Supercritical carbon dioxide cycle power generation system and power adjusting method thereof

Abstract

The invention provides a supercritical carbon dioxide circulation power generation system and a power adjusting method thereof. The circulation power generation system comprises a circulation pipeline, and a driving unit, a generator set, a heat regenerator assembly, a main heater, a flow divider, a precooler and a reheater which are arranged in the circulation pipeline. The driving unit and the generator set of the power generation system form split-axis layout, and a complex super-two system is mechanically decoupled, so that adjustable parameters are increased, and variable working conditions are more flexible. When variable working conditions are carried out, more than two working media in the system do not need to be discharged, and output power changes of the driving turbine and the power generation turbine are achieved by adjusting the opening degrees of the first adjusting valve, the second adjusting valve and the third adjusting valve. The rotating speed of the generator set is generally constant, the rotating speed of the driving set is adjustable, and the increased or decreased generated power is flexibly received and adjusted by the driving set so as to adapt to and cooperate with the variable power requirement on the premise of not discharging or increasing the system super-second working medium, and the stability and high efficiency of the system can still be ensured.

Description

Technical Field

[0001] The present application relates to the technical field of supercritical carbon dioxide cycle power generation, and in particular to a supercritical carbon dioxide cycle power generation system and a power regulation method thereof. Background Art

[0002] The supercritical carbon dioxide cycle power generation system benefits from the good thermal properties of carbon dioxide critical point: the critical conditions are easy to reach (30.978℃, 7.377MPa), the density in the supercritical state is close to that of liquid, the compression factor is 0.2-0.5, the surface tension is small, the thermal conductivity is larger than that of normal pressure gas, the viscosity is low, etc. It has the characteristics of high efficiency, compactness, and high economy.

[0003] Volumetric power regulation is one of the commonly used methods in closed-cycle power generation systems, with the advantages of convenient regulation and high efficiency under variable conditions. It is very effective in closed cycles where the working fluid is an ideal gas (such as helium), because the pressure and density of an ideal gas vary proportionally. Therefore, by reducing the mass flow of the system, the pressure and density of the working fluid will decrease, but the inlet volume flow of the turbine equipment will remain unchanged. The compressor and turbine operate at similar design points, and the cycle can maintain high efficiency over a larger power range.

[0004] However, the physical properties of carbon dioxide change nonlinearly or even suddenly near the critical point. During the volumetric regulation process, the reduction of the working fluid in the system will inevitably cause the main compressor inlet pressure to decrease to near the critical point, which may bring unpredictable system stability problems, making it difficult for the system to maintain its original stability and high efficiency.

[0005] In addition, the existing supercritical carbon dioxide cycle power generation system generally has a constant power generation capacity. When faced with changing operating conditions, it is impossible to flexibly adjust the power generation capacity and cannot cope with the changing power generation and power consumption conditions. Summary of the invention

[0006] The purpose of the present application is to provide a supercritical carbon dioxide cycle power generation system and a power regulation method thereof, which increases the number of adjustable parameters by setting a split-axis layout structure of a driving unit and a generator unit, and can flexibly adjust the system power generation power without discharging or increasing the system working fluid, thereby maintaining the stability and efficiency of the system while adapting to the power generation needs of variable working conditions.

[0007] The present application provides a supercritical carbon dioxide circulation power generation system, including a circulation pipeline and a driving unit, a generator unit, a regenerator assembly, a main heater, a diverter, a precooler and a reheater arranged in the circulation pipeline. The regenerator assembly includes a high-temperature regenerator, a low-temperature regenerator and a mixer. The driving unit includes a starter and a driving turbine and a main compressor driven by the starter. The generator unit includes an initiator and a power generation turbine and a recompressor connected to the initiator.

