Deep peak shaving power station combined with liquid air energy storage and deep peak shaving method

Abstract

The present invention provides a deep peak shaving power station combined with liquid air energy storage and a deep peak shaving method. In this power station, a driving flow path and a heat exchange flow path are bypass-connected between the first steam turbine unit and the regenerator of the power plant unit. The driving flow path and the heat exchange flow path are in parallel and are respectively connected to the energy storage flow path and the energy release flow path of the liquid air energy storage unit; at any stage of the power grid, the first steam turbine unit is used to do work to transmit power to the power grid; during the valley period of power consumption of the power grid, the driving flow path can be used to extract inter-stage steam from the first steam turbine unit to drive the operation of the energy storage flow path; during the peak period of power consumption of the power grid, the heat exchange flow path can be used to extract inter-stage steam from the first steam turbine unit to exchange heat with the medium in the energy release flow path, so as to preheat the medium in the energy release flow path in the energy release power generation state. It can be seen that this power station flexibly adjusts the peak according to the power consumption load stage of the power grid, reduces the energy conversion process, improves the overall operation efficiency of the power station, and reduces the operation cost of the power station.

Description

Technical Field

[0001] The present invention relates to the technical field of energy conservation and environmental protection, and particularly to a deep peak shaving power station combined with liquid air energy storage and a deep peak shaving method. Background Art

[0002] With the rapid progress of global industrialization, the power grid load has periodic changes with peaks during the day and valleys at night, and the peak-valley difference of the electricity load can reach 30% - 40% of the maximum power generation output. The existence of the peak-valley difference causes certain difficulties in power generation and power dispatching, and also brings certain risks to the operation of the power grid. At the same time, in order to meet the maximum load requirements of the power grid, the construction cost of the power grid has increased significantly, and the utilization efficiency is relatively low.

[0003] Currently, among power grid transmission technologies, the peak shaving ratio of thermal power plants is relatively the highest, but limited by the technical characteristics of thermal power plants themselves, the peak shaving ratio is relatively low. When the electricity consumption is at a peak, the units of the peak shaving power plant increase the power generation, and when the electricity consumption is at a valley, the units of the peak shaving power plant reduce the power generation to achieve peak shaving power generation. However, the increase and decrease amplitudes of the power generation of conventional peak shaving thermal power plants cannot be too high, otherwise it will seriously affect the working efficiency of boilers and steam turbine units; moreover, adjusting the power generation power of thermal power units mainly by changing the steam inlet parameters of steam turbine units, and too large a change in parameters will also significantly affect the coal utilization efficiency of boilers and the safety and service life of steam turbine units; at the same time, due to the hysteresis of changing parameters of coal-fired boilers, it will further lead to untimely peak shaving response. Summary of the Invention

[0004] The present invention provides a deep peak shaving power station combined with liquid air energy storage to solve the defects in the prior art that thermal power plants are limited by their own technical characteristics, and too large a peak shaving amplitude will seriously affect the working efficiency, utilization efficiency, safety and service life of boilers and steam turbine units of thermal power plants, and will also lead to untimely peak shaving response.

[0005] The present invention also provides a deep peak shaving method.

[0006] The present invention provides a deep peak shaving power station combined with liquid air energy storage, including:

[0007] A driving flow path, bypass-connected between the first steam turbine unit of the power plant unit and the regenerator, wherein the first steam turbine unit and the regenerator are connected in the same steam circulation flow path;

[0008] A heat exchange flow path, bypass-connected between the first steam turbine unit and the regenerator, and arranged in parallel with the driving flow path;

[0009] Wherein, the first steam turbine unit is used for transmitting power to the power grid;

[0010] When the power grid is in the off-peak period of electricity consumption, the driving flow path can extract inter-stage steam from the first steam turbine unit to drive the operation of the energy storage flow path of the liquid air energy storage unit;

[0011] When the power grid is in the peak period of electricity consumption, the heat exchange flow path can extract inter-stage steam from the first steam turbine unit to exchange heat with the energy release flow path of the liquid air energy storage unit, so as to preheat the medium in the energy release flow path in the energy release power generation state.

[0012] According to a deep peak shaving power station combined with liquid air energy storage provided by the present invention, a second steam turbine unit is provided on the driving flow path. The liquid air energy storage unit includes an air compressor unit and an energy storage tank. The energy storage flow path is connected between the air compressor unit and the energy storage tank. The power output shaft end of the second steam turbine unit is connected to the power input shaft end of the air compressor unit.

