed with rubber rings 81. A main shaft is provided along the central axis of the housing, and the main shaft crosses the four cavities; the motor rotor 71 of the power generation unit, the centrifugal impeller 72 of the compression unit, and the turbine 73 of the turbine unit are connected to the main shaft. Among them:

[0061] In the motor cavity 11, the two ends of the cavity support the main shaft through bearings 82; the corresponding bearing seat adopts a variable rigidity elastic ring or squirrel cage elastic support structure. A cross-section seal 83 is used between the motor cavity 11 and the compressor inlet stable cavity 12.

[0062] The compressor inlet stabilizing chamber 12 and the compressor outlet stabilizing chamber 13 are connected along the central axis through a connecting pipe. The centrifugal impeller 72 is located in the compressor outlet stabilizing chamber 13, and the connecting pipe serves as the working medium inlet of the centrifugal impeller 72, and the working medium outlet of the centrifugal impeller 72 is connected to the compressor outlet stabilizing chamber 13.

[0063] The centrifugal impeller 72 and the turbine 73 are of an integrated structure, and the two share a wheel disc, and the blades of the two are respectively arranged on both sides of the wheel disc; wherein the turbine 73 is located in the turbine casing cavity 14. The compressor outlet stabilizing cavity 13 and the turbine casing cavity 14 are separated by the wheel disc; and a comb-tooth-type labyrinth seal 84 is used between the wheel disc and the housing for isolation.

[0064] In this embodiment, the interior of the wheel disc is a hollow structure (the gray part in the figure), and the hollow cavity adopts a suction process to discharge gas during production and processing to form a negative pressure state to reduce weight and heat conduction.

[0065] When the above-mentioned power generation main unit 1 is working, the heated carbon dioxide working medium is introduced into the turbine casing chamber 14 to drive the turbine 73 to rotate, and then the centrifugal impeller 72 and the motor rotor 71 are driven to operate synchronously through the common main shaft. The motor rotor 71 operates to realize the power generation function; the centrifugal impeller 72 operates to pressurize the carbon dioxide working medium in the supercritical carbon dioxide Brayton cycle system.

[0066] In the description of the present invention, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0067] The present invention is not limited to the above-mentioned embodiments. Any obvious improvement, substitution or deformation that can be made by those skilled in the art without departing from the essential content of the present invention belongs to the protection scope of the present invention.

Claims

1. A supercritical carbon dioxide Brayton cycle power generation host, characterized in that: It is an integrated structure, in which a power generation unit, a compression unit and a turbine unit are arranged in sequence in the shell, the rotors of the three are coaxial, and the three are located in different cavities in the shell, and the cavities where the three are located are respectively provided with sealing isolation.

2. The supercritical carbon dioxide Brayton cycle power generation host according to claim 1, characterized in that: The housing is provided with: A motor cavity (11) for arranging the power generation unit; A compressor chamber, used for arranging the compression unit, with a compressor inlet (121) and a compressor outlet (131) being arranged on a side wall; The turbine casing cavity (14) is used to arrange the turbine unit, and has a turbine inlet (141) on its side wall and a turbine outlet (142) at its end.

3. The supercritical carbon dioxide Brayton cycle power generation host according to claim 2, characterized in that: In the motor cavity (11), the two ends of the cavity support the main shaft where the rotor is located through bearings (82) respectively, and the bearing seat is an elastic ring with variable rigidity or a squirrel cage type elastic support structure.

4. The supercritical carbon dioxide Brayton cycle power generation host according to claim 2, characterized in that: The power generation unit is an integrated generator.

5. The supercritical carbon dioxide Brayton cycle power generation host according to claim 2, characterized in that: The compressor cavity is divided along the axis into: A compressor inlet stabilizing chamber (12), a cross-section seal (83) being provided between the compressor inlet stabilizing chamber (12) and the motor chamber (11), and a compressor inlet (121) being provided on a side wall thereof; A compressor outlet stabilization chamber (13), in which a centrifugal impeller (72) is arranged, and a side wall of which is provided with the compressor outlet (131); The compressor inlet stabilizing chamber (12) and the compressor outlet stabilizing chamber (13) are connected along the axis via a connecting pipe, the connecting pipe serving as the working fluid inlet of the centrifugal impeller (72), and the working fluid outlet of the centrifugal impeller (72) is connected to the compressor outlet stabilizing chamber (13).

6. The supercritical carbon dioxide Brayton cycle power generation host according to claim 5, characterized in that: The centrifugal impeller (72) and the turbine (73) constituting the turbine unit are of an integrated structure, and the blades of the two are respectively arranged on both sides of the same wheel disc; a comb-tooth-type labyrinth seal is used between the wheel disc and the shell to separate the compressor outlet stabilization chamber (13) and the turbine casing chamber (14).

7. The supercritical carbon dioxide Brayton cycle power generation host according to claim 6, characterized in that: The wheel disc is a hollow structure, and the inner side is negative pressure or vacuum relative to the atmospheric pressure.

8. A supercritical carbon dioxide Brayton cycle system, characterized in that: It comprises a power generation host as described in any one of claims 1 to 7.

9. The supercritical carbon dioxide Brayton cycle system according to claim 8, characterized in that: The pipeline flow direction of the circulation system is: heating module (2) → turbine unit of the main generator → heat source side of the regenerator (3) → cooling module → compression unit of the main generator → cold source side of the regenerator (3) → heating module (2).

10. The supercritical carbon dioxide Brayton cycle system according to claim 9, characterized in that: The cooling module comprises a liquid cooling radiator (4) and an air cooling radiator (5), which are connected in series or in parallel; The heat source of the heating module (2) is one or more of the waste heat of an onboard power device, the recovered heat of an onboard cooling device, and radioactive isotopes.

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