[0008] The two outlets of the splitter are connected to the main compressor inlet and the recompressor inlet respectively. A precooler is arranged between the splitter and the main compressor, and a first regulating valve is arranged between the splitter and the recompressor. The main compressor outlet is connected to the cold source side inlet of the low-temperature regenerator, and the cold source side outlet of the low-temperature regenerator and the recompressor outlet are connected to the two inlets of the mixer respectively; the outlet of the mixer is connected to the cold source side inlet of the high-temperature regenerator, and the cold source side outlet of the high-temperature regenerator is connected to the main heater inlet, and the main heater outlet is connected to the driving turbine inlet. The driving turbine outlet is divided into a first branch and a second branch. The first branch is connected to the power generation turbine inlet, and the second branch is connected to the heat source side inlet of the high-temperature regenerator. The second regulating valve and the reheater are arranged in sequence on the first branch, and the third regulating valve is arranged on the second branch. The power generation turbine outlet is connected to the heat source side inlet of the high-temperature regenerator, and the heat source side outlet of the high-temperature regenerator is connected to the heat source side inlet of the low-temperature regenerator, and the heat source side outlet of the low-temperature regenerator is connected to the splitter inlet. When working, supercritical carbon dioxide working fluid is filled into various places of the circulation pipeline.

[0009] In an practicable solution, the supercritical carbon dioxide cycle power generation system includes a storage tank storing carbon dioxide working fluid, and the storage tank is connected to a circulation pipeline from a low-temperature regenerator to an inlet of a diverter.

[0010] In an implementable solution, the inlet of the storage tank is connected to the circulation pipeline through an inlet valve, and the outlet of the storage tank is connected to the circulation pipeline through an outlet valve.

[0011] In an implementable solution, a pressure boosting device is provided in the storage tank, and the pressure boosting device is used to increase the pressure of the carbon dioxide working fluid at the outlet valve.

[0012] In an implementable solution, the first regulating valve, the second regulating valve and the third regulating valve are electric regulating valves. The supercritical carbon dioxide cycle power generation system includes a main control device, which is at least connected to the first regulating valve, the second regulating valve and the third regulating valve for adjusting the valve opening.

[0013] In an implementable solution, the main control device is connected to the main heater and the reheater in communication to control the heating power of the main heater and the reheater.

[0014] In an implementable solution, a pressure detection sensor is provided at the outlet of the driving turbine, and the pressure detection sensor is communicatively connected with a main control device, and the main control device regulates the heating power of the main heater according to the pressure information of the pressure detection sensor.

[0015] In a second aspect, the present application provides a power regulation method based on the aforementioned supercritical carbon dioxide cycle power generation system, comprising:

[0016] S1. Determine the real-time power generation W before adjusting the power m ;

[0017] S2. Determine the adjusted target power generation W t ;

[0018] S3, based on the target power generation W t The real-time power generation before adjustment W m The opening sizes of the first regulating valve, the second regulating valve and the third regulating valve are adjusted according to the size difference.

[0019] In one feasible solution, in step S3, based on the target power generation W t The real-time power generation before adjustment W m The step of adjusting the opening sizes of the first regulating valve, the second regulating valve and the third regulating valve according to the size difference of the first regulating valve, the second regulating valve and the third regulating valve comprises:

[0020] S31, determine the target power generation W t The real-time power generation before adjustment W m The power difference W t-m ;

[0021] S32, determine the power difference W t-m is the absolute value of is less than or equal to the first preset difference; if so, proceed to step S33; if not, proceed to step S34;

[0022] S33, keeping the current opening sizes of the first regulating valve, the second regulating valve and the third regulating valve unchanged;

[0023] S34, determine the target power generation W t Whether it is less than the real-time power generation W before adjustment m ; If W t Less than W m , then go to step S35; if W t Greater than W m , then proceed to step S36;

[0024] S35, reducing the opening of the second regulating valve, increasing the opening of the third regulating valve, and increasing the opening of the first regulating valve according to the preset unit opening amount;

[0025] S36, increasing the opening of the second regulating valve, decreasing the opening of the third regulating valve, and decreasing the opening of the first regulating valve according to the preset unit opening amount;

[0026] S37, determine the adjusted real-time power generation W a , and determine the adjusted real-time power generation W a and target power generation W t Is the absolute value of the difference less than or equal to the second preset difference; if so, complete the opening adjustment of the first regulating valve, the second regulating valve and the third regulating valve; if not, repeat steps S35 to S37, or repeat steps S36 to S37.

[0027] In an practicable solution, before step S3, the method further includes: S03, obtaining the outlet pressure P of the driving turbine before the regulating valve is adjusted. 0 ;

[0028] After step S3, the method further includes:

[0029] S4. Obtain the outlet pressure P of the driving turbine after the regulating valve is adjusted t ;

[0030] S5. Determine the outlet pressure P t With outlet pressure P 0 Is the absolute value of the difference between the pressure difference and the pressure difference less than or equal to the preset pressure difference? If so, keep the current heating power of the main heater unchanged; if not, adjust the heating power of the main heater and repeat steps S4 to S5 until the outlet pressure P t With outlet pressure P 0 The difference is controlled within a predetermined range.