[0013] According to a deep peak shaving power station combined with liquid air energy storage provided by the present invention, the liquid air energy storage unit further includes an air turbine unit and an air preheater. The energy release flow path is connected between the energy storage flow path and the air turbine unit; the first heat exchange side of the air preheater is connected to the energy release flow path, and the second heat exchange side of the air preheater is connected to the heat exchange flow path.

[0014] According to a deep peak shaving power station combined with liquid air energy storage provided by the present invention, at least one control valve is respectively provided on the driving flow path and the heat exchange flow path, and each control valve is respectively signal-connected to the power grid.

[0015] According to a deep peak shaving power station combined with liquid air energy storage provided by the present invention, at least one first control valve is provided on the connecting pipeline between the steam inlet end of the second steam turbine unit and the first steam turbine unit; and / or,

[0016] At least one second control valve is provided on the connecting pipeline between the exhaust end of the second steam turbine unit and the regenerator.

[0017] According to a deep peak shaving power station combined with liquid air energy storage provided by the present invention, at least one third control valve is provided on the connecting pipeline between the steam inlet end of the second heat exchange side of the air preheater and the first steam turbine unit; and / or,

[0018] At least one fourth control valve is provided on the connecting pipeline between the exhaust end of the second heat exchange side of the air preheater and the regenerator.

[0019] According to a deep peak shaving power station combined with liquid air energy storage provided by the present invention, the liquid air energy storage unit further includes:

[0020] A compression heat utilization device, wherein its first heat exchange side and second heat exchange side are respectively connected to the energy storage flow path and the energy release flow path;

[0021] A cold accumulator, wherein its first heat exchange side is connected to the energy storage flow path between the compression heat utilization device and the energy storage tank, and the second heat exchange side of the cold accumulator is connected to the energy release flow path between the energy storage tank and the compression heat utilization device;

[0022] A throttling element, connected to the energy storage flow path between the first heat exchange side of the cold accumulator and the energy storage tank;

[0023] A driving pump, connected to the energy release flow path between the energy storage tank and the second heat exchange side of the cold accumulator.

[0024] According to a deep peak shaving power station combined with liquid air energy storage provided by the present invention, the first steam turbine unit is connected with a first generator, the air turbine unit is connected with a second generator, and the first generator and the second generator can each transmit electricity to the power grid through transmission pipelines respectively.

[0025] According to a deep peak shaving power station combined with liquid air energy storage provided by the present invention, the power plant unit includes a steam boiler, a condenser, a first feed water pump and a second feed water pump, and the steam boiler, the first steam turbine unit, the condenser, the first feed water pump, the regenerator and the second feed water pump are sequentially connected in the same steam circulation flow path.

[0026] The present invention also provides a deep peak shaving method, which is executed by the deep peak shaving power station combined with liquid air energy storage as described above; the deep peak shaving method includes:

[0027] The power grid is divided into a flat power consumption section, a valley power consumption section and a peak power consumption section according to the power consumption load;

[0028] When the power grid is in the flat power consumption section, both the driving flow path and the heat exchange flow path are in a closed state, and the power plant unit generates electricity for the power grid by the first steam turbine unit doing work;

[0029] When the power grid is in the valley power consumption section, the power plant unit generates electricity for the power grid by the first steam turbine unit doing work, and the driving flow path is opened to drive the inter-stage steam of the first steam turbine unit to drive the operation of the energy storage flow path of the liquid air energy storage unit;

[0030] When the power grid is in the peak power consumption section, the energy release flow path of the liquid air energy storage unit is driven to generate electricity for the power grid, and the power plant unit is driven to generate electricity for the power grid by the first steam turbine unit doing work, and the heat exchange flow path is opened to drive the inter-stage steam of the first steam turbine unit to exchange heat with the medium in the energy release flow path.

[0031] The present invention provides a deep peak shaving power station combined with liquid air energy storage. In this power station, a driving flow path and a heat exchange flow path are bypass-connected between the first steam turbine unit and the regenerator of the power plant unit, and the driving flow path and the heat exchange flow path are arranged in parallel with each other. The driving flow path and the heat exchange flow path are respectively connected to the energy storage flow path and the energy release flow path of the liquid air energy storage unit. The power station uses the first steam turbine unit of the power plant unit to do work at any power consumption stage of the power grid to realize normal power transmission to the power grid. Moreover, at the valley stage of power consumption of the power grid, the driving flow path can be used to extract inter-stage steam from the first steam turbine unit to drive the operation of the energy storage flow path. And at the peak stage of power consumption of the power grid, the heat exchange flow path can be used to extract inter-stage steam from the first steam turbine unit to exchange heat with the medium in the energy release flow path to preheat the medium in the energy release flow path in the energy release power generation state. It can be seen that the power station can flexibly adjust the peak according to the power consumption load stage of the power grid. During the peak shaving process, on the one hand, the inter-stage steam of the first steam turbine unit extracted by the driving flow path can be directly used to drive the liquid air energy storage unit to realize energy storage. On the other hand, the inter-stage steam of the first steam turbine unit extracted by the heat exchange flow path can be used to preheat the medium in the energy release flow path in the energy release power generation state, thereby reducing the energy conversion process of "steam - generator - electric energy - motor - air compressor" in the prior art, improving the energy release efficiency of the liquid air energy storage unit, effectively improving the overall operation efficiency of the power station, and reducing the operation cost of the power station.

