Coal-based poly-generation flexible variable load system and operation method thereof

Abstract

The present application relates to the technical field of power generation system, in particular to a coal-based poly-generation flexible variable load system and its operation method. The system comprises: a power generation subsystem, which comprises a steam generator, a steam turbine unit, a condenser and a regenerative component in circulation communication, the fluid outlet of the regenerative component is in communication with the fluid inlet of the steam generator, and a steam extraction pipeline is in communication between the steam turbine unit and the regenerative component; a heat exchange subsystem, which comprises a compressor, a heat supply heat exchanger, a turbine and a cold supply heat exchanger in circulation communication, the outlet of the cold supply heat exchanger is in communication with the inlet end of the compressor; a heat storage component, whose first flow passage is in communication between the steam turbine unit and the regenerative component, and whose second flow passage is in communication between the compressor and the heat supply heat exchanger. The present application determines the operation power of the heat exchange subsystem based on the cold load, cooperates with heat storage to carry out multi-load regulation and control, is not limited by the heat load, can greatly improve the flexibility of the poly-generation system, and the regulation and control speed and range of the power generation system in the process of increasing and decreasing the load.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power generation systems, in particular to a coal-based multi-generation flexible variable load system and an operation method thereof. BACKGROUND

[0002] Energy shortage, climate change and environmental pollution are increasingly serious, which poses new challenges to the development of power systems. China will also accelerate the construction of a new power system dominated by new energy. However, coal-fired power generation will continue to play an important role in ensuring the safe operation of the power grid, meeting the basic energy needs of society and promoting the consumption of new energy. The construction of a new power system poses new technical requirements for traditional thermal power units: continuously improving energy efficiency to reduce carbon emissions; continuously improving operational flexibility to support the consumption of new energy by the power grid.

[0003] Multi-energy supply is an effective way to achieve energy cascade utilization and improve the efficiency of coal-fired units. However, the variable load capacity of multi-generation units in the prior art is limited by the flow coupling of the boiler-turbine and the multi-output energy flow coupling, and the operational flexibility is insufficient, resulting in a decrease in the adjustable range of the electrical load of the power generation system as the thermal load increases. SUMMARY

[0004] Therefore, the technical problem to be solved by the present application is to overcome the insufficient operational flexibility of the multi-generation system in the prior art, thereby providing a coal-based multi-generation flexible variable load system and an operation method thereof.

[0005] To solve the above technical problems, the present application provides a coal-based multi-generation flexible variable load system, comprising:

[0006] A power generation system comprising a steam generator, a turbine unit, a condenser and a regenerative component in circulation communication, the fluid outlet of the regenerative component being in communication with the fluid inlet of the steam generator, and an extraction pipe being in communication between the turbine unit and the regenerative component;

[0007] A heat exchange subsystem comprising a compressor, a heat supply heat exchanger, a turbine and a cold supply heat exchanger in circulation communication, the outlet of the cold supply heat exchanger being in communication with the inlet end of the compressor;

[0008] A regenerative component, a first flow passage of which is in communication between the turbine unit and the regenerative component, and a second flow passage of which is in communication between the compressor and the heat supply heat exchanger, and a regenerative element being installed in the regenerative component to store heat.

[0009] The heat exchange subsystem further comprises an auxiliary regenerator, a first flow passage of which is in communication between the heat supply heat exchanger and the turbine, and a second flow passage of which is in communication between the cold supply heat exchanger and the compressor.

[0010] The heat exchange sub-system further comprises an auxiliary heat exchanger, a first flow channel of the auxiliary heat exchanger being communicated between the cold supply heat exchanger and the compressor, and a second flow channel of the auxiliary heat exchanger being communicated with the cooling water flow channel of the condenser.

[0011] Optionally, a cooling water supplement branch is communicated on an inlet side pipeline of the cooling water flow channel of the condenser, and a cooling water output branch is communicated on an outlet side pipeline of the cooling water flow channel of the condenser.

[0012] Optionally, a power generation device is coaxially installed on the steam turbine unit.

[0013] Optionally, the power generation device is electrically connected between the compressor.

[0014] Optionally, the heat supply heat exchanger is connected with a heat supply network.

[0015] Optionally, the cold supply heat exchanger is connected with a cold supply device.