[0031] Compared with the prior art, the beneficial effects of the present application include at least the following:

[0032] The supercritical carbon dioxide cycle power generation system of the present application includes a driving unit and a generator unit, forming a split-axis layout, which mechanically decouples the complex supercritical system, thereby increasing the number of adjustable parameters and making the operating conditions more flexible.

[0033] The supercritical carbon dioxide cycle power generation system of the present application does not need to discharge the super-two working fluid in the system (i.e., it does not need to use the variable volume method) when operating under variable working conditions (changing the power generation), but relies on adjusting the opening of the first, second, and third regulating valves to achieve the change of the output power of the driving turbine and the power generation turbine, rather than simply reducing or increasing the system pressure. The speed of the generator set is generally a constant speed, and the speed of the driving set is adjustable. The increased or decreased power generation is flexibly adjusted by the driving set to adapt to and cooperate with the demand for variable power. In the process of power adjustment, the system can still ensure the operating stability and high efficiency without discharging or increasing the super-two working fluid in the system.

[0034] For example, when operating at reduced power, there is no need to discharge the supercritical carbon dioxide in the system (i.e., there is no need to use the variable volume method). Instead, the output power of the driving turbine and the power generating turbine can be changed by adjusting the opening of the first, second, and third regulating valves, rather than simply reducing the system pressure. Therefore, the inlet condition of the main compressor will not reach the critical point, but will only remain relatively close to the critical point. As a result, the power generation regulation of the system can overcome the influence of the critical point of supercritical carbon dioxide, thereby ensuring the operating stability and high efficiency of the system during the power regulation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 It is a schematic diagram of the composition of a supercritical carbon dioxide cycle power generation system according to an embodiment of the present application.

[0037] Figure 2 It is a schematic diagram of the composition of another supercritical carbon dioxide cycle power generation system according to an embodiment of the present application.

[0038] Figure 3 The present invention is a flow chart of a power regulation method for a supercritical carbon dioxide cycle power generation system according to an embodiment of the present application.

[0039] In the figure: 1. driving unit; 11. starter; 12. driving turbine; 13. main compressor; 2. generator set; 21. starter; 22. power generation turbine; 23. recompressor; 3. regenerator assembly; 31. high-temperature regenerator; 32. low-temperature regenerator; 33. mixer; 4. main heater; 5. diverter; 6. precooler; 7. reheater; 8. storage tank; 81. inlet valve; 82. outlet valve; 101. first regulating valve; 102. second regulating valve; 103. third regulating valve; 100. circulation pipeline; 200. main control device; 300. pressure detection sensor. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0041] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0042] like Figure 1 As shown, the embodiment of the present application first provides a supercritical carbon dioxide circulation power generation system, including a circulation pipeline 100 and a driving unit 1, a generator set 2, a regenerator assembly 3, a main heater 4, a diverter 5, a precooler 6 and a reheater 7 arranged in the circulation pipeline 100. The regenerator assembly 3 includes a high-temperature regenerator 31, a low-temperature regenerator 32 and a mixer 33. The driving unit 1 includes a starter 11 and a driving turbine 12 and a main compressor 13 driven by the starter 11. The generator set 2 includes an initiator 21 and a power generation turbine 22 and a recompressor 23 connected to the initiator 21.

[0043] Among them, the two outlets of the splitter 5 are respectively connected to the inlet of the main compressor 13 and the inlet of the recompressor 23, a precooler 6 is arranged between the splitter 5 and the main compressor 13, and a first regulating valve 101 is arranged between the splitter 5 and the recompressor 23. The outlet of the main compressor 13 is connected to the cold source side inlet of the low-temperature regenerator 32, and the cold source side outlet of the low-temperature regenerator 32 and the outlet of the recompressor 23 are respectively connected to the two inlets of the mixer 33. The outlet of the mixer 33 is connected to the cold source side inlet of the high-temperature regenerator 31, and the cold source side outlet of the high-temperature regenerator 31 is connected to the inlet of the main heater 4, and the outlet of the main heater 4 is connected to the inlet of the driving turbine 12.