[0032] In other words, on the basis of the traditional peak shaving thermal power plant, this power station combines a liquid air energy storage unit. At the valley stage of power consumption of the power grid, it is not necessary to change the steam parameters of the steam boiler. Instead, part of the low-pressure steam is extracted from the inter-stage of the first steam turbine unit to drive the operation of the second steam turbine unit, and then drive the liquid air energy storage unit to store energy. At the peak stage of power consumption of the power grid, it is also not necessary to change the steam parameters of the steam boiler. Instead, the power is output by the liquid air energy storage unit, and part of the low-pressure steam is extracted from the inter-stage of the second steam turbine unit to preheat the intake air of the air turbine unit, thereby increasing the power generation. This setting can not only increase the peak shaving capacity range of the power plant unit to 30% - 200% of the rated power, so as to realize high-power deep peak shaving, but also can always maintain the steam boiler running under the rated working condition without shutdown. While improving the operation efficiency of the thermal power plant, the quick response of peak shaving and valley filling can be realized through the start and stop of the liquid air energy storage unit. Moreover, through the extraction of inter-stage steam from the first steam turbine unit, the power station can effectively reduce the flow rate at the low-pressure end of the first steam turbine unit, and then reduce the length of the last-stage blade of the first steam turbine unit, improving the efficiency of the first steam turbine unit.

[0033] Specifically, due to the limitations of their own technical characteristics, the existing traditional thermal power plants have a peak shaving capacity range of only 50% - 100%, and the peak shaving efficiency is low, and the response speed is too slow. Compared with the existing thermal power plants, the peak shaving capacity range of the power station described in the present invention can reach 30% - 200%, effectively expanding the peak shaving range, and having high peak shaving efficiency and fast response speed.

[0034] Furthermore, during the construction process of this power station, since the power plant unit and the liquid air energy storage unit can share a large number of public engineering facilities, that is, the facilities can be directly transformed on the basis of the original thermal power plant. Therefore, compared with the construction of the liquid air energy storage power station in the prior art, the initial investment in the power station transformation can be significantly reduced, and the construction cost can be lowered.

[0035] The present invention also provides a deep peak shaving method, which is executed by the deep peak shaving power station combined with liquid air energy storage described above, so that the deep peak shaving method has all the advantages of the deep peak shaving power station combined with liquid air energy storage described above, and will not be elaborated here specifically. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0037] Figure 1 It is a schematic structural diagram of the deep peak shaving power station combined with liquid air energy storage provided by the present invention.

[0038] Reference Numerals:

[0039] 1: Steam boiler; 2: First steam turbine unit; 3: Condenser;

[0040] 4: Primary feed water pump; 5: Regenerator; 6: Secondary feed water pump;

[0041] 7: Second steam turbine unit; 8: First control valve; 9: Second control valve;

[0042] 10: Third control valve; 11: Fourth control valve; 12: Air compressor unit;

[0043] 13: Compressed heat utilization device; 14: Cold storage regenerator; 15: Throttling element;

[0044] 16: Energy storage tank; 17: Driving pump; 18: Air preheater;

[0045] 19: Air turbine unit; 20: First transmission line; 21: Second transmission line;

[0046] 22: Power grid; 23: First generator; 24: Second generator. Detailed implementation manners

[0047] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0048] The following will be described in conjunction with Figure 1 a deep peak shaving power station combined with liquid air energy storage of the present invention (the embodiment of the present invention may be simply referred to as "power station" or "deep peak shaving power station"), and a deep peak shaving method implemented by the power station.

[0049] As Figure 1 shown, the deep peak shaving power station includes a driving flow path and a heat exchange flow path. The driving flow path is bypass-connected between the first steam turbine unit 2 and the regenerator 5 of the power plant unit. Among them, the first steam turbine unit 2 and the regenerator 5 are connected in the same steam circulation flow path; the heat exchange flow path is bypass-connected between the first steam turbine unit 2 and the regenerator 5 and is arranged in parallel with the driving flow path. Among them, the first steam turbine unit 2 is used to transmit power to the power grid 22; when the power grid 22 is in the valley period of power consumption, the driving flow path can extract intermediate steam from the first steam turbine unit 2 to drive the energy storage flow path of the liquid air energy storage unit to operate; when the power grid 22 is in the peak period of power consumption, the heat exchange flow path can extract intermediate steam from the first steam turbine unit 2 to exchange heat with the energy release flow path of the liquid air energy storage unit to preheat the medium in the energy release flow path in the energy release power generation state.