[0016] The application further provides a running method of the multi-product system, which is applied to the coal-based multi-product flexible variable load system and comprises the following steps:

[0017] According to the cold load demand of the cold supply heat exchanger, the running power of the heat exchange sub-system is determined.

[0018] It is judged whether the heating power of the heat exchange sub-system is greater than the heat load demand of the heat supply heat exchanger, if yes, the heat storage component is controlled to store heat, if no, the heat storage component is controlled to release heat to the heat supply heat exchanger, and if only the heat load needs to be adjusted, the step is directly performed.

[0019] It is judged whether the running load of the power generation sub-system is greater than the demand load, if yes, the steam extraction amount of the steam turbine unit to the heat storage component is increased, if no, the heat storage component is controlled to release heat to the heat recovery component, and if only the electric load needs to be adjusted, the step is directly performed.

[0020] Optionally, the heat storage step of the heat storage component comprises: increasing the flow of the heat exchange medium from the compressor to the heat storage component, and reducing the flow of the heat exchange medium from the compressor to the heat supply heat exchanger, so as to increase the heat storage rate of the heat storage component, and meanwhile keep the steam output rate and the heat energy of the heat supply heat exchanger constant.

[0021] The technical scheme has the following advantages:

[0022] 1. The coal-based poly-generation flexible variable load system provided by the present application comprises: a power generation subsystem comprising a steam generator, a steam turbine unit, a condenser and a regenerative component in circulation communication, a fluid outlet of the regenerative component being in communication with a fluid inlet of the steam generator, and a steam extraction pipeline being in communication between the steam turbine unit and the regenerative component; a heat exchange subsystem comprising a compressor, a heat supply heat exchanger, a turbine and a heat removal heat exchanger in circulation communication, an outlet of the heat removal heat exchanger being in communication with an inlet end of the compressor; and a heat storage component, a first flow passage of which being in communication between the steam turbine unit and the regenerative component, and a second flow passage of which being in communication between the compressor and the heat supply heat exchanger, and a heat storage element being installed in the heat storage component to store heat.

[0023] By coupling the heat exchange subsystem to the steam power generation subsystem, the heat supply heat exchanger and the heat removal heat exchanger can supply heat and remove heat to and from a user terminal outside the system, thereby meeting the energy form requirements of the external user terminal and greatly improving the primary energy utilization rate.

[0024] During system operation, the running power of the heat exchange subsystem is determined based on the cold load, and the heat load of the unit is regulated and controlled by the heat storage component. Specifically, when the external cold load requirement changes, the running power of the heat exchange subsystem is changed based on the load of the heat removal heat exchanger to meet the external cold load requirement; at this time, the corresponding heating power of the heat exchange subsystem changes, and the heating power and the heat load requirement of the heat supply heat exchanger are judged, and the output heat load is regulated and controlled by the heat storage component to balance the external requirement. If only the heat load requirement changes, the heat storage component can be used for regulation and control. When the electric load is adjusted, whether the power output of the power generation subsystem changes due to the change of the power of the heat exchange subsystem or the external electric load changes, when the power generation subsystem needs to be upgraded for peak regulation, the heat storage component releases heat to the regenerative component to replace the steam extraction, thereby reducing the steam extraction amount of the steam turbine unit and realizing the rapid upgrade of the power generation system for peak regulation; when the power generation subsystem needs to be downgraded for peak regulation, the steam extraction amount of the steam turbine unit is increased, and the excess steam is delivered to the heat storage component to store heat, thereby realizing the rapid downgrading for peak regulation.

[0025] The coal-based poly-generation flexible variable load system realizes multi-strategy regulation and control under multiple load changes, can simultaneously meet the peak regulation requirements of the power generation system and the cold and heat requirements of the cold and heat users, improves the flexibility of system operation, reduces the cold and heat load limitations, and can greatly improve the peak regulation rate and range of the power generation system for upgrade and downgrading for peak regulation.

[0026] 2. The coal-based poly-generation flexible variable load system provided by the present application, the heat exchange subsystem further comprises an auxiliary regenerator, a first flow channel of the auxiliary regenerator is connected between the heat supply heat exchanger and the turbine, and a second flow channel of the auxiliary regenerator is connected between the cold supply heat exchanger and the compressor. By arranging the auxiliary regenerator in the heat exchange subsystem, the pipeline at the outlet end of the heat supply heat exchanger and the pipeline at the outlet end of the cold supply heat exchanger are matched for heat exchange by means of the auxiliary regenerator, the low-temperature heat at the outlet end of the heat supply heat exchanger is fully utilized, and the efficiency of the heat exchange subsystem is improved.