[0044] The outlet of the driving turbine 12 is divided into a first branch and a second branch, the first branch is connected to the inlet of the power generation turbine 22, and the second branch is connected to the heat source side inlet of the high temperature regenerator 31. The first branch is provided with a second regulating valve 102 and a reheater 7 in sequence, and the second branch is provided with a third regulating valve 103. The outlet of the power generation turbine 22 is connected to the heat source side inlet of the high temperature regenerator 31, the heat source side outlet of the high temperature regenerator 31 is connected to the heat source side inlet of the low temperature regenerator 32, and the heat source side outlet of the low temperature regenerator 32 is connected to the inlet of the diverter 5. When working, the supercritical carbon dioxide working medium is filled into various places of the circulation pipeline 100.

[0045] It should be noted that the function of the driving unit 1 is to provide the generator set 2 with high-pressure, high-temperature supercritical carbon dioxide circulating working fluid, and the starter 11 is used to start the rotation of the driving turbine 12 and the main compressor 13 at the initial stage. The function of the generator set 2 is to convert the total enthalpy of the high-pressure, high-temperature supercritical carbon dioxide circulating working fluid into electrical energy, that is, the starter 21 is used to convert the mechanical energy of the power turbine 22 into electrical energy. The precooler 6 is used to reduce the temperature of the working fluid entering the main compressor 13.

[0046] The working principle of the supercritical carbon dioxide cycle power generation system of this embodiment is as follows.

[0047] Before the system is operated, supercritical carbon dioxide (hereinafter referred to as super-II) is charged into various places of the circulation pipeline 100. The starter 11 of the drive unit 1 drives the drive turbine 12 and the main compressor 13 to rotate, and a part of the super-II is compressed in the main compressor 13, and then flows along the system pipeline, passes through the cold source side of the low-temperature regenerator 32 to absorb heat, and is mixed with the super-II at the outlet of the recompressor 23 through the mixer 33, and then enters the cold source side of the high-temperature regenerator 31 to absorb heat, and then enters the main heater 4.

[0048] After that, the super-two working fluid absorbs heat from the main heater 4 and enters the driving turbine 12 for expansion, driving the main compressor 13 to increase speed. After the expanded super-two working fluid is divided by the second regulating valve 102 and the third regulating valve 103, a part of the super-two working fluid enters the reheater 10 through the second regulating valve 102 for further temperature increase, and then enters the power turbine 22 for expansion and work (i.e., power generation), while driving the re-compressor 23 to rotate. The other part of the working fluid enters the heat source side of the high-temperature regenerator 31 and the heat source side of the low-temperature regenerator 32 for heat recovery after the working fluid expands in the power turbine 22 through the third regulating valve 103.

[0049] Afterwards, the working fluid on the heat source side of the low-temperature regenerator 32 flows to the splitter 5 and is divided into two paths. One path enters the precooler 6 to reduce the working fluid temperature to near the critical point and then is compressed at the main compressor 13. The other path of working fluid enters the re-compressor 23 for compression, and a new power generation cycle is restarted.

[0050] When the system needs to reduce the power generation, the flow of the super-two working fluid in the power turbine 22 is reduced by reducing the opening of the second regulating valve 102 and increasing the opening of the third regulating valve 103. At the same time, the opening of the first regulating valve 101 is increased to increase the flow in the re-compressor 23. In this way, the power output of the power turbine 22 can be reduced, and the power consumption of the re-compressor 23 can be increased, thereby quickly reducing the power generation and reducing the power generated by the all-in-one machine 21. On the other hand, the increased flow of the re-compressor 23 will reduce the flow in the main compressor 13, reduce power consumption, and increase the speed of the driving unit 1 due to the reduced power consumption of the main compressor 13, so that the balance state of the whole system can still be guaranteed. At the same time, the inlet pressure of the main compressor 13 will increase because the super-two working fluid has not been fully expanded by the power turbine 22, so it is not easy to enter the two-phase region, thereby ensuring the stable operation of the driving unit 1 and the generator set 2.