[0050] In other words, the power station bypass-connects the driving flow path and the heat exchange flow path between the first steam turbine unit 2 and the regenerator 5 of the power plant unit, and arranges the driving flow path and the heat exchange flow path in parallel with each other. The driving flow path and the heat exchange flow path are respectively connected to the energy storage flow path and the energy release flow path of the liquid air energy storage unit; the power station uses the first steam turbine unit 2 of the power plant unit to do work at any power consumption stage of the power grid 22 to realize normal power transmission to the power grid 22; and, when the power grid 22 is in the valley period of power consumption, the driving flow path can be used to extract intermediate steam from the first steam turbine unit 2 to drive the energy storage flow path to operate; and, when the power grid 22 is in the peak period of power consumption, the heat exchange flow path can be used to extract intermediate steam from the first steam turbine unit 2 to exchange heat with the medium in the energy release flow path to preheat the medium in the energy release flow path in the energy release power generation state.

[0051] It can be seen that the power station can flexibly adjust the peak load according to the power consumption load stage of the power grid 22. During the peak load adjustment process, on the one hand, the inter-stage steam of the first steam turbine unit 2 extracted by the driving flow path can be directly used to drive the liquid air energy storage unit to achieve energy storage. On the other hand, the inter-stage steam of the first steam turbine unit 2 extracted by the heat exchange flow path can be used to preheat the medium in the energy release flow path in the energy release power generation state, thereby reducing the energy conversion process of "steam - generator - electric energy - motor - air compressor" in the prior art, improving the energy release efficiency of the liquid air energy storage unit, effectively improving the overall operation efficiency of the power station, reducing the operation cost of the power station, and having the advantages of a wide peak load adjustment range, high peak load adjustment efficiency, and fast response speed.

[0052] In some embodiments, the power plant unit includes a steam boiler 1, the above-mentioned first steam turbine unit 2, a condenser 3, a first feed water pump 4, the above-mentioned regenerator 5, and a second feed water pump 6. The steam boiler 1, the first steam turbine unit 2, the condenser 3, the first feed water pump 4, the regenerator 5, and the second feed water pump 6 are sequentially connected in the same steam cycle flow path to form a power generation cycle of a power plant for steam work.

[0053] It can be understood that the first steam turbine unit 2 is connected to a first generator 23, and the first generator 23 is connected to the power grid 22 through a first transmission line 20. The first steam turbine unit 2 drives the first generator 23 to generate electricity by doing work, and thus transmits electricity to the power grid 22 through the first transmission line 20.

[0054] It can be understood that the power plant unit is preferably a peak load regulating thermal power plant. Further, the power plant unit is preferably a condensing peak load regulating thermal power plant or a thermal power plant.

[0055] It can be understood that the steam boiler 1 is preferably at least one of a coal-fired boiler, a gas-fired boiler, and a waste heat boiler.

[0056] It can be understood that the structural form of the first steam turbine unit 2 is preferably radial flow, axial flow, or radial-axial flow. Preferably, the first steam turbine unit 2 includes one or more steam turbines, and each steam turbine is integrated by series connection, parallel connection, or series-parallel connection to form the first steam turbine unit 2. The inter-stage of the first steam turbine unit 2 refers to between two adjacent steam turbines. Preferably, a preheater is arranged in front of each stage of the steam turbine.

[0057] In some embodiments, such as Figure 1As shown, a second steam turbine unit 7 is provided on the driving flow path. The liquid air energy storage unit includes an air compressor unit 12 and an energy storage tank 16. The energy storage flow path is connected between the air compressor unit 12 and the energy storage tank 16. The power output shaft end of the second steam turbine unit 7 is connected to the power input shaft end of the air compressor unit 12. Enabling the driving flow path can introduce the inter-stage steam of the first steam turbine unit 2 into the second steam turbine unit 7, thereby driving the second steam turbine unit 7 to operate and directly driving the air compressor unit 12 to operate through mechanical energy, so as to compress the air entering the air compressor unit 12, and further realize and complete the energy storage stage of the liquid air energy storage unit.