[0027] 3. The coal-based poly-generation flexible variable load system provided by the present application, the heat exchange subsystem further comprises an auxiliary heat exchanger, a first flow channel of the auxiliary heat exchanger is connected between the cold supply heat exchanger and the compressor, and a second flow channel of the auxiliary heat exchanger is connected with a cooling water flow channel of the condenser. By arranging the auxiliary heat exchanger and the condenser in the power generation subsystem, the waste heat at the cold end of the power generation subsystem is deeply recovered, and the overall operation efficiency of the system is improved.

[0028] 4. The coal-based poly-generation flexible variable load system provided by the present application, a cooling water supplement branch is connected to the inlet side pipeline of the cooling water flow channel of the condenser, and a cooling water output branch is connected to the outlet side pipeline of the cooling water flow channel of the condenser. By arranging the cooling water supplement branch and the cooling water output branch, when the cooling capacity provided by the auxiliary heat exchanger is insufficient, cooling water is introduced from outside the system through the cooling water supplement branch, and the warmed cooling water is discharged from the cooling water output branch, so as to maintain the normal operation of the condenser. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the specific embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0030] Figure 1 The schematic diagram of the coal-based poly-generation flexible variable load system provided in the embodiments of the present application.

[0031] The drawings are explained as follows: 1, steam generator; 2, steam turbine unit; 3, regenerative component; 4, condenser; 5, generator; 6, compressor; 7, heat storage component; 8, auxiliary regenerator; 9, heat supply heat exchanger; 10, turbine; 11, cold supply heat exchanger; 12, heat supply network; 13, cold supply equipment; 14, auxiliary heat exchanger. DETAILED DESCRIPTION

[0032] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0033] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0034] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0035] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0036] Embodiment 1

[0037] As Figure 1 The coal-based multi-production flexible variable load system provided in the embodiment is shown, which comprises a power generation subsystem, a heat exchange subsystem and a heat storage packed bed as a heat storage component 7.

[0038] The power generation subsystem comprises a circulatingly connected coal-fired boiler as a steam generator 1, a steam turbine unit 2, a condenser 4 and a regenerative component 3. The fluid outlet of the regenerative component 3 is in communication with the fluid inlet of the steam generator 1, and a steam extraction pipeline is in communication between the steam turbine unit 2 and the regenerative component 3. The steam generator 1 can also be a heating device for burning natural gas, coal gas and other fossil energy to generate heat.

[0039] The heat exchange subsystem comprises a compressor 6, a heat supply heat exchanger 9, a turbine 10 and a heat removal heat exchanger 11 in circulation connection, and the outlet of the heat removal heat exchanger 11 is connected with the inlet of the compressor 6. The heat exchange subsystem further comprises an auxiliary regenerator 8 and an auxiliary heat exchanger 14, the first flow passage of the auxiliary regenerator 8 is connected between the heat supply heat exchanger 9 and the turbine 10, and the second flow passage of the auxiliary regenerator 8 is connected between the heat removal heat exchanger 11 and the compressor 6. The first flow passage of the auxiliary heat exchanger 14 is connected between the heat removal heat exchanger 11 and the compressor 6, and the second flow passage of the auxiliary heat exchanger 14 is connected with the cooling water flow passage of the condenser 4. The cooling water flow passage of the condenser 4 is connected with a cooling water supplement branch on the inlet side, and is connected with a cooling water output branch on the outlet side.

[0040] The first flow passage of the heat storage assembly 7 is connected between the turbine unit 2 and the regenerator assembly 3, and the second flow passage of the heat storage assembly 7 is connected between the compressor 6 and the heat supply heat exchanger 9, and the heat storage assembly 7 is provided with a heat storage member for storing heat.

[0041] The turbine unit 2 is coaxially provided with a generator 5 as a power generation device. The power generation device is electrically connected with the compressor 6 to drive the compressor 6 to operate, and the excess power generated by the power generation device is transmitted to the power grid. The heat supply heat exchanger 9 is connected with a heat supply network 12 for supplying heat to the heat supply network 12. The heat removal heat exchanger 11 is connected with a heat removal device 13 such as a central air conditioner for supplying cold to a user end.