[0051] When the cycle needs to increase the power generation, the flow of the super-two working fluid in the power turbine 22 can be increased by increasing the opening of the second regulating valve 102 and decreasing the opening of the third regulating valve 103. At the same time, the opening of the first regulating valve 101 is decreased to reduce the flow in the re-compressor 23. In this way, the power output of the power turbine 22 can be increased and the power consumption of the re-compressor 23 can be reduced, thereby quickly increasing the power generation and increasing the electric energy generated by the all-in-one machine 21. On the other hand, the reduced flow of the generator set 2 will increase the flow of the main compressor 13 in the drive unit 1, increase the power consumption, and reduce the speed of the drive unit 1, so that the balance state of the entire system can still be guaranteed. At the same time, although the inlet pressure of the main compressor 13 will be reduced, it is still higher than the design point pressure, so it is not easy to enter the two-phase region, thereby ensuring the stable operation of the drive unit 1 and the generator set 2.

[0052] In summary, the supercritical carbon dioxide cycle power generation system of this embodiment includes a driving unit 1 and a generator unit 2, forming a split-axis layout, which mechanically decouples the complex super-two systems, thereby increasing the number of adjustable parameters and making the operating conditions more flexible.

[0053] The supercritical carbon dioxide cycle power generation system of this embodiment does not need to discharge the super-two working fluid in the system (i.e., it does not need to use the variable volume method) when operating under variable working conditions (changing the power generation), but relies on adjusting the opening of the first, second, and third regulating valves to achieve the change of the output power of the driving turbine 12 and the power generation turbine 22, rather than simply reducing or increasing the system pressure. The speed of the generator set 2 is generally a constant speed, and the speed of the driving unit 1 is adjustable. The increased or decreased power generation is flexibly adjusted by the driving unit 1 to adapt to and cooperate with the demand for variable power. In the process of power adjustment, the system can still ensure the operating stability and high efficiency without discharging or increasing the super-two working fluid in the system.

[0054] For example, compared with the existing technology, when reducing the power generation capacity, the conventional variable volume method discharges the super-two working fluid in the system to reduce the system pressure, thereby reducing the power generation capacity. The pressure reduction means that the compressor inlet is close to or even reaches the critical point, which brings unpredictable system stability problems.

[0055] When the supercritical carbon dioxide cycle power generation system of the present embodiment is operating at a reduced power, there is no need to discharge the supercritical carbon dioxide in the system (i.e., there is no need to adopt the variable volume method), but instead relies on adjusting the openings of the first, second, and third regulating valves to achieve changes in the output power of the driving turbine 12 and the power generation turbine 22, rather than simply reducing the system pressure. Therefore, the inlet condition of the main compressor 13 will not reach the critical point, but will only remain relatively close to the critical point, so that the power generation power regulation of the present system can overcome the influence of the critical point of supercritical carbon dioxide, thereby being able to ensure the operating stability and high efficiency of the system during the power regulation process.

[0056] In this embodiment, if Figure 1 As shown, the supercritical carbon dioxide circulation power generation system can also include a storage tank 8, which stores carbon dioxide working fluid, and the storage tank 8 is connected to the circulation pipeline 100 from the low-temperature regenerator 32 to the inlet of the diverter 5. When the system starts working, the stored carbon dioxide working fluid (generally supercritical carbon dioxide working fluid) in the storage tank 8 is filled into various parts of the circulation pipeline 100. In order to facilitate the charging and discharge of supercritical carbon dioxide working fluid in the circulation pipeline 100, the inlet of the storage tank 8 is connected to the circulation pipeline 100 through an inlet valve 81, and the outlet of the storage tank 8 is connected to the circulation pipeline 100 through an outlet valve 82. It should be noted that during the circulation operation, the storage tank 8 and the circulation pipeline 100 are generally kept disconnected. In addition, the storage tank 8 can be equipped with a booster device, which is used to increase the carbon dioxide working fluid pressure of the outlet valve 82.

[0057] In this embodiment, if Figure 2 As shown, the first regulating valve 101, the second regulating valve 102 and the third regulating valve 103 can be electric regulating valves. In addition, the supercritical carbon dioxide cycle power generation system can also include a main control device 200, which is at least connected to the first regulating valve 101, the second regulating valve 102 and the third regulating valve 103 for regulating the valve opening.