[0058] It can be understood that preferably, the structural form of the second steam turbine unit 7 is preferably radial flow type, axial flow type or radial-axial flow type. Preferably, the second steam turbine unit 7 includes one or more steam turbines, and each steam turbine is integrated by series connection, parallel connection or series-parallel connection to form the second steam turbine unit 7. Preferably, a preheater is arranged in front of each stage of the steam turbine.

[0059] It can be understood that in order to improve the driving efficiency of the driving flow path and reliably control the steam flowing through the driving flow path to achieve efficient driving of the air compressor unit 12, preferably, the inter-stage extraction steam pressure of the driving flow path for the first steam turbine unit 2 is controlled between 1 bar and 10 bar.

[0060] In some embodiments, the liquid air energy storage unit further includes an air turbine unit 19 and an air preheater 18. The energy release flow path is connected between the energy storage flow path and the air turbine unit 19. Preferably, the air turbine unit 19 is connected with a second generator 24, and the second generator 24 can transmit power to the power grid 22 through a power transmission pipeline. The first heat exchange side of the air preheater 18 is connected to the energy release flow path, and the second heat exchange side of the air preheater 18 is connected to the heat exchange flow path, so that the steam in the heat exchange flow path exchanges heat with the air in the energy release flow path in the air preheater 18, achieving the effect of preheating the medium in the energy release pipeline of the liquid air energy storage unit by using the inter-stage steam of the first steam turbine unit 2, further increasing the working efficiency and work output of the air turbine unit 19, and thus increasing the power generation of the second generator 24.

[0061] In some embodiments, the liquid air energy storage unit further includes a compressed heat utilization device 13, a cold accumulator 14, a throttling element 15, and a driving pump 17. The first heat exchange side and the second heat exchange side of the compressed heat utilization device 13 are respectively connected to the energy storage flow path and the energy release flow path. The compressed heat utilization device 13 can utilize the compressed heat of the compressed air stored during the energy storage stage of the liquid air energy storage unit to heat and raise the temperature of the air flowing through the compressed heat utilization device 13 during the energy release stage of the liquid air energy storage unit. The first heat exchange side of the cold accumulator 14 is connected to the energy storage flow path between the compressed heat utilization device 13 and the energy storage tank 16, and the second heat exchange side of the cold accumulator 14 is connected to the energy release flow path between the energy storage tank 16 and the compressed heat utilization device 13. The cold accumulator 14 can retain the cold of the liquid air flowing through the cold accumulator 14 during the energy release stage of the liquid air energy storage unit, thereby cooling the normal temperature and high-pressure air flowing through the cold accumulator 14 during the energy storage stage of the liquid air energy storage unit. The throttling element 15 is connected to the energy storage flow path between the first heat exchange side of the cold accumulator 14 and the energy storage tank 16. The throttling element 15 can step down and expand the cooled low-temperature and high-pressure air during the energy storage stage to convert the air into liquid air. The driving pump 17 is connected to the energy release flow path between the energy storage tank 16 and the second heat exchange side of the cold accumulator 14. The driving pump 17 can achieve start-stop response according to the control signal of the power grid 22 to enable the energy release flow path of the liquid air energy storage unit in a timely manner when the power grid 22 enters the peak electricity consumption period, so that the liquid air in the energy storage tank 16 enters the cold accumulator 14 after being pressurized by the driving pump 17.

[0062] It is understandable that the structure of the air compressor unit 12 is preferably piston type, screw type or centrifugal type. Preferably, the air compressor unit 12 includes one or more compressors. Each compressor is integrated by series connection, parallel connection or series-parallel connection to form the air compressor unit 12. A compressed heat utilization device 13 can be configured after each stage of the compressor.

[0063] It is understandable that the structural form of the air turbine unit 19 is preferably radial flow type, axial flow type or radial-axial flow type. Preferably, the air turbine unit 19 includes one or more turbines, and each turbine is integrated by series connection, parallel connection or series-parallel connection to form the air turbine unit 19. Preferably, a preheater is configured before each stage of the turbine.

[0064] It is understandable that the air preheater 18 is preferably one or a combination of a shell-and-tube structure, a plate-fin structure and a wound-tube structure.

[0065] It is understandable that the compressed heat utilization device 13 can not only use the stored compressed heat to preheat the intake air of the air turbine unit 19, but also be used for domestic hot water, heating water or driving an absorption refrigeration unit for cooling. For example, the compressed heat utilization device 13 is set as a lithium bromide unit or an ammonia water unit.