[0042] The heat storage end of the heat storage assembly is connected with the outlet of the compressor 6 and the steam extraction pipeline of the turbine unit 2 respectively, and the heat release end of the heat storage assembly 7 is connected with the heat end of the regenerator assembly 3 and the heat supply heat exchanger 9 respectively. In the embodiment, the circulating working medium of the heat exchange subsystem is carbon dioxide, the inlet pressure of the compressor 6 is 1.5-3.5 MPa, and the outlet pressure is 17-20 MPa. The circulating medium in the heat exchange subsystem can also be compressed air and other fluids.

[0043] By coupling the heat exchange subsystem to the steam power generation system, the heat supply heat exchanger 9 and the heat removal heat exchanger 11 supply heat and remove heat to the user end outside the system. When the poly-generation system is running, the refrigeration cycle power is determined based on the cold load, the heat load of the linkage system is determined, and the peak shaving of the electric load of the unit is performed in cooperation with the heat storage assembly 7.

[0044] When the poly-generation system adjusts the cold load, the carbon dioxide circulating working fluid flow of the heat exchange subsystem is increased or decreased to achieve this, and the heat exchange subsystem is linked to the heat load; when the heat load is adjusted, if the heat load is reduced, the flow of the heat exchange medium from the compressor 6 to the heat storage assembly 7 is increased, and the flow of the heat exchange medium from the compressor 6 to the heat supply heat exchanger 9 is reduced; if the heat load is increased, the stored heat of the heat storage assembly 7 is released and is passed to the heat supply heat exchanger 9. When the power generation system adjusts the electric load, the steam extraction amount of the steam turbine set 2 is increased to store the excess steam heat in the heat storage assembly 7, or the heat of the heat storage assembly 7 is released to replace the steam extraction, so that the load can be quickly increased or decreased. The coal-based poly-generation flexible variable load system realizes multi-strategy regulation and control of the poly-generation system when the load is adjusted, can simultaneously meet the peak shaving demand of the power generation system and the cold and heat demand of the cold and heat users, improves the flexibility of system operation, is not limited by the cold and heat loads of the system, and can greatly provide the peak shaving range of the power generation system when the load is increased or decreased.

[0045] Embodiment 2

[0046] The present application also provides a coal-based poly-generation flexible variable load system operation method, which is applied to the coal-based poly-generation flexible variable load system in Embodiment 1 and includes the following steps.

[0047] Firstly, the operation power of the heat exchange subsystem is determined according to the external cold load demand, that is, whether the refrigeration power of the heat exchange subsystem is greater than the external cold load demand is determined, if yes, the circulating working fluid flow of the heat exchange subsystem is reduced, and if no, the circulating working fluid flow of the heat exchange subsystem is increased.

[0048] Then, whether the power of the heat supply heat exchanger 9 in the heat exchange subsystem is greater than the external heat load demand is determined, if yes, the heat storage assembly 7 is controlled to store heat, and if no, the heat storage assembly 7 is controlled to release heat to the heat supply heat exchanger 9.

[0049] Further, whether the operation load of the power generation system is greater than the demand load is determined, if yes, the load needs to be reduced, and the steam extraction amount of the steam turbine set 2 to the heat storage assembly 7 is increased, and if no, the load needs to be increased, the heat storage assembly 7 is controlled to release heat to the regenerative assembly 3, the heat of the heat storage assembly 7 is released to replace part of the steam extraction of the steam turbine set 2, and the steam extraction amount of the steam turbine set 2 is reduced to improve the load increasing rate of the steam turbine set 2.

[0050] The step of controlling the heat storage assembly 7 to store heat includes increasing the flow of the heat exchange medium from the compressor 6 to the heat storage assembly 7 and reducing the flow of the heat exchange medium from the compressor 6 to the heat supply heat exchanger 9, so that the heat storage rate of the heat storage assembly 7 is increased, and the steam output rate and the heat energy of the heat supply heat exchanger 9 are kept constant.

[0051] The coal-based multi-production flexible variable load system operation method provided in the embodiment realizes the satisfaction of the user end cold energy, heat energy and electric energy demand through the coal-based multi-production flexible variable load system provided in the embodiment 1, the energy in the system can be reused through the coupling of the power generation sub-system and the heat exchange sub-system and the peak regulation of the heat storage component 7, and the utilization rate of the primary energy can be greatly improved. The load regulation strategy provided in the embodiment can realize the multi-energy flow output decoupling, improve the coal-fired generator 5 group variable load rate and improve the coal-based multi-production unit flexibility through the linkage regulation in multiple forms such as changing the compressor 6 operation power, changing the turbine 10 operation power or changing the steam extraction amount of the heat storage component 7 from the steam turbine unit 2.