[0058] In this embodiment, if Figure 2As shown, the main control device 200 can be connected to the main heater 4 and the reheater 7 in communication to control the heating power of the main heater 4 and the reheater 7. At the same time, a working fluid temperature detection sensor or a pressure detection sensor can be set at the main heater 4, the reheater 7 or other required positions of the circulation pipeline 100, and connected to the main control device 200. The main control device 200 compares the value of the working fluid temperature detection sensor and / or the pressure detection sensor with the expected value, and then adjusts the heating power of the main heater 4 and the reheater 7.

[0059] In addition, the main control device 200 can be communicatively connected with the precooler 6, and an inlet temperature detection sensor or an inlet pressure detection sensor can be set between the precooler 6 and the inlet of the main compressor 13. The main control device 200 can adjust the cooling power of the precooler 6 according to the value of the inlet temperature detection sensor or the inlet pressure detection sensor so that the inlet condition of the main compressor 13 will not reach the critical point.

[0060] In this embodiment, if Figure 2 As shown, a pressure detection sensor 300 can be provided at the outlet of the driving turbine 12 . The pressure detection sensor 300 is in communication connection with the main control device 200 . The main control device 200 adjusts the heating power of the main heater 4 according to the pressure information of the pressure detection sensor 300 .

[0061] like Figure 3 As shown, the embodiment of the present application also provides a power regulation method based on the aforementioned supercritical carbon dioxide cycle power generation system, comprising:

[0062] S1. Determine the real-time power generation W before adjusting the power m ;

[0063] S2. Determine the adjusted target power generation W t ;

[0064] S3, based on the target power generation W t The real-time power generation before adjustment W m The opening sizes of the first regulating valve 101, the second regulating valve 102 and the third regulating valve 103 are adjusted according to the size difference.

[0065] In step S1, some power detection sensors can be added to the generator set 2 to determine the real-time power W before adjusting the power. m , or can be obtained by manual measurement. In step S2, the target power generation W t It is the expected value of the generated power after the power needs to be reduced or increased, which is determined according to the actual situation.

[0066] In this embodiment, in step S3, based on the target power generation Wt The real-time power generation before adjustment W m The step of adjusting the opening sizes of the first regulating valve 101, the second regulating valve 102 and the third regulating valve 103 may include:

[0067] S31, determine the target power generation W t The real-time power generation before adjustment W m The power difference W t-m ;

[0068] S32, determine the power difference W t-m is the absolute value of is less than or equal to the first preset difference; if so, proceed to step S33; if not, proceed to step S34;

[0069] S33, keeping the current opening sizes of the first regulating valve 101, the second regulating valve 102 and the third regulating valve 103 unchanged;

[0070] S34, determine the target power generation W t Whether it is less than the real-time power generation W before adjustment m ; If W t Less than W m , then go to step S35; if W t Greater than W m , then proceed to step S36;

[0071] S35, W t Less than W m , that is, it is necessary to reduce the power generation, and according to the preset unit opening amount, the opening of the second regulating valve 102 is reduced, the opening of the third regulating valve 103 is increased, and the opening of the first regulating valve 101 is increased;

[0072] S36, W t Greater than W m , that is, the power generation needs to be increased, the opening of the second regulating valve 102 is increased according to the preset unit opening amount, the opening of the third regulating valve 103 is decreased, and the opening of the first regulating valve 101 is decreased;

[0073] S37, determine the adjusted real-time power generation W a , and determine the adjusted real-time power generation W a and target power generation W t Is the absolute value of the difference less than or equal to the second preset difference; if so, complete the opening adjustment of the first regulating valve 101, the second regulating valve 102 and the third regulating valve 103; if not, repeat steps S35 to S37, or repeat steps S36 to S37.

[0074] It should be noted that the first preset difference is determined according to the actual reduction or increase of the power generation. Since it may be difficult to achieve exactly the same value for power regulation, this value represents the adjusted target power generation W. t The real-time power generation before adjustment W m The permissible consistency error range. Target power generation W t The real-time power generation before adjustment W m The absolute value of the difference does not exceed the first preset difference, indicating that power adjustment is not required. t The real-time power generation before adjustment W m The absolute value of the difference exceeds the first preset difference, indicating that power adjustment is required.