[0066] It is understandable that the cold storage device 14 preferably adopts one or a combination of a liquid-phase cold storage device 14, a solid-phase cold storage device 14, or a phase change material cold storage device 14. The cold storage medium of the liquid-phase cold storage device 14 is preferably at least one of methanol, propane, and R123. The cold storage medium of the solid-phase cold storage device 14 is preferably at least one of metal, rock, and glass. Preferably, inside the cold storage device 14, the liquid or gaseous air is in direct or indirect contact heat exchange with the cold storage medium. Preferably, the cold storage device 14 includes one or more stages of cold storage machines, and each stage of cold storage machines is constituted by series connection, parallel connection, or a series-parallel combination.

[0067] It is understandable that the throttling element 15 is preferably a cryogenic expander or a throttle valve.

[0068] It is understandable that the energy storage tank 16 is preferably a Dewar flask or a cryogenic storage tank.

[0069] It is understandable that the pump body structure of the driving pump 17 is preferably piston type or centrifugal type.

[0070] It is understandable that the control signal of the power grid 22 can be the dispatching instruction signal of the power grid 22 or the internal dispatching instruction signal of the power plant unit.

[0071] In some embodiments, preferably, at least one control valve is provided on each of the driving flow path and the heat exchange flow path, and each control valve is signal-connected to the power grid 22 respectively. The control valve can flexibly control the flow rate and flow velocity of the steam extracted from the interstage of the first steam turbine unit 2, so that it is not necessary to control the parameters of the steam boiler 1 of the power plant unit, simplifies the control process, and prolongs the service life of the steam boiler 1.

[0072] Specifically, at least one first control valve 8 is provided on the connecting pipeline between the steam inlet end of the second steam turbine unit 7 and the first steam turbine unit 2; and / or, at least one second control valve 9 is provided on the connecting pipeline between the steam exhaust end of the second steam turbine unit 7 and the regenerator 5. At least one third control valve 10 is provided on the connecting pipeline between the steam inlet end of the second heat exchange side of the air preheater 18 and the first steam turbine unit 2; and / or, at least one fourth control valve 11 is provided on the connecting pipeline between the steam exhaust end of the second heat exchange side of the air preheater 18 and the regenerator 5.

[0073] Such as Figure 1As shown in the figure, in the power station described in this embodiment, a first control valve 8 is provided on the connecting pipeline between the steam inlet end of the second steam turbine unit 7 and the first steam turbine unit 2, and a second control valve 9 is provided on the connecting pipeline between the steam exhaust end of the second steam turbine unit 7 and the regenerator 5. A third control valve 10 is provided on the connecting pipeline between the steam inlet end of the second heat exchange side of the air preheater 18 and the first steam turbine unit 2, and a fourth control valve 11 is provided on the connecting pipeline between the steam exhaust end of the second heat exchange side of the air preheater 18 and the regenerator 5. This setting can not only achieve the combined regulation of the driving flow path and the heat exchange flow path, but also improve safety.

[0074] The present invention also provides a deep peak shaving method, which is executed by the above-mentioned deep peak shaving power station combined with liquid air energy storage, so that the deep peak shaving method has all the advantages of the above-mentioned deep peak shaving power station combined with liquid air energy storage. The advantages of the deep peak shaving method will not be elaborated here specifically.

[0075] In this deep peak shaving method, the power grid 22 is divided into a flat power consumption section, a valley power consumption section, and a peak power consumption section according to the power consumption load. Among them, the flat power consumption section refers to the range where the power consumption load of the power grid 22 is at an average level, and this average level range is comprehensively evaluated based on actual power consumption load data such as the overall power consumption load of users in the location of the power grid 22, the annual average power consumption load, the monthly average power consumption load, and the daily average power consumption load. The valley power consumption section refers to the stage where the power grid 22 is in a stage where the power consumption load is lower than the average level range, and the peak power consumption section refers to the stage where the power grid 22 is in a stage where the power consumption load is higher than the average level range.

[0076] In this deep peak shaving method, when the power grid 22 is in the flat power consumption section, both the driving flow path and the heat exchange flow path are in a closed state, and the power plant unit generates electricity for the power grid 22 by the work of the first steam turbine unit 2.

[0077] Specifically, as Figure 1 shown, when the power grid 22 is in the flat power consumption section, the steam circulation flow path of the power plant unit operates normally, that is, the steam boiler 1 operates at a rated power to use the high-pressure steam generated by the steam boiler 1 to drive the first steam turbine unit 2 to operate stably at a rated power, and then drive the first generator 23 to generate electricity, so as to transmit the generated electric energy to the power grid 22 through the first transmission line 20; the exhaust steam generated by the first steam turbine unit 2 enters the condenser 3 and is condensed into a liquid state, and after being pressurized by the first stage feed water pump 4, it enters the steam boiler 1 to be reheated to generate high-pressure steam. In the flat power consumption section, the liquid air energy storage unit does not operate.