[0052] Obviously, the above embodiments are only examples for clearly illustrating the present application, and are not intended to limit the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, all the embodiments cannot be exhausted, and the obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A coal-based poly-generation flexible load varying system, characterized in that, The application relates to a coal-based multi-production flexible load system, which comprises the following components: a power generation system, a heat exchange system, a regenerative component, an auxiliary regenerator and an auxiliary heat exchanger. The power generation system comprises a steam generator (1), a steam turbine unit (2), a condenser (4) and the regenerative component (3), the fluid outlet of the regenerative component (3) is communicated with the fluid inlet of the steam generator (1), and a steam extraction pipeline is arranged between the steam turbine unit (2) and the regenerative component (3); The heat exchange system comprises a compressor (6), a heat supply heat exchanger (9), a turbine (10) and a cold supply heat exchanger (11), the outlet of the cold supply heat exchanger (11) is communicated with the inlet end of the compressor (6); The regenerative component (7) is communicated between the steam turbine unit (2) and the regenerative component (3) through a first flow channel, and is communicated between the compressor (6) and the heat supply heat exchanger (9) through a second flow channel, and a regenerative element is arranged in the regenerative component (7) to store heat; The heat exchange system further comprises the auxiliary regenerator (8) and the auxiliary heat exchanger (14), the first flow channel of the auxiliary regenerator (8) is communicated between the heat supply heat exchanger (9) and the turbine (10), the second flow channel of the auxiliary regenerator (8) is communicated between the cold supply heat exchanger (11) and the compressor (6), the first flow channel of the auxiliary heat exchanger (14) is communicated between the cold supply heat exchanger (11) and the auxiliary regenerator (8), and the second flow channel of the auxiliary heat exchanger (14) is communicated with the cooling water flow channel of the condenser (4).

2. The coal-based poly-generation flexible variable load system according to claim 1, characterized in that, A cooling water supplement branch is arranged on the inlet side pipeline of the cooling water flow channel of the condenser (4), and a cooling water output branch is arranged on the outlet side pipeline of the cooling water flow channel of the condenser (4).

3. The coal-based poly-generation flexible load varying system according to claim 1 or 2, characterized in that, An electricity generation device is coaxially arranged on the steam turbine unit (2).

4. The coal-based poly-generation flexible variable load system of claim 3, wherein, The electricity generation device is electrically connected with the compressor (6).

5. The coal-based poly-generation flexible variable load system of claim 3, wherein, The heat supply heat exchanger (9) is connected with a heat network (12).

6. The coal-based poly-generation flexible variable load system of claim 3, wherein, The cold supply heat exchanger (11) is connected with a cold supply device (13).

7. A method of operating a coal-based poly-generation flexible load following system, characterized in that, The application is applied to the coal-based multi-production flexible load system, and comprises the following steps: The operation power of the heat exchange system is determined according to the cold load demand of the cold supply heat exchanger (11); It is judged whether the heating power of the heat exchange system is greater than the heat load demand of the heat supply heat exchanger (9), if yes, the regenerative component (7) is controlled to store heat, if no, the regenerative component (7) is controlled to release heat to the heat supply heat exchanger (9), and if only the heat load needs to be adjusted, the step is directly performed; It is judged whether the operation load of the power generation system is greater than the demand load, if yes, the steam extraction amount of the steam turbine unit (2) to the regenerative component (7) is increased, if no, the regenerative component (7) is controlled to release heat to the regenerative component (3), and if only the electricity load needs to be adjusted, the step is directly performed.

8. The method of claim 7, wherein the coal-based poly-generation flexible load- varying system is operated in a manner that, The step of controlling the regenerative component (7) to store heat comprises the following steps: the flow of the heat exchange medium from the compressor (6) to the regenerative component (7) is increased, and the flow of the heat exchange medium from the compressor (6) to the heat supply heat exchanger (9) is reduced, so that the heat storage rate of the regenerative component (7) is increased, and the output rate and the heat energy of the heat supply heat exchanger (9) are kept constant.

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