[0075] In addition, it should be noted that the second preset difference is similar to the first preset difference, because the real-time power generation W after the final adjustment is a It may be difficult to achieve the target power generation W t The values ​​are exactly the same, so this value represents the adjusted real-time power generation W a and target power generation W t The permissible consistency error range. Target power generation W t The adjusted real-time power generation W a The absolute value of the difference does not exceed the second preset difference, indicating that the power adjustment is completed. t The adjusted real-time power generation W a The absolute value of the difference exceeds the second preset difference, indicating that the power adjustment has not been completed and needs to be further adjusted.

[0076] The preset unit opening amount in step S35 and step S36 can be set according to the actual structure of the valve and the actual adjustment requirements, but it should be noted that the value of the preset unit opening amount should not be too large, so as to avoid excessive adjustment and excessive power adjustment.

[0077] In this embodiment, before step S3, the following steps may be included: S03, obtaining the outlet pressure P of the driving turbine 12 before the regulating valve is adjusted. 0 After step S3, the method further includes:

[0078] S4. Obtain the outlet pressure P of the driving turbine 12 after adjustment by the regulating valve t ;

[0079] S5. Determine the outlet pressure P t With outlet pressure P 0Is the absolute value of the difference between the pressure difference and the pressure difference less than or equal to the preset pressure difference? If so, keep the current heating power of the main heater 4 unchanged; if not, adjust the heating power of the main heater 4, and repeat steps S4 to S5 until the outlet pressure P t With outlet pressure P 0 The difference is controlled within a predetermined range.

[0080] For example, when reducing the power generation, the increased flow rate of the compressor 23 will reduce the flow rate in the main compressor 13, reduce power consumption, and increase the speed of the driving unit 1 (the inlet temperature of the driving turbine 12 remains basically unchanged) due to the increase in the flow rate of the super-second working fluid in the main compressor 13, so it is still in a balanced state. In addition, the heat control can be added through the main heater 4 to control the overall speed of the driving unit 1 and maintain the outlet pressure of the driving turbine 12 unchanged.

[0081] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A supercritical carbon dioxide cycle power generation system, characterized in that: The invention comprises a circulation pipeline (100) and a driving unit (1), a generator unit (2), a regenerator assembly (3), a main heater (4), a flow divider (5), a precooler (6) and a reheater (7) arranged in the circulation pipeline (100); The regenerator assembly (3) comprises a high-temperature regenerator (31), a low-temperature regenerator (32) and a flow mixer (33); The driving unit (1) comprises a starter (11) and a driving turbine (12) and a main compressor (13) driven by the starter (11); The generator set (2) comprises an all-in-one engine (21), a power generation turbine (22) and a re-compressor (23) drivingly connected to the all-in-one engine (21); The two outlets of the flow divider (5) are respectively connected to the inlet of the main compressor (13) and the inlet of the re-compressor (23); the pre-cooler (6) is arranged between the flow divider (5) and the main compressor (13); and the first regulating valve (101) is arranged between the flow divider (5) and the re-compressor (23); The outlet of the main compressor (13) is connected to the inlet of the cold source side of the low-temperature regenerator (32), and the outlet of the cold source side of the low-temperature regenerator (32) and the outlet of the recompressor (23) are respectively connected to the two inlets of the mixer (33); the outlet of the mixer (33) is connected to the inlet of the cold source side of the high-temperature regenerator (31), and the outlet of the cold source side of the high-temperature regenerator (31) is connected to the inlet of the main heater (4), and the outlet of the main heater (4) is connected to the inlet of the driving turbine (12); The outlet of the driving turbine (12) is divided into a first branch and a second branch, the first branch is connected to the inlet of the power generation turbine (22), the second branch is connected to the heat source side inlet of the high-temperature regenerator (31), a second regulating valve (102) and the reheater (7) are arranged in sequence on the first branch, and a third regulating valve (103) is arranged on the second branch; The outlet of the power generation turbine (22) is connected to the heat source side inlet of the high-temperature heat regenerator (31), the heat source side outlet of the high-temperature heat regenerator (31) is connected to the heat source side inlet of the low-temperature heat regenerator (32), and the heat source side outlet of the low-temperature heat regenerator (32) is connected to the inlet of the diverter (5); During operation, supercritical carbon dioxide working fluid is filled into various locations of the circulation pipeline (100).

2. The supercritical carbon dioxide cycle power generation system according to claim 1, characterized in that: It comprises a storage tank (8) storing carbon dioxide as a working medium, and the storage tank (8) is connected to the circulation pipeline (100) between the low-temperature regenerator (32) and the inlet of the diverter (5).