[0078] In this deep peak shaving method, when the power grid 22 is in the valley power consumption section, the power plant unit generates electricity for the power grid 22 by the work of the first steam turbine unit 2, and the driving flow path is opened to drive the intermediate stage steam of the first steam turbine unit 2 to drive the energy storage flow path of the liquid air energy storage unit to operate.

[0079] Specifically, as Figure 1 shown, when the power grid 22 is in the off-peak power consumption period, the steam boiler 1 still operates at the rated power to transmit power to the power grid 22. The specific operation will not be elaborated here. Both the first control valve 8 and the second control valve 9 are opened to start the driving flow path, so as to extract part of the low-pressure steam from the inter-stage of the first steam turbine unit 2 through the driving flow path to drive the second steam turbine unit 7 to operate, and the opening degrees of the first control valve 8 and the second control valve 9 are used to respectively or cooperatively achieve flexible adjustment of the steam flow rate and velocity in the driving flow path; the second steam turbine unit 7 drives the air compressor unit 12 of the liquid air energy storage unit to operate through rotation, so as to compress the normal temperature and pressure air to medium temperature and high pressure, and the medium temperature compression heat is recovered and utilized through the compression heat utilization device 13, and then the high-pressure air cooled to normal temperature enters the cold storage device 14 and is cooled to a low temperature. After being depressurized and expanded by the throttling element 15, the generated liquid air is stored in the energy storage tank 16, thus completing the energy storage process of the energy storage flow path of the liquid air energy storage unit.

[0080] In this deep peak shaving method, when the power grid 22 is in the peak power consumption period, the energy release flow path of the liquid air energy storage unit is driven to operate to generate power for the power grid 22, and the power plant unit is driven to generate power for the power grid 22 through the work of the first steam turbine unit 2, and the heat exchange flow path is opened to drive the inter-stage steam of the first steam turbine unit 2 to exchange heat with the medium in the energy release flow path.

[0081] Specifically, as Figure 1 shown, when the power grid 22 is in the peak power consumption period, the steam boiler 1 still operates at the rated power to transmit power to the power grid 22. The specific operation will not be elaborated here. When the power grid 22 judges that it is in the peak power consumption period, the driving pump 17 of the liquid air energy storage unit is started through a control signal, so that the liquid air in the energy storage tank 16 enters the cold storage device 14 after being pressurized by the driving pump 17, and the cold quantity of the liquid air is retained in the cold storage device 14 for use in the energy storage stage. The reheated high-pressure air enters the air preheater 18 after being heated by the compression heat utilization device 13; at the same time, both the third control valve 10 and the fourth control valve 11 are opened to enable the heat exchange flow path, so as to extract part of the low-pressure steam from the inter-stage of the first steam turbine unit 2 through the heat exchange flow path and enter the air preheater 18 to exchange heat with the high-pressure air flowing through the air preheater 18 and being in the energy release flow path of the liquid air energy storage unit, so that the high-pressure air is preheated in the air preheater 18; the opening degrees of the third control valve 10 and the fourth control valve 11 are used to respectively or cooperatively achieve flexible adjustment of the steam flow rate and velocity in the heat exchange flow path. The preheated high-pressure air enters the air turbine unit 19 to expand and do work to drive the second generator 24 to generate power, and the generated electric energy is transmitted to the power grid 22 through the second transmission line 21, thus completing the energy release process of the energy release flow path of the liquid air energy storage unit.

[0082] It is understandable that preferably during the low - consumption period of the power grid 22, the power transmission process of the power plant unit and the energy storage process of the liquid air energy storage unit can be parallel, or there can be a sequential timing or intermittent operation with each other; preferably during the peak - consumption period of the power grid 22, the power transmission process of the power plant unit and the energy - release process of the liquid air energy storage unit can be parallel, or there can be a sequential timing or intermittent operation with each other.

[0083] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of 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 thus cannot be understood as a limitation to the embodiments of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0084] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "connected" and "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific situations.

[0085] In the embodiments of the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0086] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc., mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A deep peak shaving power station combined with liquid air energy storage, characterized in that, Comprising: A driving flow path, which is bypass-connected between the first steam turbine unit and the regenerator of the power plant unit. Wherein, the first steam turbine unit and the regenerator are connected in the same steam circulation flow path, and the steam circulation flow path forms a power generation cycle of a power plant for steam to do work and generate electricity; A heat exchange flow path, which is bypass-connected between the first steam turbine unit and the regenerator and is arranged in parallel with the driving flow path; Wherein, the first steam turbine unit is used for transmitting electricity to the power grid; A second steam turbine unit is provided on the driving flow path. The liquid air energy storage unit includes an air compressor unit and an energy storage tank. The energy storage flow path is connected between the air compressor unit and the energy storage tank. The power output shaft end of the second steam turbine unit is connected to the power input shaft end of the air compressor unit; When the power grid is in the off-peak electricity consumption period, the steam parameters of the steam boiler in the steam circulation flow path remain unchanged, and the driving flow path can extract inter-stage steam from the first steam turbine unit to drive the operation of the energy storage flow path of the liquid air energy storage unit; When the power grid is in the peak electricity consumption period, the steam parameters of the steam boiler in the steam circulation flow path remain unchanged, and the heat exchange flow path can extract inter-stage steam from the first steam turbine unit to exchange heat with the energy release flow path of the liquid air energy storage unit to preheat the medium in the energy release flow path in the energy release power generation state.

2. The deep peak shaving power station combined with liquid air energy storage according to claim 1, characterized in that The liquid air energy storage unit further includes an air turbine unit and an air preheater. The energy release flow path is connected between the energy storage flow path and the air turbine unit; The first heat exchange side of the air preheater is connected to the energy release flow path, and the second heat exchange side of the air preheater is connected to the heat exchange flow path.

3. The deep peak shaving power station combined with liquid air energy storage according to claim 2, wherein At least one control valve is respectively provided on the driving flow path and the heat exchange flow path, and each control valve is respectively in signal connection with the power grid.

4. The deep peak shaving power station combined with liquid air energy storage according to claim 3, wherein, At least one first control valve is provided on the connecting pipeline between the steam inlet end of the second steam turbine unit and the first steam turbine unit; and / or, At least one second control valve is provided on the connecting pipeline between the steam exhaust end of the second steam turbine unit and the regenerator.

5. The deep peak shaving power station combined with liquid air energy storage according to claim 3, characterized in that, At least one third control valve is provided on the connecting pipeline between the steam inlet end of the second heat exchange side of the air preheater and the first steam turbine unit; and / or, At least one fourth control valve is provided on the connecting pipeline between the steam exhaust end of the second heat exchange side of the air preheater and the regenerator.

6. The deep peak shaving power station combined with liquid air energy storage according to claim 2, wherein The liquid air energy storage unit further includes: A compressed heat utilization device, whose first heat exchange side and second heat exchange side are respectively connected to the energy storage flow path and the energy release flow path; A cold accumulator, whose first heat exchange side is connected to the energy storage flow path between the compressed heat utilization device and the energy storage tank, and the second heat exchange side of the cold accumulator is connected to the energy release flow path between the energy storage tank and the compressed heat utilization device; A throttling element, which is connected to the energy storage flow path between the first heat exchange side of the cold accumulator and the energy storage tank; A driving pump, which is connected to the energy release flow path between the energy storage tank and the second heat exchange side of the cold accumulator.

7. The deep peak shaving power station combined with liquid air energy storage according to claim 2, characterized in that, The first steam turbine unit is connected to a first generator, and the air turbine unit is connected to a second generator. The first generator and the second generator can each transmit electricity to the power grid through power transmission pipelines respectively.

8. The deep peak shaving power station combined with liquid air energy storage according to any one of claims 1 to 7, characterized in that The power plant unit includes a steam boiler, a condenser, a first feed water pump, and a second feed water pump. The steam boiler, the first steam turbine unit, the condenser, the first feed water pump, the regenerator, and the second feed water pump are sequentially connected in the same steam circulation flow path.

9. A deep peak shaving method, characterized in that, It is executed by the deep peak shaving power station integrating liquid air energy storage according to any one of claims 1 to 8; the deep peak shaving method includes: The power grid is divided into a flat electricity consumption section, a valley electricity consumption section, and a peak electricity consumption section according to the electricity consumption load. When the power grid is in the flat electricity consumption section, both the drive flow path and the heat exchange flow path are in a closed state, and the power plant unit generates electricity for the power grid by the work of the first steam turbine unit. When the power grid is in the valley electricity consumption section, the power plant unit generates electricity for the power grid by the work of the first steam turbine unit, and the drive flow path is opened to drive the inter-stage steam of the first steam turbine unit to drive the energy storage flow path of the liquid air energy storage unit to operate. When the power grid is in the peak electricity consumption section, the energy release flow path of the liquid air energy storage unit is driven to operate to generate electricity for the power grid, and the power plant unit is driven to generate electricity for the power grid by the work of the first steam turbine unit, and the heat exchange flow path is opened to drive the inter-stage steam of the first steam turbine unit to exchange heat with the medium in the energy release flow path.

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