3. The supercritical carbon dioxide cycle power generation system according to claim 2, characterized in that: The inlet of the storage tank (8) is connected to the circulation pipeline (100) through an inlet valve (81), and the outlet of the storage tank (8) is connected to the circulation pipeline (100) through an outlet valve (82).

4. The supercritical carbon dioxide cycle power generation system according to claim 3, characterized in that: A pressure boosting device is provided in the storage tank (8), and the pressure boosting device is used to increase the pressure of the carbon dioxide working medium of the outlet valve (82).

5. The supercritical carbon dioxide cycle power generation system according to claim 1, characterized in that: The first regulating valve (101), the second regulating valve (102) and the third regulating valve (103) are electric regulating valves; The supercritical carbon dioxide cycle power generation system comprises a main control device (200), wherein the main control device (200) is at least in communication connection with the first regulating valve (101), the second regulating valve (102) and the third regulating valve (103) for adjusting valve openings.

6. The supercritical carbon dioxide cycle power generation system according to claim 5, characterized in that: The main control device (200) is connected in communication with the main heater (4) and the reheater (7) to control the heating power of the main heater (4) and the reheater (7).

7. The supercritical carbon dioxide cycle power generation system according to claim 6, characterized in that: A pressure detection sensor (300) is provided at the outlet of the driving turbine (12), and the pressure detection sensor (300) is communicatively connected with the main control device (200). The main control device (200) regulates the heating power of the main heater (4) according to the pressure information of the pressure detection sensor (300).

8. A power regulation method based on the supercritical carbon dioxide cycle power generation system according to any one of claims 1 to 7, characterized in that: include: S1. Determine the real-time power generation W before adjusting the power m ; S2. Determine the adjusted target power generation W t ; S3, based on the target power generation W t The real-time power generation before adjustment W m The opening sizes of the first regulating valve (101), the second regulating valve (102) and the third regulating valve (103) are adjusted according to the size differences.

9. The power regulation method according to claim 8, characterized in that: In step S3, based on the target power generation W t The real-time power generation before adjustment W m The step of adjusting the opening sizes of the first regulating valve (101), the second regulating valve (102) and the third regulating valve (103) according to the size difference of the first regulating valve (101), the second regulating valve (102) and the third regulating valve (103) comprises: S31, determine the target power generation W t The real-time power generation before adjustment W m The power difference W t-m ; S32, determine the power difference W t-m Is the absolute value of is less than or equal to the first preset difference; if so, proceed to step S33; if not, proceed to step S34; S33, maintaining the current opening sizes of the first regulating valve (101), the second regulating valve (102) and the third regulating valve (103) unchanged; S34, determine the target power generation W t Whether it is less than the real-time power generation W before adjustment m ; If W t Less than W m , then go to step S35; if W t Greater than W m , then proceed to step S36; S35, reducing the opening of the second regulating valve (102), increasing the opening of the third regulating valve (103), and increasing the opening of the first regulating valve (101) according to a preset unit opening amount; S36, increasing the opening of the second regulating valve (102), decreasing the opening of the third regulating valve (103), and decreasing the opening of the first regulating valve (101) according to a preset unit opening amount; S37, determine the adjusted real-time power generation W a , and determine the adjusted real-time power generation W a and target power generation W t is less than or equal to a second preset difference; if so, the opening adjustment of the first regulating valve (101), the second regulating valve (102) and the third regulating valve (103) is completed; if not, steps S35 to S37 are repeated, or steps S36 to S37 are repeated.

10. The power regulation method according to claim 8, characterized in that: Before step S3, the method further includes: S03, obtaining the outlet pressure P0 of the driving turbine (12) before the regulating valve is adjusted; After step S3, the method further includes: S4. Obtain the outlet pressure P of the driving turbine (12) after adjustment by the regulating valve t ; S5. Determine the outlet pressure P t Whether the absolute value of the difference between the outlet pressure P0 and the pressure at the outlet is less than or equal to the preset pressure difference; if so, the current heating power of the main heater (4) is kept unchanged; if not, the heating power of the main heater (4) is adjusted, and steps S4 to S5 are repeated until the outlet pressure P t The difference with the outlet pressure P0 is controlled within a predetermined difference range.

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